Helminth-derived proteins as immune system regulators: a systematic review of their promise in alleviating colitis

Helminth-derived proteins have immunomodulatory properties, influencing the host's immune response as an adaptive strategy for helminth survival. Helminth-derived proteins modulate the immune response by inducing anti-inflammatory cytokines, promoting regulatory T-cell development, and ultimately favouring a Th2-biased immune response. This systematic review focused on helminth-derived proteins and explored their impact on reducing inflammatory responses in mouse models of colitis. A systematic search across Medline, EMBASE, Web of Science, and Cochrane Library identified fourteen relevant studies. These studies reported immunomodulatory changes, including increased production of anti-inflammatory cells and cytokines. In mouse models of colitis treated with on helminth-derived proteins, significant improvements in pathological parameters such as body weight, colon length, and microscopic inflammatory scores were observed compared to control groups. Moreover, helminth-derived proteins can enhance the function of Tregs and alleviate the severity of inflammatory conditions. The findings underscore the pivotal role of helminth-derived proteins in immunomodulation, specifically in the axis of cytokine secretion and immune cell polarization. The findings offer new opportunities for treating chronic inflammatory conditions such Crohn's disease.

Redefining the battle against colorectal cancer: a comprehensive review of emerging immunotherapies and their clinical efficacy

Colorectal cancer (CRC) is the third most common cancer globally and presents a significant challenge owing to its high mortality rate and the limitations of traditional treatment options such as surgery, radiotherapy, and chemotherapy. While these treatments are foundational, they are often poorly effective owing to tumor resistance. Immunotherapy is a groundbreaking alternative that has recently emerged and offers new hope for success by exploiting the body's own immune system. This article aims to provide an extensive review of clinical trials evaluating the efficacy of various immunotherapies, including CRC vaccines, chimeric antigen receptor T-cell therapies, and immune checkpoint inhibitors. We also discuss combining CRC vaccines with monoclonal antibodies, delve into preclinical studies of novel cancer vaccines, and assess the impact of these treatment methods on patient outcomes. This review seeks to provide a deeper understanding of the current state of CRC treatment by evaluating innovative treatments and their potential to redefine the prognosis of patients with CRC.

Extracellular matrix detached cancer cells resist oxidative stress by increasing histone demethylase KDM6 activity

Epithelial cancer cells rely on the extracellular matrix (ECM) attachment in order to spread to other organs. Detachment from the ECM is necessary for these cells to seed in other locations. When the attachment to the ECM is lost, cellular metabolism undergoes a significant shift from oxidative metabolism to glycolysis. Additionally, the cancer cells become more dependent on glutaminolysis to avoid a specific type of cell death known as anoikis, which is associated with ECM detachment. In our recent study, we observed increased expression of H3K27me3 demethylases, specifically KDM6A/B, in cancer cells that were resistant to anoikis. Since KDM6A/B is known to regulate cellular metabolism, we investigated the effects of suppressing KDM6A/B with GSK-J4 on the metabolic processes in these anoikis-resistant cancer cells. Our results from untargeted metabolomics revealed a profound impact of KDM6A/B inhibition on various metabolic pathways, including glycolysis, methyl histidine, spermine, and glutamate metabolism. Inhibition of KDM6A/B led to elevated reactive oxygen species (ROS) levels and depolarization of mitochondria, while reducing the levels of glutathione, an important antioxidant, by diminishing the intermediates of the glutamate pathway. Glutamate is crucial for maintaining a pool of reduced glutathione. Furthermore, we discovered that KDM6A/B regulates the key glycolytic genes expression like hexokinase, lactate dehydrogenase, and GLUT-1, which are essential for sustaining glycolysis in anoikis-resistant cancer cells. Overall, our findings demonstrated the critical role of KDM6A/B in maintaining glycolysis, glutamate metabolism, and glutathione levels. Inhibition of KDM6A/B disrupts these metabolic processes, leading to increased ROS levels and triggering cell death in anoikis-resistant cancer cells.

ACE2-Fc and DPP4-Fc decoy receptors against SARS-CoV-2 and MERS-CoV variants: a quick therapeutic option for current and future coronaviruses outbreaks

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and the Middle East respiratory syndrome coronavirus (MERS-CoV) are highly pathogenic human coronaviruses (CoVs). Anti-CoVs mAbs and vaccines may be effective, but the emergence of neutralization escape variants is inevitable. Angiotensin-converting enzyme 2 and dipeptidyl peptidase 4 enzyme are the getaway receptors for SARS-CoV-2 and MERS-CoV, respectively. Thus, we reformatted these receptors as Fc-fusion decoy receptors. Then, we tested them in parallel with anti-SARS-CoV (ab1-IgG) and anti-MERS-CoV (M336-IgG) mAbs against several variants using pseudovirus neutralization assay. The generated Fc-based decoy receptors exhibited a strong inhibitory effect against all pseudotyped CoVs. Results showed that although mAbs can be effective antiviral drugs, they might rapidly lose their efficacy against highly mutated viruses. We suggest that receptor traps can be engineered as Fc-fusion proteins for highly mutating viruses with known entry receptors, for a faster and effective therapeutic response even against virus harboring antibodies escape mutations.

Robust memory humoral immune response to SARS-CoV-2 in the tonsils of adults and children

Background

Adaptive humoral immunity against SARS-CoV-2 has mainly been evaluated in peripheral blood. Human secondary lymphoid tissues (such as tonsils) contain large numbers of plasma cells that secrete immunoglobulins at mucosal sites. Yet, the role of mucosal memory immunity induced by vaccines or natural infection against SARS-CoV-2 and its variants is not fully understood.

Methods

Tonsillar mononuclear cells (TMNCs) from adults (n=10) and children (n=11) were isolated and stimulated using positive SARS-CoV-2 nasal swabs. We used endpoint enzyme-linked immunosorbent assays (ELISAs) for the measurement of anti-S1, -RBD, and -N IgG antibody levels and a pseudovirus microneutralization assay to assess neutralizing antibodies (nAbs) in paired serum and supernatants from stimulated TMNCs.

Results

Strong systemic humoral response in previously SARS-CoV-2 infected and vaccinated adults and children was observed in accordance with the reported history of the participants. Interestingly, we found a significant increase in anti-RBD IgG (305 and 834 folds) and anti-S1 IgG (475 and 443 folds) in the stimulated TMNCs from adults and children, respectively, compared to unstimulated cells. Consistently, the stimulated TMNCs secreted higher levels of nAbs against the ancestral Wuhan strain and the Omicron BA.1 variant compared to unstimulated cells by several folds. This increase was seen in all participants including children with no known history of infection, suggesting that these participants might have been previously exposed to SARS-CoV-2 and that not all asymptomatic cases necessarily could be detected by serum antibodies. Furthermore, nAb levels against both strains were significantly correlated in adults (r=0.8788; p = 0.0008) and children (r = 0.7521; p = 0.0076), and they strongly correlated with S1 and RBD-specific IgG antibodies.

Conclusion

Our results provide evidence for persistent mucosal humoral memory in tonsils from previously infected and/or vaccinated adults and children against recent and old variants upon re-exposure. They also highlight the importance of targeting mucosal sites with vaccines to help control infection at the primary sites and prevent potential breakthrough infections.

Seroprevalence of Toscana and sandfly fever Sicilian viruses in humans and livestock animals from western Saudi Arabia

High seroprevalence rates of several phleboviruses have been reported in domestic animals and humans in sandfly-infested regions. Sandfly Fever Sicilian virus (SFSV) and Toscana virus (TOSV) are two of these viruses commonly transmitted by Phlebotomus sandflies. While SFSV can cause rapidly resolving mild febrile illness, TOSV could involve the central nervous system (CNS), causing diseases ranging from aseptic meningitis to meningoencephalitis. Sandfly-associated phleboviruses have not been investigated before in Saudi Arabia and are potential causes of infection given the prevalence of sandflies in the country. Here, we investigated the seroprevalence of SFSV and TOSV in the western region of Saudi Arabia in samples collected from blood donors, livestock animals, and animal handlers. An overall seroprevalence of 9.4% and 0.8% was found in humans for SFSV and TOSV, respectively. Seropositivity was significantly higher in non-Saudis compared to Saudis and increased significantly with age especially for SFSV. The highest seropositivity rate was among samples collected from animal handlers. Specifically, in blood donors, 6.4% and 0.7% tested positive for SFSV and TOSV nAbs, respectively. Animal handlers showed higher seroprevalence rates of 16% and 1% for anti-SFSV and anti-TOSV nAbs, respectively, suggesting that contact with livestock animals could be a risk factor. Indeed, sera from livestock animals showed seropositivity of 53.3% and 4.4% in cows, 27.5% and 7.8% in sheep, 2.2% and 0.0% in goats, and 10.0% and 2.3% in camels for SFSV and TOSV, respectively. Together, these results suggest that both SFSV and TOSV are circulating in the western region of Saudi Arabia in humans and livestock animals, albeit at different rates, and that age and contact with livestock animals could represent risk factors for infection with these viruses.

