Mediated Immune Response Research Articles

Abstract PR005: Modulating the immunosuppressive pancreas tumor microenvironment through intratumoral delivery of cytokine-encoding mRNAs

Abstract Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive cancer, with a mere 13% average 5-year survival rate. The hallmark desmoplastic stromal response in PDAC leads to poor vascularization, drug delivery challenges, and impaired cytotoxic immune cell infiltration, contributing to de novo therapy resistance. Our previous research has shown therapeutic induction of cellular senescence with RAS pathway targeting therapies can induce cytokine and chemokine production through the senescence-associated secretory phenotype (SASP) that can effectively activate anti-tumor T cell immunity and responses to anti-PD-1 immune checkpoint blockade. To build on these findings as well as overcome limitations associated with senescence-inducing therapy toxicity and induction of pro-tumorigenic SASP cytokines, here we leveraged mRNA technology to deliver specific SASP cytokines and chemokines we have found to stimulate immune responses directly into the suppressive PDAC TME as an immune oncology platform. We created an in vitro transcription pipeline for mRNA production and multiplexing, and demonstrate we can intratumorally deliver multiple mRNAs simultaneously into the TME of transplanted and autochthonous PDAC mouse models, stimulating the local production of cytokines normally absent in PDAC. We further characterized a novel combination of five cytokines and chemokines that can effectively recruit and activate both innate and adaptive immune responses against PDAC. Through repeated bi-weekly dosing, this mRNA combination also promotes tumor destruction and improves survival outcomes. Considering the recent success of off-the-shelf neoantigen mRNA vaccines in early human PDAC patient trials, we have now developed mRNAs that encode PDAC-specific antigens. By integrating our cytokine mRNA platform with antigen mRNAs, we observe a significant increase in intratumoral antigen-presenting dendritic cell populations and a substantially enhanced T-cell mediated anti-tumor immune response in orthotopic transplant models of PDAC. Overall, this study not only unveils pivotal insights into the cytokines absent in PDAC that are crucial for promoting anti-tumor immunity, but also pioneers an innovative immunotherapy approach. This platform has the potential to be integrated with existing immunotherapy modalities, addressing the longstanding challenge of therapy resistance in PDAC. Citation Format: Chaitanya Naimesh Parikh, Kelly De Marco, Boyang Ma, Katherine Murphy, Loretah Chibaya, Lin Zhou, Youwei Qiao, Griffin Kane, Li Li, Wen Xue, Marcus Ruscetti. Modulating the immunosuppressive pancreas tumor microenvironment through intratumoral delivery of cytokine-encoding mRNAs [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr PR005.

Cow’s milk protein allergy in infants and children

Abstract Cow’s milk protein allergy (CMPA) is an immune-mediated reaction to cow’s milk proteins, which can involve multiple organ systems including the gastrointestinal tract. Immunoglobulin E (IgE)-mediated response results in rapid onset of allergic symptoms that are easily recognizable. However, delayed (i.e., non-IgE/cell-mediated) or mixed (IgE- and cell-mediated) reactions produce a host of symptoms that overlap with other conditions and vary widely in onset and severity. Determining whether symptoms represent immune-mediated CMPA, non-immunologic reaction to cow’s milk, or are unrelated to cow’s milk exposure is challenging yet essential for effective management. While the clinical presentation of non-IgE-mediated CMPA can vary, this condition is usually self-limited and resolves by 1 to 6 years of age. Food antigen-specific immunoglobulin G (IgG) panels that are not evidence-based should be avoided because they can lead to overdiagnosis of presumed food intolerances. Overdiagnosis of CMPA can result in overuse of extensively hydrolyzed formulas and have significant cost implications for families. This statement focuses on delayed non-IgE/cell-mediated CMPA and assists health care providers to distinguish between and identify varied reactions to cow’s milk, discusses the role of diagnostic testing, and provides management recommendations based on best evidence.

