Aberrant expression of CD27 and soluble CD27 (sCD27) in HIV infection and in AIDS-associated lymphoma

CD27 is a member of the tumor necrosis factor receptor superfamily that is expressed primarily on T cells, as well as on subsets of B cells and NK cel ls. CD70, which is expressed on activated B and T cells, but not on resting lymphocytes, is a ligand for CD27. Cell surface CD27 can be proteolyticall y cleaved to produce a 32-kDa soluble CD27 (sCD27) molecule. Elevated level s of sCD27 are seen in a number of disease states and malignancies. Althoug h it has been reported that cerebrospinal fluid sCD27 levels were elevated in people who had AIDS dementia, little is known about CD27 expression in H IV disease. To determine if sCD27 levels were elevated in those with HIV in fection, and/or in those with AIDS-associated non-Hodgkin's lymphoma (AIDS- NHL), sCD27 levels were measured in HIV-negative and HN-positive subjects a s well as in people who developed AIDS-NHL. Serum sCD27 levels were seen to be elevated in HIV+ subjects. Furthermore, sCD27 levels were particularly elevated in those subjects who went on to develop AIDS-NHL, with serum sCD2 7 levels in AIDS-NHL subjects being significantly higher than those in HIV subjects who did not develop lymphoma. Most AIDS-NHL cell lines and primar y ALDS-NHL tumor specimens expressed both CD27 and its ligand, CD70. The pr oportion of circulating B cells that expressed cell surface CD27 was substa ntially reduced in those with HIV infection, and B cells from HIV-infected subjects produced decreased levels of sCD27 in culture. Together, these res ults indicate that CD27/sCD27 expression is abnormal in HIV infection and s uggest that this molecule merits further examination as a potential marker for AIDS-NHL, (C) 1999 Academic Press.