Characterization of Adaptive Immune Responses to SARS-CoV-2 Updated Bivalent Booster

Bivalent COVID-19 vaccines that contain two mRNAs encoding Wuhan-1 and Omicron BA.4/5 spike proteins are successful in preventing infection from the original strain and Omicron variants, but the quality of adaptive immune responses is still not well documented. This study aims at characterizing adaptive immune responses to the bivalent booster vaccination in 46 healthy participants. Plasma and PBMC were collected prior and three weeks after bivalent booster. We measured anti-N, anti-S, and RBD IgM, IgA, IgG plasma titers against original, Omicron BA.1, and BA.5 variants (pending) as well as total anti-S IgG titers and surrogate Virus Neutralization capacity against the Alpha, Delta, and BA.1 variant. With spectral flow-cytometry we identified peripheral blood B-cells specific for the RBD of the S-protein of the original and BA.1 variants. T-cell-specific responses were assessed by cytokine release assay after stimulation with SARS-CoV-2 peptides from the original, BA.1, BA.4, and BA.5 variants (pending). Finally, we performed TRB and IGH repertoire studies on sorted CD4+, CD8+, CD19+ lymphocytes, to study breadth of SARS-CoV-2 specific clonotypes (pending). 27/46 participants were analyzed;9 had SARS-CoV-2 infection (COVID+), while 18 are infection naive (COVID-). In both groups, median time since last dose of SARS-CoV-2 vaccine (3rd or 4th) was 11 months. All subjects were positive for anti-S IgG prior to bivalent booster. The COVID + group displayed anti-S IgG pre-booster levels and neutralization against BA.1 higher than the COVID- group. Significant increase post-boost of total anti-S IgG and BA.1 neutralizing activity was detected in the COVID- but not in the COVID+ group;however, no difference in neutralization activity post-boost was detected between the two groups. Furthermore, the COVIDgroup showed significant increase in the frequency of CD19+ and CD27+ switched memory B-cells specific for BA.1 RBD in post-boost compared to pre-boost samples. However, post-boost frequencies of the same B-cells were higher in the COVID+ compared to the COVID- group. These preliminary findings confirm that among individual immunized with the original COVID-19 mRNAvaccine, prior COVID infection provides increased protection against SARS-CoV-2 variants. They also demonstrate that booster immunization with the bivalent vaccine induces robust adaptive immune responses against Omicron variant.[Formula presented][Formula presented]Copyright © 2023 Elsevier Inc.

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.

Boosting the Immune System with Vitamin D: Special Focus on Prevention of COVID-19 and Complications

In addition to the classical functions of the musculoskeletal system and calcium homeostasis, the function of vitamin D as an immune modulator is well established. The vitamin D receptors and enzymes that metabolize vitamin D are ubiquitously expressed in most cells in the body, including T and B lymphocytes, antigen-presenting cells, monocytes, macrophages and natural killer cells that trigger immune and antimicrobial responses. Many in vitro and in vivo studies revealed that vitamin D promotes tolerogenic immunological action and immune modulation. Vitamin D adequacy positively influences the expression and release of antimicrobial peptides, such as cathelicidin, defensin, and anti-inflammatory cytokines, and reduces the expression of proinflammatory cytokines. Evidence suggestss that vitamin D's protective immunogenic actions reduce the risk, complications, and death from COVID-19. On the contrary, vitamin D deficiency worsened the clinical outcomes of viral respiratory diseases and the COVID-19-related cytokine storm, acute respiratory distress syndrome, and death. The study revealed the need for more preclinical studies and focused on well-designed clinical trials with adequate sizes to understand the role of vitamin D on the pathophysiology of immune disorders and mechanisms of subduing microbial infections, including COVID-19.Copyright © 2023 Bentham Science Publishers.

