Development of Primary γM, γG, and γA Anti-TNP Plaque-Forming Cell Responses in Vitro

Abstract

Abstract Trinitrophenylated bacteriophage φX174 (TNP-φX) is a potent in vitro immunogen capable of stimulating specific anti-TNP plaque-forming cell (PFC) responses in cultures of mouse spleen cells. Under optimal conditions, 10 × 106 spleen cells and 3 × 109 TNP-φX particles in 1 ml of culture medium, TNP-specific PFC responses representing the major mouse immunoglobulin classes, γM, γ1, γ2, and γA were detected. A study of kinetics of appearance of these immunoglobulin class-specific PFC revealed that an increase in γM PFC was detected within 24 hr of initiation of the cultures; the maximum γM PFC responses were on days 4 and 5. γ1 and γ2 PFC were not detectable until day 3 of culture and reached maxima on days 5 and 6. The anti-TNP PFC response to TNP-φX was almost completely suppressed by the addition of 100 µg TNP guinea pig albumin; the addition of free φX at a 10-fold excess over the TNP-φX immunogen suppressed the anti-TNP response about 70%.