Three unique Sendai virus antigenic peptides screened from nucleocapsid protein by overlapping peptide array

Sendai virus (SeV) is strictly monitored in laboratory rodents. Currently, complete virions have been used as antigens in SeV serological tests. However, the complexity of SeV virion antigen limits the accuracy of the diagnostic method. In the current study, complete SeV virion antigen was separated on SDS-PAGE and analyzed, with nucleocapsid protein (NP) showing predominant antigenicity. A peptide array containing overlapping 14-mer peptides covering the entire NP was developed. The array used SeV positive serum and resulted in four antigenic linear peptides being identified, which were located in the carboxyl-terminus of NP. The four peptides were coated on ELISA plates and tested with SeV positive and SeV negative sera, and the antigenicity of three peptides, NP413–428, NP473–490 and NP507–524, was confirmed. Mixture of the three peptides showed comparable sensitivity and better specificity in clinical rat sera ELISA tests compared with complete SeV virion antigen. In conclusion, the three peptides, NP413–428, NP473–490 and NP507–524, would be good candidates as linear antigens for SeV detection.     

Presence of enteroviruses in recreational water in Wuhan,China

Contaminated recreational waters pose a public health concern, as the potential for waterborne diseases exists in water contaminated with human fecal waste. Worldwide, bacterial indicators such as Escherichia coli, enterococci, and total and fecal coliform are used as indicators of water quality. However, enteric viruses also present a public health concern and their presence cannot always be determined based on bacterial indicators. This study explores the use of molecular detection methods of enteric viruses as indicators of fecal contamination. Four viruses, enterovirus, norovirus genogroups I and II, and male-specific FRNA coliphage, were tested in this study. Highly sensitive RT-PCR methods developed at the University of Hawaii at Manoa were utilized to evaluate environmental samples collected from three lakes in Wuhan, Hubei Province, China. Sixteen of twenty-five sites tested positive for at least one virus. Enterovirus was the most commonly detected virus, followed by norovirus genogroup I. These findings support the use of molecular detection methods to test for enteric virus presence in recreational freshwater sources in China as alternative water quality indicators, and utilize recently developed, highly sensitive methods of detection of these viruses. In addition, these findings suggest that there is substantial fecal contamination of the three lakes tested in this study.     

Activation of Toll-like receptor 2 increases macrophage resistance to HIV-1 infection

Patients infected with HIV-1, the etiological agent of AIDS, have increased intestinal permeability, which allows for the passage of microbial products, including Toll-like receptor (TLR) ligands, into circulation. The exposure of HIV-1-infected cells to certain TLR agonists affects viral replication, but studies associating viral production with the activation of TLR2 in HIV-1-infected cells are rare and controversial. Here, we report that the TLR2 ligands Zymosan and Pam3CSK4 potently inhibit HIV-1 replication in acutely infected monocyte-derived macrophages and the exposure to TLR2 ligands prior to infection renders macrophages refractory to HIV-1 production. Macrophage treatment with Pam3CSK4 did not change the cellular expression of the HIV-1 entry receptors CD4 and CCR5. Both TLR2 ligands increased the macrophage production of β-chemokines and IL-10, and the blockage of these soluble factors prevented the inhibitory effect of TLR2 activation on HIV-1 replication. Our findings show that the direct engagement of TLR2 in HIV-1-infected macrophages increase cellular resistance to HIV-1 infection, and that controlling HIV-1 replication with agonists for TLR2 might have implications for the development of antiretroviral therapies.     

Understanding HIV-Related Pill Aversion as a Distinct Barrier to Medication Adherence

Abstract

Pill aversion, defined as difficulty swallowing pills without identifiable medical cause, is a poorly characterized barrier to sustained viral suppression for many HIV-infected persons. We aimed to quantify the frequency of self-reported pill aversion, characterize its symptoms, and measure the association between self-reported pill aversion and missing antiretroviral doses. This is a prospective, observational, exploratory survey study of English-speaking persons living with HIV (PLHIV) at a single urban tertiary outpatient clinic. Participants completed anonymous questionnaires about their experiences of swallowing antiretroviral pills. The primary outcome was skipping pills due to pill aversion symptoms. Of 384 participants, a quarter (25.5%) skipped pills due to pill aversion symptoms. Younger age, being Non-Hispanic Black or Hispanic, not being married or partnered, having public insurance, not being employed, having less than a college education, and having a mental health diagnosis were associated with skipping pills due to pill aversion. On multivariable regression analyses, PLHIV who skipped pills were more likely to report symptoms of gagging, nausea at the time of swallowing, and heavy feeling in the stomach, as well as being bothered by the taste, smell, and size of the pills. PLHIV who skipped pills were also more likely to report negative and fear-based emotions about pill-taking than PLHIV who did not skip pills due to pill aversion. HIV-related pill aversion may represent a significant and frequent barrier to adherence in an adult HIV population.     

