Increased IL-8 levels in HIV-infected individuals who initiated ART with CD4+ T cell counts <350 cells/mm3 - A potential hallmark of chronic inflammation

The identification of inflammatory markers in HIV+ individuals on ART is fundamental since chronic ART-controlled HIV infection is linked to an increased inflammatory state. In this context, we assessed plasma levels of pro-inflammatory cytokines (IL-1β, IL-8, and IL-12p70) of HIV+ individuals who initiated ART after immunosuppression (CD4⁺ T cell counts <350 cells/mm³). HIV+ individuals were stratified according to two extreme phenotypes: Slow Progressors (SPs; individuals with at least 8 years of infection before ART initiation) and Rapid Progressors (RPs; individuals who needed to initiate ART within 1-4 years after infection). A control group was composed of HIV-uninfected individuals. We found increased IL-8 levels (median: 5.13 pg/mL; SPs and RPs together) in HIV-infected individuals on ART as compared to controls (median: 3.2 pg/mL; p = 0.04), although no association with the progression profile (slow or rapid progressors) or CD4⁺ T cell counts at sampling was observed. This result indicates that IL-8 is a general marker of chronic inflammation in HIV+ individuals on ART, independently of CD4⁺ T cell counts at the beginning of the treatment or of the potential progression profile of the patient. In this sense, IL-8 may be considered a possible target for novel therapies focused on reducing inflammation in chronic HIV infection.

High CXCL10/IP-10 levels are a hallmark in the clinical evolution of the HIV infection

The aim of this study was to investigate the modulation of plasma CXCL10, CCL20, CCL22, CCL2, CCL17 and CCL24 levels in HIV-positive patients grouped according to extreme phenotypes of progression to AIDS, and at different stages of HIV infection. HIV-positive individuals with extreme phenotypes of AIDS progression (n=58) at different clinical stages (chronic individuals, both pre-HAART and under-HAART) and HIV-negative controls (n=20) were evaluated. Additionally, HIV-positive individuals that initiated HAART with >350CD4⁺T-cells/mm³ were compared with those who initiated treatment with <350CD4⁺T-cells/mm³. Plasma levels of six chemokines were quantified by a Luminex assay. Higher CXCL10 levels were observed in individuals immediately before their CD4⁺T-cell levels were indicative for HAART (pre-HAART), independently of their progressor status, i.e. slow (SPs) or rapid progressors (RPs). SPs pre-HAART showed higher CXCL10 levels compared to elite controllers and RPs under HAART (p_c=0.009 and p_c=0.007, respectively). CXCL10 levels were higher in SPs HAART CD4<350 (initiated HAART with <350 CD4⁺T-cells) when compared with SPs HAART CD4>350 (initiated HAART with >350 CD4⁺T-cells) (1096 vs. 360.33pg/mL, p=0.0101). Normalisation of CXCL10 levels seems to depend on the CD4⁺T-cell nadir at HAART initiation. CCL20 levels were higher in chronic SPs, SPs pre-HAART, SPs HAART and RPs HAART compared with the HIV-negative controls, indicating persistent CCL20 expression. In conclusion, our results indicate that CXCL10 levels are a hallmark in the clinical evolution of HIV infection. However, our results must be verified in a study evaluating a larger number of AIDS progressors.

Association of NR1I2 gene polymorphisms and time of progression to AIDS

BACKGROUND

The time of progression towards AIDS can vary greatly among seropositive patients, and may be associated with host genetic variation. The NR1I2 (PXR) gene, a ligand-activated transcription factor, regulates the transcription immune pathway genes and can therefore be targets of viral replication mechanisms influencing time of progression to AIDS.

OBJECTIVE

To verify the association of single nucleotide polymorphisms (SNPs) rs3814057, rs6785049, rs7643645, and rs2461817 in the NR1I2 (PXR) gene with progression to AIDS in HIV-1 infected patients.

