The CRISPR-Cas9 induced CCR5 Δ32 mutation as a potent gene therapy methodology for resistance to HIV-1 variant: a review.

Human Immunodeficiency Virus (HIV) has continuously been the greatest epidemic for humanity over a period spanning almost five decades. With no specific cure or treatment available to date despite extensive research, the C-C Chemokine Receptor 5, Delta 32 (CCR5 Δ32) allele genetic point mutation plays an imperative role in the prevention of acquired immunodeficiency syndrome (AIDS). This comprehensive study aims to review the induction of the homozygous recessive deletion genotype using the Clustered Regularly Interspaced Short Palindromic Repeats, Cas 9 Enzyme (CRISPR-Cas9), and hematopoietic stem cell transplantation under positive selection pressure for active immunity in seropositive patients' populations as the phenotype. A methodology is proposed to trigger a significant increase in the expression of Delta 32 beneficial mutant alleles within controlled modern healthcare facilities utilizing totipotent stem cells through somatic gene therapy. It acts upon two dysfunctional CCR5 genes, translating mutant G protein-coupled co-receptors, whose primary function is similar to that of C-X-C Motif Chemokine receptor 4 (CXCR4), by blocking the entry of viral RNA into the CD4+ T helper lymphocytes, halting infection and seizing viral life cycle. This modification is endemic in Northern Europe, where it naturally pertains to the Caucasian descent population samples in the form of polymorphism, p (X=0.01), where X is the probability of frequency of complete immunity against HIV-1 in population samples. The epigenetics of the single nucleotide polymorphism (SNP) are analyzed as they play a significant role in immunity distribution. Furthermore, a comparative analysis within the ethical boundaries of CRISPR-Cas9 is conducted to discuss the practical aspects and challenges of the presented methodologies and treatment alternatives. Additionally, the study assembles all available data and summarizes preexisting research while providing a promising solution to this ethical dilemma. Finally, a methodology is devised to answer the question of whether the variant-specific epidemic of AIDS caused by HIV-1 can be cured via artificially inducing immunity by CRISPR-Cas9.

Legacy of a magic gene-CCR5-∆32: From discovery to clinical benefit in a generation.

The discovery of the 32-bp deletion allele of the chemokine receptor gene CCR5 showed that homozygous carriers display near-complete resistance to HIV infection, irrespective of exposure. Algorithms of molecular evolutionary theory suggested that the CCR5-∆32 mutation occurred but once in the last millennium and rose by strong selective pressure relatively recently to a ~10% allele frequency in Europeans. Several lines of evidence support the hypothesis that CCR5-∆32 was selected due to its protective influence to resist Yersinia pestis, the agent of the Black Death/bubonic plague of the 14th century. Powerful anti-AIDS entry inhibitors targeting CCR5 were developed as a treatment for HIV patients, particularly those whose systems had developed resistance to powerful anti-retroviral therapies. Homozygous CCR5-∆32/∆32 stem cell transplant donors were used to produce HIV-cleared AIDS patients in at least five "cures" of HIV infection. CCR5 has also been implicated in regulating infection with Staphylococcus aureus, in recovery from stroke, and in ablation of the fatal graft versus host disease (GVHD) in cancer transplant patients. While homozygous CCR5-∆32/32 carriers block HIV infection, alternatively they display an increased risk for encephalomyelitis and death when infected with the West Nile virus.

Polymorphisms of CCR5, IL-6, IFN-γ and IL-10 genes in Cuban HIV/AIDS patients.

