Dynamics of peripheral T cell exhaustion and monocyte subpopulations in neurocognitive impairment and brain atrophy in chronic HIV infection.

BACKGROUND: HIV-associated neurocognitive disorders (HAND) is hypothesized to be a result of myeloid cell-induced neuro-inflammation in the central nervous system that may be initiated in the periphery, but the contribution of peripheral T cells in HAND pathogenesis remains poorly understood. METHODS: We assessed markers of T cell activation (HLA-DR + CD38+), immunosenescence (CD57 + CD28-), and immune-exhaustion (TIM-3, PD-1 and TIGIT) as well as monocyte subsets (classical, intermediate, and non-classical) by flow cytometry in peripheral blood derived from individuals with HIV on long-term stable anti-retroviral therapy (ART). Additionally, normalized neuropsychological (NP) composite test z-scores were obtained and regional brain volumes were assessed by magnetic resonance imaging (MRI). Relationships between proportions of immune phenotypes (of T-cells and monocytes), NP z-scores, and brain volumes were analyzed using Pearson correlations and multiple linear regression models. RESULTS: Of N = 51 participants, 84.3% were male, 86.3% had undetectable HIV RNA < 50 copies/ml, median age was 52 [47, 57] years and median CD4 T cell count was 479 [376, 717] cells/uL. Higher CD4 T cells expressing PD-1 + and/or TIM-3 + were associated with lower executive function and working memory and higher CD8 T cells expressing PD-1+ and/or TIM-3+ were associated with reduced brain volumes in multiple regions (putamen, nucleus accumbens, cerebellar cortex, and subcortical gray matter). Furthermore, higher single or dual frequencies of PD-1 + and TIM-3 + expressing CD4 and CD8 T-cells correlated with higher CD16 + monocyte numbers. CONCLUSIONS: This study reinforces evidence that T cells, particularly those with immune exhaustion phenotypes, are associated with neurocognitive impairment and brain atrophy in people living with HIV on ART. Relationships revealed between T-cell immune exhaustion and inflammatory in CD16+ monocytes uncover interrelated cellular processes likely involved in the immunopathogenesis of HAND.

Co-emulsified Alginate-Eudragit Nanoparticles: Potential Carriers for Localized and Time-defined Release of Tenofovir in the Female Genital Tract.

This research aimed to explore the possibilities of Eudragit S100 (ES100) and sodium alginate as carriers for tenofovir disoproxil fumarate (TDF) in the female genital tract. Alginate and alginate-ES100 nanoparticles were prepared using the ionic gelation and emulsion/gelation complexation method, respectively. The nanocarriers were tested using morphological, physicochemical, in vitro drug release, and cytotoxicity analyses. In SEM and TEM images, the presence of spherical and uniformly distributed nanoparticles was revealed. The FTIR spectrum showed that alginate and calcium chloride interacted due to ionic bonds linking divalent calcium ions and the -COO- of alginate groups. Alginate and ES100 interacted via the ester C=O amide stretching. The results obtained from XRD and DSC, on the other hand, revealed a favorable interaction between sodium alginate and ES100 polymers, as evidenced by the crystallization peaks observed. Under experimental design analysis and optimization, overall size distribution profiles ranged from 134.9 to 228.0 nm, while zeta potential results showed stable nanoparticles (-17.8 to -38.4 MV). The optimal formulation exhibited a maximum cumulative in vitro release of 72% (pH 4.2) up to 96 h. The cytotoxicity tests revealed the safety of TDF-loaded nanoparticles on vaginal epithelial cells at concentrations of 0.025 mg/mL, 0.5 mg/mL, and 1 mg/mL for 72 h. These results indicated that alginate-ES100 nanoparticles have the potential to preserve and sustain the release of the TDF drug in the FGT. The future goal is to develop a low-dose non-toxic microbicide that can be administered long term in the vagina to cater to both pregnant and non-pregnant HIV patients.

Cognitive function and impact on driving after SARS-COV-2 infection in a man with long-standing HIV infection: a case report.

A substantial number of individuals who experience COVID-19 infection experience prolonged physical and mental symptoms after resolution of their initial infection, and among them, many individuals experience cognitive difficulties including memory lapses and executive function difficulties, often referred to as "brain fog." The possible impact of COVID-19 infection on cognition in persons with HIV-related cognitive disorders is unknown. In this report, we describe post-COVID-19 cognitive and driving function in a 62-year-old man with HIV infection since the early 1990s.

