A myriad of functions and complex regulation of the CCR7/CCL19/CCL21 chemokine axis in the adaptive immune system

FMO2+ cancer-associated fibroblasts sensitize anti-PD-1 therapy in patients with hepatocellular carcinoma

BACKGROUND

The efficacy of immune checkpoint inhibitors (ICIs) for hepatocellular carcinoma (HCC) is limited by heterogeneity in individual responses to therapy. The heterogeneous phenotypes and crucial roles of cancer-associated fibroblasts (CAFs) in immunotherapy resistance remain largely unclear.

METHODS

A specific CAF subset was identified by integrating comprehensive single-cell RNA sequencing, spatial transcriptomics and transcriptome profiling of patients with HCC with different responses to antiprogrammed cell death protein 1 (anti-PD-1) therapy. Mouse orthotopic HCC models and a coculture system were constructed, and cytometry by time-of-flight analysis was performed to investigate the functions and mechanisms of specific CAFs in the immune context of HCC.

RESULTS

We identified a distinct flavin-containing monooxygenase 2 (FMO2)+ CAF subset associated with a favorable response to anti-PD-1 therapy and better clinical outcomes. FMO2+ CAFs increase anti-PD-1 treatment efficacy by promoting tertiary lymphoid structure formation and increasing the infiltration of CD8+ T cells and M1-like macrophages through the C-C motif chemokine ligand 19 (CCL19)-C-C motif chemokine receptor 7 axis. Mechanistically, FMO2 promotes nuclear factor kappa B/p65-mediated CCL19 expression by competitively binding to glycogen synthase 1 (GYS1) with praja ring finger ubiquitin ligase 1 (PJA1), thereby suppressing the PJA1-mediated proteasomal degradation of GYS1. CCL19 treatment potentiated the therapeutic efficacy of anti-PD-1 therapy in mouse orthotopic HCC models. A favorable immunotherapy response was observed in patients with HCC with high serum levels of CCL19.

CONCLUSIONS

We identified a novel FMO2+ CAF subset that serves as a critical regulator of microenvironmental immune properties and a predictive biomarker of the immunotherapy response in patients with HCC. CCL19 in combination with anti-PD-1 therapy may constitute a novel therapeutic strategy for HCC.

Immunological characterization of the rainbow trout bursa

The bursa of Fabricius is an immune organ, located in the caudo-dorsal surface of the cloaca, responsible for the development and maturation of avian B cells. A few years ago, a lymphoepithelial tissue placed caudal to the urogenital papilla of the cloaca analogous to the bursa was identified for the first time in Atlantic salmon (Salmo salar). The salmon bursa was demonstrated to involute around sexual maturation, as in birds. However, no primary lymphoid functions were identified in this tissue. In the current study, we have identified a homologous immune organ in rainbow trout (Oncorhynchus mykiss), a different salmonid species. This lymphoepithelium covering a blind sac, caudal to the anus, was identified in rainbow trout at different stages of development and it also experienced regression in an age-dependent way. It contained abundant IgM+ B cells and CD3+ cells and especially numerous was the number of MHC II-expressing cells. In contrast to Atlantic salmon, in rainbow trout, the bursa epithelium contained quite a few IgT+ B cells but very few IgD+ B cells. Thus, by flow cytometry, we could determine that the IgM+ B cells identified in the trout bursa had lost surface IgD expression. Interestingly, although an immunization of rainbow trout by bath barely had effects on the bursa at a transcriptional level, when fish were immunized anally with a model antigen, there were significant changes in the levels of transcription of immune genes in this tissue. These included secreted igm, secreted and membrane igd, bcma and prdm1-a2. Altogether these results evidence the existence of a bursa-like immune structure in another teleost species and provide novel information to understand the immune role of this tissue in fish, pointing to a relation to gut immune responses.

Immune status assessment based on plasma proteomics with meta graph convolutional networks

Plasma proteins, especially immune-related proteins, are vital for assessing immune health and predicting disease risks. Despite their significance, the link between these proteins and systemic immune function remains unclear. To bridge this gap, researchers developed ProMetaGCN, a model integrating meta-learning, graph convolutional networks, and protein-protein interaction (PPI) data to evaluate immune status via plasma proteomics. This framework identified 309 immune-related factors with associated biological functions and pathways. Using six machine learning methods, four algorithms (Random Forest, LightGBM, XGBoost, Lasso) were selected for immune profiling and aging analysis, revealing ADAMTS13, GDF15, and SERPINF2 as key biomarkers. Validation across two COVID-19 cohorts confirmed the model's robustness, showing immune status correlates with infection progression and recovery. Furthermore, the study proposed ImmuneAgeGap, a novel metric linking immune profiles to survival rates in non-small-cell lung cancer (NSCLC) patients. These insights advance personalized immune health strategies and disease prevention.

A comparative analysis of the dendritic cell response upon exposure to different rabies virus strains

Rabies is a viral zoonotic disease that causes over 60,000 human deaths annually worldwide. Natural infections lack a virus-specific immune response, leading to a near 100% fatality rate unless immediately treated. Rabies virus (RABV) is typically transmitted through bites from rabid dogs or other carnivores to humans and may initially interact with innate immune cells such as dendritic cells at the site of infection. This study investigates the in vitro response of human monocyte-derived dendritic cells (moDCs) exposed to two pathogenic RABV strains-silver-haired bat rabies virus (SHBRV) and dog-related rabies virus (dogRV)-and an attenuated vaccine strain (SAD P5). MoDCs were susceptible only to high doses of SHBRV and SAD P5, resulting in a more mature and migratory phenotype within the infected moDC populations. No infection was observed in moDCs exposed to dogRV. In co-culture with T cells, the presence of RABV-exposed moDCs, regardless of the strain, did not enhance T cell activation. Additionally, RABV exposure did not hinder LPS-induced moDC maturation; instead, high doses of SHBRV and SAD P5 even boosted activation levels. Overall, the findings suggest varied capabilities of RABV strains to infect and activate moDCs in vitro. However, exposure to any RABV strain did not provoke a clear antiviral state or suppression of moDC responsiveness. This lack of activation may contribute to the absence of an effective adaptive immune response in natural RABV infections.

