EFFECT OF PERMEABILIZATION ON PERIPHERAL-BLOOD LYMPHOCYTES OF BOVINE LEUKEMIA-VIRUS (BLV)-INFECTED CATTLE

Cell surface proteins serve as markers for immunophenotypic characteri zation of lymphocyte subsets by appropriate monoclonal antibodies and fluorescence-activated cell sorter (FAGS) analysis. By the same method , internal antigens or those that are only partially expressed on the cell surface can be determined after permeabilization of the cells. Pe ripheral blood lymphocytes obtained from bovine leukemia virus (BLV)-i nfected cattle and from BLV-free cattle were permeabilized and several lymphocyte populations were examined. BoCD4, BoCD8 and three CD4(-) C D8(-)T-cell subsets retained their original frequencies after permeabi lization in both groups of animals. The recognition of the B-B2 lympho cyte molecule was only partially expressed on the cell surface of inta ct lymphocytes and was further revealed on permeabilization. The frequ ency of permeabilized, but not intact, cells stained with this mAb was significantly higher for BLV-infected cattle than for BLV-free animal s (P = 0.006). Reactivities of an anti-heat shock protein (Hsp) 70 wer e measured before and after permeabilization of PBLs. Similar increase d cell frequencies were obtained for both groups of bovines. These dat a indicate that flow cytometry studies should be conducted on both per meabilized and intact cells for a better assessment of protein express ion on the cell surface, as well as in the cytoplasm. (C) 1997 Elsevie r Science B.V.