scholarly journals The Evolution of Regulatory Elements in the Emerging Promoter-Variant Strains of HIV-1 Subtype C

2021 ◽  
Vol 12 ◽  
Author(s):  
Disha Bhange ◽  
Nityanand Prasad ◽  
Swati Singh ◽  
Harshit Kumar Prajapati ◽  
Shesh Prakash Maurya ◽  
...  

In a multicentric, observational, investigator-blinded, and longitudinal clinical study of 764 ART-naïve subjects, we identified nine different promoter variant strains of HIV-1 subtype C (HIV-1C) emerging in the Indian population, with some of these variants being reported for the first time. Unlike several previous studies, our work here focuses on the evolving viral regulatory elements, not the coding sequences. The emerging viral strains contain additional copies of the existing transcription factor binding sites (TFBS), including TCF-1α/LEF-1, RBEIII, AP-1, and NF-κB, created by sequence duplication. The additional TFBS are genetically diverse and may blur the distinction between the modulatory region of the promoter and the viral enhancer. In a follow-up analysis, we found trends, but no significant associations between any specific variant promoter and prognostic markers, probably because the emerging viral strains might not have established mono infections yet. Illumina sequencing of four clinical samples containing a coinfection indicated the domination of one strain over the other and establishing a stable ratio with the second strain at the follow-up time points. Since a single promoter regulates viral gene expression and constitutes the master regulatory circuit with Tat, the acquisition of additional and variant copies of the TFBS may significantly impact viral latency and latent reservoir characteristics. Further studies are urgently warranted to understand how the diverse TFBS profiles of the viral promoter may modulate the characteristics of the latent reservoir, especially following the initiation of antiretroviral therapy.

2021 ◽  
Author(s):  
Disha Bhange ◽  
Nityanand Prasad ◽  
Swati Singh ◽  
Harshit Kumar Prajapati ◽  
Shesh Prakash Maurya ◽  
...  

AbstractIn a multicentric, observational, investigator-blinded, and longitudinal clinical study of 764 ART-naïve subjects, we identified nine different promoter-variant strains of HIV-1 subtype C (HIV-1C) emerging in the Indian population, with some of these variants being reported for the first time. Unlike several previous studies, our work here focuses on the evolving viral regulatory elements, not coding sequences. The emerging viral strains contain additional copies of the existing transcription factor binding sites (TFBS), including TCF-1α/LEF-1, RBEIII, AP-1, and NF-κB, created by sequence duplication. The additional TFBS are genetically diverse and may blur the distinction between the modulatory region of the promoter and the viral enhancer. In a follow-up analysis, we found trends, but not significant associations between any specific variant promoter and prognostic markers, probably because the emerging viral strains might not have established mono infections yet. Illumina sequencing of four clinical samples containing a co-infection indicated the domination of one strain over the other and establishing a stable ratio with the second strain at the follow-up time-points. Since a single promoter regulates viral gene expression and constitutes the master regulatory circuit with Tat, the acquisition of additional and variant copies of the TFBS may significantly impact viral latency and latent reservoir characteristics. Further studies are urgently warranted to understand how the diverse TFBS profiles of the viral promoter may modulate the characteristics of the latent reservoir, especially following the initiation of antiretroviral therapy.Significance StatementA unique conglomeration of TFBS enables the HIV-1 promoter to accomplish two diametrically opposite functions – transcriptional activation and transcriptional silencing. The various phases of viral latency - establishment, maintenance, and reversal - collectively determine the replication fitness of individual viral strains. A profound variation in the TFBS composition of the viral promoter may significantly alter the viral latency properties and the latent reservoir characteristics. Although the duplication of certain TFBS remains a quality unique to HIV-1C, the high-level genetic recombination of HIV-1 may promote the transfer of such molecular properties to the other HIV-1 subtypes. The emergence of several promoter-variant viral strains may make the task of a ‘functional cure’ more challenging in HIV-1C.


