Asymmetric HIV-1 co-receptor use and replication in CD4+ T lymphocytes

Susceptibility to infection by the human immunodeficiency virus type-1 (HIV-1), both in vitro and in vivo, requires the interaction between its envelope (Env) glycoprotein gp120 Env and the primary receptor (R), CD4, and Co-R, either CCR5 or CXCR4, members of the chemokine receptor family. CCR5-dependent (R5) viruses are responsible for both inter-individual transmission and for sustaining the viral pandemics, while CXCR4-using viruses, usually dualtropic R5X4, emerge in ca. 50% of individuals only in the late, immunologically suppressed stage of disease. The hypothesis that such a major biological asymmetry is explained exclusively by the availability of cells expressing CCR5 or CXCR4 is challenged by several evidences. In this regard, binding of the HIV-1 gp120 Env to the entry R complex, i.e. CD4 and a chemokine R, leads to two major events: virion-cell membrane fusion and a cascade of cell signaling. While the fusion/entry process has been well defined, the role of R/Co-R signaling in the HIV-1 life cycle has been less characterized. Indeed, depending on the cellular model studied, the capacity of HIV-1 to trigger a flow of events favoring either its own latency or replication remains a debated issue. In this article, we will review the major findings related to the role of HIV R/Co-R signaling in the steps following viral entry and leading to viral spreading in CD4+ T lymphocytes

Mixed Adenocarcinoma of the Rectovaginal Septum Associated with Endometriosis and Endometrial Carcinoma: A Case Report

Purpose: To present a case of primary mixed (clear cell and endometrioid type) adenocarcinoma of the rectovaginal septum, probably arising from endometriosis and associated with a highly differentiated, early-stage endometrioid endometrial carcinoma. The case was managed by a minimally invasive approach and postoperative adjuvant chemotherapy. Results: The patient underwent clinical/instrumental follow-up and a second-look laparoscopy after the primary surgery as well as adjuvant chemotherapy. No evidence of disease could be observed after the treatment. Conclusion: Surgery with postoperative chemotherapy can be recommended for the treatment of mixed adenocarcinoma of the rectovaginal septum

Coronaviridae and SARS-associated Coronavirus Strain HSR1

During the recent severe acute respiratory (SARS) outbreak, the etiologic agent was identified as a new coronavirus (CoV). We have isolated a SARS-associated CoV (SARS-CoV) strain by injecting Vero cells with a sputum specimen from an Italian patient affected by a severe pneumonia; the patient traveled from Vietnam to Italy in March 2003. Ultrastructural analysis of infected Vero cells showed the virions within cell vesicles and around the cell membrane. The full-length viral genome sequence was similar to those derived from the Hong-Kong Hotel M isolate. By using both real-time reverse transcription–polymerase chain reaction TaqMan assay and an infectivity plaque assay, we determined that approximately 360 viral genomes were required to generate a PFU. In addition, heparin (100 μg/mL) inhibited infection of Vero cells by 50%. Overall, the molecular and biologic characteristics of the strain HSR1 provide evidence that SARS-CoV forms a fourth genetic coronavirus group with distinct genomic and biologic features

HIV-1 transcriptional silencing caused by TRIM22 inhibition of Sp1 binding to the viral promoter

Background: Intracellular defense proteins, also referred to as restriction factors, are capable of interfering with different steps of the viral life cycle. Among these, we have shown that Tripartite motif 22 (TRIM22) suppresses basal as well as phorbol ester-induced HIV-1 long terminal repeat (LTR)-mediated transcription, independently of its E3 ubiquitin ligase activity, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) binding to the U3 region and Tat interaction with the TAR region of the HIV-1 LTR. As basal HIV-1 transcription is driven by the transcription factor specificity protein 1 (Sp1), we have investigated whether TRIM22 could interfere with Sp1-driven transcriptional activation of the HIV-1 LTR. Findings: 293T cells, devoid of endogenous TRIM22 expression, were transfected with a TRIM22-expressing plasmid together with reporter plasmids driven by the HIV-1 LTR promoter either containing or lacking Sp1 binding sites or with reporter plasmids driven by non-viral promoter sequences either containing or lacking the three Sp1 binding sites from the HIV-1 LTR. These reporter assays showed that TRIM22 efficiently inhibited Sp1-driven transcription. Knocking down TRIM22 expression in the CD4+ SupT1 T cell line increased the replication of Sp1-dependent HIV-1 variants. TRIM22 did not interact with Sp1, but prevented binding of Sp1 to the HIV-1 promoter, as demonstrated in protein-DNA pull down and chromatin immunoprecipitation assays. Conclusion: TRIM22 acts as a suppressor of basal HIV-1 LTR-driven transcription by preventing Sp1 binding to the HIV-1 promoter

