Gain-of-Sensitivity Mutations in a Trim5-Resistant Primary Isolate of Pathogenic SIV Identify Two Independent Conserved Determinants of Trim5α Specificity

ABSTRACT Macrophagetropic R5 human immunodeficiency virus type 1 (HIV-1) isolates often evolve into dualtropic R5X4 variants during disease progression. The structural basis for CCR5 coreceptor function has been studied in a limited number of prototype strains and suggests that R5 and R5X4 Envs interact differently with CCR5. However, differences between unrelated viruses may reflect strain-specific factors and do not necessarily represent changes resulting from R5 to R5X4 evolution of a virus in vivo. Here we addressed CCR5 domains involved in fusion for a large set of closely related yet functionally distinct variants within a primary isolate swarm, employing R5 and R5X4 Envs derived from the HIV-1 89.6PI quasispecies. R5 variants of 89.6PI could fuse using either N-terminal or extracellular loop CCR5 sequences in the context of CCR5/CXCR2 chimeras, similar to the unrelated R5 strain JRFL, but R5X4 variants of 89.6PI were highly dependent on the CCR5 N terminus. Similarly, R5 89.6PI variants and isolate JRFL tolerated N-terminal CCR5 deletions, but fusion by most R5X4 variants was markedly impaired. R5 89.6PI Envs also tolerated multiple extracellular domain substitutions, while R5X4 variants did not. In contrast to CCR5 use, fusion by R5X4 variants of 89.6PI was largely independent of the CXCR4 N-terminal region. Thus, R5 and R5X4 species from a single swarm differ in how they interact with CCR5. These results suggest that R5 Envs possess a highly plastic capacity to interact with multiple CCR5 regions and support the concept that viral evolution in vivo results from the emergence of R5X4 variants with the capacity to use the CXCR4 extracellular loops but demonstrate less-flexible interactions with CCR5 that are strongly dependent on the N-terminal region.

Download Full-text

Glycoprotein Exchange Vectors Based on Vesicular Stomatitis Virus Allow Effective Boosting and Generation of Neutralizing Antibodies to a Primary Isolate of Human Immunodeficiency Virus Type 1

Journal of Virology ◽

10.1128/jvi.74.23.10903-10910.2000 ◽

2000 ◽

Vol 74 (23) ◽

pp. 10903-10910 ◽

Cited By ~ 116

Author(s):

Nina F. Rose ◽

Anjeanette Roberts ◽

Linda Buonocore ◽

John K. Rose

Keyword(s):

Human Immunodeficiency Virus ◽

G Protein ◽

Neutralizing Antibodies ◽

High Titer ◽

Primary Isolate ◽

Effective Vaccine ◽

Fourfold Increase ◽

Immunodeficiency Virus ◽

Vesicular Stomatitis ◽

Hiv Envelope

ABSTRACT Live recombinant vesicular stomatitis viruses (VSVs) expressing foreign antigens are highly effective vaccine vectors. However, these vectors induce high-titer neutralizing antibody directed at the single VSV glycoprotein (G), and this antibody alone can prevent reinfection and boosting with the same vector. To determine if efficient boosting could be achieved by changing the G protein of the vector, we have developed two new recombinant VSV vectors based on the VSV Indiana serotype but with the G protein gene replaced with G genes from two other VSV serotypes, New Jersey and Chandipura. These G protein exchange vectors grew to titers equivalent to wild-type VSV and induced similar neutralizing titers to themselves but no cross-neutralizing antibodies to the other two serotypes. The effectiveness of these recombinant VSV vectors was illustrated in experiments in which sequential boosting of mice with the three vectors, all encoding the same primary human immunodeficiency virus (HIV) envelope protein, gave a fourfold increase in antibody titer to an oligomeric HIV envelope compared with the response in animals receiving the same vector three times. In addition, only the animals boosted with the exchange vectors produced antibodies neutralizing the autologous HIV primary isolate. These VSV envelope exchange vectors have potential as vaccines in immunizations when boosting of immune responses may be essential.

