lipid-a and Neoplasms

Toll-like Receptor 4 (TLR4) agonists have had a long journey in the field of cancer immunotherapy. Nevertheless, despite the remarkable number of the TLR4 ligands that have gone through various preclinical and clinical stages, only two (Bacillus Calmette-Guérin (BCG) and monophosphoryl lipid A (MPLA)) have hitherto obtained the FDA approval for clinical application in cancer treatment. This paper provides a comprehensive review of the TLR4 agonists' journey as cancer active immunotherapeutics. Following a brief discussion of the rationale behind the use of TLR ligands in cancer immunotherapy, we will initially focus on the forerunner of the TLR4 agonists, bacterial lipopolysaccharide (LPS). Within this context, the potentials and shortcomings of immunotherapy with this agent will be addressed, the strategies that have been devised to enhance the associated therapeutic outcome will be discussed, and the consequent achievements and shortcomings will be summarized. Subsequently, further and perhaps less well-known, molecular, bacterial, and viral TLR4 agonists with potential for cancer immunotherapy will be introduced, and if present, the outcome of the preclinical and clinical investigations of these agents will be reviewed. Finally, a look will be cast upon the promising souvenirs of the relatively new arena of nanotechnology, where TLR4 activating nanoparticulate systems will be proposed as potential candidates for the future development of this field.

Topics: Adjuvants, Immunologic; Animals; BCG Vaccine; Clinical Trials as Topic; Drug Evaluation, Preclinical; Humans; Immunity, Innate; Immunotherapy; Ligands; Lipid A; Nanoparticles; Neoplasms; Oncolytic Viruses; Respiratory Syncytial Viruses; Toll-Like Receptor 4; Treatment Outcome

Reduced rates of lung cancer have been observed in several occupational groups exposed to high levels of organic dusts contaminated by endotoxin. The underlying anti-neoplastic mechanism of endotoxin may be an increased secretion of endogenous anti-neoplastic mediators and activation of the toll-like receptors (TLR). A detoxified endotoxin derivative, Monophosphoryl Lipid A (MPL(®)) is marketed in Europe since 1999 as part of the adjuvant systems in allergy vaccines for treatment of allergic rhino-conjunctivitis and allergic asthma. Over 200,000 patients have used them to date (nearly 70% in Germany). Since detailed exposure (MPL(®) dose and timing of administration) and individual data are potentially available, an observational follow-up study could be conducted in Germany to investigate the protective effect of MPL(®) against cancer, comparing cancer incidence in two groups of patients with allergic rhinitis: those treated with allergoids plus MPL(®) and those treated with a vaccine including the same allergoids but not MPL(®). The protective effect of MPL(®) could be quantified in ever and never smokers. If this proposed observational study provides evidence of protective effects, MPL(®) could be immediately used as a chemo-preventive agent since it is already in use as adjuvant in human vaccines against cancer.

Topics: Anticarcinogenic Agents; Endotoxins; Humans; Lipid A; Neoplasms; Occupational Diseases; Occupational Exposure

Hypoxia is a common feature of the tumor microenvironment and a major cause of clinical radioresistance. During the last decades, several strategies to improve tumor oxygenation were developed such as breathing high oxygen content gas under hyperbaric conditions (3 atmosphere) and improving tumor perfusion by nicotinamide, in combination with carbogen breathing and accelerated radiotherapy to counteract tumor repopulation (ARCON). Other strategies to overcome hypoxia induced radioresistance are the use of hypoxic cell radiosensitizers, which mimic oxygen and enhance thereby radiation damage (e.g. the nitroimidazoles) and bioreductive drugs, which undergo intracellular reduction to form active cytotoxic species under low oxygen tension (e.g. mitomycin C and tirapazamine). A meta-analysis of all randomized trials in which some form of hypoxic modification was performed, showed an improved local control and survival, especially in cervix and head-and-neck cancer. Nevertheless, none of the discussed strategies are used in clinical routine because of feasibility and toxicity issues. We developed an alternative strategy that takes advantage of the microenvironment of solid tumors for tumor specific radiosensitization. The inducible isoform of nitric oxide synthase (iNOS) may be induced by bacterial LPS or its derivate lipid A, is expressed by a variety of solid tumors and generates NO at high rates inside tumor cells. This local production of NO results in efficient hypoxic tumor cell radiosensitization, at non-toxic extracellular concentrations of NO. In addition, iNOS is transcriptionally upregulated by hypoxia and proinflammatory cytokines such as interferon-gamma. Hence, we proposed the pro-inflammatory tumor infiltrate as a new target for radiosensitizing strategies and identified two mechanisms: First, tumor associated immune cells (macrophages, T/NK-cells) are a source of mediators that may induce the iNOS/NO pathway inside tumor cells. Second, tumor associated macrophages can produce high levels of NO that may radiosensitize bystander tumor cells. Our ongoing research is focused on combining immunostimulatory and radiosensitizing strategies.

