Oncolytic Virotherapy.

Oncolytic virotherapy opens up avenues for cancer treatment by selectively targeting the cancer cells and destructs them either through direct lysis or by inducing an immune response in the tumor microenvironment. This platform technology utilizes a diverse range naturally existing or genetically modified oncolytic viruses for their immunotherapeutic potential. Due to the limitations associated with the conventional cancer therapies, immunotherapies using oncolytic viruses (OVs) have generated a great deal of interest in the modern era. Currently, several oncolytic viruses have entered clinical trials and have proven successful for a number of different cancers as monotherapies as well as in combination with the standard treatment methods like chemotherapy, radiotherapy, or immunotherapy. Efficacy of OVs can be further enhanced by utilizing several approaches. Efforts of the scientific community for getting better knowledge of individual patient tumor immune responses will enable medical community to treat cancer patients more precisely. In this regard, OV seems to be a part of multimodality cancer treatment option in the near future. In this chapter, the fundamental characteristics and mechanism of actions of oncolytic viruses are initially described and then overview of the important clinical trials of various oncolytic viruses for a number of cancers is presented.

Characterization of rotavirus strains isolated from children with acute gastroenteritis in Rawalpindi, Pakistan.

Diarrhea is the leading cause of childhood morbidity and mortality particularly in developing countries and rotavirus has been identified as the major pathogen associated with diarrheal infections. This study was conducted to detect genotypic distribution of predominant rotavirus strains circulating in children suffering from acute gastroenteritis in Rawalpindi, Pakistan. Stool specimens were collected from children ≤5 years of age, visiting Military Hospital, Rawalpindi, with signs and symptoms of acute gastroenteritis. Two hundred and eighty-four specimens were collected during the period from April 2017 to March 2018. Enzyme immunoassay was performed for detection of rotavirus and reverse transcription-PCR (RT-PCR) was carried out for amplification of VP7 and VP4 gene segments followed by multiplex PCR using genotype-specific primers. Out of 284 children, 71 were found rotavirus positive and among them, 54% were females and 46% males. Our findings showed 92% of infection among children ≤2 years of age, while, the peak age of rotavirus incidence was found to be 6-12 months. Although, rotavirus infection was observed throughout the year but frequency increased in winter. Subtype G1P[8] was more prevalent followed by G2P[4], G3P[8], and G4P[6] subtypes. The results of this study provide insight into the disease burden as well as information on rotavirus diversity which will be useful to develop future strategies to control and prevent diarrheal infections among children.

Climate beast: a potential threat for repercussions of disease status in Pakistan.

Pakistan is amongst the developing countries, which have been strongly affected by several emerging and re-emerging disease outbreaks as a consequence of climate change. Various studies have clearly demonstrated the impact of climate change on human health in Pakistan. This has increased the rate of morbidity and mortality, related not only to vector-borne, water-borne and food-borne diseases but has also contributed to the prevalence of neurological, cardiovascular and respiratory disorders. It is therefore important to take adequate measurements for water management and improve sanitary conditions especially in case of natural disasters. In order to effectively control the emerging and re-emerging infections in the country, an early, more Rigorous response is required, by the national health department, to monitor and evaluate the spread of infections in future. Therefore, precise planning and management strategies should be defined in order to circumvent the damage caused by the natural disasters associated with climate changes. This mini-review gives an overview about the public health issues associated with environmental change with special reference to Pakistan. This will provide a baseline for policymakers to develop public health surveillance programs in Pakistan.

Development of robust in vitro RNA-dependent RNA polymerase assay as a possible platform for antiviral drug testing against dengue.

NS5 is the largest and most conserved protein among the four dengue virus (DENV) serotypes. It has been the target of interest for antiviral drug development due to its major role in replication. NS5 consists of two domains, the N-terminal methyltransferase domain and C-terminal catalytic RNA-dependent RNA polymerase (RdRp) domain. It is an unstable protein and is prone to inactivation upon prolonged incubation at room temperature, thus affecting the inhibitor screening assays. In the current study, we expressed and purified DENV RdRp alone in Esherichia coli (E. coli) cells. The N-terminally His-tagged construct of DENV RdRp was transformed into E. coli expression strain BL-21 (DE3) pLysS cells. Protein expression was induced with isopropyl-ß-D-thiogalactopyranoside (IPTG) at a final concentration of 0.4mM. The induced cultures were then grown for 20h at 18°C and cells were harvested by centrifugation at 6000xg for 15min at 4°C. The recombinant protein was purified using HisTrap affinity column (Ni-NTA) and then the sample was subjected to size exclusion chromatography, which successfully removed the degradation product obtained during the previous purification step. The in vitro polymerase activity of RdRp was successfully demonstrated using homopolymeric polycytidylic acid (poly(rC)) RNA template. This study describes the high level production of enzymatically active DENV RdRp protein which can be used to develop assays for testing large number of compounds in a high-throughput manner. RdRp has the de novo initiation activity and the in vitro polymerase assays for the protein provide a platform for highly robust and efficient antiviral compound screening systems.

In Vitro Antiviral Activity of Cinnamomum cassia and Its Nanoparticles Against H7N3 Influenza A Virus.

Nanoparticles have wide-scale applications in various areas, including medicine, chemistry, electronics, and energy generation. Several physical, biological, and chemical methods have been used for synthesis of silver nanoparticles. Green synthesis of silver nanoparticles using plants provide advantages over other methods as it is easy, efficient, and eco-friendly. Nanoparticles have been extensively studied as potential antimicrobials to target pathogenic and multidrug-resistant microorganisms. Their applications recently extended to development of antivirals to inhibit viral infections. In this study, we synthesized silver nanoparticles using Cinnamomum cassia (Cinnamon) and evaluated their activity against highly pathogenic avian influenza virus subtype H7N3. The synthesized nanoparticles were characterized using UVVis absorption spectroscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. Cinnamon bark extract and its nanoparticles were tested against H7N3 influenza A virus in Vero cells and the viability of cells was determined by tetrazolium dye (MTT) assay. The silver nanoparticles derived from Cinnamon extract enhanced the antiviral activity and were found to be effective in both treatments, when incubated with the virus prior to infection and introduced to cells after infection. In order to establish the safety profile, Cinnamon and its corresponding nanoparticles were tested for their cytotoxic effects in Vero cells. The tested concentrations of extract and nanoparticles (up to 500 µg/ml) were found non-toxic to Vero cells. The biosynthesized nanoparticles may, hence, be a promising approach to provide treatment against influenza virus infections.