In vitro production of anti-HLA-DR antibodies by human B-cell lines.

Human B-cell lines secreting antibodies which react preferentially with the HLA Class II antigen DR5 have been produced. Supernatants from these cell lines reacted with lymphocytes from all DR5 positive donors and a minority of DR6 positive donors but were negative on lymphocytes of other phenotypes. The cytotoxic activities of the supernatants apparently depend on IgM antibody. These results demonstrate the potential of B-cell lines for the in vitro production of antibodies to HLA-DR antigens.

HLA typing of Epstein-Barr virus transformed lymphoblastoid cell lines (LCL).

The application of standard tissue typing techniques to cells other than peripheral blood lymphocytes has been accompanied by the problem of extra reactions. This applies as well to Epstein-Barr virus transformed lymphoblastoid cell lines (LCL) as to leukemic cells and human spleen cells. These extra reactions are attributable to additional antibodies in the typing sera which are not apparent under standard conditions with PBLs. Two types are described: Type 1 extras, which becomes apparent after longer incubation times and are attributed to weak antibodies and type 2 extras which are apparent after shorter incubation times and are attributed to subpopulation specific or differentiation antigens. Technical modifications are proposed by which these extras can be circumvented. They include: Only start typing when cells have been cultured for 2 to 3 days. Remove dead cells by spinning over standard ficoll-hypaque or 11% triosil. Use shorter incubation times. Avoid using sera that give too many type 2 extras. In this way phenotypes can be accurately identified on LCL's obtained from kidney transplant donors and recipients. When LCL's were compared with their matching PBL, HLA phenotypes were concordant in 87% of cases for HLA-A, 90% for HLA-B, 81% for HLA-C and 70% for HLA-DR.