Plasmin reduces human T cell arrest on endothelial-like cells by cleaving bound CCL21 from the cell surface

CCL21 is a key homeostatic chemokine best known for its role in lymphocyte homing and compartmentalization in the lymph node. CCL21 also plays a role in trans-endothelial migration and is known to be bound to the surface of endothelial cells in high endothelial venules and inflamed tissues. The effects of CCL21 are highly dependent on its form; full-length CCL21 can bind to the surface of endothelial cells and induce lymphocyte arrest and transendothelial migration, whereas truncated CCL21 cannot. Earlier literature indicates that plasmin can cleave CCL21 from the surface of immune cells, although the mechanism regulating this process on endothelial cells has not been studied. This study demonstrates that the human endothelial-like cell lines ECV304 (LS12) and HMEC-1 can bind the plasmin precursor plasminogen to their cell surface. Furthermore, ECV304 (LS12) cells could endogenously activate plasminogen, yielding plasmin that subsequently released cell surface CCL21. In contrast, cell-surface CCL21 was only released from HMEC-1 after exogenous tPA activated the surface-bound plasminogen. Finally, it was shown that plasmin reduced T cell adhesion to endothelial-like cells with cell surface CCL21 under shear stress conditions. Collectively, for the first time, these data demonstrate that plasmin can cleave endothelial cell surface CCL21, reducing T cell adhesion to endothelial cells under shear stress. Interestingly, this study also indicates that endothelial cells' differential expression of plasminogen activators may regulate plasmin availability and influence T-cell arrest.

Intranasal Immunization with DNA Vaccine HA-CCL19/Polyethylenimine/Chitosan Composite Provides Immune Protection Against H7N9 Infection

BACKGROUND/OBJECTIVES

The H7N9 avian influenza virus (AIV) constitutes a novel subtype of influenza virus that has emerged within the past decade. Empirical studies have demonstrated that H7N9 AIV holds the potential to trigger a human pandemic. Vaccines constitute the sole armament available to humanity in combating influenza epidemics. DNA vaccines present numerous merits; however, substantial conundrums persist regarding how to augment their immunogenicity and implement their delivery through mucosal immunization.

METHODS

In this study; BALB/c mice were utilized as a model to investigate the effect of CCL19 as a molecular adjuvant and to determine the immune response elicited by polyethylene imine (PEI) and chitosan (CS) as adjuvants during the delivery of a DNA vaccine through the nasal mucosal route.

RESULTS

Our results revealed that the CCL19 molecular adjuvant exerts a substantial immunomodulatory enhancement effect on the H7N9-HA DNA vaccine, inducing more pronounced cellular and humoral immunity. Additionally, our results indicated that the composite formed by the HA-CCL19 DNA in combination with PEI and CS effectively activates local mucosal immunity as well as systemic humoral and cellular immunity, offering 100% protection against lethal doses of homologous virus challenges.

CONCLUSIONS

CCL19 conspicuously augments the immunogenicity of the influenza virus HA DNA and conserves the integrity of the vaccine antigen. Simultaneously, CS and PEI proficiently facilitate the mucosal delivery of DNA, thereby eliciting mucosal immunity related to DNA vaccines. This study investigated the feasibility of utilizing nasal mucosa for DNA vaccine immunization, which holds significant implications for the advancement and application of DNA vaccines in public health.

Cholesterol: The driving force behind the remodeling of tumor microenvironment in colorectal cancer

Essential membrane components and metabolites with a wide range of biological roles are both produced by cholesterol metabolism. Cell-intrinsic and cell-extrinsic stimuli alter cholesterol metabolism in the tumor microenvironment (TME), which in turn encourages colorectal carcinogenesis. Metabolites produced from cholesterol play intricate roles in promoting the development of colorectal cancer (CRC) and stifling immunological responses. By altering the extracellular matrix of the main tumor, redesigning its immunological environment, and altering its mechanical stiffness, cholesterol can encourage the epithelial-mesenchymal transition of the primary tumor, opening up a pathway for tumor metastasis. Its functions in TME remodeling and tumor prevention have been recently identified. In this review we address the function of cholesterol in TME remodeling and therapeutic techniques designed to block cholesterol metabolism, and discuss how combining these strategies with already available anti-CRC medicines can have combined effects and open up new therapeutic avenues.

Local cell therapy using CCL19-expressing allogeneic mesenchymal stem cells exerts robust antitumor effects by accumulating CD103+ IL-12-producing dendritic cells and priming CD8+ T cells without involving draining lymph nodes

BACKGROUND

Immune checkpoint blockade is a promising anticancer therapy, whereas the presence of T cells in tumor sites is indispensable for its therapeutic efficacy. To promote the infiltration of T cells and dendritic cells (DCs) into the tumor, we previously proposed a local cell therapy using chemokine (C-C motif) ligand 19 (CCL19)-expressing immortalized syngeneic immortalized mesenchymal stem cells (syn-iMSC/CCL19). However, the preparation of syngeneic/autologous MSC from individual hosts limits the clinical application of this cell therapy.

METHODS

In this study, we further developed a new cell therapy using allogeneic iMSC/CCL19 (allo-iMSC/CCL19) using several tumor mice models.

