Role of CXCR4 in HIV infection and its potential as a therapeutic target

Analysis of HSV1/2 Infection Reveals an Association between HSV-2 Reactivation and Pregnancy

The herpes simplex viruses consist of the strains, HSV-1 and HSV-2, which are prevalent worldwide and lack a definitive cure. We aimed to explore the specific characteristics of HSV 1 and 2 infections, such as differences between gender assigned at birth, age at infection, site of infection, comorbidities, and effect of pregnancy, through a data analysis. Between 2011 and 2018, the Israeli Central Virology Laboratory diagnosed 9189 samples using multiplexed real-time PCR. In addition, we extracted all of the medical data for 287 females hospitalized at the Sheba Medical Center with HSV-1 (161) or HSV-2 (126) genital infections. HSV-2 was almost absent in the orofacial samples from both genders, while in other lesion sites, HSV-2 was significantly more abundant in females than in males (p < 0.05,). HSV-2 was initially detected at puberty. In the hospitalized females' malignancies, both HSV-1 and HSV-2 were found with a non-significant difference. Simultaneously, pregnancies were more common in females who were HSV-2-positive compared with those who were HSV-1-positive (27.8% vs. 12.4%, respectively, p < 0.01). Primary infections occur more with HSV-1 than with HSV-2 (15.6% vs. 3.2%, respectively). Our findings demonstrate that genital HSV-2 infection episodes are more frequent during pregnancy, suggesting that pregnancy may serve as a risk factor for HSV-2 reactivation or infection.

Giant primary intracranial multi-fossa leiomyosarcoma involving the frontal sinus, ethmoid air cells, anterior fossa, middle fossa, and intraventricular space: A case report and literature review

Background

Leiomyosarcomas (LMSs) is a type of sarcoma that arises from smooth muscle and generally presents in the abdomen. Although intracranial LMS has been identified before, most reported presentations have been in immunocompromised patients. Here, we present an intracranial LMS in an immunocompetent patient.

Case Description

A 22-year-old male with a history of an atypical pineal parenchymal tumor of intermediate differentiation resected by suboccipital craniotomy at the age of 12 followed by adjuvant radiation therapy, presented with 3 weeks of decreased appetite, weight loss, and lethargy. He subsequently underwent transbasal approach skull base tumor resection. Histologic examination of the mass along with the patient's history of radiation was supportive of a low-grade, radiation-induced LMS arising from the anterior fossa of the skull or meninges and extends to the frontal sinus and ethmoid air cells.

Conclusion

Primary intracranial LMS is an extremely rare diagnosis and presenting symptoms vary with the location and size of the tumor. Due to the poor specificity of clinical symptoms, diagnosis is often based on histology. The most common treatment is surgical resection. Adjuvant chemotherapy with various agents has been found to be somewhat effective outside the central nervous system. When LMS does occur, a history of immunocompromised state or previous radiation exposure is often present. Pathological confirmation is required for an appropriate diagnosis.

Machine intelligence-guided selection of optimized inhibitor for human immunodeficiency virus (HIV) from natural products

The human immunodeficiency virus (HIV) connects to the cluster of differentiation (CD4) and any of the entry co-receptors (CCR5 and CXCR4); followed by unloading the viral genome, reverse transcriptase, and integrase enzymes within the host cell. The co-receptors facilitate the entry of virus and vital enzymes, leading to replication and pre-maturation of viral particles within the host. The protease enzyme transforms the immature viral vesicles into the mature virion. The pivotal role of co-receptors and enzymes in homeostasis and growth makes the crucial target for anti-HIV drug discovery, and the availability of X-ray crystal structures is an asset. Here, we used the machine intelligence-driven framework (A-HIOT) to identify and optimize target-based potential hit molecules for five significant protein targets from the ZINC15 database (natural products dataset). Following validation with dynamic motion behavior analysis and molecular dynamics simulation, the optimized hits were evaluated using in silico ADMET filtration. Furthermore, three molecules were screened, optimized, and validated: ZINC00005328058 for CCR5 and protease, ZINC000254014855 for CXCR4 and integrase, and ZINC000000538471 for reverse transcriptase. In clinical trials, the ZINC000254014855 and ZINC000254014855 were passed in primary screens for vif-HIV-1, and we reported the specific receptor as well as interactions. As a result, the validated molecules may be investigated further in experimental studies targeting specific receptors in order to design and synergize an anti-HIV regimen.

