title: PHA stimulation of separated human lymphocyte populations.
abstract: Lymphocyte preparations from peripheral blood and tonsils were separated into populations enriched with T or B cells by formation of rosettes with SRBC and separation of the rosette-forming and non-rosette-forming populations. T cell-enriched populations were also prepared by nylon column filtration. Using these methods preparations were obtained which comprised 80--95% T or B lymphocytes as determined by E-rosette formation and surface immunoglobulin (Ig) staining. PHA responsiveness, measured by [3H]thymidine incorporation, varied between relatively wide limits and was critically dependent on the degree of separation obtained. Relatively pure B-cell populations (less than 12% T cells) from blood and tonsils gave low PHA responses while preparations from blood still containing 24--38% T cells gave responses equal to or even greater than those of unseparated controls (60--78% T cells). T cell-enriched populations (80--86% T cells) responded to an equal or greater degree than controls but more efficient separation (greater than 90% T cells) resulted in markedly reduced stimulation. There was thus no simple correlation between the degree of phytomitogen-induced transformation and the number of T cells present. It is concluded that the low response of relatively pure T-cell populations may be due to depletion of B cells or non-lymphoid cells (or both) during the separation procedures. These observations have implications for the use of PHA stimulation as a measure of T-cell activity in mixed populations such as those of human peripheral blood leucocytes.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D002469:Cell Separation; D005455:Fluorescent Antibody Technique; D006801:Humans; D007104:Immune Adherence Reaction; D037102:Lectins / Q000494:pharmacology*; D008213:Lymphocyte Activation; D009757:Nylons; D014066:Palatine Tonsil / Q000166:cytology; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D037102:Lectins; D009757:Nylons; D011947:Receptors, Antigen, B-Cell