Bivalent vaccines effectively protect mice against influenza A and respiratory syncytial viruses

Influenza and Respiratory Syncytial virus (RSV) infections together contribute significantly to the burden of acute lower respiratory tract infections. Despite the disease burden, no approved RSV vaccine is available. While approved vaccines are available for influenza, seasonal vaccination is required to maintain protection. In addition to both being respiratory viruses, they follow a common seasonality, which warrants the necessity for a concerted vaccination approach. Here, we designed bivalent vaccines by utilizing highly conserved sequences, targeting both influenza A and RSV, as either a chimeric antigen or individual antigens separated by a ribosome skipping sequence. These vaccines were found to be effective in protecting the animals from challenge by either virus, with mechanisms of protection being substantially interrogated in this communication.

Impact of the SARS-CoV-2 nucleocapsid 203K/204R mutations on the inflammatory immune response in COVID-19 severity

BACKGROUND

The excessive inflammatory responses provoked by SARS-CoV-2 infection are critical factors affecting the severity and mortality of COVID-19. Previous work found that two adjacent co-occurring mutations R203K and G204R (KR) on the nucleocapsid (N) protein correlate with increased disease severity in COVID-19 patients. However, links with the host immune response remain unclear.

METHODS

Here, we grouped nasopharyngeal swab samples of COVID-19 patients into two cohorts based on the presence and absence of SARS-CoV-2 nucleocapsid KR mutations. We performed nasopharyngeal transcriptome analysis of age, gender, and ethnicity-matched COVID-19 patients infected with either SARS-CoV-2 with KR mutations in the N protein (KR patients n = 39) or with the wild-type N protein (RG patients n = 39) and compared to healthy controls (n = 34). The impact of KR mutation on immune response was further characterized experimentally by transcriptomic and proteomic profiling of virus-like-particle (VLP) incubated cells.

RESULTS

We observed markedly elevated expression of proinflammatory cytokines, chemokines, and interferon-stimulated (ISGs) genes in the KR patients compared to RG patients. Using nasopharyngeal transcriptome data, we found significantly higher levels of neutrophils and neutrophil-to-lymphocyte (NLR) ratio in KR patients than in the RG patients. Furthermore, transcriptomic and proteomic profiling of VLP incubated cells confirmed a similar hyper-inflammatory response mediated by the KR variant.

CONCLUSIONS

Our data demonstrate an unforeseen connection between nucleocapsid KR mutations and augmented inflammatory immune response in severe COVID-19 patients. These findings provide insights into how mutations in SARS-CoV-2 modulate host immune output and pathogenesis and may contribute to more efficient therapeutics and vaccine development.

Identification of novel interacts partners of ADAR1 enzyme mediating the oncogenic process in aggressive breast cancer

Triple-negative breast cancer (TNBC) subtype is characterized by aggressive clinical behavior and poor prognosis patient outcomes. Here, we show that ADAR1 is more abundantly expressed in infiltrating breast cancer (BC) tumors than in benign tumors. Further, ADAR1 protein expression is higher in aggressive BC cells (MDA-MB-231). Moreover, we identify a novel interacting partners proteins list with ADAR1 in MDA-MB-231, using immunoprecipitation assay and mass spectrometry. Using iLoop, a protein-protein interaction prediction server based on structural features, five proteins with high iloop scores were discovered: Histone H2A.V, Kynureninase (KYNU), 40S ribosomal protein SA, Complement C4-A, and Nebulin (ranged between 0.6 and 0.8). In silico analysis showed that invasive ductal carcinomas had the highest level of KYNU gene expression than the other classifications (p < 0.0001). Moreover, KYNU mRNA expression was shown to be considerably higher in TNBC patients (p < 0.0001) and associated with poor patient outcomes with a high-risk value. Importantly, we found an interaction between ADAR1 and KYNU in the more aggressive BC cells. Altogether, these results propose a new ADAR-KYNU interaction as potential therapeutic targeted therapy in aggressive BC.

Construction of VSVΔ51M oncolytic virus expressing human interleukin-12

The use of oncolytic viruses (OVs) in combination with cytokines, such as IL-12, is a promising approach for cancer treatment that addresses the limitations of current standard treatments and traditional cancer immunotherapies. IL-12, a proinflammatory cytokine, triggers intracellular signaling pathways that lead to increased apoptosis of tumor cells and enhanced antitumor activity of immune cells via IFN-γ induction, making this cytokine a promising candidate for cancer therapy. Targeted expression of IL-12 within tumors has been shown to play a crucial role in tumor eradication. The recent development of oncolytic viruses enables targeted delivery and expression of IL-12 at the tumor site, thereby addressing the systemic toxicities associated with traditional cancer therapy. In this study, we constructed an oncolytic virus, VSVΔ51M, based on the commercially available VSV wild-type backbone and further modified it to express human IL-12. Our preclinical data confirmed the safety and limited toxicity of the modified virus, VSV-Δ51M-hIL-12, supporting its potential use for clinical development.

Phage cocktails - an emerging approach for the control of bacterial infection with major emphasis on foodborne pathogens

Phage therapy has recently attracted a great deal of attention to counteract the rapid emergence of antibiotic-resistant bacteria. In comparison to monophage therapy, phage cocktails are typically used to treat individual and/or multi-bacterial infections since the bacterial agents are unlikely to become resistant as a result of exposure to multiple phages simultaneously. The bacteriolytic effect of phage cocktails may produce efficient killing effect in comparison to individual phage. However, multiple use of phages (complex cocktails) may lead to undesirable side effects such as dysbiosis, horizontal gene transfer, phage resistance, cross resistance, and/or higher cost of production. Cocktail formulation, therefore, representa compromise between limiting the complexity of the cocktail and achieving substantial bacterial load reduction towards the targeted host organisms. Despite some constraints, the applications of monophage therapy have been well documented in the literature. However, phage cocktails-based approaches and their role for the control of pathogens have not been well investigated. In this review, we discuss the principle of phage cocktail formulations, their optimization strategies, major phage cocktail preparations, and their efficacy in inactivating various food borne bacterial pathogens.

Livelihood activities, human mobility, and risk of malaria infection in elimination settings: a case-control study

BACKGROUND

Livelihood activities and human movements participate in the epidemiology of vector-borne diseases and influence malaria risk in elimination settings. In Saudi Arabia, where malaria transmission intensity varies geographically, it is vital to understand the components driving transmission within specific areas. In addition, shared social, behavioural, and occupational characteristics within communities may provoke the risk of malaria infection. This study aims to understand the relationship between human mobility, livelihood activities, and the risk of malaria infection in the border region of Jazan to facilitate further strategic malaria interventions. In addition, the study will complement and reinforce the existing efforts to eliminate malaria on the Saudi and Yemen border by providing a deeper understanding of human movement and livelihood activities.

METHODS

An unmatched case-control study was conducted. A total of 261 participants were recruited for the study, including 81 cases of confirmed malaria through rapid diagnostic tests (RDTs) and microscopy and 180 controls in the Baish Governorate in Jazan Provinces, Saudi Arabia. Individuals who received malaria tests were interviewed regarding their livelihood activities and recent movement (travel history). A questionnaire was administered, and the data was captured electronically. STATA software version 16 was used to analyse the data. Bivariate and multivariate analyses were conducted to determine if engaging in agricultural activities such as farming and animal husbandry, recent travel history outside of the home village within the last 30 days and participating in spiritual gatherings were related to malaria infection status.

RESULTS

A logistical regression model was used to investigate components associated with malaria infection. After adjusting several confounding factors, individuals who reported travelling away from their home village in the last 30 days OR 11.5 (95% CI 4.43-29.9), and those who attended a seasonal night spiritual gathering OR 3.04 (95% CI 1.10-8.42), involved in animal husbandry OR 2.52 (95% CI 1.10-5.82), and identified as male OR 4.57 (95% CI 1.43-14.7), were more likely to test positive for malaria infection.

CONCLUSION

Human movement and livelihood activities, especially at nighttime, should be considered malaria risk factors in malaria elimination settings, mainly when the targeted area is limited to a confined borderland area.

Combined effect of ipilimumab and nivolumab improves oncology endpoints in metastatic melanoma patients

Metastatic melanoma has less frequency, but considered as the most dreaded cancer. The combination of nivolumab & ipilimumab is proving their mettle in treating metastatic melanoma. The patients when administered with the combination of nivolumab & ipilimumab have shown improved median progression free survival, objective response rate and overall survival rate compared with nivolumab and ipilimumab monotherapy. The combination shrinks the tumor cells by attacking different checkpoints viz. CTLA-4 and PD-L1, respectively. The combination treatment reveals reduced disease progression and suggests nivolumab's non-cross resistant nature. The median progression free survival in "nivolumab plus ipilimumab" group has shown an increase of 66.7% and 296.6% in comparison to nivolumab and ipilimumab monotherapy. The other parameter viz. objective response rate improvement is equivalent to almost 14% and 38.6% when compared to nivolumab and ipilimumab monotherapy, respectively.