Retrospective analysis of the safety and efficacy of Pembroria® during non-medical switching from the original drug Keytruda® in patients with advanced malignancies of various localizations in real clinical practice

Introduction. The emergence of genetically engineered biological drugs is rightly considered a revolutionary event in medicine. In 2022, the first biosimilar of pembrolizumab, the Russian drug Pembroria®, was approved. One of the study types that can convincingly demonstrate the safety and efficacy of biosimilar is its use for switching from the original drug for non-medical indications (NMS, or non-medical switching) according to standard approaches of real clinical practice and the drug label. Aim. To assess the safety of NMS switching in patients with advanced malignancies of various localizations from the original drug Keytruda® to the biosimilar Pembroria® and to evaluate its effectiveness in real clinical practice. Materials and methods. We analyzed the data of 114 patients with advanced malignancies of various localizations and the last line of treatment with Keytruda® as monotherapy or in combination with other agents within the approved indications and switched to Pembroria® for NMS. After switching to Pemboria®, patients did not change treatment for another checkpoint inhibitor within this line of therapy. Results. The incidence of immune-mediated adverse reactions (imARs) of any severity during treatment with comparators differed slightly: 57% with Keytruda® and 54% with Pembroria®. The majority of imARs with both Keytruda® and Pembroria® were Grade 1 in severity (69% and 86%, respectively). All serious ARs were resolved and did not result in drug discontinuation. When analyzing the best objective response to treatment with Keytruda®, complete response, partial response, and stabilization were observed in 9 (7.9%), 28 (24.6%), and 61 (53.5%) cases, respectively, during treatment with Pemboria® – in 8 (7%), 24 (21%), 52 (45.6%) cases, respectively. Conclusion. The safety profile of Keytruda® and Pembroria® is acceptable and comparable: the imAR rate with Pembroria® when switching from Keytrada® did not exceed that with the original drug Keytruda®; in most patients, switching from Keytruda® to Pembroria® was not associated with an increase in the imAR rate or severity. The majority of patients maintained disease control when switched to Pembroria®.

Dietary assessments in individuals living with coeliac disease: key considerations.

Coeliac disease (CeD) is a type of enteropathy characterised by an immune-mediated reaction to ingested gluten, resulting in impaired absorption of nutrients and symptoms such as bloating, abdominal cramping and diarrhoea. Currently, the only treatment for CeD is adherence to a gluten-free diet (GFD). The latest draft guidance from the US Food and Drug Administration recommends that dietitians experienced in CeD management evaluate patients during the screening and treatment period of CeD clinical trials to assess adherence to a GFD. However, there are currently no standardised guidelines on dietary assessment of patients with CeD on a GFD and there is a lack of widespread availability of expertise in this field. Based on the findings of a literature review conducted between April and September 2023, this article provides an overview of key points to consider in the nutritional and dietary assessment of patients with CeD who are following a GFD, with particular focus on the clinical trial setting. Based on a consensus from dietitians and gastroenterologists experienced in treating patients with CeD, we present specific recommendations for registered dietitians who manage patients with CeD. We also describe the development of a simplified tool for assessment of adherence to a GFD, the Gluten-Free Adherence Survey, based on these recommendations. These guidelines cover nutritional and dietary assessment of patients with CeD, physical assessments, intake of oats, environmental considerations and the disease burden.

Exploring transcriptomic mechanisms underlying pulmonary adaptation to diverse environments in Indian rams.

