Function and distribution pattern of human T lymphocytes. I. Production of anti-T lymphocyte specific sera as estimated by cytotoxicity and elimination of function of lymphocytes.
Antisera were prepared in rabbits against lymphoid cells from peripheral blood of a patient with Bruton-type agammaglobulinaemia. Such antisera could be shown to display a two plateau level of cytotoxicity against human peripheral lymphocytes in the presence of complement. This suggested the presence of species- as well as subgroup-specific antibodies in these antisera. 
 
The subgroup-activity of the antisera could be shown to be directed against human T lymphocytes on the basis of the following results. When lymphocytes are filtered through columns coated with anti-immunoglobulin antibodies lymphocytes with high surface concentrations of immunoglobulin are retained. The filtered cells are highly enriched in cells sensitive to the subgroup-specific antibodies. A close to complete inactivation of mixed leucocyte reactivity or stimulability with soluble PHA was induced by preincubating with the antisera and complement. Using identical conditions only marginal inhibition of immunoglobulin production of peripheral lymphocytes in vitro was induced. 
 
In conclusion, we believe these antisera to selectively kill human T lymphocytes at serum concentrations, which will not kill or inhibit the function of human B lymphocytes.