RESULTS

The allo-iMSC/CCL19 therapy exerted drastic antitumor effects, in which the host's T cells were induced to respond to allogeneic MSC. In addition, the allo-iMSC/CCL19 therapy promoted the infiltration of CD103+ interleukin (IL)-12-producing DCs and priming of CD8+ T cells at tumor sites compared with that using syn-iMSC/CCL19. The antitumor effect of allo-iMSC/CCL19 therapy was not influenced by fingolimod, a sphingosine 1-phosphate receptor modulator, implying no involvement of draining lymph nodes in the priming of tumor-specific T cells.

CONCLUSION

These results suggest that allo-iMSC/CCL19 therapy exerts dramatic antitumor effects by promoting the infiltration of CD103+ IL-12-producing DCs and thereby priming tumor-specific CD8+ T cells at tumor sites. This local cell therapy could be a promising approach to anticancer therapy, particularly for overcoming dysfunction in the cancer-immunity cycle.

Chemokines Signature and T Cell Dynamics in Leishmaniasis: Molecular insight and therapeutic application

Leishmaniasis, caused by obligate intracellular Leishmania parasites, poses a significant global health burden. The control of Leishmania infection relies on an effective T cell-dependent immune response; however, various factors impede the host’s ability to mount a successful defence. Alterations in the chemokine profile, responsible for cell trafficking to the infection site, can disrupt optimal immune responses and influence the outcome of pathogenesis by facilitating parasite persistence. This review aims to emphasize the significance of the chemokine system in T cell responses and to summarize the current knowledge on the dysregulation of chemokines and their receptors associated with different subsets of T lymphocytes during Leishmaniasis. A comprehensive understanding of the dynamic nature of the chemokine system during Leishmaniasis is crucial for the development of successful immunotherapeutic approaches.

Tertiary lymphoid structures as potential biomarkers for cancer prediction and prognosis

Tertiary lymphoid structures (TLSs) are ectopic lymphocyte aggregates formed in non-lymphoid tissues, including cancers, and are loci for the generation of in situ anti-tumor immune responses, which play a crucial role in cancer control. The state of TLS presence in cancer and its composition can significantly impact the treatment response and prognosis of patients. TLSs have the potential to serve as predictive and prognostic biomarkers for cancer. However, the mechanisms underlying TLS formation in cancer and how the essential components of TLSs affect cancer are not fully understood. In this review, we summarized TLS formation in cancer, the value of the TLS in different states of existence, and its key constituents for cancer prediction and prognosis. Finally, we discussed the impact of cancer treatment on TLSs.

Breaking a dogma: orthodontic tooth movement alters systemic immunity

BACKGROUND

The prevailing paradigm posits orthodontic tooth movement (OTM) as primarily a localized inflammatory process. In this study, we endeavor to elucidate the potential ramifications of mechanical force on systemic immunity, employing a time-dependent approach.

MATERIALS AND METHODS

A previously described mouse orthodontic model was used. Ni-Ti. springs were set to move the upper 1st-molar in C57BL/6 mice and the amount of OTM was. measured by µCT. Mice were allocated randomly into four experimental groups, each. corresponding to clinical phases of OTM, relative to force application. Terminal blood. samples were collected and a comprehensive blood count test for 7 cell types as well as. proteome profiling of 111 pivotal cytokines and chemokines were conducted. Two controls. groups were included: one comprised non-treated mice and the other mice with inactivated springs.

RESULTS

Serum immuno-profiling unveiled alterations in cellular immunity, manifesting as. changes in percentages of leukocytes, monocytes, macrophages, neutrophils, and. lymphocytes, alongside key signaling factors in comparison to both control groups. The systemic cellular and molecular alterations triggered by OTM mirrored the dynamics previously described in the local immune response.

CONCLUSIONS

Although the exact interplay between local and systemic immune responses to orthodontic forces require further elucidation, our findings demonstrate a tangible link between the two. Future investigations should aim to correlate these results with human subjects, and strive to delve deeper into the specific mechanisms by which mechanical force modulates the systemic immune response.

Unveiling the immune-modulating power of THz-FEL irradiation

As terahertz (THz) technology advances, the interaction between THz radiation and the living body, particularly its effects on the immune system, has attracted extensive attention but remains poorly understood. This study firstly elucidated that exposure to 3 THz-FEL radiation markedly suppressed contact hypersensitivity reactions in mice induced by DNFB, as evidenced by a reduction in ear thickness and a discernible recovery in the Th1/Th2 cell balance. 3 THz irradiation led to cellular stress in the irradiated skin locale, increasing the levels of IL-4 and IL-10 and modulating the activity and migration of dendritic cells and mast cells. Furthermore, THz irradiation precipitated a rapid alteration in the skin lipidome, altering several categories of bioactive lipids. These findings offer new insights into the immunomodulatory effects of THz radiation on living organisms and the potential underlying mechanisms, with implications for the development of therapeutic approaches in managing skin allergic diseases.

Plasma proteomic signature of neonates in the context of placental histological chorioamnionitis

BACKGROUND

Placental histological chorioamnionitis (HCA) is recognised as a significant risk factor for various adverse neonatal outcomes. This study aims to explore if the inflammatory protein levels in neonates were associated with HCA.

METHODS

All women with singleton births from February 2020 to November 2022 were selected and divided into three groups based on maternal placental pathology results: the HCA-stage 1 group (n=24), the HCA-stage 2 group (n=16) and the control group (n=17). Olink Target 96 Inflammation Panel was used to detect the levels of 92 inflammation-related proteins in the plasma of newborns from all three groups within 24 hours after birth. We compared the protein profiles through differential protein expression analysis.