INTRODUCTION: Genetic studies have shown associations of several single nucleotide polymorphisms (SNP) with different rates of progression and variation in susceptibility to HIV infection. This study aimed to estimate the frequency of ccr5Δ32, IL-6-174G/C, IFN-γ+874T/A and IL-10-1082A/G polymorphisms in Cuban HIV-infected patients and a group of sero-discordant couples to assess their influence on risk and disease progression. METHODS: A cross-sectional study was carried out on 120 subjects registered at the Institute of Tropical Medicine «Pedro Kour¼ (IPK) and the Ameijeiras Hospital from June 2018 until December 2019. The amplification of fragments of the ccr5, IL-6, IFN-γ and IL-10 genes was performed by polymerase chain reaction followed by identification of polymorphisms using the restriction fragment length polymorphism analysis for IL-6 with the restriction enzymes Nla III. Amplification Refractory Mutation System was used for IFN-γ and IL-10 genes. RESULTS: The allelic and genotypic distributions of the genes ccr5, IL-6, IFN-γ and IL-10 did not differ significantly between the two groups. Cell counts and plasma viral load values did not differ significantly between genotypes of the ccr5, IL-6, IFN-γ and IL-10 genes. Only the IL-6 GC genotype was associated with higher viral load values. The combination of alleles of the four considered SNPs showed a highly significant increase in the risk of HIV infection for one of them, but with a very low frequency (<1%). CONCLUSION: This study contributes to evaluating the frequency of these polymorphisms and their influence on biomarkers of the progression of HIV infection in the Cuban HIV-population.

Association of TREX1 polymorphism with disease progression in human immunodeficiency virus type-1 (HIV-1) infected patients.

The time interval between HIV-1 infection and AIDS development is not the same in all patients and depends largely on the genetic background of the individual. Polymorphisms in the TREX1 gene, the main enzyme in the clearance of cytosolic DNA, affect type 1 interferon-mediated inflammatory response in HIV-1 infection. We aimed to study the role of a single nucleotide polymorphism (rs3135941) of the TREX1 gene and the rate of disease progression in patients infected with HIV-1. A total of 190 HIV-1 infected patients were recruited. Patients' demographic and laboratory data including CD4 counts, viral load, and antiretroviral therapy (ART) were collected. The genotype of rs3135941 was determined by a PCR-SSP method. The rate of progression to AIDS was calculated with Kaplan-Meier survival analysis using Stata software. The patients were divided into rapid and slow progressors based on time interval of CD4 drop below 350/µl. Kaplan-Meier analysis revealed an accelerated disease progression in patients with TC and CC genotypes (HR = 1.49, 95% CI = 1.01-2.17). The mean values of the first 5-year CD4 counts were significantly different in patients who had CC and TC genotypes compared to the TT group (p = 0.036). The result of this study emphasizes the importance of TREX1 polymorphism in HIV-1 progression. These data warrant further investigation into the role of other polymorphisms of TREX1.

Biomedical association analysis between G2/M checkpoint genes and susceptibility to HIV-1 infection and AIDS progression from a northern chinese MSM population.

BACKGROUND: MSM are at high risk of HIV infection. Previous studies have shown that the cell cycle regulation plays an important role in HIV-1 infection, especially at the G2/M checkpoint. ATR, Chk1, Cdc25C and CDK1 are key genes of G2/M checkpoint. However, the association between SNPs of these genes and susceptibility to HIV-1 infection and AIDS progression remains unknown. METHODS: In this study, 42 tSNPs from the above four G2/M checkpoint genes were genotyped in 529 MSM and 529 control subjects from northern China to analyze this association. RESULTS: The results showed that rs34660854 A and rs75368165 A in ATR gene and rs3756766 A in Cdc25C gene could increase the risk of HIV-1 infection (P = 0.049, OR = 1.234, 95% CI 1.001-1.521; P = 0.020, OR = 1.296, 95% CI 1.042-1.611; P = 0.011, OR = 1.392, 95% CI 1.080-1.794, respectively), while Chk1 rs10893405 (P = 0.029, OR = 1.629, 95% CI 1.051-2.523) were significantly associated with AIDS progression. Besides, rs34660854 (P = 0.019, OR = 1.364, 95% CI 1.052-1.769; P = 0.022, OR = 1.337, 95% CI 1.042-1.716, under Codominant model and Dominant model, respectively) and rs75368165 (P = 0.006, OR = 1.445, 95% CI = 1.114-1.899; P = 0.007, OR = 1.418, 95% CI 1.099-1.831, under Codominant model and Dominant model, respectively) in ATR gene, rs12576279 (P = 0.013, OR = 0.343, 95% CI 0.147-0.800; P = 0.048, OR = 0.437, 95% CI 0.192-0.991, under Codominant model and Dominant model, respectively) and rs540436 (P = 0.012, OR = 1.407, 95% CI 1.077-1.836; P = 0.021, OR = 1.359, 95% CI 1.048-1.762, under Codominant model and Dominant model, respectively) in Chk1 gene, rs3756766 (P = 0.013, OR = 1.455, 95% CI 1.083-1.954; P = 0.009, OR = 1.460, 95% CI 1.098-1.940, under Codominant model and Dominant model, respectively) in Cdc25C gene and rs139245206 (P = 0.022, OR = 5.011, 95% CI 1.267-19.816; P = 0.020, OR = 5.067, 95% CI 1.286-19.970, under Codominant model and Recessive model, respectively) in CDK1 gene were significantly associated with HIV-1 infection under different models. CONCLUSIONS: We found that genetic variants of G2/M checkpoint genes had a molecular influence on the occurrence of HIV-1 infection and AIDS progression in a northern Chinese MSM population.

