The effect of measles virus infection on T and B lymphocytes in the mouse. I. Suppression of helper cell activity

The effect of measles virus infection on T and B lymphocytes in the mouse was studied with a system of cell cooperation for production of an anti hapten response. The effect of virus was studied by infecting helper cell or antibody forming precursor cell donors with measles virus at various times before cell transfer into recipient mice and measuring the anti hapten response after challenge with carrier hapten conjugates. These studies indicate that measles virus produces a significant reduction in the anti hapten response. This reduction in antibody formation is caused predominantly by measles virus suppression of T helper cell function and possibly by a lesser effect on B cell function. The suppression of T cells is transient and corresponds to the time during which measles antigen can be demonstrated in the mouse spleens. Although infectious virus cannot be recovered from the lymphocytes, the suppression of T cells could only be demonstrated after inoculation with a virus strain capable of replicating in the mouse. These findings suggest that the virus may be present in a non infectious or defective form. The effect of measles virus in T cells does not appear to be due to a depletion of T cells. The possible mechanisms for the suppressive effect are discussed.