53 research outputs found

    Impaired respiratory function reduces haemoglobin oxygen affinity in COVID-19

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    SARS-CoV-2 Spike 1 Protein Controls Natural Killer Cell Activation via the HLA-E/NKG2A Pathway

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    Natural killer cells are important in the control of viral infections. However, the role of NK cells during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has previously not been identified. Peripheral blood NK cells from SARS-CoV and SARS-CoV-2 naïve subjects were evaluated for their activation, degranulation, and interferon-gamma expression in the presence of SARS-CoV and SARS-CoV-2 spike proteins. K562 and lung epithelial cells were transfected with spike proteins and co-cultured with NK cells. The analysis was performed by flow cytometry and immune fluorescence. SARS-CoV and SARS-CoV-2 spike proteins did not alter NK cell activation in a K562 in vitro model. On the contrary, SARS-CoV-2 spike 1 protein (SP1) intracellular expression by lung epithelial cells resulted in NK cell-reduced degranulation. Further experiments revealed a concomitant induction of HLA-E expression on the surface of lung epithelial cells and the recognition of an SP1-derived HLA-E-binding peptide. Simultaneously, there was increased modulation of the inhibitory receptor NKG2A/CD94 on NK cells when SP1 was expressed in lung epithelial cells. We ruled out the GATA3 transcription factor as being responsible for HLA-E increased levels and HLA-E/NKG2A interaction as implicated in NK cell exhaustion. We show for the first time that NK cells are affected by SP1 expression in lung epithelial cells via HLA-E/NKG2A interaction. The resulting NK cells’ exhaustion might contribute to immunopathogenesis in SARS-CoV-2 infection

    The U94 gene of human herpesvirus 6: a narrative review of its role and potential functions

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    Human herpesvirus 6 (HHV-6) is a β-herpesvirus that is highly prevalent in the human population. HHV-6 comprises two recognized species (HHV-6A and HHV-6B). Despite different cell tropism and disease association, HHV-6A/B show high genome homology and harbor the conserved U94 gene, which is limited to HHV-6 and absent in all the other human herpesviruses. U94 has key functions in the virus life cycle and associated diseases, having demonstrated or putative roles in virus replication, integration, and reactivation. During natural infection, U94 elicits an immune response, and the prevalence and extent of the anti-U94 response are associated with specific diseases. Notably, U94 can entirely reproduce some virus effects at the cell level, including inhibition of cell migration, induction of cytokines and HLA-G expression, and angiogenesis inhibition, supporting a direct U94 role in the development of HHV-6-associated diseases. Moreover, specific U94 properties, such as the ability to modulate angiogenesis pathways, have been exploited to counteract cancer development. Here, we review the information available on this key HHV-6 gene, highlighting its potential uses

    HHV-6A infection induces amyloid-beta expression and activation of microglial cells.

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    BACKGROUND: The control of viral infections in the brain involves the activation of microglial cells, the macrophages of the brain that are constantly surveying the central nervous system, and the production of amyloid-beta (Aβ) as an anti-microbial molecule. Recent findings suggest a possible implication of HHV-6A in AD. We evaluated the effect of HHV-6A infection on microglial cell expression Aβ and the activation status, determined by TREM2, ApoE, cytokines, and tau expression. METHODS: We have infected microglial cells (HMC3, ATCC®CRL-3304), in monolayer and human peripheral blood monocyte-derived microglia (PBM-microglia) spheroid 3D model, with HHV-6A (strain U1102) cell-free virus inocula with 100 genome equivalents per 1 cell. We collected the cells 1, 3, 7, and 14 days post-infection (d.p.i.) and analyzed them for viral DNA and RNA, ApoE, Aβ (1-40, 1-42), tau, and phospho-tau (Threonine 181) by real-time immunofluorescence and cytokines by immunoenzymatic assay. RESULTS: We observed a productive infection by HHV-6A. The expression of Aβ 1-42 increased from 3 d.p.i., while no significant induction was observed for Aβ 1-40. The HHV-6A infection induced the activation (TREM2, IL-1beta, ApoE) and migration of microglial cells. The secretion of tau started from 7 d.p.i., with an increasing percentage of the phosphorylated form. CONCLUSIONS: In conclusion, microglial cells are permissive to HHV-6A infection that induces the expression of Aβ and an activation status. Meanwhile, we hypothesize a paracrine effect of HHV-6A infection that activates and induces microglia migration to the site of infection

    HHV-6A infection of endometrial epithelial cells affects immune profile and trophoblast invasion

