Heterogeneity of human anti-pig natural antibodies cross-reactive with the Gal(alpha1,3)Galactose epitope.
BACKGROUND
The cell surface carbohydrate moiety, Gal(alpha1,3)Galactose (alphaGal), has been implicated as the major determinant recognized by more than 80% of human anti-porcine natural antibodies (NAb). An ELISA system was developed for the detection of this subpopulation of porcine cell-reactive NAb using synthetic alphaGal conjugated to bovine serum albumin.


METHODS
A screen of 95 human serum samples by this method demonstrated marked variability in the alphaGal reactivity of unrelated donors. The percentage of alphaGal-reactive NAb relative to total immunoglobulin was determined for 10 donors.


RESULTS
alphaGal-reactive NAb comprised 1.0-2.4% of total serum IgG, whereas the range was from 3.9% to 8.0% for IgM.


CONCLUSIONS
The higher level of alphaGal-reactive IgM suggests that xenoreactive NAbs may be the product of germ-line genes. Two-dimensional gel analysis of affinity-purified alphaGal-reactive NAb from two donors provided evidence suggesting that IgM from this subpopulation of NAb were restricted in protein charge heterogeneity.
McMorrow
I M
IM
Transplantation Biology Research Center, Massachusetts General Hospital/Harvard Medical School, Boston 02129, USA.
Comrack
C A
CA
Sachs
D H
DH
DerSimonian
H
H
D000328:Adult; D000818:Animals; D000906:Antibodies / Q000235:genetics*; D000937:Antigen-Antibody Reactions / Q000276:immunology*; D003429:Cross Reactions; D004187:Disaccharides / Q000276:immunology*; D015180:Electrophoresis, Gel, Two-Dimensional; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000235:genetics; D005434:Flow Cytometry; D005803:Genes, Immunoglobulin; D018740:Genetic Heterogeneity; D006801:Humans; D007113:Immunity, Innate; D007135:Immunoglobulin Variable Region / Q000235:genetics; D013552:Swine
D000906:Antibodies; D004187:Disaccharides; D000939:Epitopes; D007135:Immunoglobulin Variable Region; C055075:galactosyl-(1-3)galactose