RESULTS

A total of six inflammation-related proteins exhibited significant differences between the HCA-stage 1 and the control group. Specifically, TRANCE and CST5 were significantly upregulated (p=0.006, p=0.025, respectively), whereas the expression of IFN-gamma, CXCL9, CXCL10 and CCL19 was significantly downregulated (p=0.040, p=0.046, p=0.007, p=0.006, respectively). HCA-stage 2 newborns had significantly elevated levels of CD5 and CD6 and decreased IFN-gamma, CXCL10 and CCL19 in comparison to controls. These differential proteins were significantly enriched in positive regulation of cytokine activity, leucocyte chemotaxis and positive regulation of T-cell activation pathway-related Gene Ontology terms. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that viral protein interaction with cytokine and cytokine receptor, interleukin-17/NF-kappa B/toll-like receptor/chemokine signalling pathway, and cytokine-cytokine receptor interaction exhibited significant differences. Spearman analysis demonstrated a significant positive connection between the levels of CD6 and CD5 proteins, not only in neonatal leucocytes but also in maternal leucocytes. Additionally, CD6 was found to be associated with neonatal birth weight.

CONCLUSIONS

In conclusion, placental histological changes associated with chorioamnionitis appear to influence the expression of inflammatory proteins in offspring. Notably, CD6 and CD5 proteins may potentially contribute to the pathogenesis of HCA-related neonatal diseases.

CCL19-producing fibroblasts promote tertiary lymphoid structure formation enhancing anti-tumor IgG response in colorectal cancer liver metastasis

Tertiary lymphoid structures (TLSs) are associated with enhanced immunity in tumors. However, their formation and functions in colorectal cancer liver metastasis (CRLM) remain unclear. Here, we reveal that intra- and peri-tumor mature TLSs (TLS+) are associated with improved clinical outcomes than TLS- tumors. Using single-cell-RNA-sequencing and spatial-enhanced-resolution-omics-sequencing (Stereo-seq), we reveal that TLS+ tumors are enriched with IgG+ plasma cells (PCs), while TLS- tumors are characterized with IgA+ PCs. By generating TLS-associated PC-derived monoclonal antibodies in vitro, we show that TLS-PCs secrete tumor-targeting antibodies. As the proof-of-concept, we demonstrate the anti-tumor activities of TLS-PC-mAb6 antibody in humanized mouse model of colorectal cancer. We identify a fibroblast lineage secreting CCL19 that facilitates lymphocyte trafficking to TLSs. CCL19 treatment promotes TLS neogenesis and prevents tumor growth in mice. Our data uncover the central role of CCL19+ fibroblasts in TLS formation, which in turn generates therapeutic antibodies to restrict CRLM.

Bioinformatics analysis reveals CCR7 as a potential biomarker for predicting CKD progression

Chronic kidney disease (CKD) inevitably progresses to end-stage renal disease if intervention does not occur timely. However, there are limitations in predicting the progression of CKD by solely relying on changes in renal function. A biomarker with high sensitivity and specificity that can predict CKD progression early is required. We used the online Gene Expression Omnibus microarray dataset GSE45980 to identify differentially expressed genes (DEGs) in patients with progressive and stable CKD. We then performed functional enrichment and protein-protein interaction network analysis on DEGs and identified key genes. Finally, the expression patterns of key genes were verified using the GSE60860 dataset, and the receiver operating characteristic curve analysis was performed to clarify their predictive ability of progressive CKD. Ultimately, we verified the expression profiles of these hub genes in an in vitro renal interstitial fibrosis model by real-time PCR and western blot analysis. Differential expression analysis identified 50 upregulated genes and 47 downregulated genes. The results of the functional enrichment analysis revealed that upregulated DEGs were mainly enriched in immune response, inflammatory response, and NF-κB signaling pathways, whereas downregulated DEGs were mainly related to angiogenesis and the extracellular environment. Protein-protein interaction network and key gene analysis identified CCR7 as the most important gene. CCR7 mainly plays a role in immune response, and its only receptors, CCL19 and CCL21, have also been identified as DEGs. The receiver operating characteristic curve analysis of CCR7, CCL19, and CCL21 found that CCR7 and CCL19 present good disease prediction ability. CCR7 may be a stable biomarker for predicting CKD progression, and the CCR7-CCL19/CCL21 axis may be a therapeutic target for end-stage renal disease. However, further experiments are needed to explore the relationship between these genes and CKD.

Formation of the junctions between lymph follicles in the Peyer's patches even before postweaning activation

Peyer's patches (PPs), which contain an abundance of B and T cells, play a key role in inducing pivotal immune responses in the intestinal tract. PPs are defined as aggregated lymph follicles, which consist of multiple lymph follicles (LFs) that may interact with each other in a synergistic manner. LFs are thought to be spherical in shape; however, the characteristics of their structure are not fully understood. To elucidate changes in the structure of PPs as individuals grow, we generated serial 2D sections from entire PPs harvested from mice at 2, 4, and 10 weeks of age and performed a 3D analysis using a software, Amira. Although the number of LFs in PPs was not changed throughout the experiment, the volume and surface area of LFs increased significantly, indicating that LFs in PPs develop continuously by recruiting immune cells, even after weaning. In response to the dramatic changes in the intestinal environment after weaning, the development of germinal centers (GCs) in LFs was observed at 4 and 10 weeks (but not 2 weeks) of age. In addition, GCs gradually began to form away from the center of LFs and close to the muscle layer where export lymphatic vessels develop. Importantly, each LF was joined to the adjacent LF; this feature was observed even in preweaning nonactivated PPs. These results suggest that PPs may have a unique organization and structure that enhance immune functions, allowing cells in LFs to have free access to adjacent LFs and egress smoothly from PPs to the periphery upon stimulation after weaning.

Organisation of the Atlantic salmon (Salmo salar) thymus and its content of Ig-expressing cells

The thymus of fishes is located as a dual organ in a rostrodorsal projection within the gill chamber and is covered by the operculum. The histological organization of the teleost fish thymus displays considerable diversity, particularly in salmonids where a clear distinction between the thymus cortex and medulla is yet to be defined. Recent interest has focused on the role of B cells in thymic function, but the presence of these cells within the salmon thymus remains poorly understood. In this morphological study, we applied in situ hybridization to investigate developing Atlantic salmon thymi for the expression of recombination activating (Rag) genes 1 and 2. We identified the location of the cortex, aligning with the previously described inner zone. Expression of IgM and IgD transcripts was predominantly observed in cells within the outer and subcapsular zones, with lesser expression in the cortex and inner zone. IgT expression was confined to a limited number of cells in the inner zone and capsule. The location of the thymus medulla could not be established. Our results are discussed in the context of the recently identified lymphoid organs, namely the intrabranchial lymphoid tissue (ILT) and the salmon bursa.

Delayed tumor-draining lymph node irradiation preserves the efficacy of combined radiotherapy and immune checkpoint blockade in models of metastatic disease

Cancer resistance to immune checkpoint inhibitors motivated investigations into leveraging the immunostimulatory properties of radiotherapy to overcome immune evasion and to improve treatment response. However, clinical benefits of radiotherapy-immunotherapy combinations have been modest. Routine concomitant tumor-draining lymph node irradiation (DLN IR) might be the culprit. As crucial sites for generating anti-tumor immunity, DLNs are indispensable for the in situ vaccination effect of radiotherapy. Simultaneously, DLN sparing is often not feasible due to metastatic spread. Using murine models of metastatic disease in female mice, here we demonstrate that delayed (adjuvant), but not neoadjuvant, DLN IR overcomes the detrimental effect of concomitant DLN IR on the efficacy of radio-immunotherapy. Moreover, we identify IR-induced disruption of the CCR7-CCL19/CCL21 homing axis as a key mechanism for the detrimental effect of DLN IR. Our study proposes delayed DLN IR as a strategy to maximize the efficacy of radio-immunotherapy across different tumor types and disease stages.

Deciphering fatty acid biosynthesis-driven molecular subtypes in pancreatic ductal adenocarcinoma with prognostic insights

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) poses a significant challenge due to its high heterogeneity and aggressiveness. Recognizing the urgency to delineate molecular subtypes, our study focused on the emerging field of lipid metabolism remodeling in PDAC, particularly exploring the prognostic potential and molecular classification associated with fatty acid biosynthesis.

METHODS

Gene set variation analysis (GSVA) and single-sample gene set enrichment analysis (ssGSEA) were performed to evaluate the dysregulation of lipid metabolism in PDAC. Univariate cox analysis and the LASSO module were used to build a prognostic risk score signature. The distinction of gene expression in different risk groups was explored by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and Weighted Gene Co-expression Network Analysis (WGCNA). The biological function of Acyl-CoA Synthetase Long Chain Family Member 5 (ACSL5), a pivotal gene within 7-hub gene signature panel, was validated through in vitro assays.

RESULTS

Our study identified a 7-hub gene signature associated with fatty acid biosynthesis-related genes (FRGs), providing a robust tool for prognosis prediction. The high-FRGs score group displayed a poorer prognosis, decreased immune cell infiltration, and a higher tumor mutation burden. Interestingly, this group exhibited enhanced responsiveness to various compounds according to the Genomics of Drug Sensitivity in Cancer (GDSC) database. Notably, ACSL5 was upregulated in PDAC and essential for tumor progression.

CONCLUSION

In conclusion, our research defined two novel fatty acid biosynthesis-based subtypes in PDAC, characterized by distinct transcriptional profiles. These subtypes not only served as prognostic indicator, but also offered valuable insights into their metastatic propensity and therapeutic potential.

Lymph Node-on-Chip Technology: Cutting-Edge Advances in Immune Microenvironment Simulation

Organ-on-a-chip technology is attracting growing interest across various domains as a crucial platform for drug screening and testing and is set to play a significant role in precision medicine research. Lymph nodes, being intricately structured organs essential for the body's adaptive immune responses to antigens and foreign particles, are pivotal in assessing the immunotoxicity of novel pharmaceuticals. Significant progress has been made in research on the structure and function of the lymphatic system. However, there is still an urgent need to develop prospective tools and techniques to delve deeper into its role in various diseases' pathological and physiological processes and to develop corresponding immunotherapeutic therapies. Organ chips can accurately reproduce the specific functional areas in lymph nodes to better simulate the complex microstructure of lymph nodes and the interactions between different immune cells, which is convenient for studying specific biological processes. This paper reviews existing lymph node chips and their design approaches. It discusses the applications of the above systems in modeling immune cell motility, cell-cell interactions, vaccine responses, drug testing, and cancer research. Finally, we summarize the challenges that current research faces in terms of structure, cell source, and extracellular matrix simulation of lymph nodes, and we provide an outlook on the future direction of integrated immune system chips.