Targeted delivery methods for RNA interference are necessary to obtain a potential functional cure for HIV/AIDS.

Ribonucleic acid (RNA) is of great interest in many different therapeutic areas including infectious diseases such as immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Thanks to current, advanced treatments for HIV, the diagnosis is no longer a death sentence. However, even with these treatments, latency is suggested to persist in T-lymphocyte-rich tissues including gut-associated lymphatic tissue (GALT), spleen, and bone marrow making HIV an incurable disease. Therefore, it is important to design systems that can effectively deliver therapeutics to these tissues to fight latent infection and find a functional cure. Numerous therapeutics ranging from small molecules to cell therapies have been explored as a cure for HIV but have failed to maintain therapeutic longevity. RNA interference (RNAi) provides a unique opportunity to achieve a functional cure for those who suffer from chronic HIV/AIDS by suppressing replication of the virus. However, RNA has certain imitations in delivery as it cannot be delivered without a carrier due to its negative charge and degradation from endogenous nucleases. Here, we provide a detailed analysis of explored systems for siRNA delivery for HIV/AIDS in the context of RNA therapeutic design and nanoparticle design. In addition, we suggest strategies that should be used to target specific tissues that are rich in lymphatic tissue.

Treatment with Antiviral Drugs Will Significantly Inhibit the HIV-1 RNA POL Gene Expression and Viral Load in AIDS Patients.

Objective: This study is to investigate the difference in HIV-1 RNA pol gene expression in AIDS patients before and after antiviral treatment and its effect on the expression level of CD4+/CD8+ T cells in peripheral blood. Methods: The participants included 200 AIDS patients who had undergone antiviral medication, and the quantity of HIV-1 RNA pol gene was determined using nested polymerase chain reaction (nPCR). The levels of CD3+, CD4+, and CD8+ T lymphocytes in peripheral blood were measured by flow cytometry before and after therapy. The receiver operating characteristics (ROC) curve was used to assess the impact of HIV-1 RNA pol gene expression and the CD4+/CD8+ ratio on the prognosis of AIDS patients. Results: After three months of therapy, the levels of HIV-1 RNA and viral load in the patients showed a drastic decline, while the levels of CD4+/CD8+ were markedly elevated (P < 0.05). Logistic analysis revealed that patients' viral loads were positively correlated with HIV-1 RNA and negatively correlated with CD4+/CD8+ (P < 0.05). The alanine aminotransferase (ALT), white blood cell (WBC) count, Serum creatinine (Cr), total cholesterol (TC), triglyceride (TG), and platelet (PLT) levels significantly increased following a 24-month therapy, while no significant changes were observed in the level of aspartate aminotransferase (AST), red blood cell (RBC), and neutrophil (NEU) (%). (P > 0.05). Conclusion: Antiviral drugs significantly inhibit the HIV-1 RNA POL gene expression and viral load in AIDS patients but upregulate the expression level of CD4+/CD8+ T cells in peripheral blood.