The importance of combining serological testing with RT-PCR assays for efficient detection of COVID-19 and higher diagnostic accuracy

Misdiagnosing suspected COVID-19 individuals could largely contribute to the viruses transmission, therefore, making an accurate diagnosis of infected subjects vital in minimizing and containing the disease. Although RT-PCR is the standard method in detecting COVID-19, it is associated with some limitations, including possible false negative results. Therefore, serological testing has been suggested as a complement assay to RT-PCR to support the diagnosis of acute infections. In this study, 15 out of 639 unvaccinated healthcare workers (HCWs) were tested negative for COVID-19 by RT-PCR and were found seropositive for SARS-CoV-2 nucleocapsid protein-specific IgM and IgG antibodies. These participants underwent additional confirmatory RT-PCR and SARS-CoV-2 spike-specific ELISA tests. Of the 15 individuals, nine participants were found negative by second RT-PCR but seropositive for anti-spike IgM and IgG antibodies and neutralizing antibodies confirming their acute infection. At the time of collection, these nine individuals were in close contact with COVID-19-confirmed patients, with 77.7% reporting COVID-19-related symptoms. These results indicate that including serological tests in the current testing profile can provide better outcomes and help contain the spread of the virus by increasing diagnostic accuracy to prevent future outbreaks rapidly.

Mouth rinses efficacy on salivary SARS-CoV-2 viral load: A randomized clinical trial

Considering the global trend to confine the COVID-19 pandemic by applying various preventive health measures, preprocedural mouth rinsing has been proposed to mitigate the transmission risk of SARS-CoV-2 in dental clinics. The study aimed to investigate the effect of different mouth rinses on salivary viral load in COVID-19 patients. This study was a single-center, randomized, double-blind, six-parallel-group, placebo-controlled clinical trial that investigated the effect of four mouth rinses (1% povidone-iodine, 1.5% hydrogen peroxide, 0.075% cetylpyridinium chloride, and 80 ppm hypochlorous acid) on salivary SARS-CoV-2 viral load relative to the distilled water and no-rinse control groups. The viral load was measured by quantitative reverse transcription PCR (RT-qPCR) at baseline and 5, 30, and 60 min post rinsing. The viral load pattern within each mouth rinse group showed a reduction overtime; however, this reduction was only statistically significant in the hydrogen peroxide group. Further, a significant reduction in the viral load was observed between povidone-iodine, hydrogen peroxide, and cetylpyridinium chloride compared to the no-rinse group at 60 min, indicating their late antiviral potential. Interestingly, a similar statistically significant reduction was also observed in the distilled water control group compared to the no-rinse group at 60 min, proposing mechanical washing of the viral particles through the rinsing procedure. Therefore, results suggest using preprocedural mouth rinses, particularly hydrogen peroxide, as a risk-mitigation step before dental procedures, along with strict adherence to other infection control measures.

Exploring the role of Nrf2 signaling in glioblastoma multiforme

Glioblastoma multiforme (GBM) is one of the most aggressive glial cell tumors in adults. Although current treatment options for GBM offer some therapeutic benefit, median survival remains poor and does not generally exceed 14 months. Several genes, such as isocitrate dehydrogenase (IDH) enzyme and O6-methylguanine-DNA methyltransferase (MGMT), have been implicated in pathogenesis of the disease. Treatment is often adapted based on the presence of IDH mutations and MGMT promoter methylation status. Recent GBM cell line studies have associated Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) expression with high-grade tumors. Increased Nrf2 expression is often found in tumors with IDH-1 mutations. Nrf2 is an important transcription factor with anti-apoptotic, antioxidative, anti-inflammatory, and proliferative properties due to its complex interactions with multiple regulatory pathways. In addition, evidence suggests that Nrf2 promotes  GBM cell survival in hypoxic environment,by up-regulating hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF). Downregulation of Nrf2 has been shown to improve GBM sensitivity to chemotherapy drugs such as Temozolomide. Thus, Nrf2 could be a key regulator of GBM pathways and potential therapeutic target.  Further research efforts exploring an interplay between Nrf2 and major molecular signaling mechanisms could offer novel GBM drug candidates with a potential to significantly improve patients prognosis.

Bacterial co-infections and antimicrobial resistance associated with the Coronavirus Disease 2019 infection

Bacterial co-infections are typically associated with viral respiratory tract infections and pose a significant public health problem around the world. COVID-19 infection damages tissues lining the respiratory track and regulates immune cells/cytokines leading to microbiome dysbiosis and facilitating the area to be colonized by pathogenic bacterial agents. There have been reports of different types of bacterial co-infection in COVID-19 patients. Some of these reports showed despite geographical differences and differences in hospital settings, bacterial co-infections are a major cause of morbidity and mortality in COVID-19 patients. The inappropriate use of antibiotics for bacterial infections, particularly broad-spectrum antibiotics, can also further complicate the infection process, often leading to multi drug resistance, clinical deterioration, poor prognosis, and eventually death. To this end, researchers must establish a new therapeutic approach to control SARS-CoV-2 and the associated microbial coinfections. Hence, the aim of this review is to highlight the bacterial co-infection that has been recorded in COVID-19 patients and the status of antimicrobial resistance associated with the dual infections.

Clinical relevance of biomarkers, new therapeutic approaches, and role of post-translational modifications in the pathogenesis of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder that causes progressive loss of cognitive functions like thinking, memory, reasoning, behavioral abilities, and social skills thus affecting the ability of a person to perform normal daily functions independently. There is no definitive cure for this disease, and treatment options available for the management of the disease are not very effective as well. Based on histopathology, AD is characterized by the accumulation of insoluble deposits of amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs). Although several molecular events contribute to the formation of these insoluble deposits, the aberrant post-translational modifications (PTMs) of AD-related proteins (like APP, Aβ, tau, and BACE1) are also known to be involved in the onset and progression of this disease. However, early diagnosis of the disease as well as the development of effective therapeutic approaches is impeded by lack of proper clinical biomarkers. In this review, we summarized the current status and clinical relevance of biomarkers from cerebrospinal fluid (CSF), blood and extracellular vesicles involved in onset and progression of AD. Moreover, we highlight the effects of several PTMs on the AD-related proteins, and provide an insight how these modifications impact the structure and function of proteins leading to AD pathology. Finally, for disease-modifying therapeutics, novel approaches, and targets are discussed for the successful treatment and management of AD.

Interrelation between extracellular vesicles miRNAs with chronic lung diseases

Extracellular vehicles (EVs) are nanoscale lipid bilayer vesicles that carry biologically active biomolecule cargos like proteins, lipids, and nucleic acids (DNA, RNA) outside of the cell. Blood (serum/plasma), urine, and bronchoalveolar lavage fluid are all examples of biofluids from which they may be collected. EVs play a vital role in intracellular communication. The molecular signature of EVs largely depends on the parental cell's status. EVs are classified into two groups, (1) exosomes (originated by endogenous route) and (2) microvesicles (originated from the plasma membrane, also known as ectosomes). The quantity and types of EV cargo vary during normal conditions compared to pathological conditions (chronic inflammatory lung diseases or lung cancer). Consequently, EVs contain novel biomarkers that differ based on the cell type of origin and during lung diseases. Small RNAs (e.g., microRNAs) are transported by EVs, which is one of the most rapidly evolving research areas in the field of EVs biology. EV-mediated cargos transport small RNAs that can result in reprograming the target/recipient cells. Multiple chronic inflammatory lung illnesses, such as chronic obstructive pulmonary disease, asthma, pulmonary hypertension, pulmonary fibrosis, cystic fibrosis, acute lung injury, and lung cancer, have been demonstrated to be regulated by EV. In this review, we will consolidate the current knowledge and literature on the novel role of EVs and their small RNAs concerning chronic lung diseases (CLDs). Additionally, we will also provide better insight into the clinical and translational impact of mesenchymal stem cells-derived EVs as novel therapeutic agents in treating CLDs.