METHODS

Blood samples were obtained from 96 HIV-1 positive individuals following informed consent. DNA was isolated and genotyped through real time polymerase chain reaction (PCR) for the presence of SNPs in the NR1I2. Questionnaires on socio-demographic features and behaviors were answered and time of progression to AIDS was estimated based on medical chart analysis.

FINDINGS

Patients with the GG genotype for rs7643645 were shown to be related with a more rapid disease progression when compared to GA and AA genotypes. This result was maintained by the Multivariate Cox Regression considering sex, ethnicity, and presence of HLA-B*57, HLA-B*27, and CCR5del32 polymorphisms.

MAIN CONCLUSIONS

Recent studies reported the expression of the nuclear receptors in T-Lymphocytes, suggesting their possible role in the immune response. In addition, nuclear receptors have been shown to inhibit the HIV replication, although no such mechanism has been thoroughly elucidated to date. This is the first time an association between NR1I2 polymorphism and time of progression to AIDS is reported and supports an apparent relationship between the gene in the immune response and identifies another genetic factor influencing AIDS progression.

Endosomal toll-like receptor gene polymorphisms and susceptibility to HIV and HCV co-infection - Differential influence in individuals with distinct ethnic background

The genetic background of human populations can influence the susceptibility and outcome of infection diseases. Toll-like receptors (TLRs) have been previously associated with susceptibility to human immunodeficiency virus (HIV) infection, disease progression and hepatitis C, virus (HCV) co-infection in different populations, although mostly in Europeans. In this study, we investigated the genetic role of endosomal TLRs on susceptibility to HIV infection and HCV co-infection through the analysis of TLR7 rs179008, TLR8 rs3764880, TLR9 rs5743836 and TLR9 rs352140 polymorphisms in 789 Brazilian individuals (374 HIV+ and 415 HIV-), taking into account their ethnic background. Amongst the 357 HIV+ individuals with available data concerning HCV infection, 98 were positive. In European descendants, the TLR9 rs5743836 C carriers displayed a higher susceptibility to HIV infection [dominant, Odds Ratio (OR)=1.53; 95% CI: 1.05-2.23; P=0.027]. In African descendants, TLR9 rs5743836 CT genotype was associated with protection to HIV infection (codominant, OR=0.51; 95% CI: 0.30-0.87; P=0.013). Also, the TLR9 rs352140 AA variant genotype was associated with susceptibility to HIV+/HCV+ co-infection in African descendants (recessive, OR=2.92; 95% CI: 1.22-6.98, P=0.016). These results are discussed in the context of the different ethnic background of the studied individuals highlighting the influence of this genetic/ethnic background on the susceptibility to HIV infection and HIV/HCV co-infection in Brazilian individuals.

Role of SEP15 Gene Polymorphisms in the Time of Progression to AIDS

AIMS

HIV infection is a chronic disease that requires intensive treatment in its later phases, including dietary supplementation. Several studies have suggested clinical improvements in patients with high levels of selenium, linking these levels with a longer progression to AIDS. The objective of this study was to verify the association of two polymorphisms in the SEP15 gene, which encodes a selenoprotein that is responsible for the transport of selenium in cells, with the time of progression to AIDS in HIV-1-infected patients.

METHODS

Blood samples were obtained from 139 HIV-1-positive individuals after they provided informed consent. DNA was isolated and genotyped using real-time polymerase chain reaction for the presence of SEP15 single nucleotide polymorphisms (rs5859 and rs561104). Questionnaires on sociodemographic features and behavior were answered, and the time of progression to AIDS was estimated based on a medical chart analysis.

RESULTS

The allelic and genotypic frequencies did not differ between rapid and nonrapid progressors; however, the presence of the AA genotype of the rs5859 polymorphism was associated with a shorter time of progression to AIDS compared with GG homozygotes (hazard ratio = 3.62, 95% CI = 1.55-8.43, p = 0.003).

