Exploration The Physiological Significance Of Cecum By Listeria Infection Model

The cecum is a part of the intestine,and its physiological and pathological functions are rarely studied.Previous studies have shown thateither RIP3 or MLKL deletion mice can be significantly protected responded to high dose of TNF-a(a key stimulus of necroptosis)via tail vein injection.In the cecal of wild mice,the obvious damage of organ necrosis was observed first,but no obvious necrosis was observed in the other intestinal parts.importantly,the expression of phosphorylated MLKL was significantly increased in human appendicitis samples.All of these indicate that the cecum is a tissue that is highly sensitive to necroptosis,but the specific physiological significance of this property is still unknown.Necroptosis is generally thought to be involved in host immune defense against infectious pathogens.Therefore,mice model for infection with Listeria monocytogenes will be used in this current study to investigate whether the cecal,which is highly sensitive to necrosis-like apoptosis,plays a protective role in the immune responses.By analyzing the T cell differentiation and immune effects of wild type mice infected with Listeria and cecal resected mice,we observed that the cecum plays a role in the immune response:during the activation of CD8+T cells,whether the first infection or the secondary infection,and there was no significant difference between the cecal resection mice and the normal mice.In the formation of memory CD8+ T cells,cecal resection also had no effect.However,in the differentiation of antigen-specific CD8+ T cells,the degree of differentiation of cecal resected mice was significantly lower than that of normal mice.At the same time,the proportion of cells producing cytokines decreased in mice after cecal resection.Therefore,the cecum does not affect the differentiation of memory T cells,but it affects the differentiation and immediate response of effector T cells.However,in the subsequent detection of MLKL knockout mice,no difference was found in the immune responses to Listeria:MLKL knockout mice and wild type mice,whether in CD8+T cell differentiation or there are no significant differences in cytokine production.These results indicate that the cecum does have a certain effect on the immune effect of T cells,but does not depend on the cell necrosis-like apoptotic signaling pathway.The cecal is highly sensitive to necroptosis,which is highly sensitive to necroptosis,and its role in the immune system requires further experimentation.