Apigenin Loaded Lipoid-PLGA-TPGS Nanoparticles for Colon Cancer Therapy: Characterization, Sustained Release, Cytotoxicity, and Apoptosis Pathways

Colon cancer (CC) is one of major causes of mortality and affects the socio-economic status world-wide. Therefore, developing a novel and efficient delivery system is needed for CC management. Thus, in the present study, lipid polymer hybrid nanoparticles of apigenin (LPHyNPs) was prepared and characterized on various parameters such as particle size (234.80 ± 12.28 nm), PDI (0.11 ± 0.04), zeta potential (−5.15 ± 0.70 mV), EE (55.18 ± 3.61%), etc. Additionally, the DSC, XRD, and FT-IR analysis determined drug entrapment and affinity with the selected excipient, demonstrating a promising drug affinity with the lipid polymer. Morphological analysis via SEM and TEM exhibited spherical NPs with a dark color core, which indicated drug entrapment inside the core. In vitro release study showed significant (p < 0.05) sustained release of AGN from LPHyNPs than AGN suspension. Further, the therapeutic efficacy in terms of apoptosis and cell cycle arrest of developed LPHyNPs against CC was estimated by performing flow cytometry and comparing its effectiveness with blank LPHyNPs and AGN suspension, which exhibited remarkable outcomes in favor of LPHyNPs. Moreover, the mechanism behind the anticancer attribute was further explored by estimating gene expression of various signaling molecules such as Bcl-2, BAX, NF-κB, and mTOR that were involved in carcinogenic pathways, which indicated significant (p < 0.05) results for LPHyNPs. Moreover, to strengthen the anticancer potential of LPHyNPs against chemoresistance, the expression of JNK and MDR-1 genes was estimated. Outcomes showed that their expression level reduced appreciably when compared to blank LPHyNPs and AGN suspension. Hence, it can be concluded that developed LPHyNPs could be an efficient therapeutic system for managing CC.

Identification of 11-Hydroxytephrosin and Torosaflavone A as Potential Inhibitors of 3-Phosphoinositide-Dependent Protein Kinase 1 (PDPK1): Toward Anticancer Drug Discovery

The 3-phosphoinositide-dependent protein kinase 1 (PDPK1) has a significant role in cancer progression and metastasis as well as other inflammatory disorders, and has been proposed as a promising therapeutic target for several malignancies. In this work, we conducted a systematic virtual screening of natural compounds from the IMPPAT database to identify possible PDPK1 inhibitors. Primarily, the Lipinski rules, ADMET, and PAINS filter were applied and then the binding affinities, docking scores, and selectivity were carried out to find effective hits against PDPK1. Finally, we identified two natural compounds, 11-Hydroxytephrosin and Torosaflavone A, bearing substantial affinity with PDPK1. Both compounds showed drug-likeness as predicted by the ADMET analysis and their physicochemical parameters. These compounds preferentially bind to the ATP-binding pocket of PDPK1 and interact with functionally significant residues. The conformational dynamics and complex stability of PDPK1 with the selected compounds were then studied using interaction analysis and molecular dynamics (MD) simulations for 100 ns. The simulation results revealed that PDPK1 forms stable docked complexes with the elucidated compounds. The findings show that the newly discovered 11-Hydroxytephrosin and Torosaflavone A bind to PDPK1 in an ATP-competitive manner, suggesting that they could one day be used as therapeutic scaffolds against PDPK1-associated diseases including cancer.

Immunogenicity of High-Dose MVA-Based MERS Vaccine Candidate in Mice and Camels

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic pathogen that can transmit from dromedary camels to humans, causing severe pneumonia, with a 35% mortality rate. Vaccine candidates have been developed and tested in mice, camels, and humans. Previously, we developed a vaccine based on the modified vaccinia virus Ankara (MVA) viral vector, encoding a full-length spike protein of MERS-CoV, MVA-MERS. Here, we report the immunogenicity of high-dose MVA-MERS in prime–boost vaccinations in mice and camels. Methods: Three groups of mice were immunised with MVA wild-type (MVA-wt) and MVA-MERS (MVA-wt/MVA-MERS), MVA-MERS/MVA-wt, or MVA-MERS/MVA-MERS. Camels were immunised with two doses of PBS, MVA-wt, or MVA-MERS. Antibody (Ab) responses were evaluated using ELISA and MERS pseudovirus neutralisation assays. Results: Two high doses of MVA-MERS induced strong Ab responses in both mice and camels, including neutralising antibodies. Anti-MVA Ab responses did not affect the immune responses to the vaccine antigen (MERS-CoV spike). Conclusions: MVA-MERS vaccine, administered in a homologous prime–boost regimen, induced high levels of neutralising anti-MERS-CoV antibodies in mice and camels. This could be considered for further development and evaluation as a dromedary vaccine to reduce MERS-CoV transmission to humans.

Where do T cell subsets stand in SARS-CoV-2 infection: an update

An outbreak of coronavirus disease 2019 (COVID-19) emerged in China in December 2019 and spread so rapidly all around the globe. It’s continued and spreading more dangerously in India and Brazil with higher mortality rate. Understanding of the pathophysiology of COVID-19 depends on unraveling of interactional mechanism of SARS-CoV-2 and human immune response. The immune response is a complex process, which can be better understood by understanding the immunological response and pathological mechanisms of COVID-19, which will provide new treatments, increase treatment efficacy, and decrease mortality associated with the disease. In this review we present a amalgamate viewpoint based on the current available knowledge on COVID-19 which includes entry of the virus and multiplication of virus, its pathological effects on the cellular level, immunological reaction, systemic and organ presentation. T cells play a crucial role in controlling and clearing viral infections. Several studies have now shown that the severity of the COVID-19 disease is inversely correlated with the magnitude of the T cell response. Understanding SARS-CoV-2 T cell responses is of high interest because T cells are attractive vaccine targets and could help reduce COVID-19 severity. Even though there is a significant amount of literature regarding SARS-CoV-2, there are still very few studies focused on understanding the T cell response to this novel virus. Nevertheless, a majority of these studies focused on peripheral blood CD4+ and CD8+ T cells that were specific for viruses. The focus of this review is on different subtypes of T cell responses in COVID-19 patients, Th17, follicular helper T (TFH), regulatory T (Treg) cells, and less classical, invariant T cell populations, such as δγ T cells and mucosal-associated invariant T (MAIT) cells etc that could influence disease outcome.

Amplifying Lateral Flow Assay Signals for Rapid Detection of COVID-19 Specific Antibodies

Rapid lateral flow immune-assays are point-of-care diagnostic tools that are easy to use, cheap, and do not need centralized infrastructure. Therefore, these devices are appealing for rapid detection of the humoral immune responses to infections, particularly severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel technique introduced here uses a complex of anti-SARS-CoV-2 N-protein antibodies conjugated to gold nanoparticles that are bound to five SARS-CoV-2 N protein conjugated to gold nanoparticles to amplify the signals obtained from the conjugated SARS-CoV-2 N protein and to enhance the assay detection limit. To validate the performance of the adopted lateral flow, serum from SARS-CoV-2 seropositive individuals and prepandamic negative samples are tested and compared to a validated enzyme-linked immunosorbent assay (ELISA) for the detection of SARS-CoV-2 N protein specific IgG and IgM antibodies. The data shows that the designed lateral flow assay has an excellent sensitivity and specificity upon detecting IgM and IgG antibodies by applying only 2 µL from the serum sample to the adopted strips. Taken together, the developed lateral flow immunoassay assay provides a rapid, specific, and highly sensitive means to detect the immune responses against SARS-CoV-2 with only 2 µL from the serum sample.

Persistence of Anti-SARS-CoV-2 Spike IgG Antibodies Following COVID-19 Vaccines

Purpose

This study was conducted to investigate antibody immune responses induced by BNT162b2 and AZD1222 human COVID-19 vaccines in Riyadh city, Saudi Arabia.

Patients and Methods

ELISA was used to evaluate antibodies, against the SARS-CoV-2 spike S1 protein, in serum samples from 432 vaccinated individuals at six time points: pre-vaccination (baseline), post-prime, post-boost, 6-months, and 1 year post-vaccination, and 3 weeks post a third dose. Virus microneutralization assay was used to confirm antibody responses in a subset of samples.

Results

Anti-SARS-CoV-2 spike IgG were detected in most subjects post-prime, reached a peak level post-boost, and remained at high level at the 6-month follow-up. At 1 year post-vaccine, the antibody levels were low but increased to a significant level higher than the peak following a third dose. The third dose was given at an average of 250 days after the second dose. The virus microneutralization assay confirmed the neutralization activity of the induced SARS-CoV-2 IgG antibodies. The vaccines induced higher IgG titres at post-prime (p=0.0001) and 6 months (p=0.006) in previously infected individuals. An increased interval between prime and boost, more than recommended time, appeared to enhance the IgG levels (p=0004). Moreover, the vaccines induced higher IgG levels in younger subjects (p=0.01).

Conclusion

These data provide insights and build on the current understanding of immune responses induced by these two vaccines; and support a third boosting dose for these COVID-19 vaccines.

