lipid-a and 6-6--dicorynomycolyl-trehalose

The aim of this study was to evaluate, in terms of dog macrophage killing ability in vitro, a vaccine based on Leishmania infantum promastigote soluble antigen (LSA) formulated with three different adjuvants (BCG, AdjuPrime, MPL/TDM/CWS). A significant increase of the macrophage killing ability was observed in dogs vaccinated with LSA+MPL/TDM/CWS after 1 month from vaccination. A similar increase of macrophage parasitocidal ability was present only after 5 months in dogs vaccinated with LSA+BCG or LSA+AdjuPrime. In all dogs the augmented killing percentage was still present after 12 months from vaccination. Therefore, in particular LSA+MPL/TDM/CWS vaccine seems promising for further studies in dogs.

Topics: Adjuvants, Immunologic; Animals; Antigens, Protozoan; BCG Vaccine; Cell Wall Skeleton; Cord Factors; Dog Diseases; Dogs; Female; Humans; Leishmania infantum; Leishmaniasis; Leishmaniasis Vaccines; Leukocytes, Mononuclear; Lipid A; Macrophages; Male; Time Factors

Metastatic cancer involving spread to the peritoneal cavity is referred to as peritoneal carcinomatosis and has a very poor prognosis. Activating the antitumor immune response in the characteristically immune-suppressive peritoneal environment presents a potential strategy to treat this disease. In this study, we show that a toll-like receptor (TLR) and C-type lectin receptor (CLR) agonist pairing of monophosphoryl lipid A (MPL) and trehalose-6,6'-dicorynomycolate (TDCM) effectively inhibits tumor growth and ascites development in a mouse model of aggressive mammary cancer-induced peritoneal carcinomatosis. MPL/TDCM treatment similarly inhibited peritoneal EL4 tumor growth and ascites development. These effects were not observed in mice lacking B cells or mice lacking CD19, which are deficient in B-1a cells, an innate-like B-cell population enriched in the peritoneal cavity. Remarkably, adoptive transfer of B-1a cells, but not splenic B cells from WT mice, restored MPL/TDCM-induced protection in mice with B-cell defects. Treatment induced B-1 cells to rapidly produce high levels of natural IgM reactive against tumor-associated carbohydrate antigens. Consistent with this, we found significant deposition of IgM and C3 on peritoneal tumor cells as early as 5 days post-treatment. Mice unable to secrete IgM or complement component C4 were not protected by MPL/TDCM treatment, indicating tumor killing was mediated by activation of the classical complement pathway. Collectively, our findings reveal an unsuspected role for B-1 cell-produced natural IgM in providing protection against tumor growth in the peritoneal cavity, thereby highlighting potential opportunities to develop novel therapeutic strategies for the prevention and treatment of peritoneal metastases. SIGNIFICANCE: This work identifies a critical antitumor role for innate-like B cells localized within the peritoneal cavity and demonstrates a novel strategy to activate their tumor-killing potential.

Topics: Animals; B-Lymphocyte Subsets; Cord Factors; Female; Immunity, Innate; Immunoglobulin M; Lectins, C-Type; Lipid A; Lymphocyte Activation; Male; Mammary Neoplasms, Animal; Mice; Mice, Inbred A; Mice, Inbred C57BL; Peritoneal Cavity; Peritoneal Neoplasms; Toll-Like Receptors

A combination therapy for combined injury (CI) using a non-specific immunomodulator, synthetic trehalose dicorynomycolate and monophosphoryl lipid A (STDCM-MPL), was evaluated to augment oral antimicrobial agents, levofloxacin (LVX) and amoxicillin (AMX), to eliminate endogenous sepsis and modulate cytokine production.. Female B6D2F(1)/J mice received 9.75 Gy cobalt-60 gamma-radiation and wound. Bacteria were isolated and identified in three tissues. Incidence of bacteria and cytokines were compared between treatment groups.. Results demonstrated that the lethal dose for 50% at 30 days (LD(50/30)) of B6D2F(1)/J mice was 9.42 Gy. Antimicrobial therapy increased survival in radiation-injured (RI) mice. Combination therapy increased survival after RI and extended survival time but did not increase survival after CI. Sepsis began five days earlier in CI mice than RI mice with Gram-negative species predominating early and Gram-positive species increasing later. LVX plus AMX eliminated sepsis in CI and RI mice. STDCM-MPL eliminated Gram-positive bacteria in CI and most RI mice but not Gram-negative. Treatments significantly modulated 12 cytokines tested, which pertain to wound healing or elimination of infection.. Combination therapy eliminates infection and prolongs survival time but does not assure CI mouse survival, suggesting that additional treatment for proliferative-cell recovery is required.

