POSSIBLE ROLE OF PEPTIDE EPITOPES OF COVID-19 BNT-162B2 MRNA VACCINE IN FOMENTING AUTOIMMUNITY: AN IN SILICO ANALYSIS

BackgroundFollowing the launch of the global COVID-19 vaccination campaign, there have been increased reports of autoimmune diseases developing de novo following vaccination. These cases include rheumatoid arthritis, autoimmune hepatitis, immune thrombotic thrombocytopenia, and connective tissue diseases. Nevertheless, COVID-19 vaccines are considered safe for patients with autoimmune diseases and are strongly recommended.ObjectivesThe aim of this in silico analysis is to investigate the presence of protein epitopes encoded by the BNT-162b2 mRNA vaccine, one of the most commonly administered COVID-19 vaccines, that could elicit an aberrant adaptive immune response in predisposed individuals.MethodsThe FASTA sequence of the protein encoded by the BNT-162b2 vaccine was retrieved from http://genome.ucsc.edu and used as a key input to the Immune Epitope Database and Analysis Resource (www.iedb.org). Linear peptides with 90% BLAST homology were selected, and T-cell, B-cell, and MHC ligand assays without MHC restriction were searched and evaluated. HLA-disease associations were screened on the HLA-SPREAD platform (https://hla-spread.igib.res.in) by selecting only positive markers.ResultsA total of 183 epitopes were found, corresponding to 178 SARS-CoV-2 and 5 SARS-CoV spike epitopes, respectively. Results were obtained from 22 T-cell assays, 398 B-cell assays, and 2 MHC ligand assays. Complementary receptors included 1080 T-cell receptors and 0 B-cell receptors.Specifically, the IEDB_epitope:1329790 (NATNVVIKVCEFQFCNDPFLGVYY) was shown to bind to HLA-DRB1*15:02 and HLA-DRB1*15:03 alleles, whereas the IEDB_epitope:1392457 (TKCTLKSFTVEKGIYQTSNFRVQPT) was reported to bind to HLA-DRB1*07:01, HLA-DRB1*03:01, HLA-DRB3*01:01, and HLA-DRB4*01:01 alleles. The HLA alleles detected were found to be positively associated with various immunological disorders (Table 1).Table 1.MHC-restricted epitopes of the BNT-162b2 vaccine and potentially associated immunological conditionsEpitopeAssayMHC moleculeAssociated disease (population)NATNVVIKVCEFQFCNDPFLGVYY + OX(C10)cellular MHC/mass spectrometry ligand presentationHLA-DRB1*15:02Takayasu arteritis (Japanese) Arthritis (Taiwanese) Scleroderma (Japanese) Colitis (Japanese)HLA-DRB1*15:03Systemic lupus erythematosus (Mexican American)TKCTLKSFTVEKGIYQTSNFRVQPT + SCM(K2)as aboveHLA-DRB1*07:01Allergy, hypersensitivity (Caucasian)HLA-DRB1*03:01Type 1 diabetes (African) Sarcoidosis, good prognosis (Finnish)HLA-DRB3*01:01Graves' disease (Caucasian) Thymoma (Caucasian) Sarcoidosis (Scandinavian) Autoimmune hepatitis (Caucasian)HLA-DRB4*01:01Vitiligo (Saudi Arabian)ConclusionSimilar to the SARS-CoV-2 spike protein, the protein product of the BNT-162b2 mRNA vaccine contains immunogenic epitopes that may trigger autoimmune phenomena in predisposed individuals. Genotyping for HLA alleles may help identify at-risk individuals. However, further research is needed to elucidate the underlying mechanisms and potential clinical implications.References[1]Vita R, Mahajan S, Overton JA et al. The Immune Epitope Database (IEDB): 2018 update. Nucleic Acids Res. 2019 Jan 8;47(D1):D339-D343. doi: 10.1093/nar/gky1006.[2]Dholakia D, Kalra A, Misir BR et al. HLA-SPREAD: a natural language processing based resource for curating HLA association from PubMed s. BMC Genomics 23, 10 (2022). https://doi.org/10.1186/s12864-021-08239-0[3]Parker R, Partridge T, Wormald C et al. Mapping the SARS-CoV-2 spike glycoprotein-derived peptidome presented by HLA class II on dendritic cells. Cell Rep. 2021 May 25;35(8):109179. doi: 10.1016/j.celrep.2021.109179.[4]Knierman MD, Lannan MB, Spindler LJ et al. The Human Leukocyte Antigen Class II Immunopeptidome of the SARS-CoV-2 Spike Glycoprotein. Cell Rep. 2020 Dec 1;33(9):108454. doi: 10.1016/j.celrep.2020.108454.Acknowledgements:NIL.Disclosure of InterestsNone Declared.