Universal antibody targeting the highly conserved fusion peptide provides cross-protection in mice

Influenza is a major public health concern causing millions of hospitalizations every year. The current vaccines need annual updating based on prediction of likely strains in the upcoming season. However, mismatches between vaccines and the actual circulating viruses can occur, reducing vaccine effectiveness significantly because of the remarkably high rate of mutation in the viral glycoprotein, hemagglutinin (HA). Clearly, it would be of great interest to determine the potential role of universally conserved epitopes in inducing protective immunity. Here, an antibody against the 14-aa fusion peptide sequence at the N-terminus of the HA2 subunit (Uni-1) was investigated for its ability to elicit antibody-dependent cellular cytotoxicity (ADCC) in vitro and cross-protection against lethal infection in animals. Uni-1, known to neutralize influenza type A (IAV) in vitro, was found to induce strong ADCC against diverse influenza viruses, including human and avian IAVs and both lineages of type B (IBV). The ADCC effects against human IAVs by Uni-1 was comparable to ADCC induced by well-characterized antibodies, F10 and FI6V3. Importantly, mice treated with Uni-1 were protected against lethal challenge of IAV and IBV. These results revealed the versatile effector functions of this universal antibody against markedly diverse strains of both IAV and IBV.

The fusion peptide is the only universally conserved epitope in both IAV and IBV

Mono-specific universal antibody induces strong ADCC against human and avian IAV

Mono-specific universal antibody induces strong ADCC against IBV from both genetic lineages of IBV

The antibody has bi-functional effector functions against several influenza viruses

Middle East Respiratory Syndrome Coronavirus Infection Elicits Long-lasting Specific Antibody, T and B Cell Immune Responses in Recovered Individuals

BACKGROUND

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a highly pathogenic zoonotic betacoronavirus and a global public health concern. Better undersetting of the immune responses to MERS-CoV is needed to characterize the correlates of protection and durability of the immunity and to aid in developing preventative and therapeutic interventions. Although MERS-CoV-specific circulating antibodies could persist for several years post-recovery, their waning raises concerns about their durability and role in protection. Nonetheless, memory B and T cells could provide long-lasting protective immunity despite the serum antibodies levels.

METHODS

Serological and flow cytometric analysis of MERS-CoV-specific immune responses were performed on samples collected from a cohort of recovered individuals who required intensive care unit (ICU) admission as well as hospital or home isolation several years after infection to characterize the longevity and quality of humoral and cellular immune responses.

RESULTS

Our data showed that MERS-CoV infection could elicit robust long-lasting virus-specific binding and neutralizing antibodies as well as T- and B-cell responses up to 6.9 years postinfection regardless of disease severity or need for ICU admission. Apart from the persistent high antibody titers, this response was characterized by B-cell subsets with antibody-independent functions as demonstrated by their ability to produce tumor necrosis factor α (TNF-α), interleukin (IL)-6, and interferon γ (IFN-γ) cytokines in response to antigen stimulation. Furthermore, virus-specific activation of memory CD8+ and CD4+ T cell subsets from MERS-recovered patients resulted in secretion of high levels of TNF-α, IL-17, and IFN-γ.

CONCLUSIONS

MERS-CoV infection could elicit robust long-lasting virus-specific humoral and cellular responses.

Seroprevalence of COVID-19 in Riyadh City during the early increase of COVID-19 infections in Saudi Arabia, June 2020

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) emerged in December 2019 and caused a global pandemic of the Coronavirus Disease 2019 (COVID-19). More than 170 million cases have been reported worldwide with mortality rate of 1–3%. The detection of SARS-CoV-2 by molecular testing is limited to acute infections, therefore serological studies provide a better estimation of the virus spread in a population. This study aims to evaluate the seroprevalence of SARS-CoV-2 in the major city of Riyadh, Saudi Arabia during the sharp increase of the pandemic, in June 2020. Serum samples from non-COVID patients (n = 432), patients visiting hospitals for other complications and confirmed negative for COVID-19, and healthy blood donors (n = 350) were collected and evaluated using an in-house enzyme-linked immunosorbent assay (ELISA). The overall percentage of positive samples was 7.80% in the combined two populations (n = 782). The seroprevalence was lower in the blood donors (6%) than non-COVID-19 patients (9.25%), p = 0.0004. This seroprevalence rate is higher than the documented cases, indicating asymptomatic or mild unreported COVID-19 infections in these two populations. This warrants further national sero-surveys and highlights the importance of real-time serological surveillance during pandemics.

SARS-CoV-2 genomes from Saudi Arabia implicate nucleocapsid mutations in host response and increased viral load

Monitoring SARS-CoV-2 spread and evolution through genome sequencing is essential in handling the COVID-19 pandemic. Here, we sequenced 892 SARS-CoV-2 genomes collected from patients in Saudi Arabia from March to August 2020. We show that two consecutive mutations (R203K/G204R) in the nucleocapsid (N) protein are associated with higher viral loads in COVID-19 patients. Our comparative biochemical analysis reveals that the mutant N protein displays enhanced viral RNA binding and differential interaction with key host proteins. We found increased interaction of GSK3A kinase simultaneously with hyper-phosphorylation of the adjacent serine site (S206) in the mutant N protein. Furthermore, the host cell transcriptome analysis suggests that the mutant N protein produces dysregulated interferon response genes. Here, we provide crucial information in linking the R203K/G204R mutations in the N protein to modulations of host-virus interactions and underline the potential of the nucleocapsid protein as a drug target during infection.

DNA Based Vaccine Expressing SARS-CoV-2 Spike-CD40L Fusion Protein Confers Protection Against Challenge in a Syrian Hamster Model

SARS-CoV-2 infections present a tremendous threat to public health. Safe and efficacious vaccines are the most effective means in preventing the infections. A variety of vaccines have demonstrated excellent efficacy and safety around the globe. Yet, development of alternative forms of vaccines remains beneficial, particularly those with simpler production processes, less stringent storage conditions, and the capability of being used in heterologous prime/boost regimens which have shown improved efficacy against many diseases. Here we reported a novel DNA vaccine comprised of the SARS-CoV-2 spike protein fused with CD40 ligand (CD40L) serving as both a targeting ligand and molecular adjuvant. A single intramuscular injection in Syrian hamsters induced significant neutralizing antibodies 3-weeks after vaccination, with a boost substantially improving immune responses. Moreover, the vaccine also reduced weight loss and suppressed viral replication in the lungs and nasal turbinates of challenged animals. Finally, the incorporation of CD40L into the DNA vaccine was shown to reduce lung pathology more effectively than the DNA vaccine devoid of CD40L. These results collectively indicate that this DNA vaccine candidate could be further explored because of its efficacy and known safety profile.

David versus goliath: ACE2-Fc receptor traps as potential SARS-CoV-2 inhibitors

Anti-SARS-CoV-2 monoclonal antibodies and vaccines have shown improvement in lowering viral burden and hospitalization. However, emerging SARS-CoV-2 variants contain neutralizing antibody-escape mutations. Therefore, several reports have suggested the administration of recombinant angiotensin-converting enzyme 2 (rACE2) as a soluble receptor trap to block SARS-CoV-2 infection and limit viral escape potential. Several strategies have been implemented to enhance the efficacy of rACE2 as a therapeutic agent. Fc fusions have been used to improve pharmacokinetics and boost the affinity and avidity of ACE2 decoys for the virus spike protein. Furthermore, the intrinsic catalytic activity of ACE2 can be eliminated by introducing point mutations on the catalytic site of ACE2 to obtain an exclusive antiviral activity. This review summarizes different evolution platforms that have been used to enhance ACE2-Fc (i.e., immunoadhesins) as potential therapeutics for the current pandemic or future outbreaks of SARS-associated betacoronaviruses.

Advances in immunotherapy for glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common and aggressive malignant brain tumor of the central nervous system and has a very poor prognosis. The current standard of care for patients with GBM involves surgical resection, radiotherapy, and chemotherapy. Unfortunately, conventional therapies have not resulted in significant improvements in the survival outcomes of patients with GBM; therefore, the overall mortality rate remains high. Immunotherapy is a type of cancer treatment that helps the immune system to fight cancer and has shown success in different types of aggressive cancers. Recently, healthcare providers have been actively investigating various immunotherapeutic approaches to treat GBM. We reviewed the most promising immunotherapy candidates for glioblastoma that have achieved encouraging results in clinical trials, focusing on immune checkpoint inhibitors, oncolytic viruses, nonreplicating viral vectors, and chimeric antigen receptor (CAR) immunotherapies.

Low clinical utility of testing for anti-platelet factor 4 in asymptomatic individuals after ChAdOx1 nCoV-19 vaccine

INTRODUCTION

The development of anti-platelet factor 4 (PF4) antibodies is linked to a rare thrombotic complication described now as vaccine-induced immune thrombotic thrombocytopenia (VITT). This clinical syndrome with thrombosis and thrombocytopenia was reported after exposure to the Oxford-AstraZeneca COVID-19 vaccine, ChAdOx1 nCoV-19 vaccine (AZD1222), and Ad26.COV2.S vaccine (Janssen/Johnson & Johnson). In the absence of the clinical features, the incidence of positive anti-PF4 antibodies in asymptomatic individuals post-vaccination is unclear.

