scholarly journals A7 Co-receptor tropism determined by genotypic assay in HIV-1 non-B subtypes circulating in Cuba: Implications for pathogenesis and Maraviroc resistance

2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
M Méndez ◽  
V Kourí ◽  
L Pérez ◽  
Y Alemán ◽  
Y Martínez ◽  
...  

Abstract The V3 loop of the HIV-1 envelope (env) gene is involved in binding to the chemokine receptors CCR5 and CXCR4, thus determining viral tropism. With the aim of genetically characterizing the C2V3 env region of HIV-1 samples from Cuban patients, naive to Maraviroc (MVC) therapy, 115 plasma samples were taken in the period of 2014–6 and analyzed by sequencing of the C2V3 region. HIV-1 subtyping was performed using COMET V.2 and Rega subtyping toolV.3 software. Subtypes were confirmed by phylogenetic analyses using Mega-6. Prediction of co-receptor tropism was performed using the geno2pheno algorithm. The viral mutations associated to MVC resistance were analyzed, as well as the association of the subtype with clinical, epidemiological, virological, and immunological variables. The subtypes detected using the C2V3 region were CRF20, 23, 24_BG (35 patients, 30.4%); Subtype B (33 patients, 28.7%); CRF19_cpx (30 patients, 26.1%); CRF18_cpx (10 patients, 8.7%); and others (7 patients, 6.1%). Overall, 60 per cent of the viruses exhibited R5 phenotype, 14.8 per cent were R5X4 and 25.2 per cent were X4. Interestingly, CRF19_cpx virus was associated with having phenotype X4 [46.7%, P = 0.0047, odds ratio (OR): 3.96, 95% confidence interval (95% CI): 1.59–9.84], with infection in young individuals (39.1%, P = 0.025, OR: 3,548; 95% CI: 1,136–11,077) and with higher values of viral load (P ≤ 0.05). The comparison of the amino acid sequences of the V3 loop showed differences between the B and non-B subtypes (P = 0.0001). Mutations reported to be associated with MVC resistance, were detected in 75.7 per cent of the samples, in positions 11 (6.1%), 13 (49.6%), 25 (6.1%), 316 (7.0%), 323 (11.3%), and 319 (3.5%) of Gp120, particularly in the recombinant forms CRF19_cpx and CRF_BGs. HIV variants that use the CXCR4 co-receptor were associated with more than 10 years of diagnosis, with older individuals, in the AIDS stage, with low CD4 counts and higher viral load levels (P < 0.05). The results support the hypothesis previously stated that CRF19_cpx viruses could be more pathogenic and would have limitations for the use of MVC. The high rate of mutations associated to MVC among non-B Cuban subtypes should be further studied.

2020 ◽  
Vol 18 (3) ◽  
pp. 210-218
Author(s):  
Guolong Yu ◽  
Yan Li ◽  
Xuhe Huang ◽  
Pingping Zhou ◽  
Jin Yan ◽  
...  

Background: HIV-1 CRF55_01B was first reported in 2013. At present, no report is available regarding this new clade’s polymorphisms in its functionally critical regions protease and reverse transcriptase. Objective: To identify the diversity difference in protease and reverse transcriptase between CRF55_01B and its parental clades CRF01_AE and subtype B; and to investigate CRF55_01B’s drug resistance mutations associated with the protease inhibition and reverse transcriptase inhibition. Methods: HIV-1 RNA was extracted from plasma derived from a MSM population. The reverse transcription and nested PCR amplification were performed following our in-house PCR procedure. Genotyping and drug resistant-associated mutations and polymorphisms were identified based on polygenetic analyses and the usage of the HIV Drug Resistance Database, respectively. Results: A total of 9.24 % of the identified CRF55_01B sequences bear the primary drug resistance. CRF55_01B contains polymorphisms I13I/V, G16E and E35D that differ from those in CRF01_AE. Among the 11 polymorphisms in the RT region, seven were statistically different from CRF01_AE’s. Another three polymorphisms, R211K (98.3%), F214L (98.3%), and V245A/E (98.3 %.), were identified in the RT region and they all were statistically different with that of the subtype B. The V179E/D mutation, responsible for 100% potential low-level drug resistance, was found in all CRF55_01B sequences. Lastly, the phylogenetic analyses demonstrated 18 distinct clusters that account for 35% of the samples. Conclusions: CRF55_01B’s pol has different genetic diversity comparing to its counterpart in CRF55_01B’s parental clades. CRF55_01B has a high primary drug resistance presence and the V179E/D mutation may confer more vulnerability to drug resistance.


