HIV type 1 subtype E-infected patients with broadened, dual (B/E) V3 loop serology have increased cross-neutralizing antibodies.
The two prevalent subtypes of HIV-1 circulating in Thailand are subtypes E and B. While the most prevalent subtype continues to be E using molecular typing assays, immunologically, a subset of subtype E-infected patients (3.4% in 1997) have binding antibodies to both the E and B V3 loops in a peptide ELISA. To assess the potential function of this dual (B/E) V3 reactivity, plasmas from patients with genetically defined HIV-1 subtype E infection and either E or B/E V3 serotypes were compared for magnitude and breadth of neutralization of seven primary and laboratory-adapted subtype B and E viruses. Dually reactive (B/E) plasmas showed significantly increased cross-neutralizing activity against subtype B viruses (p < 0.001), and increased neutralization of the panel of viruses overall (p < 0.02), as compared to monoreactive E serotype plasmas. While the total envelope binding antibody titers to both subtype B and E envelopes did not differ significantly between the E and B/E plasmas, 67% of B/E plasmas neutralized >50% of the viruses in the panel, and only 14% of E plasmas showed this broadened neutralizing activity. These data suggest that dual (B/E) V3 loop reactivity may be a marker of broader immune recognition of HIV envelope epitopes in subtype E-infected patients. V3 loop antibody, perhaps in conjunction with antibodies to additional epitopes, may play a role in neutralization of virus isolates from Thailand.
Polonis
V R
VR
AFRIMS, Bangkok, 10400 Thailand.
De Souza
M S
MS
Chanbancherd
P
P
Chantakulkij
S
S
Jugsudee
A
A
Loomis-Price
L D
LD
Vancott
T C
TC
Garner
R
R
Markowitz
L E
LE
Brown
A E
AE
Birx
D L
DL
D000595:Amino Acid Sequence; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D015483:HIV Antibodies / Q000097:blood / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000276:immunology*; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics / Q000276:immunology; D006801:Humans; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology*; D012703:Serotyping; D013785:Thailand
D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments