Humoral and cell mediated immune responses to porins of Salmonella typhi

Humoral and cell mediated immune responses were studied in control, infected and immunized-infected mice at different time intervals. The levels of antiporin antibodies were found to be higher throughout the study period in immunized-infected group in which 87.5% protection was observed by mouse potency test. A significant increase in stimulation index of lymphocyte blast transformation as well as delayed type hypersensitivity response was observed in the same group as compared to infected and control group when porins were used as antigens. Using nonspecific mitogens like PHA and Con A the lymphocyte proliferation was maximum in control group whereas a significant depression was observed in infected mice. It is indicated from this study that porins are excellent antigens interacting efficiently with both arms of the host immune systems which could play a role in providing protection against the disease.