The Effect of Microbubble-Assisted Ultrasound on Molecular Permeability across Cell Barriers

The combination of ultrasound and microbubbles (USMB) has been applied to enhance drug permeability across tissue barriers. Most studies focused on only one physicochemical aspect (i.e., molecular weight of the delivered molecule). Using an in vitro epithelial (MDCK II) cell barrier, we examined the effects of USMB on the permeability of five molecules varying in molecular weight (182 Da to 20 kDa) and hydrophilicity (LogD at pH 7.4 from 1.5 to highly hydrophilic). Treatment of cells with USMB at increasing ultrasound pressures did not have a significant effect on the permeability of small molecules (molecular weight 259 to 376 Da), despite their differences in hydrophilicity (LogD at pH 7.4 from -3.2 to 1.5). The largest molecules (molecular weight 4 and 20 kDa) showed the highest increase in the epithelial permeability (3-7-fold). Simultaneously, USMB enhanced intracellular accumulation of the same molecules. In the case of the clinically relevant anti- C-X-C Chemokine Receptor Type 4 (CXCR4) nanobody (molecular weight 15 kDa), USMB enhanced paracellular permeability by two-fold and increased binding to retinoblastoma cells by five-fold. Consequently, USMB is a potential tool to improve the efficacy and safety of the delivery of drugs to organs protected by tissue barriers, such as the eye and the brain.

Discovery of non-peptide small molecular CXCR4 antagonists as anti-HIV agents: Recent advances and future opportunities

CXCR4 plays vital roles in HIV-1 life cycle for it's essential in mediating the interaction of host and virus and completing the entry process in the lifecycle of HIV-1 infection. Compared with some traditional targets, CXCR4 provides a novel and less mutated drug target in the battle against AIDS. Its antagonists have no cross resistance with other antagonists. Great achievements have been made recent years and a number of small molecular CXCR4 antagonists with diversity scaffolds have been discovered. In this review, recent advances in the discovery of CXCR4 antagonists with special attentions on their evolution and structure-activity relationships of representative CXCR4 antagonists are described. Moreover, some classical medicinal chemistry strategies and novel methodologies are also introduced.

Discovery of novel N-aryl piperazine CXCR4 antagonists

A novel series of CXCR4 antagonists with substituted piperazines as benzimidazole replacements is described. These compounds showed micromolar to nanomolar potency in CXCR4-mediated functional and HIV assays, namely inhibition of X4 HIV-1(IIIB) virus in MAGI-CCR5/CXCR4 cells and inhibition of SDF-1 induced calcium release in Chem-1 cells. Preliminary SAR investigations led to the identification of a series of N-aryl piperazines as the most potent compounds. Results show SAR that indicates type and position of the aromatic ring, as well as type of linker and stereochemistry are significant for activity. Profiling of several lead compounds showed that one (49b) reduced susceptibility towards CYP450 and hERG, and the best overall profile when considering both SDF-1 and HIV potencies (6-20 nM).

miR-146a controls CXCR4 expression in a pathway that involves PLZF and can be used to inhibit HIV-1 infection of CD4(+) T lymphocytes

