Role of herpes simplex virus 1 protein ICP47 in antigen presentation and pathogenesis

The herpes simplex virus (HSV) immunomodulatory protein, ICP47, conceals infected cells from CD8+ T cells by inhibiting the presentation of peptides on MHC class I. The mechanism by which ICP47 exerts this function is by binding to the transporter associated with antigen processing (TAP) protein, blocking peptide transport and loading onto MHC I molecules in the ER. The earliest studies of ICP47 supported by biochemical and in vitro observations noted marked species specificity with human but not mouse TAP being inhibited by this protein. However, later work demonstrated that ICP47 can contribute to HSV neurovirulence in mice. The discordance between biochemical and in vivo data leaves our understanding of ICP47 and its role in evading CD8+ T cells incomplete. Data from our laboratory suggested that ICP47 is likely to be expressed during the establishment and maintenance of HSV-1 latency, however, its exact function during these stages of infection is unknown. Therefore, in this study, we sought to re-visit the discrepancies discussed above and investigate the role of ICP47 during HSV-1 infection. We utilised different strains of HSV and mice, as well as an alternate infection model and unique methods to quantify the effect of ICP47 on levels of antigen presentation. In our mouse model, where HSV is confined to the peripheral nervous system, deletion of ICP47 from HSV-1 KOS did not alter lesion development, virus load, spread or reactivation. Likewise, latency was unaffected by ICP47 deficiency as determined using a sensitive Cre-marking mouse model. Further observations from the Cre-marking mouse model revealed that unlike the ICP47 promoter inserted in an ectopic locus, native promoters did not induce additional neuronal marking by Cre beyond lytic infection. We evaluated the reasons behind the difference in marking using newly generated recombinant viruses. Subsequent flank infection of ROSA26R mice with these viruses showed that the local genomic context is also important for regulation of gene expression. By contrast to our in vivo pathogenesis data, we were able to show that ICP47 does inhibit antigen presentation significantly on HSV-infected mouse cells using in vitro antigen presentation assays. However, in mouse cells, antigen presentation was ablated by 44%, compared to an 85% reduction in human cells. As CD8+ T cells have been shown to recognize very few peptide-MHC I complexes on the surface of target cells, it is important to consider the efficiency at which ICP47 inhibits human and mouse TAP. Therefore, we used mass spectrometry to identify and quantify MHC I bound peptides derived from HSV-1 during viral infection. We found that more peptide sequences were presented on mouse cells infected with ICP47 null virus compared to those infected with wild-type virus. We quantified the presentation of 14 of these peptides and the contribution of ICP47 to this process in human and mouse cells. We found that ICP47 almost entirely blocks human TAP-mediated peptide presentation, though the degree of inhibition was somewhat peptide-specific. Conversely, the effect of ICP47 on mouse TAP was far less profound, resulting in only up to five-fold reduction in MHC-peptide abundance. In conclusion, this study shows that despite significant inhibition of antigen presentation in mouse cells, ICP47 may not be an effective immune modulator in mice and suggests a need for re-evaluation of suitable mouse models

Wound healing activity of methanolic extract of Turbinella pyrum from Gulf of Mannar, India

Molluscs are a promising source of bioactive substances and are virtually untapped resources of novel compounds. Many novel metabolites with potent pharmacological properties have been discovered in marine organisms in recent years. The present study aimed to investigate the wound healing activity of a methanolic extract of the marine gastropod Turbinella pyrum using an excision and incision wound model. To determine the minimum lethal dose, acute oral toxicity studies were performed as per the Organization for Economic Co-operation and Development (OECD) guidelines. Excision and incision wound models were used to evaluate the wound healing activity of the methanolic extract of T. pyrum by preparing a simple ointment base BP at different concentrations using five groups of Wistar albino rats. Group I (control) received a topical application of the simple ointment BP. Group II (Standard) was treated with topical application of 5% framycetin sulphate cream, and Groups III, IV and V were treated with 5%, 10% and 15% methanolic extracts of T. pyrum. Student's t test was used to analyse the results obtained from the present study, and P<0.05 was considered significant. In the incision wound model, the epithelialization period was also found to be highly significant (P<0.05) in group V (10.77%) when compared to the standard (12.69%). In the excision wound model, the epithelialization period was also found to be highly significant (P<0.05) in group IV (13.17%) and group V (11.38%) when compared to that of the standard (Group II) (14.56%).This finding justifies that the methanolic extract of T. pyrum has properties that render it capable of promoting accelerated wound-healing activity.