2020 ◽  
Vol 75 (6) ◽  
pp. 1567-1574
Author(s):  
Daniela Sánchez ◽  
Solange Arazi Caillaud ◽  
Ines Zapiola ◽  
Silvina Fernandez Giuliano ◽  
Rosa Bologna ◽  
...  

Abstract Background Current knowledge on HIV-1 resistance to integrase inhibitors (INIs) is based mostly on subtype B strains. This contrasts with the increasing use of INIs in low- and middle-income countries, where non-B subtypes predominate. Materials and methods HIV-1 drug resistance genotyping was performed in 30 HIV-1-infected individuals undergoing virological failure to raltegravir. Drug resistance mutations (DRMs) and HIV-1 subtype were characterized using Stanford HIVdb and phylogenetic analyses. Results Of the 30 integrase (IN) sequences, 14 were characterized as subtype F (47%), 8 as subtype B (27%), 7 as BF recombinants (23%) and 1 as a putative CRF05_DF (3%). In 25 cases (83%), protease and reverse transcriptase (PR-RT) sequences from the same individuals confirmed the presence of different BF recombinants. Stanford HIVdb genotyping was concordant with phylogenetic inference in 70% of IN and 60% of PR-RT sequences. INI DRMs differed between B and F IN subtypes, with Q148K/R/H, G140S and E138K/A being more prevalent in subtype B (63% versus 0%, P = 0.0021; 50% versus 0%, P = 0.0096; and 50% versus 0%, P = 0.0096, respectively). These differences were independent of the time on raltegravir therapy or viral load at the time of genotyping. INI DRMs in subtype F IN genomes predicted a lower level of resistance to raltegravir and no cross-resistance to second-generation INIs. Conclusions Alternative resistance pathways to raltegravir develop in subtypes B and F IN genomes, with implications for clinical practice. Evaluating the role of HIV-1 subtype in development and persistence of mutations that confer resistance to INIs will be important to improve algorithms for resistance testing and optimize the use of INIs.


2010 ◽  
Vol 84 (7) ◽  
pp. 3147-3161 ◽  
Author(s):  
Shi-Hua Xiang ◽  
Andrés Finzi ◽  
Beatriz Pacheco ◽  
Kevin Alexander ◽  
Wen Yuan ◽  
...  

ABSTRACT Human immunodeficiency virus (HIV-1) entry into cells is mediated by a trimeric complex consisting of noncovalently associated gp120 (exterior) and gp41 (transmembrane) envelope glycoproteins. The binding of gp120 to receptors on the target cell alters the gp120-gp41 relationship and activates the membrane-fusing capacity of gp41. Interaction of gp120 with the primary receptor, CD4, results in the exposure of the gp120 third variable (V3) loop, which contributes to binding the CCR5 or CXCR4 chemokine receptors. We show here that insertions in the V3 stem or polar substitutions in a conserved hydrophobic patch near the V3 tip result in decreased gp120-gp41 association (in the unliganded state) and decreased chemokine receptor binding (in the CD4-bound state). Subunit association and syncytium-forming ability of the envelope glycoproteins from primary HIV-1 isolates were disrupted more by V3 changes than those of laboratory-adapted HIV-1 envelope glycoproteins. Changes in the gp120 β2, β19, β20, and β21 strands, which evidence suggests are proximal to the V3 loop in unliganded gp120, also resulted in decreased gp120-gp41 association. Thus, a gp120 element composed of the V3 loop and adjacent beta strands contributes to quaternary interactions that stabilize the unliganded trimer. CD4 binding dismantles this element, altering the gp120-gp41 relationship and rendering the hydrophobic patch in the V3 tip available for chemokine receptor binding.


1999 ◽  
Vol 37 (1) ◽  
pp. 110-116 ◽  
Author(s):  
K. Triques ◽  
J. Coste ◽  
J. L. Perret ◽  
C. Segarra ◽  
E. Mpoudi ◽  
...  