Turkish Plants, Including Quercetin and Oenothein B, Inhibit the HIV-1 Release and Accelerate Cell Apoptosis.

The introduction of combined anti-retroviral therapy (cART) in 1996, along with a continual breakthrough in anti-human immunodeficiency virus-1 (HIV-1) drugs, has improved the life expectancies of HIV-1-infected individuals. However, the incidence of drug-resistant viruses between individuals undergoing cART and treatment-naïve individuals is a common challenge. Therefore, there is a requirement to explore potential drug targets by considering various stages of the viral life cycle. For instance, the late stage, or viral release stage, remains uninvestigated extensively in antiviral drug discovery. In this study, we prepared a natural plant library and selected candidate plant extracts that inhibited HIV-1 release based on our laboratory-established screening system. The plant extracts from Epilobium hirsutum L. and Chamerion angustifolium (L.) Holub, belonging to the family Onagraceae, decreased HIV-1 release and accelerated the apoptosis in HIV-1-infected T cells but not uninfected T cells. A flavonol glycoside quercetin with oenothein B in Onagraceae reduced HIV-1 release in HIV-1-infected T cells. Moreover, extracts from Chamerion angustifolium (L.) Holub and Senna alexandrina Mill. inhibited the infectivity of progeny viruses. Together, these results suggest that C. angustifolium (L.) Holub contains quercetin with oenothein B that synergistically blocks viral replication and kills infected cells via an apoptotic pathway. Consequently, the plant extracts from the plant library of Turkey might be suitable candidates for developing novel anti-retroviral drugs that target the late phase of the HIV-1 life cycle.

Abortive HIV-1 RNA induces pro-IL-1ß maturation via protein kinase PKR and inflammasome activation in humans.

The proinflammatory cytokine IL-1ß mediates high levels of immune activation observed during acute and chronic human immunodeficiency virus 1 (HIV-1) infection. Little is known about the mechanisms that drive IL-1ß activation during HIV-1 infection. Here, we have identified a crucial role for abortive HIV-1 RNAs in inducing IL-1ß in humans. Abortive HIV-1 RNAs were sensed by protein kinase RNA-activated (PKR), which triggered activation of the canonical NLRP3 inflammasome and caspase-1, leading to pro-IL-1ß processing and secretion. PKR activated the inflammasome via ROS generation and MAP kinases ERK1/2, JNK, and p38. Inhibition of PKR during HIV-1 infection blocked IL-1ß production. As abortive HIV-1 RNAs are produced during productive infection and latency, our data strongly suggest that targeting PKR signaling might attenuate immune activation during acute and chronic HIV-1 infection.

Evaluation of cytokine levels in response to mitogen among HIV-1-infected blood cells and their relationships to the number of T cells.

BACKGROUND: Human immunodeficiency virus-1 (HIV-1) infection causes loss and anergy of CD4+ and CD8+ T cells, leading to opportunistic infections, including tuberculosis (TB). QuantiFERON®-TB (QFT) is used as a diagnostic tool to detect TB, but it exhibits limited accuracy among subjects with low CD4+ T cell numbers, including HIV-1-infected individuals. The present study aimed to determine the effect of HIV-1 infection and patients' blood T cell numbers on cytokine production in response to mitogen (Mit) stimulation. METHODS: The number of CD4+ and CD8+ T cells in HIV-1-infected individuals was quantified. Levels of various cytokines in Mit-stimulated and un-stimulated (Nil) supernatants of QFT gold "in tube" were assessed using a MAGPIX System. The correlation between cytokine levels and CD4+/CD8+ T cell counts in response to Mit was analyzed. The cytokine levels were compared between HIV-1-infected and healthy subjects. RESULTS: HIV-1-infected individuals (110) and control subjects (27) were enrolled. Interferon (IFN)-γ, interleukin-1 receptor antagonist (IL-1RA), IL-6, IL-8, and regulated on activation, normal T cell expressed and secreted (RANTES) values in Mit-Nil tubes showed a significant correlation with CD4+ T cell counts, while IFN-γ, IL-6, and IFN-γ-induced protein 10 (IP-10) values in Mit-Nil tubes had significant correlation with CD8+ T cell counts. IL-1RA, IL-8, IP-10, platelet-derived growth factor (PDGF)-BB, and RANTES levels in Nil tubes were significantly higher in the HIV-1-infected group. IFN-γ, IL-2, IL-5, IL-6, IP-10, and macrophage inflammatory protein-1ß values in Mit-Nil tubes were significantly higher, and PDGF-BB and RANTES levels were significantly lower in the HIV-1-infected group. CONCLUSION: The functions of HIV-1-infected T cells and uninfected T cells, such as spontaneous and responsive cytokine production in response to Mit, were different. Our findings may be useful for developing new clinical tools for patients with low T cell counts. Additionally, the study provides new insights into the pathogenesis of HIV-1 infection.

