scholarly journals Development of Calibrated Viral Load Standards for Group M Subtypes of Human Immunodeficiency Virus Type 1 and Performance of an Improved AMPLICOR HIV-1 MONITOR Test with Isolates of Diverse Subtypes

1999 ◽  
Vol 37 (8) ◽  
pp. 2557-2563 ◽  
Author(s):  
Nelson L. Michael ◽  
Steven A. Herman ◽  
Shirley Kwok ◽  
Kimberly Dreyer ◽  
June Wang ◽  
...  

Accurate determination of plasma human immunodeficiency virus type 1 (HIV-1) RNA levels is critical for the effective management of HIV-1 disease. The AMPLICOR HIV-1 MONITOR Test, a reverse transcription-PCR-based test for quantification of HIV-1 RNA in plasma, was developed when little sequence information on HIV-1 isolates from outside North America was available. It has since become apparent that many non-subtype B isolates, particularly subtypes A and E, are detected inefficiently by the test. We describe here the AMPLICOR HIV-1 MONITOR Test, version 1.5, an upgraded test developed to minimize subtype-related variation. We also developed a panel of HIV-1 standards containing 30 HIV-1 isolates of subtypes A through G. The virus particle concentration of each cultured viral stock was standardized by electron microscopic virus particle counting. We used this panel to determine the performance of the original AMPLICOR HIV-1 MONITOR Test and version 1.5 of the test with HIV-1 subtypes A through G. The original test underestimated the concentration of HIV-1 subtype A, E, F, and G RNA by 10-fold or more, whereas version of the 1.5 test yielded equivalent quantification of HIV-1 RNA regardless of the subtype. In light of the increasing intermixing of HIV-1 subtypes worldwide, standardization of PCR-based tests against well-characterized viral isolates representing the full range of HIV-1 diversity will be essential for the continued utility of these important clinical management tools.

1998 ◽  
Vol 72 (11) ◽  
pp. 9337-9344 ◽  
Author(s):  
Yi-jun Zhang ◽  
Tatjana Dragic ◽  
Yunzhen Cao ◽  
Leondios Kostrikis ◽  
Douglas S. Kwon ◽  
...  

ABSTRACT We have tested a panel of pediatric and adult human immunodeficiency virus type 1 (HIV-1) primary isolates for the ability to employ the following proteins as coreceptors during viral entry: CCR1, CCR2b, CCR3, CCR4, CCR5, CCR8, CXCR4, Bonzo, BOB, GPR1, V28, US28, and APJ. Most non-syncytium-inducing isolates could utilize only CCR5. All syncytium-inducing viruses used CXCR4, some also employed V28, and one (DH123) used CCR8 and APJ as well. A longitudinal series of HIV-1 subtype B isolates from an infected infant and its mother utilized Bonzo efficiently, as well as CCR5. The maternal isolates, which were syncytium inducing, also used CXCR4, CCR8, V28, and APJ.


2004 ◽  
Vol 78 (13) ◽  
pp. 7279-7283 ◽  
Author(s):  
Manish Sagar ◽  
Erin Kirkegaard ◽  
E. Michelle Long ◽  
Connie Celum ◽  
Susan Buchbinder ◽  
...  

ABSTRACT African women frequently acquire several genetically distinct human immunodeficiency virus type 1 (HIV-1) variants from a heterosexual partner, whereas the acquisition of multiple variants appears to be rare in men. To determine whether newly infected individuals in other risk groups acquire genetically diverse viruses, we examined the viral envelope sequences in plasma samples from 13 women and 4 men from the United States infected with subtype B viruses and 10 men from Kenya infected with non-subtype B viruses. HIV-1 envelope sequences differed by more than 2% in three U.S. women, one U.S. man, and one Kenyan man near the time of seroconversion. These findings suggest that early HIV-1 genetic diversity is not exclusive to women from Africa or to infection with any particular HIV-1 subtype.


2009 ◽  
Vol 83 (19) ◽  
pp. 10269-10274 ◽  
Author(s):  
Anne Piantadosi ◽  
Dana Panteleeff ◽  
Catherine A. Blish ◽  
Jared M. Baeten ◽  
Walter Jaoko ◽  
...  

