Human lymphocyte subpopulations study of T and B cells and their density distribution

The proportions of T and B cells of various human lymphoid tissues were enumerated by sheep red blood cell and sensitized sheep red blood cells + complement rosettes. Methods using optimal temperature and time of incubation, which yielded the maximum proportion of rosettes, were used. The proportion of T cells in human peripheral blood, tonsils, spleen, thymus, and thoracic duct lymph were 72.5, 42.0, 29.3, 94.0, and 54.2%. The variations in the blood of three individuals were also studied over a period of 3–6 months. Density profiles of these tissues were analyzed by discontinuous Ficoll density gradient. The density profiles of these tissues were very similar. T and B cells were enumerated in the various fractions of the gradient. Both types were present in all the fractions analyzed, but the B cells predominate in the light density fractions, while the T cells in the heavy density fractions.