Examining the associations between COVID-19 infection and pediatric type 1 diabetes.

INTRODUCTION: The COVID-19 pandemic represents an unprecedented challenge for public health worldwide, not only for the very high number of cases and deaths but also due to a wide variety of indirect consequences. Among these, the possible relationship between SARS-CoV-2 infection and type 1 diabetes (T1D) in pediatric age has aroused notable interest in the scientific community. AREAS COVERED: This perspective article aims to focus on the epidemiological trend of T1D during the pandemic, the diabetogenic role of SARS-CoV-2, and the influence of preexisting T1D on COVID-19 outcomes. EXPERT OPINION: The incidence of T1D has considerably changed during the COVID-19 pandemic, but any direct role of SARS-CoV-2 is uncertain. It is more likely that SARS-CoV-2 infection acts as an accelerator of pancreatic ß-cell immunological destruction, which is activated by known viral triggers whose spread has been abnormal during these pandemic years. Another interesting aspect to consider is the role of immunization as a potential protective factor both for T1D development and the risk of severe outcomes in already diagnosed patients. Future studies are still required to address unmet needs, including the early use of antiviral drugs to reduce the risk of metabolic decompensation in children with T1D.

COVID-19 induced Diabetes: A novel presentation.

INTRODUCTION: The COVID-19 pandemic disproportionately affected patients who had comorbid diabetes mellitus. COVID-19 patients with diabetes experience significantly higher rates of complications and mortality. COVID-induced diabetes is a novel phenomenon observed in critically ill patients. The aims of this review were to explore the literature about COVID-induced diabetes and the pathophysiological mechanisms that could lead to this novel presentation. METHODS: A literature search was performed using PUBMED, Google Scholar, MEDLINE and Embase for original studies (meta-analyses, cross-sectional studies, case series, case reports) about new-onset diabetes following COVID infection, and the proposed biochemical pathways behind this presentation. It was assumed that the authors of the studies used the current diagnostic criteria for diagnosis of type 1 and type 2 diabetes. RESULTS: COVID-19 causes dysregulation of glucose homeostasis leading to new-onset diabetes and hyperglycaemia. This is also seen in patients with no previous risk factors for diabetes mellitus. The atypical glycaemic parameters and increased rates of DKA suggest that COVID-induced diabetes is a novel form of diabetes. A spectrum of COVID-induced diabetes has also been noted. COVID-induced diabetes is associated with remarkably higher mortality rates and worse outcomes compared to COVID-19 patients with pre-existing diabetes. The novel presentation of COVID-induced diabetes could be due to beta cell damage and insulin resistance caused by SARS-CoV-2. CONCLUSION: COVID-induced diabetes is essential to detect early, owing to its implications on prognosis. Further studies must include follow-up of these patients to better understand the trajectory of COVID-induced diabetes and the best management plan. It is also important to assess the beta cell function and insulin resistance of COVID-induced diabetes patients over time to better understand the underlying biochemical mechanisms.

Diabetes and SARS-CoV-2-Is There a Mutual Connection?

