Expression of T3 and T11 determinants on human peripheral lymphocytes as analysed by the indirect antiglobulin rosetting reaction (IARR) and indirect immunofluorescence.

Whereas by indirect immunofluorescence approximately 80% of freshly isolated human peripheral blood lymphocytes bound T3 (Leu 4)-specific and T11-specific monoclonal antibodies, by a more sensitive technique--the indirect antiglobulin rosetting reaction--more than 90% of these lymphocytes were T3+ (Leu 4+) and T11+; this finding suggested that some non-T cells may also express T3 and T11 determinants. In double labelling experiments most normal surface membrane immunoglobulin (smIg)-bearing lymphocytes, ie, B cells, were shown to express T3 and T11 determinants at low density. The determinants were re-expressed after stripping with trypsin. Moreover, greater than 90% of neoplastic lymphoid cells expressing monotypic smIg from six donors were T3+ and/or T11+. Together these results provide new data on the cell distribution of 'T cell markers'. These findings also indicate that the rosette test is too sensitive to distinguish between biologically distinct lymphocyte population, ie between T and B cells.