GM3 as a target of anti-lymphocytic ganglioside antibodies in AIDS patients.

IgG antibodies reacting with the GM3-comigrating band extracted from pooled AIDS lymphocytes were detected in 33.3% of AIDS patients sera, in 8% of asymptomatic anti-HIV-positive subjects, in none of the sera obtained from asymptomatic anti-HIV-negative drug abusers, from patients with acute B and chronic C hepatitis, and from healthy donors. All positive sera reacted selectively with the GM3-comigrating band obtained from AIDS lymphocytes but not with the corresponding band from normal lymphocytes. The lymphocytic ganglioside autoantigen was revealed as GM3. In addition, two main data were shown: (a) AIDS lymphocytes have an increased concentration of GM3 and (b) the ceramide of AIDS lymphocytic GM3 has a different percentual composition of fatty acids in contrast to control cells. It is suggested that these quantitative and qualitative changes might be responsible for the appearance of circulating anti-lymphocytic GM3 antibodies.