title: Limiting dilution analysis of proliferative responses in human lymphocyte populations defined by the monoclonal antibody UCHL1: implications for differential CD45 expression in T cell memory formation.
abstract: Using limiting dilution analysis, we investigated proliferative responses of UCHL1+ and UCHL1- T cell populations to compare the precursor cell frequencies following recall and alloantigen stimulation, and the complexity of cellular interactions within UCHL1+ and UCHL1- populations. We find high frequencies of recall antigen responses among UCHL1+, but not UCHL1- T cells. In contrast, both populations contain similar frequencies of alloantigen responsive cells. Our results are consistent with single-hit kinetics in recall as well as alloantigen responses and show no complex cellular interactions within the responding populations. In conclusion, the difference between the recall antigen response of UCHL1+ and UCHL1- cells observed in conventional proliferation assays is most probably due to a high frequency of recall antigen-responsive UCHL1+ cells and not to suppressive phenomena in the UCHL1- population. These data suggest that memory T cells are largely of the UCHL1+ phenotype. The relation of post-thymic T cell maturation and differential CD45 expression is briefly discussed.
authors.affiliation: ICRF Human Tumour Immunology Group, University College and Middlesex School of Medicine, London, GB.
authors.forename: M
authors.initials: M
authors.lastname: Merkenschlager
authors.forename: L
authors.initials: L
authors.lastname: Terry
authors.forename: R
authors.initials: R
authors.lastname: Edwards
authors.forename: P C
authors.initials: PC
authors.lastname: Beverley
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000943:Antigens, Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D006649:Histocompatibility Antigens / Q000502:physiology*; D006801:Humans; D007156:Immunologic Memory; D066298:In Vitro Techniques; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D006649:Histocompatibility Antigens; D017493:Leukocyte Common Antigens