Antibody-dependent Cellular Cytotoxicity Research Articles

Natural killer cells as promising candidates in Cancer therapeutics and related immune resistance in tumor microenvironment

Natural killer (NK) cells, as critical components of the innate immune system, have emerged as promising candidates in cancer therapy due to their ability to recognize and destroy tumor cells without prior sensitization. Their mechanisms of action, including perforin-granzyme release and antibody-dependent cellular cytotoxicity (ADCC), position them as versatile agents in cancer immunotherapy. Recent advancements, such as chimeric antigen receptor (CAR)-NK cells and cytokine-based stimulation, have demonstrated enhanced efficacy and reduced side effects compared to conventional immunotherapies. However, the immunosuppressive tumor microenvironment (TME) remains a significant obstacle, imposing challenges like immune checkpoint activation, cytokine suppression, and metabolic constraints that impair NK cell activity. This paper explores the therapeutic potential of NK cells, the challenges of immune resistance in the TME, and emerging strategies to enhance NK cell efficacy. Addressing these challenges is crucial for optimizing NK cell-based treatments and achieving durable responses in cancer patients.

A Vaccine Against Fibroblast Activation Protein Improves Murine Cardiac Fibrosis by Preventing the Accumulation of Myofibroblasts.

Myofibroblasts are primary cells involved in chronic response-induced cardiac fibrosis. Fibroblast activation protein (FAP) is a relatively specific marker of activated myofibroblasts and a potential target molecule. This study aimed to clarify whether a vaccine targeting FAP could eliminate myofibroblasts in chronic cardiac stress model mice and reduce cardiac fibrosis. We coadministered a FAP peptide vaccine with a CpG K3 oligonucleotide adjuvant to male C57/BL6J mice and confirmed an elevation in the anti-FAP antibody titer. After continuous angiotensin II and phenylephrine administration for 28 days, we evaluated the degree of cardiac fibrosis and the number of myofibroblasts in cardiac tissues. We found that cardiac fibrosis was significantly decreased in the FAP-vaccinated mice compared with the angiotensin II and phenylephrine control mice (3.45±1.11% versus 8.62±4.79%; P=4.59×10-3) and that the accumulation of FAP-positive cells was also significantly decreased, as indicated by FAP immunohistochemical staining (4077±1746 versus 7327±1741 cells/mm2; FAP vaccine versus angiotensin II and phenylephrine control; P=6.67×10-3). No systemic or organ-specific inflammation due to antibody-dependent cell cytotoxicity induced by the FAP vaccine was observed. Although the transient activation of myofibroblasts has an important role in maintaining the structural robustness in the process of tissue repair, the FAP vaccine showed no adverse effects in myocardial infarction and skin injury models. Our study demonstrates the FAP vaccine can be a therapeutic tool for cardiac fibrosis.

Sustained Endocytosis Inhibition via Locally-Injected Drug-Eluting Hydrogel Improves ADCC-Mediated Antibody Therapy in Colorectal Cancer.

The epidermal growth factor receptor (EGFR) is a validated therapeutic target for RAS/RAF wild-type colorectal cancer (CRC). However, monoclonal antibody-based anti-EGFR therapies such as cetuximab have limited effectiveness. Herein, it is identified that EGFR internalization is associated with poor treatment response and prognosis in patients with CRC, based on a retrospective analysis of patients treated with cetuximab. It is further demonstrated that the endocytosis inhibitor prochlorperazine (PCZ) can move EGFR, which is hidden inside the cell, to the cell surface to improve therapeutic antibody binding. Thus, a thermosensitive hydrogel co-loaded with cetuximab and PCZ (Gel@Cmab/PCZ) is constructed for sustained inhibition of endocytosis and effective cetuximab delivery. Peritumoral injection of Gel@Cmab/PCZ shows strong antitumor efficacy in subcutaneous and orthotopic CRC tumor models and completely abrogated liver metastasis when combined with chemotherapy. In a humanized patient-derived xenograft model, a single injection of Gel@Cmab/PCZ with one-third of theconventional cetuximab dose achieved 91% tumor growth inhibition, which promoted NK cell infiltration into tumor tissues and their antibody-dependent cell-mediated cytotoxicity effect. This study represents a novel strategy to boost the monoclonal antibody-mediated anti-tumor response in CRC.