CCR5∆32 and SDF1 3'A: Gene Variants, Expression and Influence on Biological Markers for the Clinical Progression to AIDS among HIV-1 Virus Controllers in a Mixed Population of the Amazon Region of Brazil.

CCR5Δ32 and SDF1-3'A polymorphisms were investigated in a cohort of viremia controllers, without the use of therapy, along with their influence on CD4+ T lymphocytes (TLs), CD8+ TLs, and plasma viral load (VL). The samples were analyzed from 32 HIV-1-infected individuals classified as viremia controllers 1 and 2 and viremia non-controllers, from both sexes, mostly heterosexuals, paired with 300 individuals from a control group. CCR5∆32 polymorphism was identified by PCR amplification of a fragment of 189 bp for the wild-type allele and 157 bp for the allele with the ∆32 deletion. SDF1-3'A polymorphism was identified by PCR, followed by enzymatic digestion (restriction fragment length polymorphism) with the Msp I enzyme. The relative quantification of gene expression was performed by real-time PCR. The distribution of allele and genotype frequencies did not show significant differences between the groups. The gene expression of CCR5 and SDF1 was not different between the profiles of AIDS progression. There was no significant correlation between the progression markers (CD4+ TL/CD8+ TL and VL) and the CCR5∆32 polymorphism carrier status. The 3'A allele variant was associated with a marked loss of CD4+ TLs and a higher plasma VL. Neither CCR5∆32 nor SDF1-3'A was associated with viremia control or the controlling phenotype.

VIH/sida y epigenética / HIV/AIDS and epigenetic

Resumen Desde 1981, el virus de la inmunodeficiencia humana ha afectado a más de 75 millones de personas en el mundo. La prevención, el diagnóstico temprano y, ante todo el empleo de la terapia antirretroviral, ha disminuido su morbimortalidad. Sin embargo, su cura y el desarrollo de una vacuna efectiva aún son objetivos no alcanzables a corto plazo. Una de las barreras para obtener su control es la persistencia crónica de los virus o sus subproductos en los denominados reservorios celulares, lo que induce un proceso inflamatorio crónico complejo que se manifiesta clínicamente como enfermedad cardiovascular, diversos tipos de cáncer, envejecimiento precoz, entre otras patologías. Los procesos intrínsecos que llevan a estos trastornos han estado siendo investigados a profundidad en los últimos años y la epigenética, definida como el estudio de las modificaciones que afectan de manera directa la expresión de los genes, pero sin cambios en la secuencia del ácido desoxirribonuncleico, puede ayudar a desentrañar estos retos. En esta revisión se analizan los mecanismos epigenéticos, como la metilación del ácido desoxirribonuncleico, las modificaciones en histonas y el ácido ribonucleico no codificante, como posibles blancos en el diagnóstico y tratamiento de la inflamación crónica y sus consecuencias clínicas asociadas al virus de inmunodeficiencia humana/sida.

Abstract Since 1981, over 75 million people have been infected with human immunodeficiency virus. The survival rate of patients with this infection has dramatically increased with the use of antiretroviral therapy, and this therapy significantly reduced the incidence of AIDS defining events. Despite recent progress, neither a cure nor a preventive vaccine against human immunodeficiency virus infection is likely to become available soon. Epigenetics is defined as the study of chemical modifications of intrinsic and extrinsic factors of the genetic code regulating gene expression. Three types of epigenetic markers have been found: DNA methylation, post-translational histone modifications, and non-coding RNA (ncRNA). In this review, we analyzed recent research about the relation between epigenetic mechanisms, the persistence of HIV in host cells, the chronic inflammatory response evoked, the cardiovascular diseases associated and premature aging in this population.

A CRISPR-Cas Cure for HIV/AIDS.

