Analysis of CCR5, CCR2, SDF1 and RANTES gene polymorphisms in subjects with HIV-related PML and not determined leukoencephalopathy

Low prevalence of HIV in the northern Cameroon: contribution of some AIDS restriction genes and potential implications for gene therapy

Background

HIV infection and its progression to AIDS depend on several factors including host genetic factors. The immunological mechanisms of host resistance to HIV infection greatly influence the prevalence of HIV in a given region. Worldwide, Cameroon not exempted, the frequency of AIDS-associated genes varies and may influence this prevalence. The North and Far North Regions of Cameroon have had the lowest HIV prevalence in the country for many years despite risky behaviors associated with their customs and habits. In this work, we seek to explore the contribution of host genes to the HIV low prevalence in these regions.

Methodology

Five genes variants previously described as HIV AIDS related were studied. These genes are: CCR5Δ32, CCR5promoter59029G, CCR2-64I, SDF1-3'A and Trim5α(R136Q). A total of 384 consented participants were included in this study. The HIV serological status was confirmed using national algorithm. Genomic DNA was extracted from the buffy coats and used for genotyping. The results obtained were compiled in Excel 2016, Epi Info 7.1 and snpStats software and Chi two tests allowed us to compare the frequencies of the AIDS related alleles in the North with those in other Regions of Cameroon and to measure the impact of these ARGs on protection against HIV.

Results

The frequency of protective alleles CCR5Δ32, CCR5promoter59029G, CCR2-64I, SDF1-3'A and Trim5α(R136Q) was the allelic frequencies should be expressed as percentages i.e. 0.52%; 37.56%; 36.46%; 25.19% and 69.33%. These allelic frequencies exhibited a significant difference when compared to those obtained in other regions of Cameroon (p < 0.01). Protective alleles were predominant in the Northern region compared to others and were associated with resistance to HIV [(p < 0.0001); OR = 2.02 CI, 95%].

Conclusion

The higher frequency of HIV-protective alleles in the northern regions may be a contributing factor to the lower prevalence of HIV. Nevertheless, this should be reinforced by other preventive and surveillance methods to guarantee the sustained low prevalence. HIV can develop resistance through the process of mutation, but the host targets themselves are genetically stable. The study of these host genetic restriction factors is of great value in the design of a practical cure for HIV infection or an effective vaccine.

Prevalence of CCR5 Delta 32 Genetic Variant in the Turkmen Population of Golestan Province, Northeast of Iran

The 32 bp deletion in the chemokine receptor (C-C motif) 5 gene (CCR5Δ32) is a natural loss of function polymorphism that prevents the protein from locating on the cell surface. This genetic variation acts as a double-edge sword in the pathogenesis/defense mechanism of different health conditions, such as viral infections, autoimmune diseases, and cancers. Here, we evaluated the prevalence of the CCR5Δ32 polymorphism in the Turkmen population of Golestan province, northeast of Iran. Blood samples were collected from 400 randomly selected Turkmen populations (199 women and 201 men), and genomic DNA was extracted. Characterization of CCR5Δ32 genotypes was performed by PCR using primers flanking the 32-nucleotide deletion in the CCR5 gene. The amplified DNA fragments were visualized on 2% agarose gel electrophoresis with cybergreen staining under UV light. All individuals were of Turkmen ethnicity and lived in the Golestan province, northeast of Iran. The mean age of all participants was 35.46 years, with a 20-45 year range. All the studied subjects were healthy without any severe conditions such as autoimmune disease and viral infections. All individuals had no history of HIV infection. The PCR product visualization showed that all the samples are at the 330 bp size, which means the CCR5Δ32 allele was utterly absent from the study population. The presence of the CCR5Δ32 allele among Turkmens may be attributed to the admixture with European descent people. We conclude that the CCR5Δ32 polymorphism may be absent in the Iranian Turkmen population, and further studies with a large population are needed.

