Abstract:To investigate the immunoprotection of the recombinant BCG vaccine of Cryptosporidium parvum (C. parvum),100 BALB/c mice were divided into 4 groups randomly and injected with rBCG-CP15/60-23 (experiment group),BCG (BCG group),BCG-PMV262 (vector group) and PBST (control group),respectively. Then the levels of CD+4,CD+8 and cytokines in supernatant as well as the splenocytes of IgG in serum were detected. Mice in each group were challenged with C. parvum for further observation. Results showed that rBCG-CP15/60-23 has induce the cell immunity and humoral immunity reaction in mice. The level of IgG in mice immunized with rBCG-CP15/60-23 had increased gradually since 2 weeks after immunifaction,with significant differences compared to the BCG group and Vector group(P<0.01). Both the proliferation of CD4+ T cells and the ratio of CD+4 to CD+8 were obviously enhanced (P<0.05). The levels of IL-2,IL-12 and IFN-γ from the splenocytes in experimental group were higher than that of control and BCG group(P<0.05),but there was no statistically significant difference on level of IL-12 among these 4 groups(P>0.05). The delitescence of mice challenged by oral exposure to C. parvum was prolonged to 4-6days but the duration of evacuation in experiment group was shrunk obviously. Furthermore,the amount of evacuated oocysts in experiment group was decreased by 40%-60%,and the difference between experiment group and BCG group or control group were prominent(P<0.05). All these results indicated that a favorable immunoprotection could be induced by rBCG-CP15/60-23.
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