ABSTRACT
In most suppressor T-cell-mediated phenomenon studied so far in the chicken, the suppressor cells appear to be CT8 + CT4 -. This chapter demonstrates the presence of both antigen-specific helper and suppressor T cells in both normal and A+¦ chickens after a single i.v. antigen injection. The effect of cimetidine, type II histamine receptors (H2R) antagonist, on suppression of the secondary anti- sheep red blood cell (SRBC) response, induced by addition of antigen on day 0 of culture, was also investigated. Transfer of bovine serum albumin (BSA)-tolerant spleen cells without or with specifically primed adult spleen cells into normal recipients, followed by BSA challenge, prevented any significant primary or secondary anti-BSA response. The suppression was antigen specific, since BSA-tolerant spleen cells were unable to suppress either primary or secondary responses of B cells to SRBC. Since suppressor cells could not be demonstrated, the T-cell tolerance in these chickens appeared to be primarily due to deletion of antigen-responsive cells.