A STUDY ON THE FACTORS THAT IMPACT THE FUTURE TRENDS OF MARKETING: EVIDENCE FROM THE HOSPITALITY INDUSTRY IN KLANG VALLEY, MALAYSIA

The hospitality industry has been impacted by the Covid-19 Pandemic and is still ravaging several nations. Therefore, changing the normality of business operations and activities, especially in marketing trends, is crucial. This research evaluates the factors that impact future marketing trends, focusing on the employees in the hospitality industry within Klang Valley, Malaysia. In this research, the independent variables (impact of the post-Covid-19 Pandemic, transition process from traditional to digital marketing methods, consumers’ reactions towards digital marketing, and possibility of leveraging Industry 4.0) and their relationship to the dependent variable (future trends of marketing in the hospitality industry) were studied. Surveys via Google Forms were disseminated to employees in the hospitality industry within the Klang Valley. The data collected from 390 respondents from the hospitality industry contributed to this research by determining the correlated factors which shaped the future trends and practices in marketing. These factors were supported by the analysis modules and the underpinning theory developed by previous researchers. Based on the response, female respondents have responded more than male respondents, with the Malay ethnic group being the majority. Subsequently, most respondents have attained a bachelor’s degree and worked in the industry as junior executives for nearly 15 years. This study has proven that the transition process from traditional to digital marketing methods, consumers’ reaction, and the possibility of leveraging industry 4.0 has a significant relationship with future marketing trends. In conclusion, this research shows that technology transformation and consumer-centric methods can significantly change the landscape of marketing for the hospitality industry in the future.  Article visualizations

Growth, Surface Morphology and Mechanical Properties of Potassium Hydrogen Sulphate Single Crystals for Antimicrobial and Third-Order NLO Applications

A good quality single crystal of potassium hydrogen sulphate (KHS) has been grown and subjected to characterization techniques including single crystal X-ray diffraction, scanning electron microscope, hardness test, Z-scan and antimicrobial test. The single crystal X-ray diffraction study discloses the orthorhombic system of the KHS crystals. The SEM analysis shows the formation of tiny hillocks in the KHS crystal. Vickers microhardness test was utilized for testing the mechanical hardness of the grown KHS crystals. Moreover, the mechanical parameters such as elastic stiffness constant and yield strength were also determined. The nonlinear optical properties such as nonlinear susceptibility, nonlinear refractive index, and nonlinear absorption coefficient were estimated by Z scan analysis. In addition, antimicrobial activity was performed against certain pathogens for medication applications

Cytotoxic activity of crude and partially purified ink of L.duvauceli towards HepG2cell line

ABSTRACT The present study aims to evaluate the anticancer activity of the crude and partially purified protein fractionated ink of Loligo duvauceli on the Hep G2 cell line using cell viability and cell proliferation assay (MTT assay). Different concentrations of the ink were prepared (125µg, 250µg, 500µg) and the cytotoxic activity was determined. Among the three doses tested, the crude ink of L.duvauceli at the concentration of 500 µg/ml was found to inhibit the viability of the cell effectively and the percentage of viability ranged between 33 -41. Cells viability decreased with increasing concentrations of the samples. HepG2 cells treated with protein fractionated ink, decreased the percentage of viability and the percentage ranged from 30-49. MTT assay revealed that partially purified ink of L. duvauceli showed higher activity than that of crude ink. The percentage of cell death was 70 in partially purified protein fractionated ink and 67% in crude ink at a concentration of 500µg. IC 50 value was obtained at a concentration of 125µg. The present findings suggest the profound anticarcinogenic activity of partially purified ink of L.duvauceli on HepG2 cancer cell line. Further purified compounds can be used as a potential chemotherapeutic drug for the treatment of Hepatic cancer

Breaking the Camel's Back: Can Cognitive Overload be Quantified in the Human Brain?

Reductionism lies at the heart of science, yet this pre-occupation with the trees may mean that cognitive science is missing the forest. Based on the assumption that individual cognitive and perceptual processes interact to form bottle-necks of processing, which, in turn, have measurable detrimental effects on human performance, whole-head continuous EEG was recorded as participants undertook baseline, mild cognitive load and heavy cognitive load tasks. Behavioral measures (reaction times and error rates) showed significant performance decrements between the mild and heavy cognitive load conditions. Graph analysis and pattern identification was then used to identify a sub-set of cortical locations reflecting significant, measurable neural differences between the mild and heavy cognitive load states. This thus lays the foundation for future research into suitable metrics for more accurately measuring degree of global cognitive load as well as practical applications such as developing simple devices for measuring cognitive load in real time

