Aberrant expression of IFI16 in the intestinal epithelia from inflammatory bowel disease is induced by pro-inflammatory cytokines

Background: For gastric cancers, the benefits of adjuvant radiochemotherapy and of perioperative chemotherapy have been demonstrated since 2001 and 2006 respectively. The aim of this study was to evaluate the diffusion of adjuvant treatments in a French population. Methods: 334 incident gastric cancers UICC Stage IB, II, III or IVM0 resected for cure and recorded in the Burgundy digestive cancer registry were retrospectively included. Patients were classified as having received an effective adjuvant treatment if they had been treated by adjuvant radiochemotherapy since 2001 or perioperative chemotherapy since 2006. Results: The proportion of patients treated with an effective adjuvant treatment increased from 21.8% (2001-2005) to 40.1% (2006-2009). Patients treated in 2006-2009 were twice as likely to receive effective adjuvant treatment as those treated during the period 2001-2005. During the 2004-2009 period, 62.4% of cases were presented in a multidisciplinary team meeting. These patients were almost three times more likely to receive effective adjuvant treatment than patients excluded from multidisciplinary team consultation. Age was a significant factor, independent of comorbidities. Conclusion: Administration of adjuvant treatment is still far from being considered a reference regimen in routine practice for R0 resected gastric cancer. The increase in multidisciplinary team meetings should improve the situation

Analysis of human beta papillomavirus and Merkel cell polyomavirus infection in skin lesions and eyebrow hair bulbs from a cohort of chronic lymphocytic leukaemia patients.

BACKGROUND: Research consistently demonstrates an increased incidence of skin cancer in the immunocompromised host, including patients with chronic lymphocytic leukaemia (CLL) and organ transplant recipients (OTRs). Active human beta papillomavirus (\u3b2-HPV) infection has been found in OTR skin lesions, suggesting their possible involvement in skin carcinogenesis. Although less frequent, Merkel cell polyomavirus (MCPyV) has also been reported in cases of skin cancer. OBJECTIVES: To investigate: i) potential correlations between patient clinical features and skin cancer development; and ii) the presence of \u3b2-HPV and MCPyV DNA and protein markers in skin lesions and hair bulbs from CLL patients. METHODS: The clinical features of 293 patients with CLL were analysed according to the presence or absence of skin lesions. \u3b2-HPV and MCPyV infection was investigated in skin lesions and hair bulbs from the study cohort by both PCR analysis and immunohistochemical screening. RESULTS: No significant correlations were observed between any of the analysed haematological parameters and the development of skin cancer. PCR analysis revealed the presence of \u3b2-HPV and MCPyV DNA in skin lesions, and 83% of positivity for MCPyV DNA in hair bulbs, while systematic immunohistochemical analysis of all the lesions failed to detect any expression of the viral proteins \u3b2-HPV E4, L1 or MCPyV LTAg. CONCLUSIONS: Overall, our data indicate that carriage of \u3b2-HPV and MCPyV in the lesional skin and hair bulbs from CLL patients without any evident reactivation at skin tumour sites most likely represents coincidental rather than causal infection. This contrasts with our previous findings in relation to OTR-derived skin lesions

Innate Nuclear Sensor IFI16 Translocates into the Cytoplasm during the Early Stage of In Vitro Human Cytomegalovirus Infection and Is Entrapped in the Egressing Virions during the Late Stage

