Hapten-specific T-cell unresponsiveness induced bybenzylpenicilloyl autologous gamma globulin conjugates in human lymphocyes in vitro

Oligonucleotide linked to human gammaglobulin specifically diminishes anti-DNA antibody formation in cultured lymphoid cells from patients with systemic lupus erythematosus

In vitro studies were undertaken to determine whether the level of anti-DNA antibody can be modulated in humans with systemic lupus erythematosus (SLE). DNA fragments of different sizes, i.e., oligonucleotide (N20-30) or oligonucleotide (N10-100), were covalently linked either to human gammaglobulin (HGG) and used as tolerogens or to keyhole limpet hemocyanin and used as immunogens. Experiments were done to determine whether such tolerogens specifically diminish antibodies to denatured DNA, native DNA, or both. PBL were obtained from 87 patients with SLE, 55 of whom spontaneously produced anti-DNA antibodies in vitro. Furthermore, of these 55 test subjects 23 made anti-DNA antibodies in response to antigen challenge in vitro. Exposure of PBL to tolerogenic oligonucleotide-HGG reduced spontaneous antibody formation in 34 of the 55 patients' PBL and abrogated the in vitro-induced response in all instances. The suppression was tolerogen specific. In some SLE patients lymphoid cells were suppressed by both (N10-100)-HGG and (N20-30)-HGG, while in others lymphoid cells were suppressed by only one. Longitudinal studies of spontaneous antibody production showed that the same tolerogens consistently reduced anti-DNA antibody formation in lymphoid cells of 12 patients on several occasions over a 2-yr interval, but in 8 others the results were either variable or inconsistent. In contrast, tolerogens consistently abrogated the antigen-induced response in all 23 patients' PBL. These results obtained in humans in vitro suggest that the principle of carrier-determined tolerance could be applied as a specific therapy for SLE in vivo.

Hapten-specific carrier-dependent tolerance induction in man in vitro

We sought to determine whether hapten-specific tolerance can be induced in cultured human lymphocytes in vitro. Unfractionated as well as T and B cells from peripheral blood lymphocytes of healthy human volunteers were cultured with different hapten-carrier conjugates before in vitro challenge with dinitrophenyl (DNP) linked to keyhole limpet hemocyanin. Hapten-specific antibody was detected in the supernatant by solid-phase radioimmunoassay. Both hapten specificity and carrier dependence in addition to the cellular basis of tolerance induction were examined. The results show that hapten-specific tolerance of antibody production was induced by human gamma-globulin (HGG) conjugated to DNP but not by other conjugates of DNP nonhuman gamma-globulin, as well as human serum albumin. Moreover, both T and B cells are involved in tolerance induction to DNP-HGG in vitro. The significance of tolerance in human in vitro for the specific therapy of autoimmune disease is discussed.