Scientific Resources

Multiple myeloma is an incurable malignancy of plasma cells resulting from impaired terminal B cell development. Almost all patients with multiple myeloma eventually have a relapse. Many studies have demonstrated the importance of the various genomic mutations that characterize multiple myeloma as a complex heterogeneous disease. In recent years,next-generation sequencing has been used to identify the genomic mutation landscape and clonal heterogeneity of multiple myeloma. This is the first study,a prospective observational study,to identify somatic mutations in plasma cell disorders in the Thai population using targeted next-generation sequencing. Twenty-seven patients with plasma cell disorders were enrolled comprising 17 cases of newly diagnosed multiple myeloma,5 cases of relapsed/refractory multiple myeloma,and 5 cases of other plasma cell disorders. The pathogenic mutations were found in 17 of 27 patients. Seventy percent of those who had a mutation (12/17 patients) habored a single mutation,whereas the others had more than one mutation. Fifteen pathogenic mutation genes were identified: ATM,BRAF,CYLD,DIS3,DNMT3A,FBXW7,FLT3,GNA13,IRF4,KMT2A,NRAS,SAMHD1,TENT5C,TP53,and TRAF3. Most have previously been reported to be involved in the RAS/MAPK pathway,the nuclear factor kappa B pathway,the DNA-repair pathway,the CRBN pathway,tumor suppressor gene mutation,or an epigenetic mutation. However,the current study also identified mutations that had not been reported to be related to myeloma: GNA13 and FBXW7. Therefore,a deep understanding of molecular genomics would inevitably improve the clinical management of plasma cell disorder patients,and the increased knowledge would ultimately result in better outcomes for the patients. View Publication

BACKGROUND Lymphoid neoplasms,including multiple myeloma (MM),non-Hodgkin lymphoma (NHL),and NK/T cell neoplasms,are a major cause of blood cancer morbidity and mortality. CD38 (cyclic ADP ribose hydrolase) is a transmembrane glycoprotein expressed on the surface of plasma cells and MM cells. The high expression of CD38 across MM and other lymphoid malignancies and its restricted expression in normal tissues make CD38 an attractive target for immunotherapy. CD38-targeting antibodies,like daratumumab,have been approved for the treatment of MM and tested against lymphoma and leukemia in multiple clinical trials. METHODS We generated chimeric antigen receptor (CAR) T cells targeting CD38 and tested its cytotoxicity against multiple CD38high and CD38low lymphoid cancer cells. We evaluated the synergistic effects of all-trans retinoic acid (ATRA) and CAR T cells or daratumumab against cancer cells and xenograft tumors. RESULTS CD38-CAR T cells dramatically inhibited the growth of CD38high MM,mantle cell lymphoma (MCL),Waldenstrom's macroglobulinemia (WM),T-cell acute lymphoblastic leukemia (T-ALL),and NK/T-cell lymphoma (NKTCL) in vitro and in mouse xenografts. ATRA elevated CD38 expression in multiple CD38low cancer cells and enhanced the anti-tumor activity of daratumumab and CD38-CAR T cells in xenograft tumors. CONCLUSIONS These findings may expand anti-CD38 immunotherapy to a broad spectrum of lymphoid malignancies and call for the incorporation of ATRA into daratumumab or other anti-CD38 immunological agents for cancer therapy. View Publication

Chimeric antigen receptor (CAR) T-cell therapy has led to tremendous successes in the treatment of B-cell malignancies. However,a large fraction of treated patients relapse,often with disease expressing reduced levels of the target antigen. Here,we report that exposing CD19+ B-cell acute lymphoblastic leukemia (B-ALL) cells to CD19 CAR T cells reduced CD19 expression within hours. Initially,CD19 CAR T cells caused clustering of CD19 at the T cell-leukemia cell interface followed by CD19 internalization and decreased CD19 surface expression on the B-ALL cells. CD19 expression was then repressed by transcriptional rewiring. Using single-cell RNA sequencing and single-cell assay for transposase-accessible chromatin using sequencing,we demonstrated that a subset of refractory CD19low cells sustained decreased CD19 expression through transcriptional programs of physiologic B-cell activation and germinal center reaction. Inhibiting B-cell activation programs with the Bruton's tyrosine kinase inhibitor ibrutinib increased the cytotoxicity of CD19 CAR T cells without affecting CAR T-cell viability. These results demonstrate transcriptional plasticity as an underlying mechanism of escape from CAR T cells and highlight the importance of combining CAR T-cell therapy with targeted therapies that aim to overcome this plasticity. See related Spotlight by Zhao and Melenhorst,p. 1040. View Publication

NK cells utilize a large array of receptors to screen their surroundings for aberrant or virus-infected cells. Given the vast diversity of receptors expressed on NK cells we seek to identify receptors involved in the recognition of HIV-1-infected cells. By combining an unbiased large-scale screening approach with a functional assay,we identify TRAIL to be associated with NK cell degranulation against HIV-1-infected target cells. Further investigating the underlying mechanisms,we demonstrate that TRAIL is able to elicit multiple effector functions in human NK cells independent of receptor-mediated induction of apoptosis. Direct engagement of TRAIL not only results in degranulation but also IFN$\gamma$ production. Moreover,TRAIL-mediated NK cell activation is not limited to its cognate death receptors but also decoy receptor I,adding a new perspective to the perceived regulatory role of decoy receptors in TRAIL-mediated cytotoxicity. Based on these findings,we propose that TRAIL not only contributes to the anti-HIV-1 activity of NK cells but also possesses a multifunctional role beyond receptor-mediated induction of apoptosis,acting as a regulator for the induction of different effector functions. View Publication

Tuberculosis is a leading cause of death in mankind due to infectious agents,and Mycobacterium tuberculosis (Mtb) infects and survives in macrophages (MФs). Although MФs are a major niche,myeloid-derived suppressor cells (MDSCs) are an alternative site for pathogen persistence. Both MФs and MDSCs express varying levels of leukocyte immunoglobulin-like receptor B (LILRB),which regulate the myeloid cell suppressive function. Herein,we demonstrate that antagonism of LILRB2 by a monoclonal antibody (mab) induced a switch of human MDSCs towards an M1-macrophage phenotype,increasing the killing of intracellular Mtb. Mab-mediated antagonism of LILRB2 alone and its combination with a pharmacological blockade of SHP1/2 phosphatase increased proinflammatory cytokine responses and phosphorylation of ERK1/2,p38 MAPK,and NF-kB in Mtb-infected MDSCs. LILRB2 antagonism also upregulated anti-mycobacterial iNOS gene expression and an increase in both nitric oxide and reactive oxygen species synthesis. Because genes associated with the anti-mycobacterial function of M1-MФs were enhanced in MDSCs following mab treatment,we propose that LILRB2 antagonism reprograms MDSCs from an immunosuppressive state towards a pro-inflammatory phenotype that kills Mtb. LILRB2 is therefore a novel therapeutic target for eradicating Mtb in MDSCs. View Publication

Na{\{i}}ve T cell activation in secondary lymphoid organs such as lymph nodes (LNs) occurs upon recognition of cognate antigen presented by antigen presenting cells (APCs). T cell activation requires cytoskeleton rearrangement and sustained interactions with APCs. Enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) proteins are a family of cytoskeletal effector proteins responsible for actin polymerization and are frequently found at the leading edge of motile cells. Ena/VASP proteins have been implicated in motility and adhesion in various cell types but their role in primary T cell interstitial motility and activation has not been explored. Our goal was to determine the contribution of Ena/VASP proteins to T cell-APC interactions T cell activation and T cell expansion in vivo. Our results showed that na{\"{i}}ve T cells from Ena/VASP-deficient mice have a significant reduction in antigen-specific T cell accumulation following Listeria monocytogenes infection. The kinetics of T cell expansion impairment were further confirmed in Ena/VASP-deficient T cells stimulated via dendritic cell immunization. To investigate the cause of this T cell expansion defect we analyzed T cell-APC interactions in vivo by two-photon microscopy and observed fewer Ena/VASP-deficient na{\"{i}}ve T cells interacting with APCs in LNs during priming. We also determined that Ena/VASP-deficient T cells formed conjugates with significantly less actin polymerization at the T cell-APC synapse and that these conjugates were less stable than their WT counterparts. Finally we found that Ena/VASP-deficient T cells have less LFA-1 polarized to the T cell-APC synapse. Thus we conclude that Ena/VASP proteins contribute to T cell actin remodeling during T cell-APC interactions which promotes the initiation of stable T cell conjugates during APC scanning. Therefore Ena/VASP proteins are required for efficient activation and expansion of T cells in vivo." View Publication

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages BA.2.12.1,BA.4 and BA.5 exhibit higher transmissibility than the BA.2 lineage1. The receptor binding and immune-evasion capability of these recently emerged variants require immediate investigation. Here,coupled with structural comparisons of the spike proteins,we show that BA.2.12.1,BA.4 and BA.5 (BA.4 and BA.5 are hereafter referred collectively to as BA.4/BA.5) exhibit similar binding affinities to BA.2 for the angiotensin-converting enzyme 2 (ACE2) receptor. Of note,BA.2.12.1 and BA.4/BA.5 display increased evasion of neutralizing antibodies compared with BA.2 against plasma from triple-vaccinated individuals or from individuals who developed a BA.1 infection after vaccination. To delineate the underlying antibody-evasion mechanism,we determined the escape mutation profiles2,epitope distribution3 and Omicron-neutralization efficiency of 1,640 neutralizing antibodies directed against the receptor-binding domain of the viral spike protein,including 614 antibodies isolated from people who had recovered from BA.1 infection. BA.1 infection after vaccination predominantly recalls humoral immune memory directed against ancestral (hereafter referred to as wild-type (WT)) SARS-CoV-2 spike protein. The resulting elicited antibodies could neutralize both WT SARS-CoV-2 and BA.1 and are enriched on epitopes on spike that do not bind ACE2. However,most of these cross-reactive neutralizing antibodies are evaded by spike mutants L452Q,L452R and F486V. BA.1 infection can also induce new clones of BA.1-specific antibodies that potently neutralize BA.1. Nevertheless,these neutralizing antibodies are largely evaded by BA.2 and BA.4/BA.5 owing to D405N and F486V mutations,and react weakly to pre-Omicron variants,exhibiting narrow neutralization breadths. The therapeutic neutralizing antibodies bebtelovimab4 and cilgavimab5 can effectively neutralize BA.2.12.1 and BA.4/BA.5,whereas the S371F,D405N and R408S mutations undermine most broadly sarbecovirus-neutralizing antibodies. Together,our results indicate that Omicron may evolve mutations to evade the humoral immunity elicited by BA.1 infection,suggesting that BA.1-derived vaccine boosters may not achieve broad-spectrum protection against new Omicron variants. View Publication

Type 1 diabetes is an autoimmune disease with no cure,where clinical translation of promising therapeutics has been hampered by the reproducibility crisis. Here,short-term administration of an antagonist to the receptor for advanced glycation end products (sRAGE) protected against murine diabetes at two independent research centers. Treatment with sRAGE increased regulatory T cells (Tregs) within the islets,pancreatic lymph nodes,and spleen,increasing islet insulin expression and function. Diabetes protection was abrogated by Treg depletion and shown to be dependent on antagonizing RAGE with use of knockout mice. Human Tregs treated with a RAGE ligand downregulated genes for suppression,migration,and Treg homeostasis (FOXP3,IL7R,TIGIT,JAK1,STAT3,STAT5b,CCR4). Loss of suppressive function was reversed by sRAGE,where Tregs increased proliferation and suppressed conventional T-cell division,confirming that sRAGE expands functional human Tregs. These results highlight sRAGE as an attractive treatment to prevent diabetes,showing efficacy and reproducibility at multiple research centers and in human T cells. View Publication

The various stages of epithelial-mesenchymal transition (EMT) generate phenotypically heterogeneous populations of cells. Here,we detail a dual recombinase lineage tracing system using a transgenic mouse model of metastatic breast cancer to trace and characterize breast cancer cells at different EMT stages. We describe analytical steps to label cancer cells at an early partial or a late full EMT state,followed by tracking their behavior in tumor slice cultures. We then characterize their transcriptome by five-cell RNA sequencing. View Publication

BACKGROUND & AIMS N6-Methyladenosine (m6A) is the most prevalent RNA modification and recognized as an important epitranscriptomic mechanism in colorectal cancer (CRC). We aimed to exploit whether and how tumor-intrinsic m6A modification driven by methyltransferase like 3 (METTL3) can dictate the immune landscape of CRC. METHODS Mettl3 knockout mice,CD34+ humanized mice,and different syngeneic mice models were used. Immune cell composition and cytokine level were analyzed by flow cytometry and Cytokine 23-Plex immunoassay,respectively. M6A sequencing and RNA sequencing were performed to identify downstream targets and pathways of METTL3. Human CRC specimens (n = 176) were used to evaluate correlation between METTL3 expression and myeloid-derived suppressor cell (MDSC) infiltration. RESULTS We demonstrated that silencing of METTL3 in CRC cells reduced MDSC accumulation to sustain activation and proliferation of CD4+ and CD8+ T cells,and eventually suppressed CRC in ApcMin/+Mettl3+/- mice,CD34+ humanized mice,and syngeneic mice models. Mechanistically,METTL3 activated the m6A-BHLHE41-CXCL1 axis by analysis of m6A sequencing,RNA sequencing,and cytokine arrays. METTL3 promoted BHLHE41 expression in an m6A-dependent manner,which subsequently induced CXCL1 transcription to enhance MDSC migration in vitro. However,the effect was negligible on BHLHE41 depletion,CXCL1 protein or CXCR2 inhibitor SB265610 administration,inferring that METTL3 promotes MDSC migration via BHLHE41-CXCL1/CXCR2. Consistently,depletion of MDSCs by anti-Gr1 antibody or SB265610 blocked the tumor-promoting effect of METTL3 in vivo. Importantly,targeting METTL3 by METTL3-single guide RNA or specific inhibitor potentiated the effect of anti-programmed cell death protein 1 (anti-PD1) treatment. CONCLUSIONS Our study identifies METTL3 as a potential therapeutic target for CRC immunotherapy whose inhibition reverses immune suppression through the m6A-BHLHE41-CXCL1 axis. METTL3 inhibition plus anti-PD1 treatment shows promising antitumor efficacy against CRC. View Publication

