Macrophage/T‐Lymphocyte Interaction in the Immune Response to PPD in Humans

Abstract

The proliferative response of sensitized human T cells to low concentrations of purified protein derivative of tuberculin (PPD) in vitro has previously been shown lo depend on the presence of autologous or HLA-D-compatible macrophages (M). In this paper we present evidence that the M/T cell interaction requires viable M and docs not involve a soluble factor. T cells from neonates do not respond to PPD in our system, while M) from neonates are able 10 present PPD to T cells from HLA-D matched sensitized adults. It is also demonstrated that the previously reported HLA-D restriction of T cell/M9 cooperation is not due to T cell mediated killing of allogeneic macrophages in vitro.