Knowledge of African Traditional Medicine System: Immunomodulation

African traditional medicine is one of the oldest forms of health-care system in the continent that has continued to be relevant. It is usually holistic, treating mind and body, and includes aromatherapy, bone setting, circumcision, herbs, homeopathy massaging, spiritual therapies, maternity care, psychiatric care, music therapy, and many more. It is a very old and culturally informed method of health management that humans have used against diseases that have threatened existence. More than 60,000 of the world's higher plant species can be found in sub-Saharan Africa and the Indian Ocean Islands. These are about one-fourth of the global total and less than the 8% of the medicinal plants sold internationally from Africa. This scarcity could be due to lack of data on the traditional uses of many African plants as the knowledge is transferred orally by storytellers and traditional healers though in recent times, there are some information in print. Immunomodulation is seen as an essential feature of immunotherapy whereby immune responses are provoked, heightened, decreased, or avoided. Immune responses have been observed to be either cellular co-receptor expression, class switching, cytokine secretion, histamine release, immunoglobulin secretion, lymphocyte expression, or phagocytosis. Immune system dysfunction is responsible for various diseases like allergies, asthmas, arthritis, cancers, and infectious diseases. So modulation of immune responses is required in controlling diseases. This is requisite nowadays because of the upsurge of infectious diseases like superbugs caused by Multi-Resistant Staphylococcus aureus (MRSA) and the coronavirus (COVID-19) plus other emerging diseases. The historical view of African Traditional Medicine (ATMs) will be discussed from the point of view of specific plants used for immunomodulation in the ATMs and their efficacies following the trend of use and development of herbal medicines from crude formulations to refined dosage forms and procedures over time. Most of the ATMs are prepared as tonics and bitters to heighten and keep up immune defenses. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.

Should Young Covid-19 Patients be Suplemented with Vitamin D?

It is well known that vitamin D's general immunomodulatory actions are helpful in viral infections and that a shortage is linked to a more serious prognosis for Covid-19. In this sistematic review, we examined the existing literature on evidence as to whether there is also link between vitamin D range levels in pediatric population and the outcome of the Covid-19 infection. We looked for studies that measured vitamin D blood concentrations and examined the effects of vitamin D supplementation in young infected patients. Vitamin D may decrease the risk of respiratory infections in a number of ways through its interactions with numerous cells, including by decreasing viral survival and replication, reducing the cytokine storm, raising angiotensin-converting enzyme 2 concentrations (ACE2) while not damaging the endothelial integrity. The incidence or severity of Covid-19 is linked with blood 25-hydroxyvitamin D concentrations, according to many observational studies. However experimental verification is still needed. Given their safety and broad therapeutic window, vitamin D supplements seem to be an effective way for individuals and doctors to prevent or treat Covid-19. Nonetheless, the outcomes of significant vitamin D randomized controlled trials are further needed.Copyright © 2022 Maria Nicolae et al., published by Sciendo.

Altered immune response to vaccination in patients with plasma cell premalignancy

Introduction Patients with hematological malignancies, including multiple myeloma (MM), experience suboptimal responses to SARS-CoV-2 vaccination. Monoclonal Gammopathy of Undetermined Significance (MGUS) and Smoldering Multiple Myeloma (SMM) are precursors to MM and exhibit altered immune cell composition and function. The SARS-CoV-2 pandemic and the subsequent population-wide vaccination represent an opportunity to study the real-life immune response to a common antigen. Here, we present updated results from the IMPACT study, a study we launched in November 2020 to characterize the effect of plasma cell premalignancy on response to SARS-CoV2 vaccination (vx). Methods We performed: (i) ELISA for SARS-CoV-2-specific antibodies on 1,887 peripheral blood (PB) samples (237 healthy donors (HD), and 550 MGUS, 947 SMM, and 153 MM patients) drawn preand post-vx;(ii) single-cell RNA, T cell receptor (TCR), and B cell receptor (BCR) sequencing (10x Genomics) on 224 PB samples (26 HD, and 20 MGUS, 48 SMM, and 24 MM patients) drawn preand post-vx;(iii) plasma cytokine profiling (Olink) on 106 PB samples (32 HD, and 38 MGUS and 36 SMM patients) drawn pre- and post-vx;and (iv) bulk TCR sequencing (Adaptive Biotechnologies) on 8 PB samples from 4 patients (2 MGUS, 2 SMM) drawn pre- and post-vx. Results Patients with MGUS and SMM achieved comparable antibody titers to HD two months post-vx. However, patient titers waned significantly faster, and 4 months post-vx we observed significantly lower titers in both MGUS (Wilcoxon rank-sum, p=0.030) and SMM (p=0.010). These results indicate impaired humoral immune response in patients with MGUS and SMM.At baseline, the TCR repertoire was significantly less diverse in patients with SMM compared to HD (Wilcoxon rank-sum, p=0.039), while no significant difference was observed in the BCR repertoire (p=0.095). Interestingly, a significant increase in TCR repertoire diversity was observed post-vx in patients with SMM (paired t-test, p=0.014), indicating rare T cell clone recruitment in response to vaccination. In both HD and patients, recruited clones showed upregulation of genes associated with CD4+ naive and memory T cells, suggesting preservation of the T cell response in SMM, which was confirmed by bulk TCR-sequencing in 4 patients.Lastly, by cytokine profiling, we observed a defect in IL-1beta and IL-18 induction post-vx in patients with SMM compared to HD (Wilcoxon rank-sum, p=0.047 and p=0.015, respectively), two key monocyte-derived mediators of acute inflammation, suggesting an altered innate immune response as well. Conclusion Taken together, our findings highlight that despite the absence of clinical manifestations, plasma cell premalignancy is associated with defects in both innate and adaptive immune responses. Therefore, patients with plasma cell premalignancy may require adjusted vaccination strategies for optimal immunization.