Identification of biomarkers for abdominal aortic aneurysm in Behçet's disease via mendelian randomization and integrated bioinformatics analyses

Behçet's disease (BD) is a complex autoimmune disorder impacting several organ systems. Although the involvement of abdominal aortic aneurysm (AAA) in BD is rare, it can be associated with severe consequences. In the present study, we identified diagnostic biomarkers in patients with BD having AAA. Mendelian randomization (MR) analysis was initially used to explore the potential causal association between BD and AAA. The Limma package, WGCNA, PPI and machine learning algorithms were employed to identify potential diagnostic genes. A receiver operating characteristic curve (ROC) for the nomogram was constructed to ascertain the diagnostic value of AAA in patients with BD. Finally, immune cell infiltration analyses and single-sample gene set enrichment analysis (ssGSEA) were conducted. The MR analysis indicated a suggestive association between BD and the risk of AAA (odds ratio [OR]: 1.0384, 95% confidence interval [CI]: 1.0081-1.0696, p = 0.0126). Three hub genes (CD247, CD2 and CCR7) were identified using the integrated bioinformatics analyses, which were subsequently utilised to construct a nomogram (area under the curve [AUC]: 0.982, 95% CI: 0.944-1.000). Finally, the immune cell infiltration assay revealed that dysregulation immune cells were positively correlated with the three hub genes. Our MR analyses revealed a higher susceptibility of patients with BD to AAA. We used a systematic approach to identify three potential hub genes (CD247, CD2 and CCR7) and developed a nomogram to assist in the diagnosis of AAA among patients with BD. In addition, immune cell infiltration analysis indicated the dysregulation in immune cell proportions.

Clinical Phenotypes, Serological Biomarkers, and Synovial Features Defining Seropositive and Seronegative Rheumatoid Arthritis: A Literature Review

Rheumatoid arthritis (RA) is a chronic autoimmune disorder which can lead to long-term joint damage and significantly reduced quality of life if not promptly diagnosed and adequately treated. Despite significant advances in treatment, about 40% of patients with RA do not respond to individual pharmacological agents and up to 20% do not respond to any of the available medications. To address this large unmet clinical need, several recent studies have focussed on an in-depth histological and molecular characterisation of the synovial tissue to drive the application of precision medicine to RA. Currently, RA patients are clinically divided into "seropositive" or "seronegative" RA, depending on the presence of routinely checked antibodies. Recent work has suggested that over the last two decades, long-term outcomes have improved significantly in seropositive RA but not in seronegative RA. Here, we present up-to-date differences in epidemiology, clinical features, and serological biomarkers in seronegative versus seropositive RA and discuss how histological and molecular synovial signatures, revealed by recent large synovial biopsy-based clinical trials, may be exploited to refine the classification of RA patients, especially in the seronegative group.

Pyroptosis activates conventional type I dendritic cells to mediate the priming of highly functional anticancer T cells

BACKGROUND

Initiation of antitumor immunity is reliant on the stimulation of dendritic cells (DCs) to present tumor antigens to naïve T cells and generate effector T cells that can kill cancer cells. Induction of immunogenic cell death after certain types of cytotoxic anticancer therapies can stimulate T cell-mediated immunity. However, cytotoxic therapies simultaneously activate multiple types of cellular stress and programmed cell death; hence, it remains unknown what types of cancer cell death confer superior antitumor immunity.

METHODS

Murine cancer cells were engineered to activate apoptotic or pyroptotic cell death after Dox-induced expression of procell death proteins. Cell-free supernatants were collected to measure secreted danger signals, cytokines, and chemokines. Tumors were formed by transplanting engineered tumor cells to specifically activate apoptosis or pyroptosis in established tumors and the magnitude of immune response measured by flow cytometry. Tumor growth was measured using calipers to estimate end point tumor volumes for Kaplan-Meier survival analysis.

RESULTS

We demonstrated that, unlike apoptosis, pyroptosis induces an immunostimulatory secretome signature. In established tumors pyroptosis preferentially activated CD103+ and XCR1+ type I conventional DCs (cDC1) along with a higher magnitude and functionality of tumor-specific CD8+ T cells and reduced number of regulatory T cells within the tumor. Depletion of cDC1 or CD4+ and CD8+ T cells ablated the antitumor response leaving mice susceptible to a tumor rechallenge.

CONCLUSION

Our study highlights that distinct types of cell death yield varying immunotherapeutic effect and selective activation of pyroptosis can be used to potentiate multiple aspects of the anticancer immunity cycle.

Advances in the study of tertiary lymphoid structures in the immunotherapy of breast cancer

Breast cancer, as one of the most common malignancies in women, exhibits complex and heterogeneous pathological characteristics across different subtypes. Triple-negative breast cancer (TNBC) and HER2-positive breast cancer are two common and highly invasive subtypes within breast cancer. The stability of the breast microbiota is closely intertwined with the immune environment, and immunotherapy is a common approach for treating breast cancer.Tertiary lymphoid structures (TLSs), recently discovered immune cell aggregates surrounding breast cancer, resemble secondary lymphoid organs (SLOs) and are associated with the prognosis and survival of some breast cancer patients, offering new avenues for immunotherapy. Machine learning, as a form of artificial intelligence, has increasingly been used for detecting biomarkers and constructing tumor prognosis models. This article systematically reviews the latest research progress on TLSs in breast cancer and the application of machine learning in the detection of TLSs and the study of breast cancer prognosis. The insights provided contribute valuable perspectives for further exploring the biological differences among different subtypes of breast cancer and formulating personalized treatment strategies.

Gene Expression Profiling in Pediatric Appendicitis

Importance

Appendicitis is the most common indication for urgent surgery in the pediatric population, presenting across a range of severity and with variable complications. Differentiating simple appendicitis (SA) and perforated appendicitis (PA) on presentation may help direct further diagnostic workup and appropriate therapy selection, including antibiotic choice and timing of surgery.

Objective

To provide a mechanistic understanding of the differences in disease severity of appendicitis with the objective of developing improved diagnostics and treatments, specifically for the pediatric population.