MicroRNA miR-146a and PLZF are reported as major players in the control of hematopoiesis, immune function and cancer. PLZF is described as a miR-146a repressor, whereas CXCR4 and TRAF6 were identified as miR-146a direct targets in different cell types. CXCR4 is a co-receptor of CD4 molecule that facilitates HIV-1 entry into T lymphocytes and myeloid cells, whereas TRAF6 is involved in immune response. Thus, the role of miR-146a in HIV-1 infection is currently being thoroughly investigated. In this study, we found that PLZF mediates suppression of miR-146a to control increases of CXCR4 and TRAF6 protein levels in human primary CD4(+) T lymphocytes. We show that miR-146a upregulation by AMD3100 treatment or PLZF silencing, decreases CXCR4 protein expression and prevents HIV-1 infection of leukemic monocytic cell line and CD4(+) T lymphocytes. Our findings improve the prospects of developing new therapeutic strategies to prevent HIV-1 entry via CXCR4 by using the PLZF/miR-146a axis.

The two human CXCR4 isoforms display different HIV receptor activities: consequences for the emergence of X4 strains

CXCR4 is a chemokine receptor that plays key roles with its specific ligand, CXCL12, in stem cell homing and immune trafficking. It is also used as a coreceptor by some HIV-1 strains (X4 strains), whereas other strains (R5 strains) use an alternative coreceptor, CCR5. X4 strains mainly emerge at late stages of the infection and are linked to disease progression. Two isoforms of this coreceptor have been described in humans: CXCR4-A and CXCR4-B, corresponding to an unspliced and a spliced mRNA, respectively. In this study, we show that CXCR4-B, but not CXCR4-A, mediates an efficient HIV-1 X4 entry and productive infection. Yet, the chemotactic activity of CXCL12 on both isoforms was similar. Furthermore, HIV-R5 infection favored CXCR4-B expression over that of CXCR4-A. In vitro infection with an R5 strain increased CXCR4-B/CXCR4-A mRNA ratio in PBMCs, and this ratio correlated with HIV RNA plasma level in R5-infected individuals. In addition, the presence of the CXCR4-B isoform favored R5 to X4 switch more efficiently than did CXCR4-A in vitro. Hence, the predominance of CXCR4-B over CXCR4-A expression in PBMCs was linked to the ability of circulating HIV-1 strains to use CXCR4, as determined by genotyping. These data suggest that R5 to X4 switch could be favored by R5 infection-induced overexpression of CXCR4-B. Finally, we achieved a specific small interfering RNA-mediated knockdown of CXCR4-B. This represents a proof of concept for a possible gene-therapeutic approach aimed at blocking the HIV coreceptor activity of CXCR4 without knocking down its chemotactic activity.

G protein-coupled receptors revisited: therapeutic applications inspired by synthetic biology

G protein-coupled receptors (GPCRs) mediate the majority of cellular responses to hormones and neurotransmitters within the human body. They have much potential in the emerging field of synthetic biology, which is the rational, systematic design of biological systems with desired functionality. The responsiveness of GPCRs to a plethora of endogenous and exogenous ligands and stimuli make them ideal sensory receptor modules of synthetic gene networks. Such networks can activate target gene expression in response to a specific stimulus. Additionally, because GPCRs are important pharmacological targets of various human diseases, genes encoding their protein/peptide ligands can also be incorporated as target genes of the response output elements of synthetic gene networks. This review aims to critically examine the potential role of GPCRs in constructing therapeutic synthetic gene networks and to discuss various challenges in utilizing GPCRs for synthetic biology applications.

In vivo effect of statins on the expression of the HIV co-receptors CCR5 and CXCR4

BACKGROUND

During the HIV-1 replication cycle, several molecules including chemokine receptors and cholesterol are crucial, and are therefore potential targets for therapeutic intervention. Indeed statins, compounds that inhibit cellular synthesis of cholesterol and have anti-inflammatory and immunomodulatory properties were shown to inhibit HIV-1 infection by R5 tropic strains but not by X4 strains in vitro, mainly by altering the chemokine receptor/ligands axes. Therefore, the objective of this study was to characterize in vivo, the capacity of statins to modulate in HIV seronegative and chronically HIV-1-infected adults the expression of CCR5 and CXCR4, of their ligands and the tropism of circulating HIV-1 strains.

