Animals Model With Cryptosporidiosis And The Immune Mechanism

Objective: To establish a model in rats with Cryptosporidium from water,carry out helper T lymphocyte detection,detect the change of CD4~+,CD8~+,CD4~+/CD8~+ in every group;To detect the cytokines IL-2 changes of suckling mice infected with Cryptosporidium.Methods:30 SD rats were randomly divided into 3 groups:malnutrition group,immunosuppressed group,blank control group. Malnutrition group was fed with 8% low protein forage; Immunosuppressed group was administered with dexamethasone (DEX)for 11 days. Then,rats in three groups were orally inoculated twice by 3×10~3 oocysts of C.parvum which were acquired by filtering the fresh water.Kill all the rats after the second infection on the 7th day.Do intestine endothelial tissue biopsy.Observe pathological section of the oocysts of C.parvum infection conditions.Prepare the cell suspending liquid of spleen,intestinal submucous aggregated lymphatic follicles,intestinal endothelium.The value of CD4~+/CD8~+ in cell suspending liquid was analyzed with flow cytometry;Pairs of 4-day-old suckling mice of KM species of Cryptosporidium oocysts fed 3×10~3 everyone. A week later, counting neonatal rat peritoneal macrophage phagocytosis of chicken red blood cell phagocytosis percentage and phagocytic index were observed in mice infected with Cryptosporidium oocysts spleen cell factor IL-2 changes. Results:The rats weight in blank control group increase obviously ,the spleen grows well, the lymphoid nods are clear, no CSO grows in immunosuppressed rats infected by Cryptosporidium. The rats weight in malnutrition group increase slowly,mucous membrane of small intestine lymph nods are clear,CSO field plant in small intestine. Spleen development is serious insufficient. No mucous membrane of small intestine lymph nods can see , CSO field plant in small intestine. The CD4~+ value,CD8~+ value,CD4~+/CD8~+ ratio of spleen, intestine and mucosal T lymphoid tissue was statistically significant(p<0.05) compared with the malnutrition group and blank group; infected with Cryptosporidium parvum oocysts in newborn mice whose chicken red blood cells to reduce the percentage of phagocytic index and phagocytic cell factor IL-2 concentration, as compared with the control group, the difference was statistically significant (p <0.05).Conclusion:Compared with the blank group, after the infection of oocysts of C.parvum, the value of CD4~+,CD4~+/CD8~+ decrease obviously in the other two groups; Cytokines IL-2 concentration of suckling mice infected with Cryptosporidium oocysts is up.