Identifying immune checkpoints on dysregulated T-cells as prognostic biomarkers for multiple myeloma patients with COVID-19.

Background: Broad T cell phenotypic alterations and potential dysfunctions were prominent in COVID-19. There are few and inconclusive data about the role of immune checkpoints for T cell exhaustion/activation during SARS-CoV-2 infection in multiple myeloma (MM) patients. Methods: We tested T cell subsets and immune checkpoints in 177 MM patients with COVID-19, as well as in 32 healthy infected controls and 42 uninfected MM patients. The percentage of CD4+ and CD8+ subpopulation and immune checkpoints (PD-1, TIGIT, TIM-3, LAG-3, CTLA-4, OX40, and 4-1BB) were evaluated by flow cytometry. Results: We have found that pronounced lymphopenia and inverted CD4/CD8 ratio in severe COVID-19 patients were especially developed within the first month after infection. And T cell subset dysregulation was persistent in severe patients recovering from SARS-CoV-2 infection. Immune checkpoints on CD4+ T cells were variable and uncorrelated with the level of adaptive immunity, while the proportion of CD4+ T cells was positively correlated with humoral immune response. PD-1 and TIGIT on CD8+ T cells were significantly elevated in severe patients and sustained for more than 2 months, which was associated with impaired cellular immune function. Moreover, exhausted molecules PD-1 and TIGIT on T cells were reduced in immunotherapy patients. Conclusion: The prolonged T cell dysregulation after severe SARS-CoV-2 infection highlights the close surveillance from reinfection in MM patients even during convalescence. PD-1 and TIGIT on CD8+ T cells could be important prognostic factors to stratify prognosis in MM patients with COVID-19. Moreover, immunotherapy may downregulate the expression of exhausted checkpoints PD-1 and TIGIT, leading to T cell overactivation and severe COVID-19.

SARS-CoV-2 spike protein induces the cytokine release syndrome by stimulating T cells to produce more IL-2.

Introduction: Cytokine release syndrome (CRS) is one of the leading causes of mortality in patients with COVID-19 caused by the SARS-CoV-2 coronavirus. However, the mechanism of CRS induced by SARS-CoV-2 is vague. Methods: Using spike protein combined with IL-2, IFN-γ, and TNF-α to stimulate human peripheral blood mononuclear cells (PBMCs) to secrete CRS-related cytokines, the content of cytokines in the supernatant was detected, and the effects of NK, T, and monocytes were analyzed. Results: This study shows that dendritic cells loaded with spike protein of SARS-CoV-2 stimulate T cells to release much more interleukin-2 (IL-2,) which subsequently cooperates with spike protein to facilitate PBMCs to release IL-1ß, IL-6, and IL-8. These effects are achieved via IL-2 stimulation of NK cells to release tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), as well as T cells to release IFN-γ Mechanistically, IFN-γ and TNF-α enhance the transcription of CD40, and the interaction of CD40 and its ligand stabilizes the membrane expression of toll-like receptor 4 (TLR4) that serves as a receptor of spike protein on the surface of monocytes. As a result, there is a constant interaction between spike protein and TLR4, leading to continuous activation of nuclear factor-κ-gene binding (NF-κB). Furthermore, TNF-α also activates NF-κB signaling in monocytes, which further cooperates with IFN-γ and spike protein to modulate NF-κB-dependent transcription of CRS-related inflammatory cytokines. Discussion: Targeting TNF-α/IFN-γ in combination with TLR4 may represent a promising therapeutic approach for alleviating CRS in individuals with COVID-19.

Cytokine landscape in hospitalized children with multisystem inflammatory syndrome.

The etiology of multisystem inflammatory syndrome in children (MIS-C), frequently observed following COVID-19 infection, remains elusive. This study unveils insights derived from cytokine analysis in the sera of MIS-C patients, both before and after the administration of intravenous immunoglobulin (IVIG) and glucocorticosteroids (GCS). In this study, we employed a comprehensive 45-cytokine profile encompassing a spectrum of widely recognized proinflammatory and antiinflammatory cytokines, as well as growth factors, along with other soluble mediators. The analysis delineates three principal cytokine-concentration patterns evident in the patients' sera. Pattern no.1 predominantly features proinflammatory cytokines (IL-6, IL-15, IL-1ra, granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor α (TNFα), C-X-C motif chemokine ligand 10 (CXCL10/ IP-10), and IL-10) exhibiting elevated concentrations upon admission, swiftly normalizing post-hospital treatment. Pattern no. 2 includes cytokines (IL-17 A, IL-33, IFNγ, vascular endothelial growth factor (VEGF), and programmed death ligand (PD-L1)) with moderately elevated levels at admission, persisting over 7-10 days of hospitalization despite the treatment. Pattern no. 3 comprises cytokines which concentrations escalated after 7-10 days of hospitalization and therapy, including IL-1α, IL-1ß, IL-2, IL-13, platelet-derived growth factor AA/BB (PDGF AA/BB). The observed in cytokine profile of MIS-C patients showed a transition from acute inflammation to sustaining inflammation which turned into induction of humoral memory mechanisms and various defense mechanisms, contributing to recovery.

