STAT3 mutation impacts biological and clinical features of T-LGL leukemia

STAT3 mutations have been described in 30-40% of T-large granular lymphocyte (T-LGL) leukemia patients, leading to STAT3 pathway activation. Considering the heterogeneity of the disease and the several immunophenotypes that LGL clone may express, the aim of this work was to evaluate whether STAT3 mutations might be associated with a distinctive LGL immunophenotype and/or might be indicative for specific clinical features.Our series of cases included a pilot cohort of 101 T-LGL leukemia patients (68 CD8+/CD4- and 33 CD4+/CD8\ub1) from Padua Hematology Unit (Italy) and a validation cohort of additional 20 patients from Rennes Hematology Unit (France).Our results indicate that i) CD8+ T-LGL leukemia patients with CD16+/CD56- immunophenotype identify a subset of patients characterized by the presence of STAT3 mutations and neutropenia, ii) CD4+/CD8\ub1 T-LGL leukemia are devoid of STAT3 mutations but characterized by STAT5b mutations, and iii) a correlation exists between STAT3 activation and presence of Fas ligand, this molecule resulting highly expressed in CD8+/CD16+/CD56- patients. Experiments with stimulation and inhibition of STAT3 phosphorylation confirmed this relationship. In conclusion, our data show that T-LGL leukemia with specific molecular and phenotypic patterns is associated with discrete clinical features contributing to get insights into molecular bases accounting for the development of Fas ligand-mediated neutropenia

Virological response and resistance profile in highly treatment-experienced HIV-1-infected patients switching to dolutegravir plus boosted darunavir in clinical practice

Objectives: We evaluated the virological response and resistance profile in combined antiretroviral therapy (cART)-experienced HIV-1-infected patients starting a dual therapy with dolutegravir (DTG) and boosted darunavir (bDRV) for the first time. Methods: Survival analyses were used to evaluate virological success (VS) and virological rebound (VR) in viraemic and virologically suppressed patients, respectively. Major resistance mutations (MRMs) and genotypic susceptibility score (GSS) were evaluated at baseline and after switch. Results: Overall, 130 patients [62 (47.7%) viraemic; 68 (52.3%) virologically suppressed] were retrospectively analysed. At the moment of switch, 81.5% accumulated one or more MRM [protease inhibitor (PI), 35.7%; nucleoside(t)ide reverse transcriptase inhibitor (NRTI), 77.5%; non-NRTI, 69.0%; integrase inhibitor (INI), 10.1%), but 77.7% harboured strains fully susceptible to DTG + bDRV. In viraemic patients, the overall probability of VS by 12 months of treatment was 91.7%. In virologically suppressed patients, the overall probability of VR was 10.5% by 24 months after therapy start. Patients with previous time under virological suppression ≤ 6 months showed a higher VR probability compared with others (37.5% vs. 6.7%, P < 0.002). Among 13 non-responding patients for whom a genotypic resistance test result at failure was available, only two (15.4%) accumulated further resistance in integrase (Y143C/H/R; S147G and N155H) and protease (V32I, L33F, I54L). Conclusions: In highly treatment-experienced patients, the use of dual therapy based on DTG + bDRV appears to be a very good regimen for switch therapy, with a high rate of virological control in both viraemic and virologically suppressed patients. Among non-responding patients, the selection of further resistance is a rare event

Analysis of HIV quasispecies and virological outcome of an HIV D+/R+ kidney-liver transplantation

Introduction Transplantation among HIV positive patients may be a valuable therapeutic intervention. This study involves an HIV D+/R+ kidney-liver transplantation, where PBMC-associated HIV quasispecies were analyzed in donor and transplant recipients (TR) prior to transplantation and thereafter, together with standard viral monitoring. Methods The donor was a 54 year of age HIV infected woman: kidney and liver recipients were two HIV infected men, aged 49 and 61. HIV quasispecies in PBMC was analyzed by ultra-deep sequencing of V3 env region. During TR follow-up, plasma HIV-1 RNA, HIV-1 DNA in PBMC, analysis of proviral integration sites and drug-resistance genotyping were performed. Other virological and immunological monitoring included CMV and EBV DNA quantification in blood and CD4 T cell counts. Results Donor and TR were all ART-HIV suppressed at transplantation. Thereafter, TR maintained a nearly suppressed HIV-1 viremia, but HIV-1 RNA blips and the increase of proviral integration sites in PBMC attested some residual HIV replication. A transient peak in HIV-1 DNA occurred in the liver recipient. No major changes of drug-resistance genotype were detected after transplantation. CMV and EBV transient reactivations were observed only in the kidney recipient, but did not require specific treatment. CD4 counts remained stable. No intermixed quasispecies between donor and TR was observed at transplantation or thereafter. Despite signs of viral evolution in TR, HIV genetic heterogeneity did not increase over the course of the months of follow up. Conclusions No evidence of HIV superinfection was observed in the donor nor in the recipients. The immunosuppressive treatment administrated to TR did not result in clinical relevant viral reactivations

