Characterization of peripheral blood CD8/11 cells in bone marrow transplant recipients. II. Two distinct populations of CD8/11 cells.
Flow cytometric analysis of mononuclear cell surface antigens identified 2 distinct populations of CD8/11 cells in the peripheral blood of recovering bone marrow transplant (BMT) recipients. These populations were distinguished based on differential CD8 antigen expression. One population expressed high-surface density CD8 (CD8 bright/11); the other population expressed low-surface density CD8 (CD8 dim/11). The surface expression of CD11, the C3bi receptor on lymphocytes, is similar in CD8 right/11 and CD8 dim cells. Thus, although 13 BMT recipients had elevated CD8/11 cells (mean = 27% +/- 9%; normal range mean = 7.4 +/- 3.3%), the percent of CD8 bright/11 cells versus CD8 dim/11 cells varied. The majority of cells in patients with a predominant CD8 right/11 phenotype did not express CD16 (Fc gamma receptor). In contrast, the CD8 dim/11 cells coexpressed CD16. When functional studies were performed, we observed high numbers of CD8 right/11 cells correlated with low natural killer (NK) lytic activity, while patients with less than 25% CD bright/11 cells had high NK activity. Analysis of interleukin 2 (IL-2) production revealed that none of the peripheral blood mononuclear cells (PBMC) from BMT patients synthesized IL-2 at less than 1.5 months posttransplant. However, cells from some patients began to synthesize IL-2 at approximately 2 months posttransplant. It is likely that both populations of CD8/11 cells have an impact on the regeneration and regulation of the immune system in BMT recipients.
Gottschalk
L R
LR
Department of Immunology/Microbiology, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612.
Kaizer
H
H
Gebel
H M
HM
D000943:Antigens, Differentiation / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D016026:Bone Marrow Transplantation; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006801:Humans; D007113:Immunity, Innate; D007376:Interleukin-2 / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000145:classification / Q000276:immunology*; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D013997:Time Factors
D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D007376:Interleukin-2