scholarly journals Comprehensive Cross-Clade Neutralization Analysis of a Panel of Anti-Human Immunodeficiency Virus Type 1 Monoclonal Antibodies

2004 ◽  
Vol 78 (23) ◽  
pp. 13232-13252 ◽  
Author(s):  
James M. Binley ◽  
Terri Wrin ◽  
Bette Korber ◽  
Michael B. Zwick ◽  
Meng Wang ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Monoclonal Antibodies ◽  
Binding Site ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Clade B ◽  
Immunodeficiency Virus ◽  
Clade C ◽  
Cd4 Binding Site

ABSTRACT Broadly neutralizing monoclonal antibodies (MAbs) are potentially important tools in human immunodeficiency virus type 1 (HIV-1) vaccine design. A few rare MAbs have been intensively studied, but we still have a limited appreciation of their neutralization breadth. Using a pseudovirus assay, we evaluated MAbs from clade B-infected donors and a clade B HIV+ plasma against 93 viruses from diverse backgrounds. Anti-gp120 MAbs exhibited greater activity against clade B than non-B viruses, whereas anti-gp41 MAbs exhibited broad interclade activity. Unexpectedly, MAb 4E10 (directed against the C terminus of the gp41 ectodomain) neutralized all 90 viruses with moderate potency. MAb 2F5 (directed against an epitope adjacent to that of 4E10) neutralized 67% of isolates, but none from clade C. Anti-gp120 MAb b12 (directed against an epitope overlapping the CD4 binding site) neutralized 50% of viruses, including some from almost every clade. 2G12 (directed against a high-mannose epitope on gp120) neutralized 41% of the viruses, but none from clades C or E. MAbs to the gp120 V3 loop, including 447-52D, neutralized a subset of clade B viruses (up to 45%) but infrequently neutralized other clades (≤7%). MAbs b6 (directed against the CD4 binding site) and X5 (directed against a CD4-induced epitope of gp120) neutralized only sensitive primary clade B viruses. The HIV+ plasma neutralized 70% of the viruses, including some from all major clades. Further analysis revealed five neutralizing immunotypes that were somewhat associated with clades. As well as the significance for vaccine design, our data have implications for passive-immunization studies in countries where clade C viruses are common, given that only MAbs b12 and 4E10 were effective against viruses from this clade.

scholarly journals Fine Mapping of the Interaction of Neutralizing and Nonneutralizing Monoclonal Antibodies with the CD4 Binding Site of Human Immunodeficiency Virus Type 1 gp120

2003 ◽  
Vol 77 (1) ◽  
pp. 642-658 ◽  
Author(s):  
Ralph Pantophlet ◽  
Erica Ollmann Saphire ◽  
Pascal Poignard ◽  
Paul W. H. I. Parren ◽  
Ian A. Wilson ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Monoclonal Antibodies ◽  
Binding Site ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Alanine Scanning Mutagenesis ◽  
Immunodeficiency Virus ◽  
Cd4 Binding Site ◽  
Monomeric Gp120

ABSTRACT Alanine scanning mutagenesis was performed on monomeric gp120 of human immunodeficiency virus type 1 to systematically identify residues important for gp120 recognition by neutralizing and nonneutralizing monoclonal antibodies (MAbs) to the CD4 binding site (CD4bs). Substitutions that affected the binding of broadly neutralizing antibody b12 were compared to substitutions that affected the binding of CD4 and of two nonneutralizing anti-CD4bs antibodies (b3 and b6) with affinities for monomeric gp120 comparable to that of b12. Not surprisingly, the sensitivities to a number of amino acid changes were similar for the MAbs and for CD4. However, in contrast to what was seen for the MAbs, no enhancing mutations were observed for CD4, suggesting that the virus has evolved toward an optimal gp120-CD4 interaction. Although the epitope maps of the MAbs overlapped, a number of key differences between b12 and the other two antibodies were observed. These differences may explain why b12, in contrast to nonneutralizing antibodies, is able to interact not only with monomeric gp120 but also with functional oligomeric gp120 at the virion surface. Neutralization assays performed with pseudovirions bearing envelopes from a selection of alanine mutants mostly showed a reasonable correlation between the effects of the mutations on b12 binding to monomeric gp120 and neutralization efficacy. However, some mutations produced an effect on b12 neutralization counter to that predicted from gp120 binding data. It appears that these mutations have different effects on the b12 epitope on monomeric gp120 and functional oligomeric gp120. To determine whether monomeric gp120 can be engineered to preferentially bind MAb b12, recombinant gp120s were generated containing combinations of alanine substitutions shown to uniquely enhance b12 binding. Whereas b12 binding was maintained or increased, binding by five nonneutralizing anti-CD4bs MAbs (b3, b6, F105, 15e, and F91) was reduced or completely abolished. These reengineered gp120s are prospective immunogens that may prove capable of eliciting broadly neutralizing antibodies.

scholarly journals The N-Terminal V3 Loop Glycan Modulates the Interaction of Clade A and B Human Immunodeficiency Virus Type 1 Envelopes with CD4 and Chemokine Receptors