ABSTRACT The determinants of a broad neutralizing antibody (NAb) response and its effect on human immunodeficiency virus type 1 (HIV-1) disease progression are not well defined, partly because most prior studies of a broad NAb response were cross-sectional. We examined correlates of NAb response breadth among 70 HIV-infected, antiretroviral-naïve Kenyan women from a longitudinal seroincident cohort. NAb response breadth was measured 5 years after infection against five subtype A viruses and one subtype B virus. Greater NAb response breadth was associated with a higher viral load set point and greater HIV-1 env diversity early in infection. However, greater NAb response breadth was not associated with a delayed time to a CD4+ T-cell count of <200, antiretroviral therapy, or death. Thus, a broad NAb response results from a high level of antigenic stimulation early in infection, which likely accounts for prior observations that greater NAb response breadth is associated with a higher viral load later in infection.


2012 ◽  
Vol 93 (12) ◽  
pp. 2625-2634 ◽  
Author(s):  
Elena Capel ◽  
Glòria Martrus ◽  
Mariona Parera ◽  
Bonaventura Clotet ◽  
Miguel Angel Martínez

The rapid spread of human immunodeficiency virus type 1 (HIV-1) in humans has been accompanied by continuous extensive genetic diversification of the virus. The aim of this study was to investigate the impact of HIV-1 diversification on HIV-1 replication capacity (RC) and mutational robustness. Thirty-three HIV-1 protease sequences were amplified from three groups of viruses: two naïve sample groups isolated 15 years apart plus a third group of protease inhibitor-(PI) resistant samples. The amplified proteases were recombined with an HXB2 infectious clone and RC was determined in MT-4 cells. RC was also measured in these three groups after random mutagenesis in vitro using error-prone PCR. No significant RC differences were observed between recombinant viruses from either early or recent naïve isolates (P = 0.5729), even though the proteases from the recent isolates had significantly lower sequence conservation scores compared with a subtype B ancestral sequence (P<0.0001). Randomly mutated recombinant viruses from the three groups exhibited significantly lower RC values than the corresponding wild-type viruses (P<0.0001). There was no significant difference regarding viral infectivity reduction between viruses carrying randomly mutated naïve proteases from early or recent sample isolates (P = 0.8035). Interestingly, a significantly greater loss of RC was observed in the PI-resistant protease group (P = 0.0400). These results demonstrate that protease sequence diversification has not affected HIV-1 RC or protease robustness and indicate that proteases carrying PI resistance substitutions are less robust than naïve proteases.


2005 ◽  
Vol 79 (10) ◽  
pp. 6089-6101 ◽  
Author(s):  
Bruce K. Brown ◽  
Janice M. Darden ◽  
Sodsai Tovanabutra ◽  
Tamara Oblander ◽  
Julie Frost ◽  
...  

ABSTRACT A critical priority for human immunodeficiency virus type 1 (HIV-1) vaccine development is standardization of reagents and assays for evaluation of immune responses elicited by candidate vaccines. To provide a panel of viral reagents from multiple vaccine trial sites, 60 international HIV-1 isolates were expanded in peripheral blood mononuclear cells and characterized both genetically and biologically. Ten isolates each from clades A, B, C, and D and 10 isolates each from CRF01_AE and CRF02_AG were prepared from individuals whose HIV-1 infection was evaluated by complete genome sequencing. The main criterion for selection was that the candidate isolate was pure clade or pure circulating recombinant. After expansion in culture, the complete envelope (gp160) of each isolate was verified by sequencing. The 50% tissue culture infectious dose and p24 antigen concentration for each viral stock were determined; no correlation between these two biologic parameters was found. Syncytium formation in MT-2 cells and CCR5 or CXCR4 coreceptor usage were determined for all isolates. Isolates were also screened for neutralization by soluble CD4, a cocktail of monoclonal antibodies, and a pool of HIV-1-positive patient sera. The panel consists of 49 nonsyncytium-inducing isolates that use CCR5 as a major coreceptor and 11 syncytium-inducing isolates that use only CXCR4 or both coreceptors. Neutralization profiles suggest that the panel contains both neutralization-sensitive and -resistant isolates. This collection of HIV-1 isolates represents the six major globally prevalent strains, is exceptionally large and well characterized, and provides an important resource for standardization of immunogenicity assessment in HIV-1 vaccine trials.


2008 ◽  
Vol 82 (23) ◽  
pp. 11651-11668 ◽  
Author(s):  
James M. Binley ◽  
Elizabeth A. Lybarger ◽  
Emma T. Crooks ◽  
Michael S. Seaman ◽  
Elin Gray ◽  
...  