Invasive Fungal Infections in Immunocompromised Conditions: Emphasis on COVID-19.

The COVID-19 pandemic caused death of 6 million lives globally, primarily from respiratory failure, but also a significant number from invasive fungal co-infections in these patients, owing to the immune dysfunction in hospitalized patients. Such complications occurred more often in critically ill, hospitalized patients particularly those admitted in intensive care units and were reported as the major reason associated with a high mortality rate worldwide. Fungal pathogens most commonly associated with COVID-19 patients comprise members of the Mucorales (such as Rhizopus, Mucor, and Lichtheimia), as well as genera Aspergillus and Candida. In India, the prevalence rate of mucormycosis is relatively high than aspergillosis and candidiasis, and the predisposing risk factors associated with such infections included uncontrolled diabetes, underlying lung disease, leukopenia, neutropenia, malignancies and prolonged steroid therapy. However, co-infection with other fungi, including Alternaria and Scedosporium was also sporadically reported. These devastating invasive fungal infections are associated with differential mortality (high-low) and morbidity rates even after active management. The diagnosis of such infections is often challenging due to lack of sensitivity in contemporary diagnostic methods and poses an enormous challenge to healthcare experts. Thus, the role of early and accurate diagnosis, and management of such fungal infections, is vital in preventing life-threatening situations. Hence, this review focusses primarily on the epidemiology, predisposing risk factors, host environment, diagnosis and treatment of the most common medically important invasive fungal infections in immunocompromised conditions associated with COVID-19.

Inactivated vaccine dosage and serum IgG levels correlate with persistent COVID-19 infections in hematologic malignancy patients during the Omicron Surge in China.

PURPOSE: The essence of this scholarly work was to carefully outline the key factors intensifying the virulence and protracted contagion of COVID-19, particularly among individuals afflicted with hematologic malignancies (HM), in an epoch predominantly governed by the Omicron variant. METHODS: Adults with HM diagnosed with COVID-19 from November 2022 to February 2023 were monitored in this retrospective study. Patient blood samples yielded biochemical data, and COVID-19 was confirmed through RNA or antigen testing. The factors affecting severity and infection duration were examined using both univariate and multivariate logistic regression analyses. For calculating the overall survival probabilities, the Kaplan-Meier product limit approach was employed. RESULTS: In the examined cohort, 133 individuals diagnosed with HM and concomitantly infected with COVID-19 were scrutinized. Of the participants, 29.3% (39 patients) were classified as Severe/Critical, while the other 70.7% (94 patients) were categorized as Non-severe. A significant difference was observed in vaccination status: 61.7% of patients in the Non-severe group had received at least a two-dose vaccine regimen, whereas 61.5% of the Severe/Critical group had either minimal or only one dose of vaccination. The data analysis revealed that elevated C-reactive protein levels (≥ 100 mg/L) significantly raised the risk of severe/critical conditions in HM patients with COVID-19, as determined by advanced multivariate logistic regression. The odds ratio was 3.415 with a 95% confidence interval of 1.294-9.012 (p = 0.013). Patients who continued to have positive nucleic acid tests and ongoing symptoms beyond 30 days were categorized as having a persistent infection, whereas those who achieved infection control within this timeframe were categorized as having infection recovery. Of the HM cohort, 11 did not survive beyond 30 days after diagnosis. The results from a competing risk model revealed that increased interleukin-6 levels (HR: 2.626, 95% CI: 1.361-5.075; p = 0.004) was significantly associated with persistent infection. Conversely, receiving more than two vaccine doses (HR: 0.366, 95% CI: 0.158-0.846; p = 0.019), and having high IgG levels (≥ 1000 mg/dl) (HR: 0.364, 95% CI: 0.167-0.791; p = 0.011), were associated with infection recovery. There was a notable disparity in survival rates between patients with persistent infections and infection recovery, with those in the non-persistent group demonstrating superior survival outcomes (P < 0.001). CONCLUSIONS: In conclusion, the study determined that HM patients with COVID-19 and increased C-reactive protein levels had a higher likelihood of severe health outcomes. Persistent infection tended to be more prevalent in those with vaccine dosages (< 2 doses), lower IgG levels, and higher interleukin-6 levels.

