Polimorfismo genético del correceptor CCR5 en pacientes cubanos VIH/sida de la tercera edad / Genetic polymorphism of the CCR5 coreceptor in Cuban elderly HIV/AIDS patients

Introducción: El polimorfismo en algunos genes de quimiocinas se asocia con resistencia a la infección por VIH-1, en este sentido la presencia de la mutación Δ32 del correceptor CCR5 en homocigosis, se relaciona con resistencia a la infección y la mutación heterocigótica con un retraso en la progresión de la enfermedad. Objetivos: Identificar la frecuencia del polimorfismo genético del correceptor CCR5 en los pacientes bajo estudio, así como su relación con los niveles de linfocitos T CD4+, la carga viral y las enfermedades oportunistas. Métodos: Se realizó un estudio de corte transversal en 45 pacientes VIH/sida de la tercera edad, cubanos atendidos en el Centro Hospitalario Universitario del IPK durante los meses de enero a mayo de 2019 en el servicio de Medicina del Centro Hospitalario Universitario del IPK, a los que se les realizó la reacción en cadena de la polimerasa (PCR) para determinar el polimorfismo genético del correceptor CCR5. Resultados: El polimorfismo genético del correceptor CCR5 que predominó fue el homocigótico salvaje con 87 por ciento seguido del heterocigótico Δ32 con 13 por ciento. El 80 por ciento de los pacientes presentaron carga viral no detectable y el 56 por ciento niveles de linfocitos T CD4+ por encima de 350 cél/µL. La enfermedad oportunista que predominó fue la neumonía por Pneumocystis jirovecii en 32 por ciento de los sujetos estudiados. No se observaron diferencias estadísticamente significativas entre el polimorfismo genético del correceptor CCR5 y los niveles de linfocitos T CD4+, la carga viral y las enfermedades oportunistas presentes en los pacientes estudiados. Conclusiones: Los polimorfismos genéticos del correceptor CCR5 hallados fueron el homocigótico salvaje y el heterocigótico-∆32. Fue limitado el polimorfismo del gen en los pacientes estudiados(AU)

Introduction: Polymorphism in some chemokine genes is associated to resistance to HIV-1 infection. Homozygous Δ32 mutation of the CCR5 coreceptor is related to resistance to infection, whereas heterozygous mutation is related to a delay in the progress of the disease. Objectives: Identify the frequency of genetic polymorphism of the CCR5 coreceptor in the patients studied, as well as its relationship to CD4+ T lymphocyte levels, viral load and opportunistic diseases. Methods: A cross-sectional study was conducted of 45 Cuban elderly HIV/AIDS patients attending the Medicine Service of the University Hospital Center at IPK from January to May 2019. These patients underwent polymerase chain reaction testing (PCR) to determine genetic polymorphism of the CCR5 coreceptor. Results: A predominance was found of wild homozygotous genetic polymorphism of the CCR5 coreceptor with 87 percent, followed by heterozygotous Δ32 genetic polymorphism with 13 percent. In 80 percent of the patients studied the viral load was undetectable, whereas in 56 percent CD4+ T lymphocyte levels were above 350 cel/µl. The prevailing opportunistic disease was Pneumocystis jirovecii pneumonia in 32 percent of the subjects. Statistically significant differences were not found between genetic polymorphism of the CCR5 coreceptor and CD4+ T lymphocyte levels, viral load and the opportunistic diseases present in the patients studied. Conclusions: The genetic polymorphisms of the CCR5 coreceptor found in the study were of the wild homozygotous and heterozygotous Δ32 types. Gene polymorphism was limited in the patients studied(AU)

Canonical and non-canonical Wnt signaling are simultaneously activated by Wnts in colon cancer cells.