Retrovirology ◽  
2009 ◽  
Vol 6 (S2) ◽  
Author(s):  
Mahesh Bachu ◽  
Rajesh V Murali ◽  
Anil MHKH Babu ◽  
Venkat SRK Yedavalli ◽  
Kuan-Teh Jeang ◽  
...  

Retrovirology ◽  
2013 ◽  
Vol 10 (S1) ◽  
Author(s):  
Anjali Verma ◽  
Pavithra Rajgopalan ◽  
Rishikesh Lotke ◽  
Saihitha Veerapaneni ◽  
Mahesh Bachu ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-28 ◽  
Author(s):  
Luna Li ◽  
Satinder Dahiya ◽  
Sandhya Kortagere ◽  
Benjamas Aiamkitsumrit ◽  
David Cunningham ◽  
...  

The human immunodeficiency virus type 1 (HIV-1) promoter or long-terminal repeat (LTR) regulates viral gene expression by interacting with multiple viral and host factors. The viral transactivator protein Tat plays an important role in transcriptional activation of HIV-1 gene expression. Functional domains of Tat and its interaction with transactivation response element RNA and cellular transcription factors have been examined. Genetic variation withintatof different HIV-1 subtypes has been shown to affect the interaction of the viral transactivator with cellular and/or viral proteins, influencing the overall level of transcriptional activation as well as its action as a neurotoxic protein. Consequently, the genetic variability withintatmay impact the molecular architecture of functional domains of the Tat protein that may impact HIV pathogenesis and disease. Tat as a therapeutic target for anti-HIV drugs has also been discussed.


2017 ◽  
Vol 3 ◽  
pp. 8
Author(s):  
R. Verdikt ◽  
L. Colin ◽  
C. Vanhulle ◽  
B. Van Driessche ◽  
A. Kula ◽  
...  

Virology ◽  
1990 ◽  
Vol 177 (1) ◽  
pp. 380-383 ◽  
Author(s):  
V.S. Kalyanaraman ◽  
V. Rodriguez ◽  
S. Josephs ◽  
R.C. Gallo ◽  
M.G. Sarngadharan

10.1038/nm880 ◽  
2003 ◽  
Vol 9 (6) ◽  
pp. 727-728 ◽  
Author(s):  
Janet D Siliciano ◽  
Joleen Kajdas ◽  
Diana Finzi ◽  
Thomas C Quinn ◽  
Karen Chadwick ◽  
...  

Pathogens ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 125 ◽  
Author(s):  
Magdalena Weidner-Glunde ◽  
Ewa Kruminis-Kaszkiel ◽  
Mamata Savanagouder

Latency establishment is the hallmark feature of herpesviruses, a group of viruses, of which nine are known to infect humans. They have co-evolved alongside their hosts, and mastered manipulation of cellular pathways and tweaking various processes to their advantage. As a result, they are very well adapted to persistence. The members of the three subfamilies belonging to the family Herpesviridae differ with regard to cell tropism, target cells for the latent reservoir, and characteristics of the infection. The mechanisms governing the latent state also seem quite different. Our knowledge about latency is most complete for the gammaherpesviruses due to previously missing adequate latency models for the alpha and beta-herpesviruses. Nevertheless, with advances in cell biology and the availability of appropriate cell-culture and animal models, the common features of the latency in the different subfamilies began to emerge. Three criteria have been set forth to define latency and differentiate it from persistent or abortive infection: 1) persistence of the viral genome, 2) limited viral gene expression with no viral particle production, and 3) the ability to reactivate to a lytic cycle. This review discusses these criteria for each of the subfamilies and highlights the common strategies adopted by herpesviruses to establish latency.


2019 ◽  
Vol 26 (2) ◽  
pp. 217-227.e6 ◽  
Author(s):  
David G. Courtney ◽  
Kevin Tsai ◽  
Hal P. Bogerd ◽  
Edward M. Kennedy ◽  
Brittany A. Law ◽  
...  

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