SARS-CoV-2, a newly emerged virus described for the first time in late 2019, affects multiple organs in humans, including the pancreas. Here, we present the bilateral link between the pathophysiology of diabetes and COVID-19, with diabetes being COVID-19 comorbidity, and a complication of SARS-CoV-2 infection. Analysis of clinical data indicates that patients with chronic conditions like diabetes are at increased risk of severe COVID-19, hospitalization, ICU admission, and death compared to the healthy subjects. Further, we show that SARS-CoV-2 infection might be also associated with the development of new-onset diabetes and diabetic ketoacidosis. We then discuss the options for studying SARS-CoV-2 infection in pancreatic settings, including the use of human pluripotent stem cell-derived pancreatic organoids. Further, we review the presence of SARS-CoV-2 receptors in different pancreatic cell types and the infection efficiency based on pancreatic sections from COVID-19 patients and primary human islet in vitro studies. Finally, we discuss the impact of SARS-CoV-2 infection on human pancreatic cell homeostasis, focusing on ß-cells.

Exercise as a non-pharmacological intervention to protect pancreatic beta cells in individuals with type 1 and type 2 diabetes.

AIMS/HYPOTHESIS: Diabetes is characterised by progressive loss of functional pancreatic beta cells. None of the therapeutic agents used to treat diabetes arrest this process; preventing beta cell loss remains a major unmet need. We have previously shown that serum from eight young healthy male participants who exercised for 8 weeks protected human islets and insulin-producing EndoC-ßH1 cells from apoptosis induced by proinflammatory cytokines or the endoplasmic reticulum (ER) stressor thapsigargin. Whether this protective effect is influenced by sex, age, training modality, ancestry or diabetes is unknown. METHODS: We enrolled 82 individuals, male or female, non-diabetic or diabetic, from different origins, in different supervised training protocols for 8-12 weeks (including training at home during the COVID-19 pandemic). EndoC-ßH1 cells were treated with 'exercised' serum or with the exerkine clusterin to ascertain cytoprotection from ER stress. RESULTS: The exercise interventions were effective and improved [Formula: see text] values in both younger and older, non-obese and obese, non-diabetic and diabetic participants. Serum obtained after training conferred significant beta cell protection (28% to 35% protection after 4 and 8 weeks of training, respectively) from severe ER stress-induced apoptosis. Cytoprotection was not affected by the type of exercise training or participant age, sex, BMI or ancestry, and persisted for up to 2 months after the end of the training programme. Serum from exercised participants with type 1 or type 2 diabetes was similarly protective. Clusterin reproduced the beneficial effects of exercised sera. CONCLUSIONS/INTERPRETATION: These data uncover the unexpected potential to preserve beta cell health by exercise training, opening a new avenue to prevent or slow diabetes progression through humoral muscle-beta cell crosstalk.

COVID Associated Insulitis in Type 1 Diabetes

Recent reports suggest a potential relationship between COVID-and onset of diabetes (DM) . We present the case of a 35 yr old female with type 1 DM (T1DM) who following COVID-pneumonia (COVP) developed worsening insulitis suggesting a potential direct effect of COVID-on beta cell function. The patient is a 35 yr old Caucasian female with T1DM first diagnosed 5 yrs ago. She had some residual beta cell secretory function with fasting C-peptide;0.51 (0-8-3.85ng/ml) . She also has hemochromatosis, thyroiditis with thyroid nodular disease and +ve history of T1DM in her older brother and maternal cousin. Since diagnosis she has been on insulin pump therapy and a CGMS device with excellent glycemic control and HBA1c of 6.7-7.1. She had not received the COVID-vaccine and had COVP in July 2021 requiring inpatient care but not intubation. She received oral steroids and Remdesivir with salutary response. She has not had post-acute sequelae of SARS-CoV (PASC) but ˜ 2 months post discharge had acute thyroiditis with no thyroid abscess, elevated sed rate, leucocytosis and peak thyroglobulin;158 (3-40ng/ml) . Since discharge she noted persistent global hyperglycemia requiring increased basal and bolus insulin therapy with peak HBA1c of 8.3. Further evaluation showed active insulitis with reduced C-peptide 0.and increase in islet related antibodies compared to titers obtained at the time of initial diagnosis 5 yrs prior. The clinical presentation of our patient suggests a potential role of COVID-in inducing insulitis with significant implications for at risk patients including T1DM patients with preserved islet function but also type 2 DM and LADA patients. This case provides another compelling reason for advocating COVID-vaccination in at risk patients. The duration of this effect on islet function and whether beta cell functional recovery is possible over time remains to be seen. The insulitis manifests with worsening glycemic profiles as well as possibly impacting islet mediated counterregulatory glycemic responses.

