Virus sensing receptors in cellular infectivity of influenza A virus.

An innate immune response is essential to mobilize protective immunity upon the infection of respiratory epithelial cells with influenza A virus (IAV). The response is classified as early (nonspecific effectors), local systematic (effector cells recruitment) and late (antigen to lymphoid organ transport, naive B and T cells recognition, effector cells clonal expansion and differentiation). Virus particles are detected by the host cells as non-self by various sensors that are present on the cell surface, endosomes and cytosol. These sensors are collectively termed as pattern recognition receptors (PRRs). The PRRs distinguish unique molecular signatures known as pathogen-associated molecular pattern, which are present either on the cell surface or within intracellular compartments. PRRs have been classified into five major groups: C-Type Lectin Receptor (CLR), Toll-like receptor (TLR), Nod-like receptor (NLR), Retinoic acid-inducible gene-I-like receptor (RLR), which play a role in innate immunity to IAV infection, and the pyrin and hematopoietic interferon-inducible nuclear (PYHIN) domain protein. Here, we discuss the role of PRRs in cellular infectivity of IAV and highlight the recent progress.

Development of a Simple, Fast, and Cost-Effective Nanobased Immunoassay Method for Detecting Norovirus in Food Samples.

This study presents a quick, low-cost, and easy technique for the detection of norovirus in several food samples, including cucumber, lettuce, and chicken. The developed sandwich immunoassay method depends on employing nanotechnology for the detection step. Lactoferrin immobilized on activated Q-tips cotton swabs was used as a general capturing reagent to bind viruses from the sample surface. The cotton swabs were then submerged in a gold nanoparticle solution, which had previously decorated with a specific antibody for noroviruses. Positive samples retained the red color of the gold nanoparticles on the surface of Q-tips, even after washing, while the negative control samples easily lost their color through washing. The results confirmed that the developed assay has superior sensitivity and selectivity with a LOD between 10 and 53 pfu/mL for all tested samples. In light of the difficulty, complexity, and high cost of the methods recently used for detecting viruses in food samples, this method presents a promising reliable technique that can be employed for the rapid detection of norovirus in food samples with an acceptable accuracy.

Human papillomavirus epidemiology in populations with normal or abnormal cervical cytology or cervical cancer in the Middle East and North Africa: A systematic review and meta-analysis.

BACKGROUND: Human papillomavirus (HPV), one of the most common sexually transmitted viral infections worldwide, is the leading cause of cervical cancer. In Middle East and North Africa (MENA) Region HPV data is at scarce, and most of the countries haven't implemented any vaccination programs. This present meta-analysis and systematic review aimed to describe human papillomavirus (HPV) epidemiology by clinical subgroups in the (MENA) region. METHODS: Studies assessing HPV prevalence rates were systematically reviewed, and the selected articles were reported following the PRISMA guideline. Random-effects meta-analyses and meta-regression were used to estimate HPV pooled mean prevalence rates and their association with other factors. RESULTS: For the cervical cancer population in the MENA region, the pooled HPV prevalence rate was 81% (95% CI, 70%-90%). HPV detected in cervical cancer samples was most prevalent in the Maghreb countries (88%; 95% CI, 78%-96%) and least prevalent in Iran (73%; 95% CI, 62%-83%).For the subgroup with abnormal-cervical cytology in the MENA region, the pooled HPV prevalence rate was 54% (95% CI, 41%-67%), with the highest prevalence reported in Northeast Africa (94%; 95% CI, 91%-96%), and the lowest prevalence in the Levant region (31%; 95 CI, 16%-49%). In the general population subgroup in the MENA region, the pooled HPV prevalence rate was 16% (95% CI, 14%-17%), HPV was most prevalent in the Northeast Africa region (21%; 95 CI, 7%-40%) and least prevalent in the Levant region (7%; 95 CI, 2%-14%). CONCLUSION: The present meta-analysis comprehensively described the current HPV prevalence rates in the MENA region and found that the rates have continued to increase with time, especially in African regions. Designing personalized awareness and vaccination programs that respect the various cultural and religious values remains the main challenge in prevention of cervical cancer in the MENA region.

Human papillomaviruses: The cervical cancer saga in developing countries.

Cervical cancer is the fourth most common cancer affecting women, with worldwide annual incidence and mortality rates of 528,000 and 266,000, respectively, according to the World Health Organization. It is well established that cervical cancer is predominantly caused by a persistent human papillomavirus (HPV) infection of cervical cells. Increasing numbers of studies have investigated HPV and cervical cancer, contributing greatly to the global knowledge and unraveling some of the critical questions regarding HPV transmission, infection, and prevention. However, despite these studies, our knowledge is far from complete and much remains to be discovered. Although molecular detection and HPV prophylactic approaches have greatly advanced in recent years, approximately 85% of the global burden of mortality from cervical cancer still occurs in developing countries. Clinical and molecular epidemiological studies have demonstrated a need for developing countries in general to adopt cervical screening and vaccination programs. However, studies examining cervical cancer screening modalities and HPV prevalence as well as whether HPV vaccination programs should be implemented are lacking at the national level in some developing countries. Therefore, this review describes the current status of HPV in developing countries, presenting some of the existing challenges in implementing cervical screening and HPV vaccination programs.

Expression of variable viruses as herpes simplex glycoprotein D and varicella zoster gE glycoprotein using a novel plasmid based expression system in insect cell.

Several prokaryotic and eukaryotic expression systems have been used for in vitro production of viruses' proteins. However eukaryotic expression system was always the first choice for production of proteins that undergo post-translational modification such as glycosylation. Recombinant baculoviruses have been widely used as safe vectors to express heterologous genes in the culture of insect cells, but the manipulation involved in creating, titrating, and amplifying viral stocks make it time consuming and laborious. Therefore, to facilitate rapid expression in insect cell, a plasmid based expression system was used to express herpes simplex type 1 glycoprotein D (HSV-1 gD) and varicella zoster glycoprotein E (VZV gE). Recombinant plasmids were generated, transfected into insect cells (SF9), and both glycoproteins were expressed 48 h post-infection. A protein with approximately molecular weight of 64-kDa and 98-kDa for HSV-1 gD and VZV gE respectively was expressed and confirmed by SDS. Proteins were detected in insect cells cytoplasm and outer membrane by immunofluorescence. The antigenicity and immunoreactivity of each protein were confirmed by immunoblot and ELISA. Results suggest that this system can be an alternative to the traditional baculovirus expression for small scale expression system in insect cells.