The Changthangi sheep thrive at high altitudes in the cold desert regions of Ladakh, India while Muzaffarnagri sheep are well-suited to the low altitude plains of northern India. This study investigates the molecular mechanisms of pulmonary adaptation to diverse environments by analyzing gene expression profiles of lung tissues through RNA sequencing. Four biological replicates of lung tissue from each breed were utilized to generate the transcriptomic data. Differences in gene expression analysis revealed discrete expression profiles in lungs of each breed. In Changthangi sheep, genes related to immune responses, particularly cytokine signaling, were significantly enriched. Pathway analysis highlighted the activation of NF-kB signaling, a key mediator of inflammation and immune response. Additionally, the gene network analysis indicated a strong association between cytokine signaling, hypoxia-inducible factor (HIF) and NF-kB activation, suggesting a coordinated response to hypoxic stress in lungs of Changthangi sheep. In Muzaffarnagri sheep, the gene expression profiles were enriched for pathways related to energy metabolism, homeostasis and lung physiology. Key pathways identified include collagen formation and carbohydrate metabolism, both of which are crucial for maintaining lung function and structural integrity. Gene network analysis further reinforced this by revealing a strong connection between genes associated with lung structure and function. Our findings shed light on the valuable insights into gene expression mechanisms that enable these sheep breeds to adapt to their respective environments and contribute to a better understanding of high altitude adaptation in livestock.

Beyond the gut: Exploring neurological manifestations in inflammatory bowel disease

Neurological manifestations in inflammatory bowel diseases (IBD), such as Crohn’s disease and ulcerative colitis, are increasingly recognized as significant contributors to both disease burden and patient morbidity. This comprehensive review delves into the spectrum of neurological complications linked with IBD, highlighting the involvement of both the central and peripheral nervous systems. The neurological impairments range from more common conditions such as peripheral neuropathy, characterized by nerve damage leading to pain and numbness, and cerebrovascular diseases, which include strokes and transient ischemic attacks, to less frequent but intensely severe conditions such as multiple sclerosis and myasthenia gravis, which involve the immune system attacking components of the nervous system. The complex pathophysiology underlying these manifestations integrates various factors including immune-mediated responses, vascular abnormalities such as thromboembolism, nutritional deficiencies often exacerbated by malabsorption and chronic inflammation, and the adverse effects elicited by IBD medications such as corticosteroids and immunomodulators. This review underscores the importance of adopting a multidisciplinary management approach. By integrating the expertise of gastroenterologists with that of neurologists, rheumatologists, and other specialists, patient outcomes can be significantly optimized. Further emphasis is placed on the necessity for heightened clinical awareness and the implementation of early diagnostic interventions to effectively identify and mitigate the neurological complications associated with IBD. In conclusion, ongoing research aimed at elucidating the underlying mechanisms that connect IBD with neurological disorders is imperative to facilitate the development of more effective preventative and therapeutic strategies for these challenging complications.

Metabolic Reprogramming in Cancer: Implications for Immunosuppressive Microenvironment.

Cancer is a complex and heterogeneous disease characterised by uncontrolled cell growth and proliferation. One hallmark of cancer cells is their ability to undergo metabolic reprogramming, which allows them to sustain their rapid growth and survival. This metabolic reprogramming creates an immunosuppressive microenvironment that facilitates tumour progression and evasion of the immune system. In this article, we review the mechanisms underlying metabolic reprogramming in cancer cells and discuss how these metabolic alterations contribute to the establishment of an immunosuppressive microenvironment. We also explore potential therapeutic strategies targeting metabolic vulnerabilities in cancer cells to enhance immune-mediated anti-tumour responses. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02044861, NCT03163667, NCT04265534, NCT02071927, NCT02903914, NCT03314935, NCT03361228, NCT03048500, NCT03311308, NCT03800602, NCT04414540, NCT02771626, NCT03994744, NCT03229278, NCT04899921.

IL-6 and INF-γ Mediated Immune Responses in Mice Induced by Campylobacter jejuni Bacterial Ghosts