Human immunodeficiency virus (HIV) infections and HIV-induced acquired immunodeficiency syndrome (AIDS) continue to represent a global health burden. There is currently no effective vaccine, nor any cure, for HIV infections; existing antiretroviral therapy can suppress viral replication, but only as long as antiviral drugs are taken. HIV infects cells of the host immune system, and it can establish a long-lived viral reservoir, which can be targeted and edited through gene therapy. Gene editing platforms based on the clustered regularly interspaced palindromic repeat-Cas system (CRISPR-Cas) have been recognized as promising tools in the development of gene therapies for HIV infections. In this review, we evaluate the current landscape of CRISPR-Cas-based therapies against HIV, with an emphasis on the infection biology of the virus as well as the activity of host restriction factors. We discuss the potential of a combined CRISPR-Cas approach that targets host and viral genes to activate antiviral host factors and inhibit viral replication simultaneously. Lastly, we focus on the challenges and potential solutions of CRISPR-Cas gene editing approaches in achieving an HIV cure.

Increased Prevalence of Unstable HLA-C Variants in HIV-1 Rapid-Progressor Patients.

HIV-1 infection in the absence of treatment results in progression toward AIDS. Host genetic factors play a role in HIV-1 pathogenesis, but complete knowledge is not yet available. Since less-expressed HLA-C variants are associated with poor HIV-1 control and unstable HLA-C variants are associated with higher HIV-1 infectivity, we investigated whether there was a correlation between the different stages of HIV-1 progression and the presence of specific HLA-C allotypes. HLA-C genotyping was performed using allele-specific PCR by analyzing a treatment-naïve cohort of 96 HIV-1-infected patients from multicentric cohorts in the USA, Canada, and Brazil. HIV-1-positive subjects were classified according to their different disease progression status as progressors (Ps, n = 48), long-term non-progressors (LTNPs, n = 37), and elite controllers (ECs, n = 11). HLA-C variants were classified as stable or unstable according to their binding stability to ß2-microglobulin/peptide complex. Our results showed a significant correlation between rapid progression to AIDS and the presence of two or one unstable HLA-C variants (p-value: 0.0078, p-value: 0.0143, respectively). These findings strongly suggest a link between unstable HLA-C variants both at genotype and at allele levels and rapid progression to AIDS. This work provides further insights into the impact of host genetic factors on AIDS progression.

Association of Polymorphisms in NHEJ Pathway Genes with HIV-1 Infection and AIDS Progression in a Northern Chinese MSM Population.

Background and Aims: Men who have sex with men (MSM) are at high risk of HIV infection. The nonhomologous end joining (NHEJ) pathway is the main way of double-stranded DNA break (DSB) repair in the higher eukaryotes and can repair the DSB timely at any time in cell cycle. It is also indicated that the NHEJ pathway is associated with HIV-1 infection since the DSB in host genome DNA occurs in the process of HIV-1 integration. The aim of the present investigation was to evaluate associations of single-nucleotide polymorphisms (SNPs) in NHEJ pathway genes with susceptibility to HIV-1 infection and AIDS progression among MSM residing in northern China. Methods: A total of 481 HIV-1 seropositive men and 493 HIV-1 seronegative men were included in this case-control study. Genotyping of 22 SNPs in NHEJ pathway genes was performed using the SNPscan™ Kit. Results: Positive associations were observed between XRCC6 rs132770 and XRCC4 rs1056503 genotypes and the susceptibility to HIV-1 infection. In gene-gene interaction analysis, significant SNP-SNP interactions of XRCC6 and XRCC4 genetic variations were found to play a potential role in the risk of HIV-1 infection. In stratified analysis, XRCC5 rs16855458 was significantly associated with CD4+ T cell counts in AIDS patients, whereas LIG4 rs1805388 was linked to the clinical phases of AIDS patients. Conclusions: NHEJ gene polymorphisms can be considered to be risk factors of HIV-1 infection and AIDS progression in the northern Chinese MSM population.