METHODS

The aim of this study was to evaluate the development of anti-PF4 antibodies in asymptomatic individuals 14-21 days after receiving the first dose of ChAdOx1 nCoV-19 vaccine (AZD1222) and BNT162b2 vaccine. Prospectively, we collected serum from individuals before and after ChAdOx1 nCoV-19 vaccine and BNT162b2 vaccine and measured anti-PF4 antibodies using the Asserachrom HPIA IgG ELISA (Stago, Asnieres, France).

RESULTS

We detected positive anti-PF4 antibodies in 5 of 94 asymptomatic individuals post-vaccine with a rate of 5.3% with low titers (OD 0.3-0.7). Four of 5 individuals who tested positive after the vaccine had also positive anti-PF4 antibodies before the vaccine, which indicates that a majority of the positive results are due to preexisting anti-PF4 antibodies. We did not find a relation between the development of anti-PF4 antibodies and the immune response to the vaccine, status of prior COVID-19 infection, and baseline characteristics of participants. None of the participants developed thrombosis nor thrombocytopenia.

CONCLUSION

Our results provide new evidence to guide the diagnostic algorithm of suspected cases of VITT. In the absence of thrombosis and thrombocytopenia, there is a low utility of testing for anti-PF4 antibodies.

Targeted Inhibition of Fibroblast Growth Factor Receptor 1-GLI Through AZD4547 and GANT61 Modulates Breast Cancer Progression

The underlying mechanism of fibroblast growth factor receptor 1 (FGFR1) mediated carcinogenesis is still not fully understood. For instance, FGFR1 upregulation leads to endocrine therapy resistance in breast cancer patients. The current study aimed to identify FGFR1-linked genes to devise improved therapeutic strategies. RNA-seq and microarray expression data of 1,425 breast cancer patients from two independent cohorts were downloaded for the analysis. Gene Set Enrichment Analysis (GSEA) was performed to identify differentially expressed pathways associated with FGFR1 expression. Validation was done using 150 fresh tumor biopsy samples of breast cancer patients. The clinical relevance of mRNA and protein expression of FGFR1 and its associated genes were also evaluated in mouse embryonic fibroblasts (MEFs) and breast cancer cell line (MDA-MB-231). Furthermore, MDA-MB-231 cell line was treated with AZD4547 and GANT61 to identify the probable role of FGFR1 and its associated genes on cells motility and invasion. According to GSEA results, SHH pathway genes were significantly upregulated in FGFR1 patients in both discovery cohorts of breast cancer. Statistical analyses using both discovery cohorts and 150 fresh biopsy samples revealed strong association of FGFR1 and GLI1, a member of SHH pathway. The increase in the expression of these molecules was associated with poor prognosis, lymph node involvement, late stage, and metastasis. Combined exposures to AZD4547 (FGFR1 inhibitor) and GANT61 (GLI1 inhibitor) significantly reduced cell proliferation, cell motility, and invasion, suggesting molecular crosstalk in breast cancer progression and metastasis. A strong positive feedback mechanism between FGFR1-GLI1 axis was observed, which significantly increased cell proliferation and metastasis. Targeting FGFR1-GLI1 simultaneously will significantly improve the prognosis of breast cancer in patients.

Iron Chelation Reduces DNA Damage in Sickle Cell Anemia

Sickle cell anemia (SCA) is a blood condition that causes severe pain. One of the therapeutic agents used for the treatment of SCA is hydroxyurea, which reduces the episodes of pain but causes DNA damage to white blood cells. The aim of this study was to evaluate the efficacy of the combination of hydroxyurea and iron chelation therapy in relation to the extent of DNA-associated damage. Blood samples were collected from 120 subjects from five groups. Various hematological parameters of the obtained serum were analyzed. The amount of damage caused to their DNA was detected using the comet assay and fluorescent microscopy techniques. The percentage of DNA damage in the group that was subjected to the combination therapy (target group) was 1.32% ± 1.51%, which was significantly lower (P < .05) than that observed in the group treated with hydroxyurea alone (6.36% ± 2.36%). While the target group showed comparable levels of hemoglobin F and lactate dehydrogenase compared to the group that was treated with hydroxyurea alone, highly significant levels of transferrin receptors and ferritin were observed in the target group. The results of this study revealed that the administration of iron chelation drugs with hydroxyurea may help improve patients' health and prevent the DNA damage caused to white blood cells due to hydroxyurea. Further studies are needed to better understand the underlying mechanisms that are involved in this process.

Synthetic SARS-CoV-2 Spike-Based DNA Vaccine Elicits Robust and Long-Lasting Th1 Humoral and Cellular Immunity in Mice

The ongoing global pandemic of coronavirus disease 2019 (COVID-19) calls for an urgent development of effective and safe prophylactic and therapeutic measures. The spike (S) glycoprotein of severe acute respiratory syndrome-coronavirus (SARS-CoV-2) is a major immunogenic and protective protein and plays a crucial role in viral pathogenesis. In this study, we successfully constructed a synthetic codon-optimized DNA-based vaccine as a countermeasure against SARS-CoV-2, denoted VIU-1005. The design was based on a codon-optimized coding sequence of a consensus full-length S glycoprotein. The immunogenicity of the vaccine was tested in two mouse models (BALB/c and C57BL/6J). Th1-skewed systemic S-specific IgG antibodies and neutralizing antibodies (nAbs) were significantly induced in both models 4 weeks after three injections with 100 μg of the VIU-1005 vaccine via intramuscular needle injection but not intradermal or subcutaneous routes. Such immunization induced long-lasting IgG and memory T cell responses in mice that lasted for at least 6 months. Interestingly, using a needle-free system, we showed an enhanced immunogenicity of VIU-1005 in which lower or fewer doses were able to elicit significantly high levels of Th1-biased systemic S-specific immune responses, as demonstrated by the significant levels of binding IgG antibodies, nAbs and IFN-γ, TNF and IL-2 cytokine production from memory CD8⁺ and CD4⁺ T cells in BALB/c mice. Furthermore, compared to intradermal needle injection, which failed to induce any significant immune response, intradermal needle-free immunization elicited a robust Th1-biased humoral response similar to that observed with intramuscular immunization. Together, our results demonstrate that the synthetic VIU-1005 candidate DNA vaccine is highly immunogenic and capable of inducing long-lasting Th1-skewed humoral and cellular immunity in mice. Furthermore, we show that the use of a needle-free system could enhance the immunogenicity and minimize doses needed to induce protective immunity in mice, supporting further preclinical and clinical testing of this candidate vaccine.

Cellular and Humoral Immunogenicity of a Candidate DNA Vaccine Expressing SARS-CoV-2 Spike Subunit 1

The urgent need for effective, safe and equitably accessible vaccines to tackle the ongoing spread of COVID-19 led researchers to generate vaccine candidates targeting varieties of immunogens of SARS-CoV-2. Because of its crucial role in mediating binding and entry to host cell and its proven safety profile, the subunit 1 (S1) of the spike protein represents an attractive immunogen for vaccine development. Here, we developed and assessed the immunogenicity of a DNA vaccine encoding the SARS-CoV-2 S1. Following in vitro confirmation and characterization, the humoral and cellular immune responses of our vaccine candidate (pVAX-S1) was evaluated in BALB/c mice using two different doses, 25 µg and 50 µg. Our data showed high levels of SARS-CoV-2 specific IgG and neutralizing antibodies in mice immunized with three doses of pVAX-S1. Analysis of the induced IgG subclasses showed a Th1-polarized immune response, as demonstrated by the significant elevation of spike-specific IgG2a and IgG2b, compared to IgG1. Furthermore, we found that the immunization of mice with three doses of 50 µg of pVAX-S1 could elicit significant memory CD4+ and CD8+ T cell responses. Taken together, our data indicate that pVAX-S1 is immunogenic and safe in mice and is worthy of further preclinical and clinical evaluation.

Seroprevalence of SARS-CoV-2 Binding and Neutralizing Antibodies in Healthcare Workers during the Epidemic Peak in Referral Hospitals and Quarantine Sites: Saudi Arabia

Healthcare workers (HCWs) are at high risk for SARS-CoV-2 infection compared to the general population. Here, we aimed to evaluate and characterize the SARS-CoV-2 seropositivity rate in randomly collected samples among HCWs from the largest referral hospitals and quarantine sites during the peak of the COVID-19 epidemic in the city of Jeddah, the second largest city in Saudi Arabia, using a cross-sectional analytic study design. Out of 693 participants recruited from 29 June to 10 August 2020, 223 (32.2%, 95% CI: 28.8–35.8) were found to be confirmed seropositive for SARS-CoV-2 antibodies, and among those 197 (88.3%) had never been diagnosed with COVID-19. Seropositivity was not significantly associated with participants reporting COVID-19 compatible symptoms as most seropositive HCW participants 140 (62.8%) were asymptomatic. The large proportion of asymptomatic SARS-CoV-2 cases detected in our study demands periodic testing as a general hospital policy.