CC and CXC chemokines play key roles in the development of polyomaviruses related pathological conditions

It has been reported that polyomaviruses are the microbes which can be a cause of several human pathological conditions including cancers, nephropathy, progressive multifocal leukoencephalopathy and gynaecological disease. Although investigators proposed some mechanisms used by the viruses to induce the disorders, the roles played by chemokines in the pathogenesis of polyomaviruses infections are yet to be clarified. This review article investigated recent studies regarding the roles played by chemokines in the pathogenesis of the polyomaviruses infections. The research in the literature revealed that CXC chemokines, including CXCL1, CXCL5, CXCL8, CXCL9, CXCL10, CXCL11, CXCL12 and CXCL16, significantly participate in the pathogenesis of polyomaviruses. CC chemokines, such as CCL2, CCL5 and CCL20 also participate in the induction of the pathological conditions. Therefore, it appears that CXC chemokines may be considered as the strategic factors involved in the pathogenesis of polyomaviruses.

Molecular Biomarkers in Multiple Sclerosis and Its Related Disorders: A Critical Review

Multiple sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system (CNS) which can lead to severe disability. Several diseases can mimic the clinical manifestations of MS. This can often lead to a prolonged period that involves numerous tests and investigations before a definitive diagnosis is reached. As well as the possibility of misdiagnosis. Molecular biomarkers can play a unique role in this regard. Molecular biomarkers offer a unique view into the CNS disorders. They help us understand the pathophysiology of disease as well as guiding our diagnostic, therapeutic, and prognostic approaches in CNS disorders. This review highlights the most prominent molecular biomarkers found in the literature with respect to MS and its related disorders. Based on numerous recent clinical and experimental studies, we demonstrate that several molecular biomarkers could very well aid us in differentiating MS from its related disorders. The implications of this work will hopefully serve clinicians and researchers alike, who regularly deal with MS and its related disorders.

Neuropathogenesis of human immunodeficiency virus infection

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) remain a common end-organ manifestation of viral infection. Subclinical and mild symptoms lead to neurocognitive and behavioral abnormalities. These are associated, in part, with viral penetrance and persistence in the central nervous system. Infections of peripheral blood monocytes, macrophages, and microglia are the primary drivers of neuroinflammation and neuronal impairments. While current antiretroviral therapy (ART) has reduced the incidence of HIV-associated dementia, milder forms of HAND continue. Depression, comorbid conditions such as infectious liver disease, drugs of abuse, antiretroviral drugs themselves, age-related neurodegenerative diseases, gastrointestinal maladies, and concurrent social and economic issues can make accurate diagnosis of HAND challenging. Increased life expectancy as a result of ART clearly creates this variety of comorbid conditions that often blur the link between the virus and disease. With the discovery of novel biomarkers, neuropsychologic testing, and imaging techniques to better diagnose HAND, the emergence of brain-penetrant ART, adjunctive therapies, longer life expectancy, and better understanding of disease pathogenesis, disease elimination is perhaps a realistic possibility. This review focuses on HIV-associated disease pathobiology with an eye towards changing trends in the face of widespread availability of ART.

CCR5-Δ32 gene polymorphism is associated with retinopathy in patients with type 1 diabetes

AIM

The aim of the study was to assess the relationship between the CCR5-Δ32 polymorphism and the risk of diabetic retinopathy (DR) in patients with DM1.

METHODS

We examined 420 patients and 350 healthy controls. The analysis concerned CCR5-Δ32 polymorphism as well as levels of serum inflammatory markers (CRP, TNF-α), adhesion molecules (VCAM, ICAM-1, ICAM-3) and CCR5 ligand (MCP-1).

RESULTS

We found a negative association between DM1 and Δ32 allele. Moreover, the frequency of Δ32 allele was higher in a group with DR in comparison to control subjects without this complication. We also found that Δ32 carriers had the highest levels of: HbA1c, inflammatory markers, adhesion molecules and CCR5 ligand.

CONCLUSIONS

The findings of our studies suggest that the CCR5-Δ32 polymorphism is associated with DM1 such that the Δ32 allele protects against the development of DM1 and increases the risk of DR in patients who have already developed the disease.