Topics: Animals; Cell Hypoxia; Cell Line, Tumor; Enzyme Activation; Interleukins; Killer Cells, Natural; Lipid A; Macrophages; Mice; Neoplasms; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase Type II; Oxygen; Partial Pressure; Radiation Tolerance; Radiation-Sensitizing Agents; Tumor Necrosis Factor-alpha

Liver or lung metastases usually relapse under chemotherapy. Such life-threatening condition urgently needs new, systemic anticancer compounds, with original and efficient mechanisms of action. In B16 melanoma mice treated with cyclophosphamide, D'Agostini et al. [D'Agostini, C., Pica, F., Febbraro, G., Grelli, S., Chiavaroli, C., Garaci, E., 2005. Antitumour effect of OM-174 and Cyclophosphamide on murine B16 melanoma in different experimental conditions. Int. Immunopharmacol. 5, 1205-1212.] recently found that OM-174, a chemically defined Toll-like receptor(TLR)2/4 agonist, reduces tumor progression and prolongs survival. Here we review 149 articles concerning molecular mechanisms of TLR2/4 agonists, alone or in combination with chemotherapy. It appears that TLR2/4 agonists induce a well controlled tumor necrosis factor-alpha (TNF-alpha) secretion, at plasma levels known to permeabilize neoangiogenic tumor vessels to the passage of cytotoxic drugs. Moreover, TLR2/4 agonists induce inducible nitric oxide synthase (iNOS) expression, and nitric oxide is able to induce apoptosis of chemotherapy-resistant tumor cell clones. Finally, TLR2/4-stimulation activates dendritic cell traffic and its associated tumor-specific, cytotoxic T-cell responses. Therefore, parenteral TLR2/4 agonists seem promising molecules to prolong survival in cancer patients who relapse under chemotherapy.

Topics: Animals; Antineoplastic Agents; Apoptosis; BCG Vaccine; Chemotherapy, Adjuvant; Dendritic Cells; Drug Resistance, Neoplasm; Enzyme Induction; Humans; Immunotherapy; Interleukin-10; Lipid A; Lipopolysaccharides; Neoadjuvant Therapy; Neoplasms; Nitric Oxide Synthase Type II; Recurrence; Signal Transduction; T-Lymphocytes, Cytotoxic; Toll-Like Receptor 2; Toll-Like Receptor 4; Treatment Outcome; Tumor Necrosis Factor-alpha

Topics: Adjuvants, Immunologic; Animals; Antineoplastic Agents; Clinical Trials as Topic; Disease Models, Animal; Humans; Lipid A; Neoplasms; Neoplasms, Experimental; Vaccination

Topics: Animals; Bacterial Toxins; Cobalt Radioisotopes; Endotoxins; Humans; Immunity, Innate; Lipid A; Neoplasms; Shock, Septic

A phase I trial (NCT03447314; 204686) evaluated the safety and efficacy of GSK1795091, a Toll-like receptor 4 (TLR4) agonist, in combination with immunotherapy (GSK3174998 [anti-OX40 monoclonal antibody], GSK3359609 [anti-ICOS monoclonal antibody], or pembrolizumab) in patients with solid tumors. The primary endpoint was safety; other endpoints included efficacy, pharmacokinetics, and pharmacodynamics (PD). Manufacturing of GSK1795091 formulation was modified during the trial to streamline production and administration, resulting in reduced PD (cytokine) activity. Fifty-four patients received GSK1795091 with a combination partner; 32 received only the modified GSK1795091 formulation, 15 received only the original formulation, and seven switched mid-study from the original to the modified formulation. Despite the modified formulation demonstrating higher systemic GSK1795091 exposure compared with the original formulation, the transient, dose-dependent elevations in cytokine and chemokine concentrations were no longer observed (e.g., IP-10, IL10, IL1-RA). Most patients (51/54; 94%) experienced ≥1 treatment-emergent adverse event (TEAE) during the study. Safety profiles were similar between formulations, but a higher incidence of TEAEs associated with immune responses (chills, fatigue, pyrexia, nausea, and vomiting) were observed with the original formulation. No conclusions can be made regarding GSK1795091 anti-tumor activity due to the limited data collected. Manufacturing changes were hypothesized to have caused the change in biological activity in this study. Structural characterization revealed GSK1795091 aggregate size in the modified formulation to be twice that in the original formulation, suggesting a negative correlation between GSK1795091 aggregate size and PD activity. This may have important clinical implications for future development of structurally similar compounds.

Topics: Antibodies, Monoclonal; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cytokines; Humans; Lipid A; Neoplasms; Toll-Like Receptor 4

Human tumor cells express antigens that serve as targets for the host cellular immune system. This phase 1 dose-escalating study was conducted to assess safety and tolerability of G305, a recombinant NY-ESO-1 protein vaccine mixed with glucopyranosyl lipid A (GLA), a synthetic TLR4 agonist adjuvant, in a stable emulsion (SE). Twelve patients with solid tumors expressing NY-ESO-1 were treated using a 3 + 3 design. The NY-ESO-1 dose was fixed at 250 µg, while GLA-SE was increased from 2 to 10 µg. Safety, immunogenicity, and clinical responses were assessed prior to, during, and at the end of therapy. G305 was safe and immunogenic at all doses. All related AEs were Grade 1 or 2, with injection site soreness as the most commonly reported event (100%). Overall, 75% of patients developed antibody response to NY-ESO-1, including six patients with increased antibody titer ( ≥ 4-fold rise) and three patients with seroconversion from negative (titer < 100) to positive (titer ≥ 100). CD4 T-cell responses were observed in 44.4% of patients; 33.3% were new responses and 1 was boosted ( ≥ 2-fold rise). Following treatment, 8 of 12 patients had stable disease for 3 months or more; at the end of 1 year, three patients had stable disease and nine patients were alive. G305 is a potent immunotherapeutic agent that can stimulate NY-ESO-1-specific antibody and T-cell responses. The vaccine was safe at all doses of GLA-SE (2-10 µg) and showed potential clinical benefit in this population of patients.