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    Problem: We first reported human herpesvirus (HHV)-6A DNA presence in 43% of endometrial cells from women with idiopathic infertility, whereas no fertile control women harbored the virus. We investigated the effect of HHV-6A infection on the immunological status of the endometrium. Method of study: Endometrial biopsies, uterine flushing, and whole blood samples were collected from 67 idiopathic infertile women (mid-secretory phase). We analyzed the endometrial immunological status evaluating: (a) the effect of HHV-6A infection on endometrial immune profile analyzing the ratio of interleukin (IL)-15/ fibroblast growth factor-inducible 14 (Fn-14) and IL-18/ TNF-related weak inducer of apoptosis (TWEAK) mRNA as a biomarker of endometrial (e)natural killer activation/maturation, angiogenesis, and Th1/Th2 balance; (b) endometrial receptivity to trophoblasts in endometrial 3D in vitro model; (c) natural killer (NK) cells and T cells percentage and subpopulations by flow cytometry. Results: We confirmed the presence of HHV-6A infection in a 40% of idiopathic infertile women, characterized by an immune profile reflecting eNK cell cytotoxic activation and a decrease in CD4+ CD25+ CD127dim/− regulatory T cells. The co-culture of endometrial epithelial cells with spheroids generated from the extravillous trophoblast-derived cell line JEG3 showed a twofold expansion of spheroids on endometrial epithelial-stromal cells (ESC) culture surface from HHV-6A negative women while no expansion was observed on the surface of ESC from HHV-6A positive women. Conclusion: The identification of an effect of HHV-6A infection on endometrial immune status opens new perspectives in idiopathic infertile women care management. In addition, it would be possible to select antiviral therapies as novel, non-hormonal therapeutic approaches to those idiopathic infertile women characterized by the presence of endometrial HHV-6A infection, to increase their pregnancy rate.Problem: We first reported Human herpesvirus (HHV)-6A DNA presence in 43% of endometrial cells from women with idiopathic infertility, whereas no fertile control women harbored the virus. We investigated the effect of HHV-6A infection on the immunological status of the endometrium. Method of study: Endometrial biopsies, uterine flushing, and whole blood samples were collected from 67 idiopathic infertile women (mid-secretory phase). We analyzed the endometrial immunological status evaluating: i) the effect of HHV-6A infection on endometrial immune profile analyzing the ratio of Interleukin (IL)‐15/ Fibroblast growth factor-inducible 14 (Fn‐14) and IL‐18/ TNF-related weak inducer of apoptosis (TWEAK) mRNA as a biomarker of endometrial (e)Natural killer activation/maturation, angiogenesis, and Th1/Th2 balance; ii) endometrial receptivity to trophoblasts in endometrial 3D in vitro model; iii) Natural killer (NK) cells and T cells percentage and subpopulations by flow cytometry. Results: We confirmed the presence of HHV-6A infection in a 40% of idiopathic infertile women, characterized by an immune profile reflecting eNK cell cytotoxic activation and a decrease in CD4+CD25+CD127dim/- regulatory T cells. The co-culture of endometrial epithelial cells with spheroids generated from the extravillous trophoblast-derived cell line JEG3 showed a 2-fold expansion of spheroids on endometrial epithelial-stromal cells (ESC) culture surface from HHV-6A negative women while no expansion was observed on the surface of ESC from HHV-6A positive women. Conclusions: The identification of an effect of HHV-6A infection on endometrial immune status opens new perspectives in idiopathic infertile women care management. In addition, it would be possible to select antiviral therapies as novel, non-hormonal therapeutic approaches to those idiopathic infertile women characterized by the presence of endometrial HHV-6A infection, to increase their pregnancy rate

    Generalized eruptive keratoacanthoma of the Grzybowski type: some considerations on treatment and pathogenesis.

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    A 64‐year‐old male patient presented with a 2‐month history of a generalized mucocutaneous eruption characterized by suspected keratoacanthomas (KAs), umbilicated papules, and small follicular papules, which mainly involved the face, upper limbs, and trunk; the oral mucosa was affected as well. The presence of HPV‐16 DNA harbored in GEKA lesions does not allow any conclusive consideration on the etiological role of HPV infection and the role of HPV in keratoacanthomas remains thus elusive. However, its potential involvement in the pathogenesis of this disorder supports the retinoids as the first therapeutic option. Retinoids could be effective in GEKA treatment not only because of their antitumor properties but also by altering keratinization and inhibiting HPV replication and assembly. In keeping with this, an inverse relation has been observed between concentration of retinoids and HPV DNA within infected epithelial cells.15 We recommend the evaluation of the role of HPV infection in GEKA as meritorious of further investigation

    Human Herpes simplex 1 virus infection of endometrial decidual tissue-derived MSC alters HLA-G expression and immunosuppressive functions

