ovalbumin and Clostridium-Infections

Low Clostridium leptum levels are a risk factor for the development of asthma. C. leptum deficiency exacerbates asthma; however, the impact of early-life C. leptum exposure on cesarean-delivered mice remains unclear. This study is to determine the effects of early-life C. leptum exposure on asthma development in infant mice.. We exposed infant mice to C. leptum (fed-CL) and then induced asthma using the allergen ovalbumin (OVA).. Fed-CL increased regulatory T (Treg) cells in cesarean-delivered mice compared with vaginally delivered mice. Compared with OVA-exposed mice, mice exposed to C. leptum + OVA did not develop the typical asthma phenotype, which includes airway hyper-responsiveness, cell infiltration, and T helper cell subset (Th1, Th2, Th9, Th17) inflammation. Early-life C. leptum exposure induced an immunosuppressive environment in the lung concurrent with increased Treg cells, resulting in the inhibition of Th1, Th2, Th9, and Th17 cell responses.. These findings demonstrate a mechanism whereby C. leptum exposure modulates adaptive immunity and leads to failure to develop asthma upon OVA sensitization later in life.

Topics: Animals; Animals, Newborn; Asthma; Clostridium; Clostridium Infections; Disease Models, Animal; Female; Immune Tolerance; Immunity, Cellular; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; T-Lymphocytes, Regulatory

Efficient delivery of antigen to mucosal immune tissues is an essential part of mucosal vaccination. Claudin-4 is expressed on the epithelial cells that cover the mucosal immune tissues. We previously found that claudin-4-targeting is a promising strategy for mucosal vaccination by using a claudin-4 binder, the C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE). Substitution of Asn and Ser at positions 309 and 313, respectively, with alanine increased the affinity of C-CPE for claudin-4. However, application of the C-CPE mutant as a mucosal vaccine has never been tried. Here, we investigated whether the C-CPE mutant could serve as a mucosal vaccine. We used ovalbumin (OVA) as a model antigen and fused the C-CPE mutant to it. The resultant fusion protein was bound to claudin-4. When mice were immunized with the C-CPE mutant-fused OVA, OVA-specific serum IgG and nasal IgA increased relative to levels in mice immunized with a C-CPE-fused antigen. Immunization with the C-CPE mutant-fused OVA activated Th1- and Th2-type responses and led to increased anti-tumor activity against OVA-expressing thymoma cells relative to that of mice immunized with the C-CPE-fused antigen. These findings suggest that the alanine-substituted C-CPE mutant shows promise as a claudin-targeted mucosal vaccine.

Topics: Alanine; Animals; Bacterial Vaccines; Claudin-4; Claudins; Clostridium Infections; Clostridium perfringens; Enterotoxins; Enzyme-Linked Immunosorbent Assay; Female; Mice; Mice, Inbred BALB C; Mucous Membrane; Ovalbumin

The C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) is a claudin-4 binder. Very recently, we found that nasal immunization of mice with C-CPE-fused antigen activated antigen-specific humoral and mucosal immune responses and that the deletion of the claudin-4-binding domain attenuated the immune responses. C-CPE-fusion strategy may be useful for mucosal vaccination. C-CPE is a fragment of enterotoxin, and the safety of C-CPE-fused protein is very important for its future application. In the present study, we investigated whether C-CPE-fused antigen induces immune responses without mucosal injury by using ovalbumin (OVA) as a model antigen. Immunohistochemical analysis showed that claudin-4 was expressed in epithelial cell sheets bordering the nasal cavity. Nasal immunization with C-CPE-fused OVA dose-dependently elevated the OVA-specific serum IgG titer, which was 1000-fold greater than the titer achieved by immunization with OVA or a mixture of OVA and C-CPE at 5 microg of OVA. Nasal immunization with C-CPE-fused OVA (5 microg of OVA) activated Th1 and Th2 responses. Histological analysis showed no mucosal injury in the nasal cavity or nasal passage. C-CPE-fused OVA exhibited mucosal vaccination without mucosal injury. These findings indicate thatclaudin-4-targeting using C-CPE can be a potent strategy for mucosal vaccination.

Topics: Administration, Intranasal; Animals; Claudin-4; Clostridium Infections; Clostridium perfringens; Dose-Response Relationship, Immunologic; Enterotoxins; Female; Immunity, Mucosal; Immunoglobulin G; Immunohistochemistry; Membrane Proteins; Mice; Mice, Inbred BALB C; Ovalbumin; Peptide Fragments; Th1 Cells; Th2 Cells; Vaccines, Subunit

Bifidobacterium is a dominant bacterial species among commensals in the human intestine and is thought to have probiotic immunomodulatory effects. In this study, we investigated the effect of the association with Bifidobacterium pseudocatenulatum JCM 7041 (Bp) on dietary ovalbumin (OVA)-specific immune responses using germ-free OVA-specific T cell receptor transgenic mice (OVA23-3 mice). We established germ-free OVA23-3 mice, and then associated with Bp (BIF group) or without (CONT group) and additionally associated with segmented filamentous bacteria (SFB) and clostridia in both groups. BIF and CONT mice were fed an egg-white diet containing OVA for 1 week. Cytokine production in response to OVA by cells of Peyer's patches (PPs) and lamina propria (LP) from the small and large intestine was measured. Interferon (IFN)-gamma and interleukin (IL)-6 production by PP cells from BIF group mice was lower than that of the CONT group. The proportion of PP cells expressing CD4+CD62L(low), an activated/memory T cell phenotype, was higher in BIF group mice than the CONT group. Furthermore, LP cells from the small intestine in Bp-associated mice showed a tendency to produce slightly lower IFN-gamma and IL-6, while the cells from large intestine produced markedly higher IFN-gamma, IL-5 and IL-6 than those in the CONT group. The pattern of cytokine production by PP in BIF animals was similar to those isolated from conventional mice. These results suggest that intestinal association with Bp might down-regulate excessive immune responses to dietary antigens of the small intestine but enhance those of the large intestine.

Topics: Administration, Oral; Animals; Bifidobacterium; CD4-Positive T-Lymphocytes; Clostridium; Clostridium Infections; Colony Count, Microbial; Diet; Down-Regulation; Germ-Free Life; Immunity, Mucosal; Interferon-gamma; Interleukin-6; Intestine, Large; Intestine, Small; L-Selectin; Lymphocyte Activation; Mice; Mice, Transgenic; Organ Specificity; Ovalbumin; Receptors, Antigen, T-Cell