1Prevention of immune dysfunction, vitamin E deficiency, and loss of Cryptosporidium resistance during murine retrovirus infection by T cell receptor peptide immunization

Abstract

C57BL 6 mice were immunized with peptide corresponding to CDR1 of human T cell receptor (TCR) Vß8.1 and immunoglobulin lambdachain MCG after murine retrovirus (LP-BM5) infection. Immunization with the TCR peptide largely prevented the retrovirus-induced reduction in B and T cell proliferation, tissue vitamin E, and Th1 (T helper 1) cytokine (IL-2 and IFN-τ) secretion. The TCR peptide also prevented retroviral stimulation of Th2 cytokine (IL-6 and IL-10) production and lipid peroxidation. Cryptosporidiosis was established in all retrovirus immunosuppressed mice, while non-retrovirus infected mice were refractory to parasite infection. Cryptosporidium parvum colonization of intestinal villi was significantly reduced in immunosuppressed animals that received TCR Vß8.1 peptide immunization. Thus, immune dysfunction with the loss of parasite resistance, induced by murine retrovirus infection, was largely prevented by TCR Vß CDR1 peptide immunization. However, no significant change in survival of the retrovirally infected mice was observed as the lymph nodes continued to expand which induced eventual death from asphyxiation.