METHODS

Samples from asymptomatic HIV-1-infected adults enrolled in a clinical trial aimed at evaluating the antiretroviral activity of lovastatin were used to evaluate in vivo the modulation by lovastatin of CCR5, CXCR4, their ligands, and the shift in plasma viral tropism over one year of intervention. In addition, ten HIV negative adults received a daily oral dose of 40 mg of lovastatin or 20 mg of atorvastatin; seven other HIV negative individuals who received no treatment were followed as controls. The frequency and phenotype of immune cells were determined by flow-cytometry; mRNA levels of chemokine receptors and their ligands were determined by real-time PCR. Viral tropism was determined by PCR and sequencing, applying the clonal and clinical model of analyses.

RESULTS

Our study shows that long-term administration of lovastatin in HIV-infected individuals does not induce a shift in viral tropism, or induce a significant modulation of CCR5 and CXCR4 on immune cells in HIV-infected patients. Similar results were found in HIV seronegative control subjects, treated with lovastatin or atorvastatin, but a significant increase in CCL3 and CCL4 transcription was observed in these individuals.

CONCLUSIONS

These findings suggest that long-term administration of statins at therapeutic doses, does not significantly affect the expression of HIV-1 co-receptors or of their ligands. In addition it is important to point out that based on the results obtained, therapeutic administration of statins in HIV-infected patients with lipid disorders is safe in terms of selecting X4 strains.

Potent anti-HIV activities and mechanisms of action of a pine cone extract from Pinus yunnanensis

The anti-HIV activities of a pine cone extract (YNS-PY-F) from Pinus yunnanensis have been evaluated, and its mechanisms of action were also explored. The pine cone extract, YNS-PY-F, potently inhibited HIV-1_IIIB, HIV-1_RF, HIV-1_A17, HIV-1_AO18 and HIV-2_ROD and induced cytopathic effect in C8166 cells with EC₅₀ values of 0.96 μg/mL, 1.53 μg/mL, 0.88 μg/mL, 7.20 μg/mL and 6.17 μg/mL, respectively. The quantification of a p24 production assay showed that YNS-PY-F significantly inhibited the acute replication of HIV-1_IIIB, HIV-1_RF, HIV-1_A17 and HIV-1_AO18 in C8166 cells. An MTT assay showed that YNS-PY-F also significantly inhibited the HIV-1_IIIB induced cytolysis in MT-4 cells with an EC₅₀ value of 2.22 μg/mL. The mechanism assays showed that YNS-PY-F had potent inhibitory effects on the fusion between infected cells and uninfected cells, and the activity of HIV-1 reverse transcriptase, with EC₅₀ values of 7.60 μg/mL and 4.60 μg/mL, respectively. Overall, these data suggest that the pine cone extract from Pinus yunnanensis has potent inhibitory activities against HIV-1_IIIB, HIV-1_RF, RT inhibitor-resistant strains HIV-1_A17 and HIV-1_AO18, and HIV-2_ROD, and its anti-HIV mechanisms include inhibition of HIV entry and inhibition of reverse transcriptase activity.

Purified Timothy grass pollen major allergen Phl p 1 may contribute to the modulation of allergic responses through a pleiotropic induction of cytokines and chemokines from airway epithelial cells

