Activation Of Adaptive Immune Cells Research Articles

Abstract A017: The FES tyrosine kinase as an emerging target for cancer immunotherapy

Abstract Immunotherapies are a promising emerging pillar of cancer treatment, but they still face many barriers due to the immunosuppressive nature of cancer. Cancer immunotherapy relies on the interplay between innate and adaptive immune responses. One way of stimulating such responses, known as immunogenic cell death (ICD), involves the release of tumour-associated antigens and damage associated molecular patterns (DAMPs). These DAMPs function to recruit and activate innate immune cells, including antigen-presenting cells (APCs), through engagement of pattern recognition receptors (PRRs), subsequently leading to production of the pro-inflammatory Signal 3 cytokines required for activation of adaptive immune cells (e.g., cytotoxic T lymphocytes [CTLs] and natural killer [NK] cells). The tyrosine kinase Fes suppresses innate immune responses in APCs by inhibiting components of the PRR signaling cascade. In non-cancer contexts, the negative regulation of APCs by Fes may guard against consequences of overactive innate immunity, including endotoxic shock or autoimmune disease. However, this same inhibitory effect on APC function may also serve as a checkpoint to successful anti-cancer immunotherapy, by obstructing efficient priming of cancer specific CTLs by APCs. Therefore, by inhibiting Fes, we hypothesize there will be greater Signal 3 cytokine production, resulting in greater CTL activation, and therefore improved tumor control. Using bone marrow derived APCs, including macrophages (BMDMs) and dendritic cells (BMDCs), from wildtype (WT) or Fes knockout (fes-/-) mice, we have shown through both Western blotting and flow cytometry analysis, that PRR signal transduction cascades are suppressed by Fes and increase levels of Signal 3 cytokines produced by fes-/- APCs. This includes higher levels of cell associated IL-12 in fes-/- APCs. Using syngeneic orthotopic mouse engraftment models of triple negative breast cancer (EO771) and melanoma (B16-F10) we showed that treatment with doxorubicin (which induces ICD) or anti-PD-1 (immune checkpoint inhibitor) plus doxorubicin controls tumor growth and prolongs survival to a greater extent in fes-/- mice. Immunophenotyping of tumors and spleens from these mice showed higher levels of activated CTLs and skewing of macrophages to a M1 state in fes-/- mice. SIINFEKL peptide loaded-BMDM/BMDCs from fes-/- mice were also more effective at priming CTLs from OT-1 mice (which express a T cell receptor that recognizes the SIINFEKL peptide) in antigen cross-presentation co-culture assays. These results implicate Fes as a potential novel immune checkpoint whose inhibition may enhance anti-cancer immunotherapy by suppressing its role in dampening inflammatory Signal 3 cytokine production by APCs. I will present recent data exploring the role of Fes in regulating the expression and trafficking of IL-12 in APCs to better understand the molecular basis of improved CTL activation by fes-/- APCs. Citation Format: Julian Simonetti, Brian J. Laight, Natasha Dmytryk, Danielle Harper, Yan Gao, Changnian Shi, Madhuri Koti, Sameh Basta, Peter A. Greer. The FES tyrosine kinase as an emerging target for cancer immunotherapy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Optimizing Therapeutic Efficacy and Tolerability through Cancer Chemistry; 2024 Dec 9-11; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(12_Suppl):Abstract nr A017.

Targeted interferon therapy with modakafusp alfa for relapsed or refractory multiple myeloma.

Interferon-alpha has activity against multiple myeloma. Modakafusp alfa is an immunocytokine comprising two attenuated interferon-alpha2b molecules and an anti-CD38 IgG4 antibody, targeting delivery of interferon-alpha to CD38+ immune and myeloma cells. This phase I/II trial (NCT03215030) enrolled patients with relapsed/refractory multiple myeloma with ≥3 prior lines of treatment and refractory to or intolerant of ≥1 proteasome inhibitor and ≥1 immunomodulatory drug. During dose escalation, modakafusp alfa was administered at ten doses in four schedules across 13 cohorts. The primary endpoint was safety for dose escalation, and overall response rate for dose expansion. We enrolled 106 patients who had received a median of 6.5 lines of prior therapy; 84% of patients had myeloma previously refractory to an anti-CD38 antibody. The most feasible dosing schedule was every 4 weeks (Q4W), at which the maximum tolerated dose was 3 mg/kg. Among 30 patients treated at 1.5 mg/kg Q4W, the overall response rate was 43.3%, with a median duration of response of 15.1 months (95% CI, 7.1-26.1); median progression-free survival was 5.7 months (95% CI, 1.2-14.0). Grade ≥3 adverse events occurred in 28 (93.3%) patients, the most common were neutropenia (66.7%) and thrombocytopenia (46.7%); infections were reported in 8 (26.7%) patients (including grade 3 in 4 [16.7%]). Modakafusp alfa therapy induced upregulation of the type I interferon gene signature score, increased CD38 receptor density in CD38+ cells, and innate and adaptive immune cell activation. Modakafusp alfa resulted in anti-tumor activity and immune activation in patients with multiple myeloma. Adverse events were primarily hematologic.