Detection of Neutralizing Antibodies in Serum Samples Using a SARS-CoV-2 Pseudotyped Virus Assay.

Conventional live virus research on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of coronavirus disease-19 (COVID-19), requires Biosafety Level 3 (BSL-3) facilities. SARS-CoV-2 pseudotyped viruses have emerged as valuable tools in virology, mimicking the entry process of the SARS-CoV-2 virus into human cells by expressing its spike glycoprotein in a surrogate system using recombinant plasmids. One significant application of this tool is in functional assays for the evaluation of neutralizing antibodies. Pseudotyped viruses have the advantage of being competent for only a single cycle of infection, providing better safety and versatility and allowing them to be studied in BSL-2 laboratories. Here, we describe three protocols for the detection of SARS-CoV-2 neutralizing antibodies through a pseudotyped virus assay. First, SARS-CoV-2 S pseudotyped viruses (PV SARS-CoV-2 S) are produced using a Moloney murine leukemia virus (MuLV) three-plasmid system. The plasmids are designed to express the GagPol packing proteins, enhanced green fluorescent protein (eGFP) as a readout system, and the SARS-CoV-2 S protein modified to remove the endoplasmic reticulum retention domain and to improve infection. Next, the internalization of PV SARS-CoV-2 S protein in human embryonic kidney 293T (HEK-293T) cells overexpressing angiotensin-converting enzyme 2 (HEK-293T-ACE2) is confirmed by fluorescence microscopy and quantified using flow cytometry. Finally, PV SARS-CoV-2 S is used to screen neutralizing antibodies in serum samples from convalescent COVID-19 patients; it can also be used for studying the cell entry mechanisms of different SARS-CoV-2 variants, evaluating antiviral agents, and designing vaccines. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Generation of PV SARS-CoV-2 S pseudotyped virus Basic Protocol 2: Assay of PV SARS-CoV-2 S internalization in target cells. Basic Protocol 3: Detection of neutralizing antibodies in serum samples.

Novel Compound Heterozygous Variants in the FAS Gene Lead to Fetal Onset of Autoimmune Lymphoproliferative Syndrome (ALPS).

OBJECTIVE: FAS gene defects lead to autoimmune lymphoproliferative syndrome (ALPS), which is often inherited in an autosomal dominant and rarely in an autosomal recessive manner. We report a case of a newborn girl with novel compound heterozygous variants in FAS and reveal the underlying mechanism. METHODS: Whole-exome sequencing (WES) was used to identify pathogenic variants. Multiparametric flow cytometry analysis, phosflow analysis, and FAS-induced apoptosis assays were used to explore the effects of the variants on FAS expression, apoptosis, and immunophenotype. The HEK293T cells were used to assess the impact of the variants on protein expression and FAS-induced apoptosis. RESULTS: The patient was born with hepatosplenomegaly, anemia, and thrombocytopenia. She also experienced COVID-19, rotavirus infection, herpes simplex virus infection, and severe pneumonia. The proportion of double-negative T cells (DNTs) was significantly elevated. Novel FAS compound heterozygous variants c.310T > A (p.C104S) and c.702_704del (p.T235del) were identified. The apoptotic ability of T cells was defective, and FAS expression on the surface of T cells was deficient. The T235del variant decreased FAS expression, and the C104S protein remained in the endoplasmic reticulum (ER) and could not translocate to the cell surface. Both mutations resulted in loss-of-function in terms of FAS-induced apoptosis in HEK293T cells. The DNTs were mainly terminally differentiated T (TEMRA) and CD45RA+HLA-DR+, with high expression of CD85j, PD-1, and CD57. The percentage of Th1, Tfh, and autoreactive B cells were significantly increased in the patient. The abnormal immunophenotyping was partially attenuated by sirolimus treatment. CONCLUSIONS: We identified two variants that significantly affect FAS expression or localization, leading to early disease onset of in the fetus. Abnormalities in the mTOR pathway are associated with a favorable response to sirolimus.

Lineage-specific pathogenicity, immune evasion, and virological features of SARS-CoV-2 BA.2.86/JN.1 and EG.5.1/HK.3.