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    Objectives: Mesenchymal stromal/stem cells have immunosuppressive functions. Our previous results demonstrated that one of the players of this immunomodulation can be ascribed to the Human Leukocyte Antigen-G. HLA-G, a non classical HLA class I antigen, is involved in immune tolerance during pregnancy, organ transplantation, autoimmune and inflammatory diseases. In this study we wanted to verify whether human endometrial decidual tissue derived (EDT)-MSC could express HLA-G. Additionally we assessed the permissivity to Human Herpesvirus infections, using HSV-1 as a model, and the possible effect on EDT-MSC immunosuppressive functions towards peripheral blood mononuclear cell (PBMC) proliferation. Methods: We analyzed immune-inhibitory functions and HLA-G expression in human EDT-MSC before and after HSV-1 infection. Results: We observed that EDT-MSC express HLA-G molecules, that partly are responsible for the immune-inhibitory functions of EDT-MSC towards PBMC proliferation. EDT-MSC are permissive for a productive infection by HSV-1, that decreases HLA-G expression and affects EDT-MSC immune-inhibitory functions. Conclusions: We demonstrate that EDT-MSC are susceptible to HSV-1 infection, that reduces HLA-G expression and their immune-inhibitory function. These data could have a clinical implication in the use of EDT-MSC as an immunosuppressant, in particular in steroid-refractory GvHD after allogeneic hematopoietic stem cell transplantation and in autoimmune diseases

    HHV-6A infection of endometrial epithelial cells induces increased endometrial NK cell-mediated cytotoxicity

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    Background: We have recently reported the presence of Human herpesvirus-6A (HHV-6A) DNA in the 43% of endometrial epithelial cells from primary idiopathic infertile women, with no positivity in fertile women. To investigate the possible effect of HHV-6A infection in endometrial (e)NK cells functions, we examined activating/inhibitory receptors expressed by eNK cells and the corresponding ligands on endometrial cells during HHV-6A infection. Methods: Endometrial biopsies and uterine flushing samples during the secretory phase were obtained from 20 idiopathic infertile women and twenty fertile women. HHV-6A infection of endometrial epithelial cells was analyzed by Real-Time PCR, immunofluorescence and flow cytometry. eNKs receptors and endometrial ligands expression were evaluated by immunofluorescence and flow cytometry. Results: We observed the presence of HHV-6A infection (DNA, protein) of endometrial epithelial cells in the 40% of idiopathic infertile women. The eNK from all the subgroups expressed high levels of NKG2D and NKG2A receptors. Functional studies showed that NKG2D activating receptor and FasL are involved in the acquired cytotoxic function of eNK cells during HHV-6A infection of endometrial epithelial cells. In the presence of HHV-6A infection, eNK cells increased expression of CCR2, CXCR3 and CX3CR1 chemokine receptors (p = 0.01) and endometrial epithelial cells up-modulated the corresponding ligands: MCP1 (Monocyte chemotactic protein 1, CCL2), IP-10 (Interferon gamma-induced protein 10, CXCL10) and Eotaxin-3 (CCL26). Conclusion: Our results, for the first time, showed the implication of eNK cells in controlling HHV-6A endometrial infection and clarify the mechanisms that might be implicated in female idiopathic infertility

    “Hemophagocytic Lymphohistiocytosis after EBV reactivation and ibrutinib treatment in relapsed/refractory Chronic Lymphocytic Leukemia”

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    Hemophagocytic Lymphohistiocytosis (HLH) is a rare syndrome characterized by ineffective T-cell and NK response. We report the clinical course of a patient with relapsed CLL who developed acute symptoms soon after starting ibrutinib. Hyperpyrexia, splenomegaly, hyperferritinemia, hypertriglyceridemia, cytopenias, and a typical cytokine pattern, i.e. high interleukin (IL)−6, IL10 and IL18, were consistent with a diagnosis of HLH. Coexistent Epstein Barr virus reactivation was documented. Ibrutinib-induced impairment of NK degranulation, associated with EBV reactivation and CLL-related immunodeficiency may have contributed to the development of HLH in our patient

    The association between functional HLA-G 14 bp insertion/deletion and +3142 C > G polymorphisms and susceptibility to multiple sclerosis

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    We aimed to investigate two main polymorphisms in the 3' untranslated region (3'UTR) of the HLA-G gene [14 bp insertion/deletion (INS/DEL) and +3142 C > G] and to assess their impact on the soluble HLA-G (sHLA-G) production in patients with multiple sclerosis (MS). This study included 60 patients with relasping-remitting (RR) MS and 112 healthy donors (HD). Mutations were identified by PCR and PCR–RFLP, and serum sHLA-G quantification was performed by ELISA. For the 14 bp INS/DEL polymorphism, variants frequencies were similar in patients and controls, whereas a significant increased frequency of the +3142 G allele was found in MS patients compared to HD (63.4% vs 52.3%, p = 0.04; OR = 1.58, 95%CI = 1.003–2.48). In addition, an association was found between MS susceptibility and the haplotypes regrouping both studied polymorphisms. Indeed, the 14 bp DEL/ + 3142 G haplotype frequency was significantly increased in MS patients compared to HD (20.8% vs 12.5%, p = 0.04, OR = 1.84). On the other hand, no associations were detected between both polymorphisms and clinical parameters, except the lower age of disease onset (ADO) in patients with the +3142 C/C genotype. Moreover, our study doesn't show any significant variation of sHLA-G serum levels between patients and controls. Our findings showed that the +3142 C > G, but not the 14 bp INS/DEL, polymorphism may constitute a genetic susceptibility factor to MS in the Tunisian population. However, no association was found between the two polymorphisms and sHLA-G serum levels
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