HTLV and immunosuppression

Abstract

There is increasing evidence for the link between members of the human T-lymphotropic virus family and clinically important disease. We used indirect membrane immunofluorescence (IMI) to screen patient and control sera for antibodies to human T-cell leukemia virus (HTLV) specific cell membrane antigens (HTLV-MA) of HTLV-I and HTLV-III. Representative sera were screened for antibodies to specific HTLV-encoded proteins using radioimmunoprecipitation (RIP) with SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Essentially all Japanese patients with adult T-cell leukemia/lymphoma (ATLL) from Miyazaki, Japan had detectable antibodies to HTLV-I-MA, further supporting the evidence for the probable etiologic relationship of HTLV-I and ATLL. While 16% of the healthy adults from this endemic region had antibodies to HTLV-I-MA, such antibodies were also found in 42% of the adults hospitalized in Miyazaki with severe infections diseases. Other studies have demonstrated HTLV-I antibodies in 12% of asymptomatic hemophiliacs examined from various U.S. cities. We have previously shown that HTLV-I status positive antibody in hemophiliacs is accompanied by a decrease in the number of T helper cells. Patients seropositive for antibodies to HTLV-I-MA regularly demonstrated antibodies to the env gene encoded gp61 proteins, while lower but significant proportions had antibodies to the gag and lor gene proteins. These and other observations suggest that infection with at least some strains of HTLV-I may be associated with mild or transient immunosuppression, in the absence of leukemia. Analysis by RIP indicated that gp61 and gp45, both encoded by the env gene of HTLV-I, are the most immunogenic proteins of the virus. The gp61 HTLV-I is highly crossreactive with gp67, the major env protein of HTLV-II. Patients with acquired immune deficiency syndrome (AIDS) were also examined for antibodies to HTLV-I-MA and antibodies to the gag, env, and lor gene proteins by RIP. Antibodies were detected in 38-75% of the patients, the higher percentage reflecting the presence of at least one positive sample in those individuals where more than three serial serum samples were tested. Numerous control groups were essentially seronegative for antibodies to HTLV-I proteins. When AIDS patient sera were examined for antibodies to HTLV-III, 95-100% were seropositive. Such antibodies were also found in the majority of asymptomatic Boston-areas hemophiliacs.(ABSTRACT TRUNCATED AT 400 WORDS)