In vivo T-cell depletion enhances production of anti-GALalpha1,3GAL natural antibodies in alpha1,3-galactosyltransferase-deficient mice.
BACKGROUND
It has been reported that T-cell depletion by in vivo treatment with monoclonal antibodies results in polyclonal B-cell activation. However, its effects on B cells responding to Galalpha1,3Gal (Gal) epitopes remain unknown.


METHODS
alpha1,3-Galactosyltransferase-deficient (GalT-/-) mice were treated with depleting anti-CD4 and CD8 monoclonal antibodies. The kinetics of anti-Gal natural antibodies (NAb) and total immunoglobulin levels in their sera were evaluated. The frequencies of anti-Gal NAb-producing cells were determined in the various tissues of GalT-/- mice by enzyme-linked immunospot assay.


RESULTS
In vivo T-cell depletion led to significant increases in both anti-Gal IgM and total IgM levels in sera of GalT-/- mice, but did not influence either anti-Gal IgG or total IgG levels. An increased frequency of anti-Gal and total IgM-producing cells was observed in the spleens and bone marrow of T-cell-depleted GalT-/-mice but not in peritoneal cavity cells.


CONCLUSIONS
In vivo T-cell depletion facilitates anti-Gal IgM production, suggesting that T cells deliver inhibitory signals to B cells responding to Gal.
Ohdan
H
H
Transplantation Biology Research Center, Massachusetts General Hospital/Harvard Medical School, Boston 02129, USA.
Yang
Y G
YG
Swenson
K G
KG
Thall
A D
AD
Sykes
M
M
D000818:Animals; D000906:Antibodies / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000917:Antibody Formation / Q000502:physiology; D001854:Bone Marrow Cells / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology; D004187:Disaccharides / Q000276:immunology*; D005700:Galactosyltransferases / Q000172:deficiency* / Q000235:genetics; D007075:Immunoglobulin M / Q000097:blood; D051379:Mice; D018345:Mice, Knockout / Q000235:genetics; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology* / Q000187:drug effects
D000906:Antibodies; D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D016827:CD8 Antigens; D004187:Disaccharides; D007075:Immunoglobulin M; C055075:galactosyl-(1-3)galactose; D005700:Galactosyltransferases; C047006:N-acetyllactosaminide alpha-1,3-galactosyltransferase