Immunotherapy: ALLOGENEIC UMBILICAL CORD BLOOD REGULATORY T CELLS DECREASE INFLAMMATION AND PRESERVE ANTI-TUMOR ACTIVITY OF CAR T CELLS

Background & Aim: With larger accessibility and increased number of patients being treated with CART cell therapy, real-world toxicity continues to remain a significant challenge to its widespread adoption. We have previously shown that allogeneic umbilical cord blood derived (UCB) regulatory T cells (Tregs) can resolve uncontrolled inflammation and can treat acute and immune mediated lung injury in a xenogenic model as well as in patients suffering from COVID-19 acute respiratory distress syndrome. The unique properties of UCB Tregs including: i) lack of plasticity when exposed to inflammatory micro-environments;ii) no requirement for HLA matching;iii) long shelf life of cryopreserved Tregs;and iv) immediate product availability for on demand treatment, makes them an attractive source for treating acute inflammatory syndromes. Therefore, we hypothesized that add-on therapy with UCB derived Tregs may resolve uncontrolled inflammation responsible for CART cell therapy associated toxicity. Methods, Results & Conclusion(s): UCB Tregs were added in 1:1 ratio to CART cells, where no interference in their ability to kill CD19+ Raji cells, was detected at different ratios : 8:1 (80.4% vs. 81.5%);4:1 (62.0% vs. 66.2%);2:1 (50.1% vs. 54.7%);1:1 (35.4% vs. 44.1%) (Fig 1A). In a xenogenic B cell lymphoma model, multiple injections of Tregs were administered after CART injection (Fig 1B), which did not impact distribution of CD8+ T effector cells (Fig 1C) or CART cells cells (Fig 1D) in different organs. No decline in the CAR T levels was observed in the Tregs recipients (Fig 1E). Specifically, no difference in tumor burden was detected between the two arms (Fig 2A). No tumor was detected in CART+Tregs in liver (Fig 2B) or bone marrow (Fig 2C). A corresponding decrease in multiple inflammatory cytokines in peripheral blood was observed in CART+Tregs when compared to CART alone (Fig 2D). Here we show "proof of concept" for add-on therapy with Tregs to mitigate hyper-inflammatory state induced by CART cells without interference in their on-target anti-tumor activity. The timing of Tregs administration after CART cells have had sufficient time for forming synapse with tumor cells allows for preservation of their anti-tumor cytotoxicity, such that the infused Tregs home to the areas of tissue damage to bind to the resident antigen presenting cells which in turn collaborate with Tregs to resolve inflammation. Such differential distribution of cells allow for a Treg "cooling blanket" and lays ground for clinical study. [Figure presented]Copyright © 2023 International Society for Cell & Gene Therapy

Optimizing mRNA vaccines and virusmediated CAR T-cell therapy for immuno-oncology: Synthetic tools for gene modification

With the success of mRNA vaccines during the COVID-19 pandemic and CAR T-cell therapies in clinical trials, there is growing opportunity for immunotherapies in the treatment of many types of cancers. Lentiviral vectors have proven effective at delivery of genetic material or gene editing technology for ex vivo processing, but the benefits and promise of Adeno-associated virus (AAV) and mRNA tools for in vivo immunotherapy have garnered recent interest. Here we describe complete synthetic solutions for immuno-oncology research programs using either mRNA-vaccines or virus-mediated cell and gene engineering. These solutions optimize workflows to minimize screening time while maximizing successful research results through: (1) Efficiency in lentiviral packaging with versatility in titer options for high-quality particles. (2) A highthroughput viral packaging process to enable rapid downstream screening. (3) Proprietary plasmid synthesis and preparation techniques to maintain ITR integrity through AAV packaging and improve gene delivery. (4) Rapid synthesis, in vitro transcription, and novel sequencing of mRNA constructs for complete characterization of critical components such as the polyA tail. The reported research demonstrates a streamlined approach that improves data quality through innovative synthesis and sequencing methodologies as compared to current standard practices.