Single-molecule imaging of HIV-1 envelope glycoprotein dynamics and Gag lattice association exposes determinants responsible for virus incorporation.

The HIV-1 envelope glycoprotein (Env) is sparsely incorporated onto assembling virus particles on the host cell plasma membrane in order for the virus to balance infectivity and evade the immune response. Env becomes trapped in a nascent particle on encounter with the polymeric viral protein Gag, which forms a dense protein lattice on the inner leaflet of the plasma membrane. While Env incorporation efficiency is readily measured biochemically from released particles, very little is known about the spatiotemporal dynamics of Env trapping events. Herein, we demonstrate, via high-resolution single-molecule tracking, that retention of Env trimers within single virus assembly sites requires the Env cytoplasmic tail (CT) and the L12 residue in the matrix (MA) domain of Gag but does not require curvature of the viral lattice. We further demonstrate that Env trimers are confined to subviral regions of a budding Gag lattice, supporting a model where direct interactions and/or steric corralling between the Env-CT and a lattice of MA trimers promote Env trapping and infectious HIV-1 assembly.

Synthesis of carbon-14 and stable isotope labeled Censavudine.

Censavudine is a nucleoside reverse transcriptase inhibitor (NRTI) explored clinically by Bristol Myers Squibb for the treatment of human immunodeficiency virus-1 (HIV-1). As part of the development process, a carbon-14 labeled analog was synthesized for use in a human absorption, distribution, metabolism, and excretion (ADME) study. A stable isotope labeled analog was also synthesized for use as a mass spectrum internal standard in bioanalytical assays to accurately quantify the concentration of the drug in biological samples. Carbon-14 labeled Censavudine was synthesized in 10 steps in a 9% overall yield from carbon-14 labeled trimethylsilylacetylene. A total of 4.44 mCi of material was prepared with a specific activity of 0.25 µCi/mg. The radiochemical and UV purities were 99% and it met all of the specifications for use in a human clinical study. Deuterium labeled Censavudine was synthesized in two steps in a 68% overall yield from [D4 ]-thymine. A total of 237 mg were prepared with a UV purity of 99%.

Prevalence of HIV-1 infection among foreign applicant to residency in Shanghai, China, 2005-2016.

Shanghai is one of the largest cities in China and has the highest proportion of inbound travelers in the world. The HIV (human immunodeficiency virus) infection status of this population can reflect the global HIV epidemic trend to a certain extent. Therefore, we conducted a retrospective epidemic survey to clarify the prevalence and characteristics of HIV-1 infection among inbound travelers applying for Shanghai residency. The retrospective cohort analysis included a total of 50,830 inbound tourists/travelers who applied for Shanghai residency from 2005 to 2016. HIV-1 infection rates were determined based on HIV-1 antibody testing. Among all the recruited inbound travelers, 245 were HIV-1 positive, with an infection rate of 0.48%. The detection rate of HIV in males was significantly higher than in females (χ2 = 62.584, P < 0.0001). Those aged 18-30 years, 31-40 years, and >40 years accounted for 34.3%, 39.6%, and 26.1% of the infected population, respectively. Although the annual detection rates were different, the trend analysis results showed no increase in HIV-1 prevalence rates among the sampling years (Cochran-Armitage Z = 2.543, P = 0.111). Proportions of individuals infected through homosexual transmission increased over the study period (Cochran-Armitage Z = 5.41, P < 0.001), while the proportion infected through heterosexual declined over time (Cochran-Armitage Z = 3.38, P = 0.001). The rate and characteristics of HIV-1 infection among foreign applicants for residency in Shanghai were identified in the study. The results provide the necessary epidemiological data for monitoring the HIV-1 epidemic among international entry travelers and contribute to establishing relevant policies and regulations for HIV control and prevention.

Behavioral Evidence for a Tau and HIV-gp120 Interaction.

Despite successful virologic control with combination antiretroviral therapy (cART), about half of people living with the human immunodeficiency virus-1 (HIV) develop an HIV-associated neurocognitive disorder (HAND). It is estimated that 50% of individuals who are HIV-positive in the United States are aged 50 years or older. Therefore, a new challenge looms as individuals living with HIV increase in age. There is concern that Alzheimer's disease (AD) may become prevalent with an earlier onset of cognitive decline in people living with HIV (PLWH). Clinical data studies reported the presence of AD biomarkers in PLWH. However, the functional significance of the interaction between HIV or HIV viral proteins and AD biomarkers is still not well studied. The main goal of the present study is to address this knowledge gap by determining if the HIV envelope glycoprotein 120 (HIV-gp120) can affect the cognitive functions in the Tau mouse AD model. Male Tau and age-matched, wild-type (WT) control mice were treated intracerebroventricularly (ICV) with HIV-gp120. The animals were evaluated for cognitive function using a Y-maze. We found that HIV-gp120 altered cognitive function in Tau mice. Notably, HIV-gp120 was able to promote a cognitive decline in transgenic Tau (P301L) mice compared to the control (HIV-gp120 and WT). We provide the first in vivo evidence of a cognitive interaction between an HIV viral protein and Tau mice.

OLGenie: Estimating Natural Selection to Predict Functional Overlapping Genes.

Purifying (negative) natural selection is a hallmark of functional biological sequences, and can be detected in protein-coding genes using the ratio of nonsynonymous to synonymous substitutions per site (dN/dS). However, when two genes overlap the same nucleotide sites in different frames, synonymous changes in one gene may be nonsynonymous in the other, perturbing dN/dS. Thus, scalable methods are needed to estimate functional constraint specifically for overlapping genes (OLGs). We propose OLGenie, which implements a modification of the Wei-Zhang method. Assessment with simulations and controls from viral genomes (58 OLGs and 176 non-OLGs) demonstrates low false-positive rates and good discriminatory ability in differentiating true OLGs from non-OLGs. We also apply OLGenie to the unresolved case of HIV-1's putative antisense protein gene, showing significant purifying selection. OLGenie can be used to study known OLGs and to predict new OLGs in genome annotation. Software and example data are freely available at https://github.com/chasewnelson/OLGenie (last accessed April 10, 2020).

Frequency of Cytomegalovirus Viral Load in Iranian Human Immunodeficiency Virus-1-Infected Patients with CD4+ Counts <100 Cells/mm3.

OBJECTIVES: The aim of present work was to assess cytomegalovirus (CMV) viremia in Iranian human immunodeficiency virus (HIV)-1-infected patients with a CD4+ count <100 cells/mm3 and to explore whether CMV DNA loads correlate with CD4+ cell counts or associated retinitis. METHODS: This study was conducted at the AIDS research center in Iran on HIV-1-infected patients with CD4+ count <100 cells/mm3, antiretroviral therapy-naive, aged ≥18 years with no previous history of CMV end-organ disease (CMV-EOD). RESULTS: Thirty-nine of 82 patients (47.56%) had detectable CMV viral load ranging from 66 to 485,500 IU/mL. CMV viral load in patients with retinitis ranges from 352 to 2,720 IU/mL, and it was undetectable in 2 patients. No significant associations between CMV viremia and CD4+ cell count was found (p value = 0.31), whereas significant association of CMV viremia in HIV-infected patients with retinitis was found (p < 0.02). CONCLUSIONS: We estimated the frequency of CMV viral load infection in Iranian HIV-1-infected patients with a CD4+ cell count <100 mm3/mL in the largest national referral center for HIV-1 infection in Iran. Further research is required on the relevance of CMV viral load in diagnostic and prognostic value of CMV-EOD.

HIV drug resistance and HIV transmission risk factors among newly diagnosed individuals in Southwest China.

BACKGROUND: The widespread use of antiretroviral therapy (ART) has resulted in the development of transmitted drug resistance (TDR), which reduces ART efficacy. We explored TDR prevalence and its associated risk factors in newly diagnosed individuals in Guangxi. METHODS: We enrolled 1324 participants who were newly diagnosed with HIV-1 and had not received ART at voluntary counselling and testing centres (VCT) in Guangxi, China, who had not received ART. Phylogenetic relationship, transmission cluster, and genotypic drug resistance analyses were performed using HIV-1 pol sequences. We analysed the association of demographic and virological factors with TDR. RESULTS: In total, 1151 sequences were sequenced successfully, of which 83 (7.21%) showed evidence of TDR. Multivariate logistic regression analysis revealed that there was significant difference between the prevalence of TDR and unmarried status (adjusted odds ratio (aOR) = 2.41, 95% CI: 1.23-4.71), and CRF08_BC subtype (aOR = 2.03, 95% CI: 1.13-3.64). Most cases of TDR were related to resistance to non-nucleoside reverse transcriptase inhibitors (4.87%) and V179E was the most common mutation detected. We identified a total of 119 HIV transmission clusters (n = 585, 50.8%), of which 18 (15.1%) clusters showed evidence of TDR (36, 41.86%). Three clusters were identified that included drug-resistant individuals having a transmission relationship with each other. The following parameters were associated with TDR transmission risk: Unmarried status, educational level of junior high school or below, and CRF08_BC subtype may be a risk of the transmission of TDR. CONCLUSIONS: Our findings indicated that moderate TDR prevalence and highlighted the importance of continuous TDR monitoring and designing of strategies for TDR mitigation.

Evaluation of CCR5-Δ32 mutation among individuals with high risk behaviors, neonates born to HIV-1 infected mothers, HIV-1 infected individuals, and healthy people in an Iranian population.

One of the important genetic factors related to resistance to HIV-1 infection is the presence of the C-C chemokine receptor type 5 delta 32 (CCR5-Δ32) homozygous genotype (Δ32/Δ32). The aim of this study was to evaluate the CCR5-Δ32 mutation among individuals with high-risk behaviors, neonates born to HIV-1-infected mothers in the prevention of mother-to-child transmission (PMTCT) project, HIV-1-infected individuals, and healthy people. The frequency of the CCR5-Δ32 genotype was assessed in a cross-sectional survey carried out from March 2014 to March 2019 among four different groups of the Iranian population. Genomic DNA was extracted from peripheral blood mononuclear cells of 140 Iranian healthy people, 84 neonates born to HIV-1-infected mothers in the PMTCT project, 71 people with high-risk behaviors, and 76 HIV-1-infected individuals. The polymerase chain reaction method was used for the amplification of the CCR5 gene. The CCR5-Δ32 heterozygous deletion was detected in five (6.6%) HIV-1-infected individuals, four (4.7%) neonates born to HIV-1 positive mothers, two (1.4%) healthy people, and also three (4.2%) people with high-risk behaviors whereas the CCR5-Δ32 homozygous deletion was absent in all the groups (Fisher's exact test, P = .0242). The allele of CCR5-Δ32 homozygous was not detected in the four study groups, and no significant difference was seen in the frequency of the CCR5Δ32 heterozygous allele between HIV seropositive and seronegative individuals. Therefore, it seems that this allele alone cannot explain the natural resistance to HIV-1 infection and probably several mechanisms are responsible for these processes and it should be further investigated.

Antiviral potential of garlic (Allium sativum) and its organosulfur compounds: A systematic update of pre-clinical and clinical data.

BACKGROUND: Garlic (Allium sativum L.) is a common herb consumed worldwide as functional food and traditional remedy for the prevention of infectious diseases since ancient time. Garlic and its active organosulfur compounds (OSCs) have been reported to alleviate a number of viral infections in pre-clinical and clinical investigations. However, so far no systematic review on its antiviral effects and the underlying molecular mechanisms exists. SCOPE AND APPROACH: The aim of this review is to systematically summarize pre-clinical and clinical investigations on antiviral effects of garlic and its OSCs as well as to further analyse recent findings on the mechanisms that underpin these antiviral actions. PubMed, Cochrane library, Google Scholar and Science Direct databases were searched and articles up to June 2020 were included in this review. KEY FINDINGS AND CONCLUSIONS: Pre-clinical data demonstrated that garlic and its OSCs have potential antiviral activity against different human, animal and plant pathogenic viruses through blocking viral entry into host cells, inhibiting viral RNA polymerase, reverse transcriptase, DNA synthesis and immediate-early gene 1(IEG1) transcription, as well as through downregulating the extracellular-signal-regulated kinase (ERK)/mitogen activated protein kinase (MAPK) signaling pathway. The alleviation of viral infection was also shown to link with immunomodulatory effects of garlic and its OSCs. Clinical studies further demonstrated a prophylactic effect of garlic in the prevention of widespread viral infections in humans through enhancing the immune response. This review highlights that garlic possesses significant antiviral activity and can be used prophylactically in the prevention of viral infections.

