Increased levels of galactose-deficient IgG in sera of HIV-1-infected individuals.
BACKGROUND
The IgG from sera of patients with chronic inflammatory diseases of autoimmune character or some chronic microbial infections is frequently deficient in galactose on N-linked glycans. However, this phenomenon has not been investigated at length in human viral infections.


OBJECTIVE
To evaluate the glycosylation of serum IgG in HIV-1-positive patients.


METHODS
Psathyrella velutina lectin was used in enzyme-linked immunosorbent and Western blot assays to determine glycosylation. In addition, gas-liquid chromatography and mass spectrometry were utilized to confirm the galactose deficiency observed in the lectin-binding assays.


RESULTS
HIV-1-infected individuals had significantly higher levels of galactose-deficient IgG than healthy controls. In fact, the galactose deficiency of the N-linked glycans observed in other diseases was even more profound in HIV-1 infection. This deficiency was primarily restricted to IgG when total serum glycoproteins were evaluated and IgG1 was the subclass most affected in all patients. Also, a significant increase in lectin binding was observed on IgG2 and IgG4 from HIV-1-positive females compared with HIV-1-negative females.


CONCLUSIONS
Identification of deficient galactosylation of serum IgG from HIV-1-infected patients extended the spectrum of diseases in which this phenomenon has been observed. In addition, the results suggest yet another aspect of immune dysfunction as a result of HIV-1 infection.
Moore
Jennifer S
JS
Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA. moorejs@uab.edu
Wu
Xueling
X
Kulhavy
Rose
R
Tomana
Milan
M
Novak
Jan
J
Moldoveanu
Zina
Z
Brown
Rhubell
R
Goepfert
Paul A
PA
Mestecky
Jiri
J
D000328:Adult; D000363:Agaricales; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005690:Galactose / Q000097:blood / Q000172:deficiency*; D006031:Glycosylation; D015658:HIV Infections / Q000097:blood* / Q000276:immunology; D015497:HIV-1; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007132:Immunoglobulin Isotypes / Q000097:blood; D037102:Lectins / Q000378:metabolism; D008297:Male; D008875:Middle Aged
D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D037102:Lectins; D005690:Galactose