Cellular interactions in marrow-grafted patients. II. Normal monocyte antigen-presenting and defective T-cell-proliferative functions early after grafting and during chronic graft-versus-host disease.

The proliferation of T cells of marrow donor origin in response to Escherichia coli, an ubiquitous antigen, presented by circulating monocytes of marrow donor origin was investigated in 30 human allogeneic marrow transplant recipients. Compared with cells from healthy marrow donors, T cell proliferation was found to be deficient in all recipients studied 36-71 days after grafting, regardless of the presence or absence of acute graft-versus-host disease and in most patients with chronic graft-versus-host disease studied 118-1804 days postgrafting . In contrast, lymphocytes from most long-term patients without chronic graft-versus-host disease studied 363-2673 days had immune reactivity comparable to that of lymphocytes from their marrow donors. Results of cell-mixing experiments showed that (1) monocytes from most marrow recipients were capable of presenting antigens to normal T cells of marrow donors, and (2) T cells from short-term patients and from long-term patients with active chronic graft-versus-host disease were not induced to proliferate by E-coli-pulsed monocytes from the marrow donors. This inability of T cells to proliferate was likely the result of ineffective interactions among T cell subsets.