T-cells of virus-infected mice produce a lymphokine which activates the autoreactivity of intact mouse lymphocytes.

The role of lymphokines was estimated in induction of autoreactive T-cells during Langat virus infection in mice. It was shown that in vitro cultured splenocytes from virus-infected animal containing autoreactive lymphocytes (ARL) spontaneously produce a lymphokine which is capable to activate the autoreactivity of lymphocytes derived from the spleen of intact syngeneic mice. The capacity of this lymphokine to activate the autoreactivity of acceptor cells within 2 hr was demonstrated by local graft-versus host reaction (GVHR) in the donor-recipient system. According to their surface markers (theta-antigen expression, absence of immunoglobulins) the lymphokine activating autoreactivity (LAA) producers may belong to T-lymphocyte population. Autoreactivity could be induced by the lymphokine only if the LAA producers and acceptors were compatible by the major histocompatibility complex antigens.