Selective distribution and quantitation of T-lymphocyte subsets in germinal centers of human tonsils. Definition by use of monoclonal antibodies.

The distribution and quantitation of T-lymphocyte subpopulations of human tonsils were studied in situ by the avidinbiotin-peroxidase technique, using monoclonal antibodies to total, helper, and suppressor T cells. Primary follicles contained few T lymphocytes. The germinal centers of secondary follicles contained numerous T cells: in the periphery, 14.2% +/- 1.7% (mean +/- SD), and in the central area, 2.4% +/- 0.7%, of follicular lymphocytes counted were T lymphocytes. The mantle zone had fewer T lymphocytes (7% +/- 0.9%). Most of the T lymphocytes found in the germinal centers had the helper-cell phenotype. There were fewer than 1% of suppressor T lymphocytes in the germinal centers. An occasional secondary follicle could contain up to 10% of suppressor cells (range, 0% to 9.7%). The interfollicular areas contained preponderantly T lymphocytes, a majority of which reacted with monoclonal antibodies to helper cells. The distribution and enumeration of T lymphocytes in normal reactive lymphoid tissue provide a basis for studies of pathological specimens.