Simultaneous detection and mutation surveillance of SARS-CoV-2 and multiple respiratory viruses by rapid field-deployable sequencing

BACKGROUND

Strategies for monitoring the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are crucial for combating the pandemic. Detection and mutation surveillance of SARS-CoV-2 and other respiratory viruses require separate and complex workflows that rely on highly specialized facilities, personnel, and reagents. To date, no method can rapidly diagnose multiple viral infections and determine variants in a high-throughput manner.

METHODS

We describe a method for multiplex isothermal amplification-based sequencing and real-time analysis of multiple viral genomes, termed nanopore sequencing of isothermal rapid viral amplification for near real-time analysis (NIRVANA). It can simultaneously detect SARS-CoV-2, influenza A, human adenovirus, and human coronavirus and monitor mutations for up to 96 samples in real time.

FINDINGS

NIRVANA showed high sensitivity and specificity for SARS-CoV-2 in 70 clinical samples with a detection limit of 20 viral RNA copies per μL of extracted nucleic acid. It also detected the influenza A co-infection in two samples. The variant analysis results of SARS-CoV-2-positive samples mirror the epidemiology of coronavirus disease 2019 (COVID-19). Additionally, NIRVANA could simultaneously detect SARS-CoV-2 and pepper mild mottle virus (PMMoV) (an omnipresent virus and water-quality indicator) in municipal wastewater samples.

CONCLUSIONS

NIRVANA provides high-confidence detection of both SARS-CoV-2 and other respiratory viruses and mutation surveillance of SARS-CoV-2 on the fly. We expect it to offer a promising solution for rapid field-deployable detection and mutational surveillance of pandemic viruses.

FUNDING

M.L. is supported by KAUST Office of Sponsored Research (BAS/1/1080-01). This work is supported by KAUST Competitive Research Grant (URF/1/3412-01-01; M.L. and J.C.I.B.) and Universidad Catolica San Antonio de Murcia (J.C.I.B.). A.M.H. is supported by Saudi Ministry of Education (project 436).

Nationwide Seroprevalence of SARS-CoV-2 in Saudi Arabia

BACKGROUND

Estimated seroprevalence of Coronavirus Infectious Disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) is a critical evidence for a better evaluation of the virus spread and monitoring the progress of COVID-19 pandemic in a population. In the Kingdom of Saudi Arabia (KSA), SARS-CoV-2 seroprevalence has been reported in specific regions, but an extensive nationwide study has not been reported. Here, we report a nationwide study to determine the prevalence of SARS-CoV-2 in the population of KSA during the pandemic, using serum samples from healthy blood donors, non-COVID patients and healthcare workers (HCWs) in six different regions of the kingdom, with addition samples from COVID-19 patients.

METHODS

A total of 11,703 serum samples were collected from different regions of the KSA including; 5395 samples from residual healthy blood donors (D); 5877 samples from non-COVID patients collected through residual sera at clinical biochemistry labs from non-COVID patients (P); and 400 samples from consented HCWs. To determine the seroprevalence of SARS-CoV-2, all serum samples, in addition to positive control sera from RT-PCR confirmed COVID-19 patients, were subjected to in-house ELISA with a sample pooling strategy, which was further validated by testing individual samples that make up some of the pools, with a statistical estimation method to report seroprevalence estimates.

RESULTS

Overall (combining D and P groups) seroprevalence estimate was around 11% in Saudi Arabia; and was 5.1% (Riyadh), 1.5% (Jazan), 18.4% (Qassim), 20.8% (Hail), 14.7% (ER; Alahsa), and 18.8% in Makkah. Makkah samples were only D group and had a rate of 24.4% and 12.8% in the cities of Makkah and Jeddah, respectively. The seroprevalence in Saudi Arabia across the sampled areas would be 12 times the reported COVID-19 infection rate. Among HCWs, 7.5% (4.95-10.16 CI 95%) had reactive antibodies to SARS-CoV-2 without reporting any previously confirmed infection. This was higher in HCWs with hypertension. The study also presents the demographics and prevalence of co-morbidities in HCWs and subset of non-COVID-19 population.

INTERPRETATION

Our study estimates the overall national serological prevalence of COVID-19 in Saudi Arabia to be 11%, with an apparent disparity between regions. This indicates the prevalence of asymptomatic or mild unreported COVID-19 cases.

A Robust, Safe, and Scalable Magnetic Nanoparticle Workflow for RNA Extraction of Pathogens from Clinical and Wastewater Samples

Molecular diagnosis and surveillance of pathogens such as SARS-CoV-2 depend on nucleic acid isolation. Pandemics at the scale of COVID-19 can cause a global shortage of proprietary commercial reagents and BSL-2 laboratories to safely perform testing. Therefore, alternative solutions are urgently needed to address these challenges. An open-source method, magnetic-nanoparticle-aided viral RNA isolation from contagious samples (MAVRICS), built upon readily available reagents, and easily assembled in any basically equipped laboratory, is thus developed. The performance of MAVRICS is evaluated using validated pathogen detection assays and real-world and contrived samples. Unlike conventional methods, MAVRICS works directly in samples inactivated in phenol-chloroform (e.g., TRIzol), thus allowing infectious samples to be handled safely without biocontainment facilities. MAVRICS allows wastewater biomass immobilized on membranes to be directly inactivated and lysed in TRIzol followed by RNA extraction by magnetic nanoparticles, thereby greatly reducing biohazard risk and simplifying processing procedures. Using 39 COVID-19 patient samples and two wastewater samples, it is shown that MAVRICS rivals commercial kits in detection of SARS-CoV-2, influenza viruses, and respiratory syncytial virus. Therefore, MAVRICS is safe, fast, and scalable. It is field-deployable with minimal equipment requirements and could become an enabling technology for widespread testing and wastewater monitoring of diverse pathogens.

Quick and Easy Assembly of a One-Step qRT-PCR Kit for COVID-19 Diagnostics Using In-House Enzymes

One-step reverse-transcription quantitative polymerase chain reaction (qRT-PCR) is the most widely applied method for COVID-19 diagnostics. Notwithstanding the facts that one-step qRT-PCR is well suited for the diagnosis of COVID-19 and that there are many commercially available one-step qRT-PCR kits in the market, their high cost and unavailability due to airport closures and shipment restriction became a major bottleneck that had driven the desire to produce the key components of such kits locally. Here, we provide a simple, economical, and powerful one-step qRT-PCR kit based on patent-free, specifically tailored versions of Moloney murine leukemia virus reverse transcriptase and Thermus aquaticus DNA polymerase and termed R3T (Rapid Research Response Team) one-step qRT-PCR. We also demonstrate the robustness of our enzyme production strategies and provide the optimal reaction conditions for their efficient augmentation in a one-step approach. Our kit was routinely able to reliably detect as low as 10 copies of the synthetic RNAs of SARS-CoV-2. More importantly, our kit successfully detected COVID-19 in clinical samples of broad viral titers with similar reliability and selectivity to that of the Invitrogen SuperScript III Platinum One-step qRT-PCR and TaqPath one-step RT-qPCR kits. Overall, our kit has shown robust performance in both laboratory settings and the Saudi Ministry of Health-approved testing facility.

Performance of Commercially Available Rapid Serological Assays for the Detection of SARS-CoV-2 Antibodies

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to spread globally. Although several rapid commercial serological assays have been developed, little is known about their performance and accuracy in detecting SARS-CoV-2-specific antibodies in COVID-19 patient samples. Here, we have evaluated the performance of seven commercially available rapid lateral flow immunoassays (LFIA) obtained from different manufacturers, and compared them to in-house developed and validated ELISA assays for the detection of SARS-CoV-2-specific IgM and IgG antibodies in RT-PCR-confirmed COVID-19 patients. While all evaluated LFIA assays showed high specificity, our data showed a significant variation in sensitivity of these assays, which ranged from 0% to 54% for samples collected early during infection (3–7 days post symptoms onset) and from 54% to 88% for samples collected at later time points during infection (8–27 days post symptoms onset). Therefore, we recommend prior evaluation and validation of these assays before being routinely used to detect IgM and IgG in COVID-19 patients. Moreover, our findings suggest the use of LFIA assays in combination with other standard methods, and not as an alternative.

