Lymphocyte subsets and activation antigens in a reference population: a flow cytometric study using single and double...

The transferrin receptor (TR), the HLA DR antigen (DR), and the antigen binding OKT10 (T10) are present on activated lymphocyte populations. The authors have studied their expression and that of antigens defined by eight commercial monoclonal antibodies on peripheral blood lymphocytes of 50 healthy hospital workers aged 23-60 years. A whole blood lysis technique was employed and cells were enumerated on a flow cytometer. The percentage of cells bearing the three activation antigens were generally low: mean values for T10 being 7.2%; for TR 1.8%; and for DR 8.8%. There was, however, considerable variability, with occasional subjects having 20% or more cells positive for one of the three antigens. High values of one activation antigen did not correspond with high values of another in the same subject. Nor was there correlation of the presence of activation antigens with the occurrence of cells bearing T11, T4, T8, Leu 1, Leu 2a, Leu 3a, or Leu 7. Double labelling with the following pairs of fluorescein (FITC) and phycoerythrin (PE) labeled antibodies: Leu 2a, DR; Leu 3a, DR; Leu 3a, Leu 2a; TR, DR, indicated that simultaneous expression of the corresponding antigens do not normally occur on lymphocytes of healthy individuals. Double labelling with B1 and DR in five subjects indicated the presence of B1 (+) DR (-) cell population. No pattern of relationship could be detected among common clinical variables or HLA type and an increased expression of activation antigens.