Crosstalk between the Intestinal Virome and Other Components of the Microbiota, and Its Effect on Intestinal Mucosal Response and Diseases.

In recent years, there has been ample evidence illustrating the effect of microbiota on gut immunity, homeostasis, and disease. Most of these studies have engaged more efforts in understanding the role of the bacteriome in gut mucosal immunity and disease. However, studies on the virome and its influence on gut mucosal immunity and pathology are still at infancy owing to limited metagenomic tools. Nonetheless, the existing studies on the virome have largely been focused on the bacteriophages as these represent the main component of the virome with little information on endogenous retroviruses (ERVs) and eukaryotic viruses. In this review, we describe the gut virome, and its role in gut mucosal response and disease progression. We also explore the crosstalk between the virome and other microorganisms in the gut mucosa and elaborate on how these interactions shape the gut mucosal immunity going from bacteriophages through ERVs to eukaryotic viruses. Finally, we elucidate the potential contribution of this crosstalk in the pathogenesis of inflammatory bowel diseases and colon cancer.

The Relevance of Bioinformatics Applications in the Discovery of Vaccine Candidates and Potential Drugs for COVID-19 Treatment.

The application of bioinformatics to vaccine research and drug discovery has never been so essential in the fight against infectious diseases. The greatest combat of the 21st century against a debilitating disease agent SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) virus discovered in Wuhan, China, December 2019, has piqued an unprecedented usage of bioinformatics tools in deciphering the molecular characterizations of infectious pathogens. With the viral genome data of SARS-COV-2 been made available barely weeks after the reported outbreak, bioinformatics platforms have become an all-time critical tool to gain time in the fight against the disease pandemic. Before the outbreak, different platforms have been developed to explore antigenic epitopes, predict peptide-protein docking and antibody structures, and simulate antigen-antibody reactions and lots more. However, the advent of the pandemic witnessed an upsurge in the application of these pipelines with the development of newer ones such as the Coronavirus Explorer in the development of efficacious vaccines, drug repurposing, and/or discovery. In this review, we have explored the various pipelines available for use, their relevance, and limitations in the timely development of useful therapeutic candidates from genomic data knowledge to clinical therapy.

Immuno-informatics design of a multimeric epitope peptide based vaccine targeting SARS-CoV-2 spike glycoprotein.

Developing an efficacious vaccine for SARS-CoV-2 infection is critical to stemming COVID-19 fatalities and providing the global community with immune protection. We have used a bioinformatic approach to aid in designing an epitope peptide-based vaccine against the spike protein of the virus. Five antigenic B cell epitopes with viable antigenicity and a total of 27 discontinuous B cell epitopes were mapped out structurally in the spike protein for antibody recognition. We identified eight CD8+ T cell 9-mers and 12 CD4+ T cell 14-15-mer as promising candidate epitopes putatively restricted by a large number of MHC I and II alleles, respectively. We used this information to construct an in silico chimeric peptide vaccine whose translational rate was highly expressed when cloned in pET28a (+) vector. With our In silico test, the vaccine construct was predicted to elicit high antigenicity and cell-mediated immunity when given as a homologous prime-boost, triggering of toll-like receptor 5 by the adjuvant linker. The vaccine was also characterized by an increase in IgM and IgG and an array of Th1 and Th2 cytokines. Upon in silico challenge with SARS-CoV-2, there was a decrease in antigen levels using our immune simulations. We, therefore, propose that potential vaccine designs consider this approach.

Haematological changes associated with Newcastle disease vaccination in chickens using gums from Cedrela odorata and Khaya senegalensis as delivery agents.

Our previous ex-vivo and in vivo investigations have established immunopotentiating property of Khaya senegalensis and Cedrela odorata gums; however the safety of the use of this gum combination in chicken has not been described. Hence this study evaluates the haematological profile of chickens vaccinated with Newcastle disease vaccine delivered through the oral and ocular routes using gums from Cedrela odorata and Khaya senegalensis as delivery agents. 252 one-day old chickens were grouped gum-vaccine oral (GVOR), vaccine oral (VOR), gum-vaccine ocular (GVOC), vaccine ocular (VOC), gum oral (GOR), gum ocular (GOC), no-gum-no-vaccine but challenged (NGNV/C), no-gum-no-vaccine unchallenged (NGNV/U). They were vaccinated on days 21 and 42 and challenged day 84. Blood samples were collected before first vaccination and at selected intervals afterwards. Analysis was done using one way ANOVA with P<0.05 considered significant. Packed cell volume, total white cell count, heterocyte-lymphocyte ratios and platelet count varied insignificantly (P>0.05) throughout the period of observation across groups with no observable derangements. Hence, the absence of derangement in haematological indices from this study suggests that the dilution rate recommended from the ex-vivo study is safe for administration of Newcastle disease vaccine in chickens irrespective of the routes of delivery.