Topics: Amoxicillin; Animals; Anti-Infective Agents; Bacterial Infections; Chemokines; Cord Factors; Cytokines; Disease Models, Animal; Drug Therapy, Combination; Female; Gamma Rays; Growth Substances; Immunologic Factors; Levofloxacin; Lipid A; Mice; Radiation Injuries, Experimental; Sepsis; Skin; Wound Infection

With the paucity of new drugs and HIV co-infection, vaccination remains an unmet research priority to combat visceral leishmaniasis (VL) requiring strong cellular immunity. Protein vaccination often suffers from low immunogenicity and poor generation of memory T cells for long-lasting protection. Cysteine proteases (CPs) are immunogenic proteins and key mediators of cellular functions in Leishmania. Here, we evaluated the vaccine efficacies of CPs against VL, using cationic liposomes with Toll like receptor agonists for stimulating host immunity against L. donovani in a hamster model.. Recombinant CPs type I (cpb), II (cpa) and III (cpc) of L. donovani were tested singly and in combination as a triple antigen cocktail for antileishmanial vaccination in hamsters. We found the antigens to be highly immunoreactive and persistent anti-CPA, anti-CPB and anti-CPC antibodies were detected in VL patients even after cure. The liposome-entrapped CPs with monophosphoryl lipid A-Trehalose dicorynomycolate (MPL-TDM) induced significantly high nitric oxide (up to 4 fold higher than controls) mediated antileishmanial activity in vitro, and resulted in strong in vivo protection. Among the three CPs, CPC emerged as the most potent vaccine candidate in combating the disease. Interestingly, a synergistic increase in protection was observed with liposomal CPA, CPB and CPC antigenic cocktail which reduced the organ parasite burden by 1013-1016 folds, and increased the disease-free survival of >80% animals at least up to 6 months post infection. Robust secretion of IFN-γ and IL-12, along with concomitant downregulation of Th2 cytokines, was observed in cocktail vaccinates, even after 3 months post infection.. The present study is the first report of a comparative efficacy of leishmanial CPs and their cocktail using liposomal formulation with MPL-TDM against L. donovani. The level of protection attained has not been reported for any other subcutaneous single or polyprotein vaccination against VL.

Topics: Animals; Antigens, Protozoan; Cations; Cord Factors; Cricetinae; Cysteine Proteases; Disease Models, Animal; Drug Delivery Systems; Leishmania donovani; Leishmaniasis; Lipid A; Liposomes; Mesocricetus; Protozoan Vaccines

The development of a long-term protective subunit vaccine against visceral leishmaniasis depends on antigens and adjuvants that can induce an appropriate immune response. The immunization of leishmanial antigens alone shows limited efficacy in the absence of an appropriate adjuvant. Earlier we demonstrated sustained protection against Leishmania donovani with leishmanial antigens entrapped in cationic liposomes through an intraperitoneal route. However, this route is not applicable for human administration. Herein, we therefore evaluated the immune response and protection induced by liposomal soluble leishmanial antigen (SLA) formulated with monophosphoryl lipid-trehalose dicorynomycolate (MPL-TDM) through a subcutaneous route. Subcutaneous immunization of BALB/c mice with SLA entrapped in liposomes or with MPL-TDM elicited partial protection against experimental visceral leishmaniasis. In contrast, liposomal SLA adjuvanted with MPL-TDM induced significantly higher levels of protection in liver and spleen in BALB/c mice challenged 10 days post-vaccination. Protection conferred by this formulation was sustained up to 12 weeks of immunization, and infection was controlled for at least 4 months of the challenge, similar to liposomal SLA immunization administered intraperitoneally. An analysis of cellular immune responses of liposomal SLA + MPL-TDM immunized mice demonstrated the induction of IFN-γ and IgG2a antibody production not only 10 days or 12 weeks post-vaccination but also 4 months after the challenge infection and a down regulation of IL-4 production after infection. Moreover, long-term immunity elicited by this formulation was associated with IFN-γ production also by CD8⁺ T cells. Taken together, our results suggest that liposomal SLA + MPL-TDM represent a good vaccine formulation for the induction of durable protection against L. donovani through a human administrable route.