Scientific rationale of Indian AYUSH Ministry advisory for COVID-19 prevention, prophylaxis, and immunomodulation

The current outbreak of COVID-19 is caused by the SARS-CoV-2 virus that has affected > 210 countries. Various steps are taken by different countries to tackle the current war-like health situation. In India, the Ministry of AYUSH released a self-care advisory for immunomodulation measures during the COVID-19 and this review article discusses the detailed scientific rationale associated with this advisory. Authors have spotted and presented in-depth insight of advisory in terms of immunomodulatory, antiviral, antibacterial, co-morbidity associated actions, and their probable mechanism of action. Immunomodulatory actions of advised herbs with no significant adverse drug reaction/toxicity strongly support the extension of advisory for COVID-19 prevention, prophylaxis, mitigations, and rehabilitation capacities. This advisory also emphasized Dhyana (meditation) and Yogasanas as a holistic approach in enhancing immunity, mental health, and quality of life. The present review may open-up new meadows for research and can provide better conceptual leads for future researches in immunomodulation, antiviral-development, psychoneuroimmunology, especially for COVID-19.Copyright © 2021, Institute of Korean Medicine, Kyung Hee University.

THE IMPACT OF IMMUNOMODULATING TREATMENT ON THE SEROLOGICAL IMMUNOGENICITY FOLLOWING THREE DOSES OF COVID-19 VACCINE AND PERSISTENCE OF IMMUNOGENICITY OF TWO VACCINE DOSES IN PATIENTS WITH INFLAMMATORY RHEUMATIC DISEASES - A SWEDISH STUDY (COVID19-REUMA)