Gene Networks of Hyperglycemia, Diabetic Complications, and Human Proteins Targeted by SARS-CoV-2: What Is the Molecular Basis for Comorbidity?

People with diabetes are more likely to have severe COVID-19 compared to the general population. Moreover, diabetes and COVID-19 demonstrate a certain parallelism in the mechanisms and organ damage. In this work, we applied bioinformatics analysis of associative molecular networks to identify key molecules and pathophysiological processes that determine SARS-CoV-2-induced disorders in patients with diabetes. Using text-mining-based approaches and ANDSystem as a bioinformatics tool, we reconstructed and matched networks related to hyperglycemia, diabetic complications, insulin resistance, and beta cell dysfunction with networks of SARS-CoV-2-targeted proteins. The latter included SARS-CoV-2 entry receptors (ACE2 and DPP4), SARS-CoV-2 entry associated proteases (TMPRSS2, CTSB, and CTSL), and 332 human intracellular proteins interacting with SARS-CoV-2. A number of genes/proteins targeted by SARS-CoV-2 (ACE2, BRD2, COMT, CTSB, CTSL, DNMT1, DPP4, ERP44, F2RL1, GDF15, GPX1, HDAC2, HMOX1, HYOU1, IDE, LOX, NUTF2, PCNT, PLAT, RAB10, RHOA, SCARB1, and SELENOS) were found in the networks of vascular diabetic complications and insulin resistance. According to the Gene Ontology enrichment analysis, the defined molecules are involved in the response to hypoxia, reactive oxygen species metabolism, immune and inflammatory response, regulation of angiogenesis, platelet degranulation, and other processes. The results expand the understanding of the molecular basis of diabetes and COVID-19 comorbidity.

Mechanism of physical activity in the prevention and management of type 2 diabetes mellitus: A short review

Background: Pre-diabetes (PDM) is a state with impaired glucose tolerance and/or impaired fasting glucose where people are at risk for diabetes. In less than 3 years, PDM gets converted to diabetes. Physical activity (PA) is a boon to PDM and diabetes to gain control over the glycemic variability and insulin secretion, reduction in cardiometabolic risk, and improvement in overall health. Increasing PA helps delay or prevent the conversion of PDM to diabetes mellitus (DM), as well as helps prevent complications of diabetes effectively. Materials and Methods: The aim of the review was to understand the mechanism by which PA can help to prevent and manage DM. Research papers, manuscripts, and review papers on PA and its mechanism of action on prevention and management of diabetes were searched and relevant contents were studied. One hundred and twelve papers were chosen from online sources like Google Scholar, Scopus, PubMed, Sci-Hub, and Library Genesis. Fifty-seven articles were shortlisted and out of them 54 included in this mini-review comprising of meta-analysis, systematic review, and randomized control trials. Fifty-seven articles were excluded due to irrelevant content in the contexts of diabetes and its mechanism. Result: The review resulted in getting a better understanding of the possible mechanisms by which PA works in prevention and management of DM and delaying the onset of diabetes in PDM. In addition to that, the highest known risk factors for diabetes in this current scenario are understood as physical inactivity among youngsters, along with low nutrition high-quality diet, stress, low-quality sleep, and associated fat and glucose metabolism. Conclusion: During pandemics like coronavirus disease 2019 (COVID-19), physically being active also has its role in reducing resistance power and metabolism of fat and glucose, thereby increasing the risk for diabetes. It is always better to keep oneself with some exercise daily to maintain surface immunity high and strong to avoid diseases. This is possible by modification of lifestyle with yoga, exercises, and proper diet. Periodic incorporation of indoor-outdoor activities aiming at cutting short period of inactivity will help prevent and manage diabetes and other metabolic endocrine disorders to a large extent.