Topics: Adjuvants, Immunologic; Animals; Antigens, Protozoan; Cells, Cultured; Chemical Phenomena; Cord Factors; Immunity, Active; Immunity, Cellular; Immunologic Memory; Injections, Subcutaneous; Interferon-gamma; Interleukin-4; Leishmania donovani; Leishmaniasis Vaccines; Leishmaniasis, Visceral; Lipid A; Liposomes; Liver; Mice; Mice, Inbred BALB C; Phospholipids; Specific Pathogen-Free Organisms; Spleen

Vaccines that activate strong specific Th1-predominant immune responses are critically needed for many intracellular pathogens, including Leishmania. The requirement for sustained and efficient vaccination against leishmaniasis is to formulate the best combination of immunopotentiating adjuvant with the stable antigen (Ag) delivery system. The aim of the present study is to evaluate the effectiveness of an immunomodulator on liposomal Ag through subcutaneous (s.c.) route of immunization, and its usefulness during prime/boost against visceral leishmaniasis (VL) in BALB/c mice.. Towards this goal, we formulated recombinant GP63 (rGP63)-based vaccines either with monophosphoryl lipid A-trehalose dicorynomycolate (MPL-TDM) or entrapped within cationic liposomes or both. Combinatorial administration of liposomes with MPL-TDM during prime confers activation of dendritic cells, and induces an early robust T cell response. To investigate whether the combined formulation is required for optimum immune response during boost as well, we chose to evaluate the vaccine efficacy in mice primed with combined adjuvant system followed by boosting with either rGP63 alone, in association with MPL-TDM, liposomes or both. We provide evidences that the presence of either liposomal rGP63 or combined formulations during boost is necessary for effective Th1 immune responses (IFN-γ, IL-12, NO) before challenge infection. However, boosting with MPL-TDM in conjugation with liposomal rGP63 resulted in a greater number of IFN-γ producing effector T cells, significantly higher levels of splenocyte proliferation, and Th1 responses compared to mice boosted with liposomal rGP63, after virulent Leishmania donovani (L. donovani) challenge. Moreover, combined formulations offered superior protection against intracellular amastigote replication in macrophages in vitro, and hepatic and splenic parasite load in vivo.. Our results define the immunopotentiating effect of MPL-TDM on protein Ag encapsulated in a controlled release system against experimental VL.

Topics: Adjuvants, Immunologic; Animals; Cord Factors; Cytokines; Disease Models, Animal; Female; Humans; Injections, Subcutaneous; Leishmania donovani; Leishmaniasis Vaccines; Leishmaniasis, Visceral; Lipid A; Liposomes; Metalloendopeptidases; Mice; Mice, Inbred BALB C; Nitric Oxide; Phosphatidylcholines; Th1 Cells; Vaccination; Vaccines, Synthetic

The development of an effective vaccine against visceral leishmaniasis (VL) caused by Leishmania donovani is an essential aim for controlling the disease. Use of the right adjuvant is of fundamental importance in vaccine formulations for generation of effective cell-mediated immune response. Earlier we reported the protective efficacy of cationic liposome-associated L. donovani promastigote antigens (LAg) against experimental VL. The aim of the present study was to compare the effectiveness of two very promising adjuvants, Bacille Calmette-Guerin (BCG) and Monophosphoryl lipid A (MPL) plus trehalose dicorynomycolate (TDM) with cationic liposomes, in combination with LAg, to confer protection against murine VL.. All the three formulations afforded significant protection against L. donovani in both the visceral organs, liver and spleen. Although comparable level of protection was observed in BCG+LAg and MPL-TDM+LAg immunized mice, highest level of protection was exhibited by the liposomal LAg immunized group. Significant increase in anti-LAg IgG levels were detected in both MPL-TDM+LAg and liposomal LAg immunized animals with higher levels of IgG2a than IgG1. But BCG+LAg failed to induce any antibody response. As an index of cell-mediated immunity DTH responses were measured and significant response was observed in mice vaccinated with all the three different formulations. However, highest responses were observed with liposomal vaccine immunization. Comparative evaluation of IFN-gamma and IL-4 responses in immunized mice revealed that MPL-TDM+LAg group produced the highest level of IFN-gamma but lowest IL-4 level, while BCG+LAg demonstrated generation of suboptimum levels of both IFN-gamma and IL-4 response. Elicitation of moderate levels of prechallenge IFN-gamma along with optimum IL-4 corresponds with successful vaccination with liposomal LAg.. This comparative study reveals greater effectiveness of the liposomal vaccine for protection against progressive VL in BALB/c. Again, evaluation of the immune responses by vaccination emphasizes the need of stimulation of potent cellular immunity based on both Th1 and Th2 cell responses to confer protection against VL.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Protozoan; Antigens, Protozoan; BCG Vaccine; Cord Factors; Female; Immunity, Humoral; Leishmaniasis Vaccines; Leishmaniasis, Visceral; Lipid A; Mice; Time Factors