CRISPR-Cas12a-activated palindrome-catalytic hairpin assembly for ultrasensitive fluorescence detection of HIV-1 DNA.

Accurate analysis of HIV DNA is valuable for the diagnosis of AIDS. Herein, an ultrasensitive and specific fluorescence method was developed for HIV-1 DNA detection based on CRISPR-Cas12a-activated palindrome-catalytic hairpin assembly (CRISPR-Cas12a-PCHA). The presence of HIV-1 DNA activated the trans-cleavage activity of CRISPR-Cas12a, which could continuously digest the DNA fragment of hairpins connected to magnetic beads to expose single-stranded RNA. After magnetic separation, the exposed RNA triggered multiple PCHA reactions, generating many Y-shaped DNA structures that were self-assembled into the DNA superstructures via the hybridization of palindromic sticky ends, leading to the release of amounts of fluorescence signal. Different from the reported recently biosensing strategies of nucleic acid amplification technologies-activated CRISPR-Cas12a, CRISPR-Cas12a-PCHA endowed the strategy with unique advantages of simple sample pretreatment, direct duplex target detection, and ultrahigh sensitivity. The strategy was able to resist the interference of the complex matrix in real sample and distinguish between HIV patients and healthy persons. Thus, the method is a promising tool for ultrasensitive and specific detection of HIV-1 DNA for AIDS diagnosis.

Epidemiology-based Analysis of Characteristics of Dual Infection of Tuberculosis /Acquired Immune Deficiency Syndrome (AIDS) and Drug Resistance Mechanism of Related Genes.

This research was to explore the population characteristics and drug-resistant gene mutations of tuberculosis (TB) and human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) dual infection population, and to provide a reference for clinical screening and prevention of TB/HIV dual infection. TB patients and HIV-infected/AIDS patients registered in Fuzhou Center for Disease Control and Prevention were selected as research subjects. The population characteristics of TB/HIV dual infection and mutation of drug-resistant genes were discussed. It was found that TB patients aged 20-40 years had the highest HIV infection rate, followed by those aged over 40 years. The rate of HIV infection in smear-negative TB patients was higher than that in smear-positive TB patients. HIV/AIDS patients aged 20-40 had the highest TB infection rate. In addition, men had higher rates of HIV than women, and married people had lower rates of HIV than single people. Mycobacterium tuberculosis (MTB) had the highest resistance to isoniazid (42.86%), followed by ofloxacin (34.82%), streptomycin (33.81%), and rifampicin (32.15%). Among the 113 cases of multi-drug resistant strains, 82 cases had mutations in the rpoB gene, with a gene mutation rate of 55.75%. The mutations ranged from codon 511 to codon 569. A total of 31 cases had mutations in the katG/inhA gene. Of which, there were 17 cases of katG single gene mutation, 9 cases of inhA single gene mutation, and 5 cases of combined katG and inhA gene mutation. It was suggested that it was necessary to carry out key TB/HIV two-way screening for TB patients older than 40 years old/smear-negative and male, single, and HIV-infected/AIDS patients aged 20-40. The resistance of MTB to antiTB drugs in this area was generally high, and the drug resistance of retreated patients was significantly higher than that of newly treated patients. Among the resistance genes, the rpoB gene had the highest mutation frequency, followed by the katG gene and inhA gene.

Clinical parameters, selected HLA and chemokine gene variants associated with late presentation into care of people living with HIV/AIDS.

