Sequence and specificity analysis of recombinant human Fab anti-Rh D isolated by phage display.
OBJECTIVE
Hyperimmune anti-Rh D serum is worldwide in short supply. As a first step to develop an alternative source of Rh D antibodies, we describe in this study the isolation and characterization of recombinant anti-Rh D Fab fragments.


METHODS
Peripheral blood mononuclear cells harvested from a hyperimmunized donor were used to construct two combinatorial Fab libraries. Phages expressing these Fab fragments were selected on whole red blood cells followed by testing of positive clones in an indirect hemagglutination assay.


RESULTS
Individual Fab clones are of high affinity and competitively inhibit the binding of a registered anti-D immunoglobulin. The Fab clones are also specific against the partial D phenotypes, Rh33, DIII, DIVa, DIVb, DVa, and DVII. The 13 different but highly homologous clones express preferentially VH3 segments.


CONCLUSIONS
These Fab fragments show potential for the development of a new generation of therapeutic anti-Rh D reagents.
Miescher
S
S
ZLB Central Laboratory, Blood Transfusion Service SRC, Inselspital, Bern, Switzerland. Sylvia.Miescher@insel.ch
Vogel
M
M
Biaggi
C
C
Ramseyer
V
V
Hustinx
H
H
Eicher
N
N
Imboden
M A
MA
Spycher
M O
MO
Amstutz
H
H
Stadler
B M
BM
D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000235:genetics*; D003001:Cloning, Molecular; D006386:Hemagglutination Tests; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D008297:Male; D008969:Molecular Sequence Data; D019151:Peptide Library; D011994:Recombinant Proteins / Q000276:immunology; D018029:Rho(D) Immune Globulin / Q000276:immunology*; D012680:Sensitivity and Specificity
D007140:Immunoglobulin Fab Fragments; D019151:Peptide Library; D011994:Recombinant Proteins; D018029:Rho(D) Immune Globulin