Human polyomavirus 6 DNA in the cerebrospinal fluid of an HIV-positive patient with leukoencephalopathy

BACKGROUND

Leukoencephalopathies in HAART-treated, HIV-positive patients include progressive multifocal leukoencephalopathy (PML), a result of lytic infection oligodendrocytes by JC polyomavirus (JCV), and another form characterized by the absence of JCV genome in cerebrospinal fluid (CSF).

OBJECTIVES

To test the potential viral etiology of JCV-negative leukoencephalopathy.

STUDY DESIGN

CSF was collected from 43 HIV-positive patients with MRI suggestive of leukoencephalopathies. DNA was isolated and real-time PCR assays for neurotropic viruses (Herpes Simplex Viruses 1/2, Varicella Zoster Virus, Epstein Barr Virus, Human Cytomegalovirus, Human Herpesvirus 6, JCV and HIV) were conducted. CSF from 14 non-reactive cases were subjected to random nucleic acid amplification, deep sequencing, and in silico search for viral sequences.

RESULTS

JCV genome was detected in the CSF of 19/43 PML patients, HIV genome in the CSF of 5 PML patients including 2 JCV negative patients, and no viruses were detected in 22 patients. Human Polyomavirus 6 (HPyV6) DNA was detected by deep sequencing in one JCV-negative leukoencephalopathy CSF sample.

CONCLUSIONS

HPyV6 DNA was detected in CSF of a case of demyelinating disease. HPyV6 has not been previously reported in CSF or associated with any disease. Demonstrating a causative role will require further studies.

Lack of Correlation Between the CCR5-Δ32 Mutation and Acute Myeloid Leukemia in Iranian Patients

Chemokines and their receptors are crucially important in the pathogenesis of acute myeloblastic leukemia (AML). The CC chemokine receptor 5 (CCR5) is a specific chemokine receptor for CC chemokine ligand 3 (CCL3), CCL4 and CCL5 which all play key roles in identifying cancer properties and localization of leukemia cells. It has been demonstrated that the known mutation in CCR5 gene (CCR5-Δ32) leads to mal-expression of the receptor and affect its function. The aim of this study was to determine the rate of CCR5-Δ32 mutation within Iranian AML patients. In this study, blood samples were obtained from 60 AML patients and 300 healthy controls. The CCR5-Δ32 mutation was evaluated using Gap-PCR technique. Our results showed that CCR5-Δ32 mutation was not found in the patients, while three out of the controls had hetrozygotic form of this mutation. The rest of studied samples had the wild form of the gene. According to these findings, it can probably be concluded that the CCR5-Δ32 is not associated with susceptibility to AML in Iranian patients.

Is the CCR5 Δ 32 mutation associated with immune system-related diseases?

Hypersensitivity and autoimmunity are the main features of immune system-related diseases such as type 2 diabetes (T2D), multiple sclerosis (MS), and asthma. It has been established that chemokines play key roles in the activation and regulation of immune cell migration which is important in the pathogenesis of the diseases mentioned. CC chemokines receptor 5 or CCR5 is a receptor for RANTES, MIP-1α, and MIP-1β and is expressed by several immune cells including NK cells, T lymphocytes, and macrophages. It plays key roles in the regulation of migration and activation of the immune cells during immune responses against microbe and self-antigens during autoimmunity and hypersensitivity disorders. Therefore, any alteration in the sequence of CCR5 gene or in its expression could be associated with immune system-related diseases. Previous studies revealed that a 32-base pair deletion (Δ 32) in exon 1 of the CCR5 gene led to downregulation of the gene. Previous studies demonstrated that not only CCR5 expression was altered in autoimmune and hypersensitivity disorders, but also that the mutation is associated with the diseases. This review addresses the recent information regarding the association of the CCR5 Δ 32 mutation in immune-related diseases including T2D with and without nephropathy, MS, and asthma. Based on the collected data, it seems that the CCR5 Δ 32 mutation can be considered as a risk factor for MS, but not asthma and T2D with and without nephropathy.