B1 protein: a novel cell penetrating protein for in vitro and in vivo delivery of HIV-1 multi-epitope DNA constructs.

OBJECTIVES: Enhancement of the potential ability of biomacromolecules to cross cell membranes is a critical step for development of effective therapeutic vaccine especially DNA vaccine against human immunodeficiency virus-1 (HIV-1) infection. The supercharged proteins were known as powerful weapons for delivery of different types of cargoes such as DNA and protein. Hence, we applied B1 protein with + 43 net charges obtained from a single frameshift in the gene encoding enhanced green fluorescent protein (eGFP) for delivery of two multi-epitope DNA constructs (nef-vpu-gp160-p24 and nef-vif-gp160-p24) in vitro and in vivo for the first time. For this purpose, B1 protein was generated in bacterial expression system under native conditions, and used to interact with both DNA constructs. RESULTS: Our data indicated that B1 protein (~ 27 kDa) was able to form a stable nanoparticle (~ 80-110 nm) with both DNA constructs at nitrogen: phosphate (N: P) ratio of 1:1. Moreover, the transfection efficiency of B1 protein for DNA delivery into HEK-293T cell line indicated that the cellular uptake of nef-vif-gp160-p24 DNA/ B1 and nef-vpu-gp160-p24 DNA/ B1 nanoparticles was about 32-35% with lower intensity as compared to TurboFect commercial reagent. On the other hand, immunization of BALB/c mice with different modalities demonstrated that B1 protein could enhance the levels of antibody, IFN-gamma and Granzyme B eliciting potent and strong Th1-directed cellular immunity. CONCLUSION: Generally, our findings showed the potency of B1 protein as a promising gene delivery system to improve an effective therapeutic vaccine against HIV-1 infection.

Potent Antibacterial Activity of Synthetic Peptides Designed from Salusin-ß and HIV-1 Tat(49-57).

Salusin-ß is an endogenous bioactive peptide that was identified in a human full-length enriched cDNA library using bioinformatics analyses. In our previous study, we found that synthetic salusin-ß exhibits antibacterial activity against only Gram-positive microorganisms such as Staphylococcus aureus NBRC 12732. Salusin-ß has an ability to depolarize the cytoplasmic membrane of this bacterium, and this phenomenon may be linked to the antibacterial activity of this peptide. A cell-penetrating peptide (CPP), human immunodeficiency virus (HIV)-1 transactivator of transcription (Tat) (49-57) is a short cationic peptide that can traverse cell membranes. In this report, synthetic peptide conjugates of salusin-ß and HIV-1 Tat(49-57) showed potent antibacterial activities against both Gram-positive Staphylococcus aureus NBRC 12732 and Gram-negative Escherichia coli NBRC 12734. The synthetic peptides also depolarized the cytoplasmic membrane of Escherichia coli NBRC 12734 as well as Staphylococcus aureus NBRC 12732. These results suggested that HIV-1 Tat(49-57) is a protein transduction domain or CPP that changes the interaction mode between salusin-ß and the cell membrane of Escherichia coli NBRC 12734. By binding to HIV-1 Tat(49-57), salusin-ß showed a broad antibacterial spectrum regardless of whether the target was a Gram-positive or Gram-negative bacterium.

Genetic diversity of human immunodeficiency virus-1 in Nigeria: 2002-2017 - systematic review and meta-analysis.

Nigeria was ranked second highest country with human immunodeficiency virus (HIV) burden worldwide. HIV-1 subtypes and circulating recombinant forms genetic variability affect the protease and reverse transcriptase genes which code for viral enzymes and are the main targets for antiretroviral drugs. Therefore, this study was aimed at reviewing and pooling such HIV-1 subtypes in Nigeria to represent the collective prevalence of each subtype. Studies of HIV-1 subtypes in Nigeria published from 2002 to 2017 were retrieved and synthesised from different sources electronically. Sixteen studies were included for random effect meta-analysis for various subtypes in each study. The pooled prevalence was charted in forest plot and effect estimates from individual studies against some measure of study size or precision were presented in funnel plots. The pooled prevalence of Subtype G, CRF02_AG, CRF06_cpx, Subtype A and Subtype C were 38.27% (95% Confidence Interval [CI]: 21.27%- 55.98%), 37.81% (95% CI: 20.37%- 55.25%), 6.6% (95% CI: 7.10%-7.10%), 14.05% (95% CI: 9.06% - 19.04%) and 2.80% (95% CI: 2.70%- 8.30%) respectively. This study suggests HIV-1 subtypes G, CRF02_AG and A are the most prevalent in Nigeria.