Download Full-text

Identification of New and UnusualrevandnefTranscripts Expressed by an HIV Type 1 Primary Isolate

AIDS Research and Human Retroviruses ◽

10.1089/aid.2013.0053 ◽

2013 ◽

Vol 29 (7) ◽

pp. 1075-1078 ◽

Cited By ~ 2

Author(s):

Yolanda Vega ◽

Elena Delgado ◽

Cristina Carrera ◽

Paloma Nebreda ◽

Aurora Fernández-García ◽

...

Keyword(s):

Primary Isolate ◽

Hiv Type 1

Download Full-text

Primary Isolate Neutralization by HIV Type 1-Infected Patient Sera in the Era of Highly Active Antiretroviral Therapy

AIDS Research and Human Retroviruses ◽

10.1089/088922299309856 ◽

1999 ◽

Vol 15 (17) ◽

pp. 1563-1571 ◽

Cited By ~ 28

Author(s):

Kimberly Dreyer ◽

Esper G. Kallas ◽

Vicente Planelles ◽

David Montefiori ◽

Michael P. McDermott ◽

...

Keyword(s):

Antiretroviral Therapy ◽

Highly Active Antiretroviral Therapy ◽

Infected Patient ◽

Primary Isolate ◽

Highly Active ◽

Hiv Type 1

Download Full-text

Antibodies That Are Cross-Reactive for Human Immunodeficiency Virus Type 1 Clade A and Clade B V3 Domains Are Common in Patient Sera from Cameroon, but Their Neutralization Activity Is Usually Restricted by Epitope Masking

Journal of Virology ◽

10.1128/jvi.79.2.780-790.2005 ◽

2005 ◽

Vol 79 (2) ◽

pp. 780-790 ◽

Cited By ~ 68

Author(s):

Chavdar Krachmarov ◽

Abraham Pinter ◽

William J. Honnen ◽

Miroslaw K. Gorny ◽

Phillipe N. Nyambi ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Fusion Proteins ◽

Primary Isolate ◽

Neutralization Activity ◽

Neutralizing Activity ◽

Clade B ◽

Immunodeficiency Virus

ABSTRACT Sera from human immunodeficiency virus type 1 (HIV-1)-infected North American patients recognized a fusion protein expressing a V3 loop from a clade B primary isolate virus (JR-CSF) but not from a clade A primary isolate virus (92UG037.8), while most sera from Cameroonian patients recognized both fusion proteins. Competition studies of consensus V3 peptides demonstrated that the majority of the cross-reactive Cameroonian sera contained cross-reactive antibodies that reacted strongly with both V3 sequences. V3-specific antibodies purified from all six cross-reactive sera examined had potent neutralizing activity for virus pseudotyped with envelope proteins (Env) from SF162, a neutralization-sensitive clade B primary isolate. For four of these samples, neutralization of SF162 pseudotypes was blocked by both the clade A and clade B V3 fusion proteins, indicating that this activity was mediated by cross-reactive antibodies. In contrast, the V3-reactive antibodies from only one of these six sera had significant neutralizing activity against viruses pseudotyped with Envs from typically resistant clade B (JR-FL) or clade A (92UG037.8) primary isolates. However, the V3-reactive antibodies from these cross-reactive Cameroonian sera did neutralize virus pseudotyped with chimeric Envs containing the 92UG037.8 or JR-FL V3 sequence in Env backbones that did not express V1/V2 domain masking of V3 epitopes. These data indicated that Cameroonian sera frequently contain cross-clade reactive V3-directed antibodies and indicated that the typical inability of such antibodies to neutralize typical, resistant primary isolate Env pseudotypes was primarily due to indirect masking effects rather than to the absence of the target epitopes.