Background: Bacterial ghosts (BGs) a growing interest in their potential medical and pharmacological uses in recent years which is just. The empty bacterial envelopes Absent its internal substance .in this study using BGs for campylobacter jejuni which is curved, non- spore -forming, gram -negative rods that measure approximately 0.2 to 0.9µ₥×0.5 to 5.0 µ₥. Enteric campylobacter may appear as long spirals or S-or seagull -wing shapes. these organisms may appear as coccobacilli in smears prepared older cultures. Methods: On gram stained smears, these organisms stain poorly for better visualization carbol- fuchsin is recommended as a counterstain, if safranin is used, counterstaining should be extended to 2 to 3 minutes campylobacter spp. is motil. There are two methods for preparation of (BGs) either by E-lysis gene creating a lysis tunnel structure inside the active bacteria's envelope. Or by using minimum inhibition concentration and minimum growth concentration for chemical compounds (MIC), (MGC) in a row. The ideal circumstances for the generation of BGs were mapped using the Plackett-Burman experimental design using two experimental. Results: A spectrophotometer was used to measure the amount of DNA and protein released. The whole experiment was divided into three steps: in the first step all the chemical reagents except H2O2 were added to bacterial suspension, in the second step only H2O2, and in the third step, the cell pellets reconstituted in 60% ethanol and kept at room temperature for thirty minutes with gentle swirl of the cells for thirty seconds every five minutes. Cell pellets were gathered and cleaned again using the same procedure as mentioned. It was assured that no living cells were left behind in the bacterial spoon by cultivation using N.B. after the experiment. The lab animal Mic injected with BG from Campylobacter jejuni as a vaccine 28 days from the last immunization, which used the qPCR technique for the immune test, has been chosen. IL-6 and INF-G for this test. Conclusion: The immune responses accorded as a result of giving the vaccine was obtained from this the results of this research.

The Association between Gut Microbiota and Serum Biomarkers in Children with Atopic Dermatitis.

Background. Currently, it is known that the gut microbiota plays an important role in the functioning of the immune system, and a rebalancing of the bacterial community can arouse complex immune reactions and lead to immune-mediated responses in an organism, in particular, the development of atopic dermatitis (AD). Cytokines and chemokines are regulators of the innate and adaptive immune response and represent the most important biomarkers of the immune system. It is known that changes in cytokine profiles are a hallmark of many diseases, including atopy. However, it remains unclear how the bacterial imbalance disrupts the function of the immune response in AD. Objectives. We attempted to determine the role of gut bacteria in modulating cytokine pathways and their role in atopic inflammation. Methods. We sequenced the 16S rRNA gene from 50 stool samples of children aged 3-12 years who had confirmed atopic dermatitis, and 50 samples from healthy children to serve as a control group. To evaluate the immune status, we conducted a multiplex immunofluorescence assay and measured the levels of 41 cytokines and chemokines in the serum of all participants. Results. To find out whether changes in the composition of the gut microbiota were significantly associated with changes in the level of inflammatory cytokines, a correlation was calculated between each pair of bacterial family and cytokine. In the AD group, 191 correlations were significant (Spearman's correlation coefficient, p ≤ 0.05), 85 of which were positive and 106 which were negative. Conclusions. It has been demonstrated that intestinal dysbiosis is associated with alterations in cytokine profiles, specifically an increase in proinflammatory cytokine concentrations. This may indicate a systemic impact of these conditions, leading to an imbalance in the immune system's response to the Th2 type. As a result, atopic conditions may develop. Additionally, a correlation between known AD biomarkers (IL-5, IL-8, IL-13, CCL22, IFN-γ, TNF-α) and alterations in the abundance of bacterial families (Pasteurellaceae, Barnesiellaceae, Eubacteriaceae) was observed.

Infectious Neuropathies.

This review explores diverse infectious etiologies of peripheral nervous system (PNS) dysfunction, spanning sensory and motor neurons, nerves, and associated structures. Progress in viral and bacterial infections reveals multifaceted mechanisms underlying neuropathies, including viral neurotoxicity and immune-mediated responses. Latest diagnostic advances facilitate early PNS complication detection, with ongoing research offering promising treatment avenues. Emerging pathogens like severe acute respiratory syndrome coronavirus 2, Zika virus, and EV-D68 highlight the evolving infectious neuropathy paradigm. Recognizing characteristic patterns and integrating clinical factors are pivotal for precise diagnosis and tailored intervention. Challenges persist in assessment and management due to varied pathogenic mechanisms. Advancements in understanding pathogenesis have improved targeted therapies, yet gaps remain in effective treatments. Ongoing research is crucial for optimizing approaches and improving patient outcomes.

