INFILTRATING GAMMA-DELTA T-CELLS AND SELECTIN ENDOTHELIAL LIGANDS IN THE CUTANEOUS PHYTOHEMAGGLUTININ-INDUCED INFLAMMATORY REACTION

The 24 h phytohaemagglutinin-induced skin inflammatory site (intraderm al and subcutaneous) was studied in inbred MHC-homozygous (SLAb/b) pig s and it was found, by immunohistology, that the predominant lymphocyt es in the infiltrate are CD2(-)CD4(-)CD8(-)sIg(-) T-cells, the Null/ga mma delta T-cell family, identified using the monoclonal antibodies (m Abs) MAC320 and MAC319 (which recognises a subset of MAC320(+) cells). A large percentage of the infiltrating cells expressed the ya T-cell receptor phenotype identified by binding of the mAb 86D. Fewer CD2(+), CD8(+) and CD4(+) cells were present and surface immunoglobulin posit ive (sIg(+)) cells were virtually absent in the infiltrate. Areas of l ymphocytic infiltration were associated with endothelial activation as determined by expression of the E-selectin and a ligand for the L-sel ectin.