By definition, allergens are proteins with the ability to elicit powerful T helper lymphocyte type 2 (Th2) responses, culminating in immunoglobulin (Ig)E antibody production. Why specific proteins cause aberrant immune responses has remained largely unanswered. Recent data suggest that there may be several molecular paths that may affect allergenicity of proteins. The focus of this study is the response of airway epithelium to a major allergen from Phleum pratense Phl p 1. Instead of focusing on a few genes and proteins that might be affected by the major allergen, our aim was to obtain a broader view on the immune stimulatory capacity of Phl p 1. We therefore performed detailed analysis on mRNA and protein level by using a microarray approach to define Phl p 1-induced gene expression. We found that this allergen induces modulation and release of a broad range of mediators, indicating it to be a powerful trigger of the immune system. We were able to show that genes belonging to the GO cluster 'cell communication' were among the most prominent functional groups, which is also reflected in cytokines and chemokines building centres in a computational model of direct gene interaction. Further detailed comparison of grass pollen extract (GPE)- and Phl p 1-induced gene expression might be beneficial with regard to the application of single components within diagnosis and immunotherapy.

HIV-1 coinfection and morphine coexposure severely dysregulate hepatitis C virus-induced hepatic proinflammatory cytokine release and free radical production: increased pathogenesis coincides with uncoordinated host defenses

Coinfection with human immunodeficiency virus type-1 (HIV-1) and hepatitis C virus (HCV) is a global problem that is more prevalent in injection drug users because they have a higher risk for acquiring both viruses. The roles of inflammatory cytokines and oxidative stress were examined in HIV-1- and HCV-coinfected human hepatic cells. Morphine (the bioactive product of heroin), HIV-1 Tat and the MN strain gp120 (gp120(MN)) proteins, and X4 HIV-1(LAI/IIIB) and R5 HIV-1(SF162) isolates were used to study the mechanisms of disease progression in HCV (JFH1)-infected Huh7.5.1 cell populations. HCV increased tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) release and augmented production of reactive oxygen species (ROS), nitric oxide (NO), and 3-nitrotyrosine (3-NT) in Huh7.5.1 cells. Morphine preferentially affected R5-tropic, but not X4-tropic, HIV-1 interactions with Huh7.5.1 cells. HIV-1 proteins or isolates increased cytokine release in HCV-infected cells, while adding morphine to coinfected cells caused complex imbalances, significantly disrupting cytokine secretion depending on the cytokine, morphine concentration, exposure duration, and particular pathogen involved. Production of ROS, NO, and 3-NT increased significantly in HCV- and HIV-1-coexposed cells while exposure to morphine further increased ROS. The proteasome inhibitor MG132 significantly decreased oxyradicals, cytokine levels, and HCV protein levels. Our findings indicate that hepatic inflammation is increased by combined exposure to HCV and HIV-1, that the ubiquitin-proteasome system and NF-κB contribute to key aspects of the response, and that morphine further exacerbates the disruption of host defenses. The results suggest that opioid abuse and HIV-1 coinfection each further accelerate HCV-mediated liver disease by dysregulating immune defenses.

Analysis of the roles of HIV-derived microRNAs

IMPORTANCE OF THE FIELD

HIV-1 is a retrovirus that has infected millions in recent decades. The level of life cycle complexity and host control exerted by this small virus with only nine proteins is astonishing. An interesting direction that has emerged in recent years is the role of small non-coding RNAs in viral gene expression.

AREAS COVERED IN THIS REVIEW

We focus on HIV-1 produced microRNAs (miRNAs), namely, TAR, Nef and miR-H1, and their roles in HIV-1 biogenesis. The article provides insights into TAR miRNA-mediated downregulation of viral and host gene expression by recruitment of chromatin remodeling components (HDAC1).

WHAT THE READER WILL GAIN

We address the influence of TAR miRNA on host cell cycle progression and apoptosis, and the role of Nef miRNA in the regulation of viral and host gene expression. The review also highlights an intriguing connection between miR-H1 and HIV-1-associated neurological pathogenesis, and the influence of the miRNA machinery in the establishment of latency. In the Expert Opinion section, we analyze the issue of host-based therapeutics against HIV-1 and how transcription inhibitors are influenced by viral miRNA production.

TAKE HOME MESSAGE

HIV-derived miRNAs are of significance not only to understand host-virus interactions, but also for the design of effective therapeutics.