Infiltrating gamma delta T-cells and selectin endothelial ligands in the cutaneous phytohaemagglutinin-induced inflammatory reaction.

The 24 h phytohaemagglutinin-induced skin inflammatory site (intradermal and subcutaneous) was studied in inbred MHC-homozygous (SLAb/b) pigs and it was found, by immunohistology, that the predominant lymphocytes in the infiltrate are CD2-CD4-CD8-sIg-T-cells, the Null/gamma delta T-cell family, identified using the monoclonal antibodies (mAbs) MAC320 and MAC319 (which recognises a subset of MAC320+ cells). A large percentage of the infiltrating cells expressed the gamma delta T-cell receptor phenotype identified by binding of the mAb 86D. Fewer CD2+, CD8+ and CD4+ cells were present and surface immunoglobulin positive (sIg+) cells were virtually absent in the infiltrate. Areas of lymphocytic infiltration were associated with endothelial activation as determined by expression of the E-selectin and a ligand for the L-selectin.