1986 Volume 9 Issue 6 Pages 484-494
Monoclonal antibody Sa 3 was obtained by fusion of spleen cells from the BALB/c mice immunized with Epstein-Barr virus (EBV) transformed human B lymphoblastoid cell line, EBV-SA (HLA-A 24, B 7, C-, DR 1, DQ 1, DP 4) to mouse myeloma P 3-NSI/1-Ag 4-I (NS-1) cells. In the microcytotoxicity test, enzyme linked immunosorbant assay (ELISA) and immunofluorescence technique, this antibody reacted with EBV-transformed B lymphoblastoid cell line, Burkitt's lymphomas, Pre-B leukemia and peripheral B cells, but not with T cell leukemias, Myeloid leukemia or peripheral T cells. The immunoglobulin class of this antibody, which was designated as Sa 3, was IgG3. Two-dimensional gel electrophoresis analysis showed that Sa 3 could detect the HLA class II antigens including DR, DQ and DP on the cell surface of EBV-transformed B lymphoblastoid cell lines. In reactivity of Sa 3 against transfected cells, it became clear that Sa 3 could recognize the HLA-DQ and DP antigens expressed on T cell leukemia (CEM) transfected with the cloned DQα and DQβ or DPα and DPβ genes. On the other hand, it was demonstrated that Sa 3 have inhibitory effects on the mixed lymphocyte reaction (MLR) and Pokeweed mitogen (PWM)-induced immunoglobulin synthesis.
In our experiment, since Sa3 could detect the HLA class II (DR, DQ and DP) antigens, this antibody will be quite useful to analyze human immune regulations at the cellular level.