Differential reactivity of mouse monoclonal anti-HBs antibodies with recombinant mutant HBs antigens.
OBJECTIVE
To investigate the reactivity of a panel of 8 mouse anti-hepatitis B surface antigen (HBsAg) monoclonal antibodies (mAbs) using a collection of 9 recombinant HBsAg mutants with a variety of amino acid substitutions mostly located within the "a" region.


METHODS
The entire HBs genes previously cloned into a mammalian expression vector were transiently transfected into COS7 cells. Two standard unmutated sequences of the ayw and adw subtypes served as controls. Secreted mutant proteins were collected and measured by three commercial diagnostic immunoassays to assess transfection efficiency. Reactivity of anti-HBs mAbs with mutated HBsAgs was determined by sandwich enzyme-linked immunosorbent assay (ELISA).


RESULTS
Reactivity of anti-HBs mAbs with mutated HBsAgs revealed different patterns. While three mutants reacted strongly with all mAbs, two mutants reacted weakly with only two mAbs and the remaining proteins displayed variable degrees of reactivity towards different mAbs. Accordingly, four groups of mAbs with different but overlapping reactivity patterns could be envisaged. One group consisting of two mAbs (37C5-S7 and 35C6-S11) was found to recognize stable linear epitopes conserved in all mutants. Mutations outside the "a" determinant at positions 120 (P-->S), 123(T-->N) and 161 (M-->T) were found to affect reactivity of these mAbs.


CONCLUSIONS
Our findings could have important implications for biophysical studies, vaccination strategies and immunotherapy of hepatitis B virus (HBV) mutants.
Roohi
Azam
A
Department of Immunology, School of Public Health, Tehran University of Medical Sciences, PO Box 6446-14133, Tehran, Iran.
Yazdani
Yaghoub
Y
Khoshnoodi
Jalal
J
Jazayeri
Seyed Mohammad
SM
Carman
William F
WF
Chamankhah
Mahmood
M
Rashedan
Manley
M
Shokri
Fazel
F
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D000956:Antigens, Viral / Q000737:chemistry; D055592:Biophysical Phenomena; D001703:Biophysics; D019556:COS Cells; D002522:Chlorocebus aethiops; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006510:Hepatitis B Antibodies / Q000737:chemistry*; D006514:Hepatitis B Surface Antigens / Q000737:chemistry* / Q000276:immunology; D007118:Immunoassay; D007167:Immunotherapy / Q000379:methods; D051379:Mice; D010957:Plasmids / Q000378:metabolism; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry; D014162:Transfection
D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D000939:Epitopes; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D011994:Recombinant Proteins