ovalbumin and Haemophilus-Infections

The anti-inflammatory properties associated with intravenous immunoglobulin therapy require the sialic acid modification of the N-glycan of the Fc domain of IgG. Sialylation of the Fc fragment is mediated by β-galactoside α2,6-sialyltransferase 1 (ST6Gal-1), acting on the Gal(β4)GlcNAc terminal structure of the biantennary N-glycans on the Fc domain. However, little is known regarding the in vivo regulation of Fc sialylation and its role in the progression of inflammatory processes. Here, we report that decreased Fc sialylation of circulatory IgG accompanies the acute phase response elicited by turpentine exposure or upon acute exposure to either nontypeable Haemophilus influenzae or ovalbumin. However, Fc sialylation was increased 3-fold from the base line upon transition to chronic inflammation by repeated exposure to challenge. The P1 promoter of the ST6Gal-1 gene is critical for Fc sialylation, but P1 does not drive ST6Gal-1 expression in B cells. The Siat1ΔP1 mouse, with a dysfunctional P1 promoter, was unable to produce sialylated Fc in the systemic circulation, despite the presence of Gal(β4)GlcNAc termini on the Fc glycans. The major contribution of P1 action is to synthesize ST6Gal-1 enzymes that are deposited into the systemic circulation. The data strongly indicate that this pool of extracellular ST6Gal-1 in the blood impacts the sialylation of IgG Fc and that defective Fc sialylation is likely a major contributing mechanism for the proinflammatory tendencies previously noted in Siat1ΔP1 animals.

Topics: Acute-Phase Reaction; Animals; Anti-Inflammatory Agents; beta-D-Galactoside alpha 2-6-Sialyltransferase; Blotting, Western; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Haemophilus Infections; Haemophilus influenzae; Immunoglobulin Fc Fragments; Immunoglobulin G; Mice; Mice, Inbred C57BL; Mice, Knockout; N-Acetylneuraminic Acid; Ovalbumin; Pneumonia; Polysaccharides; Promoter Regions, Genetic; Sialyltransferases; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Turpentine

Several epidemiologic studies have found that smokers with chronic obstructive pulmonary disease (COPD), an inflammatory disease of the lung, have an increased risk of lung cancer compared with smokers without COPD. We have shown a causal role for COPD-like airway inflammation in lung cancer promotion in the CCSP(Cre)/LSL-K-ras(G12D) mouse model (CC-LR). In contrast, existing epidemiologic data do not suggest any definite association between allergic airway inflammation and lung cancer. To test this, CC-LR mice were sensitized to ovalbumin (OVA) and then challenged with an OVA aerosol weekly for 8 weeks. This resulted in eosinophilic lung inflammation associated with increased levels of T helper 2 cytokines and mucous metaplasia of airway epithelium, similar to what is seen in asthmatic patients. However, this type of inflammation did not result in a significant difference in lung surface tumor number (49 ± 9 in OVA vs. 52 ± 5 in control) in contrast to a 3.2-fold increase with COPD-like inflammation. Gene expression analysis of nontypeable Haemophilus influenzae (NTHi)-treated lungs showed upregulation of a different profile of inflammatory genes, including interleukin 6 (IL-6), compared with OVA-treated lungs. Therefore, to determine the causal role of cytokines that mediate COPD-like inflammation in lung carcinogenesis, we genetically ablated IL-6 in CC-LR mice. This not only inhibited intrinsic lung cancer development (1.7-fold) but also inhibited the promoting effect of extrinsic COPD-like airway inflammation (2.6-fold). We conclude that there is a clear specificity for the nature of inflammation in lung cancer promotion, and IL-6 has an essential role in lung cancer promotion.

Topics: Aerosols; Animals; Biomarkers, Tumor; Cytokines; Disease Models, Animal; Female; Gene Expression Profiling; Haemophilus Infections; Haemophilus influenzae; Immunoenzyme Techniques; Integrases; Interleukin-6; Lung Neoplasms; Mice; Mice, Inbred C57BL; Mice, Knockout; Mutation; Oligonucleotide Array Sequence Analysis; Ovalbumin; Pneumonia; Proto-Oncogene Proteins p21(ras); Pulmonary Disease, Chronic Obstructive; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Survival Rate; Th2 Cells; Tumor Burden; Uteroglobin

