title: Frequency of human alloantigen-reactive T lymphocytes. II. Method for limiting dilution analysis of alloantigen-reactive helper T cells in human peripheral blood.
abstract: Quantitative immunologic techniques for analysis of human alloreactivity are currently lacking in transplantation immunology. We report a rapid, sensitive, and quantitative limiting dilution analysis technique that provides a minimal estimate of the number of peripheral blood mononuclear cells (PBMC) capable of secreting interleukin-2 (operationally defined as helpter T lymphocytes) when cultured in vitro with allogeneic PBMC bearing serologically identified MHC disparities. Using this LDA technique, we have estimated that approximately 1/500 to 1/2000 (0.2% to 0.05%) of the PBMC from various individuals can secrete IL-2 after in vitro contact with completely major-histocompatibility-complex-disparate PBMC. Under normal conditions the HTL frequency in human peripheral blood appears quite stable, based on serial analysis of HTL frequency in a healthy human donor. This LDA technique is more rapid and informative than the MLR, and may be useful for pretransplant evaluation and posttransplant monitoring of donor reactivity in transplant recipients.
mesh_terms: D001772:Blood Cell Count / Q000379:methods; D002478:Cells, Cultured; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D007519:Isoantigens / Q000276:immunology / Q000494:pharmacology; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology*
chemical_list: D007376:Interleukin-2; D007519:Isoantigens