Topics: Adjuvants, Immunologic; Adult; Aged; Antigens, Neoplasm; Cancer Vaccines; CD4-Positive T-Lymphocytes; Drugs, Investigational; Female; Glucosides; Humans; Immunogenicity, Vaccine; Injections, Intramuscular; Lipid A; Male; Membrane Proteins; Middle Aged; Neoplasms; Recombinant Proteins; Toll-Like Receptor 4; Treatment Outcome; Vaccines, Synthetic; Young Adult

Fifty-seven patients with MAGE-3-positive measurable metastatic cancer, most of them with melanoma, were vaccinated with escalating doses of a recombinant MAGE-3 protein combined with a fixed dose of the immunological adjuvant SBAS-2, which contained MPL and QS21. The immunisation schedule included 4 intramuscular (i.m.) injections at 3-week intervals. Patients whose tumour stabilised or regressed after 4 vaccinations received 2 additional vaccinations at 6-week intervals. The vaccine was generally well tolerated. Among the 33 melanoma patients who were evaluable for tumour response, we observed 2 partial responses, 2 mixed responses and 1 stabilisation. Time to progression in these 5 patients varied from 4 to 29 months. In addition, a partial response lasting 10 months was observed in 1 of the 3 metastatic bladder cancer patients included. None of the tumour responses described above involved visceral metastases. Immunological responses to the vaccine will be reported separately.

Topics: Adjuvants, Immunologic; Adult; Aged; Antigens, Neoplasm; Antineoplastic Combined Chemotherapy Protocols; Cancer Vaccines; Carcinoma, Non-Small-Cell Lung; Carcinoma, Transitional Cell; Female; Humans; Immunization; Lipid A; Lung Neoplasms; Male; Melanoma; Middle Aged; Neoplasm Metastasis; Neoplasm Proteins; Neoplasms; Recombinant Proteins; Saponins; Skin Neoplasms; Survival Analysis; Treatment Outcome; Urinary Bladder Neoplasms

An attenuated strain of Salmonella typhimurium, designated VNP20009, was generated by deletion of the msbB and purl genes. When VNP20009 was administered intravenously (IV) to mice bearing spontaneous, syngeneic, or human xenograft tumors, the bacteria accumulated preferentially within the extracellular components of tumors, forming tumor-to-normal tissue ratios exceeding 300-1000 to 1. NVP20009 was administered safely at doses up to 2.5 x 10(9) cfu/kg in monkey toxicology studies. Based on the preclinical data, VNP20009 entered Phase I human clinical trials in November 1999, and has now been administered to >45 patients by IV or direct intratumoral injection. By the intratumoral route, a maximum tolerated dose has not been reached, and dose escalation continues past the current dose level of 4 x 10(7)/m2. Furthermore, VNP20009 persisted in injected tumors for at least 2 weeks in 8/11 patients treated to date. By 30-min IV administration, a maximum tolerated dose (MTD) of 3 X 10(8) cfu/m2 has been established. In all patients treated to date, VNP20009 was not shed in urine or stool. VNP20009 has been further modified by chromosomal insertion of an E. coli cytosine deaminase (CD) gene at the deltamsbB locus which, when expressed, converts 5-fluorocytosine (5-FC) to 5-fluorouracil (5-FU). The CD containing VNP20009 was designated TAPET-CD or VNP20029. TAPET-CD had similar efficacy and safety in murine tumor models and similar safety profiles in animal toxicology studies, compared to its parent VNP20009. Specifically, TAPET-CD had a reduced virulence of >10,000 fold, when compared to the wild-type Salmonella strain. It was well-tolerated at doses up to 2 x 10(6) cfu/mouse and 1 X 10(10) cfu/monkey. After an IV or direct tumor injection to tumor-bearing mice, TAPET-CD reached tumor levels as high as 10(8)-10(9) cfu/gm. When compared to the accumulation in liver or spleen, the normal tissues with the greatest colonization of TAPET-CD, tumor-to-normal tissue ratios of TAPET-CD were 300-1000 to 1. TAPET-CD also caused tumor growth inhibition of >90% in several murine tumor models. When 5-FC was administered by intraperitoneal (IP) injection once or 3 times daily to tumor-bearing mice that had been pre-treated with TAPET-CD, high levels of 5-FU (reaching 20-40 microM/g) were detected in the tumor, with low or undetectable 5-FU levels in normal tissues (e.g., spleen, liver, etc.). Furthermore, co-administration of 5-FC and TAPET-CD in 4 different murine tumor mode

Topics: Acyltransferases; Antimetabolites; Antimetabolites, Antineoplastic; Combined Modality Therapy; Cytosine Deaminase; Dose-Response Relationship, Drug; Escherichia coli Proteins; Flucytosine; Fluorouracil; Gene Deletion; Gene Transfer Techniques; Humans; Lipid A; Maximum Tolerated Dose; Neoplasms; Nucleoside Deaminases; Salmonella typhimurium; Time Factors

ONO-4007 is a synthetic analogue of the lipid A moiety of bacterial lipopolysaccharide, which exhibits antitumor activity by the induction of intratumoral tumor necrosis factor alpha, the potentiation of tumor-infiltrating macrophages, and the inhibition of angiogenesis. Interleukin (IL)-1 alpha, IL-6, and IL-12 induction by ONO-4007 activates cytotoxic natural killer cells to up-regulate IFN-gamma and nitric oxide synthase activity. ONO-4007 was given to 24 patients (13 males and 11 females; median age, 53 years) as a 30-min i.v. infusion on day 1, followed on day 15 by a first treatment cycle consisting of three weekly infusions at the same dose, followed by a rest period of 1 week. Cohorts of six patients received up to a maximum of four treatment cycles at increasing dose levels (75, 100, and 125 mg). The maximum tolerated dose was 125 mg, with grade 3 National Cancer Institute Common Toxicity Criteria toxicity (rigors with cyanosis) occurring in two of six patients at this dose level. An additional six patients were treated at 100 mg, the dose below the maximum tolerated dose. Other toxicities included grade 2 National Cancer Institute Common Toxicity Criteria myalgia, nausea, and hypotension. The pharmacokinetics of ONO-4007 appeared to be independent of dose and showed linearity with respect to time. ONO-4007 has a low systemic clearance (approximately 1.3 ml/min) and a small volume of distribution (5-8 liters) with a long t1/2 of 74-95 h. The administration of ONO-4007 was shown to result in a significant increase in circulating levels of tumor necrosis factor alpha and IL-6. No objective antitumor responses were observed. Seven patients maintained stable disease for at least two cycles, whereas five patients maintained stable disease for the full four-cycle duration of the study. Additional studies are required to determine the antitumor activity of ONO-4007.

Topics: Adult; Aged; Antineoplastic Agents; Dose-Response Relationship, Drug; Female; Humans; Infusions, Intravenous; Lipid A; Male; Metabolic Clearance Rate; Middle Aged; Neoplasms; Tumor Necrosis Factor-alpha

Interfering with the endotoxin-mediated cytokine cascade is thought to be a promising approach to prevent septic complications in gram-negative infections. The synthetic lipid A analog SDZ MRL 953 has been shown to be protective against endotoxic shock and bacterial infection in preclinical in vivo models. As part of a trial of unspecific immunostimulation in cancer patients, we conducted a double-blind, randomized, vehicle-controlled phase I trial of SDZ MRL 953 to investigate, first, its biologic effects and safety of administration in humans and, second, its influence on reactions to a subsequent challenge of endotoxin (Salmonella abortus equi). Twenty patients were treated intravenously with escalating doses of SDZ MRL 953 or vehicle control, followed by an intravenous application of endotoxin (2 ng/kg of body weight [BW]). Administration of SDZ MRL 953 was safe and well-tolerated. SDZ MRL 953 itself increased granulocyte counts and serum levels of granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6), but not of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha), IL-1beta, and IL-8. Compared with vehicle control, pretreatment with SDZ MRL 953 markedly reduced the release of TNF-alpha, IL-1beta, IL-8, IL-6, and G-CSF, but augmented the increase in granulocyte counts to endotoxin. Induction of tolerance to the endotoxin-mediated cascade of proinflammatory cytokines by pretreatment with SDZ MRL 953 in patients at risk may help to prevent complications of gram-negative sepsis.

Topics: Adjuvants, Immunologic; Adolescent; Adult; Aged; Anti-Bacterial Agents; Bacterial Toxins; Cytokines; Double-Blind Method; Down-Regulation; Endotoxins; Humans; Interleukin-1; Interleukin-6; Interleukin-8; Lipid A; Lipopolysaccharides; Middle Aged; Neoplasms; Neutrophils; Prospective Studies; Salmonella; Tumor Necrosis Factor-alpha

Topics: Adjuvants, Immunologic; Clinical Trials as Topic; Humans; Immunity, Active; Immunotherapy; Leukocyte Count; Lipid A; Melanoma; Neoplasms; Oils; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Regulatory; Tumor Cells, Cultured; Vaccines

Gram-negative, facultatively anaerobic bacteria Salmonella Typhimurium is a candidate agent or delivery vector for cancer therapy. Effective targeted therapies in addition to radiotherapy, chemotherapy and surgery have been urgently needed as an alternative or supplement. This study expected to further improve the tumor-targeting ability of Salmonella bacteria through genetic modifications. Based on an auxotrophic Salmonella bacterial strain (D2), we constructed Salmonella mutants with altered LPS length to facilitate displaying the RGD4C targeting peptide on the outer membrane surface of Salmonella. The expression of RGD4C peptide in fusion with OmpA was identified by outer membrane protein extraction and WB detection in different mutant strains. However, flow cytometry analysis following immunofluorescence staining demonstrated that the extracellular length of Salmonella LPS did affect the surface display of RGD4C peptide. The strain D2-RGD4C that synthesized intact LPS including lipid A, core oligosaccharides and O antigen polysaccharides could hardly display RGD4C peptide, showing the same fluorescence signal intensity as the strains not expressing RGD4C peptide. Among different strains, D2 ∆rfaJ-RGD4C that synthesized truncated LPS including lipid A and partial core oligosaccharides was capable of displaying RGD4C peptide most efficiently and showed the highest ability to target HUVECs expressing αV integrin and tumor tissue with abundant neovascularization. Animal experiments also demonstrated that this tumor-targeting attenuated Salmonella strain to simultaneously deliver endostatin and TRAIL, two agents with different anti-tumor activities, could significantly inhibit tumor growth and prolong mouse survival. Thus, our studies revealed that Salmonella could be genetically engineered to improve its tumor targeting via the truncation of LPS and surface display of targeting peptides, thereby eliciting superior anti-tumor effects through targeted delivery of drug molecules.

