A CTL assay requiring only 150 mu 1 of mouse blood

In this paper, we present a method for measuring antigen specific cytotoxic T lymphocyte (CTL) activity from individual mouse peripheral blood samples without animal sacrifice. Peripheral blood cells are stimulated in vitro w ith a cocktail of antigen, cytokines, costimulatory molecules and irradiate d feeder cells resulting, 7 days later, in a readily detectable antigen spe cific signal from a well plated under limiting dilution conditions. This hi ghly sensitive and antigen specific assay is more efficient than convention al CTL assays and thus increases the number of mice that can be tested in a single assay. Since blood samples can be assayed from an individual mouse at multiple times during the course of an in vivo study, the assay can faci litate and strengthen correlative studies on CTL responses and in vivo resu lts. (C) 2000 Elsevier Science B.V. All rights reserved.