ABSTRACT Identifying the viral epitopes targeted by broad neutralizing antibodies (NAbs) that sometimes develop in human immunodeficiency virus type 1 (HIV-1)-infected subjects should assist in the design of vaccines to elicit similar responses. Here, we investigated the activities of a panel of 24 broadly neutralizing plasmas from subtype B- and C-infected donors using a series of complementary mapping methods, focusing mostly on JR-FL as a prototype subtype B primary isolate. Adsorption with gp120 immobilized on beads revealed that an often large but variable fraction of plasma neutralization was directed to gp120 and that in some cases, neutralization was largely mediated by CD4 binding site (CD4bs) Abs. The results of a native polyacrylamide gel electrophoresis assay using JR-FL trimers further suggested that half of the subtype B and a smaller fraction of subtype C plasmas contained a significant proportion of NAbs directed to the CD4bs. Anti-gp41 neutralizing activity was detected in several plasmas of both subtypes, but in all but one case, constituted only a minor fraction of the overall neutralization activity. Assessment of the activities of the subtype B plasmas against chimeric HIV-2 viruses bearing various fragments of the membrane proximal external region (MPER) of HIV-1 gp41 revealed mixed patterns, implying that MPER neutralization was not dominated by any single specificity akin to known MPER-specific monoclonal Abs. V3 and 2G12-like NAbs appeared to make little or no contribution to JR-FL neutralization titers. Overall, we observed significant titers of anti-CD4bs NAbs in several plasmas, but approximately two-thirds of the neutralizing activity remained undefined, suggesting the existence of NAbs with specificities unlike any characterized to date.


2006 ◽  
Vol 80 (3) ◽  
pp. 1311-1320 ◽  
Author(s):  
Eduardo O'Neill ◽  
Lillian S. Kuo ◽  
John F. Krisko ◽  
Diana R. Tomchick ◽  
J. Victor Garcia ◽  
...  

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) early gene product Nef is a multifunctional protein that alters numerous pathways of T-cell function, including endocytosis, signal transduction, vesicular trafficking, and immune modulation, and is a major determinant of pathogenesis. Individual Nef functions include PAK-2 activation, CD4 downregulation, major histocompatibility complex (MHC) class I downregulation, and enhancement of viral particle infectivity. How Nef accomplishes its multiple tasks presents a difficult problem of mechanistic analysis because of the complications associated with multiple, overlapping functional domains in the context of significant sequence variability. To address these issues we determined the conservation of each Nef residue based on 1,643 subtype B Nef sequences. Mutational analysis based on conservative substitutions and Nef sequence data allowed us to search for amino acids on the surface of Nef that are specifically required for PAK-2 activation. We found residues 85, 89, and 191 to be highly significant determinants for Nef's PAK-2 activation function but functionally unlinked to CD4 and MHC class I downregulation or enhancement of infectivity. These residues are not conserved across HIV-1 subtypes but are confined to separate sets of surface elements within a subtype. Thus, L85/H89/F191 and F85/F89/R191 are dominant in subtype B and subtype E or C, respectively. Our results provide support for developing subtype-specific interventions in HIV-1 disease.


2003 ◽  
Vol 47 (7) ◽  
pp. 2376-2379 ◽  
Author(s):  
Karidia Diallo ◽  
Bluma Brenner ◽  
Maureen Oliveira ◽  
Daniela Moisi ◽  
Mervi Detorio ◽  
...  

ABSTRACT The M184V substitution in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT), encoding high-level resistance to lamivudine (3TC), results in decreased HIV-1 replicative capacity, diminished RT processivity, and increased RT fidelity in biochemical assays. We assessed the effect of M184V on the development of resistance to the nonnucleoside RT inhibitors efavirenz (EFV) and nevirapine, and to the protease inhibitor amprenavir (APV) in tissue culture. Genotypic analysis revealed differences in EFV resistance-conferring mutations in subtype B (K103N) versus subtype C (V106 M), and the appearance of both was significantly delayed in the M184V-containing variants compared with the wild type (WT). Similarly, there was a marked delay in the emergence of mutations associated with APV resistance (I54 M/L/V) in subtype B viruses harboring M184V compared with paired WT viral isolates.


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