Topics: Animals; Endostatins; Integrin alphaV; Lipid A; Lipopolysaccharides; Mice; Neoplasms; O Antigens; Peptides; Salmonella typhimurium

An efficient method was developed for the synthesis of a GM2 derivative suitable for the conjugation with various biomolecules. This GM2 derivative was covalently linked to keyhole limpet hemocyanin (KLH) and monophosphoryl lipid A (MPLA) to form novel therapeutic cancer vaccines. Immunological evaluations of the resultant conjugates in mice revealed that they elicited robust GM2-specific overall and IgG antibody responses. Moreover, the GM2-MPLA conjugate was disclosed to elicit strong immune responses without the use of an adjuvant, proving its self-adjuvant property. The antisera of both conjugates showed strong binding and mediated similarly effective complement-dependent cytotoxicity to GM2-expressing cancer cell line MCF-7. Based on these results, it was concluded that both GM2-MPLA and GM2-KLH are promising candidates as therapeutic cancer vaccines, whereas fully synthetic GM2-MPLA, which has homogeneous and well-defined structure and self-adjuvant property, deserves more attention and studies.

Topics: Adjuvants, Immunologic; Animals; Antibody-Dependent Cell Cytotoxicity; Cancer Vaccines; Complement System Proteins; Disease Models, Animal; Female; G(M2) Ganglioside; Lipid A; Mice; Molecular Structure; Neoplasms; Vaccines, Synthetic; Xenograft Model Antitumor Assays

This study reports on the design of mRNA and adjuvant-loaded lipid nanoparticles for therapeutic cancer vaccination. The use of nucleoside-modified mRNA has previously been shown to improve the translational capacity and safety of mRNA-therapeutics, as it prevents the induction of type I interferons (IFNs). However, type I IFNs were identified as the key molecules that trigger the activation of antigen presenting cells, and as such drive T cell immunity. We demonstrate that nucleoside-modified mRNA can be co-delivered with the clinically approved TLR agonist monophosphoryl lipid A (MPLA). As such, we simultaneously allow high antigen expression in vivo while substituting the type I IFN response by a more controllable adjuvant. This strategy shows promise to induce effective antigen-specific T cell immunity and may be useful to enhance the safety of mRNA vaccines.

Topics: Animals; Cancer Vaccines; Cytidine; Dendritic Cells; Female; Immunotherapy; Lipid A; Lipids; Mice, Inbred C57BL; Neoplasms; RNA, Messenger; Toll-Like Receptors

A semisynthetic strategy to obtain monophosphoryl lipid A derivatives equipped with clickable (azide, alkyne, double bond, or thiol precursor) moieties, starting from the native lipid A isolated from Escherichia coli, is presented. These lipid A derivatives can be conjugated with other interesting biomolecules, such as tumor-associated carbohydrate antigens (TACAs). In this way, the immunostimulant activity of monophosphoryl lipid A can significantly improve the immunogenicity of TACAs, thus opening access to potential self-adjuvant anticancer vaccine candidates. A monophosphoryl lipid A-Thomson-Friedenreich (TF) antigen conjugate was obtained to demonstrate the feasibility of this methodology, which stands as a valuable, rapid, and scalable alternative to the highly complex approaches of total synthesis recently reported to the same aim. A preliminary evaluation of the immunological activity of this conjugate as well as of other semisynthetic lipid A derivatives was also reported.

Topics: Adjuvants, Immunologic; Alkynes; Antigens, Tumor-Associated, Carbohydrate; Azides; Cancer Vaccines; Click Chemistry; Escherichia coli; Humans; Lipid A; Neoplasms; Sulfhydryl Compounds

Immune adjuvants are important components of current and prospective cancer vaccines. In this study, we aimed at evaluating the use of a synthetic lipid A derivative, pentaerythritol lipid A (PET lipid A), loaded into poly(lactic-co-glycolic acid) particles, as a potential cancer vaccine adjuvant. Poly(lactic-co-glycolic acid) particles (size range: 250-600 nm) were successfully formulated to include PET lipid A and/or the model tumor antigen, chicken ovalbumin (OVA). It was shown that particulated PET lipid A had a distinct advantage at promoting secretion of the immune potentiating cytokine, IL-12p70, and upregulating key costimulatory surface proteins, CD86 and CD40, in murine dendritic cells in vitro. In a murine tumor model, involving prophylactic vaccination with various permutations of soluble versus particulated formulations of OVA with or without PET lipid A, modest benefit was observed in terms of OVA-specific cell-mediated immune responses when PET lipid A was delivered in particles. These findings translated into a corresponding trend toward increased survival of mice challenged with OVA-expressing tumor cells (E.G7). In terms of translation of safe adjuvants into the clinic, these results promote the concept of delivering toll-like receptor-4 agonists in particles because doing so improves their adjuvant properties, while decreasing the chances of adverse effects due to off-target uptake by nonphagocytic cells.

Topics: Adjuvants, Immunologic; Animals; Antigens; Biocompatible Materials; Cancer Vaccines; Chemistry, Pharmaceutical; Cytokines; Dendritic Cells; Female; Lactic Acid; Lipid A; Mice; Mice, Inbred C57BL; Neoplasms; Ovalbumin; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Propylene Glycols; Toll-Like Receptors