INTRODUCTION: Late presentation into care remains a significant problem in the diagnosis of HIV infection, and may negatively impact the Joint United Nations Program HIV/AIDS elimination targets. Host genetics affects the tempo of HIV disease progression and therefore may influence clinical status at care entry. MATERIALS AND METHODS: Longitudinal data were collected for 863 Caucasian patients followed up at Pomeranian Medical University, Szczecin, Poland. Single nucleotide polymorphisms in CCR2 (rs1799864), CX3CR1 (rs3732378), HLAC-35 (rs9264942), CCR5 promoter (rs1799988) as well as 32 base pair CCR5 mutation and HLA-B*5701 genotypes were correlated with the clinical and immunologic patient status at care entry. Late presentation was defined as baseline CD4 lymphocyte count <350 cells/µL or history of AIDS-defining illness, while advanced HIV disease as baseline CD4 lymphocyte count <200 cells/µL or AIDS. RESULTS: Of the analyzed gene variants, the CCR2 (rs1799864) GG genotype was more frequent among patients presenting for care with a CD4 lymphocyte count <200/µL (82.6% for GG homozygotes vs. 74.5% for allele A carriers, p = 0.01). The presence of the heterozygous wt/Δ32 genotype at the CCR5 gene was associated with a higher frequency of asymptomatic infection (18.9% for wt/Δ32 heterozygotes vs. 12% for wt/wt homozygotes, p = 0.03). As expected, this association was also observed among late presenters compared to patients presenting for care earlier (13.7% vs. 19,7%, respectively, p = 0.04). Finally, HLA-B*5701 was less common among late presenters (5%) compared to patients who entered care early (9.6%, p = 0.01) or patients with advanced HIV disease (8.9% vs. 5.2%, p = 0.02). CONCLUSIONS: Late presentation was associated with the GG homozygous genotype at the CCR2 rs1799864 SNP, while both the HLA-B*5701 variant and the CCR5 wt/Δ32 were associated with more favorable clinical profile at care entry.

Prevalence and genetic characteristics of Blastocystis hominis and Cystoisospora belli in HIV/AIDS patients in Guangxi Zhuang Autonomous Region, China.

Blastocystis hominis and Cystoisospora belli are considered to be common opportunistic intestinal protozoa in HIV/AIDS patients. In order to investigate the prevalence and genetic characteristics of B. hominis and C. belli in HIV/AIDS patients, a total of 285 faecal samples were individually collected from HIV/AIDS patients in Guangxi, China. B. hominis and C. belli were investigated by amplifying the barcode region of the SSU rRNA gene and the internal transcribed spacer 1 (ITS-1) region of the rRNA gene, respectively. Chi-square test or Fisher's exact test were conducted to assess the risk factors related to B. hominis and C. belli infection. The prevalence of B. hominis and C. belli was 6.0% (17/285) and 1.1% (3/285) respectively. Four genotypes of B. hominis were detected, with ST3 (n = 8) and ST1 (n = 6) being predominant, followed by ST6 (n = 2) and ST7 (n = 1). Females had a statistically higher prevalence of B. hominis (11.6%) than males (4.2%). The statistical analysis also showed that the prevalence of B. hominis was significantly associated with age group and educational level. Our study provides convincing evidence for the genetic diversity of B. hominis, which indicates its potential zoonotic transmission and is the first report on the molecular characteristics of C. belli in HIV/AIDS patients in China.

Recent developments in CCR5 regulation for HIV cure.

Acquired immunodeficiency syndrome (AIDS) has affected millions of people worldwide. The human immunodeficiency virus (HIV) which infects T cells by using CD4 as its main receptor. Currently different treatments are available against HIV infection which can improve life expectancy of the patient but still it remains incurable. CCR5, which is also required as a co-receptor by majority of HIV strains for entry into the target cells, is now being targeted for gene therapy to develop HIV resistance in patients. In this review, we discuss different strategies that are being adapted for CCR5-gene disruption in CD4+ T cells and in hematopoietic stem cells (HSCs) to generate a HIV-resistant immune system in infected individuals. If CCR5 gene that can shape HIV-resistant T cells, it will aim in new approaches in clinical trials. But these techniques have certain weaknesses and disadvantages, and will need to be paired with other strategies to form a full HIV remedy. There is also a need to establish methods to help deter HIV re-emergence following targeted CCR5 therapy. But ultimately, this brought us a better knowledge of the road to HIV treatment.

CD4 receptor diversity represents an ancient protection mechanism against primate lentiviruses.