3D Bioprinting of Pig Macrophages and Human Cells Discovered the P2Y14 Receptor as a Mediator of Xenogenic Immune Responses

ABSTRACT Background The survival rate of pig lung xenotransplantation (PLXTx) recipients is severely limited by intense xenogenic immune responses, necessitating further insights into xenogeneic immunity and the development of models to study the PLXTx immune response. Methods We identified regulators of PLXTx immune response Using Gene ontology analysis. We assessed the metabolic changes and protein levels in 3D4/31 pig alveolar macrophages (PAMs) through flow cytometry and immunoblotting. To induce a xenogenic immune response, we co-cultured 3D4/31-PAMs with A549 human alveolar epithelial cells and evaluated cytokine expression using qRT-PCR. Results Gene ontology analysis identified STAT1 and alveolar macrophages as contributors to lung autoimmunity and transplant rejection. In 3D4/31-PAMs, phorbol myristate acetate-induced glycogen accumulation and cyclooxygenase-2 expression were inhibited by the P2Y14 inhibitor PPTN. Co-culturing 3D4/31-PAMs with A549 human alveolar epithelial cells via 3D bioprinting resulted in a more pronounced inflammatory response than 2D co-culture, with increased expression of genes related to the P2Y14 cascade and inflammation. This inflammatory gene expression was prevented by PPTN treatment. Conclusion Based on these results, we propose alginate bioprinting as an in vitro model for PLXTx and suggest that P2Y14 is a key regulator of xenogeneic immune responses in PAMs.

Overexpression of SEZ6L2 and Immune Infiltration in Cancer Based on Gene Image Diagnosis.

With the rapid advancement of optical image diagnostic technology, researchers are delving into the potential applications in the field of cancer diagnosis and treatment. The exact link between the SEZ6L2 gene and cancer immune infiltration remains elusive. This study aims to investigate the relationship between SEZ6L2 gene overexpression and cancer immune infiltration using optical image diagnostic technology, thereby presenting novel insights for enhancing cancer diagnosis and treatment strategies. Tissue samples obtained from cancer patients were meticulously analyzed to quantitatively assess the expression of the SEZ6L2 gene through light image diagnostic technology. Additionally, immunohistochemical techniques were employed to assess the nature and quantity of immune infiltrating cells within the cancerous tissues. The enrichment pathways were found to include complement activation, circulating immunoglobulin mediated humoral immune response, protein activation cascade, immunoglobulin complex, and immunoglobulin. In addition, the expression of SEZ6L2 is closely related to the infiltration level of tumor infiltrating immune cells (TIICs), and there is a potential relationship between the expression of SEZ6L2 and different marker genes of TIIC. Increased SEZ6L2 mRNA expression in breast invasive carcinoma was significantly associated with negative prognosis and immune invasion. SEZ6L2 may be a novel prognostic biomarker and a potential immunotherapeutic target in BRCA.

Novel bispecific antibody-drug conjugate targeting PD-L1 and B7-H3 enhances antitumor efficacy and promotes immune-mediated antitumor responses

BackgroundAntibody-drug conjugates (ADCs) offer a promising approach, combining monoclonal antibodies with chemotherapeutic drugs to target cancer cells effectively while minimizing toxicity.MethodsThis study examined the therapeutic efficacy and potential mechanisms of...

Pembrolizumab With or Without Maintenance Olaparib for Metastatic Squamous Non-SCLC That Responded to First-Line Pembrolizumab Plus Chemotherapy

IntroductionPoly (adenosine diphosphate-ribose) polymerase inhibitors can up-regulate programmed death-ligand 1 expression and promote immune-mediated responses and may improve efficacy of first-line anti‒programmed cell death protein 1‒based therapies in patients with metastatic squamous NSCLC. MethodsIn this randomized, double-blind, phase 3 trial (NCT03976362), adults with previously untreated stage IV squamous NSCLC received 4 cycles of induction therapy (pembrolizumab 200 mg every 3 weeks plus carboplatin and paclitaxel or nab-paclitaxel). Patients with disease control were randomized to 31 cycles of pembrolizumab 200 mg every 3 weeks plus olaparib 300 mg orally twice daily or placebo. Dual primary end points were progression-free survival (PFS) and overall survival (OS). PFS was tested at interim analysis 2 (the final PFS analysis); OS was tested at final analysis. ResultsA total of 851 patients received induction treatment; 296 were randomized to pembrolizumab plus olaparib and 295 to pembrolizumab plus placebo. At interim analysis 2, with median follow-up of 27.1 months, median (95% confidence interval [CI]) PFS was 8.3 (6.7‒9.7) months in the pembrolizumab plus olaparib group and 5.4 (4.1‒5.6) months in the pembrolizumab plus placebo group (hazard ratio = 0.77, 95% CI: 0.63‒0.93, p = 0.0040 [not significant at a one sided at superiority boundary of p = 0.003]). At final analysis, with median follow-up of 33.4 months, median (95% CI) OS was 19.1 (15.9‒22.2) and 18.6 (16.0‒21.6) months, respectively (hazard ratio = 1.01, 95% CI: 0.83‒1.24, p = 0.5481). Treatment-related adverse events occurred in 76.5% and 65.1% of patients, respectively. ConclusionsAdding olaparib to pembrolizumab as maintenance therapy for metastatic squamous NSCLC did not significantly improve PFS versus pembrolizumab plus placebo, neither PFS nor OS met the prespecified statistical significance boundary. No new safety signals were identified. Trial registrationClinicalTrials.gov, NCT03976362.

Macrophage microRNA-146a is a central regulator of the foreign body response to biomaterial implants

Host recognition and immune-mediated foreign body response (FBR) to biomaterials can adversely affect the functionality of implanted materials. FBR presents a complex bioengineering and medical challenge due to the lack of current treatments, making the detailed exploration of its molecular mechanisms crucial for developing new and effective therapies. To identify key molecular targets underlying the generation of FBR, here we perform analysis of microRNAs (miR) and mRNAs responses to implanted biomaterials. We found that (a) miR-146a levels inversely affect macrophage accumulation, foreign body giant cell (FBGC) formation, and fibrosis in a murine implant model; (b) macrophage-derived miR-146a is a crucial regulator of the FBR and FBGC formation, as confirmed by global and cell-specific knockout of miR-146a; (c) miR-146a modulates genes related to inflammation, fibrosis, and mechanosensing; (d) miR-146a modulates tissue stiffness near the implant during FBR as assessed by atomic force microscopy; and (e) miR-146a is linked to F-actin production and cellular traction force induction as determined by traction force microscopy, which are vital for FBGC formation. These novel findings suggest that targeting macrophage miR-146a could be a selective strategy to inhibit FBR, potentially improving the biocompatibility of biomaterials.

Polycythemia under Clozapine: A Case Study

Clozapine is widely recognized as a last-resort treatment for resistant schizophrenia, due to its efficacy in reducing persistent symptoms and lowering the risk of suicidal behavior. However, its use is limited by severe side effects, including hematological complications such as agranulocytosis. A less documented but significant complication is clozapine-induced polycythemia. This case study explores the development of polycythemia in a patient undergoing clozapine treatment for refractory schizophrenia. Despite the reduction of clozapine doses, polycythemia persisted, necessitating continued treatment due to the lack of alternative therapeutic options. The patient’s hematological abnormalities were managed through regular phlebotomies, and close collaboration between psychiatric and hematological services. This case emphasizes the importance of rigorous hematological monitoring in patients on clozapine and calls for further research into its effects on the hematopoietic system, particularly concerning polycythemia. The mechanisms underlying this association are not well understood but may involve immune-mediated responses, bone marrow alterations, and metabolic changes, necessitating multidisciplinary management for optimal patient care.