Unveiling the enigmatic roles of basophils in HIV infection: A narrative review.

The intricate interplay between the human immunodeficiency virus (HIV) and the immune system has long been a focal point in understanding disease progression. Among the myriad of immune cells, basophils, often overshadowed, have recently emerged as pivotal contributors to the complex immunological landscape of HIV infection. This paper aims to provide a succinct overview of the enigmatic roles of basophils in HIV pathogenesis, elucidating their multifaceted functions and implications. Basophils, conventionally perceived as minor players in immune responses, exhibit active participation in HIV infection. Their activation triggered by viral antigens, cytokines, and immune complexes orchestrates a cascade of immune events, influencing immune modulation, cytokine release, and the activation of adaptive immune cells. Furthermore, basophils function as antigen-presenting cells, potentially impacting viral dissemination and immune dysregulation. Additionally, basophils serve as crucial regulators in HIV infection through cytokine secretion, notably interleukin (IL)-4, IL-13, and IL-3, influencing immune cell differentiation, polarization, and antibody production. Their interactions with various immune cells intricately shape the immune response against HIV, impacting disease progression and immune equilibrium. Moreover, harnessing basophils as potential vaccine targets or immune modulators represents a compelling avenue for future research. In conclusion, the emerging understanding of basophils' multifaceted involvement in HIV infection challenges prior perceptions and underscores their significance in shaping immune responses and disease outcomes. This abstraction highlights the need for continued research to unlock the full potential of basophils, paving the way for novel strategies in combatting HIV/AIDS.

Safety and tolerability of tegoprubart in patients with amyotrophic lateral sclerosis: A Phase 2A clinical trial.

The interaction of CD40L and its receptor CD40 on activated T cells and B cells respectively control pro-inflammatory activation in the pathophysiology of autoimmunity and transplant rejection. Previous studies have implicated signaling pathways involving CD40L (interchangeably referred to as CD154), as well as adaptive and innate immune cell activation, in the induction of neuroinflammation in neurodegenerative diseases. This study aimed to assess the safety, tolerability, and impact on pro-inflammatory biomarker profiles of an anti CD40L antibody, tegoprubart, in individuals with amyotrophic lateral sclerosis (ALS). In this multicenter dose-escalating open-label Phase 2A study, 54 participants with a diagnosis of ALS received 6 infusions of tegoprubart administered intravenously every 2 weeks. The study was comprised of 4 dose cohorts: 1 mg/kg, 2 mg/kg, 4 mg/kg, and 8 mg/kg. The primary endpoint of the study was safety and tolerability. Exploratory endpoints assessed the pharmacokinetics of tegoprubart as well as anti-drug antibody (ADA) responses, changes in disease progression utilizing the Revised ALS Functional Rating Scale (ALSFRS-R), CD154 target engagement, changes in pro-inflammatory biomarkers, and neurofilament light chain (NFL). Seventy subjects were screened, and 54 subjects were enrolled in the study. Forty-nine of 54 subjects completed the study (90.7%) receiving all 6 infusions of tegoprubart and completing their final follow-up visit. The most common treatment emergent adverse events (TEAEs) overall (>10%) were fatigue (25.9%), falls (22.2%), headaches (20.4%), and muscle spasms (11.1%). Mean tegoprubart plasma concentrations increased proportionally with increasing dose with a half-life of approximately 24 days. ADA titers were low and circulating levels of tegoprubart were as predicted for all cohorts. Tegoprubart demonstrated dose dependent target engagement associated and a reduction in 18 pro-inflammatory biomarkers in circulation. Tegoprubart appeared to be safe and well tolerated in adults with ALS demonstrating dose-dependent reduction in pro-inflammatory chemokines and cytokines associated with ALS. These results warrant further clinical studies with sufficient power and duration to assess clinical outcomes as a potential treatment for adults with ALS. Clintrials.gov ID:NCT04322149.

Suppression of the JAK/STAT pathway inhibits neuroinflammation in the line 61-PFF mouse model of Parkinson’s disease