BackgroundData on serological immunity after three doses and the long-term immunogenicity (persistence) of COVID-19 vaccine in patients with inflammatory rheumatic diseases (IRD) treated with different immunomodulating drugs are still limited.ObjectivesTo elucidate if 1) a third dose COVID-19 vaccine improves antibody responses, compared to two doses, in patients with IRD treated with biologic or targeted synthetic DMARD (b/tsDMARDs) treatment given as monotherapy or in combination with conventional synthetic DMARDs (csDMARDs) compared to controls, and 2) the persistence of antibody response after two doses of COVID-19 vaccine in IRD patients.MethodsAntibody levels to two antigens representing Spike full length protein and Spike S1 and a Nucleocapsid C-terminal fragment (used to confirm previous COVID-19 infection) were measured in serum samples collected 2-12 and 21-40 weeks after the second vaccine dose and 2-12 weeks after the third dose using a multiplex bead-based serology assay. A sufficient antibody response (seropositivity) was defined as having antibodies over the cut-off level for both spike antigens (1). WT (wild type) anti-Spike IgG and omicron BA.1 and BA.2 variants were measured. Patients with IRD receiving immunomodulating treatment, regularly followed at a rheumatology department and a group of controls were recruited from five Swedish region.ResultsIn total, 323 of 414 patients with IRD and 36 controls who received three vaccine doses participated in this part of the study. Following treatment groups were included: rituximab (n=118;68% female;mean age 67 years), abatacept (n=18;72% female;mean age 64 years), IL6r inhibitors (n=60;73% female;mean age 64 years), JAK-inhibitors (n=44;80% female, mean age 52 years), TNF-inhibitors (n=59;70% female;mean age 47 years;), IL12/23/17 inhibitors (n=24;46% female;mean age 54 years) and controls (n=36;75% female, mean age 51 years). b/ts DMARD treatment was given as monotherapy or in combination with csDMARD, methotrexate (MTX) being the most frequently used csDMARD (32.5%). Compared to results after two vaccine doses, proportion (%) of seropositivity after three vaccine doses increased significantly in groups rituximab +/- DMARD (p=0.003 and p=0.004, respectively), IL6r inhibitors +DMARD (p=0.02), and abatacept+DMARD (p=0.01). However, the proportion of seropositivity after three vaccine doses was still significantly lower in rituximab treated patients (52%) compared to other treatment groups or controls (p<0.001) (Figure 1A/B). Antibody response to WT, omicron sBA.1 and sBA.2 showed similar pattern with the lowest levels among patients treated with rituximab.When antibody response was compared between 2-12 weeks and 21-40 weeks after second dose, the proportion of seropositive rituximab treated patients decreased from 34.9 % to 32.6%. All patients with JAK inhibitors and with JAK-inhibitors and IL6r-inhibitors seropositive 21-40 weeks after the second vaccine dose. Patients treated with other bDMARDs were not included in this analysis due to limited number participants.ConclusionIn this Swedish study including IRD patients receiving different b/t DMARDs, a sufficient immunogenicity of the third dose of COVID-19 vaccine was observed in all treatments with exception for rituximab. However, the increased proportion of seropositivity after the third COVID-19 vaccine doses in rituximab and other patients with insufficient response to two doses including response to the omicron variants, supports the current recommendations on additional booster doses. The immunogenicity of two vaccine doses was preserved to 40 weeks in majority of patients treated with different immunomodulating treatment with exception for rituximab.Figure 1.AcknowledgementsThe study has been supported by the independent research grants from Roche.Disclosure of InterestsMartina Frodlund: None declared, Per Nived: None declared, Katerina Chatzidionysiou Consultant of: consultancy fees from Eli Lilly, AbbVie and Pfizer., Grant/research support from: Research grand from Galapagos, Anna ödergren: None declared, Eva Klingberg: None declared, Monika Hansson: None declared, Elisa Pin: None declared, Lars Klareskog: None declared, Meliha C Kapetanovic Grant/research support from: independent research grants från Pfizer and Roche.

Italian ancestral HLA haplotype predisposing to severe COVID-19 by low spike and high IFNalpha binding affinity

Background/Objectives: Validated association between COVID-19 and the most obvious candidate genes, e.g. HLA, is still missing. A weak association with class I HLA-C*04:01 was found for infection in Sardinians and for severity in another mixed population. Auto-antibodies to interferon type I have been implicated in the severity of COVID-19 in two studies. Method(s): The binding affinity between HLA molecules and SARS-CoV-2 spike protein and IFNalpha subunits was evaluated in silico. The presence of antibodies against one or more of the 12 IFNalpha subunits was evaluated in 160 hospitalized COVID-19 patients. The 10 most frequent haplotypes in the Italian population were tested in 1.997 SARS-CoV-2 infected patients (hospitalized versus not hospitalized). Result(s): The presence of auto-antibodies against at least one IFNalpha subunit was detected in 26% of patients. The haplotype A*24:02-B*35:02-C*04:01-DRB1*11:04-DQB1*03:01 was found to predispose to severity (p = 0.0018;p = 0.07 after Bonferroni correction) in patients <50 years. The haplotype includes alleles able to bind spike with low affinity (i.e. C*04:01 and DRB1*11:04) and IFNalpha with high affinity (i.e. DRB1*11:04). Conclusion(s): One of the 10 most frequent ancestral haplotype of the Italian population predisposes to severity likely reducing both innate immunity through IFNalpha auto-antibodies induction and adaptive immunity through weaker spike protein presentation.