An integrative pan-cancer analysis of MASP1 and the potential clinical implications for the tumor immune microenvironment

Mannose-binding lectin-associated serine protease 1 (MASP1) plays a crucial role in the complement lectin pathway and the mediation of immune responses. However, comprehensive research on MASP1 across various cancer types has not been performed to date. This study aimed to evaluate the significance of MASP1 in pan-cancer.The Cancer Genome Atlas (TCGA), UCSC Xena and Genotype Tissue Expression (GTEx) databases were used to evaluate the expression profiles, genomic features, prognostic relevance, and immune microenvironment associations of MASP1 across 33 cancer types. We observed significant dysregulation of MASP1 expression in multiple cancers, with strong associations between MASP1 expression levels and diagnostic value as well as patient prognosis. Mechanistic insights revealed significant correlations between MASP1 levels and various immunological and genomic factors, including tumor-infiltrating immune cells (TIICs), immune-related genes, mismatch repair (MMR), tumor mutation burden (TMB), and microsatellite instability (MSI), highlighting a critical regulatory function of MASP1 within the tumor immune microenvironment (TIME). In vitro and in vivo experiments demonstrated that MASP1 expression was markedly decreased in liver hepatocellular carcinoma (LIHC). Moreover, the overexpression of MASP1 in hepatocellular carcinoma (HCC) cell lines significantly inhibited their proliferation, invasion and migration. In conclusion, MASP1 exhibits differential expression in the pan-cancer analyses and might play an important role in TIME. MASP1 is a promising prognostic biomarker and a potential target for immunological research, particularly in LIHC.

Abstract B071: Antigen-presenting cancer-associated fibroblasts are required for ICI-sensitivity in pancreatic ductal adenocarcinoma

Abstract Cancer-associated fibroblasts (CAFs) are a hallmark of many cancers and are particularly prevalent in pancreatic ductal adenocarcinoma (PDAC). This highly fibrotic environment is thought to play a role in resistance to therapy; however, attempts to target CAFs have been unsuccessful in clinical trials. Deeper insights into CAF biology have revealed that these cells are heterogeneous in origin, gene expression, and function. RNA sequencing studies have identified a subset of CAFs, antigen-presenting CAFs (apCAFs), which are defined by MHC-II and interact with CD4 T cells. Given the importance of CD4 T cells in the antitumor response in PDAC, understanding apCAF biology could demonstrate ways to promote their differentiation and enhance T cell activity.Methods: Two clones differing in sensitivity to ICIs, sKPC (sensitive) and rKPC (resistant), derived from the autochthonous KPC murine PDAC model, were implanted orthotopically into the pancreas of syngeneic C57BL/6 mice. Mice were untreated, treated with dual checkpoint inhibition, or immunized with a KRAS peptide vaccine. Tumors were harvested for TME characterization, functional assays, single-cell RNA sequencing (scRNAseq), and imaging mass cytometry (IMC). apCAFs, CD11c+, and CD4+ T cells were isolated for functional assays. Peptide-pulsed apCAFs and CD11c+ cells were cultured with naïve OT-II CD4+ T cells or sKPC tumor infiltrating CD4+ T cells. apCAF KO mice were generated by crossing PDGFRαCre and MHC-IIflx mice.Results: Immunosensitive sKPC tumors are characterized by higher immune cell and apCAF infiltration than rKPC tumors. These apCAFs activate tumor-infiltrating CD4 T cells and induce regulatory T cell (Treg) differentiation, but not production of immunosuppressive cytokines. IMC analysis shows greater proximity of apCAFs to CD4 T cells in sKPC tumors compared with rKPC tumors. Remarkably, apCAF KO mice implanted with sKPC tumors lose sensitivity to ICI. scRNAseq has uncovered a unique transcriptome of apCAFs depending on tumor of origin and time following tumor implantation, revealing potential targets by which to quantitatively and qualitatively modulate apCAFs and enhance the antitumor response. Furthermore, scRNAseq of CD4 T cells cocultured with apCAFs has shown a unique pattern of CD4 T cell gene upregulation depending on the TME from which apCAFs were isolated, which could yield strategies to modulate not only apCAFs but also CD4 T cell activity.Conclusions: apCAFs are more abundant and more proximal to CD4 T cells in immunosensitive tumors, and apCAF KO sKPC tumor-bearing mice lose sensitivity to ICI. Together these data implicate apCAFs as essential mediators of the antitumor immune response. The unique transcriptome of apCAFs and cocultured CD4 T cells depending on tumor of origin suggests multiple strategies to modulate their interactions. Although a small proportion of the TME, modulating apCAF number or function could provide a solution to the currently unmet need of new and more effective treatments for PDAC patients. Citation Format: Saumya Maru, Meredith Wetzel, Jacob T Mitchell, Nicole Gross, Lalitya Andaloori, Kathryn Howe, Emma Kartalia, Guanglan Mo, James Leatherman, Won Jin Ho, Luciane Kagohara, Elana Fertig, Edward J Pearce, Elizabeth M Jaffee. Antigen-presenting cancer-associated fibroblasts are required for ICI-sensitivity in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B071.