HIV-1 Tat protein induces aberrant activation of AICDA in human B-lymphocytes from peripheral blood.

Individuals infected with human immunodeficiency virus (HIV) are at increased risk for Burkitt lymphoma, a B-cell malignancy which occurs after a chromosomal translocation rearranging the MYC oncogene with an immunoglobulin gene locus, usually the IGH heavy chain gene locus. We have previously reported that the HIV protein Tat which circulates in all HIV-positive individuals whatever their immune status caused an increased rate of colocalization between IGH and MYC in B-cells nuclei. We here present in vitro evidence that Tat activates the expression of the AICDA gene that encodes the activation-induced cytidine deaminase whose physiological function is to create double-strand breaks for immunoglobulin gene maturation. In the presence of Tat, DNA damage was observed concomitantly in both MYC and IGH, followed by DNA repair by nonhomologous end joining. AICDA was further found overexpressed in vivo in peripheral blood B-cells from HIV-infected individuals. Thus, the capacity of Tat to spontaneously penetrate B-cells could be sufficient to favor the occurrence of MYC-IGH oncogenic rearrangements during erroneous repair, a plausible cause for the increased incidence of Burkitt lymphoma in the HIV-infected population.

USP18 (UBP43) Abrogates p21-Mediated Inhibition of HIV-1.

The host intrinsic innate immune system drives antiviral defenses and viral restriction, which includes the production of soluble factors, such as type I and III interferon (IFN), and activation of restriction factors, including SAMHD1, a deoxynucleoside triphosphohydrolase. Interferon-stimulated gene 15 (ISG15)-specific ubiquitin-like protease 43 (USP18) abrogates IFN signaling pathways. The cyclin-dependent kinase inhibitor p21 (CIP1/WAF1), which is involved in the differentiation and maturation of monocytes, inhibits human immunodeficiency virus type 1 (HIV-1) in macrophages and dendritic cells. p21 inhibition of HIV-1 replication is thought to occur at the reverse transcription step, likely by suppressing cellular deoxynucleoside triphosphate (dNTP) biosynthesis and increasing the amount of antivirally active form of SAMHD1. SAMHD1 strongly inhibits HIV-1 replication in myeloid and resting CD4+ T cells. Here, we studied how USP18 influences HIV-1 replication in human myeloid THP-1 cells. We found that USP18 has the novel ability to inhibit the antiviral function of p21 in differentiated THP-1 cells. USP18 enhanced reverse transcription of HIV-1 by downregulating p21 expression and upregulating intracellular dNTP levels. p21 downregulation by USP18 was associated with the active form of SAMHD1, phosphorylated at T592. USP18 formed a complex with the E3 ubiquitin ligase recognition factor SKP2 (S-phase kinase associated protein 2) and SAMHD1. CRISPR-Cas9 knockout of USP18 increased p21 protein expression and blocked HIV-1 replication. Overall, we propose USP18 as a regulator of p21 antiviral function in differentiated myeloid THP-1 cells.IMPORTANCE Macrophages and dendritic cells are usually the first point of contact with pathogens, including lentiviruses. Host restriction factors, including SAMHD1, mediate the innate immune response against these viruses. However, HIV-1 has evolved to circumvent the innate immune response and establishes disseminated infection. The cyclin-dependent kinase inhibitor p21, which is involved in differentiation and maturation of monocytes, blocks HIV-1 replication at the reverse transcription step. p21 is thought to suppress key enzymes involved in dNTP biosynthesis and activates SAMHD1 antiviral function. We report here that the human USP18 protein is a novel factor potentially contributing to HIV replication by blocking the antiviral function of p21 in differentiated human myeloid cells. USP18 downregulates p21 protein expression, which correlates with upregulated intracellular dNTP levels and the antiviral inactive form of SAMHD1. Depletion of USP18 stabilizes p21 protein expression, which correlates with dephosphorylated SAMHD1 and a block to HIV-1 replication.