Humoral and mucosal immune responses in challenged chickens vaccinated with Infectious bursal disease vaccine using gums from Cedrela odorata and Khaya senegalensis as delivery agents.

The emergence of antigenic variants and very virulent strains of infectious bursa disease virus (IBDV) in vaccinated flocks considerably stimulated research in IBDV vaccine administration. The mucoadhesive and immunopotentials of Cedrela odorata and Khaya senegalensis were explored in vaccine delivery against clinical IBDV in broiler chickens. A total of 400 chicks were successfully brooded and raised from day old for commencement of this experiment. The birds were randomly distributed into eight groups with an average of 50 birds per group comprising: Gums-Gumboro Vaccine Ocular (infected) (GGVOC), Gumboro Vaccine alone Ocular (infected) (GVOC), Gums alone Ocular (infected) (GOC), Gums-Gumboro Vaccine Oral (infected) (GGVOR), Gumboro Vaccine alone Oral (infected) (GVOR), Gums alone Oral (infected) (GOR), No-Vaccine-No-Gums (infected) (NVNG/i), and No-Vaccine-No-Gums (not infected) (NVNG). On a weekly basis, 1.5mls of blood were collected from 5 birds and 3 birds euthanized per group for serological analysis and mucosal washings (trachea and intestine) respectively. Data obtained were analyzed and sample to positive ratio calculated. The post 1st vaccination trachea IgG antibody response was moderately higher in the ocular groups than the oral groups. It was also high in the VOC, GVOC, GOC, VOR groups than the GVOR groups. The antibody response (IgG) pre and post 1st vaccination, post 2nd vaccination and post infection from serum, trachea and intestinal washes showed that by week 1 Post 1st vaccination, there was insignificant increase in titer serum response of the gum-vaccine ocular group compared to the vaccine ocular alone while both groups were insignificantly higher than the oral group. Overall, serum titer showed a rapid response with spiked significant response by 48h pi in the gum vaccine groups (especially GVOR), which peaks by day 3 and remains insignificantly higher throughout the day 7 pi compared to vaccine alone groups. In conclusion, use of the mucilage from C. odorata and K. senegalenses in equal proportion has given better enhancement of the response to IBDV vaccination and premise for further investigations for improvement against IBD.

Histomorphometry and Protein Expression From the Ovary and Uterine Horns of Wistar Strain Albino Rats Treated with Methanol Leave Extract of Parquetina Nigrescens.

BACKGROUND: The effects of methanol extract of Parquetina nigrescens were studied on histomorphometry and protein expression (SDS-PAGE) from the ovaries and uteri of wistar rats. METHODS: 30 sexually matured rats were used for the study with 10 each in the control and treatment 100 mgkg-1 and 400 mgkg-1 groups. The extract was orally administered for 14 days. Histological sections of tissues collected presented no abnormalities. RESULTS: An increase in the number of developing and matured follicles were observed during the study in the treated groups compared to the control in the follicular and the luteal phases. The corpora lutea in the treated groups were fewer in number to that of the control in the follicular phase and in the luteal phase. Sections of the uterine horns showed significant narrowing in the lumen diameter and increases in epithelial height with increased laydown of the lamina propria in the treated groups. The expression of protein bands fractionated during the study, confirm the presence of proteins expressed repeatedly from the ovary and uterine horns in the follicular and luteal phases at the 70 kDa and 63 kDa regions. CONCLUSIONS: The study concluded that the methanol extract of the plant increased folliculogenesis on the ovary, secretory activity in the nuclei of the epithelium and the fibroplasia of the lamina propria while narrowing the lumen of the uterine horns which are similar to the effects of oestrogen or oestrogen-like substances on these reproductive organs and may have an effect on the abundance of protein expressed in the follicular phase.