SARS-CoV-2 JN.1 with an additional L455S mutation on spike when compared with its parental variant BA.2.86 has outcompeted all earlier variants to become the dominant circulating variant. Recent studies investigated the immune resistance of SARS-CoV-2 JN.1 but additional factors are speculated to contribute to its global dominance, which remain elusive until today. Here, we find that SARS-CoV-2 JN.1 has a higher infectivity than BA.2.86 in differentiated primary human nasal epithelial cells (hNECs). Mechanistically, we demonstrate that the gained infectivity of SARS-CoV-2 JN.1 over BA.2.86 associates with increased entry efficiency conferred by L455S and better spike cleavage in hNECs. Structurally, S455 altered the mode of binding of JN.1 spike protein to ACE2 when compared to BA.2.86 spike at ACE2H34, and modified the internal structure of JN.1 spike protein by increasing the number of hydrogen bonds with neighboring residues. These findings indicate that a single mutation (L455S) enhances virus entry in hNECs and increases immune evasiveness, which contribute to the robust transmissibility of SARS-CoV-2 JN.1. We further evaluate the in vitro and in vivo virological characteristics between SARS-CoV-2 BA.2.86/JN.1 and EG.5.1/HK.3, and identify key lineage-specific features of the two Omicron sublineages that contribute to our understanding on Omicron antigenicity, transmissibility, and pathogenicity.

SARS-CoV-2-Specific T-Cell as a Potent Therapeutic Strategy against Immune Evasion of Emerging COVID-19 Variants.

Despite advances in vaccination and therapies for coronavirus disease, challenges remain due to reduced antibody longevity and the emergence of virulent variants like Omicron (BA.1) and its subvariants (BA.1.1, BA.2, BA.3, and BA.5). This study explored the potential of adoptive immunotherapy and harnessing the protective abilities using virus-specific T cells (VSTs). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) VSTs were generated by stimulating donor-derived peripheral blood mononuclear cells with spike, nucleocapsid, and membrane protein peptide mixtures. Phenotypic characterization, including T-cell receptor (TCR) vß and pentamer analyses, was performed on the ex vivo-expanded cells. We infected human leukocyte antigen (HLA)-partially matched human Calu-3 cells with various authentic SARS-CoV-2 strains in a Biosafety Level 3 facility and co-cultured them with VSTs. VSTs exhibited a diverse TCR vß repertoire, confirming their ability to target a broad range of SARS-CoV-2 antigens from both the ancestral and mutant strains, including Omicron BA.1 and BA.5. These ex vivo-expanded cells exhibited robust cytotoxicity and low alloreactivity against HLA-partially matched SARS-CoV-2-infected cells. Their cytotoxic effects were consistent across variants, targeting conserved spike and nucleocapsid epitopes. Our findings suggest that third-party partial HLA-matching VSTs could counter immune-escape mechanisms posed by emerging variants of concern.

Prospective Variation of Cytokine Trends during COVID-19: A Progressive Approach from Disease Onset until Outcome.

COVID-19 is characterized by pronounced hypercytokinemia. The cytokine switch, marked by an imbalance between pro-inflammatory and anti-inflammatory cytokines, emerged as a focal point of investigation throughout the COVID-19 pandemic. However, the kinetics and temporal dynamics of cytokine release remain contradictory, making the development of new therapeutics difficult, especially in severe cases. This study collected serum samples from SARS-CoV-2 infected patients at 72 h intervals and monitored them for various cytokines at each timepoint until hospital discharge or death. Cytokine levels were analyzed based on time since symptom onset and patient outcomes. All cytokines studied prospectively were strong predictors of mortality, particularly IL-4 (AUC = 0.98) and IL-1ß (AUC = 0.96). First-timepoint evaluations showed elevated cytokine levels in the mortality group (p < 0.001). Interestingly, IFN-γ levels decreased over time in the death group but increased in the survival group. Patients who died exhibited sustained levels of IL-1ß and IL-4 and increased IL-6 levels over time. These findings suggest cytokine elevation is crucial in predicting COVID-19 mortality. The dynamic interplay between IFN-γ and IL-4 highlights the balance between Th1/Th2 immune responses and underscores IFN-γ as a powerful indicator of immune dysregulation throughout the infection.

The value of using COVID-19 antibody tests as a potential approach to prioritize vaccination delivery.

BACKGROUND: The highly contagious novel COVID-19 virus has demonstrated a great challenge for healthcare workers (HCWs) worldwide. One of these challenges is the availability of vaccines in some countries or societies, especially in the early stages of the pandemic. OBJECTIVES: This study aims to determine the level of natural immunity against COVID-19 infection among HCWs exposed to COVID-19 at the early stages of the pandemic and build a model to determine the groups that can benefit more from the scarce vaccination resources. METHODS: This study took place between January and March 2021, after the first waves of the COVID-19 pandemic, before spreading the variants of concern, such as the UK variant (Alpha B.1.1.7), and before starting the vaccine campaigns. This cross-sectional study collected serum samples from 251 vulnerable HCWs. The samples were tested for IgG antibodies against COVID-19 using commercial kits. The demographics and clinical characteristics of the participants were recorded using face-to-face interviews. RESULTS: COVID-19 IgG antibodies were detected in more than 40% of HCWs before vaccination. Those HCWs should have less priority than those without COVID-19 IgG. The seroprevalence of COVID-19 was higher in male HCWs and among nurses. There was no association between the participants' immunity and smoking status or different blood groups. Most HCWs reported being infected with the virus during the first wave, mainly at the end of 2020. A limited number of HCWs reported infections between January 2021 and March 2021. All HCWs eventually received the COVID-19 vaccine, ignoring being previously infected. CONCLUSION: The reported results emphasize the value of using immunity tests to prioritize the groups that may benefit the most from the limited vaccines, especially in developing countries with scarce resources where those with COVID-19 IgG antibodies should have less priority for the COVID-19 vaccine. The present results indicate that up to 40% of the delivered vaccines to HCWs who had COVID-19 antibodies could be prioritized more wisely in future pandemics.

Safety and efficacy of COVID-19 vaccines in children and adolescents with cancer.

BACKGROUND: Children with cancer have a higher morbidity and mortality due to COVID-19. Vaccination of children with cancer is important. In this study, we aimed to investigate the effectiveness and side effects of the COVID-19 vaccines in children and adolescents with cancer. METHODS: Fifty-eight patients from four centers were included in the study. Antibodies to the SARS-CoV-2 spike protein levels were measured. Vaccine-related complaints were recorded. RESULTS: There were 33 male and 25 female patients. The mean age was 16.9±2.3 years. In 58.6% of cases, the diagnosis was hematological malignancies. Twenty patients were currently under treatment, while 38 had completed the treatment. Forty-eight patients received chemotherapy ± radiotherapy, 13 received immunotherapy, and 3 underwent stem cell transplantation. CoronoVac© and BNT162b2© vaccines were administered in 24% and 76%, respectively. The mean antibody level was lower in patients who received CoronaVac© than that of BNT162b2©, although the difference was not significant. The levels were within the protective limits in both groups. No significant difference was found in antibody levels according to diagnostic subgroups, treatment status, type of treatment, line of treatment, disease status and time between vaccines and measurement of antibody level. The most common side effects were pain at the injection site (37.9%) and malaise/weakness (17.2%), which were similar for both vaccines. CONCLUSIONS: Our study showed that both mRNA and inactivated vaccines elicit an immune response in children with cancer. However, the seroconversion rate is significantly higher in mRNA vaccines. Side effects were similar to those seen in healthy children.

Design of the conserved epitope peptide of SARS-CoV-2 spike protein as the broad-spectrum COVID-19 vaccine.

Our previous study has found that monoclonal antibodies targeting a conserved epitope peptide spanning from residues 1144 to 1156 of SARS-CoV-2 spike (S) protein, namely S(1144-1156), can broadly neutralize all of the prevalent SARS-CoV-2 strains, including the wild type, Alpha, Epsilon, Delta, and Gamma variants. In the study, S(1144-1156) was conjugated with bovine serum albumin (BSA) and formulated with Montanide ISA 51 adjuvant for inoculation in BALB/c mice to study its potential as a vaccine candidate. Results showed that the titers of S protein-specific IgGs and the neutralizing antibodies in mouse sera against various SARS-CoV-2 variants, including the Omicron sublineages, were largely induced along with three doses of immunization. The significant release of IFN-γ and IL-2 was also observed by ELISpot assays through stimulating vaccinated mouse splenocytes with the S(1144-1156) peptide. Furthermore, the vaccination of the S(1143-1157)- and S(1142-1158)-EGFP fusion proteins can elicit more SARS-CoV-2 neutralizing antibodies in mouse sera than the S(1144-1156)-EGFP fusion protein. Interestingly, the antisera collected from mice inoculated with the S(1144-1156) peptide vaccine exhibited better efficacy for neutralizing Omicron BA.2.86 and JN.1 subvariants than Omicron BA.1, BA.2, and XBB subvariants. Since the amino acid sequences of the S(1144-1156) are highly conserved among various SARS-CoV-2 variants, the immunogen containing the S(1144-1156) core epitope can be designed as a broadly effective COVID-19 vaccine. KEY POINTS: • Inoculation of mice with the S(1144-1156) peptide vaccine can induce bnAbs against various SARS-CoV-2 variants. • The S(1144-1156) peptide stimulated significant release of IFN-γ and IL-2 in vaccinated mouse splenocytes. • The S(1143-1157) and S(1142-1158) peptide vaccines can elicit more SARS-CoV-2 nAbs in mice.

Immunomodulatory effect of IFN-γ licensed adipose-mesenchymal stromal cells in an in vitro model of inflammation generated by SARS-CoV-2 antigens.

In recent years, clinical studies have shown positive results of the application of Mesenchymal Stromal Cells (MSCs) in severe cases of COVID-19. However, the mechanisms of immunomodulation of IFN-γ licensed MSCs in SARS-CoV-2 infection are only partially understood. In this study, we first tested the effect of IFN-γ licensing in the MSC immunomodulatory profile. Then, we established an in vitro model of inflammation by exposing Calu-3 lung cells to SARS-CoV-2 nucleocapsid and spike (NS) antigens, and determined the toxicity of SARS-CoV-2 NS antigen and/or IFN-γ stimulation to Calu-3. The conditioned medium (iCM) generated by Calu-3 cells exposed to IFN-γ and SARS-CoV-2 NS antigens was used to stimulate T-cells, which were then co-cultured with IFN-γ-licensed MSCs. The exposure to IFN-γ and SARS-CoV-2 NS antigens compromised the viability of Calu-3 cells and induced the expression of the inflammatory mediators ICAM-1, CXCL-10, and IFN-ß by these cells. Importantly, despite initially stimulating T-cell activation, IFN-γ-licensed MSCs dramatically reduced IL-6 and IL-10 levels secreted by T-cells exposed to NS antigens and iCM. Moreover, IFN-γ-licensed MSCs were able to significantly inhibit T-cell apoptosis induced by SARS-CoV-2 NS antigens. Taken together, our data show that, in addition to reducing the level of critical cytokines in COVID-19, IFN-γ-licensed MSCs protect T-cells from SARS-CoV-2 antigen-induced apoptosis. Such observations suggest that MSCs may contribute to COVID-19 management by preventing the lymphopenia and immunodeficiency observed in critical cases of the disease.

The winding road: Infectious disease considerations for CAR-T and other novel adoptive cellular therapies in the era of COVID-19.

Adoptive cellular therapies (ACT) are novel, promising treatments for life-threatening malignancies. In addition to the better known chimeric antigen receptor (CAR) T cells, ACTs include tumor infiltrating lymphocytes (TIL), cancer antigen-specific T cell receptors (TCRs), and CAR-NK (natural killer) cells. In key historic milestones, several adoptive therapies recently received FDA approvals, including 6 CAR-T products for the treatment of hematologic malignancies and the first TIL therapy for the treatment for metastatic melanoma. The rapid pace of clinical trials in the field and the discoveries they provide are ushering in a new era of cancer immunotherapy. However, the potential complications of these therapies are still not fully understood. In particular, patients receiving ACT may be at increased risk for severe infections due to immunocompromise resulting from their underlying malignancies, which are further compounded by the immune derangements that develop in the setting of cellular immunotherapy and/or the preconditioning treatment needed to enhance ACT efficacy. Moreover, these treatments are being readily implemented at a time following the height of the COVID-19 pandemic, and it remains unclear what additional risks these patients may face from SARS-CoV-2 and similar infections. Here, we examine the evidence for infectious complications with emerging adoptive therapies, and provide a focused review of the epidemiology, complications, and clinical management for COVID-19 in CAR-T recipients to understand the risk this disease may pose to recipients of other forms of ACT.

T-Cell Receptors Cross-Reactive to Coronaviral Epitopes Homologous to the SPR Peptide.

The COVID-19 pandemic caused by the rapid spread of the novel coronavirus SARS-CoV-2, has promoted an interest in studying the T-cell immune response. It was found that the polyclonal and cross-reactive T-cell response against seasonal coronaviruses and other SARS-CoV-2 strains reduced disease severity. We investigated the immunodominant T-cell epitope SPRWYFYYYL from the nucleocapsid protein of SARS-CoV-2. The immune response to this epitope is characterized by the formation of highly homologous (convergent) receptors that have been found in the T-cell receptor (TCR) repertoires of different individuals. This epitope belongs to a group of highly conserved peptides that are rarely mutated in novel SARS-CoV-2 strains and are homologous to the epitopes of seasonal coronaviruses. It has been suggested that the cross-reactive response to homologous peptides contributes to the reduction of COVID-19 severity. However, some investigators have questioned this hypothesis, suggesting that the low affinity of the cross-reactive receptors reduces the strength of the immune response. The aim of this study was to evaluate the effect of amino acid substitutions in the SPR epitope on its binding affinity to specific TCRs. For this, we performed antigen-dependent cellular expansions were performed using samples from four COVID-19-transfected donors and sequenced their TCR repertoires. The resulting SPR-specific repertoire of ß-chains in TCRs had a greater sequence diversity than the repertoire of α-chains. However, the TCR repertoires of all four donors contained public receptors, three of which were cloned and used to generate the Jurkat E6-1 TPR cell line. Only one of these receptors was activated by the SPR peptide and recognized with the same affinity by its mutant homologue LPRWYFYYY from seasonal coronaviruses. This indicates that the presence of the mutation did not affect the strength of the immune response, which may explain why the cross-reactive response to the SPR epitope is so frequent and contributes positively to COVID-19 infection.

