Regeneration of T cell subpopulations after bone marrow transplantation: cytomegalovirus infection and lymphoid subset imbalance.
Immune reconstitution was studied serially by using T lymphocyte cell surface differentiation antigens in 37 individuals receiving bone marrow transplants. Antigen expression was assessed by immunofluorescence analysis using monoclonal antibodies to T lymphocytes including Leu-3, which defines a T lymphocyte subpopulation in healthy individuals with T helper or inducer activity (L3+), and Leu-2, which defines a T lymphocyte subpopulation in healthy individuals with T helper or inducer activity (L3+), and Leu-2, which defines a T lymphocyte subpopulation with suppressor or cytotoxic activity (L2+). These studies demonstrated that the L2+ subpopulation regenerated more rapidly after transplant than did the L3+ subpopulation. Imbalances between these two T lymphocyte subpopulations, indicated by a decreased L3/L2 ratio, persisted for periods up to 12 mo post-transplant. Expression of a cell surface antigen associated with immature lymphocytes (OKT-10), and of HLA-DR (Ia-like) antigens was markedly increased during the post-transplant period. HLA-DR antigen expression did not appear related to immune activation in that increased reactivity was not detected with a monoclonal antibody (anti-TAC) specific for activated T cells. These observations in bone marrow transplant recipients and other disorders characterized by lymphoid restoration or immaturity indicate that inversion of the normal L3/L2 ratio and increased expression of OKT-10 and HLA-DR antigens may be features of a regenerating immune system. Furthermore, serial observation of individual patients indicated that infection with cytomegalovirus was associated with a progressive decrease in the L3/L2 ratio.
D000911:Antibodies, Monoclonal / Q000276:immunology; D001853:Bone Marrow / Q000502:physiology; D016026:Bone Marrow Transplantation; D002454:Cell Differentiation; D003586:Cytomegalovirus Infections / Q000276:immunology*; D005802:Genes, MHC Class II; D006684:HLA-DR Antigens; D006801:Humans; D007958:Leukocyte Count; D010641:Phenotype; D012038:Regeneration; D013601:T-Lymphocytes / Q000145:classification / Q000166:cytology* / Q000276:immunology
D000911:Antibodies, Monoclonal; D006684:HLA-DR Antigens