The Journal of Immunology, Vol 146, Issue 12 4278-4281, Copyright © 1991 by American Association of Immunologists

ARTICLES

Inhibition of cytolytic lymphocytes by homologous restriction factor. Lack of species restriction

LS Zalman, MA Brothers and KL Strauss
Scripps Clinic and Research Foundation, Department of Immunology, La Jolla, CA 92037.

Homologous restriction factor (HRF) has been shown to inhibit complement-mediated lysis in a species-restrictive manner. Human HRF is able to block lysis by human complement but not by complement from other species. HRF has also been found in the membrane of lymphokine- activated killer (LAK) cells. When this HRF is inserted into sheep erythrocyte membranes, it is able to protect the erythrocyte from LAK cell lysis. In this report, we show that while HRF can inhibit human complement but not rat complement-mediated hemolysis, it is able to inhibit LAK cell lysis by both human and rat LAK cells. HRF is therefore a more general protective protein than has been previously thought.