The SARS-unique domain (SUD) of SARS-CoV-2 nsp3 protein inhibits the antiviral immune responses through the NF-κB pathway.

Nuclear factor κB (NF-κB) plays a crucial role in various cellular processes, including inflammatory and immune responses. Its activation is tightly regulated by the IKK (IκB kinase) complex. Upon severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the virus is initially recognized by the innate immune system and typically activates the NF-κB pathway, leading to a severe inflammatory response. However, the influence of viral proteins upon pro-inflammatory pathway is complicated. Here, we demonstrated that the viral protein nsp3 of SARS-CoV-2 exhibits an unusual function, which attenuated the NF-κB-mediated inflammatory response against SARS-CoV-2 infection in a unique manner. nsp3 interacted with the essential NF-κB modulator NEMO/IKKγ and promoted its polyubiquitylation via the E3 ubiquitin ligase CBL (Cbl Proto-Oncogene). Consequently, polyubiquitylated NEMO undergoes proteasome-dependent degradation, which disrupts NF-κB activation. Moreover, we found that the SARS unique domain (SUD) in nsp3 of SARS-CoV-2 is essential for inducing NEMO degradation, whereas this function is absent in SUD of SARS-CoV. The reduced activation of pro-inflammatory response at an early stage could mask the host immune response and faciliate excessive viral replication. Conversely, this finding may partially explain why SARS-CoV-2 causes a less inflammatory reaction than SARS-CoV, resulting in more mild or moderate COVID-19 cases and greater transmissibility. Given that NEMO is important for NF-κB activation, we propose that inhibiting polyubiquitylation and degradation of NEMO upon SARS-CoV-2 infection is a novel strategy to modulate the host inflammatory response.

Nationwide Cohort observational study on the safety and efficacy of COVID-19 vaccination in patients with Moyamoya disease.

The safety and efficacy of coronavirus disease 2019 (COVID-19) vaccination in patients diagnosed with Moyamoya disease (MMD) have not been established. Using National Health Insurance Service data, this study analyzed the occurrence of stroke-related events and mortality following COVID-19 vaccination among patients diagnosed with MMD from 2008 to 2020. Among 10,297 MMD patients, 296 (2.9%) experienced events and 175 (1.7%) died in 2021. Significant risk factors for events included ages 50-59 (Odds Ratio [OR] 3.29; P = 0.022) and 60 or above (OR 5.20; P = 0.001) (reference group: age in 20s), low BMI (OR 2.00; P = 0.011), previous stroke (OR 1.96; P < 0.001), and COVID-19 infection (OR 2.28; P = 0.034). Female (OR 0.64 [95% CI 0.50-0.82]; p = 0.011), revascularization surgery (RS) (OR 0.38 [95% CI 0.21-0.70]; p < 0.001), and vaccination (OR 0.17 [95% CI 0.13-0.22]; p < 0.001) were associated with reduced odds of stroke-related events. For mortality, significant risks were age over 60 (OR 7.09; P = 0.008), low BMI (OR 3.87; P = 0.001), and prior stroke (OR 1.74; p = 0.004), while being female, RS (OR 0.41; P = 0.022), and vaccination (OR 0.12; P < 0.001) were associated with a lower frequency of mortality. mRNA vaccines were associated with a significantly lower incidence of events, mortality, and COVID-19 infections compared to vector vaccines. COVID-19 vaccination is linked to reduced stroke-related events and mortality in MMD patients, with mRNA vaccines showing a significantly lower incidence compared to vector vaccines. COVID-19 infection raises the risk of events, underscoring the benefit of vaccination.

Systematic review and meta analysis of cross immunity and the smokers paradox in COVID19.

