SELECTIVE LOSS OF BOLA CLASS-I DETERMINANTS FROM THE LYMPHOCYTE SURFACE AFTER ACID TREATMENT

Acid treatment of bovine lymphocytes by a buffered solution of 0.263 m citric acid and 0.123 M Na2HPO4 at pH = 3.0, originally described for human and marine lymphocytes, selectivity eliminated the antigenicity of MHC (BoLA) class I determinants also from bovine lymphocytes. The viability of acid-treated cell suspension was higher than 90 %. The re activity of acid-treated lymphocytes with BoLA class I typing alloanti scra was lost in microcytotoxicity test, while their reactions with cr oss-reactive anti-HLA class II, anti-BoCD2 and BoCD5 monoclonal antibo dies, and with antisera detecting two non-MHC lymphocyte alloantigenic speciticities. (BoLY wl and R) remained unchanged in the microcytotox icity and/or indirect immunofluorescence tests. The results thus show that this approach of modulating cell surface expression of MFIC class I determinants may be used in cattle.