2000 ◽  
Vol 74 (23) ◽  
pp. 11008-11016 ◽  
Author(s):  
Susan E. Malenbaum ◽  
David Yang ◽  
Lisa Cavacini ◽  
Marshall Posner ◽  
James Robinson ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Binding Site ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Chemokine Receptors ◽  
V3 Loop ◽  
Clade B ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We investigated the underlying mechanism by which the highly conserved N-terminal V3 loop glycan of gp120 conferred resistance to neutralization of human immunodeficiency virus type 1 (HIV-1). We find that the presence or absence of this V3 glycan on clade A and B viruses accorded various degrees of susceptibility to neutralization by antibodies to the CD4 binding site, CD4-induced epitopes, and chemokine receptors. Our data suggest that this carbohydrate moiety on gp120 blocks access to the binding site for CD4 and modulates the chemokine receptor binding site of phenotypically diverse clade A and clade B isolates. Its presence also contributes to the masking of CD4-induced epitopes on clade B envelopes. These findings reveal a common mechanism by which diverse HIV-1 isolates escape immune recognition. Furthermore, the observation that conserved functional epitopes of HIV-1 are more exposed on V3 glycan-deficient envelope glycoproteins provides a basis for exploring the use of these envelopes as vaccine components.

scholarly journals Clade-Specific Differences between Human Immunodeficiency Virus Type 1 Clades B and C: Diversity and Correlations in C3-V4 Regions of gp120

2007 ◽  
Vol 81 (9) ◽  
pp. 4886-4891 ◽  
Author(s):  
S. Gnanakaran ◽  
Dorothy Lang ◽  
Marcus Daniels ◽  
Tanmoy Bhattacharya ◽  
Cynthia A. Derdeyn ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Current Knowledge ◽  
Viral Glycoprotein ◽  
Clade B ◽  
Immunodeficiency Virus ◽  
Clade C ◽  
And Function

ABSTRACT Current knowledge of human immunodeficiency virus type 1 envelope (Env) glycoprotein structure and function is based on studies of clade B viruses. We present evidence of sequence and structural differences in viral glycoprotein gp120 between clades B and C. In clade C, the C3 region α2-helix exhibits high sequence entropy at the polar face but maintains its amphipathicity, whereas in clade B it accommodates hydrophobic residues. The V4 hypervariable domain in clade C is shorter than that in clade B. Generally, shorter V4 loops are incompatible with a glycine occurring in the α2-helix in clade C, an intriguing association that could be exploited to inform Env immunogen design.

scholarly journals Antigenic Variation within the CD4 Binding Site of Human Immunodeficiency Virus Type 1 gp120: Effects on Chemokine Receptor Utilization

2001 ◽  
Vol 75 (12) ◽  
pp. 5593-5603 ◽  
Author(s):  
Anthea L. Hammond ◽  
Julie Lewis ◽  
Jackie May ◽  
Jan Albert ◽  
Peter Balfe ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Binding Site ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Antigenic Variation ◽  
Coreceptor Usage ◽  
Immunodeficiency Virus ◽  
Cd4 Binding Site ◽  
Chimeric Viruses

ABSTRACT To assess the antigenicity of envelope glycoproteins derived from primary human immunodeficiency virus type 1 populations, their interactions with the receptor CD4, and their coreceptor usage, we have cloned and expressed multiple gp120 proteins from a number of primary virus isolates. Characterization of these proteins showed a high degree of antigenic polymorphism both within the CD4 binding site and in defined neutralization epitopes, which may partially account for the general resistance of primary isolates to neutralizing agents. Furthermore, chimeric viruses expressing gp120 proteins with reduced CD4 binding abilities are viable, suggesting that primary viruses may require a less avid interaction with the receptor CD4 to initiate infection than do their laboratory-adapted counterparts. The coreceptor usage of chimeric viruses was related to the ability of the virus to bind CD4, with reduced CD4 binding correlating with preferential usage of CXCR4. Changes in coreceptor usage mapped to sequence changes in the C2 and V4 regions, with no changes seen in the V3 region.

scholarly journals Type-Specific Epitopes Targeted by Monoclonal Antibodies with Exceptionally Potent Neutralizing Activities for Selected Strains of Human Immunodeficiency Virus Type 1 Map to a Common Region of the V2 Domain of gp120 and Differ Only at Single Positions from the Clade B Consensus Sequence

2006 ◽  
Vol 81 (3) ◽  
pp. 1424-1432 ◽  
Author(s):  
W. J. Honnen ◽  
C. Krachmarov ◽  
S. C. Kayman ◽  
M. K. Gorny ◽  
S. Zolla-Pazner ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Monoclonal Antibodies ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Consensus Sequence ◽  
Clade B ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Potent Neutralization

ABSTRACT Only a few monoclonal antibodies (MAbs) have been isolated that recognize conserved sites in human immunodeficiency virus type 1 (HIV-1) Env proteins and possess broad neutralizing activities. Other MAbs directed against targets in various domains of Env have been described that are strongly neutralizing, but they possess limited breadth. One such MAb, 2909, possesses a uniquely potent neutralizing activity specific for a quaternary epitope on SF162 Env that requires the presence of both the V2 and the V3 domains. We now show that replacement of the SF162 V3 sequence with consensus V3 sequences of multiple subtypes led to attenuated but still potent neutralization by 2909 and that the main determinants for the type specificity of 2909 reside in the V2 domain. A substitution at position 160 completely eliminated 2909 reactivity, and mutations at position 167 either attenuated or potentiated neutralization by this antibody. Different substitutions at the same positions in V2 were previously shown to introduce epitopes recognized by MAbs 10/76b and C108g and to allow potent neutralization by these MAbs. Two substitutions at key positions in the V2 domain of JR-FL Env also allowed potent expression of the 2909 epitope, and single substitutions in YU2 V2 were sufficient for expression of the 2909, C108g, and 10/76b epitopes. These results demonstrate that the minimal epitopes for 2909, C108g, and 10/76b differed from that of the clade B consensus sequence only at single positions and suggest that all three MAbs recognize distinct variants of a relatively conserved sequence in V2 that is a particularly sensitive mediator of HIV-1 neutralization.

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