title: Loss of CD45R and gain of UCHL1 reactivity is a feature of primed T cells.
abstract: A group of mAb recognizing the 200- and/or 220-kDa determinants (CD45R) of the leukocyte common Ag such as 2H4, WR16, MD4.3, and SN130 cross-block each other showing that they recognize a closely related epitope. The antibody UCHL1 reacts with a 180-kDa determinant of the leukocyte common Ag and exhibits a reciprocal T subset distribution pattern to the CD45R group. Peripheral blood T cells were 40% positive for UCHL1 and 58 to 65% positive for the CD45R antibodies; less than 1% of cells stained for both. On activation of CD45R+,UCHL1- T cells by PHA, up to 40% of cells became positive for both CD45R and UCHL1 by day 3. By day 7, CD45R+,UCHL1- cells fell from 90 to less than 21% whereas UCHL1+,CD45R- cells rose from 2 to 93%. Conversely, PHA-stimulated UCHL1+,CD45R- cells remained UCHL1+,CD45R- during the 7 days in culture showing that phenotypic change was unidirectional from CD45R+ to UCHL1+. In primary allogeneic mixed lymphocyte reactions, activated CD45R+ T cells also showed a change to UCHL1+. When these cells were rechallenged by the original alloantigen, the UCHL1+ cells showed 7- to 20-fold greater proliferation than the CD45R+ cells on day 3 after rechallenge. The recovery of virtually all alloantigen induced secondary proliferative response in the UCHL1+,CD45R- T cell population suggests that UCHL1 identifies a primed population of T cells which may include memory cells.
authors.affiliation: Department of Immunology, Royal Free Hospital School of Medicine, London, United Kingdom.
authors.forename: A N
authors.initials: AN
authors.lastname: Akbar
authors.forename: L
authors.initials: L
authors.lastname: Terry
authors.forename: A
authors.initials: A
authors.lastname: Timms
authors.forename: P C
authors.initials: PC
authors.lastname: Beverley
authors.forename: G
authors.initials: G
authors.lastname: Janossy
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis / Q000502:physiology*; D000937:Antigen-Antibody Reactions; D000943:Antigens, Differentiation / Q000032:analysis* / Q000276:immunology; D001666:Binding Sites, Antibody; D002469:Cell Separation; D003429:Cross Reactions; D006649:Histocompatibility Antigens / Q000032:analysis* / Q000276:immunology; D006801:Humans; D007399:Interphase; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed / Q000379:methods; D010641:Phenotype; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D006649:Histocompatibility Antigens; D010835:Phytohemagglutinins; D017493:Leukocyte Common Antigens