Genetic divergence of HIV-1 B subtype in Italy over the years 2003\u20132016 and impact on CTL escape prevalence

HIV-1 is characterized by high genetic variability, with implications for spread, and immune-escape selection. Here, the genetic modification of HIV-1 B subtype over time was evaluated on 3,328 pol and 1,152 V3 sequences belonging to B subtype and collected from individuals diagnosed in Italy between 2003 and 2016. Sequences were analyzed for genetic-distance from consensus-B (Tajima-Nei), non-synonymous and synonymous rates (dN and dS), CTL escapes, and intra-host evolution over four time-spans (2003\u20132006, 2007\u20132009, 2010\u20132012, 2013\u20132016). Genetic-distance increased over time for both pol and V3 sequences (P < 0.0001 and 0.0003). Similar results were obtained for dN and dS. Entropy-value significantly increased at 16 pol and two V3 amino acid positions. Seven of them were CTL escape positions (protease: 71; reverse-transcriptase: 35, 162, 177, 202, 207, 211). Sequences with 653 CTL escapes increased from 36.1% in 2003\u20132006 to 54.0% in 2013\u20132016 (P < 0.0001), and showed better intra-host adaptation than those containing 642 CTL escapes (intra-host evolution: 3.0 7 10 123 [2.9 7 10 123\u20133.1 7 10 123] vs. 4.3 7 10 123 [4.0 7 10 123\u20135.0 7 10 123], P[LRT] < 0.0001[21.09]). These data provide evidence of still ongoing modifications, involving CTL escape mutations, in circulating HIV-1 B subtype in Italy. These modifications might affect the process of HIV-1 adaptation to the host, as suggested by the slow intra-host evolution characterizing viruses with a high number of CTL escapes

Interferon-α Improves Phosphoantigen-Induced Vγ9Vδ2 T-Cells Interferon-γ Production during Chronic HCV Infection

In chronic HCV infection, treatment failure and defective host immune response highly demand improved therapy strategies. Vγ9Vδ2 T-cells may inhibit HCV replication in vitro through IFN-γ release after Phosphoantigen (PhAg) stimulation. The aim of our work was to analyze Vγ9Vδ2 T-cell functionality during chronic HCV infection, studying the role of IFN-α on their function capability. IFN-γ production by Vγ9Vδ2 T-cells was analyzed in vitro in 24 HCV-infected patients and 35 healthy donors (HD) after PhAg stimulation with or without IFN-α. The effect of in vivo PhAg/IFN-α administration on plasma IFN-γ levels was analyzed in M. fascicularis monkeys. A quantitative analysis of IFN-γ mRNA level and stability in Vγ9Vδ2 T-cells was also evaluated. During chronic HCV infection, Vγ9Vδ2 T-cells showed an effector/activated phenotype and were significantly impaired in IFN-γ production. Interestingly, IFN-α was able to improve their IFN-γ response to PhAg both in vitro in HD and HCV-infected patients, and in vivo in Macaca fascicularis primates. Finally, IFN-α increased IFN-γ-mRNA transcription and stability in PhAg-activated Vγ9Vδ2 T-cells. Altogether our results show a functional impairment of Vγ9Vδ2 T-cells during chronic HCV infection that can be partially restored by using IFN-α. A study aimed to evaluate the antiviral impact of PhAg/IFN-α combination may provide new insight in designing possible combined strategies to improve HCV infection treatment outcome

SARS-CoV-2 Variants Identification: Overview of Molecular Existing Methods

Since the beginning of COVID-19 pandemic the Real Time sharing of genome sequences of circulating virus supported the diagnostics and surveillance of SARS-CoV-2 and its transmission dynamics. SARS-CoV-2 straightaway showed its tendency to mutate and adapt to the host, culminating in the emergence of variants; so it immediately became of crucial importance to be able to detect them quickly but also to be able to monitor in depth the changes on the whole genome to early identify the new possibly emerging variants. In this scenario, this manuscript aims to provide an overview of the existing methods for the identification of SARS-CoV-2 variants (from rapid method based on identification of one or more specific mutations to Whole Genome sequencing approach-WGS), taking into account limitations, advantages and applications of them in the field of diagnosis and surveillance of SARS-CoV-2

Potential implications of CYP3A4, CYP3A5 and MDR-1 genetic variants on the efficacy of Lopinavir/Ritonavir (LPV/r) monotherapy in HIV-1 patients