CELLULAR AND HUMORAL IMMUNOGENICITY OF THE NEOANTIGEN S1 FROM SARS-COV-2 VACCINES IN PATIENTS WITH AUTOIMMUNE RHEUMATIC DISEASES

BackgroundData on cellular and humoral immunogenicity triggered by SARS-CoV-2 vaccines in patients with autoimmune rheumatic diseases (ARDs) are limited. While current vaccine efforts have focused on the induction of neutralizing antibodies against SARS-CoV-2, T-cell immunity may also provide protection against infection. Experimental data suggest that CD8+ T cell responses may have a protective role in the presence of decreasing or sub protective antibody titers [1].ObjectivesThe aim of this project is to describe the serological and T cell responses to the third dose of vaccine (either with BNT162b2 mRNA or ChAdOx1 nCoV-19 replication-deficient adenoviral vector vaccines) in a cohort of patients with ARDs (rheumatoid arthritis and spondyloarthropathies) treated with biologic therapies, to describe the impact of these treatments on vaccine response in this patient population. As a second objective, we will describe the characteristics of patients who did not present an adequate immunogenic response.MethodsCase-control study. We studied in 79 patients with ARDs and in 31 healthy controls, anti-SARS-CoV-2 specific interferon-gamma (IFN-γ) production measured by IGRA between 8-12 weeks after the third dose of anti-SARS-CoV-2 vaccine. In addition, humoral response was measured by anti-S1 IgG antibody production measured by chemiluminescent microparticle immunoassay. Statistical comparison between categorical variables was performed by Fisher's or χ2 test. For quantitative variables by Kruskal-Wallis test or Mann-Whitney test.Results79 patients with ARDs (48 women, 31 men;mean age 58±11.4) 43 (54%), with rheumatoid arthritis and 36 (45.6%) with spondyloarthropathies. 32 (49.5%) of them were on glucocorticoid treatment (mean dose 4.92 mg/day), 25 (31.6%) on methotrexate and 56 (70.9%) on anti-TNF. Post-vaccination results showed positive T-cell immune responses in 68 of 79 (86.1%) ARDs patients with mean IFN- γ anti-SARS-CoV-2 titers of 1,606.85 mUI/ml. 7 (8.9%) of ARDs patients showed negative IFN-γ SARS-CoV-2 levels, while 4 (5%) had borderline titers. 100% of patients with previous COVID 19 disease had positive cellular responses. Within the group of negative or borderline cellular responses, 7 of 10 were men (70%), with no significant differences in terms of diagnosis, comorbidities or immunosuppressive treatments used. In the control group, 100% presented positive cellular responses. Anti-Spike IgG antibodies were detectable in all patients with ARDs as in the control group.ConclusionOur preliminary data show that most patients with ARD were able to generate an adequate specific cellular response after vaccination against SARS-CoV-2, emphasizing the relevance of vaccination in this group. Specific antibody responses secondary to anti-SARS-CoV-2 vaccination were detected in all patients with ARD. Our data could support the relevance of these immune responses to personalize prevention, vaccination decision-making and treatment in this subgroup of patients.References[1]Sieiro Santos C, Calleja Antolin S, Moriano Morales C, Garcia Herrero J, Diez Alvarez E, Ramos Ortega F, et al. Immune responses to mRNA vaccines against SARS-CoV-2 in patients with immune-mediated inflammatory rheumatic diseases. RMD Open. 2022 Jan 5;8(1).Figure 1.Specific anti-SARS-CoV-2-IFN- γ responses measured by IGRA. Dotted lines represent positivity cut-off: ≥200mUI/ml. HC: Healthy controls. AIRDs: Autoimmune rheumatic diseases.[Figure omitted. See PDF]Acknowledgements:NIL.Disclosure of InterestsNone Declared.

Critical role of defensins in respiratory viral infection induced breast cancer progression

