In vitro Binding Studies of Anti-Human Lymphocyte Globulin: Analysis of Samples Tested for Immunosuppression in the Primate Skin Allograft System.

摘要

Measurements were made of the rates and the quantity of antibody which binds a cultured human lymphoblasts, thymus and, in some cases, Hela cells in 28 anti-human and 2 anti-baboon lymphocyte sera and in 9 normal sera submitted to the National Naval Medical Center for immunosuppressive testing in primates. Further studies of 2 of the 3 non-immunosuppressive ALGs which contained substantial quantities of lymphoblast binding antibodies revealed that one totally lacked antibodies able to bind to human thymus cells. The other contained thymus-reactive antibodies but, in comparison with two ALGs known to be immunosuppressive, it contained much less thymus cell-specific antibody as well as much less antibody cross-reactive with other human cells. All unabsorbed ALGs tested, regardless of immunosuppressive ability, contained more antibodies reactive with Hela cells or lymphoblasts than with thymus cells. Thus, the chief feature which appears to distinguish highly immunosuppressive anti-human ALGs from those with only modest or no ability to prolong graft survival in rhesus monkeys is their content of relatively large quantities of avid antibodies reactive with human thymus cells. These studies demonstrate the ability of this in vitro test not only to rapidly identify ALGs which are likely to be immunosuppressive, but more importantly, to measure directly the relative avidity, specificity, and quantity of their antibodies reactive with lymphoid and non-lymphoid target cells.