The Wnt signaling pathway is a crucial regulator of the intestinal epithelium homeostasis and is altered in most colon cancers. While the role of aberrant canonical, ß-catenin-dependent Wnt signaling has been well established in colon cancer promotion, much less is known about the role played by noncanonical, ß-catenin-independent Wnt signaling in this type of cancer. This work aimed to characterize the noncanonical signal transduction pathway in colon cancer cells. To this end, we used the prototype noncanonical ligand, Wnt5a, in comparison with Wnt3a, the prototype of a canonical ß-catenin activating ligand. The analysis of the expression profile of Wnt receptors in colon cancer cell lines showed a clear increase in both level expression and variety of Frizzled receptor types expressed in colon cancer cells compared with non-malignant cells. We found that Wnt5a activates a typical Wnt/Ca++ - noncanonical signaling pathway in colon malignant cells, inducing the hyperphosphorylation of Dvl1, Dvl2 and Dvl3, promoting Ca++ mobilization as a result of phospholipase C (PLC) activation via pertussis toxin-sensitive G-protein, and inducing PLC-dependent cell migration. We also found that while the co-receptor Ror2 tyrosine kinase activity is not required for Ca++ mobilization-induced by Wnt5a, it is required for the inhibitory effects of Wnt5a on the ß-catenin-dependent transcriptional activity. Unexpectedly, we found that although the prototype canonical Wnt3a ligand was unique in stimulating the ß-catenin-dependent transcriptional activity, it also simultaneously activated PLC, promoted Ca++ mobilization, and induced Rho kinase and PLC-dependent cell migration. Our data indicate, therefore, that a Wnt ligand can activate at the same time the so-called Wnt canonical and noncanonical pathways inducing the formation of complex signaling networks to integrate both pathways in colon cancer cells.

Young adults HIV-1 infected by vertical transmission in southern Brazil - Clinical, demographic, and virological features.

Combination antiretroviral therapy promotes longer life expectancy, making it possible for perinatally HIV-infected patients to achieve adulthood. Past therapy was not always optimized, suggesting that virological and host features may also play a role in survival. The aim of this study is to describe characteristics of HIV disease progression associated with virological features in adolescents perinatally that were HIV infected. A case series was conducted including 81 patients that were in follow-up at Hospital de Clínicas/Universidade Federal do Paraná, Curitiba, Brazil. Venous blood was collected to conduct tropism and viral subtype assays. The median age was 19 years old (interquartile range 18-21), and a majority of patients were female (54.3%). Viral subtype was obtained for 66 (82%) patients, and subtypes B and C were found in 34% and 59%, respectively. Tropism assay was conducted in 55 (67%) patients: 71% were R5 and 29% X4. Distribution of viral tropism and subtype shows a significant association of subtype C with R5 tropism. Subtype C is more prevalent in southern Brazil and also in the population infected with HIV by vertical transmission. Both R5 tropism and subtype C are associated with slower progression to AIDS. The survival of these patients may be related to virological features present in a benign pattern of disease progression.

Pace of Coreceptor Tropism Switch in HIV-1-Infected Individuals after Recent Infection.

