CHARACTERIZATION OF LA-POSITIVE PERITONEAL-EXUDATE CELLS WHICH AUGMENT CONCANAVALIN A RESPONSE OF T-CELLS

Ia antigens on mouse peritoneal exudate cells (PEC) as well as splenic non-B cells were detected by radioimmunoassay using various anti-Ia sera and radiolabeled specific anti-allotype sera. To remove B cells from PEC and the spleen cell suspensions, anti-ThB was utilized. This antiserum, in the presence of rabbit complement, effectively abrogated the lipopolysaccharide (LPS) response and depleted more than 95% of Ig-bearing cells of PEC and spleen suspensions. After the treatment with anti-ThB and complement, Ia was still detectable by radioimmunoassay on residual PEC and spleen cells. The subregion specificity of the Ia detected on these non-B cells was found to be I-A and I-E·C. Consistent results were observed in functional assays where the PEC cells which reconstitute the proliferative response of pure T cells to concanavalin A (Con A) were also found to express Ia antigens of the I-A or I-E·C subregion. © 1979.