Potent neutralization of primary human immunodeficiency virus clade C isolates with a synergistic combination of human monoclonal antibodies raised against clade B.
OBJECTIVE
We investigated the ability of several human neutralizing monoclonal antibodies (mAbs), originally raised against human immunodeficiency virus (HIV) clade B isolates, to neutralize primary clade C isolates as single agents and in combination.


METHODS
HIV clade C isolates from five different countries were tested for susceptibility to neutralization by anti-clade B mAbs in human peripheral blood mononuclear cells. Monoclonal antibody combinations were evaluated for possible synergy.


RESULTS
All 20 primary HIV clade C isolates could be neutralized 97.5% to 100% by a quadruple combination of mAbs IgG1b12, 2G12, 2F5, and 4E10. These mAbs recognized conserved epitopes and were highly synergistic, resulting in strong cross-clade neutralization.


CONCLUSIONS
In our previous experiment, a synergistic combination of human neutralizing mAbs protected all macaque neonates against oral challenge with a simian-human immunodeficiency virus encoding HIV env. Together, our data suggest that passive immunization with currently available anti-clade B mAbs could play a role in preventing HIV clade C transmission through breastfeeding.
Xu
W
W
Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Smith-Franklin
B A
BA
Li
P L
PL
Wood
C
C
He
J
J
Du
Q
Q
Bhat
G J
GJ
Kankasa
C
C
Katinger
H
H
Cavacini
L A
LA
Posner
M R
MR
Burton
D R
DR
Chou
T C
TC
Ruprecht
R M
RM
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D004357:Drug Synergism; D015483:HIV Antibodies / Q000276:immunology; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000276:immunology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D009500:Neutralization Tests
D000911:Antibodies, Monoclonal; D015483:HIV Antibodies