Infection with human and simian immunodeficiency viruses (HIV/SIV) requires binding of the viral envelope glycoprotein (Env) to the host protein CD4 on the surface of immune cells. Although invariant in humans, the Env binding domain of the chimpanzee CD4 is highly polymorphic, with nine coding variants circulating in wild populations. Here, we show that within-species CD4 diversity is not unique to chimpanzees but found in many African primate species. Characterizing the outermost (D1) domain of the CD4 protein in over 500 monkeys and apes, we found polymorphic residues in 24 of 29 primate species, with as many as 11 different coding variants identified within a single species. D1 domain amino acid replacements affected SIV Env-mediated cell entry in a single-round infection assay, restricting infection in a strain- and allele-specific fashion. Several identical CD4 polymorphisms, including the addition of N-linked glycosylation sites, were found in primate species from different genera, providing striking examples of parallel evolution. Moreover, seven different guenons (Cercopithecus spp.) shared multiple distinct D1 domain variants, pointing to long-term trans-specific polymorphism. These data indicate that the HIV/SIV Env binding region of the primate CD4 protein is highly variable, both within and between species, and suggest that this diversity has been maintained by balancing selection for millions of years, at least in part to confer protection against primate lentiviruses. Although long-term SIV-infected species have evolved specific mechanisms to avoid disease progression, primate lentiviruses are intrinsically pathogenic and have left their mark on the host genome.

HIV suppressors against LINE-1: one functions as two.

Exogenous retroviruses are RNA viruses that require reverse transcription for their replication. Among these viruses, human immunodeficiency virus (HIV) is infectious to humans and causes the development of acquired immune deficiency syndrome (AIDS). There are also endogenous retroelements that require reverse transcription for their retrotransposition, among which the type 1 long interspersed element (LINE-1) is the only type of retroelement that can replicate autonomously. It was once believed that retroviruses like HIV and retroelements like LINE-1 share similarities in processes such as reverse transcription and integration. Accordingly, many HIV suppressors are also potent LINE-1 inhibitors. However, in many cases, one suppressor uses two or more distinct mechanisms to repress HIV and LINE-1. In this review, we discuss some of these suppressors, focusing on their alternative mechanisms opposing the replication of HIV and LINE-1. Based on the differences in HIV and LINE-1 activity, the subcellular localization of these suppressors, and the impact of LINE-1 retrotransposition on human cells, we propose possible reasons for the inhibition of HIV and LINE-1 through different pathways by these suppressors, with the hope of accelerating future studies in associated research fields.

Two Human Monoclonal HLA-Reactive Antibodies Cross-React with Mamu-B*008, a Rhesus Macaque MHC Allotype Associated with Control of Simian Immunodeficiency Virus Replication.

MHC class I molecules play an important role in adaptive immune responses against intracellular pathogens. These molecules are highly polymorphic, and many allotypes have been characterized. In a transplantation setting, a mismatch between MHC allotypes may initiate an alloimmune response. Rhesus macaques (Macaca mulatta, Mamu) are valuable as a preclinical model species in transplantation research as well as to evaluate the safety and efficacy of vaccine candidates. In both lines of research, the availability of nonhuman primate MHC-reactive mAbs may enable in vitro monitoring and detection of presence of particular Mamu molecules. In this study, we screened a collection of thoroughly characterized HLA class I-specific human mAbs for cross-reactivity with rhesus macaque MHC class I allotypes. Two mAbs, OK4F9 and OK4F10, recognize an epitope that is defined by isoleucine (I) at amino acid position 142 that is present on the Indian rhesus macaque Mamu-B*008:01 allotype, which is an allotype known to be associated with elite control of SIV replication. The reactive pattern of a third mAb, MUS4H4, is more complex and includes an epitope shared on Mamu-A2*05:01 and -B*001:01-encoded Ags. This is the first description, to our knowledge, of human HLA-reactive mAbs that can recognize Mamu allotypes, and these can be useful tools for in vitro monitoring the presence of the relevant allelic products. Moreover, OK4F9 and OK4F10 can be powerful mAbs for application in SIV-related research.