Multi-targeted loss of the antigen presentation molecule MR1 during HSV-1 and HSV-2 infection

Summary: The major histocompatibility complex (MHC), Class-I-related (MR1) molecule presents microbiome-synthesized metabolites to Mucosal-associated invariant T (MAIT) cells, present at sites of herpes simplex virus (HSV) infection. During HSV type 1 (HSV-1) infection there is a profound and rapid loss of MR1, in part due to expression of unique short 3 protein. Here we show that virion host shutoff RNase protein downregulates MR1 protein, through loss of MR1 transcripts. Furthermore, a third viral protein, infected cell protein 22, also downregulates MR1, but not classical MHC-I molecules. This occurs early in the MR1 trafficking pathway through proteasomal degradation. Finally, HSV-2 infection results in the loss of MR1 transcripts, and intracellular and surface MR1 protein, comparable to that seen during HSV-1 infection. Thus HSV coordinates a multifaceted attack on the MR1 antigen presentation pathway, potentially protecting infected cells from MAIT cell T cell receptor-mediated detection at sites of primary infection and reactivation

Neuroprotective effect of tocotrienol-rich fraction and a-tocopherol of vitamin E against glutamate toxicity in neuronal cells and astrocytes

Vitamin E is a fat-soluble antioxidant consisting of tocopherol and tocotrienol. The tocotrienol-rich fraction (TRF) palm oil extract comprises 25% α-tocopherol (α- TCP) and 75% tocotrienols. TRF has been shown to possess potent antioxidant, antiinflammatory,anti-cancer, neuroprotective, and cholesterol-lowering activities. Glutamate is the main excitatory amino acid neurotransmitter in mammalian central nervous systems; it can be excitotoxic and has been suggested to play a key role in neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease. In this study, the effects of vitamin E when supplemented before (pre-treatment) and after (post-treatment) glutamate insult were elucidated in neuronal and astrocyte cell lines. The neuroprotective effect of TRF and α-TCP were investigated. Glutamatemediated cytotoxicity was diminished by pre- and post-treatment of TRF and α-TCP.Vitamin E acted as a potent antioxidant agent in recovering mitochondrial injury from elevated oxidative stress, and cells exhibited better survival following glutamate toxicity. Quantitative morphological studies were also conducted via an apoptosis detection kit using flow cytometric analysis. Pre- and post-treatment with TRF and α-TCP led to better survival and lower cell death rates following glutamate neurotoxicity. The flow cytometry morphological findings were validated by scanning electron microscopy analysis. Cell cycle analysis was also performed using an RNAse-propidium iodide assay. The presence of glutamate in the nerve cells caused DNA or protein damage and chromatin destruction; manipulating these nerve cells to re-enter the cell cycle promoted repair of the damage. Supplementation of TRF and α-TCP enhanced the DNA repair process, with higher numbers of nerve cells accumulating in the S and G2/M phases, indicating active replication and repair of the DNA damage that had occurred during the previous cell cycle. In both TRF and α-TCP pre- and post-treatment groups, glutamate-injured cells exhibited significant reductions in concentrations of the lipid peroxidation biomarker malondialdehyde. Ferric reducing antioxidant power (FRAP) assay was employed to determine the total antioxidant power in the cells. There was significantly increased antioxidant capacity in the cells treated with TRF or α-TCP as compared to glutamate-treated cells, which indicated good neuroprotection. Exposure to glutamate also reduced the concentrations of glutathione, superoxide dismutase, and catalase, important natural antioxidants synthesized in neurons and astrocytes. Both pre- and post-treatment of vitamin E markedly increased antioxidant activity. Subsequently, the expression of traumatic brain injury markers for neuron-specific enolase (NSE) and S100 calcium-binding protein B (S100 β) were elucidated using real-time PCR. The results revealed the downregulation of NSE and S100B upon glutamate challenge in neuronal cells and astrocytes following treatment with different concentrations of TRF and α-TCP, a sign of the recovery process. Human apoptosis quantitative PCR array analysis determined that post-treatment with 200 ng/mL TRF and α-TCP upregulated the anti-apoptotic genes and downregulated the pro-apoptotic genes in both the neuronal and astrocyte cell lines. In conclusion, TRF and α-TCP have protective and recovery properties against glutamate toxicity in neuronal cells and astrocytes. From the average value calculation, TRF preceded α-TCP in neuroprotection against glutamate insult in both astrocytes and neuronal cells. Hence, the present study can serve as a platform for further studies on the effects of TRF and α-TCP, as they could be developed into potential treatment agents for neurodegenerative diseases