Analysis of monoclonal antibodies reacting with molecules expressed on γδ T-cells

Twenty-six monoclonal antibodies (mAbs) selected after the first round of analysis in the Third International Swine Workshop were grouped with additional mAbs from the first and second workshops and mAbs under study for further evaluation. Preparations of peripheral blood leukocytes were used in single and multicolor flow cytometric (FC) analyses. Six mAbs did not react with γδ T-cells. Two were negative for all tested specificities. Seven mAbs recognized molecules expressed on γδ T-cells that were not lineage restricted. One of these from the first workshop (2B11) yielded a pattern of labeling identical to a mAb under study (PGB73A). Ten mAbs were characterized in previous workshops and known to react with the γδ TCR or molecules expressed on subsets of γδ T-cells. One belonged to SWC4, two to SWC5, and one to SWC6. Two mAbs from the second workshop recognized a molecule or molecules expressed on subsets of γδ T-cells. A new mAb (PPT16) added late to the workshop following a request by the workshop chairs appeared to recognize a determinant expressed on the γδ TCR/CD3 molecular complex.