Monoclonal antibodies putatively recognising activation and differentiation antigens.

In the activation/maturation section, 46 monoclonal antibodies (mAbs) were analysed using freshly isolated as well as mitogen activated and recall antigen re-stimulated cells. A total of 10 internal standards as well as 6 antibodies with established reactivity for human cells, reported to cross-react with porcine leukocytes, were included in the panel. The standard antibodies were anti-CD25, CD44, CD45, SLA II, SWC1, SWC2, SWC7 and SWC8 reagents. The test panel contained antibodies with putative reactivity to CD25, SLA II and other mAbs directed against ill-defined targets. Single and double colour surface staining was performed in the attempt to group the mAbs tested into clusters of differentiation. Five new anti-class II reagents, two directed to SLA-DQ and three to SLA-DR, could be added to the previously established ones. One new anti-CD25 as well as two new antibodies with SWC7 and SWC8 specificities, respectively, could also be added to the previously established ones. The identity of the two latter antibodies was also confirmed in other sections of this workshop (B-cell section for SWC7 antibodies and myeloid section for the SWC8 antibodies). The antibody JM2F12, in our hands, has shown strong similarities to the cross-reactive anti human-CD49f reagent. No other clusters were identified, as all remaining antibodies behaved in a different way on different target leukocyte populations. The second purpose of the section was fulfilled: interesting staining profiles of several antibodies on differentiating lymphocytes were recorded and are discussed here.