Heterogeneity of Signal Transducer and Activator of Transcription Binding Sites in the Long-Terminal Repeats of Distinct HIV-1 Subtypes

HIV-1 can be subdivided into distinct subtypes; the consequences of such a genomic variability remain largely speculative. The long terminal repeats (LTR) control HIV transcription and reflect the major differences of distinct viral subtypes. Three regions in the HIV-1 subtype B LTR are close matches to the Signal Transducer and Activator of Transcription (STAT) consensus sequence. Here, we show heterogeneity in these putative STAT binding sites among HIV-1 LTR subtypes A through G. Transfection of constitutively activated STAT5 lead to transcriptional activation of HIV-1 expression in 293T cells transfected with a reporter assay driven by HIV-1 LTR subtype B. Constitutively activated STAT5 transactivated the LTR of various subtypes in U937 cells with different potency. These findings support and expand the potential relevance of STAT5 activation in HIV infection and may bear relevance for a differential regulation of latency and expression of different subtypes of HIV-1

Generation of potent neutralizing human monoclonal antibodies against cytomegalovirus infection from immune B cells

<p>Abstract</p> <p>Background</p> <p>Human monoclonal antibodies (mAbs) generated as a result of the immune response are likely to be the most effective therapeutic antibodies, particularly in the case of infectious diseases against which the immune response is protective.</p> <p>Human cytomegalovirus (HCMV) is an ubiquitous opportunistic virus that is the most serious pathogenic agent in transplant patients. The available therapeutic armamentarium (e.g. HCMV hyperimmune globulins or antivirals) is associated with severe side effects and the emergence of drug-resistant strains; therefore, neutralizing human mAb may be a decisive alternative in the prevention of primary and re-activated HCMV infections in these patients.</p> <p>Results</p> <p>The purpose of this study was to generate neutralizing mAb against HCMV from the immunological repertoire of immune donors. To this aim, we designed an efficient technology relying on two discrete and sequential steps: first, human B-lymphocytes are stimulated with TLR9-agonists and IL-2; second, after both additives are removed, the cells are infected with EBV. Using this strategy we obtained 29 clones secreting IgG neutralizing the HCMV infectivity; four among these were further characterized. All of the mAbs neutralize the infection in different combinations of HCMV strains and target cells, with a potency ~20 fold higher than that of the HCMV hyperimmune globulins, currently used in transplant recipients. Recombinant human monoclonal IgG1 suitable as a prophylactic or therapeutic tool in clinical applications has been generated.</p> <p>Conclusion</p> <p>The technology described has proven to be more reproducible, efficient and rapid than previously reported techniques, and can be adopted at low overall costs by any cell biology laboratory for the development of fully human mAbs for immunotherapeutic uses.</p

Case report: Sodium-glucose cotransporter 2 inhibitors induce left ventricular reverse remodeling in anthracycline-related cardiac dysfunction—a case series

PurposeTo describe the efficacy and safety of sodium-glucose cotransporter 2 inhibitors as a specific treatment for anthracycline-related cardiac dysfunction in a small real-world population.MethodsSeven patients with anthracycline-related cardiac dysfunction were clinically and echocardiographically evaluated before and after the introduction of sodium-glucose cotransporter 2 inhibitors.ResultsAfter a median period of 24 weeks with uninterrupted sodium-glucose cotransporter 2 inhibitors treatment, a significant clinical improvement was observed with at least one New York Heart Association Functional Class (NHYA FC) improvement in all patients (median NYHA FC: I vs. III, p &lt; 0.010). A noteworthy left ventricular reserve remodeling (median left ventricular end diastolic volume indexed: 53 vs. 82.5 ml/m2, p = 0.018; median left ventricular ejection fraction: 50% vs. 40%, p = 0.17) was also observed. Sodium-glucose cotransporter 2 inhibitors therapy was well tolerated by every patients; no cases of discontinuation or relevant side effects were observed.ConclusionSodium-glucose cotransporter 2 inhibitors induce a significant clinical improvement and left ventricular reserve remodeling in patients affected by anthracycline-related cardiac dysfunction