Parkinson’s disease (PD) is characterized by neuroinflammation, progressive loss of dopaminergic neurons, and accumulation of α-synuclein (α-Syn) into insoluble aggregates called Lewy pathology. The Line 61 α-Syn mouse is an established preclinical model of PD; Thy-1 is used to promote human α-Syn expression, and features of sporadic PD develop at 9–18 months of age. To accelerate the PD phenotypes, we injected sonicated human α-Syn preformed fibrils (PFFs) into the striatum, which produced phospho-Syn (p-α-Syn) inclusions in the substantia nigra pars compacta and significantly increased MHC Class II-positive immune cells. Additionally, there was enhanced infiltration and activation of innate and adaptive immune cells in the midbrain. We then used this new model, Line 61-PFF, to investigate the effect of inhibiting the JAK/STAT signaling pathway, which is critical for regulation of innate and adaptive immune responses. After administration of the JAK1/2 inhibitor AZD1480, immunofluorescence staining showed a significant decrease in p-α-Syn inclusions and MHC Class II expression. Flow cytometry showed reduced infiltration of CD4+ T-cells, CD8+ T-cells, CD19+ B-cells, dendritic cells, macrophages, and endogenous microglia into the midbrain. Importantly, single-cell RNA-Sequencing analysis of CD45+ cells from the midbrain identified 9 microglia clusters, 5 monocyte/macrophage (MM) clusters, and 5 T-cell (T) clusters, in which potentially pathogenic MM4 and T3 clusters were associated with neuroinflammatory responses in Line 61-PFF mice. AZD1480 treatment reduced cell numbers and cluster-specific expression of the antigen-presentation genes H2-Eb1, H2-Aa, H2-Ab1, and Cd74 in the MM4 cluster and proinflammatory genes such as Tnf, Il1b, C1qa, and C1qc in the T3 cluster. Together, these results indicate that inhibiting the JAK/STAT pathway suppresses the activation and infiltration of innate and adaptive cells, reducing neuroinflammation in the Line 61-PFF mouse model.

A β-1,3/1,6-glucan enhances anti-tumor effects of PD1 antibody by reprogramming tumor microenvironment

Checkpoint blockades have emerged as a frontline approach in cancer management, designed to enhance the adaptive immune response against tumors. However, its clinical efficacy is limited to a narrow range of tumor types, which necessitates the exploration of novel strategies that target another main branch of the immune system. One such potential strategy is the therapeutic modulation of pattern recognition receptors (PRRs) pathways in innate immune cells, which have shown promise in tumor eradication. Previously, a β-1,3/1,6-glucan with high purity from Durvillaea antarctica (BG136) was reported by our group to exhibit pan-antitumor effects. In the current study, we systemically studied the antitumor activity of BG136 in combination with anti-PD1 antibody in MC38 syngeneic tumor model in vivo. Integrated transcriptomic and metabolomic analyses suggested that BG136 enhanced the antitumor immunity of anti-PD1 antibody by reprogramming the tumor microenvironment to become more proinflammatory. In addition, an increase in innate and adaptive immune cell infiltration and activation, enhanced lipid metabolism, and a decrease in ascorbate and aldarate metabolism were also found. These findings provide mechanistic insights that support the potent antitumor efficacy of BG136 when combined with immune checkpoint inhibitor antibodies.

Abstract Mo015: Myeloid Specific PD-L1 Deletion Promotes Cardiac Dysfunction And Myocardial Inflammation

Background: Immunotherapy, particularly PD-1/PD-L1 blockers, is effective in cancer treatment but can cause rare, but potentially fatal heart issues. Despite the significant impact of these adverse events, there is limited research into the underlying mechanisms of immune checkpoint inhibitor (ICI)-mediated cardiotoxicity. PD-L1, which is abundantly expressed in cardiac tissue, particularly exhibits high expression levels over myeloid cells. However, the precise role of myeloid-specific PD-L1 signaling in mediating autoimmune cardiac disease pathology remains unclear. Methods and Results: To study the role of myeloid cell-specific PD-L1 (myeloid-PD-L1) in cardiac pathophysiology, we generated myeloid-specific PD-L1 KO mice, using Lyz2tm1(Cre) Ifo systems. As expected, PD-L1 expression was significantly down-regulated in Mφs from myeloid-PD-L1 KOs. The cardiac function was followed by echocardiography. Controls and myeloid-PD-L1-KO hearts had comparable ventricular function at 1 month of age. Interestingly, as early as 2 months of age, myeloid-PD-L1-KOs displayed marked cardiac dysfunction as reflected by reduced LVEF, LVFS, and HF markers. Immune profiling was conducted whether chronic inflammation contributes to cardiac dysfunction and remodeling at a later age as observed at 2 and 3 months of age. Interestingly, excessive systemic inflammation and substantial immune infiltration (innate and adoptive), activation, and a pro-inflammatory cytokine storm were detected in the KO hearts. Furthermore, myeloid-PD-L1 KO hearts showed increased recruitment of pro-inflammatory CCR2+ monocytes and macrophages. Conclusion: Our data with myeloid-PD-L1 KOs suggest that deleting PD-L1 in myeloid lineage promotes myocardial and systemic inflammation through innate and adaptive immune cell activation and recruitment of CCR2+ MΦs. Subsequently, this leads to impaired cardiac pathophysiology. Thus, these translational studies will directly evaluate the potential of targeting myeloid-PD-L1 signaling to alleviate cardiac damage.

Gut bacteria, host immunity, and colorectal cancer: From pathogenesis to therapy.