A retrospective observational study of CAR T-cell therapy outcomes-Experience from MSE Foundation Trust

The most common non-Hodgkin's lymphoma (NHL) is diffuse large B-cell lymphoma (DLBCL), an aggressive lymphoma that can be cured with standard frontline chemo-immunotherapy in 60%-70% of patients but with historically poor outcomes for relapsed/refractory disease. Patients with relapsed DLBCL after autologous stem cell transplant (ASCT) or with chemotherapy-refractory disease have a particularly dismal prognosis, with a median overall survival (OS) of only 6 months. Chimeric antigen receptor (CAR) T-cell therapy has significantly improved outcomes for patients with relapsed/refractory large B-cell lymphoma, mantle cell lymphoma and follicular lymphoma, with multiple FDA approved CAR T products now commercially available in many developed world including European countries. Ongoing studies seek to move CAR T cells to earlier lines of therapy and to characterise the efficacy and safety of CAR T-cell approaches in additional lymphoma histologies including relapsed/refractory follicular lymphoma and chronic lymphocytic leukaemias. Other areas of active research address CAR T in combination with other lymphoma-directed therapies, and mechanisms of CAR T resistance. We conducted a retrospective observational study assessing the outcomes of patients referred to our tertiary centre, University College London hospital NHS foundation Trust (UCLH) from January 2018 to December 2022, over a 48-month period. We collected data including patients' demographics, types of lymphomas, prior lines of therapies including stem cell transplantation, bridging therapies as appropriate, complications and overall response rate. We also analysed the communication between teams during the challenging period of the COVID-19 pandemic.

Expansion of human T cells using xenogeneic free and gamma irradiated human platelet lysate

Commercially available human platelet lysate (hPL) is produced using expired human platelets obtained from accredited blood banks in the United States. These platelets were originally intended for use in patient transfusion. The safety of platelets used in transfusion is managed by the U.S. Food Drug Administration (FDA), as well as the American Association of Blood Banks (AABB). These organizations set standards, including testing for transmissible diseases. The United States record for blood safety is well established, with extremely low rates of disease transmission, making the platelet units used for hPL manufacture low risk. The Covid-19 pandemic has increased awareness of emerging infectious diseases, even though transmission of Covid-19 via blood transfusion has not been documented. For that reason, gamma irradiated hPL offers an additional safety measure in the clinic. Chimeric Antigen Receptor (CAR) expressing T-cells have demonstrated potent clinical efficacy in patients with hematological malignancies. In addition, there are several phase I clinical trials evaluating the use of CAR-T-cells for targeting of solid tumorassociated antigens. Some of the challenging issues found during production of CAR-T cells are the efficiency of T cell transduction to generate CAR-T cells, the expansion of T cells to clinically relevant numbers and the long-term survival in vivo of the therapeutic cells. The use of human platelet lysate has been demonstrated to improve these issues. Our data from experiments performed using human CD3+ from donors demonstrates that human platelet lysates offer an improved performance on T cell expansion versus serum derived products. hPL efficiently promotes T cell expansion, with higher cell yields and lower cell exhaustion rate. Additionally, we efficiently developed a protocol for suspension culture of T cells, which could facilitate the large-scale expansion of allogeneic CAR-T cells.

Virus-like Particle Vaccines and Platforms for Vaccine Development.

Virus-like particles (VLPs) have gained a lot of interest within the past two decades. The use of VLP-based vaccines to protect against three infectious agents-hepatitis B virus, human papillomavirus, and hepatitis E virus-has been approved; they are very efficacious and offer long-lasting immune responses. Besides these, VLPs from other viral infectious agents (that infect humans, animals, plants, and bacteria) are under development. These VLPs, especially those from human and animal viruses, serve as stand-alone vaccines to protect against viruses from which the VLPs were derived. Additionally, VLPs, including those derived from plant and bacterial viruses, serve as platforms upon which to display foreign peptide antigens from other infectious agents or metabolic diseases such as cancer, i.e., they can be used to develop chimeric VLPs. The goal of chimeric VLPs is to enhance the immunogenicity of foreign peptides displayed on VLPs and not necessarily the platforms. This review provides a summary of VLP vaccines for human and veterinary use that have been approved and those that are under development. Furthermore, this review summarizes chimeric VLP vaccines that have been developed and tested in pre-clinical studies. Finally, the review concludes with a snapshot of the advantages of VLP-based vaccines such as hybrid/mosaic VLPs over conventional vaccine approaches such as live-attenuated and inactivated vaccines.