CONCLUSION

These findings show the importance of genetic analysis of the SEP15 gene in individual patients with regard to predicting time of progression to AIDS.

Association between cytokine gene polymorphisms and outcome of hepatitis B virus infection in southern Brazil

A number of studies have demonstrated associations between cytokine gene polymorphisms and outcome of hepatitis B virus (HBV) infection. However, no general consensus has been reached, possibly due to differences between ethnic groups. In this study, 345 individuals living in southern Brazil, including 196 chronic HBV carriers and 149 subjects who had spontaneously recovered from acute infection, were enrolled to evaluate the influence of cytokine gene polymorphisms on the outcome of HBV infection. Most participants were of European descent. Genotyping of IL2-330 G/T, IL4-589C/T, IL6-174 G/C, IL10-592C/A, IL10-1082 A/G, IL17A-197 G/A, IL17A-692 T/C, TNF-α-238 G/A, and TNF-α-308 G/A single nucleotide polymorphisms was performed by using the minisequencing (single base extension) method. By multivariable analysis, a statistically significant association was found between genotypic profile AA + GA in TNF-α-308 and chronic HBV infection (OR, 1.82; 95%CI, 1.01-3.27; P = 0.046). In southern Brazil, the carriers of the -308A allele in the TNF-α gene promoter have a moderately higher risk of becoming chronic carriers in case of HBV infection. In addition, patients with chronic active hepatitis B (n = 60) exhibited a decreased frequency (3.3%) of the TNF-238A allele when compared to that (14.8%) found among asymptomatic HBV carriers (n = 136), suggesting that this could be a protective factor against liver injury (OR, 0.17; 95%CI, 0.04-0.076; P = 0.023). J. Med. Virol. 88:1759-1766, 2016. © 2016 Wiley Periodicals, Inc.

Detection of the B"-GWGR variant in the southernmost region of Brazil: unveiling the complexity of the human immunodeficiency virus-1 subtype B epidemic

Typical human immunodeficiency virus-1 subtype B (HIV-1B) sequences present a GPGR signature at the tip of the variable region 3 (V3) loop; however, unusual motifs harbouring a GWGR signature have also been isolated. Although epidemiological studies have detected this variant in approximately 17-50% of the total infections in Brazil, the prevalence of B"-GWGR in the southernmost region of Brazil is not yet clear. This study aimed to investigate the C2-V3 molecular diversity of the HIV-1B epidemic in southernmost Brazil. HIV-1 seropositive patients were ana-lysed at two distinct time points in the state of Rio Grande do Sul (RS98 and RS08) and at one time point in the state of Santa Catarina (SC08). Phylogenetic analysis classified 46 individuals in the RS98 group as HIV-1B and their molecular signatures were as follows: 26% B"-GWGR, 54% B-GPGR and 20% other motifs. In the RS08 group, HIV-1B was present in 32 samples: 22% B"-GWGR, 59% B-GPGR and 19% other motifs. In the SC08 group, 32 HIV-1B samples were found: 28% B"-GWGR, 59% B-GPGR and 13% other motifs. No association could be established between the HIV-1B V3 signatures and exposure categories in the HIV-1B epidemic in RS. However, B-GPGR seemed to be related to heterosexual individuals in the SC08 group. Our results suggest that the established B"-GWGR epidemics in both cities have similar patterns, which is likely due to their geographical proximity and cultural relationship.