Elotuzumab-mediated ADCC with Th1-like Vγ9Vδ2 T cells to disrupt myeloma-osteoclast interaction.

Multiple myeloma (MM) cells and osteoclasts (OCs) activate with each other to cause drug resistance. Human Th1-like Vγ9Vδ2 (γδ) T cells, important effectors against tumors, can be expanded and activated exvivo by the aminobisphosphonate zoledronic acid in combination with IL-2. We previously reported that the expanded γδ T cells effectively targeted and killed OCs as well as MM cells. Because the expanded γδ T cells expressed CD16 on their surface, we investigated the utilization of the expanded γδ T cells for antibody-dependent cellular cytotoxicity (ADCC). Although the expanded γδ T cells alone induced cell death in MM cell lines, the addition of the anti-SLAMF7 monoclonal antibody elotuzumab (ELO) further enhanced their cytotoxic activity only against SLAMF7-expressing MM cell lines and primary MM cells. Intriguingly, ELO was also able to enhance γδ T cell-induced cell death against OCs cultured alone, and against both MM cells and OCs in their coculture settings. SLAMF7 was found to be highly expressed in OCs differentiated invitro from monocytes by receptor activator of nuclear factor-κ B ligand and M-CSF, although monocytes only marginally expressed SLAMF7. These results demonstrate that SLAMF7 is highly expressed in both MM cells and OCs, and that the exvivo-expanded γδ T cells can exert ELO-mediated ADCC against SLAMF7-expressing MM cells and OCs besides their direct cytotoxic activity. Further study is warranted for the innovative utilization of γδ T cells.

SHR-1806, a robust OX40 agonist to promote T cell-mediated antitumor immunity

ABSTRACT Anti-CTLA-4 and anti-PD-1/PD-L1 antibodies have significantly revolutionized cancer immunotherapy. However, the persistent challenge of low patient response rates necessitates novel approaches to overcome immune tolerance. Targeting immunostimulatory signaling may have a better chance of success for its ability to enhance effector T cell (Teff) function and expansion for antitumor immunity. Among various immunostimulatory pathways, the evidence underscores the potential of activating OX40-OX40L signaling to enhance CD8+ T cell generation and maintenance while suppressing regulatory T cells (Tregs) within the tumor microenvironment (TME). In this study, we introduce a potent agonistic anti-OX40 antibody, SHR-1806, designed to target OX40 receptors on activated T cells and amplify antitumor immune responses. SHR-1806 demonstrates a high affinity and specificity for human OX40 protein, eliciting FcγR-mediated agonistic effects, T cell activation, antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) activities in vitro. In human OX40 knock-in mice bearing MC38 tumor, SHR-1806 shows a trend toward a higher potency than the reference anti-OX40 antibody produced in-house, GPX4, an analog of pogalizumab, the most advanced drug candidate developed by Roche. Furthermore, SHR-1806 displays promising anti-tumor activity alone or in combination with toll-like receptor 7 (TLR7) agonist or PD-L1 inhibitor in mouse models. Evaluation of SHR-1806 in rhesus monkeys indicates a favorable safety profile and typical pharmacokinetic characteristics. Thus, SHR-1806 emerges as a robust OX40 agonist with promising therapeutic potential.

In utero human cytomegalovirus infection expands NK-like FcγRIII+ CD8+ T cells that mediate Fc antibody functions.

Human cytomegalovirus (HCMV) profoundly impacts host T and natural killer (NK) cells across the lifespan, yet how this common congenital infection modulates developing fetal immune cell compartments remains underexplored. Using cord blood from neonates with and without congenital HCMV (cCMV) infection, we identify an expansion of Fcγ receptor III (FcγRIII)-expressing CD8+ T cells following HCMV exposure in utero. Most FcγRIII+ CD8+ T cells express the canonical αβ T cell receptor (TCR) but a proportion express non-canonical γδ TCR. FcγRIII+ CD8+ T cells are highly differentiated and have increased expression of NK cell markers and cytolytic molecules. Transcriptional analysis reveals FcγRIII+ CD8+ T cells upregulate T-bet and downregulate BCL11B, known transcription factors that govern T/NK cell fate. We show that FcγRIII+ CD8+ T cells mediate antibody-dependent IFNγ production and degranulation against IgG-opsonized target cells, similar to NK cell antibody-dependent cellular cytotoxicity (ADCC). FcγRIII+ CD8+ T cell Fc effector functions were further enhanced by interleukin-15 (IL-15), as has been observed in neonatal NK cells. Our study reveals that FcγRIII+ CD8+ T cells elicited in utero by HCMV infection can execute Fc-mediated effector functions bridging cellular and humoral immunity and may be a promising target for antibody-based therapeutics and vaccination in early life.

Efficacy and safety of the anti-IL1RAP antibody nadunolimab (CAN04) in combination with gemcitabine and nab-paclitaxel in patients with advanced/metastatic pancreatic cancer.

Interleukin (IL)-1 pathway upregulation is implicated in pancreatic ductal adenocarcinoma (PDAC) progression, therapy resistance, and survival. Nadunolimab is an IL-1 receptor accessory protein (IL1RAP)-targeting antibody with enhanced antibody-dependent cellular cytotoxicity that blocks IL-1α/IL-1β signaling. We investigated efficacy and safety of nadunolimab in PDAC, in combination with gemcitabine/nab-paclitaxel (GN). Patients with previously untreated locally advanced/metastatic PDAC received nadunolimab (1.0-7.5 mg/kg) every two weeks with standard GN. The primary objective was safety; secondary objectives were anti-tumor response, progression-free survival (PFS) and overall survival (OS). Correlations between serum and tumor biomarkers and clinical response were explored. 76 patients were enrolled, median age 63 years (range 43-89), 42% female, 97% with metastatic disease, 9% having received adjuvant chemotherapy. The most frequent Grade ≥3 adverse event was neutropenia (66%), typically during Cycle 1. Infusion-related reactions occurred in 29% (Grade 3, 3%). Only 1 of 76 patients had grade 3 or above peripheral neuropathy. No marked dose-dependent differences in safety or efficacy were observed between the four dose groups. Median OS overall was 13.2 months (95%CI 10.6-15.5) and 1-year survival was 58%. Median iPFS (iRECIST) was 7.2 months (95%CI 5.2-8.5). Treatment efficacy was higher in patients with high versus low tumor baseline IL1RAP expression (OS 14.2 vs 10.6 months, p=0.026). A reduction in serum IL-8 on treatment correlated with prolonged OS. Nadunolimab combined with GN shows promising efficacy and manageable safety in locally advanced/metastatic PDAC. Higher tumor baseline IL1RAP expression correlated with better outcome.

Dissecting immunological mechanisms underlying influenza viral nucleoprotein-induced mucosal immunity against diverse viral strains

ABSTRACT The nucleoprotein (NP) of type A influenza virus (IAV) is highly conserved across all virus strains, making it an attractive candidate antigen for universal vaccines. While various studies have explored NP-induced mucosal immunity, here we interrogated the mechanistic differences between intramuscular (IM) and intranasal (IN) delivery of a recombinant adenovirus carrying NP fused with a bifunctional CD40 ligand. Despite being less effective than IM delivery in inducing systemic cellular immune responses and antibody-dependent cellular cytotoxicity (ADCC), IN immunization elicited superior antigen-specific recall humoral and cellular response in the nasal associated lymphoid tissue (NALT) of the upper respiratory tract, the initial site of immune recognition and elimination of inhaled pathogens. IN vaccination also induced significantly stronger pulmonary T cell responses in the lower respiratory tract than IM vaccination, in particular the CD8 T cells. Moreover, blocking lymphocyte circulation abrogated IM but not IN immunization induced protection, illustrating the critical role of local memory immune response upon viral infection. Notably, the CD40-targeted nasal delivery not only improved the magnitude but also the breadth of protection, including against lethal challenge with a newly isolated highly pathogenic avian H5N1 strain. These findings are informative for the design of universal mucosal vaccines, where the predominant mode of protection is independent of neutralizing antibodies.

