title: The early (18-hr) human mixed lymphocyte reaction: identification and isolation of activated T-cell clones.
abstract: This study provides direct evidence that de novo expression of the activation antigens B1 49.9 (49.9) (interleukin-2 receptor) and 4F2 enables identification of alloactivated cells within 18 hr of initiation of human mixed lymphocyte reactions (MLR). Using a dual-parameter flow cytometer (simultaneous assessment of immunofluorescence and DNA content on the same cell), it was demonstrated that these activation antigens emerge before activated cells enter into S/G2/M phase of the cell cycle. Family studies illustrate that early activation antigen appearance occurs in response to a mismatch at chromosome 6, and invariably heralds the proliferative outcome at 6 days of MLR. In order to directly study the small alloactivated T-cell population, 49.9-positive cells were isolated using a cell sorter after 18 hr of MLR and cloned by limiting dilution using purified recombinant interleukin-2 (rIL-2). Antigen-specific T4-positive T-cell clones were isolated. Analysis of these clones demonstrates that antigen-specific reactivity is acquired within 18 hr in the MLR. These methods should permit a dissection of the early events of alloactivation.
authors.forename: A A
authors.initials: AA
authors.lastname: Ythier
authors.forename: J M
authors.initials: JM
authors.lastname: Williams
authors.forename: H M
authors.initials: HM
authors.lastname: Shapiro
authors.forename: V E
authors.initials: VE
authors.lastname: Kelley
authors.forename: T B
authors.initials: TB
authors.lastname: Strom
mesh_terms: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000032:analysis; D002469:Cell Separation; D002999:Clone Cells / Q000166:cytology / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D007519:Isoantigens / Q000032:analysis; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008938:Mitosis; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D013997:Time Factors; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007519:Isoantigens; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7