A subset of patients with stable asthma has prominent neutrophilic and reduced eosinophilic inflammation, which is associated with attenuated airways hyper-responsiveness (AHR). Haemophilus influenzae has been isolated from the airways of neutrophilic asthmatics; however, the nature of the association between infection and the development of neutrophilic asthma is not understood. Our aim was to investigate the effects of H. influenzae respiratory infection on the development of hallmark features of asthma in a mouse model of allergic airways disease (AAD). BALB/c mice were intraperitoneally sensitized to ovalbumin (OVA) and intranasally challenged with OVA 12-15 days later to induce AAD. Mice were infected with non-typeable H. influenzae during or 10 days after sensitization, and the effects of infection on the development of key features of AAD were assessed on day 16. T-helper 17 cells were enumerated by fluorescent-activated cell sorting and depleted with anti-IL-17 neutralizing antibody. We show that infection in AAD significantly reduced eosinophilic inflammation, OVA-induced IL-5, IL-13 and IFN-γ responses and AHR; however, infection increased airway neutrophil influx in response to OVA challenge. Augmented neutrophilic inflammation correlated with increased IL-17 responses and IL-17 expressing macrophages and neutrophils (early, innate) and T lymphocytes (late, adaptive) in the lung. Significantly, depletion of IL-17 completely abrogated infection-induced neutrophilic inflammation during AAD. In conclusion, H. influenzae infection synergizes with AAD to induce Th17 immune responses that drive the development of neutrophilic and suppress eosinophilic inflammation during AAD. This results in a phenotype that is similar to neutrophilic asthma. Infection-induced neutrophilic inflammation in AAD is mediated by IL-17 responses.

Topics: Animals; Asthma; Disease Models, Animal; Eosinophils; Female; Haemophilus Infections; Haemophilus influenzae; Immunity, Cellular; Inflammation; Interferon-gamma; Interleukin-13; Interleukin-17; Interleukin-5; Mice; Mice, Inbred BALB C; Neutrophils; Ovalbumin; Phenotype; T-Lymphocytes, Regulatory; Th17 Cells

New pathophysiologic concepts are needed to explain the clinically observed connection between the allergic diathesis and otitis media. Although mast cells, unlike lymphocytes, are common in the normal middle ear mucosa, their potential role in innate immunity of the middle ear and in the expression of inflammatory responses in that space to bacterial challenge, as opposed to allergy, has received relatively little attention.. In the current study, we examine the contributions of mast cells to the pathogenesis of bacterially induced inflammation in the middle ear and thus to otitis media.. Wild-type mice, mast cell-deficient mice, and mast cell-deficient mice whose mast cell populations were restored by transplantation of bone marrow-derived mast cells were challenged by using models of bacterial and allergic middle ear inflammation.. Our results indicate that mast cells account for a substantial proportion of the innate immune response to bacteria in the middle ear.. This mechanism may link responses to allergy and infection in the middle ear mucosa, and thus the mast cell may be a critical control element in the pathogenesis of otitis media.

Topics: Animals; Bone Marrow Cells; Cells, Cultured; Drug Combinations; Ear, Middle; Female; Haemophilus Infections; Haemophilus influenzae; Hypersensitivity; Injections; Mast Cells; Mice; Mice, Congenic; Mice, Mutant Strains; Otitis Media; Ovalbumin

Immunogenicity of the lipid A component of Haemophilus somnus lipooligosaccharide in cattle and mice was examined after purification, detoxification, and covalent conjugation to a protein carrier. After 2 inoculations, a substantial antibody response was induced in most cattle to lipid A and the protein carrier. To determine whether antibodies to lipid A would be protective, 5 x 10(7) colony-forming units of H somnus strain 649 were administered IV to endotoxin-responsive (C3H/HeN) mice. In one study, 8 of 13 C3H/HeN mice aborted when inoculated. In contrast, abortion did not result when mice were inoculated with the same dose of an isolate of H somnus normally found in the prepuce or with the rough mutant Escherichia coli J5. In addition, endotoxin-nonresponsive (C3H/HeJ) mice were significantly (P = 0.03) more resistant to abortion by strain 649 than were C3H/HeN mice, but inoculated C3H/HeN mice were only slightly more resistant to H somnus abortion, compared with control mice. Although a large antibody response to lipid A was detected, there was no significant difference in the immunized group between mice that aborted and mice that delivered normally. Thus, lipooligosaccharide and other properties of virulent H somnus strains may contribute to abortion in mice.

Topics: Abortion, Veterinary; Animals; Antibodies, Bacterial; Bacterial Vaccines; Cattle; Cattle Diseases; Cricetinae; Disease Models, Animal; Female; Haemophilus; Haemophilus Infections; Hemocyanins; Lipid A; Mesocricetus; Mice; Mice, Inbred C3H; Ovalbumin; Pregnancy; Rats; Rats, Inbred Strains; Vaccines, Synthetic