Picornaviruses have evolved to hijack host cellular machinery, including the autophagic pathway. However, the mechanisms remain largely unclear. We use coxsackievirus B3 (CVB3) as a model organism to explore the possible role of picornavirus subversion of the autophagic pathway in viral infection. Our in vivo and in vitro experiments demonstrate that CVB3 infection causes a significant, albeit incomplete, inhibition of autophagic flux by limiting the fusion of autophagosomes with lysosomes and/or late endosomes. Furthermore, we show that CVB3 specifically targets SNARE protein SNAP29 and adaptor protein PLEKHM1, two critical proteins known to regulate autophagosome fusion, for cleavage through the catalytic activity of viral proteinase 3C, ultimately impairing the formation of SNARE complexes. Finally, we demonstrate that loss of SNAP29/PLEKHM1 inhibits autophagic flux, resulting in increased viral replication. Collectively, our study reveals a mechanism that supports an emerging model whereby CVB3 hijacks the autophagic machinery to facilitate its own propagation.

Cell autonomous immunity is the ability of individual cells to initiate a first line of host defense against invading microbes, such as viruses. Autophagy receptors, a diverse family of multivalent proteins, play a key role in this host response by detecting, sequestering, and eliminating virus in a process termed virophagy. To counteract this, positive-stranded RNA viruses, such as enteroviruses, have evolved strategies to circumvent the host autophagic machinery in an effort to promote viral propagation; however, the underlying mechanisms remain largely unclear. Here we studied the interaction between coxsackievirus B3 (CVB3) and the autophagy receptor SQSTM1 (sequestosome 1)/p62 and CALCOCO2/NDP52 (calcium binding and coiled-coil domain-containing protein 2/nuclear dot 10 protein 52). We demonstrated that SQSTM1 and CALCOCO2 differentially regulate CVB3 infection. We showed that knockdown of SQSTM1 causes increased viral protein production and elevated viral titers, whereas depletion of CALCOCO2 results in a significant inhibition of viral growth. Both receptors appear to have a role in virophagy through direct interaction with the viral capsid protein VP1 that undergoes ubiquitination during infection. Further investigation of the proviral mechanism of CALCOCO2 revealed that CALCOCO2, but not SQSTM1, suppresses the antiviral type I interferon signaling by promoting autophagy-mediated degradation of the mitochondrial antiviral signaling (MAVS) protein. Moreover, we demonstrated that viral proteinase 2A-mediated cleavage of SQSTM1 at glycine 241 impairs its capacity to associate with viral capsid, whereas cleavage of CALCOCO2 by viral proteinase 3C at glutamine 139, generates a stable C-terminal fragment that retains the proviral function of full-length CALCOCO2. Altogether, our study reveals a mechanism by which CVB3 targets selective autophagy receptors to evade host virophagy.

KRAS mutant ( KRAS mut ) lung adenocarcinoma is a refractory cancer without available targeted therapy. The current study explored the possibility to develop coxsackievirus type B3 (CVB3) as an oncolytic agent for the treatment of KRAS mut lung adenocarcinoma. In cultured cells, we discovered that CVB3 selectively infects and lyses KRAS mut lung adenocarcinoma cells (A549, H2030, and H23), while sparing normal lung epithelial cells (primary, BEAS2B, HPL1D, and 1HAEo) and EGFR mut lung adenocarcinoma cells (HCC4006, PC9, H3255, and H1975). Using stable cells expressing a single driver mutation of either KRAS G12V or EGFR L858R in normal lung epithelial cells (HPL1D), we further showed that CVB3 specifically kills HPL1D- KRAS G12V cells with minimal harm to HPL1D- EGFR L858R and control cells. Mechanistically, we demonstrated that aberrant activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and compromised type I interferon immune response in KRAS mut lung adenocarcinoma cells serve as key factors contributing to the sensitivity to CVB3-induced cytotoxicity. Lastly, we conducted in vivo xenograft studies using two immunocompromised mouse models. Our results revealed that intratumoral injection of CVB3 results in a marked tumor regression of KRAS mut lung adenocarcinoma in both non-obese diabetic (NOD) severe combined immunodeficiency (SCID) gamma (NSG) and NOD-SCID xenograft models. Together, our findings suggest that CVB3 is an excellent candidate to be further developed as a targeted therapy for KRAS mut lung adenocarcinoma.

BackgroundThe incidence of cryptococcal meningitis (CM) and tuberculous meningitis (TBM) have gradually increased in recent years. These two types of meningitis are easily misdiagnosed which leads to a poor prognosis. In this study we compared differences of clinical features and prognostic factors in non-HIV adults with CM and TBM.MethodsWe retrospectively reviewed the medical records of CM and TBM patients from January 2008 to December 2015 in our university hospital in China. The data included demographic characteristics, laboratory results, imaging findings, clinical outcomes.ResultsA total of 126 CM and 105 TBM patients were included. CM patients were more likely to present with headache, abnormal vision and hearing, and they might be less prone to fever and cough than TBM patients (P < 0.05). Higher percentage of CM patients presented with cerebral ischemia/infarction and demyelination in brain MRI than TBM patients (P < 0.05). CM patients had lower counts of WBC in CSF, lower total protein in CSF and serum CD4/CD8 ratio than TBM patients (P < 0.05). After three months of treatment, CM group have worse outcome than TBM group (P < 0.05). Multivariate analysis showed that age more than 60y (OR = 4.981, 95% CI: 1.955–12.692, P = 0.001), altered mentation (OR = 5.054, 95% CI: 1.592–16.046, P = 0.006), CD4/CD8 ratios < 1 (OR = 8.782, 95% CI: 2.436–31.661, P = 0.001) and CSF CrAg ≥ 1:1024 (OR = 4.853, 95% CI: 1.377–17.098, P = 0.014) were independent risk factors for poor prognosis for CM patients. For TBM patients, hydrocephalus (OR = 7.290, 95% CI: 1.630–32.606, P = 0.009) and no less than three underlying diseases (OR = 6.899, 95% CI: 1.766–26.949, P = 0.005) were independent risk factors, headache was a protective factor of prognosis.ConclusionsOur study provided some helpful clues in the differential diagnosis of non-HIV patients with CM or TBM and identified some risk factors for the poor prognosis of these two meningitis which could help to improve the treatment outcome. Further studies are worth to be done.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-2126-6) contains supplementary material, which is available to authorized users.

