Expression of IL-2 receptor/p75 on lymphocytes from patients with rubella

We analyzed the Interleukin-2 receptor (IL-2R) expression on fresh lymphocytes from three patients with rubella. Flow cytometric analysis demonstrated that lymphocytes from the patients expressed a considerable amount of IL-2R/p75 recognized by Mik-beta 1 monoclonal antibody (MoAb), although they did not react with anti-IL-2R/p55 (CD25) MoAb. The expression of IL-2R/p75 reached a peak at the end of the acute phase of illness. Fresh lymphocytes from rubella patients showed a marked proliferative response to IL-2, which was completely inhibited by Mik-beta 1, indicating that their IL-2R is a functional receptor. The present data suggest that IL-2R/p75 expression is involved in the host immune response triggered by the rubella virus.