Three versions of a commercial human immunodeficiency virus (HIV) type 1 (HIV-1) load test (the AMPLICOR HIV-1 MONITOR Test versions 1.0, 1.0+, and 1.5; Roche Diagnostics, Branchburg, N.J.) were evaluated for their ability to detect and quantify HIV-1 RNA of different genetic subtypes. Plasma samples from 96 patients infected with various subtypes of HIV-1 (55 patients infected with subtype A, 9 with subtype B, 21 with subtype C, 2 with subtype D, 7 with subtype E, and 2 with subtype G) and cultured virus from 29 HIV-1 reference strains (3 of subtype A, 6 of subtype B, 5 of subtype C, 3 of subtype D, 8 of subtype E, 3 of subtype F, and 1 of subtype G) were tested. Detection of subtypes A and E was significantly improved with versions 1.0+ and 1.5 compared to that with version 1.0, whereas detection of subtypes B, C, D, and G was equivalent with the three versions. Versions 1.0, 1.0+, and 1.5 detected 65, 98, and 100% of the subtype A-infected samples from patients, respectively, and 71, 100, and 100% of the subtype E-infected samples from patients, respectively. Version 1.5 yielded a significant increase in viral load for samples infected with subtypes A and E (greater than 1 log10 HIV RNA copies/ml). For samples infected with subtype B, C, and D and tested with version 1.5, only a slight increase in viral load was observed (<0.5 log10). We also evaluated a prototype automated version of the test that uses the same PCR primers as version 1.5. The results with the prototype automated test were highly correlated with those of the version 1.5 test for all subtypes, but were lower overall. The AMPLICOR HIV-1 MONITOR Test, version 1.5, yielded accurate measurement of the HIV load for all HIV-1 subtypes tested, which should allow the test to be used to assess disease prognosis and response to antiretroviral treatment in patients infected with a group M HIV-1 subtype.


2015 ◽  
Vol 90 (2) ◽  
pp. 636-649 ◽  
Author(s):  
Susan Zolla-Pazner ◽  
Sandra Sharpe Cohen ◽  
David Boyd ◽  
Xiang-Peng Kong ◽  
Michael Seaman ◽  
...  

ABSTRACTAntibodies (Abs) specific for the V3 loop of the HIV-1 gp120 envelope neutralize most tier 1 and many tier 2 viruses and are present in essentially all HIV-infected individuals as well as immunized humans and animals. Vaccine-induced V3 Abs are associated with reduced HIV infection rates in humans and affect the nature of transmitted viruses in infected vaccinees, despite the fact that V3 is often occluded in the envelope trimer. Here, we link structural and experimental data showing how conformational alterations of the envelope trimer render viruses exceptionally sensitive to V3 Abs. The experiments interrogated the neutralization sensitivity of pseudoviruses with single amino acid mutations in various regions of gp120 that were predicted to alter packing of the V3 loop in the Env trimer. The results indicate that the V3 loop is metastable in the envelope trimer on the virion surface, flickering between states in which V3 is either occluded or available for binding to chemokine receptors (leading to infection) and to V3 Abs (leading to virus neutralization). The spring-loaded V3 in the envelope trimer is easily released by disruption of the stability of the V3 pocket in the unliganded trimer or disruption of favorable V3/pocket interactions. Formation of the V3 pocket requires appropriate positioning of the V1V2 domain, which is, in turn, dependent on the conformation of the bridging sheet and on the stability of the V1V2 B-C strand-connecting loop.IMPORTANCEThe levels of antibodies to the third variable region (V3) of the HIV envelope protein correlate with reduced HIV infection rates. Previous studies showed that V3 is often occluded, as it sits in a pocket of the envelope trimer on the surface of virions; however, the trimer is flexible, allowing occluded portions of the envelope (like V3) to flicker into an exposed position that binds antibodies. Here we provide a systematic interrogation of mechanisms by which single amino acid changes in various regions of gp120 (i) render viruses sensitive to neutralization by V3 antibodies, (ii) result in altered packing of the V3 loop, and (iii) activate an open conformation that exposes V3 to the effects of V3 Abs. Taken together, these and previous studies explain how V3 antibodies can protect against HIV-1 infection and why they should be one of the targets of vaccine-induced antibodies.


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.


2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S424-S424
Author(s):  
Ioannis Demetriades