ACE2 function in the pancreatic islet: Implications for relationship between SARS-CoV-2 and diabetes.

The molecular link between SARS-CoV-2 infection and susceptibility is not well understood. Nonetheless, a bi-directional relationship between SARS-CoV-2 and diabetes has been proposed. The angiotensin-converting enzyme 2 (ACE2) is considered as the primary protein facilitating SARS-CoV and SARS-CoV-2 attachment and entry into the host cells. Studies suggested that ACE2 is expressed in the endocrine cells of the pancreas including beta cells, in addition to the lungs and other organs; however, its expression in the islets, particularly beta cells, has been met with some contradiction. Importantly, ACE2 plays a crucial role in glucose homoeostasis and insulin secretion by regulating beta cell physiology. Given the ability of SARS-CoV-2 to infect human pluripotent stem cell-derived pancreatic cells in vitro and the presence of SARS-CoV-2 in pancreatic samples from COVID-19 patients strongly hints that SARS-CoV-2 can invade the pancreas and directly cause pancreatic injury and diabetes. However, more studies are required to dissect the underpinning molecular mechanisms triggered in SARS-CoV-2-infected islets that lead to aggravation of diabetes. Regardless, it is important to understand the function of ACE2 in the pancreatic islets to design relevant therapeutic interventions in combatting the effects of SARS-CoV-2 on diabetes pathophysiology. Herein, we detail the function of ACE2 in pancreatic beta cells crucial for regulating insulin sensitivity, secretion, and glucose metabolism. Also, we discuss the potential role played by ACE2 in aiding SARS-COV-2 entry into the pancreas and the possibility of ACE2 cooperation with alternative entry factors as well as how that may be linked to diabetes pathogenesis.

Early-Onset Type 2 Diabetes Mellitus.

Globally, the prevalence of chronic, non-communicable diseases is increasing at an alarming rate. Amongst it, Type 2 diabetes mellitus (DM) is becoming more prevalent among young individuals due to obesity and sedentary habits. With the advent of COVID-19, there has been an increasing trend for diabetes and its complications. Here we describe a 13-year-old female girl with polyuria, polydipsia for two months with further assessment leading to a diagnosis of Type 2 DM who is now closely monitored by a pediatric endocrinologist. She remains euglycemic with insulin and lifestyle changes. Early-onset DM is complex and requires multidisciplinary care for preventing complications and comorbidities. Hence, early recognition and management are crucial.

Visceral Adipose Tissue: A New Target Organ in Virus-Induced Type 1 Diabetes.

Type 1 diabetes (T1D) is a proinflammatory pathology that leads to the specific destruction of insulin producing ß-cells and hyperglycaemia. Much of the knowledge about type 1 diabetes (T1D) has focused on mechanisms of disease progression such as adaptive immune cells and the cytokines that control their function, whereas mechanisms linked with the initiation of the disease remain unknown. It has been hypothesized that in addition to genetics, environmental factors play a pivotal role in triggering ß-cell autoimmunity. The BioBreeding Diabetes Resistant (BBDR) and LEW1.WR1 rats have been used to decipher the mechanisms that lead to virus-induced T1D. Both animals develop ß-cell inflammation and hyperglycemia upon infection with the parvovirus Kilham Rat Virus (KRV). Our earlier in vitro and in vivo studies indicated that KRV-induced innate immune upregulation early in the disease course plays a causal role in triggering ß-cell inflammation and destruction. Furthermore, we recently found for the first time that infection with KRV induces inflammation in visceral adipose tissue (VAT) detectable as early as day 1 post-infection prior to insulitis and hyperglycemia. The proinflammatory response in VAT is associated with macrophage recruitment, proinflammatory cytokine and chemokine upregulation, endoplasmic reticulum (ER) and oxidative stress responses, apoptosis, and downregulation of adipokines and molecules that mediate insulin signaling. Downregulation of inflammation suppresses VAT inflammation and T1D development. These observations are strikingly reminiscent of data from obesity and type 2 diabetes (T2D) in which VAT inflammation is believed to play a causal role in disease mechanisms. We propose that VAT inflammation and dysfunction may be linked with the mechanism of T1D progression.