Respiratory Viral Infections in Recipients of Cellular Therapies: A Review of Incidence, Outcomes, Treatment, and Prevention.

Respiratory viral infections (RVIs) are of major clinical importance in immunocompromised patients and represent a substantial cause of morbidity and mortality in patients with hematologic malignancies and those who have undergone hematopoietic cell transplantation. Similarly, patients receiving immunotherapy with CD19-targeted chimeric antigen receptor-modified T cells, natural killer cells, and genetically modified T-cell receptors are susceptible to RVIs and progression to lower respiratory tract infections. In adoptive cellular therapy recipients, this enhanced susceptibility to RVIs results from previous chemotherapy regimens such as lymphocyte-depleting chemotherapy conditioning regimens, underlying B-cell malignancies, immune-related toxicities, and secondary prolonged, profound hypogammaglobulinemia. The aggregated risk factors for RVIs have both immediate and long-term consequences. This review summarizes the current literature on the pathogenesis, epidemiology, and clinical aspects of RVIs that are unique to recipients of adoptive cellular therapy, the preventive and therapeutic options for common RVIs, and appropriate infection control and preventive strategies.

Modeling the Tumor Microenvironment and Cancer Immunotherapy in Next-Generation Humanized Mice.

Cancer immunotherapy has brought significant clinical benefits to numerous patients with malignant disease. However, only a fraction of patients experiences complete and durable responses to currently available immunotherapies. This highlights the need for more effective immunotherapies, combination treatments and predictive biomarkers. The molecular properties of a tumor, intratumor heterogeneity and the tumor immune microenvironment decisively shape tumor evolution, metastasis and therapy resistance and are therefore key targets for precision cancer medicine. Humanized mice that support the engraftment of patient-derived tumors and recapitulate the human tumor immune microenvironment of patients represent a promising preclinical model to address fundamental questions in precision immuno-oncology and cancer immunotherapy. In this review, we provide an overview of next-generation humanized mouse models suitable for the establishment and study of patient-derived tumors. Furthermore, we discuss the opportunities and challenges of modeling the tumor immune microenvironment and testing a variety of immunotherapeutic approaches using human immune system mouse models.

Prophylactic Corticosteroid Use with Axicabtagene Ciloleucel (Axi-Cel) in Patients (Pts) with Relapsed/ Refractory Large B-Cell Lymphoma (R/R LBCL): 2-Year Follow-up of Zuma-1 Cohort 6

Background: The ZUMA-1 safety management Cohort 6 (N=40), which evaluated whether prophylactic corticosteroids and earlier corticosteroids and/or tocilizumab could improve safety outcomes, demonstrated an improved safety profile (no Grade >=3 cytokine release syndrome [CRS];15% Grade >=3 neurologic events [NEs]) vs pivotal Cohorts 1+2, without compromising response rate or durability (95% ORR, 80% CR rate, and 53% ongoing response rate with >=1 y of follow-up;Oluwole, et al. ASH 2021. 2832). Here, 2-y updated outcomes are reported. Method(s): Eligible pts with R/R LBCL underwent leukapheresis (followed by optional bridging therapy) and conditioning chemotherapy, then a single axi-cel infusion. Pts received corticosteroid prophylaxis (once-daily oral dexamethasone 10 mg on Days 0 [before axi-cel], 1, and 2) and earlier corticosteroids and/or tocilizumab for CRS and NE management vs Cohorts 1+2 (Oluwole, et al. Br J Haematol. 2021). The primary endpoints were incidence and severity of CRS and NEs. Secondary endpoints included ORR (investigator-assessed), duration of response (DOR), progression-free survival (PFS), overall survival (OS), and chimeric antigen receptor (CAR) T-cell levels in blood. Result(s): As of December 16, 2021, the median follow-up time for the 40 treated pts was 26.9 mo. Since the 1-y analysis, no new CRS events were reported (no pts had Grade >=3 CRS to date). The incidence of Grade >=3 NEs increased from 15% to 18%between the 1-y and 2-y analyses. Two new NEs occurred in 2 pts: 1 pt had Grade 2 dementia (onset on Day 685 and ongoing at time of data cutoff;not related to axi-cel) and 1 had Grade 5 axi-cel-related leukoencephalopathy. Since the 1-y analysis, 6 new infections were reported (Grades 1, 2, and 5 COVID-19 [n=1 each], Grade 3 Pneumocystis jirovecii pneumonia [n=1], Grade 3 unknown infectious episode with inflammatory syndrome [n=1], and Grade 2 herpes zoster [n=1]). In total, 8 deaths occurred since the 1-y analysis (progressive disease [n=5], leukoencephalopathy [n=1], and COVID-19 [n=2]). The ORR was 95% (80% CR), which was unchanged from the 1-y analysis. Median DOR and PFS were since reached (25.9 mo [95% CI, 7.8-not estimable] and 26.8 mo [95% CI, 8.7-not estimable], respectively). Median OS was still not reached. Kaplan- Meier estimates of the 2-y DOR, PFS, and OS rates were 53%, 53%, and 62%, respectively. Of 18 pts (45%) in ongoing response at data cutoff, all achieved CR as the best response. By Month 24, 14/20 pts with evaluable samples (70%) had detectable CAR T cells (vs 23/36 pts [64%] in Cohorts 1+2). Conclusion(s): With 2 y of follow-up, the ZUMA-1 Cohort 6 toxicity management strategy continued to demonstrate an improved long-term safety profile of axi-cel in pts with R/R LBCL. Further, responses remained high, durable, and similar to those observed in Cohorts 1+2 (Locke, et al. Lancet Oncol. 2019).Copyright © 2023 American Society for Transplantation and Cellular Therapy

Anaphylaxis to Cyclophosphamide Metabolites during Lymphodepletion for CAR-T Therapy

Background: Cyclophosphamide (Cy) is used in hematopoietic stem cell transplant (HSCT) preparative regimens and lymphodepletion for chimeric antigen receptor T-cell (CAR-T) therapy. We describe a case of cyclophosphamide hypersensitivity in a pediatric patient during CAR-T therapy. Case description: A 13 year old boy was diagnosed with very high risk ALL in 2015 and had 2 isolated CNS relapses treated with intensified chemotherapy (chemo) and cranial radiation (1st relapse) and Blinatumomab with intrathecal (IT) chemo followed by sibling donor HSCT (2nd relapse). At age 19, and 18 months after HSCT, he had a 3rd CNS relapse treated with IT chemo and referral for CAR-T therapy. At our center, leukapheresis and CAR-T production (Novartis) were performed. Later, during lymphodepletion with fludarabine (Flu) and Cy, physiologic replacement hydrocortisone (HC) was briefly held to prevent interference with CAR-T function. After 3 days of Flu/Cy, he developed fever and hypotension requiring inotropic support. Hypotension and fever resolved with stress dose HC and antibiotics and was attributed to culture-negative sepsis and adrenal crisis. CAR-T infusion was subsequently delayed by skin GVHD requiring glucocorticoids and COVID-19 infection treated with convalescent plasma and nirmatrelvir/ritonavir. Physiologic HC replacement was continued when he was re-admitted for CAR-T therapy, but he again developed fever, diffuse erythema and shock in hours following the first dose of Cy necessitating stress dose HC, antibiotics, inotropes, and mechanical ventilation. Negative blood cultures and ongoing physiologic HC replacement suggested an alternative explanation for shock. Case reports of anaphylaxis to Cy metabolites implicated Cy as the causative agent so it was discontinued. After recovery, CAR-T cells were infused without complications. In the following weeks, he had no evidence of recurrent leukemia but was persistently pancytopenic. A sibling donor stem cell boost was proposed but the patient accepted only palliative care. He had several opportunistic infections before succumbing to E. coli sepsis. Discussion(s): The first episode of shock was initially attributed to adrenal crisis and sepsis, although no organism was identified. The second episode appeared anaphylactic in timing and clinical presentation with adequate HC replacement and negative cultures, suggesting Type I hypersensitivity. The patient previously received Cy uneventfully before HSCT, suggesting that the donor-derived immune system was the source of new Cy hypersensitivity. Onset of anaphylaxis within hours rather than minutes after Cy administration supports hypersensitivity to Cy metabolites rather than to the drug itself. This case highlights the importance of consideration of sensitivity to Cy metabolites as well as acquired donor-specific allergy even when alternative explanations are likely.Copyright © 2023 American Society for Transplantation and Cellular Therapy

Outcomes for Anti-CD19+ Chimeric Antigen Receptor T (CAR-T) Cell Therapy for Non Hodgkin Lymphoma (NHL) across a Large Community Transplant and Cellular Therapy Network

Background: The Sarah Cannon Transplant and Cellular Therapy Network (SCTCTN), which offers community access to transplant and cell therapy, implemented a coordinated approach to deliver CAR-T therapy through 5 programs. We conducted a retrospective review of clinical outcomes after FDA-approved anti-CD19+ CAR-T in B-cell NHL. Method(s): All patients referred for evaluation within SCTCTN were tracked in our prospective registry (Stafa-CT). We identified 110 patients who received FDA-approved anti-CD19+ CAR-T for NHL within the network between 12/10/2018 and 3/7/2022. All patients received care through standardized eligibility criteria, process, care pathways, toxicity management protocols, and a single quality plan. Result(s): The median age at referral was 60 years (range 23-82), 63% were male, the referral indication was diffuse large B-cell lymphoma (70%), mantle cell lymphoma (7%), follicular lymphoma (15%), or other B-NHL (8%). 35% had received a prior autologous transplant. The median time from referral to infusion was 143 days (range 89- 224), and from collection to infusion was 32 days. The infusion year was 2018 (1), 2019 (20), 2020 (31), 2021 (48), 2022 (10). The CAR-T cell products were Axi-cel (70), Tisa-cel (27), Brexu-cel (9), and Liso-cel (4). 16 patients (15%) were infused as outpatient, of which 10 patients were subsequently hospitalized at a median of 8 days (range 1-26) after infusion. Of the 94 patients (85%) infused as inpatient, the median length of stay was 15 days (range 6 to 85). Cytokine release syndrome (CRS) was observed in 78% with a median maximum grade 1. Maximum grade CRS was none, grade 1, grade 2, grade 3, grade 4, grade 5 in 22%, 36%, 32%, 7%, 2 % and <1%, respectively. The median times to onset and resolution of symptoms were day 3 and 8, respectively. Tocilizumab was administered to 39% for a median of 2 doses. Neurotoxicity was observed in 55% with a median maximum grade 1. Maximum grade neurotoxicity was none, grade 1, grade 2, grade 3, grade 4, grade 5 in 45%, 19%, 13%, 18%, 4 % and 0%, respectively. The median times to onset and resolution of symptoms were day 7 and 13, respectively. Neutropenia (<0.5/ muL) and thrombocytopenia (<20K/muL) at day 30 were reported in 11% and 12%, respectively. 18% required ICU stay. 37 deaths (34%) were reported from disease progression (23), infections (7, including 5 from COVID), CRS (2) and other causes (5).(Figure Presented) Conclusion(s): Administration of anti-CD19+ CAR-T is feasible in specialized community hospitals with outcomes similar to registrational clinical trials. Outpatient administration is feasible in selected patients, but subsequent hospitalization needs to be anticipated. CRS, neurotoxicity, cytopenias and infection remain challenges, while disease progression was the commonest cause of deathCopyright © 2023 American Society for Transplantation and Cellular Therapy