BACKGROUND Acute respiratory distress syndrome (ARDS) is a neutrophil-associated disease. Delayed neutrophil apoptosis and increased levels of neutrophil extracellular traps (NETs) have been described in ARDS. We aimed to investigate the relationship between these phenomena and their potential as inflammation drivers. We hypothesized that delayed neutrophil apoptosis might enhance NET formation in ARDS. METHOD Our research was carried out in three aspects: clinical research,animal experiments,and in vitro experiments. First,we compared the difference between neutrophil apoptosis and NET levels in healthy controls and patients with ARDS and analyzed the correlation between neutrophil apoptosis and NET levels in ARDS. Then,we conducted animal experiments to verify the effect of neutrophil apoptosis on NET formation in Lipopolysaccharide-induced acute lung injury (LPS-ALI) mice. Furthermore,this study explored the relationship between neutrophil apoptosis and NETs at the cellular level. Apoptosis was assessed using morphological analysis,flow cytometry,and western blotting. NET formation was determined using immunofluorescence,PicoGreen assay,SYTOX Green staining,and western blotting. RESULTS ARDS neutrophils lived longer because of delayed apoptosis,and the cyclin-dependent kinase inhibitor,AT7519,reversed this phenomenon both in ARDS neutrophils and neutrophils in bronchoalveolar lavage fluid (BALF) of LPS-ALI mice. Neutrophils in a medium containing pro-survival factors (LPS or GM-CSF) form more NETs,which can also be reversed by AT7519. Tissue damage can be reduced by promoting neutrophil apoptosis. CONCLUSIONS Neutrophils with extended lifespan in ARDS usually enhance NET formation,which aggravates inflammation. Enhancing neutrophil apoptosis in ARDS can reduce the formation of NETs,inhibit inflammation,and consequently alleviate ARDS. View Publication

OBJECTIVE To identify immune cells,cytokines,and immune cell transcriptome in the menstrual effluent (ME) of women with endometriosis compared with that of healthy donors. DESIGN Live immune cells were isolated from human ME samples and were analyzed by flow cytometry to identify various immune cell populations. Selected cytokines from the same patients were evaluated using multiplex cytokine analyses. The transcriptome of the immune cell population was subsequently profiled using NanoString nCounter's PanCancer Immune panel. SETTING Academic institution. PATIENT(S) Surgically confirmed endometriosis patients (n = 14) and healthy fertile donors (n = 19). INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) In-depth immune cell profiling of ME obtained from women with endometriosis compared with that of healthy donors. RESULT(S) ME analysis revealed that the number of T helper 17 (TH17) cells was significantly lower in patients with endometriosis compared with that of healthy donors; the number of macrophages was also lower (P=.06) in the former. Multiplex cytokine analysis revealed significantly lower transforming growth factor $\alpha$ in the ME serum" of patients with endometriosis. Transcriptomic analysis of CD45+ cells revealed 47 differentially expressed genes mainly associated with the TH17 axis (IL10 IL23A and IL6) as well as genes associated with macrophage signaling/activation (CD74 CD83 CXCL16 and CCL3). CONCLUSION(S) We demonstrate for the first time that the levels of TH17 axis macrophages and transforming growth factor $\alpha$ were altered in the ME of women with endometriosis compared with that of healthy donors. These findings shed light on the potential immune pathways that could partly explain the pathogenesis and progression of endometriosis. Future large-scale studies on ME samples are warranted to exploit the use of these markers to study the pathogenesis of endometriosis." View Publication