Ex vivo-generated monocyte-derived dendritic cells (DCs) matured with monophosphoryl lipid A (MPLA) and interferon-γ (IFN-γ) can be used as cancer immunotherapy. MPLA/IFN-γ DCs induce Th1 T cell responses and have migratory capacity. Different culture regimens have been used for generation of immunotherapeutic DCs, with varying results. In the present study, culture conditions for MPLA/IFN-γ-matured type I DCs were optimized for clinical application.. DCs were generated from monocytes in the clinical grade culture media CellGro DC, AIM V or X-VIVO 15 in the absence or presence of 2% human serum (HS) and matured with the use of MPLA/IFN-γ. DC yield and DC functionality were assessed. DC functionality was determined by means of analysis of cytokines in culture supernatant, migratory capacity, expression of co-stimulatory molecules, T cell stimulatory capacity of DCs and T helper cell (Th) polarization by the DCs.. DCs generated in the presence of 2% HS produced low amounts of pro-inflammatory cytokines and could not migrate irrespective of the medium used. In the absence of HS, MPLA/IFN-γ DCs generated in X-VIVO did not migrate either. MPLA/IFN-γ DCs generated in AIM V have slightly lower capacity to induce Th1 cells than do DCs generated in CellGro or X-VIVO.. Addition of HS to different GMP culture media is detrimental for pro-inflammatory DC maturation and migration. In the absence of serum, CellGro is the most optimal medium tested for generation of migratory and Th1-inducing MPLA/IFN-γ DCs for cancer immunotherapy.

Topics: Cell Differentiation; Cell Proliferation; Cell- and Tissue-Based Therapy; Culture Media; Dendritic Cells; Humans; Immunotherapy; Interferon-gamma; Lipid A; Neoplasms; Th1 Cells

Monocyte-derived dendritic cells (DCs) used for immunotherapy e.g. against cancer are commonly matured by pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) and prostaglandin E(2) although the absence of Toll-like receptor mediated activation prevents secretion of IL-12 from DCs and subsequent efficient induction of type 1 effector T cells. Standard matured clinical grade DCs "sDCs" were compared with DCs matured with either of two type 1 polarizing maturation cocktails; the alpha-type-1 DCs "αDC1s" (TNF-α, IL-1β, IFN-γ, IFN-α, Poly(I:C)) and "mDCs" (monophosphoryl lipid A (MPL), IFN-γ) or a mixed cocktail - "mpDCs", containing MPL, IFN-γ and PGE(2). αDC1s and mDCs secreted IL-12 directly and following re-stimulation with CD40L-expressing cells and they mainly secreted the T effector cell attracting chemokines CXCL10 and CCL5 as opposed to sDCs that mainly secreted CCL22, known to attract regulatory T cells. αDC1s and mDCs were functionally superior to sDCs as they polarized naïve CD4(+) T cells most efficiently into T helper type 1 effector cells and primed more functional MART-1 specific CD8(+) T cells although with variation between donors. αDC1s and mDCs were transiently less capable of CCL21-directed transwell migration than standard matured DCs, likely due to their increased secretion of CCL19, which mediate internalization of CCR7. mpDCs were intermediate between standard and polarized DCs both in terms of IL-12 secretion and transwell migratory ability but functionally they resembled sDCs and strikingly had the highest expression of the inhibitory molecules PD-L1 and CD25. Thus, further studies with type 1 polarized DCs are warranted for use in immunotherapy, but when combined with PGE(2) as in mpDCs, they seems to be less optimal for maturation of DCs.

Topics: Cancer Vaccines; Cell Differentiation; Cell Line; Cell Movement; Cytokines; Dendritic Cells; Humans; Immunotherapy; Interferon-gamma; Lipid A; Neoplasms; Th1 Cells

Tumor-associated carbohydrate antigens (TACAs) are useful targets in the development of therapeutic cancer vaccines. However, a serious problem with them is the poor immunogenicity. To overcome the problem, a monophosphorylated derivative of Neisseria meningitidis lipid A was explored as a potential carrier molecule and built-in adjuvant for the construction of structurally defined fully synthetic glycoconjugate vaccines. Some paradigm-shifting discoveries about the monophosphoryl lipid A (MPLA)-TACA conjugates were that they elicited robust IgG antibody responses, indicating T cell-mediated immunity, without an external adjuvant and that an external adjuvant, e.g., Titermax Gold, actually reduced rather than promoted the immunological activity of the conjugates. The induced antibodies were proved to bind selectively to target tumor cells. MPLA was therefore demonstrated to be a powerful built-in immunostimulant and adjuvant for an all new design of fully synthetic glycoconjugate cancer vaccines.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Neoplasm; Antigens, Tumor-Associated, Carbohydrate; Cancer Vaccines; Cell Line, Tumor; G(M3) Ganglioside; Glycoconjugates; Immunity, Cellular; Immunoglobulin G; Lipid A; Mice; Mice, Inbred C57BL; Molecular Structure; Neisseria meningitidis; Neoplasms; Vaccination; Vaccines, Synthetic

Topics: Animals; Humans; Immunotherapy; Lipid A; Mice; Neoplasms

The lipid A analogs used in preclinical studies and clinical trials are not naturally-occurring forms of lipid A; they are synthetic molecules produced to be less toxic than lipid A itself and they do not reproduce the effects of natural lipid A molecules especially in vivo. The responses induced by lipid A analogs are summarized in this chapter: their fate in the blood stream and their toxicity as well as the lipid A tolerance and the tumor immune responses they induce. Lipid A is not found in the mammalian organism under normal circumstances so its use in cancer therapy raises important questions as to its different effects in vivo and its toxicity, particularly in cancer patients. Lipid A has to be injected intravenously (i.v.) to study its effects. Injections of chemically synthesized lipid A in humans and in animals produce sepsis symptoms, such as tachycardia, tachypnea, hyper or hypothermia and leukocytosis or leukopenia. Similar manifestations are observed after injection of purified lipopolysaccharide (LPS), which is why lipid A is usually thought of as the active part of LPS. While lipid A injection is therefore expected to induce reactions similar to septic shock, the lipid A molecules used to treat cancer are not natural forms but analogs, produced by chemical synthesis or genetic engineering, specifically selected for their low toxicity. The in vivo effects of such low-toxicity lipid A analogs are summarized in this chapter.

