immune responses to infection with Friend retrovirus (Murine leukaemia virus)

The defence of a host against viral infections is strongly influenced by cytokines. We investigated the role of the B-cell stimulating cytokines IL-5 and IL-6, and the immuno-suppressive cytokine IL-10, during primary and secondary immune responses in mice against infection with Friend retrovirus (FV) (Murine leukaemia virus). IL-5N/N mice were com-parable to C57BL/6 wild-type mice in their ability to control acute FV infection. In contrast, IL-6N/N and IL-10N/N mice showed significantly enhanced virus loads in spleen cells. However, this impaired control of acute FV replication did not alter the long-term control over persistent FV in IL-6N/N and IL-10N/N mice. Immunization with a live attenuated vaccine virus prior to challenge protected all thre