Co-circulation HIV-1 subtypes B, C, and CRF31_BC in a drug-naïve population from Southernmost Brazil: analysis of primary resistance mutations

In Southernmost Brazil HIV-1 subtypes B, C, and CRF31_BC co-circulates and, since 1996 with the implementation of free access to highly active antiretroviral treatment (HAART), this epidemic is under a quite characteristic selective pressure. The profile of mutations and polymorphisms in the protease (PR) and reverse transcriptase (RT) genes of HIV-1 from untreated patients living in Porto Alegre, Southernmost Brazil were evaluated in order to identify the subtypes and circulating drug resistant genotypes. Blood samples from 99 HIV-1 positive drugs-naïve patients were collected from 2006 to 2007 in Porto Alegre, Brazil. HIV PR and RT genes were amplified, sequenced, and subtyped. The HIV-1 genotyping was performed by partial sequence analysis of the pol in the HIV Drug Resistance Database of Stanford University. Phylogenetic analyses allowed to classify the HIV samples according to their subtypes: B (26.2%), C (39.4%), F (1.1%), CRF31_CB (19.2%), and URF (14.1%). Eight (8.1%) samples showed primary resistance mutations according to the Calibrated Population Resistance tool based in the 2009 Surveillance Drug Resistance Mutation list. Two samples presented resistance mutations to PI, three NRTI and three NNRTI. There was no significant association between presence of resistant genotypes and subtypes, but resistance mutations seem to be less frequent in the subtype C. In addition, this study describes for the first time the mutational profile of CRF31_BC to PI, NRTI, and NNRTI. Genetic analyses of HIV-1 from naïve patients are a promising and important method for surveillance of HIV infection.

Reviewing the history of HIV-1: spread of subtype B in the Americas

The dispersal of HIV-1 subtype B (HIV-1B) is a reflection of the movement of human populations in response to social, political, and geographical issues. The initial dissemination of HIV-1B outside Africa seems to have included the passive involvement of human populations from the Caribbean in spreading the virus to the United States. However, the exact pathways taken during the establishment of the pandemic in the Americas remain unclear. Here, we propose a geographical scenario for the dissemination of HIV-1B in the Americas, based on phylogenetic and genetic statistical analyses of 313 available sequences of the pol gene from 27 countries. Maximum likelihood and Bayesian inference methods were used to explore the phylogenetic relationships between HIV-1B sequences, and molecular variance estimates were analyzed to infer the genetic structure of the viral population. We found that the initial dissemination and subsequent spread of subtype B in the Americas occurred via a single introduction event in the Caribbean around 1964 (1950–1967). Phylogenetic trees present evidence of several primary outbreaks in countries in South America, directly seeded by the Caribbean epidemic. Cuba is an exception insofar as its epidemic seems to have been introduced from South America. One clade comprising isolates from different countries emerged in the most-derived branches, reflecting the intense circulation of the virus throughout the American continents. Statistical analysis supports the genetic compartmentalization of the virus among the Americas, with a close relationship between the South American and Caribbean epidemics. These findings reflect the complex establishment of the HIV-1B pandemic and contribute to our understanding between the migration process of human populations and virus diffusion.

Evaluation of a novel microplate colorimetric hybridization genotyping assay for human papillomavirus

Persistent infection with high-risk human papillomavirus (HR-HPV) has been associated with cervical cancer. Developing assays for the identification of these viral types is of great importance for monitoring patients and controlling strategies. The development of the MCHA (microplate colorimetric hybridization assay), a PCR-based method for identifying six of the most common HR-HPV types (HPV 16, 18, 31, 33, 39 and 45) is described. The MCHA combines the amplification with the GP5+/GP6+ consensus primers followed by PCR reverse hybridization with specific probes and detection through a colorimetric assay. The performance of the MCHA was evaluated using 108 DNA samples typed previously by the PapilloCheck(®). The agreement between both methods was 69.4% for HPV 16; 79.1% for HPV 45; 82.4% for HPV 18; 93.6% for HPV 31; 87.9% for HPV 33, and 17.6% for HPV 39. The assay had higher sensitivity than the Papillocheck(®), particularly for identifying HPV 16 and 18. The MCHA seemed to be sensitive and specific for the identification of the most prevalent HPV types in invasive cervical cancer, HPV 16, 18, 45, 33 and 31. It requires low-cost reagents and common laboratory apparatus.