The emergence of 16S rRNA and metagenomic sequencing has gradually revealed the close relationship between dysbiosis and colorectal cancer (CRC). Recent studies have confirmed that intestinal dysbiosis plays various roles in the occurrence, development, and therapeutic response of CRC. Perturbation of host immunity is one of the key mechanisms involved. The intestinal microbiota, or specific bacteria and their metabolites, can modulate the progression of CRC through pathogen recognition receptor signaling or via the recruitment, polarization, and activation of both innate and adaptive immune cells to reshape the protumor/antitumor microenvironment. Therefore, the administration of gut bacteria to enhance immune homeostasis represents a new strategy for the treatment of CRC. In this review, we cover recent studies that illuminate the role of gut bacteria in the progression and treatment of CRC through orchestrating the immune response, which potentially offers insights for subsequent transformative research.

A novel oral TLR7 agonist orchestrates immune response and synergizes with PD-L1 blockade via type I IFN pathway in lung cancer

Despite the groundbreaking impact of immune checkpoint blockade (ICB), response rates in non-small cell lung cancer remain modest, particularly in immune-excluded or immune-desert microenvironments. Toll-like receptor 7 (TLR7) emerges as a latent target bridging innate and adaptive immunity, offering a promising avenue for combination therapies to augment ICB efficacy. Here, we explored the anti-tumor activity of the novel oral TLR7 agonist TQ-A3334 and its potential to enhance anti-programmed death ligand 1 (PD-L1) therapy through a combination strategy in a syngeneic murine lung cancer model. Oral administration of TQ-A3334 significantly alleviated tumor burden in C57BL/6J mice, modulated by type I interferon (IFN), and exhibited low toxicity. This therapy elicited activation of both innate and adaptive immune cells in tumor tissue, particularly increasing the abundance of CD8+ TILs through type I IFN pathway and subsequent CXCL10 expression. In vitro examinations validated that IFN-α-stimulated tumor cells exhibited increased secretion of CXCL10, conducive to the promoted trafficking of CD8+ T cells. Furthermore, combining TQ-A3334 with anti-PD-L1 treatment exceeded tumor control, with a further increase in CD8+ TIL frequency compared to monotherapy. These findings suggest that TQ-A3334 can mobilize innate immunity and promote T cell recruitment into the tumor microenvironment; a combination of TQ-A3334 and anti-PD-L1 antibodies can intensify the sensitivity of tumors to anti-PD-L1 therapy, which demonstrates significant potential for treating poorly immune-infiltrated lung cancer.

Natural killer-like B cells are a distinct but infrequent innate immune cell subset modulated by SIV infection of rhesus macaques.

Natural killer-like B (NKB) cells are unique innate immune cells expressing both natural killer (NK) and B cell receptors. As first responders to infection, they secrete IL-18 to induce a critical cascade of innate and adaptive immune cell infiltration and activation. However, limited research exists on the role of NKB cells in homeostasis and infection, largely due to incomplete and erroneous evaluations. To fill this knowledge gap, we investigated the expression of signaling and trafficking proteins, and the in situ localization and transcriptome of naïve NKB cells compared to conventionally-defined NK and B cells, as well as modulations of these cells in SIV infection. Intracellular signaling proteins and trafficking markers were expressed differentially on naïve NKB cells, with high expression of CD62L and Syk, and low expression of CD69, α4β7, FcRg, Zap70, and CD3z, findings which were more similar to B cells than NK cells. CD20+NKG2a/c+ NKB cells were identified in spleen, mesenteric lymph nodes (MLN), colon, jejunum, and liver of naïve rhesus macaques (RM) via tissue imaging, with NKB cell counts concentrated in spleen and MLN. For the first time, single cell RNA sequencing (scRNAseq), including B cell receptor (BCR) sequencing, of sorted NKB cells confirmed that NKB cells are unique. Transcriptomic analysis of naïve splenic NKB cells by scRNAseq showed that NKB cells undergo somatic hypermutation and express Ig receptors, similar to B cells. While only 15% of sorted NKB cells showed transcript expression of both KLRC1 (NKG2A) and MS4A1 (CD20) genes, only 5% of cells expressed KLRC1, MS4A1, and IgH/IgL transcripts. We observed expanded NKB frequencies in RM gut and buccal mucosa as early as 14 and 35 days post-SIV infection, respectively. Further, mucosal and peripheral NKB cells were associated with colorectal cytokine milieu and oral microbiome changes, respectively. Our studies indicate that NKB cells gated on CD3-CD14-CD20+NKG2A/C+ cells were inclusive of transcriptomically conventional B and NK cells in addition to true NKB cells, confounding accurate phenotyping and frequency recordings that could only be resolved using genomic techniques. Although NKB cells were clearly elevated during SIV infection and associated with inflammatory changes during infection, further interrogation is necessary to acurately identify the true phenotype and significance of NKB cells in infection and inflammation.