Discovery of a single-subunit oligosaccharyltransferase that enables glycosylation of full-length IgG antibodies in Escherichia coli.

Human immunoglobulin G (IgG) antibodies are one of the most important classes of biotherapeutic agents and undergo glycosylation at the conserved N297 site in the C H 2 domain, which is critical for IgG Fc effector functions and anti-inflammatory activity. Hence, technologies for producing authentically glycosylated IgGs are in high demand. While attempts to engineer Escherichia coli for this purpose have been described, they have met limited success due in part to the lack of available oligosaccharyltransferase (OST) enzymes that can install N- linked glycans within the QYNST sequon of the IgG C H 2 domain. Here, we identified a previously uncharacterized single-subunit OST (ssOST) from the bacterium Desulfovibrio marinus that exhibited greatly relaxed substrate specificity and, as a result, was able to catalyze glycosylation of native C H 2 domains in the context of both a hinge-Fc fragment and a full-length IgG. Although the attached glycans were bacterial in origin, conversion to a homogeneous, asialo complex-type G2 N -glycan at the QYNST sequon of the E. coli -derived hinge-Fc was achieved via chemoenzymatic glycan remodeling. Importantly, the resulting G2-hinge-Fc exhibited strong binding to human FcγRIIIa (CD16a), one of the most potent receptors for eliciting antibody-dependent cellular cytotoxicity (ADCC). Taken together, the discovery of a unique ssOST from D. marinus provides previously unavailable biocatalytic capabilities to the bacterial glycoprotein engineering toolbox and opens the door to using E. coli for the production and glycoengineering of human IgGs and fragments derived thereof.

Bendamustine–rituximab elicits dual tumoricidal and immunomodulatory responses via cGAS–STING activation in diffuse large B-cell lymphoma

BackgroundBendamustine–rituximab (BR) therapy stands out as a promising alternative for elderly patients with diffuse large B-cell lymphoma (DLBCL), demonstrating notable efficacy when conventional regimens pose challenges. Despite its clinical success,...

Nonclinical Similarity of the Biosimilar Candidate ABP 938 with Aflibercept Reference Product.

ABP 938 is being developed as a biosimilar to Eylea® (aflibercept reference product [RP]), an anti-vascular endothelial growth factor (VEGF) drug used in the management of retinal diseases. Previously, a comparative analytical similarity assessment demonstrated that ABP 938 and aflibercept RP have the same amino acid sequence and exhibit similar higher-order structure and biological activity. The nonclinical studies described here were designed to assess the in vitro pharmacology and the in vivo pharmacokinetics (PK), toxicokinetics (TK), and safety profiles of ABP 938 compared to aflibercept RP. In vitro target-binding kinetics and affinity for VEGF-A and placental growth factor (PIGF) isoforms were evaluated using surface plasmon resonance (SPR). Effector functions were assessed by cell-based assays. PK was evaluated in a nonterminal intravitreal (IVT) ocular distribution study in rabbits. Safety was assessed in a 1-month IVT study in cynomolgus monkeys. SPR results demonstrated that ABP 938 is similar to aflibercept RP in binding kinetics and affinity for VEGF-A111, VEGF-A121, VEGF-A165, VEGF-A189, PlGF-1, and PlGF-2 isoforms. No antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, or complement-dependent cytotoxicity was observed with ABP 938 and aflibercept RP. Results from thenonterminal ocular distribution study in rabbits indicated that there were no meaningful differences in the distribution kinetics between intravitreally injected ABP 938 and aflibercept RP. Additionally, there was no evidence of ocular or systemic toxicity associated with IVT administration of ABP 938 in a repeat-dose, 1-month toxicology study in cynomolgus monkeys; toxicokinetic and toxicology profiles were similar to aflibercept RP. This integrated assessment of results from the in vitro pharmacology assessment and in vivo PK and TK/toxicology profiles formed the nonclinical portion of the totality of evidence demonstrating ABP938 is a biosimilar to aflibercept RP.

A Cancer-Specific Anti-Podoplanin Monoclonal Antibody, PMab-117-mG2a Exerts Antitumor Activities in Human Tumor Xenograft Models.

Podoplanin (PDPN) overexpression is associated with poor clinical outcomes in various tumors. PDPN is involved in malignant tumor progression by promoting invasiveness and metastasis. Therefore, PDPN is considered a promising target of monoclonal antibody (mAb)-based therapy. Because PDPN also plays an essential role in normal cells such as kidney podocytes, cancer specificity is required to reduce adverse effects on normal cells. We developed a cancer-specific mAb (CasMab) against PDPN, PMab-117 (rat IgM, kappa), by immunizing rats with PDPN-overexpressed glioblastoma cells. The recombinant mouse IgG2a-type PMab-117 (PMab-117-mG2a) reacted with the PDPN-positive tumor PC-10 and LN319 cells but not with PDPN-knockout LN319 cells in flow cytometry. PMab-117-mG2a did not react with normal kidney podocytes and normal epithelial cells from the lung bronchus, mammary gland, and corneal. In contrast, one of the non-CasMabs against PDPN, NZ-1, showed high reactivity to PDPN in both tumor and normal cells. Moreover, PMab-117-mG2a exerted antibody-dependent cellular cytotoxicity in the presence of effector splenocytes. In the human tumor xenograft models, PMab-117-mG2a exhibited potent antitumor effects. These results indicated that PMab-117-mG2a could be applied to antibody-based therapy against PDPN-expressing human tumors while reducing the adverse effects.

Knockdowns of CD3zeta Chain in Primary NK Cells Illustrate Modulation of Antibody-Dependent Cellular Cytotoxicity Against Human Immunodeficiency Virus-1.

Multifaceted natural killer (NK) cell activities are indispensable for controlling human immunodeficiency virus (HIV)-1 transmission and pathogenesis. Among the diverse functions of NK cells, antibody-dependent cellular cytotoxicity (ADCC) has been shown to predict better HIV-1 protection. ADCC is initiated by the engagement of an Fc γ receptor CD16 with an Fc portion of the antibody, leading to phosphorylation of the CD3 ζ chain (CD3ζ) and Fc receptor γ chain (FcRγ) as well as downstream signaling activation. Though CD3ζ and FcRγ were thought to have overlapping roles in NK cell ADCC, several groups have reported that CD3ζ-mediated signals trigger a more robust ADCC. However, few studies have illustrated the direct contribution of CD3ζ in HIV-1-specific ADCC. To further understand the roles played by CD3ζ in HIV-1-specific ADCC, we developed a CD3ζ knockdown system in primary human NK cells. We observed that HIV-1-specific ADCC was inhibited by CD3ζ perturbation. In summary, we demonstrated that CD3ζ is important for eliciting HIV-1-specific ADCC, and this dynamic can be utilized for NK cell immunotherapeutics against HIV-1 infection and other diseases.