The crisis of antimicrobial resistance is worsening and has become a major public safety problem in China, seriously endangering human and animal health and ecological environment. Gram-negative bacterial resistance in China is severe: the related pathogens mainly include carbapenem-resistant Acinetobacter, Pseudomonas aeruginosa and Klebsiella pneumoniae. Surging antimicrobial consumption and irrational use of antimicrobials are the main causes of resistance. In China, a variety of strategies are implemented to control the antimicrobial resistance in hospitals, agriculture and environment. However, there is still a long way to go to strengthen the drug resistance surveillance, to reduce the emergence of drug-resistant bacteria, and to find new antimicrobials and therapies for drug-resistant bacteria. Controlling the antimicrobial resistance crisis takes great efforts from the whole society.

cryptococcosis is a systemic infection and it may occur in immunocompromised and immunocompetent hosts. In order to better understand the clinical characteristics of patients with PC in different immune status, we retrospectively investigated the clinical, radiological, and treatment profiles of immunocompetent and immunocompromised patients with PC during a 10-year period (2008-2017). As a result, out of 136 patients, 94 (69.1%) were immunocompromised hosts. For the PC patients without CNS involvement, higher percentage of immunocompetent patients (39.5%, 15/38) had asymptomatic presentation than immunocompromised patients (6.3%, 3/48) (P < 0.05). Multiple pulmonary nodules (72.7%, 56/77), ground-glass attenuation/interstitial changes (94.4%, 17/18) and cavitation (88.6%, 31/35) were significantly frequent in immunocompromised patients (P < 0.05). A total of 47 patients were misdiagnosed as tuberculosis or tumors based on ct signs. pc was likely to be misdiagnosed as tuberculosis in immunocompromised patients (88.2%, 15/17), and tumor was more likely to be considered in immunocompetent patients (43.3%, 13/30). Immunocompetent patients accounted for 80% (24/30) of patients with definite diagnosis on surgical lung biopsy. Fluconazole monotherapy can achieve good clinical outcome in most PC patients without central nervous system (CNS) involvement (91.5%, 54/59). After 3 months of treatment, 92.7% (38/41) patients have improved imaging findings. In conclusion, pc has diverse imaging manifestations and it is easily misdiagnosed. Lobectomy should be carefully selected in immunocompetent patients with a single lung lesion. Fluconazole monotherapy is preferred for pc patients without cnS involvement.

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Background: Fever of unknown origin (FUO) is commonly defined as fever higher than 38.3 ℃ on several occasions during at least 3 weeks with uncertain diagnosis after a number of obligatory investigations. It is a special type of fever and a common disease in internal medicine. However, due to its complex etiology, lack of characteristic clinical manifestations, and insufficient laboratory examination indicators, it often baffles clinicians in diagnosis. We herein present a study of the etiological factors and clinical features of classic fever of unknown origin (FUO) to provide help for related clinical diagnosis and treatment.Methods: A total of 1,641 cases of patients with classic FUO hospitalized in West China Hospital of Sichuan University between January 1, 2011 and December 31, 2017, were collected, and the etiological factors of classic FUO were analyzed. A special effort was made to explore and screen the laboratory indicators related to infectious diseases, and the above data were compared with the clinical features of tuberculosis and lymphoma, which are difficult to diagnose.Results: Among the 1,641 patients, 1,504 were finally diagnosed through various types of examination or diagnostic methods, and the diagnosis rate was 91.65%. Among all the causes of the 1,641 cases of FUO, 48.69% [799] were infectious diseases, of which tuberculosis was the most common, accounting for 19.50%[320]. Connective tissue diseases were responsible for 19.26% [316] of cases, of which adult-onset Still's disease (AOSD) was the most common, comprising 89 (5.42%) of the cases; 16.94% [278] were neoplastic diseases, and lymphoma (143, 8.71%) cases, was the most common malignant tumor; 6.76% [111] were other diseases; and in 8.35% [137] of cases, the cause was unclear. Through comparative analysis of tuberculosis and lymphoma, no significant differences were found between the symptoms, signs, and non-specific routine examination results of the two diseases. The diagnosis of these diseases was more dependent on tuberculosisrelated examinations and pathological examinations.Conclusions: Infectious diseases are the principal cause of classic FUO, in which tuberculosis accounts for a large proportion. Non-infectious diseases that cause FUO are mainly connective tissue diseases and malignant tumors. Of the various causes of classic FUO, tuberculosis and lymphoma are relatively difficult to diagnose. In most cases, the causes of classic FUO can be ascertained.