Durable SARS-CoV-2 B cell immunity after mild or severe disease.

Multiple studies have shown loss of severe acute respiratory syndrome coronavirus 2-specific (SARS-CoV-2-specific) antibodies over time after infection, raising concern that humoral immunity against the virus is not durable. If immunity wanes quickly, millions of people may be at risk for reinfection after recovery from coronavirus disease 2019 (COVID-19). However, memory B cells (MBCs) could provide durable humoral immunity even if serum neutralizing antibody titers decline. We performed multidimensional flow cytometric analysis of S protein receptor binding domain-specific (S-RBD-specific) MBCs in cohorts of ambulatory patients with COVID-19 with mild disease (n = 7), and hospitalized patients with moderate to severe disease (n = 7), at a median of 54 days (range, 39-104 days) after symptom onset. We detected S-RBD-specific class-switched MBCs in 13 of 14 participants, failing only in the individual with the lowest plasma levels of anti-S-RBD IgG and neutralizing antibodies. Resting MBCs (rMBCs) made up the largest proportion of S-RBD-specific MBCs in both cohorts. FCRL5, a marker of functional memory on rMBCs, was more dramatically upregulated on S-RBD-specific rMBCs after mild infection than after severe infection. These data indicate that most SARS-CoV-2-infected individuals develop S-RBD-specific, class-switched rMBCs that resemble germinal center-derived B cells induced by effective vaccination against other pathogens, providing evidence for durable B cell-mediated immunity against SARS-CoV-2 after mild or severe disease.

Comorbid illnesses are associated with altered adaptive immune responses to SARS-CoV-2.

Comorbid medical illnesses, such as obesity and diabetes, are associated with more severe COVID-19, hospitalization, and death. However, the role of the immune system in mediating these clinical outcomes has not been determined. We used multiparameter flow cytometry and systems serology to comprehensively profile the functions of T cells and antibodies targeting spike, nucleocapsid, and envelope proteins in a convalescent cohort of COVID-19 subjects who were either hospitalized (n = 20) or not hospitalized (n = 40). To avoid confounding, subjects were matched by age, sex, ethnicity, and date of symptom onset. Surprisingly, we found that the magnitude and functional breadth of virus-specific CD4+ T cell and antibody responses were consistently higher among hospitalized subjects, particularly those with medical comorbidities. However, an integrated analysis identified more coordination between polyfunctional CD4+ T cells and antibodies targeting the S1 domain of spike among subjects who were not hospitalized. These data reveal a functionally diverse and coordinated response between T cells and antibodies targeting SARS-CoV-2, which is reduced in the presence of comorbid illnesses that are known risk factors for severe COVID-19.

A Human Pluripotent Stem Cell-based Platform to Study SARS-CoV-2 Tropism and Model Virus Infection in Human Cells and Organoids.

SARS-CoV-2 has caused the COVID-19 pandemic. There is an urgent need for physiological models to study SARS-CoV-2 infection using human disease-relevant cells. COVID-19 pathophysiology includes respiratory failure but involves other organ systems including gut, liver, heart, and pancreas. We present an experimental platform comprised of cell and organoid derivatives from human pluripotent stem cells (hPSCs). A Spike-enabled pseudo-entry virus infects pancreatic endocrine cells, liver organoids, cardiomyocytes, and dopaminergic neurons. Recent clinical studies show a strong association with COVID-19 and diabetes. We find that human pancreatic beta cells and liver organoids are highly permissive to SARS-CoV-2 infection, further validated using adult primary human islets and adult hepatocyte and cholangiocyte organoids. SARS-CoV-2 infection caused striking expression of chemokines, as also seen in primary human COVID-19 pulmonary autopsy samples. hPSC-derived cells/organoids provide valuable models for understanding the cellular responses of human tissues to SARS-CoV-2 infection and for disease modeling of COVID-19.