First-in-Human Study of BAT4406F, an ADCC-Enhanced Fully Humanized Anti-CD20 Monoclonal Antibody in Patients With Neuromyelitis Optica Spectrum Disorders.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare debilitating autoimmune disease of the central nervous system (CNS). This is the first-in-human dose-escalation Phase I clinical study of BAT4406F, an antibody-dependent cell-mediated cytotoxicity (ADCC)-enhanced fully humanized anti-CD20 monoclonal antibody, in Chinese NMOSD patients. Using a "3 + 3" design and based on the planned algorithm of dose escalation, the enrolled NMOSD patients were sequentially assigned to one of the five dose-escalation cohorts of BAT4406F with a single intravenous dose, and were then followed for a 6-month observation period. The maximum tolerated dose (MTD) and dose-limiting toxicity (DLT), safety, pharmacokinetics (PK), pharmacodynamics, and immunogenicity of BAT4406F were investigated, and the efficacy of BAT4406F in NMOSD was also preliminarily explored. Fifteen Chinese NMOSD patients were enrolled to receive BAT4406F of escalated doses ranging from 20 to 750 mg. No subjects experienced DLT at the studied doses. BAT4406F injection exhibited favorable safety, with most of the adverse events (AE) of CTCAE Grade 1 or 2 in severity, and no Grade ≥ 3 adverse drug reactions (ADR) or serious adverse reactions occurred in any subjects. With the dose increase of BAT4406F, the maximum plasma concentration (Cmax), area under concentration-time curve from 0 to the last measurable timepoint (AUC0-t) and area under concentration-time curve from 0 to infinity (AUC0-inf) showed an increasing trend, whereas the mean clearance (CLt), terminal elimination rate (λZ), and apparent volume of distribution (Vd) decreased. The mean elimination half-life (T1/2) was ranged from 9.0-16.4 days. PK profile of BAT4406F was generally nonlinear. BAT4406F led to a rapid and significant B-cell depletion in all dose groups. Single administration of 500 mg or 750 mg maintains the CD19+ B lymphocyte count below 10/μL within the whole 6-month observation period. Three subjects were antidrug antibody (ADA) positive and all of them were neutralizing antibody (NAb)-negative. On day 99/180 postdose, several groups had decreased expanded disability status scale (EDSS) scores compared to baseline. During the observation period, NMOSD relapse occurred in two patients (13.3%) and the other 13 (86.7%) subjects remained relapse free. BAT4406F was well tolerated at doses up to 750 mg and showed an expected pharmacodynamic effect of significant and long-term depletion of CD19+ B lymphocytes. It has also shown preliminary evidence of activity in NMOSD maintenance treatment, warranting further investigations. ClinicalTrials.gov identifier: NCT04146285.

Enterovirus Antibodies: Friends and Foes.

Enteroviruses (EV) initiate replication by binding to their cellular receptors, leading to the uncoating and release of the viral genome into the cytosol of the host cell. Neutralising antibodies (NAbs) binding to epitopes on enteroviral capsid proteins can inhibit this infectious process through several mechanisms of neutralisation in vitro. Fc-mediated antibody effector functions such as antibody-dependent cell-mediated cytotoxicity and antibody-dependent cellular phagocytosis have also been described for some EV. However, antibody binding to virions does not always result in viral neutralisation. Non-neutralising antibodies, or sub-neutralising concentrations of antibodies, can enhance infection of viruses, leading to more severe pathologies. This phenomenon, known as antibody-dependent enhancement (ADE) of infection, has been described in vitro and/or in vivo for EV including poliovirus, coxsackievirus B and EV-A71. It has been shown that ADE of EV infection is mediated by FcγRs expressed by monocytes, macrophages, B lymphocytes and granulocytes. Antibodies play a crucial role in the diagnosis and monitoring of infections. They are valuable markers that have been used to establish a link between enteroviral infection and chronic diseases such as type 1 diabetes. Monoclonal and polyclonal antibodies targeting enteroviral proteins have been developed and shown to be effective to prevent or combat EV infections in vitro and in vivo. In addition, vaccines are under development, and clinical trials of vaccines are underway or have been completed, providing hope for the prevention of diseases due to EV. However, the ADE of the infection should be considered in the development of anti-EV antibodies or safe vaccines.

Pyrotinib and trastuzumab combination treatment synergistically overcomes HER2 dependency in HER2-positive breast cancer: insights from the PHILA trial

