Effect of complement inactivated rabbit antichick brain serum on thymic and splenic lymphocytes

The effects on in vitro exposure of chicken thymic-dependent lymphocytes to complement inactivated rabbit antichick brain serum (RACB) previously absorbed with normal serum (ns) and kidney (k) [RACBns,k] was investigated. Spleen lymphocytes which normally initiate a 'graft vs. host' reaction give rise to much more intense reactions when treated with (RACB)ns,k. This may be due to increased antigenicity of the donor cell and/or stimulation of the donor T cell. Migration studies showed that chicken thymocytes are capable of in vitro migration which can be inhibited by exposure to (RACB)ns,k. Thymocytes pretreated with (RACB)ns,k were found to express factor(s) capable of inhibiting thymocyte migration. The correlation between lymphokines and increased splenomegaly was discussed.