IgG subclass response to HIV in relation to antibody-dependent cellular cytotoxicity at different clinical stages.
The anti-HIV IgG subclass response was analysed in sera from different clinical stages and related to virus specific antibody-dependent cellular cytotoxicity (ADCC). IgG1 was found to be the dominant subclass, present in all sera and with similar mean titres at different stages. The number of anti-HIV IgG3 positive sera, measured on whole viral lysate antigen plates, decreased during disease progression from 38% in symptom-free to 7% in AIDS patients. IgG2 and IgG4 subclasses were less prevalent although a slight increase of IgG4 frequency was found in AIDS patients. High IgG1 titres correlated with a positive ADCC reaction but there was no correlation between anti-HIV IgG1 and ADCC titres. Some sera which contained HIV IgG1 as the only subclass were able to mediate an ADCC reaction. In addition, when anti-HIV IgG3 was isolated, by protein A chromatography, no ADCC killing was induced by these antibodies. It is concluded that IgG1 is the major ADCC-active IgG subclass in HIV infected individuals. The lack of correlation between IgG1 and ADCC titres may be explained by a relatively small fraction of IgG1 antibodies mediating ADCC.
Ljunggren
K
K
Department of Immunology, Karolinska Institute, Stockholm, Sweden.
Broliden
P A
PA
Morfeldt-Månson
L
L
Jondal
M
M
Wahren
B
B
D000386:AIDS-Related Complex / Q000276:immunology; D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology*; D000920:Antibody-Dependent Cell Cytotoxicity; D015483:HIV Antibodies / Q000032:analysis / Q000145:classification*; D006679:HIV Seropositivity / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000145:classification*
D015483:HIV Antibodies; D007074:Immunoglobulin G