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MedRxiv : the Preprint Server For... Jun 2024Persisting HIV reservoir viruses in resting CD4 T cells and other cellular subsets are the main barrier to cure efforts. Antiretroviral therapy (ART) intensification by...
BACKGROUND
Persisting HIV reservoir viruses in resting CD4 T cells and other cellular subsets are the main barrier to cure efforts. Antiretroviral therapy (ART) intensification by early initiation has been shown to enable post-treatment viral control in some cases but the underlying mechanisms are not fully understood. We hypothesized that ART initiated during the hyperacute phase of infection before peak will affect the size, decay dynamics and landscape characteristics of HIV-1 subtype C viral reservoirs.
METHODS
We studied 35 women at high risk of infection from Durban, South Africa identified with hyperacute HIV infection by twice weekly testing for plasma HIV-1 RNA. Study participants included 11 who started ART at a median of 456 (297-1203) days post onset of viremia (DPOV), and 24 who started ART at a median of 1 (1-3) DPOV. We used peripheral blood mononuclear cells (PBMC) to measure total HIV-1 DNA by ddPCR and to sequence reservoir viral genomes by full length individual proviral sequencing (FLIP-seq) from onset of detection of HIV up to 1 year post treatment initiation.
RESULTS
Whereas ART in hyperacute infection blunted peak viremia compared to untreated individuals (p<0.0001), there was no difference in total HIV-1 DNA measured contemporaneously (p=0.104). There was a steady decline of total HIV DNA in early treated persons over 1 year of ART (p=0.0004), with no significant change observed in the late treated group. Total HIV-1 DNA after one year of treatment was lower in the early treated compared to the late treated group (p=0.02). Generation of 697 single viral genome sequences revealed a difference in the longitudinal proviral genetic landscape over one year between untreated, late treated, and early treated infection: the relative contribution of intact genomes to the total pool of HIV-1 DNA after 1 year was higher in untreated infection (31%) compared to late treated (14%) and early treated infection (0%). Treatment initiated in both late and early infection resulted in a more rapid decay of intact (13% and 51% per month) versus defective (2% and 35% per month) viral genomes. However, intact genomes were still observed one year post chronic treatment initiation in contrast to early treatment where intact genomes were no longer detectable. Moreover, early ART reduced phylogenetic diversity of intact genomes and limited the seeding and persistence of cytotoxic T lymphocyte immune escape variants in the reservoir.
CONCLUSIONS
Overall, our results show that whereas ART initiated in hyperacute HIV-1 subtype C infection did not impact reservoir seeding, it was nevertheless associated with more rapid decay of intact viral genomes, decreased genetic complexity and immune escape in reservoirs, which could accelerate reservoir clearance when combined with other interventional strategies.
PubMed: 38947072
DOI: 10.1101/2024.02.16.24302713 -
Genetics Jul 2024APOBEC proteins are cytidine deaminases that restrict the replication of viruses and transposable elements. Several members of the APOBEC3 family, APOBEC3A, APOBEC3B,...
APOBEC proteins are cytidine deaminases that restrict the replication of viruses and transposable elements. Several members of the APOBEC3 family, APOBEC3A, APOBEC3B, and APOBEC3H-I, can access the nucleus and cause what is thought to be indiscriminate deamination of the genome, resulting in mutagenesis and genome instability. Although APOBEC3C is also present in the nucleus, the full scope of its deamination target preferences is unknown. By expressing human APOBEC3C in a yeast model system, I have defined the APOBEC3C mutation signature, as well as the preferred genome features of APOBEC3C targets. The APOBEC3C mutation signature is distinct from those of the known cancer genome mutators APOBEC3A and APOBEC3B. APOBEC3C produces DNA strand-coordinated mutation clusters, and APOBEC3C mutations are enriched near the transcription start sites of active genes. Surprisingly, APOBEC3C lacks the bias for the lagging strand of DNA replication that is seen for APOBEC3A and APOBEC3B. The unique preferences of APOBEC3C constitute a mutation profile that will be useful in defining sites of APOBEC3C mutagenesis in human genomes.
PubMed: 38946641
DOI: 10.1093/genetics/iyae092 -
Human Vaccines & Immunotherapeutics Dec 2024Cervical cancer is the fourth most common cancer, with 99% of cases linked to human papillomavirus (HPV) infection. It reflects global inequity as its burden is highest...
Cervical cancer is the fourth most common cancer, with 99% of cases linked to human papillomavirus (HPV) infection. It reflects global inequity as its burden is highest in low- and middle-income countries. The aim of this study was to determine the HPV vaccination coverage and its determinant factors among young women in the three sub-Saharan African countries. Data from the Demographic and Health Surveys among three sub-Saharan African countries were used for analysis. A total of 4,952 women were included in the study. Stata 14 was used to analyze the data. The determinants of the outcome variable were identified using a multilevel mixed-effects logistic regression model. Factors with p-values < 0.05 at 95% confidence interval were declared statistically significant. About 7.5% young women were vaccinated for HPV vaccine against cervical cancer in the current study. Younger age, use of internet, rich economic class, and individual-level media exposure were found to be favorable conditions, whereas being employed was negatively associated with HPV vaccination. Only few segments of young women in these three countries got HPV vaccination. The authors recommend that increasing internet use, media exposure, and economic level of young women will increase the HPV vaccination rates. Furthermore, creating awareness among employed women will also increase the possibility of HPV vaccination.
Topics: Humans; Female; Papillomavirus Vaccines; Young Adult; Papillomavirus Infections; Vaccination Coverage; Adolescent; Uterine Cervical Neoplasms; Africa South of the Sahara; Adult; Health Surveys; Vaccination; Health Knowledge, Attitudes, Practice; Human Papillomavirus Viruses
PubMed: 38946555
DOI: 10.1080/21645515.2024.2370111 -
Chinese Medical Journal Jun 2024Chronic hepatitis B virus (HBV) infection is a global public health concern. Existing antiviral drugs, including nucleos(t)ide analogs and interferon-α, can suppress...
Chronic hepatitis B virus (HBV) infection is a global public health concern. Existing antiviral drugs, including nucleos(t)ide analogs and interferon-α, can suppress HBV replication and improve the prognosis. However, the persistence of covalently closed circular DNA (cccDNA), the integration of HBV-DNA into the host genome, and compromised immune responses impede the successful treatment of hepatitis B. While achieving a functional cure of HBV remains elusive with the current treatment methods, this is the goal of new therapeutic approaches. Therefore, developing novel antiviral drugs is necessary for achieving a functional or complete cure for chronic hepatitis B. In recent years, substantial progress has been made in drug discovery and development for HBV infection. Direct-acting antiviral agents such as entry inhibitors, capsid assembly modulators, subviral particle release inhibitors, cccDNA silencers, and RNA interference molecules have entered clinical trials. In addition, several immunomodulatory agents, including toll-like receptor agonists, therapeutic vaccines, checkpoint inhibitors, and monoclonal antibodies, are also making their way toward clinical use. In this review, we summarize the recent progress and limitations of chronic hepatitis B treatment and discuss perspectives on approaches to achieving functional cure. Although it will take some time for these new antiviral drugs to be widely used in clinical practice, combination therapy may become a preferable treatment option in the future.
PubMed: 38945693
DOI: 10.1097/CM9.0000000000003178 -
Gene Jun 2024The adeno-associated virus (AAV) is a defective single-stranded DNA virus with the simplest structure reported to date. It constitutes a capsid protein and... (Review)
Review
The adeno-associated virus (AAV) is a defective single-stranded DNA virus with the simplest structure reported to date. It constitutes a capsid protein and single-stranded DNA. With its high transduction efficiency, low immunogenicity, and tissue specificity, it is the most widely used and promising gene therapy vector. The clustered regularly interspaced short palindromic sequence (CRISPR)/CRISPR-associated protein 9 (Cas9) gene editing system is an emerging technology that utilizes cas9 nuclease to specifically recognize and cleave target genes under the guidance of small guide RNA and realizes gene editing through homologous directional repair and non-homologous recombination repair. In recent years, an increasing number of animal experiments and clinical studies have revealed the great potential of AAV as a vector to deliver the CRISPR/cas9 system for treating genetic diseases and viral infections. However, the immunogenicity, toxicity, low transmission efficiency in brain and ear tissues, packaging size limitations of AAV, and immunogenicity and off-target effects of Cas9 protein pose several clinical challenges. This research reviews the role, challenges, and countermeasures of the AAV-CRISPR/cas9 system in gene therapy.
PubMed: 38945310
DOI: 10.1016/j.gene.2024.148733 -
Mymensingh Medical Journal : MMJ Jul 2024Major causes of acute insult in Hepatitis B virus related acute on chronic liver failure in the Asian region are reactivation of Hepatitis B virus and super infection... (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
Major causes of acute insult in Hepatitis B virus related acute on chronic liver failure in the Asian region are reactivation of Hepatitis B virus and super infection with hepatitis A and E virus (ACLF). Anti viral therapy should be started as soon as possible in the ACLF patients at presentation while waiting for confirmation by HBV DNA level. This randomized controlled trial was carried out at the Department of Hepatology, BSMMU, Bangladesh from September 2019 to august 2020 with Hepatitis B virus related ACLF patient. This trial was conducted among twenty seven HBV acute on chronic liver failure patient to compare Child Turcotte pugh (CTP) score, Model for end stage liver disease (MELD) score, Asia Pacific Association for study of Liver (APASL) ACLF Research consortium (AARC) score, survival of the patients and HBV DNA level at 3 months with antiviral therapy between tenofovir alafenamide (25mg) and entecavir (0.5mg) group. CTP score, MELD score and AARC score were significantly (p<0.05) decline from baseline to all subsequent follow-up at 1st (at 7 days), 2nd (at 14 days), 3rd (at 30 days) and 4th (at 90 days) in each group but non significant (p>0.05) difference occurred between two group. All twenty seven patients had detectable HBV DNA level at pre-treatment and all survived patients became undectable at 4th, 90 days follow-up. Total 10 patients (37.07%) were survived at 90 days follow-up, out of them seven patients (70.0%) were in tenofovir alafenamide group and three patients (30.0%) were in entecavir group which was statistically significant (p<0.05) in between two group. Hepatic encephalopathy and hepatorenal syndrome were most common causes of death in both groups. Both drugs tenofovir alafenamide and entecavir significantly improves liver functions but the former one is superior regarding survival.
Topics: Humans; Tenofovir; Guanine; Antiviral Agents; Male; Acute-On-Chronic Liver Failure; Female; Adult; Middle Aged; Treatment Outcome; Alanine; Hepatitis B; Hepatitis B virus
PubMed: 38944709
DOI: No ID Found -
Lancet (London, England) Jun 2024
Topics: Humans; Epstein-Barr Virus Infections; Herpesvirus 4, Human
PubMed: 38944517
DOI: 10.1016/S0140-6736(24)01082-1 -
The Journal of Biological Chemistry Jun 2024Z-nucleic acid structures play vital roles in cellular processes and have implications in innate immunity due to their recognition by Zα domains containing proteins...
Z-nucleic acid structures play vital roles in cellular processes and have implications in innate immunity due to their recognition by Zα domains containing proteins (Z-DNA/Z-RNA binding proteins, ZBPs). Although Zα domains have been identified in six proteins, including viral E3L, ORF112, and I73R, as well as, cellular ADAR1, ZBP1, and PKZ, their prevalence across living organisms remains largely unexplored. In this study, we introduce a computational approach to predict Zα domains, leading to the revelation of previously unidentified Zα domain-containing proteins in eukaryotic organisms, including non-metazoan species. Our findings encompass the discovery of new ZBPs in previously unexplored giant viruses, members of the Nucleocytoviricota phylum. Through experimental validation, we confirm the Zα functionality of select proteins, establishing their capability to induce the B-to-Z conversion. Additionally, we identify Zα-like domains within bacterial proteins. While these domains share certain features with Zα domains, they lack the ability to bind to Z-nucleic acids or facilitate the B-to-Z DNA conversion. Our findings significantly expand the ZBP family across a wide spectrum of organisms and raise intriguing questions about the evolutionary origins of Zα-containing proteins. Moreover, our study offers fresh perspectives on the functional significance of Zα domains in virus sensing and innate immunity and opens avenues for exploring hitherto undiscovered functions of ZBPs.
PubMed: 38944123
DOI: 10.1016/j.jbc.2024.107504 -
International Journal of Biological... Jun 2024The membrane-associated RING-CH 8 protein (MARCH8), a member of the E3 ubiquitin ligase family, has broad-spectrum antiviral activity. However, some viruses hijack...
The membrane-associated RING-CH 8 protein (MARCH8), a member of the E3 ubiquitin ligase family, has broad-spectrum antiviral activity. However, some viruses hijack MARCH8 to promote virus replication, highlighting its dual role in the viral lifecycle. Most studies on MARCH8 have focused on RNA viruses, leaving its role in DNA viruses largely unexplored. Pseudorabies virus (PRV) is a large DNA virus that poses a potential threat to humans. In this study, we found that MARCH8 inhibited PRV replication at the cell-to-cell fusion stage. Interestingly, our findings proved that MARCH8 blocks gB cleavage by recruiting furin but this activity does not inhibit viral infection in vitro. Furthermore, we confirmed that MARCH8 inhibits cell-to-cell fusion independent of its E3 ubiquitin ligase activity but dependent on the interaction with the cell-to-cell fusion complex (gB, gD, gH, and gL). Finally, we discovered that the distribution of the cell-to-cell fusion complex is significantly altered and trapped within the trans-Golgi network. Overall, our results indicate that human MARCH8 acts as a potent antiviral host factor against PRV via trapping the cell-to-cell fusion complex in the trans-Golgi network.
PubMed: 38944094
DOI: 10.1016/j.ijbiomac.2024.133463 -
Molekuliarnaia Biologiia 2024Murine gammaherpesvirus 68 (MHV68) establishes latency mainly in B cells and causes lymphomas reminiscent of human gammaherpesvirus diseases in laboratory mice. To study...
Murine gammaherpesvirus 68 (MHV68) establishes latency mainly in B cells and causes lymphomas reminiscent of human gammaherpesvirus diseases in laboratory mice. To study the molecular mechanism of virus infection and how the viral determinants control cell and eventually cause tumorigenesis, readily available latently infected cell lines are essential. For in vitro MHV68 latency studies, only two cell culture systems have been available. Gammaherpesviruses are known to infect developing B cells and macrophages, therefore we aimed to expand the MHV68 latently infected cell line repertoire. Here, several latently infected immature B cell and macrophage-like cell line clones were generated. Hygromycin-resistant recombinant MHV68 was isolated from a laboratory-made latent cell line, HE2.1, and propagated to develop stable cell lines that carry the viral genome under hygromycin selection. Subclones of these cells lines were analyzed for viral miRNA expression by TaqMan qPCR and assessed for expression of a lytic viral transcript M3. The cell lines maintain the viral genome as an episome shown by the digestion-circularization PCR assay. Latently infected cell lines generated here do not express viral miRNAs higher than the parental cell line. However, these cell lines may provide an alternative tool to study latency mechanisms and miRNA target identification studies.
Topics: Animals; Mice; MicroRNAs; Virus Latency; Genome, Viral; Hygromycin B; Macrophages; Rhadinovirus; RNA, Viral; Cell Line; Gene Expression Regulation, Viral; Precursor Cells, B-Lymphoid; Herpesviridae Infections; Cinnamates
PubMed: 38943586
DOI: No ID Found