Exploration To The T Lymphocytes From Mouse Intestinal Immune System Effected By Broad-spectrum Antibiotics Cefepime

Intestinal tract is one of major organ of digestion in animal or human body, and is thelargest immune organ surface area. Intestinal tract is also an important barrier to defensepathogenic microorganisms invasioning to the body’s. The result of animal organism evolved isthe mutual benefit between gut-associated lymphoid tissue and intestinal tract symbiosis flora.More than100trillion microbes, most of these are non-pathogenic microorganisms, exist in thehealthy human intestinal tract and their homeostasis are closely related with the health of thebody. The widely used in the livestock of broad-spectrum antibiotics has serious impacts on thehealth of animal and human,such as overuse of broad-spectrum antibiotics is susceptibility toinflammatory bowel disease(IBD) in recent years. To explore the changes of intestinal immuneresponses in mice, we use β-lactam antibiotic cefepime injected BALB/c mice establishedantibiotic intervention model. Flow cytometry detect immune indicators of peripheral lymphoidorgans, intestinal secondary lymphoid organs and intestinal tissue of mice, and apply intestinalpathogen infection model to evaluate the susceptibility to pathogens of model. The resultsshowed that the colony forming units of Aerobe, Anaerobes, Enterococcus, Enterobacter,Bifidobacterium and Lactobacillus in intestinal tract are significantly lower; the number ofCD3+T cell in spleen, mesenteric lymph nodes, Pyle’s knot and intestinal lamina propria arereduced; CD3+T cells, CD3+CD4+T cells, CD3+CD8+T cell subsets are decreased in spleen,mesenteric lymph nodes, Pyle’s knot and intestinal lamina propria after injected intravenouslythe minimum therapeutic dose of antibiotics to BALB/c mice. Meanwhile, Th cell differentiationof these parts is also be affected, with the Th2-type cytokines increased the expression level, theexpression of Th1-type cytokines, Th17-typecytokines and the number ofCD4+CD25+Foxp3+Tregs subsets are decreased. The above-mentioned phenomenondemonstrates that minimum therapeutic dose of antibiotic injections could cause intestinal floradisorder, and affect the peripheral lymphoid organs, intestinal secondary lymphoid tissue andintestinal tissue of immune system development that make them present the status of immatureimmune system, that is CD3+T cell subsets and their levels were lower than normal, T helpercell immune response to Th2-type direction polarizes. We also analyzed the changes ofantibiotic intervention mice model after infected Salmonella typhimurium, experimental micehad a serious pathological changes, and part of mice died just after infected indicated that enhanced susceptibility of mice to intestinal pathogens. Above all, our results support thishypothesis, antibiotic intervention changed the host intestinal flora balance, and maybe induce Tcell of intestinal immune system dysfunction, thereby affect the health of the body.