The restricted use of IGHV3 superspecies genes in anti-Rh is not limited to hyperimmunized anti-D donors.
BACKGROUND
Antibodies produced against the D antigen make use of IGHV genes restricted to the IGHV3 superfamily. These findings are based on the IGHV gene analysis in anti-D-producing B cells from hyperimmunized donors, however, and therefore the restriction might be due to the hyperimmunization. In this study the IGHV gene usage of anti-Rh-producing B cells in a woman who was immunized in the last trimester of her pregnancy was analyzed.


METHODS
Serologic analysis was performed by absorption and elution. Antibody-dependent cellular cytotoxicity (ADCC) of the different anti-Rh was determined. A phage display library was constructed from 2.2 x 10(6) isolated B cells and pannings were performed with red cells of the r'r, R1R1, and R2R2 phenotype.


RESULTS
A plasma sample of the immunized person showed high levels of both anti-D and anti-G and low levels of anti-C. Anti-D and anti-G contributed equally strong to the ADCC whereas anti-C did not. Eighteen anti-D-, 5 anti-G-, and 1 anti-C-specific phage clones were found, of which 16, 2, and 1 used the IGHV3s genes, respectively.


CONCLUSIONS
For the first time a restriction to the IGHV3s genes in anti-D in a naturally immunized pregnant woman is shown. Moreover, the use of IGHV3s genes appears to be present in anti-C and anti-G as well. Therefore, it is concluded that restricted IGHV3s gene usage in anti-D is not due to hyperimmunization but due to characteristics of the Rh antigens and the intrinsic binding capacities of IGHV3s genes, supporting the common Rh footprint hypothesis.
Dohmen
Serge E
SE
Sanquin Research at CLB and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
Verhagen
Onno J H M
OJ
Muit
Jessica
J
Ligthart
Peter C
PC
van der Schoot
C Ellen
CE
D000920:Antibody-Dependent Cell Cytotoxicity; D001782:Blood Donors; D005260:Female; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D006801:Humans; D007114:Immunization; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D019151:Peptide Library; D012204:Rh-Hr Blood-Group System / Q000276:immunology*
D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D019151:Peptide Library; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen