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Influenza viruses are an important cause of human morbidity and mortality. Influenza uses hemagglutinin, a trimeric surface protein whose monomers are composed of a head and a stalk domain, for immune evasion and cell entry. As the head domain is under constant antigenic drift, eliciting neutralizing antibodies through vaccination against its evolutionarily more conserved stalk domain is a key goal in the treatment of this infection. It is unknown how temperature affects the formation of hemagglutinin‐antibody complexes, particularly with respect to temperatures relevant for the human respiratory tract. Using molecular dynamics simulations and free energy calculations, we determined that bending of hemagglutinin's head domains, an initial step in the process of cell attachment, is present at hypothermia (36 °C), but not at higher temperatures. These conformational changes lead not only to exposure of new epitopes in its stalk domains, but also to enhanced binding of a neutralizing antibody. [ABSTRACT FROM AUTHOR]

Ovarian cancer is the second most common malignant neoplasm of gynecological origin and the leading cause of death from cancer in the female reproductive system worldwide. This scenario is largely due to late diagnoses, often in advanced stages, and the development of chemoresistance by cancer cells. These challenges highlight the need for alternative treatments, with immunotherapy being a promising option. Cancer immunotherapy involves triggering an anti-tumor immune response and developing immunological memory to eliminate malignant cells, prevent recurrence, and inhibit metastasis. Some ongoing research investigate potentially immunological advancements in the field of cancer vaccines, immune checkpoint blockade, CAR-T cell, and other strategies. [ABSTRACT FROM AUTHOR]

In B-cell malignancies, the overexpression of MYC is associated with poor prognosis, but its mechanism underlying resistance to immunochemotherapy remains less clear. In further investigations of this issue, we show here that the pharmacological inhibition of MYC in various lymphoma and multiple myeloma cell lines, as well as patient-derived primary tumor cells, enhances their susceptibility to NK cell-mediated cytotoxicity induced by conventional antibodies targeting CD20 (rituximab) and CD38 (daratumumab), as well as T cell-mediated cytotoxicity induced by the CD19-targeting bispecific T-cell engager blinatumomab. This was associated with upregulation of the target antigen only for rituximab, suggesting additional escape mechanisms. To investigate these mechanisms, we targeted the MYC gene in OCI-LY18 cells using CRISPR-Cas9 gene-editing technology. CRISPR-Cas9-mediated MYC targeting not only upregulated CD20 but also triggered broader apoptotic pathways, upregulating pro-apoptotic PUMA and downregulating anti-apoptotic proteins BCL-2, XIAP, survivin and MCL-1, thereby rendering tumor cells more prone to apoptosis, a key tumor-lysis mechanism employed by T-cells and NK-cells. Moreover, MYC downregulation boosted T-cell activation and cytokine release in response to blinatumomab, revealing a MYC-mediated T-cell suppression mechanism. In conclusion, MYC overexpressing tumor cells mitigated the efficacy of therapeutic antibodies through several non-overlapping mechanisms. Given the challenges associated with direct MYC inhibition due to toxicity, successful modulation of MYC-mediated immune evasion mechanisms may improve the outcome of immunotherapeutic approaches in B-cell malignancies. [ABSTRACT FROM AUTHOR]

CD99, a type I transmembrane protein, emerges as a promising therapeutic target due to its heightened expression in T cell acute lymphoblastic leukemia (T-ALL). This characteristic renders it a potential marker for minimal residual disease detection and an appealing target for antibody-based treatments. Previous studies have revealed that a mouse monoclonal antibody, mAb MT99/3, selectively binds to CD99, triggering apoptosis in T-ALL/T-LBL cells while preserving the integrity of healthy cells. By targeting CD99, mAb MT99/3 suppresses antigen presentation and disrupts T cell functions, offering promise for addressing hyperresponsive T cell conditions. To facilitate clinical translation, we developed a humanized ScFv variant of mAb MT99/3, termed HuScFvMT99/3 in "ScFvkh" design. Structural analysis confirms its resemblance to the original antibody, and the immunoreactivity of HuScFvMT99/3 against CD99 is preserved. The fully humanized version of antibody HuMT99/3 was further engineered, exhibiting similar binding affinity at the 10−10 M level and specificity to the CD99 epitope without antigenic shift. HuMT99/3 demonstrates remarkable selectivity, recognizing both malignant and normal T cells but inducing apoptosis only in T-ALL/T-LBL cells, highlighting its potential for safe and targeted therapy. [ABSTRACT FROM AUTHOR]

Pancreatic cancer remains one of the deadliest malignancies, with a consistently low five-year survival rate for the past several decades. This is in stark contrast to other cancers, which have seen significant improvement in survival and prognosis due to recent developments in therapeutic modalities. These modest improvements in pancreatic cancer outcomes have primarily resulted from minor advances in cytotoxic chemotherapeutics, with limited progress in other treatment approaches. A major focus of current therapeutic research is the further development of immunomodulatory therapies characterized by antibody-based approaches, cellular therapies, and vaccines. Although initial results utilizing immunotherapy in pancreatic cancer have been mixed, recent clinical trials have demonstrated significant improvements in patient outcomes. In this review, we detail these three approaches to immunomodulation, highlighting their common targets and distinct shortcomings, and we provide a narrative summary of completed and ongoing clinical trials that utilize these approaches to immunomodulation. Within this context, we aim to inform future research efforts by identifying promising areas that warrant further exploration. [ABSTRACT FROM AUTHOR]

Abstract The incidence of multiple myeloma (MM) has surged globally, particularly in Latin American countries, and is attributable to an aging population and increased life expectancy. This systematic review analyzes the epidemiology, patient characteristics, and treatment outcomes for MM in selected Latin American countries: Brazil, Mexico, Colombia, Argentina, Chile, Peru, and Uruguay. PubMed and the Latin American and Caribbean Health Sciences Literature (LILACS), conference abstracts (between June 2019 and June 2022), and GLOBOCAN registry (January 2010 to June 2022) were electronically searched. Qualitative analysis employed the Joanna Briggs Institute's critical appraisal tool. Among the 586 screened articles, 26 met the inclusion criteria. The participants’ median age ranged from 54 to 67 years. GLOBOCAN data revealed that for MM, Brazil and Uruguay had the highest and lowest incidence, 5‐year prevalence, and mortality, respectively. Immunoglobulin G was the most common subtype detected. Stage III was frequently diagnosed. Though many approved drugs are available and bispecific antibodies hold promise as a future therapy, limited access, especially for CAR‐T cell‐based therapy remains a concern. The incidence of MM is increasing in Latin America. Resource constraints and costs hinder access to novel drugs and regimens. Understanding disease patterns and patient characteristics is vital to improve MM management in these countries.

Summary There is accumulating evidence of BCMA and GPRC5D loss after treatment with T‐cell redirecting therapies in patients with relapsed/refractory multiple myeloma (RRMM). While complete CD38 loss is not observed upon relapses after treatment with anti‐CD38 monoclonal antibodies (mAb), there is downregulation of surface CD38 expression and decreased number and function of NK cells, which renders these patients resistant to retreatment with anti‐CD38 mAb. Here, we provide preclinical evidence that RRMM patients previously exposed to anti‐CD38 mAb could benefit from T‐cell‐based immunotherapy that depend less on CD38 antigen density and NK‐cell activity, such as the novel CD38/CD3xCD28 trispecific T‐cell engager, SAR442257. [ABSTRACT FROM AUTHOR]

Summary Since the approval of the CD20‐targeting monoclonal antibody (mAb) rituximab for the treatment of lymphoma in 1997, mAb therapy has significantly transformed cancer treatment. With over 90 FDA‐approved mAbs for the treatment of various hematological and solid cancers, modern cancer treatment relies heavily on these therapies. The overwhelming success of mAbs as cancer therapeutics is attributed to their broad applicability, high safety profile, and precise targeting of cancer‐associated surface antigens. Furthermore, mAbs can induce various anti‐tumor cytotoxic effector mechanisms including antibody‐dependent cellular cytotoxicity (ADCC), antibody‐dependent cellular phagocytosis (ADCP), and complement‐dependent cytotoxicity (CDC), all of which are mediated via their fragment crystallizable (Fc) domain. Over the past decades, these effector mechanisms have been substantially improved through Fc domain engineering. In this review, we will outline the different approaches to enhance Fc effector functions via Fc engineering of mAbs, with a specific emphasis on the so‐called “HexaBody” technology, which is designed to enhance the hexamerization of mAbs on the target cell surface, thereby inducing greater complement activation, CDC, and receptor clustering. The review will summarize the development, preclinical, and clinical testing of several HexaBodies designed for the treatment of B‐cell malignancies, as well as the potential use of the HexaBody technology beyond Fc‐mediated effector functions. [ABSTRACT FROM AUTHOR]

The disease of transthyretin (TTR) amyloidosis (ATTR) has been known since the 1960s, and during the past 60 or so years, there has been a sustained period of steady discoveries that have led to the current model of ATTR pathogenesis. More recent research has achieved major advances in both diagnostics and therapeutics for ATTR, which are having a significant impact on ATTR patients today. Aiding these recent achievements has been the remarkable ability of cryo-electron microscopy (EM) to determine high-resolution structures of amyloid fibrils obtained from individual patients. Here, we will examine the cryo-EM structures of transthyretin amyloid fibrils to explore the structural basis of the two monoclonal antibody therapies for ATTR that are in clinical trials, ALXN-2220 and Coramitug, as well as to point out potential applications of this approach to other systemic amyloid diseases. [ABSTRACT FROM AUTHOR]

Aims Pulmonary vascular and right ventricular (RV) remodelling processes are important for development and progression of pulmonary hypertension (PH). The current study analysed the functional role of the extra domain A-containing fibronectin (ED-A+ Fn) for the development of PH by comparing ED-A+ Fn knockout (KO) and wild-type (WT) mice as well as the effects of an antibody-based therapeutic approach in a model of monocrotaline (MCT)-induced PH, which will be validated in a model of Sugen 5416/hypoxia-induced PH. Methods and results PH was induced using MCT (PH mice). Sixty-nine mice were divided into the following groups: sham-treated controls (WT: n = 7; KO: n = 7), PH mice without specific treatment (WT: n = 12; KO: n = 10), PH mice treated with a dual endothelin receptor antagonist (macitentan; WT: n = 6; KO: n = 11), WT PH mice treated with the F8 antibody, specifically recognizing ED-A+ Fn, (n = 8), and WT PH mice treated with an antibody of irrelevant antigen specificity (KSF, n = 8). Compared to controls, WT_PH mice showed a significant elevation of the RV systolic pressure (P = 0.04) and RV functional impairment including increased basal RV (P = 0.016) diameter or tricuspid annular plane systolic excursion (P = 0.008). In contrast, KO PH did not show such effects compared to controls (P = n.s.). In WT_PH mice treated with F8, haemodynamic and echocardiographic parameters were significantly improved compared to untreated WT_PH mice or those treated with the KSF antibody (P < 0.05). On the microscopic level, KO_PH mice showed significantly less tissue damage compared to the WT_PH mice (P = 0.008). Furthermore, lung tissue damage could significantly be reduced after F8 treatment (P = 0.04). Additionally, these findings could be verified in the Sugen 5416/hypoxia mouse model, in which F8 significantly improved echocardiographic, haemodynamic, and histologic parameters. Conclusion ED-A+ Fn is of crucial importance for PH pathogenesis representing a promising therapeutic target in PH. We here show a novel therapeutic approach using antibody-mediated functional blockade of ED-A+ Fn capable of attenuating and partially reversing PH-associated tissue remodelling. [ABSTRACT FROM AUTHOR]

The potency of antibody neutralization in cell culture has been used as the key criterion for selection of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for clinical development. As other aspects may also influence the degree of protection in vivo, we compared the efficacy of two neutralizing monoclonal antibodies (TRES6 and 4C12) targeting different epitopes of the receptor binding domain (RBD) of SARS-CoV-2 in a prophylactic setting in rhesus monkeys. All four animals treated with TRES6 had reduced viral loads in the upper respiratory tract 2 days after naso-oropharyngeal challenge with the Alpha SARS-CoV-2 variant. Starting 2 days after challenge, mutations conferring resistance to TRES6 were dominant in two of the rhesus monkeys, with both animals failing to maintain reduced viral loads. Consistent with its lower serum neutralization titer at the day of challenge, prophylaxis with 4C12 tended to suppress viral load at day 2 less efficiently than TRES6. However, a week after challenge, mean viral loads in the lower respiratory tract in 4C12-treated animals were lower than in the TRES6 group and no mutations conferring resistance to 4C12 could be detected in viral isolates from nasal or throat swabs. Thus, genetic barrier to resistance seems to be a critical parameter for the efficacy of prophylaxis with monoclonal antibodies against SARS-CoV-2. Furthermore, comparison of antibody concentrations in respiratory secretions to those in serum shows reduced distribution of the 4C12 antibody into respiratory secretions and a delay in the appearance of antibodies in bronchoalveolar lavage fluid compared to their appearance in secretions of the upper respiratory tract. IMPORTANCE Monoclonal antibodies are a powerful tool for the prophylaxis and treatment of acute viral infections. Hence, they were one of the first therapeutic agents licensed for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Oftentimes, the main criterion for the selection of antibodies for clinical development is their potency of neutralization in cell culture. By comparing two antibodies targeting the Spike protein of SARS-CoV-2, we now observed that the antibody that neutralized SARS-CoV-2 more efficiently in cell culture suppressed viral load in challenged rhesus monkeys to a lesser extent. Extraordinary rapid emergence of mutants of the challenge virus, which had lost their sensitivity to the antibody, was identified as the major reason for the reduced efficacy of the antibody in rhesus monkeys. Therefore, the viral genetic barrier to resistance to antibodies also affects their efficacy. [ABSTRACT FROM AUTHOR]

ABSTRACTThe development of specific, safe, and potent monoclonal antibodies (Abs) has led to novel therapeutic options for infectious disease. In addition to preventing viral infection through neutralization, Abs can clear infected cells and induce immunomodulatory functions through engagement of their crystallizable fragment (Fc) with complement proteins and Fc receptors on immune cells. Little is known about the role of Fc effector functions of neutralizing Abs in the context of encephalitic alphavirus infection. To determine the role of Fc effector function in therapeutic efficacy against Venezuelan equine encephalitis virus (VEEV), we compared the potently neutralizing anti-VEEV human IgG F5 (hF5) Ab with intact Fc function (hF5-WT) or containing the loss of function Fc mutations L234A and L235A (hF5-LALA) in the context of VEEV infection. We observed significantly reduced binding to complement and Fc receptors, as well as differential in vitro kinetics of Fc-mediated cytotoxicity for hF5-LALA compared to hF5-WT. The in vivo efficacy of hF5-LALA was comparable to hF5-WT at −24 and + 24 h post infection, with both Abs providing high levels of protection. However, when hF5-WT and hF5-LALA were administered + 48 h post infection, there was a significant decrease in the therapeutic efficacy of hF5-LALA. Together these results demonstrate that optimal therapeutic Ab treatment of VEEV, and possibly other encephalitic alphaviruses, requires neutralization paired with engagement of immune effectors via the Fc region.

Ovarian cancer is the second most common malignant neoplasm of gynecological origin and the leading cause of death from cancer in the female reproductive system worldwide. This scenario is largely due to late diagnoses, often in advanced stages, and the development of chemoresistance by cancer cells. These challenges highlight the need for alternative treatments, with immunotherapy being a promising option. Cancer immunotherapy involves triggering an anti-tumor immune response and developing immunological memory to eliminate malignant cells, prevent recurrence, and inhibit metastasis. Some ongoing research investigate potentially immunological advancements in the field of cancer vaccines, immune checkpoint blockade, CAR-T cell, and other strategies.

Transferrin receptor 1 (TfR1), also known as CD71, is a transmembrane protein involved in the cellular uptake of iron and the regulation of cell growth. This receptor is expressed at low levels on a variety of normal cells, but is upregulated on cells with a high rate of proliferation, including malignant cells and activated immune cells. Infection with the human immunodeficiency virus (HIV) leads to the chronic activation of B cells, resulting in high expression of TfR1, B-cell dysfunction, and ultimately the development of acquired immunodeficiency syndrome-related B-cell non-Hodgkin lymphoma (AIDS-NHL). Importantly, TfR1 expression is correlated with the stage and prognosis of NHL. Thus, it is a meaningful target for antibody-based NHL therapy. We previously developed a mouse/human chimeric IgG3 specific for TfR1 (ch128.1/IgG3) and showed that this antibody exhibits antitumor activity in an in vivo model of AIDS-NHL using NOD-SCID mice challenged intraperitoneally with 2F7 human Burkitt lymphoma (BL) cells that harbor the Epstein-Barr virus (EBV). We have also developed an IgG1 version of ch128.1 that shows significant antitumor activity in SCID-Beige mouse models of disseminated multiple myeloma, another B-cell malignancy. Here, we aim to explore the utility of ch128.1/IgG1 and its humanized version (hu128.1) in mouse models of AIDS-NHL. To accomplish this goal, we used the 2F7 cell line variant 2F7-BR44, which is more aggressive than the parental cell line and forms metastases in the brain of mice after systemic (intravenous) administration. We also used the human BL cell line JB, which in contrast to 2F7, is EBV-negative, allowing us to study both EBV-infected and non-infected NHL tumors. Treatment with ch128.1/IgG1 or hu128.1 of SCID-Beige mice challenged locally (subcutaneously) with 2F7-BR44 or JB cells results in significant antitumor activity against different stages of disease. Treatment of mice challenged systemically (intravenously) with either 2F7-BR44 or JB cells also showed significant antitumor activity, including long-term survival. Taken together, our results suggest that targeting TfR1 with antibodies, such as ch128.1/IgG1 or hu128.1, has potential as an effective therapy for AIDS-NHL.

Summary: The bendamustine–rituximab (BR) schedule is an efficient first‐line therapy in Waldenström macroglobulinaemia (WM). A previous analysis of 69 patients who received this treatment confirmed a high response rate and good progression‐free (PFS) and overall survival (OS). With a median follow‐up of 76.1 months (95% confidence interval [CI] 69.9–80.6), 5‐year outcome is still excellent at 66.63% (95% CI 56.09–79.17) for PFS and 80.01% (95% CI 70.82–90.41) for OS. The rate of secondary cancers is 17.66% (IQR 7.99–27.64) at 66 months. Relapsed patients who received ibrutinib as second‐line clearly benefited from this schedule. This confirms current recommendations suggesting BR long‐term efficacy as first‐line option in WM. [ABSTRACT FROM AUTHOR]

Summary: Due in part to racial disparities and underrepresentation in clinical studies, optimal therapies for Black patients with multiple myeloma remain undefined. This final analysis of GRIFFIN by race showed that the addition of daratumumab (D) to lenalidomide/bortezomib/dexamethasone (RVd) provides clinical benefit among both Black and White transplant‐eligible newly diagnosed patients compared with RVd alone. However, Black patients were more likely to discontinue ≥1 drug due to treatment‐emergent adverse events. In summary, these findings suggest a benefit of D‐RVd front‐line therapy among Black and White patients and underscore the importance of equitable treatment access for all patients. [ABSTRACT FROM AUTHOR]

Introduction: Convalescent plasma (CP) emerged as potential treatment for COVID-19 early in the pandemic. While efficacy in hospitalised patients has been lacklustre, CP may be beneficial at the first stages of disease. Despite multiple new variants emerging, no trials have involved analyses on variant-specific antibody titres of CP. Methods: We recruited hospitalised COVID-19 patients within 10 days of symptom onset and, employing a double-blinded approach, randomised them to receive 200 ml convalescent plasma with high (HCP) or low (LCP) neutralising antibody (NAb) titre against the ancestral strain (Wuhan-like variant) or placebo in 1:1:1 ratio. Primary endpoints comprised intubation, corticosteroids for symptom aggravation, and safety assessed as serious adverse events. For a pre-planned ad hoc analysis, the patients were regrouped by infused CP’s NAb titers to variants infecting the recipients i.e. by titres of homologous HCP (hHCP) or LCP (hLCP). Results: Of the 57 patients, 18 received HCP, 19 LCP and 20 placebo, all groups smaller than planned. No significant differences were found for primary endpoints. In ad hoc analysis, hHCPrecipients needed significantly less respiratory support, and appeared to be given corticosteroids less frequently (1/14; 7.1%) than those receiving hLCP (9/23; 39.1%) or placebo (8/20; 40%), (p = 0.077). Discussion: Our double-blinded, placebo-controlled CP therapy trial remained underpowered and does not allow any firm conclusions for early-stage hospitalised COVID-19 patients. Interestingly, however, regrouping by homologous – recipients’ variant-specific – CP titres suggested benefits for hHCP. We encourage similar re-analysis of ongoing/previous larger CP studies. [ABSTRACT FROM AUTHOR]

CD99 was demonstrated to be a potential target for antibody therapy on T-acute lymphoblastic leukemia (T-ALL). The ligation of CD99 by certain monoclonal antibodies (mAbs) induced T-ALL apoptosis. However, the molecular basis contributing to the apoptosis of T-ALL upon anti-CD99 mAb engagement remains elusive. In this study, using our generated anti-CD99 mAb clone MT99/3 (mAb MT99/3), mAb MT99/3 engagement strongly induced apoptosis of T-ALL cell lines, but not in non-malignant peripheral blood cells. By transcriptome analysis, upon mAb MT99/3 ligation, 13 apoptosis-related genes, including FOS, TNF, FASLG, BCL2A1, JUNB, SOCS1, IL27RA, PTPN6, PDGFA, NR4A1, SGK1, LPAR5 and LTB, were significantly upregulated. The epitope of CD99 recognized by mAb MT99/3 was then identified as the VDGENDDPRPP at residues 60–70 of CD99, which has never been reported. To the best of our knowledge, this is the first transcriptome data conducted in T-ALL with anti-CD99 mAb engagement. These findings provide new insights into CD99 implicated in the apoptosis of T-ALL. The identification of a new epitope and apoptosis-related genes that relate to the induction of apoptosis by mAb MT99/3 may serve as a new therapeutic target for T-ALL. The anti-CD99 mAb clone MT99/3 might be a candidate for further development of a therapeutic antibody for T-ALL therapy. [ABSTRACT FROM AUTHOR]

Alternative splicing (AS) is an important molecular biological mechanism regulated by complex mechanisms involving a plethora of cis and trans-acting elements. Furthermore, AS is tissue specific and altered in various pathologies, including infectious, inflammatory, and neoplastic diseases. Recently developed immuno-oncological therapies include monoclonal antibodies (mAbs) and chimeric antigen receptor (CAR) T cells targeting, among others, immune checkpoint (ICP) molecules. Despite therapeutic successes have been demonstrated, only a limited number of patients showed long-term benefit from these therapies with tumor entity-related differential response rates were observed. Interestingly, splice variants of common immunotherapeutic targets generated by AS are able to completely escape and/or reduce the efficacy of mAb- and/or CAR-based tumor immunotherapies. Therefore, the analyses of splicing patterns of targeted molecules in tumor specimens prior to therapy might help correct stratification, thereby increasing therapy success by antibody panel selection and antibody dosages. In addition, the expression of certain splicing factors has been linked with the patients' outcome, thereby highlighting their putative prognostic potential. Outstanding questions are addressed to translate the findings into clinical application. This review article provides an overview of the role of AS in (tumor) diseases, its molecular mechanisms, clinical relevance, and therapy response. [ABSTRACT FROM AUTHOR]

Summary: Systemic light chain (AL) amyloidosis is a relapsing plasma cell disorder. Therapy is limited, particularly for triple‐class refractory disease. We report the use of belantamab mafodotin, a BCMA‐directed drug–antibody conjugate, for relapsed AL amyloidosis, including patients traditionally excluded from clinical trials. Thirty‐one patients were reviewed, with a median of three prior lines of therapy. The median follow‐up was 12 months (95% CI 4–19), and a median of five doses were delivered. The best haematological overall response rate was 71%, and the complete/very good partial response was 58%. Sixty‐eight percent had keratopathy and improved in all. Belantamab mafodotin has high efficacy and good tolerability in patients with relapsed AL amyloidosis. [ABSTRACT FROM AUTHOR]

Amubarvimab-romlusevimab is a commonly recommended antiviral treatment in China for adult patients with mild or moderate SARS-CoV-2 infections, especially for patients with a high risk factor for progression to severe COVID-19. However, its exact efficacy in patients with severe Covid-19 is not yet known.This is a single-center retrospective cohort study, in which we collected the general data, laboratory tests, radiological characteristics, viral conversion status, and prognosis of the disease from patients with COVID-19 hospitalized, from December 2022 to March 2023 in the Department of Critical Care Medicine. The amubarvimab-romlusevimab therapy can reduce the 28-day mortality (29.79 % vs 51.35 %, p = 0.02), and ICU mortality (29.79 % vs 55.41 %, p = 0.006) of severe COVID-19.A 1:1 PSM (Propensity Score Matching) was performed to reduce bias, in order to ensure the two groups were balanced and comparable. In the matched population (n = 47), there were no statistically significant differences between the mAbs (monoclonal antibody)group and the Non-antiviral group in 28-day, and thromboembolic events in COVID-19 patients. The 40-day survival analysis shows that mAbs therapy can improve patient prognosis (HR = 0.45, 95%CI = 0.26–0.76, p = 0.008). However, no significant intergroup difference in the 40-day cumulative viral conversion rate. In a univariate Cox regression analysis, The Amubarvimab - romlusevimab therapy(HR:0.464; CI:[0.252–0.853]; p:0.013) is a protective factor and CRP, PCT, PLT, Lactate, PT, PT-INR, and pt% level at admission were risk factors for clinical prognosis. After including the above covariates, Multifactorial COX regression shows that the Amubarvimab - romlusevimab therapy(HR:0.392; CI:[0.211–0.729]; p:0.003), CRP, Lactate and PT-INR at admission are independent factors for mortality of severe COVID-19. Based on the current data, we conclude that amubarvimab-romlusevimab therapy is beneficial for patients with severe COVID-19.

CD99, a type I transmembrane protein, emerges as a promising therapeutic target due to its heightened expression in T cell acute lymphoblastic leukemia (T-ALL). This characteristic renders it a potential marker for minimal residual disease detection and an appealing target for antibody-based treatments. Previous studies have revealed that a mouse monoclonal antibody, mAb MT99/3, selectively binds to CD99, triggering apoptosis in T-ALL/T-LBL cells while preserving the integrity of healthy cells. By targeting CD99, mAb MT99/3 suppresses antigen presentation and disrupts T cell functions, offering promise for addressing hyperresponsive T cell conditions. To facilitate clinical translation, we developed a humanized ScFv variant of mAb MT99/3, termed HuScFvMT99/3 in “ScFvkh” design. Structural analysis confirms its resemblance to the original antibody, and the immunoreactivity of HuScFvMT99/3 against CD99 is preserved. The fully humanized version of antibody HuMT99/3 was further engineered, exhibiting similar binding affinity at the 10−10 M level and specificity to the CD99 epitope without antigenic shift. HuMT99/3 demonstrates remarkable selectivity, recognizing both malignant and normal T cells but inducing apoptosis only in T-ALL/T-LBL cells, highlighting its potential for safe and targeted therapy.

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Lipolysis‐stimulated lipoprotein receptor (LSR) is known as a lipoprotein receptor. LSR is expressed in various solid tumors, including epithelial ovarian, gastric, and colon cancers. High LSR expression is significantly associated with poor prognosis, but its role in cancer has not been fully elucidated. LSR belongs to the Ig protein superfamily, which is conserved in B7 family. Here, we assessed LSR as a novel immune checkpoint molecule. We developed a novel anti‐LSR antibody (#27‐6 mF‐18) that defects antibody‐dependent cellular cytotoxicity and complement‐dependent cytotoxicity activity. The #27‐6 mF‐18 cross‐reacts with both human and mouse LSR. We found that LSR was expressed on 4T1 murine breast cancer cell line. The #27‐6 mF‐18 exhibited antitumor effects against the 4T1 syngeneic tumor model, a poor immunogenic model refractory to treatment with anti‐PD‐1 or anti‐CTLA‐4 antibodies. Compared with control antibody‐treated mice, mice treated with #27‐6 mF‐18 showed significantly increased numbers of CD8+ T cells and a ratio of activated CD8+ T cells infiltrated in the tumor tissue. This antitumor effect was abrogated by CD8+ T‐cell depletion through anti‐CD8 antibody treatment, indicating that LSR negatively regulates tumor immunity by repressing CD8+ T cells. These findings show that LSR negatively regulates T‐cell immune activity. LSR targeting could provide immune checkpoint inhibitors for cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Non-small cell lung cancer (NSCLC), a major life-threatening disease accounting for 85% of all lung cancer cases, has been treated with tyrosine kinase inhibitors (TKIs), but often resulted in drug resistance, and approximately 60% of TKI-resistant cases are due to acquired secondary (epithelial growth factor receptor) EGFR-T790M mutation. To identify alternative targets for TKI-resistant NSCLC with EGFR-T790M mutation, we found that the three globo-series glycosphingolipids are increasingly expressed on this type of NSCLC cell lines, and among them, the increase of stage-specific embryonic antigen-4 (SSEA-4) expression is the most significant. Compared to TKI-sensitive cell lines, SSEA-4 and the key enzyme ß3GalT5 responsible for the synthesis of SSEA3 are more expressed in TKI-resistant NSCLC cell lines with EGFR-T790M mutation, and the expression levels strongly correlate with poor survival in patients with EGFR mutation. In addition, we demonstrated that a SSEA-4 targeted monoclonal antibody, especially the homogeneous glycoform with well-defined Fc glycan designed to improve effective functions, is highly effective against this subpopulation of NSCLC in cell-based and animal studies. These findings provide a direction for the prediction of tumor recurrence and treatment of TKI-resistant NSCLC with EGFR-T790M mutation. [ABSTRACT FROM AUTHOR]

The emergence of Omicron lineages and descendent subvariants continues to present a severe threat to the effectiveness of vaccines and therapeutic antibodies. We have previously suggested that an insufficient mucosal immunoglobulin A (IgA) response induced by the mRNA vaccines is associated with a surge in breakthrough infections. Here, we further show that the intramuscular mRNA and/or inactivated vaccines cannot sufficiently boost the mucosal secretory IgA response in uninfected individuals, particularly against the Omicron variant. We thus engineered and characterized recombinant monomeric, dimeric, and secretory IgA1 antibodies derived from four neutralizing IgG monoclonal antibodies (mAbs 01A05, rmAb23, DXP-604, and XG014) targeting the receptor-binding domain of the spike protein. Compared to their parental IgG antibodies, dimeric and secretory IgA1 antibodies showed a higher neutralizing activity against different variants of concern (VOCs), in part due to an increased avidity. Importantly, the dimeric or secretory IgA1 form of the DXP-604 antibody significantly outperformed its parental IgG antibody, and neutralized the Omicron lineages BA.1, BA.2, and BA.4/5 with a 25-to 75-fold increase in potency. In human angiotensin converting enzyme 2 (ACE2) transgenic mice, a single intranasal dose of the dimeric IgA DXP-604 conferred prophylactic and therapeutic protection against Omicron BA.5. Thus, dimeric or secretory IgA delivered by nasal administration may potentially be exploited for the treatment and prevention of Omicron infection, thereby providing an alternative tool for combating immune evasion by the current circulating subvariants and, potentially, future VOCs. [ABSTRACT FROM AUTHOR]

Long QT syndrome (LQTS) type 3 although less common than the first two forms, differs in that arrhythmic events are less likely triggered by adrenergic stimuli and are more often lethal. Effective pharmacological treatment is challenged by interindividual differences, mutation dependence, and adverse effects, translating into an increased use of invasive measures (implantable cardioverter-defibrillator, sympathetic denervation) in patients with LQTS type 3. Previous studies have demonstrated the therapeutic potential of polyclonal KCNQ1 antibody for LQTS type 2. Here, we sought to identify a monoclonal KCNQ1 antibody that preserves the electrophysiological properties of the polyclonal form. Using hybridoma technology, murine monoclonal antibodies were generated, and patch clamp studies were performed for functional characterization. We identified a monoclonal KCNQ1 antibody able to normalize cardiac action potential duration and to suppress arrhythmias in a pharmacological model of LQTS type 3 using human-induced pluripotent stem cell-derived cardiomyocytes. [ABSTRACT FROM AUTHOR]

ABSTRACTAlthough severe coronavirus disease 2019 (COVID-19) and hospitalization associated with COVID-19 are generally preventable among healthy vaccine recipients, patients with immunosuppression have poor immunogenic responses to COVID-19 vaccines and remain at high risk of infection with SARS-CoV-2 and hospitalization. In addition, monoclonal antibody therapy is limited by the emergence of novel SARS-CoV-2 variants that have serially escaped neutralization. In this context, there is interest in understanding the clinical benefit associated with COVID-19 convalescent plasma collected from persons who have been both naturally infected with SARS-CoV-2 and vaccinated against SARS-CoV-2 (“vax-plasma”). Thus, we report the clinical outcome of 386 immunocompromised outpatients who were diagnosed with COVID-19 and who received contemporary COVID-19-specific therapeutics (standard-of-care group) and a subgroup who also received concomitant treatment with very high titer COVID-19 convalescent plasma (vax-plasma group) with a specific focus on hospitalization rates. The overall hospitalization rate was 2.2% (5 of 225 patients) in the vax-plasma group and 6.2% (10 of 161 patients) in the standard-of-care group, which corresponded to a relative risk reduction of 65% (P = 0.046). Evidence of efficacy in nonvaccinated patients cannot be inferred from these data because 94% (361 of 386 patients) of patients were vaccinated. In vaccinated patients with immunosuppression and COVID-19, the addition of vax-plasma or very high titer COVID-19 convalescent plasma to COVID-19-specific therapies reduced the risk of disease progression leading to hospitalization.IMPORTANCEAs SARS-CoV-2 evolves, new variants of concern (VOCs) have emerged that evade available anti-spike monoclonal antibodies, particularly among immunosuppressed patients. However, high-titer COVID-19 convalescent plasma continues to be effective against VOCs because of its broad-spectrum immunomodulatory properties. Thus, we report clinical outcomes of 386 immunocompromised outpatients who were treated with COVID-19-specific therapeutics and a subgroup also treated with vaccine-boosted convalescent plasma. We found that the administration of vaccine-boosted convalescent plasma was associated with a significantly decreased incidence of hospitalization among immunocompromised COVID-19 outpatients. Our data add to the contemporary data providing evidence to support the clinical utility of high-titer convalescent plasma as antibody replacement therapy in immunocompromised patients.

The disease of transthyretin (TTR) amyloidosis (ATTR) has been known since the 1960s, and during the past 60 or so years, there has been a sustained period of steady discoveries that have led to the current model of ATTR pathogenesis. More recent research has achieved major advances in both diagnostics and therapeutics for ATTR, which are having a significant impact on ATTR patients today. Aiding these recent achievements has been the remarkable ability of cryo-electron microscopy (EM) to determine high-resolution structures of amyloid fibrils obtained from individual patients. Here, we will examine the cryo-EM structures of transthyretin amyloid fibrils to explore the structural basis of the two monoclonal antibody therapies for ATTR that are in clinical trials, ALXN-2220 and Coramitug, as well as to point out potential applications of this approach to other systemic amyloid diseases.

Since the successful introduction of checkpoint inhibitors targeting the adaptive immune system, monoclonal antibodies inhibiting CD47-SIRPα interaction have shown promise in enhancing anti-tumor treatment efficacy. Apart from SIRPα, neutrophils express a broad repertoire of inhibitory receptors, including several members of the sialic acid-binding receptor (SIGLEC) family. Here, we demonstrate that interaction between tumor cell-expressed sialic acids and SIGLEC-5/14 on neutrophils inhibits antibody-dependent cellular cytotoxicity (ADCC). We observed that conjugate formation and trogocytosis, both essential processes for neutrophil ADCC, were limited by the sialic acid-SIGLEC-5/14 interaction. During neutrophil-tumor cell conjugate formation, we found that inhibition of the interaction between tumor-expressed sialic acids and SIGLEC-5/14 on neutrophils increased the CD11b/CD18 high affinity conformation. By dynamic acoustic force measurement, the binding between tumor cells and neutrophils was assessed. The interaction between SIGLEC-5/14 and the sialic acids was shown to inhibit the CD11b/CD18-regulated binding between neutrophils and antibody-opsonized tumor cells. Moreover, the interaction between sialic acids and SIGLEC-5/14-consequently hindered trogocytosis and tumor cell killing. In summary, our results provide evidence that the sialic acid-SIGLEC-5/14 interaction is an additional target for innate checkpoint blockade in the tumor microenvironment. [ABSTRACT FROM AUTHOR]

Chronic lymphocytic leukemia (CLL) is a disease characterized by the accumulation of mature CD19+CD5+CD23+ B cells in the bloodstream and in lymphoid organs. It usually affects people over 70 years of age, which limits the options for treatments. The disease is typically well-managed, but to date is still incurable. Hence, the need for novel therapeutic strategies remains. Nurse-like cells (NLCs) are major components of the microenvironment for CLL, supporting tumor cell survival, proliferation, and even drug resistance. They are of myeloid lineage, guided toward differentiating into their tumor-supportive role by the CLL cells themselves. As such, they are analogous to tumor-associated macrophages and represent a major therapeutic target. Previously, it was found that a mushroom extract, Active Hexose-Correlated Compound (AHCC), promoted the death of acute myeloid leukemia cells while preserving normal monocytes. Given these findings, it was asked whether AHCC might have a similar effect on the abnormally differentiated myeloid-lineage NLCs in CLL. CLL-patient PBMCs were treated with AHCC, and it was found that AHCC treatment showed a direct toxic effect against isolated CLL cells. In addition, it significantly reduced the number of tumor-supportive NLCs and altered their phenotype. The effects of AHCC were then tested in the Eµ-TCL1 mouse model of CLL and the MllPTD/WT Flt3ITD/WT model of AML. Results showed that AHCC not only reduced tumor load and increased survival in the CLL and AML models, but it also enhanced antitumor antibody treatment in the CLL model. These results suggest that AHCC has direct and indirect effects against CLL and that it may be of benefit when combined with existing treatments. [ABSTRACT FROM AUTHOR]

The activating receptor natural killer group 2, member D (NKG2D) represents an attractive target for immunotherapy as it exerts a crucial role in cancer immunosurveillance by regulating the activity of cytotoxic lymphocytes. In this study, a panel of novel NKG2D-specific single-chain fragments variable (scFv) were isolated from naïve human antibody gene libraries and fused to the fragment antigen binding (Fab) of rituximab to obtain [CD20×NKG2D] bibodies with the aim to recruit cytotoxic lymphocytes to lymphoma cells. All bispecific antibodies bound both antigens simultaneously. Two bibody constructs, [CD20×NKG2D#3] and [CD20×NKG2D#32], efficiently activated natural killer (NK) cells in co-cultures with CD20+ lymphoma cells. Both bibodies triggered NK cell-mediated lysis of lymphoma cells and especially enhanced antibodydependent cell-mediated cytotoxicity (ADCC) by CD38 or CD19 specific monoclonal antibodies suggesting a synergistic effect between NKG2D and FcgRIIIA signaling pathways in NK cell activation. The [CD20×NKG2D] bibodies were not effective in redirecting CD8+ T cells as single agents, but enhanced cytotoxicity when combined with a bispecific [CD19×CD3] T cell engager, indicating that NKG2D signaling also supports CD3-mediated T cell activation. In conclusion, engagement of NKG2D with bispecific antibodies is attractive to directly activate cytotoxic lymphocytes or to support their activation by monoclonal antibodies or bispecific T cell engagers. As a perspective, cotargeting of two tumor antigens may allow fine-tuning of antibody cancer therapies. Our proposed combinatorial approach is potentially applicable for many existing immunotherapies but further testing in different preclinical models is necessary to explore the full potential. [ABSTRACT FROM AUTHOR]

Acute kidney injury (AKI) is a complex and heterogeneous disease with high incidence and mortality, posing a serious threat to human life and health. Usually, in clinical practice, AKI is caused by crush injury, nephrotoxin exposure, ischemia-reperfusion injury, or sepsis. Therefore, most AKI models for pharmacological experimentation are based on this. The current research promises to develop new biological therapies, including antibody therapy, non-antibody protein therapy, cell therapy, and RNA therapy, that could help mitigate the development of AKI. These approaches can promote renal repair and improve systemic hemodynamics after renal injury by reducing oxidative stress, inflammatory response, organelles damage, and cell death, or activating cytoprotective mechanisms. However, no candidate drugs for AKI prevention or treatment have been successfully translated from bench to bedside. This article summarizes the latest progress in AKI biotherapy, focusing on potential clinical targets and novel treatment strategies that merit further investigation in future pre-clinical and clinical studies. [ABSTRACT FROM AUTHOR]

Although the six-transmembrane epithelial antigen of prostate 1 (STEAP1) was first identified in advanced prostate cancer, its overexpression is recognized in multiple types of cancer and associated with a poor prognosis. STEAP1 is now drawing attention as a promising therapeutic target because of its tumor specificity and membrane-bound localization. The clinical efficacy of an antibody-drug conjugate targeting STEAP1 in metastatic, castration-resistant, prostate cancer was demonstrated in a phase 1 trial. Furthermore, growing evidence suggests that STEAP1 is an attractive target for immunotherapies such as chimeric antigen receptor-T cell therapy. In this review, we summarize the oncogenic functions of STEAP1 by cancer type. This review also provides new insights into the development of new anticancer strategies targeting STEAP1. [ABSTRACT FROM AUTHOR]

We report 8 cases of persistent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia in patients previously treated with anti-CD20 monoclonal antibodies. Polymerase chain reaction of nasopharyngeal swabs for SARS-CoV-2 was negative in most cases; viral cell cultures confirmed that viable SARS-Co-2 virus was present. Four patients were treated with anti-SARS-CoV-2 hyperimmune globulins with rapid resolution of disease. [ABSTRACT FROM AUTHOR]

Objectives: In this early retrospective cohort study, a total of 26 patients with SARS-CoV-2 were treated with bamlanivimab or casirivimab/imdevimab, and the reduction of the viral load associated with the developed clinical symptoms was analyzed. Methods: Patients in the intervention groups received bamlanivimab or casirivimab/imdevimab. Patients without treatment served as control. Outcomes were assessed by clinical symptoms and change in log viral load from baseline based on the cycle threshold over a period of 18 days. Results: Median log viral load decline was higher in both intervention groups after 3 and 6 days compared to control. However, at later time points, the decline of the viral load was more distinct in the control group. Mild symptoms of COVID-19 were observed in 6.3% of the intervention groups and in no patient of the control. No patients treated with bamlanivimab, 18.8% treated with casirivimab/imdevimab, and 14.2% in the control group developed moderate symptoms. Severe symptoms were recorded only in the control group (14.2%), including one related death. Conclusion: Treatment with monoclonal SARS-CoV-2 antibodies seems to accelerate decline of virus loads, especially in the first 6 days after administration, compared to control. This may be associated with a reduced likeliness of a severe course of COVID-19.

CD99 was demonstrated to be a potential target for antibody therapy on T-acute lymphoblastic leukemia (T-ALL). The ligation of CD99 by certain monoclonal antibodies (mAbs) induced T-ALL apoptosis. However, the molecular basis contributing to the apoptosis of T-ALL upon anti-CD99 mAb engagement remains elusive. In this study, using our generated anti-CD99 mAb clone MT99/3 (mAb MT99/3), mAb MT99/3 engagement strongly induced apoptosis of T-ALL cell lines, but not in non-malignant peripheral blood cells. By transcriptome analysis, upon mAb MT99/3 ligation, 13 apoptosis-related genes, including FOS, TNF, FASLG, BCL2A1, JUNB, SOCS1, IL27RA, PTPN6, PDGFA, NR4A1, SGK1, LPAR5 and LTB, were significantly upregulated. The epitope of CD99 recognized by mAb MT99/3 was then identified as the VDGENDDPRPP at residues 60–70 of CD99, which has never been reported. To the best of our knowledge, this is the first transcriptome data conducted in T-ALL with anti-CD99 mAb engagement. These findings provide new insights into CD99 implicated in the apoptosis of T-ALL. The identification of a new epitope and apoptosis-related genes that relate to the induction of apoptosis by mAb MT99/3 may serve as a new therapeutic target for T-ALL. The anti-CD99 mAb clone MT99/3 might be a candidate for further development of a therapeutic antibody for T-ALL therapy.

The activating receptor natural killer group 2, member D (NKG2D) represents an attractive target for immunotherapy as it exerts a crucial role in cancer immunosurveillance by regulating the activity of cytotoxic lymphocytes. In this study, a panel of novel NKG2D-specific single-chain fragments variable (scFv) were isolated from naïve human antibody gene libraries and fused to the fragment antigen binding (Fab) of rituximab to obtain [CD20×NKG2D] bibodies with the aim to recruit cytotoxic lymphocytes to lymphoma cells. All bispecific antibodies bound both antigens simultaneously. Two bibody constructs, [CD20×NKG2D#3] and [CD20×NKG2D#32], efficiently activated natural killer (NK) cells in co-cultures with CD20+ lymphoma cells. Both bibodies triggered NK cell-mediated lysis of lymphoma cells and especially enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) by CD38 or CD19 specific monoclonal antibodies suggesting a synergistic effect between NKG2D and FcγRIIIA signaling pathways in NK cell activation. The [CD20×NKG2D] bibodies were not effective in redirecting CD8+ T cells as single agents, but enhanced cytotoxicity when combined with a bispecific [CD19×CD3] T cell engager, indicating that NKG2D signaling also supports CD3-mediated T cell activation. In conclusion, engagement of NKG2D with bispecific antibodies is attractive to directly activate cytotoxic lymphocytes or to support their activation by monoclonal antibodies or bispecific T cell engagers. As a perspective, co-targeting of two tumor antigens may allow fine-tuning of antibody cancer therapies. Our proposed combinatorial approach is potentially applicable for many existing immunotherapies but further testing in different preclinical models is necessary to explore the full potential.

Immune checkpoint blockade is a compelling approach in tumor immunotherapy. Blocking inhibitory pathways in T cells has demonstrated clinical efficacy in different types of cancer and may hold potential to also stimulate innate immune responses. A novel emerging potential target for immune checkpoint therapy is leukocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1). LILRB1 belongs to the superfamily of leukocyte immunoglobulin-like receptors and exerts inhibitory functions. The receptor is expressed by a variety of immune cells including macrophages as well as certain cytotoxic lymphocytes and contributes to the regulation of different immune responses by interaction with classical as well as non-classical human leukocyte antigen (HLA) class I molecules. LILRB1 has gained increasing attention as it has been demonstrated to function as a phagocytosis checkpoint on macrophages by recognizing HLA class I, which represents a 'Don't Eat Me!' signal that impairs phagocytic uptake of cancer cells, similar to CD47. The specific blockade of the HLA class I:LILRB1 axis may provide an option to promote phagocytosis by macrophages and also to enhance cytotoxic functions of T cells and natural killer (NK) cells. Currently, LILRB1 specific antibodies are in different stages of preclinical and clinical development. In this review, we introduce LILRB1 and highlight the features that make this immune checkpoint a promising target for cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Background: Despite recent advances in the treatment of aggressive lymphomas, a significant fraction of patients still succumbs to their disease. Thus, novel therapies are urgently needed. As the anti-CD20 antibody rituximab and the CD19-targeting antibody tafasitamab share distinct modes of actions, we investigated if dual-targeting of aggressive lymphoma B-cells by combining rituximab and tafasitamab might increase cytotoxic effects. Methods: Antibody single and combination efficacy was determined investigating different modes of action including direct cytotoxicity, antibody-dependent cellmediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) in in vitro and in vivo models of aggressive B-cell lymphoma comprising diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL). Results: Three different sensitivity profiles to antibody monotherapy or combination treatment were observed in in vitro models: while 1/11 cell lines was primarily sensitive to tafasitamab and 2/11 to rituximab, the combination resulted in enhanced cell death in 8/11 cell lines in at least one mode of action. Treatment with either antibody or the combination resulted in decreased expression of the oncogenic transcription factor MYC and inhibition of AKT signaling, which mirrored the cell line-specific sensitivities to direct cytotoxicity. At last, the combination resulted in a synergistic survival benefit in a PBMChumanized Ramos NOD/SCID mouse model. Conclusion: This study demonstrates that the combination of tafasitamab and rituximab improves efficacy compared to single-agent treatments in models of aggressive B-cell lymphoma in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Abstract Background Clinical data on patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) delta variant are limited, especially on clinical status after the application of antibody therapy. Methods We evaluated clinical status in patients with the SARS-CoV-2 delta variant after BRII-196 and BRII-198 treatment in an infectious disease hospital in China. We collected data on clinical symptoms, laboratory tests, radiological characteristics, viral load, anti-SARS-CoV-2 antibodies, treatment, and outcome. Results In mid-June 2021, 36 patients with delta variant infection were identified in Shenzhen. The most common symptoms at illness onset were cough (30.6%), fever (22.2%), myalgia (16.7%), and fatigue (16.7%). A small number of patients in this study had underlying diseases, including diabetes (5.6%) and hypertension (8.3%). The application of BRII-196 and BRII-198 can rapidly increase anti-SARS-CoV-2 IgG. The median peak IgG levels in the antibody treatment group were 32 times higher than those in the control group (P