Respiratory viral infections (RVI) such as influenza and COVID19 impact the host systemic immune system along with causing deleterious chronic inflammatory responses and respiratory distress. While the role of chronic inflammation in cancer is well-established, the role of RVI on tumorigenesis is poorly defined. To study the role of RVI on breast cancer, we first infected murine respiratory epithelial cells (mRES) with murine sendai virus (mSV), an analog for human parainfluenza virus. These infected mRES were co-cultured with 4T1 murine breast cancer cells in 1:1 dilution on a single 2D plate and also in trans-well format. Both in co-culture and transwell culture we saw a 40- 80% (p<0.05) increased proliferation of breast cancer cells. Similarly, when 4T1 cells were treated with the supernatant collected from infected mRES cells in 1:5 dilution, also demonstrated a 2.3 fold increased breast cancer cell proliferation. The cytokine analysis from the supernatant collected from infected mRES cells demonstrated a 17-23 fold enhanced secretion of alpha/beta-defensins. Direct treatment of alpha-defensin (cyptidin-4, 10 pg/mL) and beta-defensin-3 (mBD3, 20 pg/mL) on 4T1 cells demonstrated enhanced expression of chemokine metastatic receptor, CXCR4 (4.3 fold), angiogenic factor, VEGF (12.8 fold) and cell division favoring factor, CDK2 (8.1 fold). Further, analysis of infected mRES cells demonstrated upregulation of toll-like receptor 2 (TLR2) and NODlike receptor protein 3 (NLRP3) expression. Interesting, co-cultured of infected mRES with syngeneic murine CD4 T cells induced exhaustion phenotype (PD1+ and CTLA4+ ) differentiation of CD4 T cells. Taken together, these data suggest that respiratory viral infections through induction of cancer cell proliferation and inhibiting anti-tumor adaptive immune responses promote breast cancer proliferation.

Hydroxytyrosol and Arginine as Antioxidant, Anti-Inflammatory and Immunostimulant Dietary Supplements for COVID-19 and Long COVID.

Phytochemicals from plant extracts are becoming increasingly popular in the world of food science and technology because they have positive effects on human health. In particular, several bioactive foods and dietary supplements are being investigated as potential treatments for chronic COVID. Hydroxytyrosol (HXT) is a natural antioxidant, found in olive oil, with antioxidant anti-inflammatory properties that has been consumed by humans for centuries without reported adverse effects. Its use was approved by the European Food Safety Authority as a protective agent for the cardiovascular system. Similarly, arginine is a natural amino acid with anti-inflammatory properties that can modulate the activity of immune cells, reducing the production of pro-inflammatory cytokines such as IL-6 and TNF-α. The properties of both substances may be particularly beneficial in the context of COVID-19 and long COVID, which are characterised by inflammation and oxidative stress. While l-arginine promotes the formation of •NO, HXT prevents oxidative stress and inflammation in infected cells. This combination could prevent the formation of harmful peroxynitrite, a potent pro-inflammatory substance implicated in pneumonia and COVID-19-associated organ dysfunction, as well as reduce inflammation, improve immune function, protect against free radical damage and prevent blood vessel injury. Further research is needed to fully understand the potential benefits of HXT and arginine in the context of COVID-19.

A modeling-based approach to optimize COVID-19 vaccine dosing schedules for improved protection.

While the development of different vaccines slowed the dissemination of SARS-CoV-2, the occurrence of breakthrough infections has continued to fuel the COVID-19 pandemic. To secure at least partial protection in the majority of the population through 1 dose of a COVID-19 vaccine, delayed administration of boosters has been implemented in many countries. However, waning immunity and emergence of new variants of SARS-CoV-2 suggest that such measures may induce breakthrough infections due to intermittent lapses in protection. Optimizing vaccine dosing schedules to ensure prolonged continuity in protection could thus help control the pandemic. We developed a mechanistic model of immune response to vaccines as an in silico tool for dosing schedule optimization. The model was calibrated with clinical data sets of acquired immunity to COVID-19 mRNA vaccines in healthy and immunocompromised participants and showed robust validation by accurately predicting neutralizing antibody kinetics in response to multiple doses of COVID-19 mRNA vaccines. Importantly, by estimating population vulnerability to breakthrough infections, we predicted tailored vaccination dosing schedules to minimize breakthrough infections, especially for immunocompromised individuals. We identified that the optimal vaccination schedules vary from CDC-recommended dosing, suggesting that the model is a valuable tool to optimize vaccine efficacy outcomes during future outbreaks.

Qualitative monitoring of SARS-CoV-2 mRNA vaccination in humans using droplet microfluidics.