CCR5 plays important roles in hepatitis B infection

In humans, hepatitis B virus (HBV) is the most prevalent and the main infectious agent that leads to liver disease. Previous investigations identified that long-term HBV-infected patients are unable to eradicate HBV completely from hepatocytes. The main mechanisms responsible for long-term forms of the infections are yet to be clarified. However, researchers believe that the differences in genetic and immunological parameters in the patients in comparison to subjects who successfully clear HBV infections may be the causes for long-term infection. Previous studies demonstrated that chemokines play important roles in the regulation of immune cell migration and activation, which is crucial for a comprehensive immune response against HBV. RANTES, MIP-1α, and MIP-1β are important CC chemokines which act through CC chemokines receptor 5 (CCR5). This receptor is expressed on several effector immune cells including NK cells, T lymphocytes, and macrophages, and plays a crucial role in the regulation of activation and migration of the immune cells during immune responses against viruses, including HBV. Therefore, alterations in its expression or functions could be associated with attenuated immune responses against HBV. In addition, previous studies identified that a 32 base pair deletion (Δ32) in exon 1, as well as three polymorphisms in the promoter region of the CCR5 gene results in downregulation of the molecule. Previous studies revealed that CCR5 expression was altered in hepatitis B but the role of the CCR5 Δ32 mutation and CCR5 promoter polymorphisms in this disease is controversial. This review addresses the recent information regarding the status of CCR5 expression on immune cells and the association of CCR5 promoter polymorphisms with HBV-infected patients.

Distribution of polymorphisms in cytochrome P450 2B6, histocompatibility complex P5, chemokine coreceptor 5, and interleukin 28B genes in inhabitants from the central area of Argentina

AIMS

The selection of the most appropriate treatment for several diseases relies on a number of factors such as environment, age, gender, and nutrition. Additionally, the contribution of different genetic polymorphisms to treatment efficacy has been largely recognized. The lack of information on the pharmacogenetic profile of our population prompted us to analyze the frequency of polymorphisms known to be relevant to achieve treatment efficacy with different therapeutic agents in viral infectious diseases, such as Hepatitis C and AIDS.

RESULTS

The allelic frequencies for the wild-type variant of the genes analyzed were cytochrome P450 2B6 (CYP2B6; rs3745274; 516G) 0.618 (95% confidence interval [CI]: 0.523, 0.711), chemokine coreceptor 5 (CCR5; rs333) 0.961 (95% CI: 0.942, 0.98), histocompatibility complex P5 (HCP5; rs2395029; 335T) 0.971 (95% CI: 0.937, 1), and interleukin 28B (IL28B; rs12979860; 12007005C) 0.656 (95% CI: 0.564, 0.747), respectively.

CONCLUSIONS

Our data indicate that the genetic profile of the population studied is similar to that reported for other Caucasian populations, with only slight differences for CYP2B6. Noteworthy, the considerable number of patients carrying CYP2B6 (516T) and IL28B (12007005T) alleles underlies the importance of considering pharmacogenetic testing before starting drug therapy protocols to prevent toxicity and/or lack of effectiveness in AIDS or hepatitis C virus infections.

Do human polyoma viruses and human immunodeficiency virus share common co-receptors?

Host and/or viral factors involved in human polyomavirus (HPoV) infection in persons living with HIV remain unknown. A hypothesis is outlined suggesting the importance of the co-receptors CCR5, CCR2, and CXCR4 not only for HIV, but also for HPoV. Functionally capable receptors coded by wild-type (wt) genotypes could facilitate internalization of HPoV in the cell resulting in brain and/or kidney infection/s in HIV infected individuals. Forty-nine Bulgarians with HIV, all treated by HAART, without neurological and/or kidney disorders, were tested for JCV and BKV and genotyped for CCR5 (CCR5del32), CCR2 (CCR2-64I), and CXCR4 (SDF1-3'A). In 27/49 (55.1%) individuals a co-infection with HPoV was identified-BKV in 12/49 (24.5%), JCV-in another 12/49 (24.5%), and both viruses-in 3/49 (6.1%). A high frequency of wt CCR5 was found in patients with HPoV (91.7% for BKV and JCV and in 100% with both viruses). V/V of CCR2 was presented in 75% for BKV and JCV and in 66.7% for BKV plus JCV. SDF1-3'G/G predominated in JCV infected patients (75%), while G/A and A/A genotypes were more frequent in patients with BKV (41.7%). Also, 21/22 (95.4%) persons without HPoV infection were heterozygous for SDF1 and CCR2. The number of individuals bearing wt of all co-receptors in the group of persons not infected with HPoV was lower (P = 0.03) than that with polymorphism/s in one or two genes (SDF1 and CCR2) in the same group. The results suggest a probable role of co-receptors used by HIV to facilitate infection with HPoV.

