MEASLES VIRUS-INDUCED IMMUNE SUPPRESSION IN THE COTTON RAT (SIGMODON HISPIDUS) MODEL DEPENDS ON VIRAL GLYCOPROTEINS

Immune suppression during measles accounts for most of the morbidity a nd mortality associated with the virus infection, Experimental study o f this phenomenon has been hampered by the lack of a suitable animal m odel, We have used the cotton;at to demonstrate that mitogen-induced p roliferation of spleen cells from measles virus-infected animals is im paired. Proliferation inhibition is seen in all lymphocyte subsets and is not dependent on viral replication, Cells which express the viral glycoproteins (hemagglutinin and fusion protein) transiently by transf ection induce proliferation inhibition after intraperitoneal inoculati on, whereas application of a recombinant measles virus in which measle s, virus glycoproteins are replaced with the vesicular stomatitis viru s G protein does not hare an antiproliferative effect, Therefore, in v ivo expression of measles virus glycoproteins is sufficient and necess ary to induce inhibition of lymphocyte proliferation.