Ischaemic neurovascular stroke represents a leading cause of death in the developed world. Preclinical and human epidemiological evidence implicates the corticotropin‐releasing factor (CRF) family of neuropeptides as mediators of acute neurovascular injury pathology. Preclinical investigations of the role of CRF, CRF receptors and CRF‐dependent activation of the hypothalamic–pituitary–adrenal (HPA) axis have pointed toward a tissue‐specific and temporal relationship between activation of these pathways and physiological outcomes. Based on the literature, the major phases of ischaemic stroke aetiology may be separated into an acute phase in which CRF and anti‐inflammatory stress signalling are beneficial and a chronic phase in which these contribute to neural degeneration, toxicity and apoptotic signalling. Significant gaps in knowledge remain regarding the pathway, temporality and systemic impact of CRF signalling and stress biology in neurovascular injury progression. Heterogeneity among experimental designs poses a challenge to defining the apparent reciprocal relationship between neurological injury and stress metabolism. Despite these challenges, it is our opinion that the elucidated temporality may be best matched with an antibody against CRF with a half‐life of days to weeks as opposed to minutes to hours as with small‐molecule CRF receptor antagonists. This state‐of‐the‐art review will take a multipronged approach to explore the expected potential benefit of a CRF antibody by modulating CRF and corticotropin‐releasing factor receptor 1 signalling, glucocorticoids and autonomic nervous system activity. Additionally, this review compares the modulation of CRF and HPA axis activity in neuropsychiatric diseases and their counterpart outcomes post‐stroke and assess lessons learned from antibody therapies in neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

• SARS-CoV-2 viral load can be correlated to the clinical outcomes. • Neutralizing antibodies reduce the viral load, especially in the early stages of the disease. • The viral load reduction of the antibody treatment starts to stagnate after 6 days. • Monoclonal antibodies may prevent severe progression in high-risk patients. In this early retrospective cohort study, a total of 26 patients with SARS-CoV-2 were treated with bamlanivimab or casirivimab/imdevimab, and the reduction of the viral load associated with the developed clinical symptoms was analyzed. Patients in the intervention groups received bamlanivimab or casirivimab/imdevimab. Patients without treatment served as control. Outcomes were assessed by clinical symptoms and change in log viral load from baseline based on the cycle threshold over a period of 18 days. Median log viral load decline was higher in both intervention groups after 3 and 6 days compared to control. However, at later time points, the decline of the viral load was more distinct in the control group. Mild symptoms of COVID-19 were observed in 6.3% of the intervention groups and in no patient of the control. No patients treated with bamlanivimab, 18.8% treated with casirivimab/imdevimab, and 14.2% in the control group developed moderate symptoms. Severe symptoms were recorded only in the control group (14.2%), including one related death. Treatment with monoclonal SARS-CoV-2 antibodies seems to accelerate decline of virus loads, especially in the first 6 days after administration, compared to control. This may be associated with a reduced likeliness of a severe course of COVID-19. [ABSTRACT FROM AUTHOR]

Antibody therapeutics and vaccines for coronavirus disease 2019 (COVID-19) have been approved in many countries, with most being developed based on the original strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 has an exceptional ability to mutate under the pressure of host immunity, especially the immune-dominant spike protein of the virus, which is the target of both antibody drugs and vaccines. Given the continuous evolution of the virus and the identification of critical mutation sites, the World Health Organization (WHO) has named 5 variants of concern (VOCs): 4 are previously circulating VOCs, and 1 is currently circulating (Omicron). Due to multiple mutations in the spike protein, the recently emerged Omicron and descendent lineages have been shown to have the strongest ability to evade the neutralizing antibody (NAb) effects of current antibody drugs and vaccines. The development and characterization of broadly neutralizing antibodies (bNAbs) will provide broad strategies for the control of the sophisticated virus SARS-CoV-2. In this review, we describe how the virus evolves to escape NAbs and the potential neutralization mechanisms that associated with bNAbs. We also summarize progress in the development of bNAbs against SARS-CoV-2, human coronaviruses (CoVs) and other emerging pathogens and highlight their scientific and clinical significance. [ABSTRACT FROM AUTHOR]

Immune checkpoint blockade is a compelling approach in tumor immunotherapy. Blocking inhibitory pathways in T cells has demonstrated clinical efficacy in different types of cancer and may hold potential to also stimulate innate immune responses. A novel emerging potential target for immune checkpoint therapy is leukocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1). LILRB1 belongs to the superfamily of leukocyte immunoglobulin-like receptors and exerts inhibitory functions. The receptor is expressed by a variety of immune cells including macrophages as well as certain cytotoxic lymphocytes and contributes to the regulation of different immune responses by interaction with classical as well as non-classical human leukocyte antigen (HLA) class I molecules. LILRB1 has gained increasing attention as it has been demonstrated to function as a phagocytosis checkpoint on macrophages by recognizing HLA class I, which represents a ‘Don’t Eat Me!’ signal that impairs phagocytic uptake of cancer cells, similar to CD47. The specific blockade of the HLA class I:LILRB1 axis may provide an option to promote phagocytosis by macrophages and also to enhance cytotoxic functions of T cells and natural killer (NK) cells. Currently, LILRB1 specific antibodies are in different stages of pre-clinical and clinical development. In this review, we introduce LILRB1 and highlight the features that make this immune checkpoint a promising target for cancer immunotherapy.

BackgroundDespite recent advances in the treatment of aggressive lymphomas, a significant fraction of patients still succumbs to their disease. Thus, novel therapies are urgently needed. As the anti-CD20 antibody rituximab and the CD19-targeting antibody tafasitamab share distinct modes of actions, we investigated if dual-targeting of aggressive lymphoma B-cells by combining rituximab and tafasitamab might increase cytotoxic effects.MethodsAntibody single and combination efficacy was determined investigating different modes of action including direct cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) in in vitro and in vivo models of aggressive B-cell lymphoma comprising diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL).ResultsThree different sensitivity profiles to antibody monotherapy or combination treatment were observed in in vitro models: while 1/11 cell lines was primarily sensitive to tafasitamab and 2/11 to rituximab, the combination resulted in enhanced cell death in 8/11 cell lines in at least one mode of action. Treatment with either antibody or the combination resulted in decreased expression of the oncogenic transcription factor MYC and inhibition of AKT signaling, which mirrored the cell line-specific sensitivities to direct cytotoxicity. At last, the combination resulted in a synergistic survival benefit in a PBMC-humanized Ramos NOD/SCID mouse model.ConclusionThis study demonstrates that the combination of tafasitamab and rituximab improves efficacy compared to single-agent treatments in models of aggressive B-cell lymphoma in vitro and in vivo.

Rapid upregulation of matrix metalloproteinase 9 (MMP-9) leads to blood-brain barrier (BBB) breakdown following stroke, but no MMP-9 inhibitors have been approved in clinic largely due to their low specificities and side effects. Here, we explored the therapeutic potential of a human IgG monoclonal antibody (mAb), L13, which was recently developed with exclusive neutralizing specificity to MMP-9, nanomolar potency, and biological function, using mouse stroke models and stroke patient samples. We found that L13 treatment at the onset of reperfusion following cerebral ischemia or after intracranial hemorrhage (ICH) significantly reduced brain tissue injury and improved the neurological outcomes of mice. Compared to control IgG, L13 substantially attenuated BBB breakdown in both types of stroke model by inhibiting MMP-9 activity-mediated degradations of basement membrane and endothelial tight junction proteins. Importantly, these BBB-protective and neuroprotective effects of L13 in wild-type mice were comparable to Mmp9 genetic deletion and fully abolished in Mmp9 knockout mice, highlighting the in vivo target specificity of L13. Meanwhile, ex vivo co-incubation with L13 significantly neutralized the enzymatic activities of human MMP-9 in the sera of ischemic and hemorrhagic stroke patients, or in the peri-hematoma brain tissues from hemorrhagic stroke patients. Overall, we demonstrated that MMP-9 exclusive neutralizing mAbs constitute a potential feasible therapeutic approach for both ischemic and hemorrhagic stroke.