Prognosis Score for Overall Survival with CAR-T Therapy in Aggressive Lymphoma

Background: Despite the transformative potential of chimeric antigen receptor T (CAR-T) therapy, more tools to assist with identifying patients with increased likelihood of benefitting from this therapy will be helpful, particularly given the logistical complexity and socio-economic demands for CAR-T relative to other therapies. Health care resource restriction during the COVID-19 pandemic highlights the need for these tools. We present a simple survival score that uses 3 readily available clinical labs: platelet (plt), absolute lymphocyte count (ALC), and Lactate dehydrogenase (LDH), to predict the risk of dying within 6 months of CAR-T therapy in patients with aggressive lymphoma. Method(s): We conducted a retrospective chart review of patients with aggressive non-Hodgkin lymphoma (NHL) who received FDA-approved CAR-T between Jan 2018 to Jan 2022 at Mayo Clinic Rochester.(Table Presented)Results: Among a total of 110 pts who received CAR-T, 27 (25%) pts died within the first 6 months post CAR-T infusion (OS <= 6 months). Disease progression was the main cause of death (18/25, 72%), followed by infection (4/25, 16%), CAR-T related (HLH/MAS, 2/25, 8%), second primary malignancy (1/25, 4%) and unknown (2/25, 8%).Baseline demographics were comparable between the OS>6months and <=6months groups (Table 1). Patients' ECOG, Karnofsky performance status and 11 labs at the time of evaluation for CAR-T therapy (initial eligibility assessment, prior to leukapheresis) were compared between those who died from any cause within 6 months of CAR-T infusion and those who did not. Hemoglobin, plt, ALC, absolute monocyte count, CRP, ferritin, and LDH were selected as clinically and/or statistically significant variables for multivariate testing. Multivariate regression with boot-strap testing identified plt, ALC, and LDH as the most predictive variables with 80.9+/-11.7% accuracy for predicting death within 6 months of CAR-T infusion. Patients were scored 0-3 using these 3 labs, with 1 point assigned for plt <= 100 X109/L, ALC <= 0.4 X109/L, or LDH > 222 U/L (upper limit of normal). OS by this survival score is shown in Figure 1.(Figure Presented)Discussion: Due to the curative potential of CAR-T, patients with broader characteristics than those treated on registration studies have been treated in standard of care practice. While an estimated 5%-10% risk of CAR-T associated deaths in the first 3 months is seen across all patients in clinical trials, predictors for early death after CAR-T in real-world patient populations can provide additional context for pts and providers when selecting treatment. This survival score is important proof of concept that a simple model using readily accessible clinical labs at the time of CAR-T evaluation could provide additional context to help with additional clinical decision-making. Multicenter prospective studies will help define and validate the definitive survival scoring system.Copyright © 2023 American Society for Transplantation and Cellular Therapy

Infectious complications of chimeric antigen receptor (CAR) T-cell therapies.

CAR T-cells have revolutionized the treatment of many hematological malignancies. Thousands of patients with lymphoma, acute lymphoblastic leukemia, and multiple myeloma have received this "living medicine" and achieved durable remissions. Their place in therapy continues to evolve, and there is ongoing development of new generation CAR constructs, CAR T-cells against solid tumors and CAR T-cells against chronic infections like human immunodeficiency virus and hepatitis B. A significant fraction of CAR T-cell recipients, unfortunately, develop infections. This is in part due to factors intrinsic to the patient, but also to the treatment, which requires lymphodepletion (LD), causes neutropenia and hypogammaglobulinemia and necessarily increases the state of immunosuppression of the patient. The goal of this review is to present the infectious complications of CAR T-cell therapy, explain their temporal course and risk factors, and provide recommendations for their prevention, diagnosis, and management.

Design and characterization of chimeric Rabies-SARS-CoV-2 virus-like particles for vaccine purposes.

