Macrophage heterogeneity in man. A subpopulation of HLA-DR-bearing macrophages required for antigen-induced T cell activation also contains stimulators for autologous-reactive T cells.

Open Access
Publisher Website
Google Scholar
Abstract
Utilizing somatic cell hybridization, a [mouse] monoclonal antibody that interacts only with cells of the [human] monocyte/macrophage (M.vphi.) line and not with other myeloid or lymphoid cells was developed. This antibody detects a 120,000 dalton determinant present on 37 .+-. 2.8% of the peripheral blood M.vphi. from several (HLA-DR)-disparate individuals and only depicts a subpopulation (.apprx. 30%) of HLA-DR-bearing M.vphi. from any single subject. Cytolytic removal of this subpopulation of HLA-DR-bearing cells markedly diminishes antigen-induced T cell reactivity, a deficiency that can be reconstituted with autologous M.vphi. but not with their soluble products containing lymphocyte-activating factor or with intact HLA-DR-disparate M.vphi.. M.vphi. bearing the 120,000 dalton determinant and HLA-DR serve as effective stimulators for autologous mixed lymphocyte reactions; m.vphi. bearing only HLA-DR determinants do not. This latter population of M.vphi. can stimulate proliferation among alloreactive T cells. The Mac-120 [mouse] monoclonal antibody detects a subpopulation of HLA-DR-bearing M.vphi. that is required for the genetically restricted presentation of conventional antigen to reactive T cells. Within the M.vphi. population, these Mac-120+ cells constitute the most effective stimulators for autologous mixed lymphocyte reactions.