Increased expression of CD40 ligand on activated T cells of patients with colon cancer.

Abstract

Proper function of T lymphocytes is crucial for an effective destruction of cancer cells in vivo. Identifying the cell surface molecules on the T cells that may be involved in this antitumor response may help to elucidate immunological factors influencing the biology of human tumors. Differences in the antigen expression profile of unstimulated and stimulated peripheral blood T-lymphocytes from patients with colon cancer and from normal controls were determined using flow cytometry. Freshly isolated peripheral blood T cells of patients with colon cancer did not differ in their phenotype significantly from those of patients with nonmalignant diseases. In contrast, in vitro stimulated T cells of patients with colon cancer had a significantly increased expression of CD40 ligand (CD40L, CD154) compared with activated T cells of the control group; increased CD40L expression was also found in the CD4(+)- and CD8(+)-T-cell subpopulations. The data presented support additional studies investigating the role of CD40L in the immune response against colon carcinoma.