Topics: Animals; Humans; Immunity, Cellular; Lipid A; Neoplasms

Studies in animal models showed that the antitumoral effect of LPS and of their biologically active moiety, lipid A, is indirect and relies on the induction of an immune response both innate and specific, leading to cytokine production. They also affect tumor development by inhibiting tumor blood flow and induce necrosis as well as apoptosis of tumor cells. Lipids A have been tested in animals, either alone or as adjuvant in therapeutic vaccines. The efficacy of treatments depends on the type of molecule and on the protocol. In general, increased survival was obtained, accompanied in some cases by tumor regression and cure.

Topics: Animals; Apoptosis; Humans; Lipid A; Neoplasms

The term "tolerance" from an immunological perspective, broadly encompasses a number of phenomena, but generally refers to a diminished responsiveness to LPS and/or other microbial products. With the discovery that many of the immunological, physiological and/or pathophysiological effects of LPS can be attributed to the lipid A moiety of the LPS molecule, a number of different lipid A analogs were synthesized with the goal of developing a drug that could be used clinically to treat cancer. In many instances, the development of tolerance to the lipid A congeners confounded the utility of these analogs as cancer therapeutics. In certain circumstances, however, the development of tolerance in patients has been utilized therapeutically to protect immunosuppressed patients from sepsis. Although numerous studies have been designed to investigate the development of tolerance, the underlying molecular mechanism remains unclear. This may be due, in part, to differences in the experimental models used, the sources and types of microbes and microbial products studied, kinetics of responses, and/or other experimental conditions. Nonetheless, a number of different signaling pathways have been identified as potentially modulating and/or triggering the development of tolerance. Though complex and incompletely understood, the capacity of tolerance to impact lipid A-based therapeutics, either positively or negatively, is inarguable, thus underscoring the necessity for further investigation toward elucidating the mechanisms contributing to the development of tolerance to lipid A and its analogs.

Topics: Animals; Humans; Lipid A; Neoplasms; Signal Transduction

Cancer remains the second leading cause of death, after cardiovascular diseases, in industrialized countries. The first goal to achieve is to prevent cancer occurrence or to diagnose it at an early and curable stage. Some screening strategies have been developed, with controversies across countries, for several cancer type; colorectal, breasts or prostate cancer for example.Treatment of cancer is generally based on surgery and radiotherapy for localized and attainable tumors, associated, in some cases, with adjuvant chemotherapy. Chemotherapy can also be used as first line treatment for disseminated diseases.The formulation of therapeutic strategies to enhance immune-mediated tumor destruction is a central goal of cancer immunology. Substantive progress toward delineating the mechanisms involved in innate and adaptive tumor immunity has improved the prospects for crafting efficacious treatments LPS and their active component lipid A, have been used in tumor therapy since the 19th century.Studies in animal models have shown promising results on different models of cancer but data from human trial are scarce. The published Phase-1 cancer studies have shown that lipid A analogues are usually well tolerated, most of the side effects being likely related to immune response, i. e., fever, chills and rigor. The administration of several lipids A analogues was shown to result in a significant increase in circulating levels of several cytokines but no objective antitumor responses were observed. Therefore clinical activity of such molecules deserves further experiments, likely in conjunction with chemotherapy.

Topics: Animals; Humans; Lipid A; Neoplasms

Topics: Humans; Lipid A; Neoplasms

For injectable-sized liposome complexed with DNA (lipoplexes) with high transfection efficiency of genes, we initially prepared small-sized liposomes by addition of biosurfactant. For selectivity of gene expression, the thymidine kinase (MK-tk) gene controlled by midkine was used for herpes simplex virus thymidine kinase (HSV-tk) gene therapy. Liposomes composed of 3([N-(N',N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol), L-dioleoylphosphatidylethanolamine (DOPE), and a biosurfactant, such as beta-sitosterol beta-D-glucoside (Sit-G) for Sit-G-liposomes and mannosylerythrytol lipid A (MEL) for MEL-liposomes, produced about 300-nm-sized lipoplexes. Sit-G- and MEL-liposomes showed higher transfection efficiency of the luciferase marker gene and thymidine kinase activity in the presence of serum in the cells. The treatment with transfection of MK-tk gene by Sit-G-liposome and injection of ganciclovir significantly reduced tumor growth in a solid tumor model, compared with that by Sit-G-liposome alone. This finding suggested that Sit-G-liposome is a potential vector for HSV-tk gene therapy.

Topics: Animals; Cell Line, Tumor; Cell Survival; DNA, Viral; Female; Gene Expression; Genetic Therapy; Genetic Vectors; Humans; Lipid A; Liposomes; Mannose; Mice; Mice, Inbred BALB C; Mice, Nude; Molecular Structure; Neoplasms; Particle Size; Simplexvirus; Surface-Active Agents; Thymidine Kinase; Transfection; Xenograft Model Antitumor Assays

Topics: Animals; Bacterial Infections; Humans; Inflammation; Lipid A; Lipopolysaccharides; Mice; Neoplasms; Salmonella typhimurium; Vaccines, Attenuated

In this study, limited sampling models for HA-1A human IgM monoclonal antibody were developed to predict the area under the concentration time curve from timed serum concentrations. Patients were administered 15 minute infusions of 25 mg (11 patients), 100 mg (15 patients), and 250 mg (2 patients). A detailed pharmacokinetic analysis (eight time points) was performed to obtain the area under the curve for each of the 28 patients using a one-compartment model with the values normalized to a dose of 100 mg. Various models were then developed to estimate the area under the curve from one and two timed concentrations using regression analysis methodology. Of these models, four were determined to be of interest with coefficients of determinations ranging from 0.92 to 0.97. They performed quite well in predicting the area under the curve values with relative root mean squared predictive error of 7.1 to 10.8% and relative mean predictive error of -4.5 to + 6.9%. These models should be extremely useful in larger scale, Phase II/III studies of HA-1A in correlating the estimated area under the curve with various demographic data, toxicity, and efficacy.