The PHILA study suggests that pyrotinib, trastuzumab, and docetaxel significantly improved progression-free survival (PFS) compared with placebo, trastuzumab, and docetaxel in patients with untreated HER2-positive metastatic breast cancer. In this study, we aimed to investigate the synergistic mechanisms of pyrotinib plus trastuzumab and provide further insights for the PHILA trial. The invitro activity of combination treatments was assessed through cell biological and biochemical experiments. The invivo efficacy was evaluated in cell-derived xenografts, a TUBO tumour model, and one clinical case. Next-generation sequencing was performed on circulating tumour DNA (ctDNA) from patients in the PHILA trial. The combination of pyrotinib and trastuzumab more effectively inhibited cell growth than pyrotinib or trastuzumab alone in models of HER2-dependent breast cancer. It potentiated membrane HER2 ubiquitination and downregulation, which resulted in a comprehensive blockade of the HER2 signalling pathway. The pyrotinib-altered membrane HER2 levels had no significant effect on trastuzumab-mediated antibody-dependent cell-mediated cytotoxicity (ADCC). We further validated the synergistic mechanisms in TUBO tumours and one clinical case, rather than models of HCC1954cells harbouring the PIK3CA H1047R mutation. Similarly, in our centre cohort of the PHILA study, patients with genetic alterations in the HER2 signalling cascade had significantly shorter median PFS than individuals with the wild-type pathway. Our findings underscore the robust synergy between pyrotinib and trastuzumab in overcoming HER2 dependency and provide a rationale for pyrotinib, trastuzumab, and docetaxel as one of the optimal choices for patients with untreated HER2-positive metastatic breast cancer, who are dependent on the HER2 signalling cascade. This work was supported by the National Key Research and Development Program of China (2021YFF1201300), the National Natural Science Foundation of China (82172875), the CAMS Innovation Fund for Medical Sciences (CIFMS) (2022-I2M-2-001), and the Joint Innovative Fund of Beijing Natural Science Foundation and Changping District (L234004).

Autoimmune haemolytic anaemias.

Adult autoimmune haemolytic anaemias (AIHAs) include different subtypes of a rare autoimmune disease in which autoantibodies targeting autoantigens expressed on the membrane of autologous red blood cells (RBCs) are produced, leading to their accelerated destruction. In the presence of haemolytic anaemia, the direct antiglobulin test is the cornerstone of AIHA diagnosis. AIHAs are classified according to the isotype and the thermal optimum of the autoantibody into warm (wAIHAs), cold and mixed AIHAs. wAIHAs, the most frequent type of AIHAs, are associated with underlying conditions in ~50% of cases. In wAIHA, IgG autoantibody reacts with autologous RBCs at 37 °C, leading to antibody-dependent cell-mediated cytotoxicity and increased phagocytosis of RBCs in the spleen. Cold AIHAs include cold agglutinin disease (CAD) and cold agglutinin syndrome (CAS) when there is an underlying condition. CAD and cold agglutinin syndrome are IgM cold antibody-driven AIHAs characterized by classical complement pathway-mediated haemolysis. The management of wAIHAs has long been based around corticosteroids and splenectomy and on symptomatic measures and non-specific cytotoxic agents for CAD. Rituximab and the development of complement inhibitors, such as the anti-C1s antibody sutimlimab, have changed the therapeutic landscape of AIHAs, and new promising targeted therapies are under investigation.

Differences in IgG afucosylation between groups with and without carotid atherosclerosis

BackgroundA previous study demonstrated that N-glycosylation profiles of IgG are associated with subclinical atherosclerosis in a British population. However, the generalisability of this finding to other ethnic groups remains to be investigated, and it has yet to account for additional traditional atherosclerotic risk factors. The present study, thus, aims to explore IgG N-glycosylation profiles in Han Chinese with atherosclerosis, and their potential role in atherosclerosis, while controlling for traditional atherosclerotic risk factors.MethodsData of this case-control study were obtained from an established umbrella Health Examination Cohort Study (registration number: ChiCTR2100048740). The investigation was conducted at the Health Care Centre of the First Affiliated Hospital of Shantou University Medical College in China, from August 1, 2021, to July 31, 2022. A sample of 69 carotid atherosclerosis (CAS) cases was recruited from the umbrella cohort, along with 69 controls without carotid atherosclerosis, matched by traditional atherosclerosis-related risk factors, including gender, age, smoking, alcohol consumption, hypertension, diabetes, dyslipidemia and obesity. Subsequently, serum IgG N-glycosylation was profiled using Ultra-Performance Liquid Chromatography.ResultsAfter propensity score matching, the relative abundance of IgG fucosylation in CAS cases was significantly lower than that in controls [95.32 (92.96, 95.99) vs. 95.96 (94.70, 96.58), P = 0.022]. The traditional atherosclerosis-related risk factors showed no statistically significant difference between CAS cases and controls (P > 0.05).ConclusionsThe reduced fucosylation of IgG in CAS cases underscores the pivotal role of afucosylation in CAS. Enhancing the inflammatory capability of IgG via initiating antibody-dependent cell-mediated cytotoxicity could be the potential mechanism behind this, which should be further verified by functional studies.

