RESUMO
The effect of rat cytomegalovirus (CMV) infection on immune function was studied in rats with collagen induced arthritis, an experimental model of autoimmunity targeted to cartilage and previously shown to be greatly augmented in severity by rat CMV. Rat CMV infection induced an early (7 to 14 day), 2.5-fold increase in circulating B cells (SIgG+) which was associated with moderate increases in the titers of serum IgG antirat type II collagen antibody. A significantly increased skin test reactivity (p less than 0.025) to rat type II collagen was detected at Day 14 and followed a small increase in numbers of W3/25+ T-helper cells in peripheral blood noted at Day 8. A 3-fold expansion of OX8+ peripheral lymphocytes, occurring maximally at Day 8, was tentatively identified as a natural killer cell population by functional 51Cr-release assays. Our data indicate that rat CMV augmentation of collagen induced arthritis is associated with a generalized but modest increase in immune reactivity towards rat type II collagen and with significant alterations of peripheral lymphocyte subsets.