Several genetic single nucleotide polymorphisms (SNPs) in biotransformation enzymes (CYP3A4, CYP3A5) or transporter proteins (multidrug resistance MDR1 gene product, P-gp) are involved in PI metabolism so that PI pharmacokinetics is characterized by a large inter-individual variability. The aim of this study was: (i) to develop an in-house PCR/direct sequencing, based on DNA purification of full-length CYP3A4 and CYP3A5 genes (SNPs) and MDR1 C3435T variant; (ii) to investigate association of CYP3A4 and CYP3A5 reported or unreported genetic polymorphisms and MDR1-C3435T (CC homozygote, CT heterozygote, TT homozygote) with clinical outcome of HIV-1 infected subjects treated with PI.Methods: Overall, 39 HIV-1 infected patients receiving boosted Lopinavir (LPV/r) monotherapy after virological suppression were genotyped and analyzed through PCR and direct sequencing of full-length CYP3A4 and CYP3A5 gene sequences [1] and MDR1 gene (C3435T). CD4T-cell counts and plasma viral load were analyzed before and after LPV/r initiation; LPV/r therapeutic drug monitoring (TDM) was determined at 12-hours. Results: LPV/r TDM (ng/ml) did not show significant differences among CYP3A4 or CYP3A5 SNPs, although a mean lower level of LPV/r was associated with detection of several SNPs: CYP3A5*3 rs776746; CYP3A5 rs28365088, CYP3A5 rs15524, CYP3A4 rs2687116, and a not already described polymorphism CYP3A4 nt20338. In follow-up analysis, B90% adherence was the main factor associated with virological failure of LPV/r monotherapy (83.3% of failure vs 34.4%, pB0.001 at log-rank test). Adjusting for adherence, the detection of a single CYP3A5*3 rs776746 and CYP3A5 rs15524 SNPs was associated with higher probability of LPV/r monotherapy failure (pB0.01), and in general, detection of any CYP3A5 SNP was associated with failure (26.2% vs 58.3%, p0.067). No-association with detection of any CYP3A4 SNPs was found. MDR1 TT variants showed significant lower frequency of treatment failure (0.0% vs 47.7%, p0.026), since non-TT homozygote patient failed LPV/r monotherapy. Conclusions: Efficacy of PI monotherapy is strongly dependent from patient adherence, but, in adherent patients, genetic factors, such as CYP3A5 and MDR1-C3435T gene variants, may affect the response to treatment, though their role, as well of other genetic variants, need further investigation

Identification of a STAT3-miRNA Axis in T-LGL Leukemia

Introduction T large granular lymphocytes leukemia (T-LGLL) is a rare disease characterized by the abnormal expansion of T-large granular lymphocytes (T-LGLs) in the peripheral blood. The etiology of this disease is still largely unknown. LGL proliferation is maintained through an impairment of the apoptotic machinery due to the activation of many survival signals. Among these, JAK/STAT signaling represents one of the most important deregulated pathways in T-LGLL. In particular, leukemic LGLs are equipped with STAT3 constitutively over-expressed and over-activated. Moreover, in 30-40% of patients, STAT3 has been demonstrated carrying hot-spot mutations, likely resulting in STAT3 activation. Although STAT3 is an inducer of transcription of a large number of oncogenes, its relationship with microRNAs (miRNAs) has not yet been extensively evaluated in T-LGLL patients. As a matter of fact, several miRNAs contribute to normal hematopoietic processes and many miRNAs act both as tumor suppressors and oncogenes in the pathology of hematological malignancies, including acute and chronic leukemias and lymphomas, where they contribute to lymphomagenesis acting in various cellular functions, such as the regulation of cell survival and proliferation. Aims We investigated whether STAT3 could carry out its pathogenetic role in T-LGLL through an altered expression of miRNAs. A high throughput quantitative and qualitative analysis of the miRNA expression profile in leukemic LGLs compared to healthy controls was performed with the aim to investigate whether STAT3 activation and/or mutation were correlated to some miRNAs in leukemic LGLs. Methods Six patients (3 characterized by STAT3 mutations and 3 with wild type STAT3) and three healthy controls were enrolled in a pilot study. STAT3 mRNA expression and protein activation levels were analyzed by Real Time-PCR and Western Blot, respectively. The expression level of 756 mature miRNAs was assessed by using a TaqMan-based Low Density Array on purified LGLs. Experimental data were analyzed by ViiA7 RUO software and the relative miRNA expression values were calculated using U6 as endogenous control. miRNA array data underwent hierarchical cluster analysis (HCL) by using MEV. miRNAs with a 2 or 0.5 fold change and p value < 0.05 in samples as compared to controls were considered as differentially expressed. Results of this pilot study were validated on additional 12 T-LGLL and 3 healthy controls subjects. Results Two clusters were identified by HCL analysis: cluster A included healthy controls and LGL patients characterized by comparably low levels of STAT3 activation (S3low) and absence of STAT3 mutations. Cluster B included four patients characterized by high levels of STAT3 activation (S3high). Remarkably, three out of four LGL patients in cluster B shared STAT3 mutation. Comparative analysis of the miRNAs expressed identified 33 miRNAs upregulated and 9 miRNAs downregulated in S3high as compared to S3low. Interestingly, the level of expression of these selected miRNAs correlated with the level of STAT3 expression/activation in LGL. Among these, three miRNAs, miR-484, miR-501 and miR-1249, have been validated and confirmed in the validation cohort. Conclusions These data firstly describe the miRNA pattern in T-LGLL, providing evidence that a series of miRNAs are correlated with relevant key factors in T-LGLL pathogenesis, including STAT3 activation/expression and mutations. Our results suggest the hypothesis that STAT3 could mediate its role through some defined miRNAs