OBJECTIVETo investigate the changes in cellular apoptosis of Peyer's patches in severely scalded mice, and to explore its role in the pathogenesis of gut barrier damage.

METHODSForty BALB/c mice were randomly divided into normal control, 12 post-scald hour (12PSH), 24PSH and 72PSH groups, with 10 in each group. The mice in all PSH groups were inflicted with 20% TBSA full-thickness scald on the back. The mice in all the groups were sacrificed at different time points, and Peyer's patches were harvested from all the mice for HE staining, DNA gel electrophoresis, and flow cytometry ( FCM) examination with FITC conjugated Annexin-v and propidium iodide( PI) staining of cells.

RESULTSHE staining revealed that there were relatively abundant apoptotic cells scattering in Peyer's patches of scalded mice . DNA electrophoresis of Peyer's patches revealed typical " ladder" pattern at all indicated time points in scalded mice. Apoptotic percentage of detached Peyer's patches cells in control and scalded group were (4. 9+/-2. 1)% , (26.7+/-3. 1)% , (21.6 +/-4.0)% ,(12. 8 +/-2.0)% , respectively, and the percentage reached the peak at 12 PSH.

CONCLUSIONApoptosis is a principle modality of cell death of small intestinal Peyer's patches lymphocytes in severely scalded mice, and it might contribute to immunity barrier failure of intestinal wall after severe thermal injury.

Animals ; Apoptosis ; Burns ; immunology ; metabolism ; Intestine, Small ; cytology ; immunology ; Lymphocytes ; cytology ; Male ; Mice ; Mice, Inbred BALB C ; Peyer's Patches ; cytology

Vaccination is one of the most successful applications of immunology and for a long time has depended on parenteral administration protocols. However, recent studies have pointed to the promise of mucosal vaccination because of its ease, economy and efficiency in inducing an immune response not only systemically, but also in the mucosal compartment where many pathogenic infections are initiated. However, successful mucosal vaccination requires the help of an adjuvant for the efficient delivery of vaccine material into the mucosa and the breaking of the tolerogenic environment, especially in oral mucosal immunization. Given that M cells are the main gateway to take up luminal antigens and initiate antigen-specific immune responses, understanding the role and characteristics of M cells is crucial for the development of successful mucosal vaccines. Especially, particular interest has been focused on the regulation of the tolerogenic mucosal microenvironment and the introduction of the luminal antigen into the lymphoid organ by exploiting the molecules of M cells. Here, we review the characteristics of M cells and the immune regulatory factors in mucosa that can be exploited for mucosal vaccine delivery and mucosal immune regulation.
Administration, Oral ; Animals ; Antigens, Bacterial/*immunology ; Antigens, Viral/*immunology ; Bacterial Vaccines/administration & dosage/*immunology ; Humans ; Immunity, Mucosal ; Intestinal Mucosa/cytology/*immunology ; Peyer's Patches/cytology/*immunology ; Viral Vaccines/administration & dosage/*immunology

In order to determine the role of Peyer's patch lymphocytes (PPL) in self-clearing of Cryptosporidium parvum infection in murine models, changes in PPL subsets, their cytokine expression, and in vitro IgG1 and IgA secretions by PPL were observed in primary- and challenge-infected C57BL/6 mice. In primary-infected mice, the percentages of CD4+ T cells, CD8+ T cells, sIgA+ B cells, IL-2+ T cells, and IFN-gamma+ T cells among the PPL, increased significantly (P < 0.05) on day 10 post-infection (PI). Secretion of IgG1 and IgA in vitro by PPL also increased on day 10 PI. However, all these responses, with the exception of IgG1 and IgA secretions, decreased in challenge-infected mice on day 7 post-challenge (= day 13 PI); their IgG1 and IgA levels were higher (P > 0.05) than those in primaryinfected mice. The results suggest that murine PPL play an important role in self-clearing of primary C. parvum infections through proliferation of CD4+, CD8+, IL-2+, and IFN-gamma+ T cells, and IgG1 and IgA-secreting B cells. In challenge infections, the role of T cells is reduced whereas that of B cells secreting IgA appeared to be continuously important.
Animals ; Antibodies, Protozoan/analysis/metabolism ; Cattle ; Cryptosporidiosis/*immunology/parasitology ; Cryptosporidium parvum/*immunology ; Feces/parasitology ; Female ; Humans ; Immunoglobulin A/analysis/biosynthesis ; Immunoglobulin G/analysis/biosynthesis ; Interferon-gamma/analysis/biosynthesis ; Interleukin-2/analysis/biosynthesis ; Lymphocytes/*immunology ; Male ; Mice ; Mice, Inbred C57BL ; Peyer's Patches/cytology/*immunology ; Specific Pathogen-Free Organisms