Clinicopathological evaluation of Newcastle disease virus vaccination using gums from Cedrela odorata and Khaya senegalensis as delivery agents in challenged chickens.

Following previous studies on delivery potential and immune response of chickens given Newcastle disease vaccine with gums, this study was conducted to evaluate the protective ability of vaccines delivered with plant gums against clinicopathological features of Newcastle disease (ND). Processed gums from incised trunks of Cedrela odorata and Khaya senegalensis trees were combined with ND vaccine in ratio 2:2:1 and administered at 21 days to white leghorn cockerels after weaning of maternal antibodies. The birds were grouped into gum-vaccine-oral (GVOR), vaccine-oral (VOR), gum-vaccine-ocular (GVOC), vaccine-ocular (VOC), gum-oral (GOR), gum-ocular (GOC), no-gum-no-vaccine/challenged (NGNV/C), no-gum-no-vaccine/unchallenged (NGNV/U). Vaccination was boosted with the same preparation at day 42 while birds were challenged with live ND virus (KUDU strain) at day 84. Clinical signs (Dullness, Diarrhoea, Paralysis, Torticollis) Post infection (Pi), terminal weakness, gross and histology lesions were scored on a severity scale from absent (0-), mild (1+) to moderate (2+) and severe (3+). Scores were assigned a quantitative score of 0, 10, 20, 30 respectively. Clinical signs scores for the 5 week Pi were subjected to Friedman test to assess the significance of severity among the groups. The test was significant at 1% significance level which implies that the clinical signs ranked highest in the NGNV/C, followed by the Gum alone groups, the vaccine alone groups and the gum-vaccine groups irrespective of route. Moribund birds subsequently euthanized were seen in the GOR and GOC group at 21% each and at 57% in NGNV/C group alone. No signs were seen in the NVNG/U group. Grossly, mild to moderate lesions were seen in all groups except GVOR and NGNV/U. At histology, pulmonary congestion, acute pneumonia, cecal tonsilar haemorrhages, gliosis and neuronophagia were present at different proportions in all groups except the GVOR and NGNV/U. Overall, lesion severity was least in the gum-vaccine groups while the oral groups had less lesion score compared to the ocular. From this study, phytogenic mucoadhesives polymers used hold immense potential as a delivery agent capable of improving protection against clinicopathologic features of Newcastle disease in previously vaccinated birds.

Ex-vivo evaluation of the mucoadhesive properties of Cedrela odorata and Khaya senegalensis gums with possible applications for veterinary vaccine delivery.

BACKGROUND: Few studies have investigated the interaction of bioadhesives with biologic tissues for veterinary application. Hence, this study evaluates the mucoadhesive property and vaccine delivery properties of polymers from phytogenic origin. Gums from Cedrela odorata and Khaya senegalensis were harvested, purified, dried and compressed into 500 mg tablets individually and in combined ratios. The time taken for these tablets, placed on freshly excised (5 × 5 cm) trachea and duodenal tissues of cattle, chicken, pig, sheep and goat and fastened to the basket end of a tablet dissolution machine probe set at 50 rev/min in a phosphate buffer 6.8 pH at 37 °C, to fall off the tissue was the peak adhesion time (PAT). Gum with best PAT was combined with Newcastle disease vaccine and the procedure repeated. Haemagglutination assay (HA) was conducted on the gum polymer-vaccine mix with gum and vaccine individually as controls. RESULTS: On intestinal and trachea tissues, Cedrela gum polymer averagely had prolonged PAT (≈1 h 30 min and 1 h respectively) while average PAT values of Khaya gums followed the same trend but too transient PAT (≈6 and 0.3 min respectively). However on combination, Cedrela-Khaya polymer mix (1:1) was best on chicken, cattle and sheep trachea and intestinal tissues (PAT of 1 h 30 min and 2 h 24 min respectively). On combination with vaccine, the PAT of the gums reduced slightly on cattle and sheep tissues while other animal tissue showed varied results. The HA results showed the gum polymer boosted the HA property of the vaccine (Log 10(5)), when compared to vaccine alone (Log 10(4)). CONCLUSION: Hence, mucoadhesives from phytogenic sources have potential for non-invasive vaccine application.