Topics: Antibodies, Monoclonal; Bacterial Infections; Body Fluid Compartments; Gram-Negative Bacteria; Humans; Immunoglobulin M; Lipid A; Models, Theoretical; Neoplasms

A human monoclonal antibody (HA-1A) directed against bacterial endotoxin was administered to 15 patients with incurable malignant disease. No adverse effects were noted following single intravenous infusions of 0.05 to 100 mg. Pharmacokinetics were evaluated in nine patients receiving 10 mg (n = 3), 25 mg (n = 3), and 100 mg (n = 3). Seven of these patients had initial peak serum concentrations greater than 80% of predicted values with plasma disappearance curves fitting a one-compartment system and a plasma half-life of 31.5 h (range of 20.3-44.6 h). The peak serum concentrations and area under the curve values were proportional to the dose of HA-1A administered. One patient had a hypercatabolic state with low levels of serum albumin and IgM. He achieved 65% of the predicted value for peak serum concentration of HA-1A with a plasma half-life of 12.3 h. A second patient had detectable serum HA-1A for only 15 min following infusion without an adequate technical or biologic explanation. We were unable to demonstrate antibody to HA-1A in sera from these nine patients either prior to therapy or during 28 days postinfusion using a "double-antigen" radiometric assay. This study suggests that HA-1A human monoclonal antibody administration is well tolerated by patients. Phase I trials will need to be carried out to characterize further the pharmacokinetics and toxicity of HA-1A in patients with gram-negative sepsis.

Topics: Adult; Antibodies, Monoclonal; Endotoxins; Female; Half-Life; Humans; Immunoglobulin M; Lipid A; Male; Middle Aged; Neoplasms

The clinical toxicity of acetic acid-treated "Salmonella minnesota" R595 (Re) organisms was evaluated in 24 cancer patients. Bacteria were injected i.v. four times at increasing doses for a total of 6.5 micrograms. This therapeutic regimen was free of major side effects (one patient had fever higher than 38 degrees C and 10 patients complained of pruritus). Furthermore, this bacterial preparation which possesses a more exposed lipid A on its surface, exhibited immunomodulating capacities in that it normalized the inverted T helper/T suppressor ratio and enhanced natural killer activity in tumor patients. The mechanisms of the lower toxicity and immunomodulating activities of these bacteria compared to other lipid A preparations are discussed.

Topics: Acetates; Acetic Acid; Adult; Aged; Aged, 80 and over; Female; Humans; Immunotherapy; Killer Cells, Natural; Leukocyte Count; Lipid A; Male; Middle Aged; Neoplasms; Salmonella; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory

Endotoxin and the lipid-A portion of the molecule have a variety of biological effects, including the induction of necrosis and regression of malignancy. To date extensive clinical trials of endotoxin as a potential therapeutic agent have been shunned due to the toxicity of the material. Several lipid-A analogues have been described which have reduced toxicity and retain antitumor activity. We have investigated in a phase-I trial the clinical toxicity and immunological effects of monophosphoryl lipid A prepared from Salmonella typhimurium and Salmonella minnesota. Patients entered on the study received IV monophosphoryl lipid A twice weekly for a total of 4 weeks. At least three patients were entered sequentially at each of the dose levels of 10, 25, 50, 100, and 250 micrograms/m2 body surface area. One patient was treated at the dose level of 500 micrograms/m2. The major clinical toxicity was fever, chills, and rigor, which occurred in over 50% of the treatments at doses of 250 micrograms/m2. Two instances of bronchospasm occurred in one patient who received 250 micrograms/m2. One patient received 500 micrograms/m2 and became hypotensive. Sequential clinical data showed no evidence of renal or hepatic toxicity. A transient decrease in the WBC and platelets occurred during the first 24 h after therapy. Immune function testing measured T cells, monocyte cytostasis, monocyte suppressor cell activity, and NK activity. These data suggested a shift in monocyte populations with activated cells moving into the tissue. Direct objective antitumor activity or necrosis was not observed in this group of patients. We conclude that monophosphoryl lipid A can be given to patients in a dose of up to 100 micrograms/m2 with acceptable toxicity. Its clinical activity as a single agent in combination with other immunomodulators remains to be demonstrated.

Topics: Animals; Drug Evaluation; Immunotherapy; Injections, Intravenous; Lipid A; Neoplasms; Salmonella; Salmonella typhimurium; Skin Tests

Topics: Animals; Antibody Formation; Antibody-Producing Cells; Blood Coagulation; Cardiovascular System; Complement System Proteins; Endotoxins; Graft vs Host Reaction; Hematopoietic System; Humans; Immunosuppression Therapy; Infection Control; Interferons; Lipid A; Lipopolysaccharides; Lymphocytes; Macrophages; Neoplasms; Polysaccharides, Bacterial

Topics: Antineoplastic Agents; Humans; Lipid A; Lipids; Neoplasms

Topics: Antineoplastic Agents; Humans; Lipid A; Lipids; Neoplasms