HIV-1 entry into target cells influences several aspects of HIV-1 pathogenesis, including viral tropism, HIV-1 transmission and disease progression, and response to entry inhibitors. The evolution from CCR5- to CXCR4-using strains in a given human host is still unpredictable. Here we analyzed timing and predictors for coreceptor evolution among recently HIV-1-infected individuals. Proviral DNA was longitudinally evaluated in 66 individuals using Geno2pheno[coreceptor] Demographics, viral load, CD4+ and CD8+ T cell counts, CCR5Δ32 polymorphisms, GB virus C (GBV-C) coinfection, and HLA profiles were also evaluated. Ultradeep sequencing was performed on initial samples from 11 selected individuals. A tropism switch from CCR5- to CXCR4-using strains was identified in 9/49 (18.4%) individuals. Only a low baseline false-positive rate (FPR) was found to be a significant tropism switch predictor. No minor CXCR4-using variants were identified in initial samples of 4 of 5 R5/non-R5 switchers. Logistic regression analysis showed that patients with an FPR of >40.6% at baseline presented a stable FPR over time whereas lower FPRs tend to progressively decay, leading to emergence of CXCR4-using strains, with a mean evolution time of 27.29 months (range, 8.90 to 64.62). An FPR threshold above 40.6% determined by logistic regression analysis may make it unnecessary to further determine tropism for prediction of disease progression related to emergence of X4 strains or use of CCR5 antagonists. The detection of variants with intermediate FPRs and progressive FPR decay over time not only strengthens the power of Geno2pheno in predicting HIV tropism but also indirectly confirms a continuous evolution from earlier R5 variants toward CXCR4-using strains.IMPORTANCE The introduction of CCR5 antagonists in the antiretroviral arsenal has sparked interest in coreceptors utilized by HIV-1. Despite concentrated efforts, viral and human host features predicting tropism switch are still poorly understood. Limited longitudinal data are available to assess the influence that these factors have on predicting tropism switch and disease progression. The present study describes longitudinal tropism evolution in a group of recently HIV-infected individuals to determine the prevalence and potential correlates of tropism switch. We demonstrated here that a low baseline FPR determined by the Geno2pheno[coreceptor] algorithm can predict tropism evolution from CCR5 to CXCR4 coreceptor use.

Silencing the odorant receptor co-receptor RproOrco affects the physiology and behavior of the Chagas disease vector Rhodnius prolixus.

Olfaction is one of the main sensory modalities that allow insects to interpret their environment. Several proteins, including odorant-binding proteins (OBPs) and odorant receptors (ORs), are involved in this process. Odorant receptors are ion channels formed by a binding unit OR and an odorant receptor co-receptor (Orco). The main goal of this study was to characterize the Orco gene of Rhodnius prolixus (RproOrco) and to infer its biological functions using gene silencing. The full-length RproOrco gene sequence was downloaded from VectorBase. This gene has 7 introns and is located in the genome SuperContig GL563069: 1,017,713-1,023,165. RproOrco encodes a protein of 473 amino acids, with predicted 7 transmembrane domains, and is highly expressed in the antennae during all R. prolixus developmental stages. The RNAi technique effectively silenced RproOrco, reducing the gene's expression by approximately 73%. Interestingly, the effect of gene silencing persisted for more than 100 days, indicating a prolonged effect of dsRNA that was maintained even after molting. The phenotypic effects of silencing involved the following: (1) loss of the ability to find a vertebrate host in a timely manner, (2) decreased ingested blood volume, (3) delayed and decreased molt rate, (4) increased mortality rate, and (5) decreased egg laying. Our data strongly suggest that dsOrco disrupts R. prolixus host-finding behavior, which is further reflected in the blood ingestion, molting, mortality, and egg laying data. This study clearly demonstrates that Orco is an excellent target for controlling triatomine populations. Thus, the data presented here open new possibilities for the control of vector-borne diseases.

Distribution of SDF1-3'A polymorphisms in three different ethnic groups from Brazil

A mutation described as a G-to-A transition has been reported in SDF-1 gene (SDF1-3'A), being prevalent in all ethnic groups, except in Africans. This mutation is associated with the onset of AIDS progression. Our aim was to identify the frequency of this allele in different groups from Brazil: Tiriyó and Waiampi Amerindian tribes (Asian ancestry); selected blood donors from Joinville (German descendents); and from Salvador (predominance of African and Portuguese mixture). SDF1-3'A was screened by PCR/RFLP with MspI enzyme. Our results showed a high allelic frequency in Tiriyó tribe (0.24) and Joinville population (0.21), and a frequency of 0.17 and 0.05 in the Salvador population and in the Waiampi tribe, respectively. There was no statistical difference among the allelic frequencies in the studied ethnic groups, except in the Waiampi. Due to the great genetic diversity among Brazilian population and the lack of studies on SDF1-3'A allele, our study of this allelic frequency in these different Brazilian ethnic groups could be important to identification of biomarker for therapeutic support in progression to AIDS and a molecular marker for analysis of evolutionary relationships among human populations.