Evidence that initial T cell depletion suppresses antiantibody formation and preserves immunosuppression after polyclonal ATG

The authors have demonstrated that T lymphocytes in fact initiate sensitization to ATG, resulting in a complete blockage of its immunosuppressive effect. The decisive role of T cells in antiantibody formation to ALG, which is not apparent in mice rendered T-lymphopenic by heterologous ALG, became evident in a mouse model in which murine antibodies induced T cell depletion. The authors show that in mice, T lymphopenia induced by murine anti-Thy-1 mAb suppresses subsequent sensitization to ALG. Their observation that T lymphopenia induced by autologous anti-Thy-1 mAb can suppress the immune response to polyclonal heterologous antibodies may lead to an understanding of the mechanism of sensitization to cell-binding antibodies and indicate methods for circumventing antiantibody formation.