Design, Setting, and Participants

The Gene Expression Profiling of Pediatric Appendicitis (GEPPA) study was a single-center prospective exploratory diagnostic study with transcriptomic profiling of peripheral blood collected from a cohort of children aged 5 to 17 years with abdominal pain and suspected appendicitis between November 2016 and April 2017 at the Alberta Children's Hospital in Calgary, Alberta, Canada, with data analysis reported in August 2023. There was no patient follow-up in this study.

Exposure

SA, PA, or nonappendicitis abdominal pain.

Main Outcomes and Measures

Blood transcriptomics was used to develop a hypothesis of underlying mechanistic differences between SA and PA to build mechanistic hypotheses and blood-based diagnostics.

Results

Seventy-one children (mean [SD] age, 11.8 [3.0] years; 48 [67.6%] male) presenting to the emergency department with abdominal pain and suspected appendicitis were investigated using whole-blood transcriptomics. A central role for immune system pathways was revealed in PA, including a dampening of major innate interferon responses. Gene expression changes in patients with PA were consistent with downregulation of immune response and inflammation pathways and shared similarities with gene expression signatures derived from patients with sepsis, including the most severe sepsis endotypes. Despite the challenges in identifying early biomarkers of severe appendicitis, a 4-gene signature that was predictive of PA compared to SA, with an accuracy of 85.7% (95% CI, 72.8-94.1) was identified.

Conclusions

This study found that PA was complicated by a dysregulated immune response. This finding should inform improved diagnostics of severity, early management strategies, and prevention of further postsurgical complications.

Transdermal Microneedles Alleviated Rheumatoid Arthritis by Inducing Immune Tolerance via Skin-Resident Antigen Presenting Cells

Restoring immune tolerance is the ultimate goal for rheumatoid arthritis (RA) treatment. The most reported oral or intravenous injection routes for the immunization of autoantigens cause gastrointestinal side effects, low patient compliance, and unsatisfied immune tolerance induction. Herein, the use of a transdermal microneedle patch is for the first time investigated to codeliver CII peptide autoantigen and rapamycin for reversing immune disorders of RA. The immunized microneedles efficiently recruit antigen-presenting cells particularly Langerhans cells, and induce tolerogenic dendritic cells at the administration skin site. The tolerogenic dendritic cells further homing to lymph nodes to activate systemic Treg cell differentiation, which upregulates the expression of anti-inflammatory mediators while inhibiting the polarization of Th1/2 and Th17 T cell phenotypes and the expression of inflammatory profiles. As a result, the optimized microneedles nearly completely eliminate RA symptoms and inflammatory infiltrations. Furthermore, it is demonstrated that a low dose of rapamycin is crucial for the successful induction of immune tolerance. The results indicate that a rationally designed microneedle patch is a promising strategy for immune balance restoration with increased immune tolerance induction efficiency and patient compliance.

Atypical chemokine receptor 4 (ACKR4/CCX-CKR): A comprehensive exploration across physiological and pathological landscapes in contemporary research

Atypical chemokine receptor 4 (ACKR4), also known as CCX-CKR, is a member of the chemokine receptor family that lacks typical G protein signaling activity. Instead, ACKR4 functions as a scavenger receptor that can bind and internalize a wide range of chemokines, influencing their availability and activity in the body. ACKR4 is involved in various physiological processes, such as immune cell trafficking and the development of thymus, spleen, and lymph nodes. Moreover, ACKR4 has been implicated in several pathological conditions, including cancer, heart and lung diseases. In cancer, ACKR4 plays a complex role, acting as a tumor suppressor or promoter depending on the type of cancer and the stage of the disease. For instance, ACKR4 may inhibit the growth and metastasis of breast cancer, but it may also promote the progression of hepatocellular carcinoma and gastric cancer. In inflammatory situations, ACKR4 has been found to modulate the recruitment and activation of immune cells, contributing to the pathogenesis of diseases such as myocardial infraction and pulmonary sarcoidosis. The study of ACKR4 is still ongoing, and further research is needed to fully understand its role in different physiological and pathological contexts. Nonetheless, ACKR4 represents a promising target for the development of novel therapeutic strategies for various diseases.

Single-cell sequencing analysis and multiple machine-learning models revealed the cellular crosstalk of dendritic cells and identified FABP5 and KLRB1 as novel biomarkers for psoriasis

Background

Psoriasis is an immune-mediated disorder influenced by environmental factors on a genetic basis. Despite advancements, challenges persist, including the diminishing efficacy of biologics and small-molecule targeted agents, alongside managing recurrence and psoriasis-related comorbidities. Unraveling the underlying pathogenesis and identifying valuable biomarkers remain pivotal for diagnosing and treating psoriasis.

Methods

We employed a series of bioinformatics (including single-cell sequencing data analysis and machine learning techniques) and statistical methods to integrate and analyze multi-level data. We observed the cellular changes in psoriatic skin tissues, screened the key genes Fatty acid binding protein 5 (FABP5) and The killer cell lectin-like receptor B1 (KLRB1), evaluated the efficacy of six widely prescribed drugs on psoriasis treatment in modulating the dendritic cell-associated pathway, and assessed their overall efficacy. Finally, RT-qPCR, immunohistochemistry, and immunofluorescence assays were used to validate.

Results

The regulatory influence of dendritic cells (DCs) on T cells through the CD70/CD27 signaling pathway may emerge as a significant facet of the inflammatory response in psoriasis. Notably, FABP5 and KLRB1 exhibited up-regulation and co-localization in psoriatic skin tissues and M5-induced HaCaT cells, serving as potential biomarkers influencing psoriasis development.

Conclusion

Our study analyzed the impact of DC-T cell crosstalk in psoriasis, elucidated the characterization of two biomarkers, FABP5 and KLRB1, in psoriasis, and highlighted the promise and value of tofacitinib in psoriasis therapy targeting DCs.