Early Humoral Response Correlates with Disease Severity and Outcomes in COVID-19 Patients

The Coronavirus Disease 2019 (COVID-19), caused by SARS-CoV-2, continues to spread globally with significantly high morbidity and mortality rates. Antigen-specific responses are of unquestionable value for clinical management of COVID-19 patients. Here, we investigated the kinetics of IgM, IgG against the spike (S) and nucleoproteins (N) proteins and their neutralizing capabilities in hospitalized COVID-19 patients with different disease presentations (i.e., mild, moderate or severe), need for intensive care units (ICU) admission or outcomes (i.e., survival vs death). We show that SARS-CoV-2 specific IgG, IgM and neutralizing antibodies (nAbs) were readily detectable in almost all COVID-19 patients with various clinical presentations. Interestingly, significantly higher levels of nAbs as well as anti-S1 and -N IgG and IgM antibodies were found in patients with more severe symptoms, patients requiring admission to ICU or those with fatal outcomes. More importantly, early after symptoms onset, we found that the levels of anti-N antibodies correlated strongly with disease severity. Collectively, these findings provide new insights into the kinetics of antibody responses in COVID-19 patients with different disease severity.

Early Humoral Response Correlates with Disease Severity and Outcomes in COVID-19 Patients

The Coronavirus Disease 2019 (COVID-19), caused by SARS-CoV-2, continues to spread globally with significantly high morbidity and mortality rates. Antigen-specific responses are of unquestionable value for clinical management of COVID-19 patients. Here, we investigated the kinetics of IgM, IgG against the spike (S) and nucleoproteins (N) proteins and their neutralizing capabilities in hospitalized COVID-19 patients with different disease presentations (i.e., mild, moderate or severe), need for intensive care units (ICU) admission or outcomes (i.e., survival vs death). We show that SARS-CoV-2 specific IgG, IgM and neutralizing antibodies (nAbs) were readily detectable in almost all COVID-19 patients with various clinical presentations. Interestingly, significantly higher levels of nAbs as well as anti-S1 and -N IgG and IgM antibodies were found in patients with more severe symptoms, patients requiring admission to ICU or those with fatal outcomes. More importantly, early after symptoms onset, we found that the levels of anti-N antibodies correlated strongly with disease severity. Collectively, these findings provide new insights into the kinetics of antibody responses in COVID-19 patients with different disease severity.

Seroprevalence of SARS-CoV-2 (COVID-19) among healthcare workers in Saudi Arabia: comparing case and control hospitals

Healthcare workers (HCWs) stand at the frontline for fighting coronavirus disease 2019 (COVID-19) pandemic. This puts them at higher risk of acquiring the infection than other individuals in the community. Defining immunity status among health care workers is therefore of interest since it helps to mitigate the exposure risk. This study was conducted between May 20^th and 30^th, 2020. Eighty-five hospitals across Kingdom of Saudi Arabia were divided into 2 groups: COVID-19 referral hospitals are those to which RT-PCR-confirmed COVID-19 patients were admitted or referred for management (Case-hospitals). COVID-19 nonaffected hospitals where no COVID-19 patients had been admitted or managed and no HCW outbreak (Control hospitals). Next, seroprevalence of severe acute respiratory syndrome coronavirus 2 among HCWs was evaluated; there were 12,621 HCWs from the 85 hospitals. There were 61 case-hospitals with 9379 (74.3%) observations, and 24 control-hospitals with 3242 (25.7%) observations. The overall positivity rate by the immunoassay was 299 (2.36%) with a significant difference between the case-hospital (2.9%) and the control-group (0.8%) (P value <0.001). There was a wide variation in the positivity rate between regions and/or cities in Saudi Arabia, ranging from 0% to 6.31%. Of the serology positive samples, 100 samples were further tested using the SAS2pp neutralization assay; 92 (92%) samples showed neutralization activity.

The seropositivity rate in Kingdom of Saudi Arabia is low and varies across different regions with higher positivity in case-hospitals than control-hospitals. The lack of neutralizing antibodies (NAb) in 8% of the tested samples could mean that assay is a more sensitive assay or that neutralization assay has a lower detection limits; or possibly that some samples had cross-reaction to spike protein of other coronaviruses in the assay, but these were not specific to neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

SARS-CoV-2 S1 and N-based serological assays reveal rapid seroconversion and induction of specific antibody response in COVID-19 patients

As the Coronavirus Disease 2019 (COVID-19), which is caused by the novel SARS-CoV-2, continues to spread rapidly around the world, there is a need for well validated serological assays that allow the detection of viral specific antibody responses in COVID-19 patients or recovered individuals. In this study, we established and used multiple indirect Enzyme Linked Immunosorbent Assay (ELISA)-based serological assays to study the antibody response in COVID-19 patients. In order to validate the assays we determined the cut off values, sensitivity and specificity of the assays using sera collected from pre-pandemic healthy controls, COVID-19 patients at different time points after disease-onset, and seropositive sera to other human coronaviruses (CoVs). The developed SARS-CoV-2 S1 subunit of the spike glycoprotein and nucleocapsid (N)-based ELISAs not only showed high specificity and sensitivity but also did not show any cross-reactivity with other CoVs. We also show that all RT-PCR confirmed COVID-19 patients tested in our study developed both virus specific IgM and IgG antibodies as early as week one after disease onset. Our data also suggest that the inclusion of both S1 and N in serological testing would capture as many potential SARS-CoV-2 positive cases as possible than using any of them alone. This is specifically important for tracing contacts and cases and conducting large-scale epidemiological studies to understand the true extent of virus spread in populations.

Generation of MERS-CoV Pseudotyped Viral Particles for the Evaluation of Neutralizing Antibodies in Mammalian Sera

Pseudotyped viral particle production has been used extensively and broadly for many viruses to evaluate levels of neutralizing antibodies, viral entry inhibitors and vaccine immunogenicity. This assay is extremely safe and useful alternative to live virus-based assay without the need for high containment facilities. In this chapter, we describe the generation of MERS-CoV pseudotyped viral particles (MERSpp) expressing full-length spike protein using second-generation lentiviral packaging system. This platform is optimized to generate high titer of MERSpp and to test sera from different mammalian species.

Evaluation of Neutralizing Antibodies Against Highly Pathogenic Coronaviruses: A Detailed Protocol for a Rapid Evaluation of Neutralizing Antibodies Using Vesicular Stomatitis Virus Pseudovirus-Based Assay

Emerging highly pathogenic human coronaviruses (CoVs) represent a serious ongoing threat to the public health worldwide. The spike (S) proteins of CoVs are surface glycoproteins that facilitate viral entry into host cells via attachment to their respective cellular receptors. The S protein is believed to be a major immunogenic component of CoVs and a target for neutralizing antibodies (nAbs) and most candidate vaccines. Development of a safe and convenient assay is thus urgently needed to determine the prevalence of CoVs nAbs in the population, to study immune response in infected individuals, and to aid in vaccines and viral entry inhibitor evaluation. While live virus-based neutralization assays are used as gold standard serological methods to detect and measure nAbs, handling of highly pathogenic live CoVs requires strict bio-containment conditions in biosafety level-3 (BSL-3) laboratories. On the other hand, use of replication-incompetent pseudoviruses bearing CoVs S proteins could represent a safe and useful method to detect nAbs in serum samples under biosafety level-2 (BSL-2) conditions. Here, we describe a detailed protocol of a safe and convenient assay to generate vesicular stomatitis virus (VSV)-based pseudoviruses to evaluate and measure nAbs against highly pathogenic CoVs. The protocol covers methods to produce VSV pseudovirus bearing the S protein of the Middle East respiratory syndrome-CoV (MERS-CoV) and the severe acute respiratory syndrome-CoV-2 (SARS-CoV-2), pseudovirus titration, and pseudovirus neutralization assay. Such assay could be adapted by different laboratories and researchers working on highly pathogenic CoVs without the need to handle live viruses in the BSL-3 environment.

Phage Display Derived Monoclonal Antibodies: From Bench to Bedside

Monoclonal antibodies (mAbs) have become one of the most important classes of biopharmaceutical products, and they continue to dominate the universe of biopharmaceutical markets in terms of approval and sales. They are the most profitable single product class, where they represent six of the top ten selling drugs. At the beginning of the 1990s, an in vitro antibody selection technology known as antibody phage display was developed by John McCafferty and Sir. Gregory Winter that enabled the discovery of human antibodies for diverse applications, particularly antibody-based drugs. They created combinatorial antibody libraries on filamentous phage to be utilized for generating antigen specific antibodies in a matter of weeks. Since then, more than 70 phage–derived antibodies entered clinical studies and 14 of them have been approved. These antibodies are indicated for cancer, and non-cancer medical conditions, such as inflammatory, optical, infectious, or immunological diseases. This review will illustrate the utility of phage display as a powerful platform for therapeutic antibodies discovery and describe in detail all the approved mAbs derived from phage display.