COVID-19 pandemic, caused by the novel SARS-CoV-2 virus, has raised significant interest in understanding potential cross-immunity mechanisms. Recent evidence suggests that T-cells associated with common cold coronaviruses (229E, NL63, OC43, HKU1) may provide some level of cross-immunity against SARS-CoV-2. It is also known that the prevalence of smokers among patients admitted to hospital for COVID-19 is lower than expected according to the corresponding country's smoking prevalence, which is known as smoker's paradox in COVID-19. No clear consensus to explain it has yet been reached. This phenomenon suggests a complex interaction between smoking and immune response. Nonetheless, very few works have studied the prevalence of smokers in those infected by common cold coronaviruses, and its relation to COVID-19 has not been investigated. We performed a systematic review and meta-analysis to study the prevalence of smokers among patients infected by common cold coronaviruses, and to compare them to the corresponding country's smoking prevalence. L'Abbé plots were used to visually assess the consistency of the observed effects across the different studies included in the meta-analysis. Additionally, significant differences were found in smoking prevalence among the various types of ccCoV, indicating the need for further research into the biological mechanisms driving these disparities. The results show that smoking prevalence is higher among those patients infected by these coronaviruses than in the general population (OR = 1.37, 95% CI: 0.81-2.33). A study was separately done for the four coronavirus types, and the prevalence of smokers was higher in three of the four than that corresponding to country, gender and study year: OC43 (OR = 1.93, 95% CI: 0.64-5.82); HKU1 (OR = 3.62, 95% CI: 1.21-10.85); NL63 (OR = 1.93, 95% CI: 0.64-5.82); 229E (OR = 0.97, 95% CI: 0.50-1.90). The heterogeneity of the studies was assessed using the Cochrane Chi-squared test, I-squared (I2), and Tau-squared (τ2). This detailed statistical analysis enhances the robustness of our findings and highlights the variations in smoking prevalence among different ccCoVs. Our data suggest that COVID-19 might be less prevalent among smokers due to greater cross-immunity from a larger number or more recent infections by common cold coronaviruses than the non-smoking population, which would explain smoker's paradox in COVID-19. IMPLICATIONS. The low prevalence of current smokers among SARS-CoV-2 patients is a finding recurrently repeated, even leading to postulate the "smoker's paradox" in COVID-19. This fact compelled us to study the prevalence of smokers among patients infected by common cold coronaviruses, and to compare them to the corresponding country's smoking prevalence. Our data could explain smoker's paradox in COVID-19 by a greater cross immunity due to a larger number, or more recent infections by common cold coronaviruses than the non-smoking population. This manuscript allow understand potential unrevealed mechanism for low prevalence of current smokers among SARS-CoV-2 patients.

Do immunosuppressive treatments influence immune responses against adenovirus-based COVID-19 vaccines in patients with multiple sclerosis? An Argentine multicenter study.

Introduction: There are no reports in LATAM related to longitudinal humoral and cellular response to adenovirus based COVID-19 vaccines in people with Multiple Sclerosis (pwMS) under different disease modifying therapies (DMTs) and neutralization of the Omicron and Wuhan variants of SARS-COV-2. Methods: IgG anti- SARS-COV-2 spike titer were measured in a cohort of 101 pwMS under fingolimod, dimethyl fumarate, cladribine and antiCD20, as well as 28 healthy controls (HC) were measured 6 weeks after vaccination with 2nd dose (Sputnik V or AZD1222) and 3nd dose (homologous or heterologous schedule). Neutralizing capacity was against Omicron (BA.1) and Wuhan (D614G) variants and pseudotyped particles and Cellular response were analyzed. Results: Multivariate regression analysis showed anti-cd20 (ß= -,349, 95% CI: -3655.6 - -369.01, p=0.017) and fingolimod (ß=-,399, 95% CI: -3363.8 - -250.9, p=0.023) treatments as an independent factor associated with low antibody response (r2 adjusted=0.157). After the 2nd dose we found a correlation between total and neutralizing titers against D614G (rho=0.6; p<0.001; slope 0.8, 95%CI:0.4-1.3), with no differences between DMTs. Neutralization capacity was lower for BA.1 (slope 0.3, 95%CI:0.1-0.4). After the 3rd dose, neutralization of BA.1 improved (slope: 0.9 95%CI:0.6-1.2), without differences between DMTs. A fraction of pwMS generated anti-Spike CD4+ and CD8+ T cell response. In contrast, pwMS under antiCD20 generated CD8+TNF+IL2+ response without differences with HC, even in the absence of humoral response. The 3rd dose significantly increased the neutralization against the Omicron, as observed in the immunocompetent population. Discussion: Findings regarding humoral and cellular response are consistent with previous reports.