SARS-CoV-2 mRNA vaccination generates protective B cell responses targeting the SARS-CoV-2 spike glycoprotein. Whereas anti-spike memory B cell responses are long lasting, the anti-spike humoral antibody response progressively wanes, making booster vaccinations necessary for maintaining protective immunity. Here, we qualitatively investigated the plasmablast responses by measuring from single cells within hours of sampling the affinity of their secreted antibody for the SARS-CoV-2 spike receptor binding domain (RBD) in cohorts of BNT162b2-vaccinated naive and COVID-19-recovered individuals. Using a droplet microfluidic and imaging approach, we analyzed more than 4,000 single IgG-secreting cells, revealing high interindividual variability in affinity for RBD, with variations over 4 logs. High-affinity plasmablasts were induced by BNT162b2 vaccination against Hu-1 and Omicron RBD but disappeared quickly thereafter, whereas low-affinity plasmablasts represented more than 65% of the plasmablast response at all time points. Our droplet-based method thus proves efficient at fast and qualitative immune monitoring and should be helpful for optimization of vaccination protocols.

Immune mechanisms underlying COVID-19 pathology and post-acute sequelae of SARS-CoV-2 infection (PASC).

With a global tally of more than 500 million cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections to date, there are growing concerns about the post-acute sequelae of SARS-CoV-2 infection (PASC), also known as long COVID. Recent studies suggest that exaggerated immune responses are key determinants of the severity and outcomes of the initial SARS-CoV-2 infection as well as subsequent PASC. The complexity of the innate and adaptive immune responses in the acute and post-acute period requires in-depth mechanistic analyses to identify specific molecular signals as well as specific immune cell populations which promote PASC pathogenesis. In this review, we examine the current literature on mechanisms of immune dysregulation in severe COVID-19 and the limited emerging data on the immunopathology of PASC. While the acute and post-acute phases may share some parallel mechanisms of immunopathology, it is likely that PASC immunopathology is quite distinct and heterogeneous, thus requiring large-scale longitudinal analyses in patients with and without PASC after an acute SARS-CoV-2 infection. By outlining the knowledge gaps in the immunopathology of PASC, we hope to provide avenues for novel research directions that will ultimately lead to precision therapies which restore healthy immune function in PASC patients.

A Warning on Waning: The Duration of Vaccine-Derived Immunity in Malaysia

Intro: Vaccinations have decreased the case fatality rate of COVID-19. Nonetheless, there appear to be differences in the duration of vaccine efficacy against death across populations.We aim to model the duration between vaccine type and time to death stratified by primary and booster series vaccination in Malaysia. Method(s): Data for all COVID-19 deaths between 1 February 2020 and 31 August 2022 were extracted from the Ministry of Health Malaysia data repository. Information was available on age, sex, nationality, region, vaccine status, vaccine type, and the duration from vaccination to death. The duration between primary or booster vaccination and death was modelled using Poisson regression. Finding(s): A total of 25,759 (77%), 7,421 (20%), and 1,036 (2.9%) unvaccinated, primary series vaccinated, and booster vaccinated COVID-19 deaths were respectively reported between 1 February 2020-31 August 2022 in Malaysia. The median duration between primary series vaccination and death, with AstraZeneca, Pfizer and Sinovac vaccines was respectively 150 (IQR: 73-211), 158 (IQR:88-229) and 105 (65-139) days. The median duration between booster vaccine and death with a Homologous or Heterologous vaccine was 86 (IQR: 59- 139) and 106 (66-139) days, respectively. Individuals with an AstraZeneca and Sinovac primary series had 19% (95% CI: 0.8-0.82) and 33% (95% CI: 66-0.68, p<0.01) shorter duration from vaccination to death than individuals with Pfizer vaccines. Individuals with a heterologous booster vaccination had an 8% (95% CI: 1.07-1.10, p<0.01) longer duration from vaccination to death than individuals receiving a homologous booster dose. Conclusion(s): There appear to be differences in the duration between vaccination and death by vaccine type. This must be considered alongside immune evasive variants and level of naturally acquired immunity when planning for vaccination programmes that are central to keeping COVID-19-associated mortalities low.Copyright © 2023

Can the immune system be targeted to treat COVID-19?

In COVID-19, SARS-CoV-2 has been shown to activate both innate and adaptive immune responses. However, uncontrolled or impaired immunity can lead to the development of severe forms of the disease. Understanding the underlying immunology influencing disease expression as well as the natural history of the virus is imperative to develop preventative and therapeutic strategies to tackle the COVID-19 pandemic. This chapter aims to discuss the literature surrounding the immunology of COVID-19 in a clinical context, specifically applied to the development of therapeutics and vaccines to SARS-CoV-2.Copyright © ERS 2021.