Asciminib stands out as the superior tyrosine kinase inhibitor to combine with anti-CD20 monoclonal antibodies for the treatment of CD20+ Philadelphia-positive B-cell precursor acute lymphoblastic leukemia in preclinical models.

Philadelphia chromosome-positive B-cell precursor acute lymphoblastic leukemia (Ph+ BCP-ALL) is a high-risk subtype of acute lymphoblastic leukemia characterized by the presence of the BCR::ABL1 fusion gene. Tyrosine kinase inhibitors (TKI) combined with chemotherapy are established as the first-line treatment. Additionally, rituximab, an anti-CD20 monoclonal antibody is administered to adult BCP-ALL patients with ≥20% CD20+ blasts. In this study, we observed a marked prevalence of CD20 expression in patients diagnosed with Ph+ BCP-ALL, indicating a potential widespread clinical application of rituximab in combination with TKI. Consequently, we examined the influence of TKI on the antitumor effectiveness of anti-CD20 monoclonal antibodies by evaluating levels of CD20 on the cell surface and conducting in vitro functional assays. All tested TKI were found to uniformly downregulate CD20 on leukemic cells, diminishing the efficacy of rituximab-mediated complement- dependent cytotoxicity. Interestingly, these TKI displayed varied effects on natural killer (NK) cell-mediated antibody- dependent cytotoxicity and macrophage phagocytic function. While asciminib demonstrated no inhibition of effector cell functions, dasatinib notably suppressed the anti-CD20-monoclonal antibody-mediated NK cell cytotoxicity and macrophage phagocytosis of BCP-ALL cells. Dasatinib and ponatinib also decreased NK cell degranulation in vitro. Importantly, oral administration of dasatinib, but not asciminib, compromised NK cell activity in patients' blood, as determined by an ex vivo degranulation assay. Our results indicate that asciminib might be preferred over other TKI for combination therapy with anti-CD20 monoclonal antibodies.

Trastuzumab-Mediated Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) Enhances Natural Killer Cell Cytotoxicity in HER2-Overexpressing Ovarian Cancer.

Ovarian cancer is the deadliest gynecologic cancer. Although human epidermal growth factor receptor-2 (HER2) overexpression, a poor prognostic molecular marker in ovarian cancer, is found in almost 30% of ovarian cancer cases, there are no established therapies for HER2-overexpressing ovarian cancer. In this study, we investigated the efficacy of combined samfenet, a biosimilar compound of trastuzumab, and natural killer (NK) cells in preclinical model of HER2-overexpressing ovarian cancer. Firstly, we screened the HER2 expression in three ovarian cancer cell lines and eight ovarian cancer patient-derived tumor xenograft (PDTX) samples. Then, immunohistochemistry and silver in situ hybridization (SISH) were performed following clinical criteria. HER2-overexpressing cells exhibited the highest sensitivity to samfenet compared with low-HER2-expressing cells. In addition, the combination of samfenet with natural killer (NK) cells resulted in significantly enhanced sensitivity to HER2-overexpressing cells and showed a significant antitumor effect on PDTX mice compared with monotherapy. It is known that anti-HER2-humanized IgG1 monoclonal antibodies, including trastuzumab, induce antibody-dependent cellular cytotoxicity (ADCC). Consequently, the combination of samfenet with NK cells demonstrated NK cell-mediated ADCC, as confirmed using an in vitro NK cytotoxicity assay and in vivo antitumor efficacy. A transferase dUTP nick end labeling (TUNEL) assay using xenografted tumors further supported the ADCC effects based on the increase in the number of apoptotic cells in the combination group. Furthermore, high HER2 expression was associated with shorter progression-free survival and overall survival based on public mRNA expression data. In this study, we demonstrated that the combination of samfenet and NK cell therapy could be a promising treatment strategy for patients with HER2-overexpressing ovarian cancer, through ADCC effects. Therefore, this study supports a rationale for further clinical studies of the combination of samfenet and NK cells as a therapy for patients with HER2-overexpressing ovarian cancer.