Abstract CT078: Phase 1 study of SGN-EGFRd2 in solid tumors (SGNEGFRd2-001)

Abstract Background: Epidermal growth factor receptor (EGFR) is a cell surface receptor expressed in a variety of solid tumors. Gamma delta (γδ)-T cells represent a conserved T cell subset that can induce cell death in a wide range of malignancies. The presence of γ9δ2-T cells in solid tumors strongly correlates with better patient survival (Gentles 2015; Tosolini 2017). In addition to direct, potent killing by release of cytotoxic molecules, activated γ9δ2-T cells process and present antigen and contribute to a cascade response resulting in downstream activation of innate and adaptive immune cells to mediate further tumor cell killing (Brandes 2005; Devilder 2006; Vantourout 2013). Novel approaches that improve targeting and activation of γ9δ2-T cells may lead to the development of effective and safe cancer treatments. SGN-EGFRd2 is an investigational, bispecific humanized heavy chain-only antibody (HcAb). Advantages of HcAbs include their small size, high solubility, high stability, and excellent tissue penetration in vivo (Bannas 2017). SGN-EGFRd2 simultaneously binds EGFR and the γ9δ2-T cell receptor, resulting in the conditional activation of γ9δ2-T cells. Importantly, full activation of γ9δ2-T cells requires a secondary phosphoantigen stress signal present only in malignant and certain infected cells (Deseke 2020; Herrmann 2020; Rigau 2020; Vantourout 2013), but not normal healthy cells, conferring preferential tumor-directed cytotoxicity. The proposed cytotoxic mechanism of action is independent of KRAS and BRAF mutations (King 2023) known to confer resistance to approved anti-EGFR therapies in colorectal cancer (CRC). This first-in-human study is evaluating the safety, tolerability, and antitumor activity of SGN-EGFRd2 in patients with advanced solid tumors. Methods: SGNEGFRd2-001 (NCT05983133) is an open-label, multicenter, phase 1, dose escalation and expansion study evaluating SGN-EGFRd2 monotherapy in patients with relapsed/refractory (R/R) CRC, head and neck squamous cell cancer, non-small cell lung cancer, and pancreatic ductal adenocarcinoma in 3 parts: dose escalation (Part A; n ~ 75), dose optimization (Part B; optional; up to n = 40), and dose expansion (Part C; up to n = 160). Patients must have R/R disease, or be intolerant to standard of care therapies, with no appropriate standard therapy available. Patients must have measurable disease per RECIST v1.1, an ECOG performance status of 0 or 1, and adequate organ function. Patients are eligible regardless of tumor EGFR expression or EGFR/KRAS/BRAF mutation status. Patients will receive SGN-EGFRd2 as an intravenous infusion. Primary study objectives are safety and tolerability, maximum tolerated dose, and recommended dose and schedule. Secondary objectives include pharmacokinetics, immunogenicity, and antitumor activity. Tumor samples will be analyzed for exploratory biomarkers. Accrual is ongoing in the US. Additional sites in Europe and Canada are planned. Citation Format: Hirva Mamdani, Joel Randolph Hecht, Rachel E. Sanborn, Maria Corinna Palanca-Wessels, Mingjin Yan, Martin Gutierrez, David L. Bajor. Phase 1 study of SGN-EGFRd2 in solid tumors (SGNEGFRd2-001) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT078.

Abstract 1183: A first-in-class and SHP1 allosteric inhibitor, SB8091, shows a good efficacy and safety profile in preclinical models

Abstract Introduction: Src homology 2 domain-containing phosphatase 1 (SHP1) is a cytoplasmic protein tyrosine phosphatase (PTP) that is primarily expressed in hematopoietic cells and is commonly recognized as a negative regulator of multiple signaling pathways1. Previously, we showed that inhibition of the phosphatase activity of SHP1 by a novel SHP1 allosteric inhibitor, SB6299, results in the activation of innate and adaptive immune cells and enhanced anti-tumor immune responses2. Here, we report SB8091, an advanced SHP1 allosteric inhibitor with a promising initial safety profile and improved pharmacokinetic properties. Methods: SHP1 inhibitors were developed through a structure-based drug design approach, and optimized for cellular activity on target, in vitro ADME, and in vivo pharmacokinetic properties. Pharmacokinetic (PK) and preliminary toxicity studies were performed with mice. The lead series was assessed in in-vitro studies with mouse or human primary immune cells. In-vivo efficacy and pharmacodynamic data were generated using mouse syngeneic tumor models. Results: Structurally, SB8091 seemed to stabilize the autoinhibitory form of SHP1 as an allosteric inhibitor, in a nanomolar range and which can explain the outstanding selectivity compared to other PTP enzymes, including SHP2. In several human primary immune cell types, SB8091 significantly increased cytokine responses and demonstrated significantly enhanced activity in NK cells and macrophages against various cancer target cells. As a single agent, this compound exhibited inhibitory effects on tumor growth when administered orally, and the efficacy was further enhanced when co-administered with anti-PD1 antibodies in various syngeneic tumor models. Notably, this effect was associated with a pharmacodynamic response marked by increased levels of phosphorylated substrates regulated by SHP1. SB8091 exhibited favorable pharmacokinetic properties for oral administration, and SafetyScreen data showed a very low potential for off-target activity and drug-drug interactions. Additionally, during a 2-week repeat pilot toxicity study in mice, SB8091 demonstrated excellent tolerability even at high doses, indicating a high therapeutic index (TI > 100). Conclusion: Our advanced compound, SB8091, is a potent, highly selective, and orally bioavailable allosteric inhibitor of SHP1. It has demonstrated excellent efficacy as a monotherapy or in combination with immune checkpoint blockers, with favorable drug properties and safety profiles. Research to advance to the clinical stage is being conducted.