Intrinsic immune mechanisms mediated by constitutively expressed proteins termed “restriction factors” provide frontline antiviral defense. We recently demonstrated that the DNA sensor IFI16 restricts human cytomegalovirus (HCMV) replication by downregulating viral early and late but not immediate-early mRNAs and their protein expression. We show here that at an early time point during the in vitro infection of low-passage-number human embryonic lung fibroblasts, IFI16 binds to HCMV DNA. However, during a later phase following infection, IFI16 is mislocalized to the cytoplasmic virus assembly complex (AC), where it colocalizes with viral structural proteins. Indeed, upon its binding to pUL97, IFI16 undergoes phosphorylation and relocalizes to the cytoplasm of HCMV-infected cells. ESCRT (endosomal sorting complex required for transport) machinery regulates the translocation of IFI16 into the virus AC by sorting and trafficking IFI16 into multivesicular bodies (MVB), as demonstrated by the interaction of IFI16 with two MVB markers: Vps4 and TGN46. Finally, IFI16 becomes incorporated into the newly assembled virions as demonstrated by Western blotting of purified virions and electron microscopy. Together, these results suggest that HCMV has evolved mechanisms to mislocalize and hijack IFI16, trapping it within mature virions. However, the significance of this IFI16 trapping following nuclear mislocalization remains to be established. IMPORTANCE Intracellular viral DNA sensors and restriction factors are critical components of host defense, which alarm and sensitize immune system against intruding pathogens. We have recently demonstrated that the DNA sensor IFI16 restricts human cytomegalovirus (HCMV) replication by downregulating viral early and late but not immediate-early mRNAs and their protein expression. However, viruses are known to evolve numerous strategies to cope and counteract such restriction factors and neutralize the first line of host defense mechanisms. Our findings describe that during early stages of infection, IFI16 successfully recognizes HCMV DNA. However, in late stages HCMV mislocalizes IFI16 into the cytoplasmic viral assembly complex and finally entraps the protein into mature virions. We clarify here the mechanisms HCMV relies to overcome intracellular viral restriction, which provides new insights about the relevance of DNA sensors during HCMV infection

NUOVO MECCANISMO DI EVASIONE DEL CITOMEGALOVIRUS UMANO DAL FATTORE DI RESTRIZIONE IFI16

Il sistema immunitario dispone di meccanismi di difesa cellulari definiti \u201cintrinseci\u201d che conferiscono alle cellule la capacit\ue0 di resistere ai microrganismi patogeni. Componenti essenziali del SI innato sono i cosiddetti \u201cfattori di restrizione\u201d espressi costitutivamente e attivi prima che un patogeno penetri all\u2019interno delle cellule. Il Citomegalovirus umano (HCMV) ha evoluto meccanismi per evadere lo stato antivirale indotto da tali fattori. Tra i fattori di restrizione intracellulari proteine codificate dalla famiglia di geni Interferon-inducibili HIN200 sono in grado di inibire la replicazione degli Herpesvirus. In particolare il nostro gruppo di ricerca ha recentemente dimostrato che IFI16 agisce come fattore di restrizione verso HCMV inibendo l\u2019espressione dei geni virali precoci e tardivi (Gariano, Dell\u2019Oste et al Plos Path 2012). Nel presente lavoro sono stati studiati i meccanismi che permettono agli Herpesvirus di eludere i sistemi di riconoscimento innato per stabilire infezioni persistenti, con particolare riferimento al processo di evasione che permette ad HCMV di interferire con l\u2019attivit\ue0 antivirale di IFI16. Analisi in microscopia confocale hanno evidenziato in fibroblasti primari (HELF) infettati da HCMV (AD169) la delocalizzazione di IFI16 dal nucleo a partire da 24 ore post-infezione. Per chiarire i meccanismi molecolari alla base di questo fenomeno \ue8 stata analizzata la chinasi virale pUL97, componente essenziale del complesso di egressione dal nucleo di HCMV. Abbiamo dimostrato che pUL97 lega e fosforila IFI16 determinando la sua uscita dal nucleo delle cellule infette. Analisi in microscopia elettronica hanno inoltre rilevato IFI16 all\u2019interno di virioni maturi, indicando che per sovvertire l\u2019attivit\ue0 antivirale di IFI16 HCMV delocalizza la proteina e la incorpora nelle particelle virali mature. Nell\u2019insieme questi risultati evidenziano un nuovo meccanismo di evasione operato da HCMV nei confronti dell\u2019attivit\ue0 di restrizione dei geni indotti da Interferon tra i quali la proteina IFI16 svolge un ruolo centrale