Download Full-text

The role of the third strand in gp120 conformation and neutralization sensitivity of the HIV-1 primary isolate DH012

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.261359098 ◽

2001 ◽

Vol 98 (26) ◽

pp. 15227-15232 ◽

Cited By ~ 24

Author(s):

C.-B. Zhu ◽

L. Zhu ◽

S. Holz-Smith ◽

T. J. Matthews ◽

C. H. Chen

Keyword(s):

Primary Isolate ◽

Neutralization Sensitivity ◽

The Third ◽

Hiv 1

Download Full-text

Characteristics of a Block to Entry via an HIV-2 Envelope, MCR

10.1101/177808 ◽

2017 ◽

Author(s):

Eleanor R. Gray

Keyword(s):

Envelope Protein ◽

Cell Types ◽

Surface Expression ◽

Productive Infection ◽

Primary Isolate ◽

Cellular Biology ◽

Cell Surface Expression ◽

Pseudotyped Virus ◽

Specific Cell ◽

Cell Type

Successful viral infection depends not only on targeting the correct cell type, but also on the route taken into the cell. After entry, a retrovirus must reverse transcribe its genome and access the nucleus. Blocks to infection can arise at many different stages of the cycle; if they occur only in some cell types it can reveal hitherto unknown aspects of viral or cellular biology. A block to infection of a primary isolate of HIV-2 was previously identified in specific cell types. In this study, parameters of route of entry of the envelope protein from this primary isolate, MCR, were investigated. A critical component of the block acts at a pre-reverse transcription stage, as virions pseudotyped with MCR envelope did not undergo fusion and entry rates commensurate with productive infection. Furthermore, expression of p56lck, which regulates CD4 surface expression, partially rescued infection of MCR envelope-pseudotyped virus in restrictive cell types. Based on these findings, we propose that a part of this block results from poor cell-surface expression of CD4.

Download Full-text

Additive Effects Characterize the Interaction of Antibodies Involved in Neutralization of the Primary Dualtropic Human Immunodeficiency Virus Type 1 Isolate 89.6

Journal of Virology ◽

10.1128/jvi.75.19.9177-9186.2001 ◽

2001 ◽

Vol 75 (19) ◽

pp. 9177-9186 ◽

Cited By ~ 39

Author(s):

Florence Verrier ◽

Arthur Nádas ◽

Miroslaw K. Gorny ◽

Susan Zolla-Pazner

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Primary Isolate ◽

Mathematical Treatment ◽

Type I ◽

Additive Effects ◽

Immunodeficiency Virus ◽

Anti Hiv ◽

Hiv 1

ABSTRACT Human immunodeficiency virus-type I (HIV-1) infection elicits antibodies (Abs) directed against several regions of the gp120 and gp41 envelope glycoproteins. Many of these Abs are able to neutralize T-cell-line-adapted strains (TCLA) of HIV-1, but only a few effectively neutralize primary HIV-1 isolates. The nature of HIV-1 neutralization has been carefully studied using human monoclonal Abs (MAbs), and the ability of such MAbs to act in synergy to neutralize HIV-1 has also been extensively studied. However, most synergy studies have been conducted using TCLA strains. To determine the nature of Ab interaction in HIV-1 primary isolate neutralization, a panel of 12 anti-HIV-1 human immunoglobulin G (IgG) MAbs, specific for epitopes in gp120 and gp41, were used. Initial tests showed that six of these MAbs, as well as sCD4, used individually, were able to neutralize the dualtropic primary isolate HIV-189.6; MAbs giving significant neutralization at 2 to 10 μg/ml included 2F5 (anti-gp41), 50-69 (anti-gp41), IgG1b12 (anti-gp120CD4bd), 447-52D (anti-gp120V3), 2G12 (anti-gp120), and 670-D (anti-gp120C5). For studies of reagent interaction, 16 binary combinations of reagents were tested for their ability to neutralize HIV-189.6. Reagent combinations tested included one neutralizing MAb with sCD4, six pairs consisting of two neutralizing MAbs, and nine pairs consisting of one neutralizing MAb with another non-neutralizing MAb. To assess the interaction of the latter type of combination, a new mathematical treatment of reagent interaction was developed since previously used methods could be used only when both reagents neutralize. Synergy was noted between sCD4 and a neutralizing anti-gp120V3 MAb. Antagonism was noted between two pairs of anti-gp41 MAbs (one neutralizing and one non-neutralizing). All of the other 13 pairs of MAbs tested displayed only additive effects. These studies suggest that Abs rarely act in synergy to neutralize primary isolate HIV-189.6; many anti-HIV-1 Abs act additively to mediate this biological function.

Download Full-text