Gene-edited pigs: a translational model for human food allergy against alpha-Gal and anaphylaxis.

The prevalence of food allergy is rising and is estimated to approach 10%. Red meat allergy is the first known food allergy elicited by immunoglobulin E (IgE) antibodies recognizing a carbohydrate. Due to the loss of function of the alpha-1,3-galactosyltransferase (GGTA1) gene in humans, the disaccharide galactose-α-1,3-galactose (α-Gal) cannot be synthesized and therefore became immunogenic. IgE sensitization is elicited through the skin by repetitive tick bites transmitting α-Gal. The underlying mechanisms regarding innate and adaptive immune cell activation, including the B-cell isotype switch to IgE, are poorly understood, requiring further research and physiologically relevant animal models. Here, we describe a new animal model of red meat allergy using percutaneous α-Gal sensitization of gene-edited GGTA1-deficient pigs. Total and α-Gal-specific IgG, IgG1, IgG2, IgG4, and IgE levels were tracked. Further key factors associated with allergic skin inflammation, type 2 immunity, and allergy development were measured in PBMCs and skin samples. Significant increases in α-Gal-specific IgG1 and IgE levels indicated successful sensitization to the allergen α-Gal. Intracutaneous sensitizations with α-Gal recruited lymphocytes to the skin, including elevated numbers of T helper 2 (Th2) cells. Finally, α-Gal-sensitized pigs not only recognized α-Gal as non-self-antigen following α-Gal exposure through the skin but also developed anaphylaxis upon antigen challenge. Based on the similarities between the porcine and human skin, this new large animal model for α-Gal allergy should help to unveil the consecutive steps of cutaneous sensitization and aid the development of prophylactic and treatment interventions.

Lipid peroxidation of immune cells in cancer.

Growing evidence indicates that cellular metabolism is a critical determinant of immune cell viability and function in antitumor immunity and lipid metabolism is important for immune cell activation and adaptation to the tumor microenvironment (TME). Lipid peroxidation is a process in which oxidants attack lipid-containing carbon-carbon double bonds and is an important part of lipid metabolism. In the past decades, studies have shown that lipid peroxidation participates in signal transduction to control cell proliferation, differentiation, and cell death, which is essential for cell function execution and human health. More importantly, recent studies have shown that lipid peroxidation affects immune cell function to modulate tumor immunity and antitumor ability. In this review, we briefly overview the effect of lipid peroxidation on the adaptive and innate immune cell activation and function in TME and discuss the effectiveness and sensitivity of the antitumor ability of immune cells by regulating lipid peroxidation.

A Bidirectional Immunological Relationship between Diabetes Mellitus and Tuberculosis: A Narrative Review

Tuberculosis (TB) is one of the most common contagious diseases worldwide. Over the past few decades, researchers have made significant efforts to prevent TB. Recent predictions indicate that the prevalence of Diabetes Mellitus (DM) will reach 552 million by 2023 due to ongoing epidemiological changes in several countries across the globe. India is expected to have 62-80 million people with diabetes by 2030, making it the "Diabetes Capital" of the world. Present review discusses the urgent need to understand the mechanisms and implications of DM on the immune systems of TB patients. The correlation between TB and DM has been shown to be bidirectional. Numerous studies have revealed a higher prevalence of diabetes in TB patients, as their immune systems are compromised. TB patients with DM experience progressive deficits in both innate and adaptive immune cell activity, reducing their ability to suppress Mycobacterium tuberculosis (M. tuberculosis) and increasing their risk of developing TB. Increased inflammation and elevated levels of inflammatory cytokines in circulation are characteristics of TB with DM co-morbidity, which indicate the active involvement of the angiogenesis-inflammation nexus. Therefore, to alleviate the burden of both disorders, it would be beneficial to make informed therapy choices by gaining a better understanding of TB immunology in the context of DM.

Based on Weighted Gene Co-Expression Network Analysis Reveals the Hub Immune Infiltration-Related Genes Associated with Ulcerative Colitis.

Immune infiltration plays a pivotal role in the pathogenesis of mucosal damage in ulcerative colitis (UC). The objective of this study was to systematically analyze and identify genetic characteristics associated with immune infiltration in UC. Gene expression data from three independent datasets obtained from the Gene Expression Omnibus (GEO) were utilized. By employing the ssGSEA and CIBERSORT algorithms, we estimated the extent of immune cell infiltration in UC samples. Subsequently, Weighted Correlation Network Analysis (WGCNA) was performed to identify gene modules exhibiting significant associations with immune infiltration, and further identification of hub genes associated with immune infiltration was accomplished using least absolute shrinkage and selection operator (LASSO) regression analysis. The relationship between the identified hub genes and clinical information was subsequently investigated. Our findings revealed significant activation of both innate and adaptive immune cells in UC. Notably, the expression levels of CD44, IL1B, LYN, and ITGA5 displayed strong correlations with immune cell infiltration within the mucosa of UC patients. Immunohistochemical analysis confirmed the significant upregulation of CD44, LYN, and ITGA5 in UC samples, and their expression levels were found to be significantly associated with common inflammatory markers, including the systemic immune inflammation indices, C-reactive protein, and erythrocyte sedimentation rate. CD44, LYN, and ITGA5 are involved in the immune infiltration pathogenesis of UC and may be potential therapeutic targets for UC.

Tumor-derived extracellular vesicles in the immune microenvironment of head and neck squamous cell carcinoma: Foe or future?

Head and neck squamous cell carcinoma (HNSCC) is considered a “cold tumor” due to its suppressive immune microenvironment, and is associated with a poor prognosis. Tumor-derived extracellular vesicles (EVs) play an essential role in the tumor microenvironment and mediate intercellular communications. EVs have been proven to be key immune regulators involved in antitumor immune responses and escape from immune surveillance. Tumor-derived EVs favor the formation of an immunosuppressive tumor microenvironment by regulating the differentiation, proliferation and activation of innate and adaptive immune effector cells, as well as myeloid cells, acting as a “foe” in the microenvironment. However, EVs are also valuable for predicting and improving the prognosis of HNSCC, and represent hope for future treatments. In this review, we summarize the impact of HNSCC-derived EVs on the immune microenvironment, describe their roles as biomarkers and for drug delivery in disease monitoring and treatment. We provide insights into important areas for future research and identify potential therapeutic targets for HNSCC treatment.

TMIC-59. IL-2 SECRETING ENGINEERED MYELOID CELLS POTENTIATE CYTOTOXIC EFFECTOR CELL ACTIVATION TO DELAY MALIGNANT PROGRESSION IN A PRECLINICAL MODEL OF GLIOMA

Abstract INTRODUCTION Gliomas are the most prevalent brain tumor in the adolescent and young adult population (AYA) and one of the leading causes of cancer-related death. In fact, two-thirds of glioma AYA patients are affected by low-grade gliomas (LGGs). Moreover, there are no therapies to prevent glioma LGG malignant progression. Malignant progression is associated with a significant reduction of tumor infiltrating cytotoxic effector immune cells, primarily due to the immunosuppressive tumor microenvironment (TME) mediated by regulatory T lymphocytes, tumor associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs). To that end, immunotherapies have had limited efficacy in improving outcomes for primary and secondary HGGs. HYPOTHESIS We hypothesize that engineered myeloid cells that release IL-2 will enhance the trafficking of activated effector T cells and potentiate a pro-inflammatory cascade in the low-grade glioma TME, delaying malignant progression. METHODS Immunocompetent RCAS n/tv-a LGG bearing animals were retro-orbitally treated at day 21 with a single dose of bone-marrow derived myeloid cells, engineered for the release of Interlekin-2 (GEMys-IL2). The inflammatory status of the TME along with the composition and functional status of tumor infiltrating immune cells were investigated in vivo by cytokine array, mass cytometry, and bulk RNA sequencing. RESULTS Our complementary dataset demonstrated that GEMys-IL2 infiltrated the glioma microenvironment and triggered a pro-inflammatory cascade involving the upregulation and release of IL2, IFNy, CXCL9, Tim1, CD26 and other pro-inflammatory cytokines associated with the activation and recruitment of innate and adaptive immune cells within the TME. In addition, we observed a downregulation of immunosuppressive signaling pathways such as IL10, PPAR, LXR/RXR, CTLA4 and PD-1. Also, a single dose of GEMys-IL2 systemically injected in RCAS/t-va immunocompetent LGG bearing mice potentiated pro-inflammatory remodeling of the TME and significantly improved overall survival. CONCLUSIONS These preclinical studies highlight a novel approach in developing next-generation innate immunotherapies.

