QUANTITATIVE ALTERATIONS IN POPULATIONS OF SURFACE RECEPTOR-BEARING MONONUCLEAR CELLS WITHIN RAT SKIN GRAFT RECIPIENTS

Abstract

The levels of complement receptor leukocytes (CRL) and Ig[immunoglobulin]M+ leukocytes (B [bone marrow-derived] cells) in the regional lymph nodes draining an allogeneic Lewis (LEW) skin graft and a syngeneic DA skin graft were monitored in DA rats during primary and secondary graft rejection. The levels of CRL and B cells in the regional lymph nodes draining the allograft were not significantly different from the levels in the control lymph nodes draining the isograft at any interval from day (D)2-14 after primary skin grafting. Rats used in secondary rejection studies were grafted with LEW and DA skin 30 days after primary grafting. The levels of CRL in the regional lymph nodes draining an allograft during secondary rejection were significantly elevated (P < 0.01) on D8 and D10 when compared with levels in the lymph nodes draining an isograft. The levels of B cells in the lymph nodes draining an allograft were also significantly elevated (P < 0.02) compared to the level in the lymph nodes draining the isograft on D8 and D12 after secondary grafting. An increase in the number of detectable Fc receptor+ (FcR) leukocytes was previously reported in recipients rejecting a primary allograft. A change in the proportion of CRL that were B cells did not occur in the lymph nodes draining the allograft. An increase of 21% in the percentage of Fc R+ leukocytes that were not B cells occurred in D6 in the lymph nodes draining the allograft. The percentage of Fc R+ leukocytes that were IgM- (Fc R+ IgM-) in the lymph node draining an allograft vs. an isograft remained significantly elevated (P < 0.05) on D8. The Fc R+ IgM- population existed without a decrease in the percentage of B cells, the Fc+ receptors detected were expressed on an indigenous population and apparently did not represent a specific accumulation of Fc R+ non-B cells.