The potential threat of smallpox use in a bioterrorist attack has heightened the need to develop an effective smallpox vaccine for immunization of the general public. Vaccination with the current smallpox vaccine, Dryvax, produces protective immunity but may result in adverse reactions for some vaccinees. A subunit vaccine composed of protective vaccinia virus proteins should avoid the complications arising from live-virus vaccination and thus provide a safer alternative smallpox vaccine. In this study, we assessed the protective efficacy and immunogenicity of a multisubunit vaccine composed of the A27L and D8L proteins from the intracellular mature virus (IMV) form and the B5R protein from the extracellular enveloped virus (EEV) form of vaccinia virus. BALB/c mice were immunized with Escherichia coli-produced A27L, D8L, and B5R proteins in an adjuvant consisting of monophosphoryl lipid A and trehalose dicorynomycolate or in TiterMax Gold adjuvant. Following immunization, mice were either sacrificed for analysis of immune responses or lethally challenged by intranasal inoculation with vaccinia virus strain Western Reserve. We observed that three immunizations either with A27L, D8L, and B5R or with the A27L and B5R proteins alone induced potent neutralizing antibody responses and provided complete protection against lethal vaccinia virus challenge. Several linear B-cell epitopes within the three proteins were recognized by sera from the immunized mice. In addition, protein-specific cellular responses were detected in spleens of immunized mice by a gamma interferon enzyme-linked immunospot assay using peptides derived from each protein. Our data suggest that a subunit vaccine incorporating bacterially expressed IMV- and EEV-specific proteins can be effective in stimulating anti-vaccinia virus immune responses and providing protection against lethal virus challenge.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Viral; Cord Factors; Epitopes, B-Lymphocyte; Escherichia coli; Female; Humans; Interferon-gamma; Lipid A; Lymphocytes; Membrane Glycoproteins; Membrane Proteins; Mice; Mice, Inbred BALB C; Neutralization Tests; Poloxalene; Smallpox; Smallpox Vaccine; Spleen; Survival Analysis; Vaccines, Subunit; Vaccinia virus; Viral Envelope Proteins; Viral Proteins; Viral Structural Proteins

Complete Freund's adjuvant (CFA) is effective for potentiating immune responses in mice when administered subcutaneously, and is often more potent when given intraperitoneally (i.p.). However, the the potential toxicity of i.p. administration in mice has led investigators and Institutional Animal Care and Use committees to increasingly view the use of CFA i.p. with reservation. We evaluated whether an 80% reduction in the dose of CFA administered i.p. to mice, compared to the i.p. doses used in a previous analysis, could abrogate the untoward effects associated with its use, while still maintaining adjuvanticity. Using a novel immunogen targeting the N-terminus of the 42-amino acid amyloid-beta peptide, we compared low dose CFA administered i.p., with three other commonly used adjuvants given i.p.: alum, incomplete Freunds adjuvant (IFA) and monophoshoryl lipid A + trehalose dicorynomycolate (MPL + TDM). The results of the study showed that, though the reduction in intraperitoneal dose of CFA mitigated transient weight loss and leukocytosis observed previously with higher doses of i.p. CFA, all mice administered CFA or IFA i.p. developed abdominal adhesions and granulomatous peritonitis. Mice from all adjuvant groups, however, appeared to tolerate the respective adjuvants well and excellent comparative immunogenicity was observed in mice immunized with the Freunds and MPL + TDM adjuvants. Consequently, we conclude that though a high-titered, humoral response may be generated using low dose CFA administered i.p., the accompanying toxicity remains significant, and thus alternative adjuvants and/or routes should be considered.

Topics: Adjuvants, Immunologic; Alum Compounds; Alzheimer Vaccines; Amyloid beta-Peptides; Animals; Antibodies; Body Weight; Cord Factors; Female; Freund's Adjuvant; Injections, Intraperitoneal; Leukocyte Count; Lipid A; Mice; Mice, Inbred C57BL; Models, Animal; Spleen

Mice were injected three times at 2 week intervals with the adjuvant MPL + TDM or phosphate-buffered saline. Two weeks after the last injection, all mice were challenged subcutaneously with a tumorgenic dose of B16 tumor and observed for 40 days. The adjuvant hastened the time at which tumors appeared (P = 0.02).

Topics: Adjuvants, Immunologic; Animals; Cord Factors; Lipid A; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Tumor Cells, Cultured