Expanding Prospects for Dermal Health with Bioactive Phytochemicals

The largest and most defensive organ in the human body is the skin. Skin health significantly affects the quality of life due to its crucial function in aesthetic appearance. The onset of numerous skin illnesses is frequently accompanied by chronic skin inflammation. Immune-mediated reactions defend the body against external harm and need to be quickly controlled. If unregulated, they can result in long-term cellular damage and a variety of skin diseases. Dermatological illnesses encompass a wide range of skin conditions, including but not limited to acne, eczema, psoriasis, vitiligo, dermatitis, skin cancer, and fungal infections. Phytochemicals are produced by plants as a defense mechanism against pathogens that have various biological activities and can be harnessed for therapeutic purposes. Through the quenching of free radicals and the suppression of nuclear factor-κB, phytochemicals shield the skin from damage. Phytochemicals also offer a safe topical delivery system for improving the skin and regenerative treatment. Some phytochemicals' direct molecular targets have been identified, and their underlying mechanisms of action are being researched. In this review, we summarise current studies on phytochemicals' impacts on dermal illnesses and their underlying mechanisms of action.

Double-negative T cells with a distinct transcriptomic profile are abundant in the peripheral blood of patients with breast cancer.

Double-negative T (DNT) cells comprise a distinct subset of T lymphocytes that have been implicated in immune responses. The aim of this study was to characterize the peripheral DNT population in breast cancer (BC) patients. DNT cells were isolated from the peripheral blood samples of BC patients and healthy controls by flow cytometry. The sorted DNT cells were analyzed by the Smart-seq2 for single-cell full-length transcriptome profiling. The differentially expressed genes (DEGs) between the BC and control groups were screened and functionally annotated by Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses using R. The protein-protein interaction (PPI) network of the DEGs was constructed using the CytoHubba and MCODE plug-in of Cytoscape software to identify the core genes. Survival status, DNA methylation level, immune infiltration and immune checkpoint expression were analyzed using Kaplan-Meier Plotter, UALCAN, MethSeuvr, TIMER, and TISIDB respectively. The sequencing results were verified by RT-qPCR. The percentage of DNT cells was higher in the BC patients compared to healthy controls. We identified 289 DEGs between the DNT populations of both groups. GO and KEGG pathway analyses revealed that the DEGs were mainly related to immunoglobulin mediated immune response, complement activation, and B cell receptor signaling. The PPI networks of the common DEGs were constructed using Cytoscape, and 10 core genes were identified, including TMEM176B, C1QB, C1QC, RASD2, and IFIT3. The expression levels of these genes correlated with the prognosis and immune infiltration in BC patients, and were validated by RT-qPCR (P < 0.05). DNT cells are abundant in patients with BC, and might exert anti-tumor immune responses by regulating genes such as TMEM176B and EGR1.