Production of recombinant murine-human chimeric IgM and IgG anti-Js(b) for use in the clinical laboratory.
BACKGROUND
Directly agglutinating MoAbs are more useful than IgG MoAbs of murine origin for typing RBCs from donors and patients. The molecular manipulation and conversion of a murine IgG MoAb into mouse- human chimeric IgM and IgG antibodies are described.


METHODS
cDNA encoding the variable heavy- and light-chain genes of a murine hybridoma anti-Jsb cell line (MIMA-8) were cloned into human IgM or IgG expression vectors, which were then separately stably transfected into SP2/0-Ag14 B-cells. The secreted antibodies were screened by ELISA and analyzed by flow cytometry and hemagglutination.


RESULTS
Forty percent (16 of 40) of the stable clones secreted IgM and 66 percent (12 of 18) of the stable clones secreted IgG. The chimeric IgM from the highest expressing clone reacted 4+ in LISS at room temperature. The chimeric IgG from one clone reacted 4+ by the IAT, resembling the specificity of the original murine antibody. Both manipulated MoAbs reacted specifically with RBCs as assessed by flow cytometry.


CONCLUSIONS
Human-mouse chimeric IgM and IgG from a murine IgG MoAb anti-Jsb has been successfully engineered for use in the clinical laboratory. This approach can potentially be used to manipulate other murine MoAbs to blood group antigens into more clinically useful human isotypes.
Huang
T J
TJ
Immunochemistry Laboratory, New York Blood Center, New York, New York 10021, USA.
Reid
M E
ME
Halverson
G R
GR
Yazdanbakhsh
K
K
D000818:Animals; D001483:Base Sequence; D001788:Blood Grouping and Crossmatching; D002478:Cells, Cultured; D005434:Flow Cytometry; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000235:genetics; D007075:Immunoglobulin M / Q000096:biosynthesis*; D007626:Kell Blood-Group System / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*
D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M; D007626:Kell Blood-Group System; D011993:Recombinant Fusion Proteins