Distribution of CCR5-Delta32, CCR5m303A, CCR2-64I and SDF1-3'A in HIV-1 infected and uninfected high-risk Uighurs in Xinjiang, China

BACKGROUND

Genetic variants of the genes encoding HIV-1 co-receptors and their ligands, CCR5-Delta32, CCR5m303A, CCR2-64I and SDF1-3'A, are implicated in the susceptibility to HIV-1 infection, and the prevalence of these mutations varies by ethnicity. However, little is known about their distribution in Uighurs.

OBJECTIVES

This study aimed at characterizing the frequency of these HIV-related gene variants in a high-risk Uighur population.

STUDY DESIGNS

A total of 251 HIV-1 seropositive and 238 seronegative high-risk Uighurs were recruited and their genotypes of CCR5-Delta32, CCR5m303A, CCR2-64I and SDF1-3'A were analyzed by PCR and PCR-ligase detection reaction (PCR-LDR).

RESULTS

The allelic frequency of CCR5-Delta32, CCR5m303A, CCR2-64I and SDF1-3'A was 4.40%, 2.66%, 25.66% and 57.36%, respectively, in this population. Apparently, the Uighur population has low frequency of CCR5-Delta32 and CCR5m303A, but high frequency of CCR2-64I and SDF1-3'A. While there was no significant difference in the frequency of CCR5-Delta32, CCR2-64I and SDF1-3' A between HIV-1 seropositive and seronegative groups the frequency of CCR5m303A in HIV-1 seropositive group was significantly higher than that in seronegative group (P=0.006, OR=3.982 and 95%CI 1.514-10.476).

CONCLUSIONS

Our data suggest that the CCR5-Delta32, CCR2-64I and SDF1-3'A variants may have limited effect on protecting from HIV-1 infection in Uighurs. Rather, the CCR5m303A may be associated with the risk for HIV-1 infection in high-risk Uighurs.

Cerebrospinal fluid levels of chemokines in HIV infected patients with and without opportunistic infection of the central nervous system

Chemokines are chemoattractant cytokines involved in the immune response of a wide variety of diseases. There are few studies assessing their role in opportunistic infections in HIV-infected patients. In this study, we measured CC and CXC chemokines in cerebrospinal fluid (CSF) samples obtained from 40 HIV-infected patients with or without opportunistic infections of the central nervous system (CNS). CSF samples were also analyzed for quantification of total protein, cell count and HIV-1 RNA. HIV+ patients with cryptococcal meningitis had higher levels of CCL2, CCL3, CCL5, CXCL9 and CXCL10 when compared to patients without opportunistic neurological infections. Furthermore, HIV+ patients with associated cryptococcal meningitis had higher levels of CCL3, CXCL9 and CXCL10 when compared to HIV+ patients with associated toxoplasmic encephalitis. CCL3 and CXCL9 levels were positively correlated with CSF HIV-1 RNA levels, CSF protein concentration, and CSF cell count. CXCL10 level was correlated with the CSF viral load and the CSF cell count and CCL5 level was correlated with the CSF cell count. In conclusion, the profile of chemokines in CSF of HIV patients may differ according to the modality of the presented opportunistic infection and according to other biological markers, such as viral load in CSF. These differences are probably related to different patterns of neuroinflammatory responses displayed by patients with different opportunistic neurological infections.