The human JC polyomavirus (JCPyV): virological background and clinical implications

JC polyomavirus (JCPyV) was the first of now 12 PyVs detected in humans, when in 1964, PyV particles were revealed by electron microscopy in progressive multifocal leukoencephalopathy (PML) tissues. JCPyV infection is common in 35–70% of the general population, and the virus thereafter persists in the renourinary tract. One third of healthy adults asymptomatically shed JCPyV at approximately 50 000 copies/mL urine. PML is rare having an incidence of <0.3 per 100 000 person years in the general population. This increased to 2.4 per 1000 person years in HIV‐AIDS patients without combination antiretroviral therapy (cART). Recently, PML emerged in multiple sclerosis patients treated with natalizumab to 2.13 cases per 1000 patients. Natalizumab blocks α4‐integrin‐dependent lymphocyte homing to the brain suggesting that not the overall cellular immunodeficiency but local failure of brain immune surveillance is a pivotal factor for PML. Recovering JCPyV‐specific immune control, e.g., by starting cART or discontinuing natalizumab, significantly improves PML survival, but is challenged by the immune reconstitution inflammatory syndrome. Important steps of PML pathogenesis are undefined, and antiviral therapies are lacking. New clues might come from molecular and functional profiling of JCPyV and PML pathology and comparison with other replicative pathologies such as granule cell neuronopathy and (meningo‐)encephalitis, and non‐replicative JCPyV pathology possibly contributing to some malignancies. Given the increasing number of immunologically vulnerable patients, a critical reappraisal of JCPyV infection, replication and disease seems warranted.     

Can non-selective beta-blockers prevent hepatocellular carcinoma in patients with cirrhosis?

Hepatocellular carcinoma is the main liver-related cause of death in patients with compensated cirrhosis. The early phases are asymptomatic and the prognosis is poor, which makes prevention essential. We propose that non-selective beta-blockers decrease the incidence and growth of hepatocellular carcinoma via a reduction of the inflammatory load from the gut to the liver and inhibition of angiogenesis.     

AAV8 transduction capacity is reduced by prior exposure to endosome-like pH conditions

Adeno-associated virus(AAV) is an essential instrument in the neuroscientist's toolkit, which allows delivery of DNA to provide labeling with fluorescent proteins or genetic instructions to regulate gene expression. In the field of neural regeneration, the transduction of neurons enables the observation and regulation of axon growth and regeneration, and in the future will likely be a mechanism for delivering molecular therapies to promote sprouting and regeneration after central nervous system injury. Traditional formulations of AAV preparations permit efficient viral transduction under physiologic conditions, but an improved understanding of the mechanistic limitations of AAV transduction may facilitate production of more resilient AAV strains for investigative and therapeutic purposes. We studied AAV transduction in the context of prior exposure of AAV serotype 8(AAV8) to environmental p H within the range encountered during endosomal endocytosis(p H 7.4 to p H 4.4), during which low p H-triggered structural and autoproteolytic changes to the viral capsid are believed to be necessary for endosome escape and virus uncoating. Due to the fundamental nature of these processes, we hypothesized that premature exposure of AAV8 particles to acidic p H would decrease viral transduction of HT1080 cells in vitro, as measured by fluorescent reporter gene expression using high-content imaging analysis. We found that increasingly acidic incubation conditions were associated with concomitant reductions in transduction efficiency, and that quantitative levels of reporter gene expression in transduced cells were similarly decreased. The biggest decrease in transduction occurred between p H 7.4 and p H 6.4, suggesting the possible co-occurrence of a p H-associated event and viral inactivation within that range. Taken together, these findings indicate that exposure of AAV8 to acidic p H for as little as 1 hour is deleterious to transduction ability. Future studies are necessary to understand the p H-associated causative mechanisms involved. This study was approved by the University of Miami Institutional Animal Care and Use Committee, USA(Protocol #18-108-LF) on July 12, 2018.     

Coinfection of other respiratory pathogens and HIV in COVID‐19 patients: Is there a pattern?

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS‐Cov‐2) has led to the elaboration of multiple studies to increase knowledge and understanding, hence, having the ability to accomplish an adequate and timely diagnosis and give an optimal treatment according to the patient's condition. The clinical manifestations of COVID‐19 pose a series of challenges both in understanding and delimiting the disease secondary to the SARS‐CoV‐2 infection. This is due to the fact that the main axis of this disease is the endothelial compromise and the production of a “cytokine storm,” triggering multiple organ failure and death. Given that a complete understanding of its pathophysiology and clinical behavior has not yet been achieved, we wondered if coinfection with other respiratory viruses modifies its performance and outcomes described so far. A literature search was performed, obtaining 68 articles, of which 25 were analyzed. The analysis showed us that there is a high variety both in the types of associated infections and in the clinical behavior of patients and their outcomes. Therefore, we consider that the search for other infections should be performed exhaustively, especially in those cases that may be susceptible to treatment such as Influenza A, human immunodeficiency virus, or bacterial infections. As well as optimize the analysis of these cases and establish if there are characteristics that allow establishing the possibility of carrying an additional infection to that of SARS‐CoV‐2 and the implications for the management and prognosis of the patient.