Due to the high number of doses required to achieve adequate coverage in the context of COVID-19 pandemics, there is a great need for novel vaccine developments. In this field, there have been research approaches that focused on the production of SARS-CoV-2 virus-like particles. These are promising vaccine candidates as their structure is similar to that of native virions but they lack the genome, constituting a biosafe alternative. In order to produce these structures using mammal cells, it has been established that all four structural proteins must be expressed. Here we report the generation and characterization of a novel chimeric virus-like particle (VLP) that can be produced by the expression of a single novel fusion protein that contains SARS-CoV-2 spike (S) ectodomain fused to rabies glycoprotein membrane anchoring region in HEK293 cells. This protein is structurally similar to native S and can autonomously bud forming enveloped VLPs that resemble native virions both in size and in morphology, displaying S ectodomain and receptor binding domain (RBD) on their surface. As a proof of concept, we analyzed the immunogenicity of this vaccine candidate in mice and confirmed the generation of anti-S, anti-RBD, and neutralizing antibodies. KEY POINTS: • A novel fusion rabies glycoprotein containing S ectodomain was designed. • Fusion protein formed cVLPs that were morphologically similar to SARS-CoV-2 virions. • cVLPs induced anti-S, anti-RBD, and neutralizing antibodies in mice.

Development and validity assessment of ELISA test with recombinant chimeric protein of SARS-CoV-2.

Serological tests developed for COVID-19 diagnostic are based on antibodies specific for SARS-CoV-2 antigens. Most of the antigens consist of a fragment or a whole amino acid sequence of the nucleocapsid or spike proteins. We evaluated a chimeric recombinant protein as an antigen in an ELISA test, using the most conserved and hydrophilic portions of the S1-subunit of the S and Nucleocapsid (N) proteins. These proteins, individually, indicated a suitable sensitivity of 93.6 and 100% and a specificity of 94.5 and 91.3%, respectively. However, our study with the chimera containing S1 and N proteins of SARS-CoV-2 suggested that the recombinant protein could better balance both the sensitivity (95.7%) and the specificity (95.5%) of the serological assay when comparing with the ELISA test using the antigens N and S1, individually. Accordingly, the chimera showed a high area under the ROC curve of 0.98 (CI 95% 0.958-1). Thus, our chimeric approach could be used to assess the natural exposure against SARS-CoV-2 virus over time, however, other tests will be necessary to better understand the behaviour of the chimera in samples from people with different vaccination doses and/or infected with different variants of the virus.

A covalent opsonization approach to enhance synthetic immunity against viral escape variants.

The sensitivity of therapeutic antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral "escape" mutations has inspired efforts to develop treatment strategies that are still effective in the face of rapidly mutating viral surface proteins. Here, we demonstrate a chemical strategy that enforces viral opsonization by natural serum antibodies. This strategy uses chimeric molecules that we call covalent viral opsonizers, which covalently label viral surface proteins, with synthetic antibody-binding ligands. As a proof of concept, we develop covalent viral opsonizers that covalently label the spike protein on SARS-CoV-2 using a "mutation-proof" small-molecule-binding ligand for anti-dinitrophenyl serum antibodies. In model assays, we observe that covalent viral opsonizers can rapidly and selectively covalently label the receptor-binding domain of both native and mutant spike proteins, leading to antibody opsonization. Opsonization mediated by this strategy is able to efficiently block the key binding domain interactions, in contrast to non-covalent analogs. We also show that covalent viral opsonizers enact targeted anti-viral phagocytotic immune function. This strategy has potential general utility for the rapid deployment of anti-viral synthetic immunotherapeutics at the onset of a new pandemic to reinforce vaccination and antibody engineering efforts.

Vaccines for the prevention of infections in adults with haematological malignancies

Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. To assess the benefits and adverse effects of vaccines for the prevention of infections in adults with haematological malignancies.Copyright © 2023 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

Epidemiology of Pemphigus.

Pemphigus is an epidemiologically heterogeneous group of autoimmune bullous diseases comprising pemphigus vulgaris (PV), pemphigus foliaceus, paraneoplastic pemphigus, IgA pemphigus, and pemphigus herpetiformis. Recently, our knowledge about the frequency of pemphigus, which is highly variable between different populations, has considerably expanded, and the first non-HLA genes associated with PV have been identified. In addition, a variety of comorbidities, including other autoimmune diseases, hematological malignancies, and psoriasis, have been described in this variant. Here, initial data about the impact of COVID-19 on this fragile patient population are discussed and perspectives for future epidemiological studies are outlined.