Impaired expression of interleukin-2 receptor (IL2R) in the immunosuppressed burned patient: reversal by exogenous IL2.
The capability of exogenous recombinant Interleukin 2 (rIL2) to increase expression of the IL2 receptor (IL2R), and to augment the in vitro proliferative response of lymphocytes from immunosuppressed burned patients (5-80% full-thickness burns) was examined. Throughout the postburn period the percentage of IL2R-bearing cells in Concanavalin A-activated cultures of patients' peripheral blood mononuclear cells (PBMC) was measured by direct immunofluorescence with monoclonal anti-IL2R antibodies. Mitogen-induced IL2R expression was decreased by 40-90% in cultures of patients' PBMC, parallel to their reduced alloreactivity. During this period of immunosuppression supplementation of the mitogen-activated cultures with recombinant IL2 (20 U/ml) significantly increased the number of IL2R-expressing cells in all patients studied. However, IL2-induced enhancement of blastogenesis in the MLR was observed only with the patients who, in mitogen-activated cultures, sustained numbers of IL2R-endowed cells at least 50% of their baseline (the level within the first 24 hours postburn). Also, unstimulated PBMC of the same responding patients demonstrated a restoration of proliferation in the presence of rIL2. These patients were survivors. Thus the proliferative response correlated well with the number of Con A- but not rIL2-induced IL2R-expressing cells. These results suggest that in burned patients, IL2 up-regulates its receptors, but they may represent low-affinity nonfunctional receptors. Thus thermal injury appears to affect expression of functional (high-affinity) receptors.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002056:Burns / Q000276:immunology*; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009000:Monocytes; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D011971:Receptors, Immunologic / Q000187:drug effects / Q000276:immunology*; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology
D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins