Publications by authors named "Hesham Nasser"

Improved antiretroviral therapy (ART) has significantly increased the life expectancy of people living with HIV (PLWH). At the same time, other complications like metabolic syndrome (MetS) are coming up as new challenges to handle. This review aims to explore the emerging evidence of gut microbiome and virome alterations in human immunodeficiency virus-1 (HIV-1) infection and associated metabolic disorders, such as type-2 diabetes (T2DM) and cardiovascular disease (CVD), with a focus on their interplay, contribution to immune dysfunction, and potential as therapeutic targets.

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The global circulation of SARS-CoV-2 in human populations has driven the emergence of Omicron subvariants, which have become highly diversified through recombination. In late 2024, SARS-CoV-2 Omicron XEC variant emerged from the recombination of two JN.1 progeny, KS.

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The apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3 (APOBEC3/A3) family of cytosine deaminases serves as a key innate immune barrier against invading retroviruses and endogenous retroelements. The A3 family's restriction activity against these parasites primarily arises from their ability to catalyze cytosine-to-uracil conversions, resulting in genome editing and the accumulation of lethal mutations in viral genomes. Additionally, non-editing mechanisms, including deaminase-independent pathways, such as blocking viral reverse transcription, have been proposed as antiviral strategies employed by A3 family proteins.

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  • HIV-1-infected individuals on antiretroviral therapy still face higher risks of non-AIDS-related health issues due to ongoing chronic inflammation, marked by specific changes in monocytes like increased CD16 subsets and elevated soluble markers sCD163 and sCD14.
  • The study reveals that IL-10, an anti-inflammatory cytokine, can activate monocytes by increasing CD16 and other soluble markers through multiple signaling pathways, including Stat3 and AMPK.
  • Additionally, the HIV-1 protein Nef promotes the production of IL-10 in macrophages, suggesting that IL-10 contributes to the persistent activated state of monocytes in individuals who have achieved viral suppression.
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  • A new variant of SARS-CoV-2, called EG.5.1, is spreading rapidly and has been studied using various scientific methods to understand its features.
  • Key mutations in EG.5.1, specifically S:F456L and ORF9b:I5T, enhance its viral fitness compared to other variants like XBB.1.5.
  • Structural differences were found in the spike proteins of EG.5.1 versus XBB.1.5, and the research helps us understand the evolution of emerging viruses that can affect human health.
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  • Researchers isolated a coronavirus called BANAL-20-236 (B236) from Malayan horseshoe bats and found it lacks a key site in its spike protein that is present in SARS-CoV-2.
  • * They compared B236's characteristics using human-derived cells and hamster infection experiments, discovering it's less pathogenic and grows slower in respiratory cells compared to SARS-CoV-2, but grows better in intestinal cells.
  • * The study suggests that SC2r-CoVs like B236 may primarily replicate in the intestines rather than the respiratory system, supporting prior findings about its behavior in other models.
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  • The emergence of a new Variant of Interest, XBB.1.5, is linked to mutations from the pre-existing variant XBB.1, specifically an S486P spike mutation and a nonsense mutation in ORF8.
  • Phylogenetic analysis indicates that XBB.1.5 maintains similar immune escape abilities compared to XBB.1, and structural studies reveal that the spike proteins of both variants are largely similar.
  • Research involving hamsters shows that the ORF8 nonsense mutation in XBB.1.5 reduces MHC suppression and results in lower virulence in this variant compared to XBB.1.
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  • In late 2023, the SARS-CoV-2 BA.2.86 variant emerged alongside the dominant XBB descendants like EG.5.1, distinguishing itself with over 30 mutations in its spike protein.
  • Modeling showed BA.2.86 has a higher reproduction number compared to EG.5.1, suggesting it spreads more easily.
  • Despite its increased spread, BA.2.86 demonstrated lower pathogenicity and replication capacity in hamsters, indicating it may be less severe, while remaining sensitive to four existing antiviral treatments.
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  • Most research on SARS-CoV-2 variants has concentrated on mutations in spike proteins that influence how the virus infects and spreads.
  • This study highlights that there are also significant mutations outside of the spike protein that can affect the virus's behavior.
  • Specifically, the study found that certain mutations in the Omicron BA.2 variant, including one in the spike protein and another further down the gene, play crucial roles in defining its characteristics.
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  • - HIV-1 faces resistance from innate antiviral mechanisms in CD4 T lymphocytes and macrophages, particularly from the APOBEC3 (A3) family of proteins, which restrict viral replication.
  • - The virus's virion infectivity factor (Vif) helps it overcome this resistance by degrading A3 proteins, and while it also targets other proteins, its main role appears to focus on A3 proteins.
  • - Experiments using CRISPR to disrupt specific genes in THP-1 cells show that removing A3 proteins completely restores the infectivity of Vif-deficient HIV-1, highlighting that A3 proteins are the primary target for Vif's function in viral production.
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  • In late 2022, the SARS-CoV-2 Omicron subvariant XBB emerged from the recombination of two existing BA.2 lineages, BJ.1 and BM.1.1.1, during the summer of 2022.
  • XBB.1 shows strong resistance to vaccines designed for BA.2/5 and has increased fusogenicity, meaning it can fuse with human cells more efficiently due to changes in its spike protein.
  • Research indicates that while XBB.1 is pathogenic, its disease-causing potential in male hamsters is similar to or lower than that of the BA.2.75 variant, marking a notable adaptation in virus evolution through recombination.
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  • In late 2022, several Omicron subvariants emerged globally, characterized by specific amino acid changes in their spike proteins, indicating convergent evolution.
  • The study highlights a problematic lineage, BQ.1.1, which shows higher viral fitness due to five critical amino acid substitutions and better evasion of immune responses compared to the BA.5 subvariant.
  • In tests on hamsters, BQ.1.1 demonstrated lower pathogenicity than BA.5, revealing insights into the evolutionary patterns of Omicron subvariants up to 2022.
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Unlabelled: HIV-1 must overcome multiple innate antiviral mechanisms to replicate in CD4 T lymphocytes and macrophages. Previous studies have demonstrated that the APOBEC3 (A3) family of proteins (at least A3D, A3F, A3G, and stable A3H haplotypes) contribute to HIV-1 restriction in CD4 T lymphocytes. Virus-encoded virion infectivity factor (Vif) counteracts this antiviral activity by degrading A3 enzymes allowing HIV-1 replication in infected cells.

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Recent studies have revealed the unique virological characteristics of Omicron, particularly those of its spike protein, such as less cleavage efficacy in cells, reduced ACE2 binding affinity, and poor fusogenicity. However, it remains unclear which mutation(s) determine these three virological characteristics of Omicron spike. Here, we show that these characteristics of the Omicron spike protein are determined by its receptor-binding domain.

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  • - The SARS-CoV-2 spike protein plays a crucial role in allowing the virus to enter target cells by facilitating membrane fusion.
  • - A new assay using a dual functional split reporter protein has been developed to quantitatively study the fusion process in living cells, enabling real-time monitoring.
  • - This method can be applied to different cell types and may help predict how harmful new variants of the virus could be, with further details available in the referenced studies.
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  • The SARS-CoV-2 Omicron BA.2.75 variant, emerging in May 2022, is a distinct descendant of BA.2 and shows a greater reproductive number than the dominant BA.5 variant.
  • BA.2.75 demonstrates different responses to vaccines and antibodies, retaining antiviral drug effectiveness but showing variable antibody sensitivity due to unique genetic changes.
  • This variant has enhanced ability to bind to human receptors, increased growth efficiency in lung cells, and heightened pathogenicity in hamsters, indicating a potentially greater risk to global health compared to BA.5.
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  • The emergence of various subvariants of the SARS-CoV-2 Omicron BA.2, such as BA.2.9.1, BA.2.11, BA.2.12.1, BA.4, and BA.5, shows that they have higher effective reproduction numbers compared to the original BA.2 strain.
  • Neutralization experiments indicate that immunity from previous BA.1/2 infections is less effective against the newer BA.4/5 subvariants, which also replicate more efficiently and exhibit greater cell fusion than BA.2.
  • Research using hamsters and structural analysis of the BA.4/5 spike protein suggests that these subvariants are more pathogenic and pose a greater risk to global health
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  • The cytokine IL-32 is found at high levels in HIV-1-infected individuals, but its role is complex as it can both inhibit and stimulate HIV-1 production in different types of immune cells.
  • IL-32 inhibits HIV-1 in monocyte-derived macrophages (MDMs) through the activation of SAMHD1, but this effect is lost when SAMHD1 is depleted, distinguishing its action from that in CD4 T cells.
  • Additionally, IL-32 promotes immunosuppressive molecules and enhances MDM motility, suggesting that its overall impact may favor the progression of HIV-1 infection despite some inhibitory effects.
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  • * COVID vaccines currently in use are ineffective against BA.2, similar to BA.1, and there are significant differences in the virus's antigenicity between the two lineages.
  • * Laboratory studies indicate that BA.2 replicates more effectively in human nasal cells and is more pathogenic than BA.1, suggesting a greater global health risk.
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The emergence of the Omicron variant of SARS-CoV-2 is an urgent global health concern. In this study, our statistical modelling suggests that Omicron has spread more rapidly than the Delta variant in several countries including South Africa. Cell culture experiments showed Omicron to be less fusogenic than Delta and than an ancestral strain of SARS-CoV-2.

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Exposure of cultured mammalian cells to paraformaldehyde (PFA) is an effective approach to induce membrane blebs, which is followed by their detachment from the cellular cortex to yield giant membrane vesicles in extracellular spaces. Although PFA-induced giant vesicles have attracted significant interest in the field of cell membrane dynamics, their biochemical components and cytocompatibility remain largely unknown. In this report, we exposed human cervical cancer HeLa cells to PFA under metal-free buffer conditions to produce giant vesicles.

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  • - The COVID-19 pandemic has led to the emergence of multiple mutations in the SARS-CoV-2 virus, with four variants of concern currently identified as potential threats.
  • - The B.1.617.2/Delta variant, linked to the COVID-19 surge in India during spring 2021, displays notably aggressive traits in infected hamsters.
  • - A specific mutation, P681R, in the spike protein of the B.1.617.2/Delta variant enhances its ability to infect and cause disease, indicating it plays a key role in the virus's increased pathogenicity.
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  • Southern tick-associated rash illness (STARI) is a new tick-borne disease that causes a rash similar to Lyme disease but is distinct in its characteristics.
  • It's believed to be caused by a spirochete and is spread through tick bites, but there's no official test or treatment available yet.
  • The text discusses a unique case of STARI in a 63-year-old woman and highlights how STARI differs from Lyme disease.
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The introduction of combination antiretroviral therapy (cART) has managed to control the replication of human immunodeficiency virus type 1 (HIV-1) in infected patients. However, a complete HIV-1 cure, including a functional cure for or eradication of HIV-1, has yet to be achieved because of the persistence of latent HIV-1 reservoirs in adherent patients. The primary source of these viral reservoirs is integrated proviral DNA in CD4 T cells and other non-T cells.

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Hypokalemic periodic paralysis (HPP) is one of the group muscle disorders that can cause sudden onset paresis or paralysis. It is a quite rare, yet, potentially life-threatening condition that, if appropriately and promptly diagnosed and treated, can be completely reversed. Other forms of periodic paralysis include thyrotoxic periodic paralysis, hyperkalemic periodic paralysis, and Anderson syndrome.

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