Abstract Background A molecular epidemiology study of HIV-1 infection was conducted in 100 HIV-1 diagnosed and untreated patients in Cyprus representing 65.4 percent of all the reported HIV-1 infections in Cyprus between 2010 and 2012. Methods Eighty-two patients were newly diagnosed (genotypic drug resistance testing within six months from diagnosis), and 18 patients were HIV-1 diagnosed for a longer period or the diagnosis date was unknown. Results Phylogenetic trees of the pol sequences obtained in this study with reference sequences indicated that subtypes B and A1 were the most common subtypes present and accounted for 41.0 and 19.0% respectively, followed by subtype C (7.0%), F1 (8.0%), CRF02_AG (4.0%), A2 (2.0%), other CRFs (7.0%) and unknown recombinant forms, URFs (12%). Most of newly-diagnosed study subjects were Cypriots (63%), males (78%) with median age 39 (Interquartile Range, IQR 33–48) reporting having sex with other men, MSM (51%). Conclusion A high rate of clustered transmission of subtype B drug-sensitive strains to reverse transcriptase and protease inhibitors was observed among MSM. Twenty-eight out of forty-one MSM study subjects (68.0%) infected were implicated in five transmission clusters, two of which are subtype A1 and three subtype B strains. The two largest MSM subtype B clusters included nine and eight Cypriot men, respectively, living in all major cities in Cyprus. There were only three newly diagnosed patients with transmitted drug resistant HIV-1 strains, one study subject from the United Kingdom infected with subtype B strain and one from Romania with subtype A2 strain, both with the PI drug resistance mutation M46L and one patient from Greece with subtype A1 strain with the NNRTI drug resistance mutation K103N. Disclosures All authors: No reported disclosures.


2010 ◽  
Vol 41 (3) ◽  
pp. 720-728 ◽  
Author(s):  
Rejane-Maria Tomasini-Grotto ◽  
Brigitte Montes ◽  
Denise Triglia ◽  
Carla Torres- Braconi ◽  
Juliana Aliano-Block ◽  
...  
Keyword(s):  
V3 Loop ◽  

2013 ◽  
Vol 4 ◽  
pp. VRT.S12677 ◽  
Author(s):  
Georgina N. Odaibo ◽  
Isaac F. Adewole ◽  
David O. Olaleye

Plasma HIV-1 RNA concentration, or viral load, is an indication of the magnitude of virus replication and largely correlates with disease progression in an infected person. It is a very useful guide for initiation of therapy and monitoring of response to antiretroviral drugs. Although the majority of patients who are not on antiretroviral therapy (ART) have a high viral load, a small proportion of ART naive patients are known to maintain low levels or even undetectable viral load levels. In this study, we determined the rate of undetectable HIV-1 RNA among ART naive HIV positive patients who presented for treatment at the University College Hospital (UCH), Ibadan, Nigeria from 2005 to 2011. Baseline viral load and CD4 lymphocyte cell counts of 14,662 HIV positive drug naive individuals were determined using the Roche Amplicor version 1.5 and Partec easy count kit, respectively. The detection limits of the viral load assay are 400 copies/mL and 750,000 copies/mL for lower and upper levels, respectively. A total of 1,399 of the 14,662 (9.5%) HIV-1 positive drug naive individuals had undetectable viral load during the study period. In addition, the rate of non-detectable viral load increased over the years. The mean CD4 counts among HIV-1 infected individuals with detectable viral load (266 cells/μL; range = 1 to 2,699 cells/μL) was lower than in patients with undetectable viral load (557 cells/μL; range = 1 to 3,102 cells/μL). About 10% of HIV-1 infected persons in our study population had undetectable viral load using the Roche Amplicor version 1.5.


2002 ◽  
Vol 76 (21) ◽  
pp. 10674-10684 ◽  
Author(s):  
Shan-Lu Liu ◽  
John E. Mittler ◽  
David C. Nickle ◽  
Thera M. Mulvania ◽  
Daniel Shriner ◽  
...  

ABSTRACT Although human immunodeficiency virus type 1 (HIV-1) recombinants have been found with high frequency, little is known about the forces that select for these viruses or their importance to pathogenesis. Here we document the emergence and dynamics of 11 distinct HIV-1 recombinants in a man who was infected with two subtype B HIV-1 strains and progressed rapidly to AIDS without developing substantial cellular or humoral immune responses. Although numerous frequency oscillations were observed, a single recombinant lineage eventually came to dominate the population. Numerical simulations indicate that the successive recombinant forms displaced each other too rapidly to be explained by any simple model of random genetic drift or sampling variation. All of the recombinants, including several resulting from independent recombination events, possessed the same sequence motif in the V3 loop, suggesting intense selection on this segment of the viral envelope protein. The outgrowth of the predominant V3 loop recombinants was not, however, associated with changes in coreceptor utilization. The final variant was instead notable for having lost 3 of 14 potential glycosylation sites. We also observed high ratios of synonymous-to-nonsynonymous nucleotide changes—suggestive of purifying selection—in all viral populations, with particularly high ratios in newly arising recombinants. Our study, therefore, illustrates the unusual and important patterns of viral adaptation that can occur in a patient with weak immune responses. Although it is hard to tease apart cause and effect in a single patient, the correlation with disease progression in this patient suggests that recombination between divergent viruses, with its ability to create chimeras with increased fitness, can accelerate progression to AIDS.


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