Selection on the Basis of Major Histocompatibility Type of Lymphoid Cells From a Bovine Chimaera Transformed by Theileria Parasites

In an investigation of the expression of major histocompatibility complex (M.H.C.) antigens by cells infected and transformed in vitro by Theileria parasites, Spooner and Brown (1980) reported that the qualitative expression of such antigens remained unaltered by infection and transformation. However, in one instance cells taken from a dizygous twin and transformed by Theileria parva (Muguga) were found to have a different pattern of reactivity with the Edinburgh panel of Bovine Lymphocyte Antigen (BoLA) typing sera from those of the fresh peripheral blood lymphocytes (PBL) from the donor. Conversely PBL from the same animal transformed by T. annulata (Hissar) exhibited the same BoLA phenotype as uninfected PBL. The donor was a chimaera and it was suggested that the T. parva (Muguga) cell line arose from cells of a minor population within the chimaera, the inference being that this minor population was too small to be detectable in the standard BoLA-typing test. The results of BoLA typing of the parents of the cell donor were consistent with this hypothesis.