Modakafusp Alfa Demonstrates Type I Interferon-Mediated Innate and Adaptive Immune Enhancement in a Phase 1/2 Study in Patients with Relapsed and/or Refractory Multiple Myeloma (RRMM)

Modakafusp alfa (moda), a novel immunocytokine, is an innate immunity enhancer comprising two attenuated interferon (IFN) α2b molecules fused to an anti-CD38 IgG4 monoclonal antibody backbone, driving preferential IFNα signalling in CD38-expressing innate and adaptive immune cells as well as myeloma cells. Here, we present pharmacodynamic (PD) data from the first-in-human Phase 1/2 study of moda as a monotherapy in patients with RRMM (iinnovate-1; NCT03215030). A total of 37 patients treated with moda at 1.5 or 3 mg/kg every 4 weeks were included in the analysis. Peripheral blood (PB) and bone marrow (BM) samples were collected during screening or pre-dose on cycle 1 day 1 (C1D1) and at multiple timepoints after treatment. BM and PB samples were evaluated by cytometry time of flight (CyTOF) and bulk RNA sequencing (RNAseq) to assess pharmacodynamic changes in immune cell populations, cell activation, and gene expression. Administration of moda led to enhanced innate immune cell activation and cytotoxic function as demonstrated by increased proportions of CD69+ and granzyme B+ in peripheral NK cells analyzed by CyTOF. This was accompanied by a decrease in the proportion of TIGIT+ NK cells, indicating reduced inhibitory signaling. Furthermore, enhanced proliferation (%Ki67+) of NK cells was observed in both BM and PB. Moda also impacted myeloid cell populations in BM and PB. Dendritic cells (DCs) and monocytes in PB showed increased surface expression of the co-stimulatory molecule CD86, suggesting a potential for enhanced antigen presentation and co-stimulation ability. Increased proliferation (%Ki67) of DCs and monocytes was detected in both PB and BM, accompanied by a decrease in numbers of peripheral DCs which may indicate recruitment or homing to secondary lymphoid organs. Additionally, RNAseq analysis revealed that treatment with moda led to upregulation of CD68 expression in both PB and BM, indicating a proinflammatory M1 macrophage type response. Finally, CyTOF analysis also indicated that moda significantly impacted adaptive immunity. We observed enhanced activation (%CD69, %PD1 and %CD40L) and cytotoxic function (%granzyme B) of peripheral CD8 T cells, and increased CD8 T cell proliferation (%Ki67 CD8) in both PB and BM samples. Enhanced activation of peripheral CD4 T cells (%CD69, %CD40L) was also detected. Consistent with activation of the adaptive immune system, there was a reduction in naïve CD8 T cells accompanied by an increase in CD8 T effector memory cells in PB. Analysis of exhaustion markers (TIGIT, PD-1) in cycle 1 (C1D8, C1D15, and C2D1 predose) showed that moda did not induce CD8 T cell exhaustion in either PB or BM, and there was no change in FoxP3+ Treg cells. Moda-induced innate and adaptive immune cell phenotypic changes were evaluated for correlation with clinical response at timepoints with sufficient number of evaluable samples. While none of the associations were statistically significant after correcting for multiplicity testing (using the false discovery rate method), we observed trends warranting further investigation. There was a greater increase of CD40L+ NK cells and PD1+ CD8 cells in responders vs. non-responders at C1D2. Additionally, at C1D15 responders showed a lower increase in proliferation (%Ki67+) of classical monocytes, NK cells, and myeloid DCs in PBas compared to non-responders. A similar trend was also observed in the BM classical monocytes. Even though the peak of Ki67 expression was observed at C1D8, diminished increases of proliferating cells at C1D15 in responders was a surprising observation that needs further consideration. The PD biomarker data from this first-in-human clinical trial demonstrated that treatment with moda enhances both innate and adaptive immune cell activation in PB and BM. Importantly, moda-mediated immune activation did not result in T cell exhaustion during cycle 1, as evaluated in both PB and BM. We have observed interesting trends of immune phenotypic changes that may correlate with response. Follow-up analyses of the correlation of biomarkers with clinical response are in progress and will be presented. Further clinical trials are underway (iinnovate-2, NCT05556616; iinnovate-3, NCT05590377) to evaluate moda's novel immune activating mechanism in combination with standard of care anti-myeloma therapies.

Ferroptosis in the post-transplantation inflammatory response

Transplantation is a life-saving therapy for patients with end-stage organ disease. Successful outcomes after transplantation require mitigation of the post-transplant inflammatory response, limiting alloreactivity, and prevention of organ rejection. Traditional immunosuppressive regimens aim to dampen the adaptive immune response; however, recent studies have shown the feasibility and efficacy of targeting the innate immune response. Necroinflammation initiated by donor organ cell death is implicated as a critical mediator of primary graft dysfunction, acute rejection, and chronic rejection. Ferroptosis is a form of regulated cell death that triggers post-transplantation inflammation and drives the activation of both innate and adaptive immune cells. There is a growing acceptance of the clinical relevance of ferroptosis to solid organ transplantation. Modulating ferroptosis may be a potentially promising strategy to reduce complications after organ transplantation.