Preimmunization with Listeria-vectored cervical cancer vaccine candidate strains can establish specific T-cell immune memory and prevent tumorigenesis

BACKGROUND

Although HPV prophylactic vaccines can provide effective immune protection against high-risk HPV infection, studies have shown that the protective effect provided by them would decrease with the increased age of vaccination, and they are not recommended for those who are not in the appropriate age range for vaccination. Therefore, in those people who are not suitable for HPV prophylactic vaccines, it is worth considering establishing memory T-cell immunity to provide long-term immune surveillance and generate a rapid response against lesional cells to prevent tumorigenesis.

METHODS

In this study, healthy mice were preimmunized with LM∆E6E7 and LI∆E6E7, the two Listeria-vectored cervical cancer vaccine candidate strains constructed previously by our laboratory, and then inoculated with tumor cells 40 d later.

RESULTS

The results showed that preimmunization with LM∆E6E7 and LI∆E6E7 could establish protective memory T-cell immunity against tumor antigens in mice, which effectively eliminate tumor cells. 60% of mice preimmunized with vaccines did not develop tumors, and for the remaining mice, tumor growth was significantly inhibited. We found that preimmunization with vaccines may exert antitumor effects by promoting the enrichment of T cells at tumor site to exert specific immune responses, as well as inhibiting intratumoral angiogenesis and cell proliferation.

CONCLUSION

Altogether, this study suggests that preimmunization with LM∆E6E7 and LI∆E6E7 can establish memory T-cell immunity against tumor antigens in vivo, which provides a viable plan for preventing tumorigenesis and inhibiting tumor progression.

Cell atlas of the Atlantic salmon spleen reveals immune cell heterogeneity and cell-specific responses to bacterial infection

The spleen is a conserved secondary lymphoid organ that emerged in parallel to adaptive immunity in early jawed vertebrates. Recent studies have applied single cell transcriptomics to reveal the cellular composition of spleen in several species, cataloguing diverse immune cell types and subpopulations. In this study, 51,119 spleen nuclei transcriptomes were comprehensively investigated in the commercially important teleost Atlantic salmon (Salmo salar L.), contrasting control animals with those challenged with the bacterial pathogen Aeromonas salmonicida. We identified clusters of nuclei representing the expected major cell types, namely T cells, B cells, natural killer-like cells, granulocytes, mononuclear phagocytes, endothelial cells, mesenchymal cells, erythrocytes and thrombocytes. We discovered heterogeneity within several immune lineages, providing evidence for resident macrophages and melanomacrophages, infiltrating monocytes, several candidate dendritic cell subpopulations, and B cells at distinct stages of differentiation, including plasma cells and an igt + subset. We provide evidence for twelve candidate T cell subsets, including cd4+ T helper and regulatory T cells, one cd8+ subset, three γδT subsets, and populations double negative for cd4 and cd8. The number of genes showing differential expression during the early stages of Aeromonas infection was highly variable across immune cell types, with the largest changes observed in macrophages and infiltrating monocytes, followed by resting mature B cells. Our analysis provides evidence for a local inflammatory response to infection alongside B cell maturation in the spleen, and upregulation of ccr9 genes in igt + B cells, T helper and cd8+ cells, and monocytes, consistent with the recruitment of immune cell populations to the gut to deal with Aeromonas infection. Overall, this study provides a new cell-resolved perspective of the immune actions of Atlantic salmon spleen, highlighting extensive heterogeneity hidden to bulk transcriptomics. We further provide a large catalogue of cell-specific marker genes that can be leveraged to further explore the function and structural organization of the salmonid immune system.

MS-20 enhances the gut microbiota-associated antitumor effects of anti-PD1 antibody

Cancer immunotherapy has been regarded as a promising strategy for cancer therapy by blocking immune checkpoints and evoking immunity to fight cancer, but its efficacy seems to be heterogeneous among patients. Manipulating the gut microbiota is a potential strategy for enhancing the efficacy of immunotherapy. Here, we report that MS-20, also known as "Symbiota®", a postbiotic that comprises abundant microbial metabolites generated from a soybean-based medium fermented with multiple strains of probiotics and yeast, inhibited colon and lung cancer growth in combination with an anti-programmed cell death 1 (PD1) antibody in xenograft mouse models. Mechanistically, MS-20 remodeled the immunological tumor microenvironment by increasing effector CD8+ T cells and downregulating PD1 expression, which were mediated by the gut microbiota. Fecal microbiota transplantation (FMT) from mice receiving MS-20 treatment to recipient mice increased CD8+ T-cell infiltration into the tumor microenvironment and significantly improved antitumor activity when combined with anti-PD1 therapy. Notably, the abundance of Ruminococcus bromii, which increased following MS-20 treatment, was positively associated with a reduced tumor burden and CD8+ T-cell infiltration in vivo. Furthermore, an ex vivo study revealed that MS-20 could alter the composition of the microbiota in cancer patients, resulting in distinct metabolic pathways associated with favorable responses to immunotherapy. Overall, MS-20 could act as a promising adjuvant agent for enhancing the efficacy of immune checkpoint-mediated antitumor therapy.

The Impact of Innate Components on Viral Pathogenesis in the Neurotropic Coronavirus Encephalomyelitis Mouse Model

Recognition of viruses invading the central nervous system (CNS) by pattern recognition receptors (PRRs) is crucial to elicit early innate responses that stem dissemination. These innate responses comprise both type I interferon (IFN-I)-mediated defenses as well as signals recruiting leukocytes to control the infection. Focusing on insights from the neurotropic mouse CoV model, this review discusses how early IFN-I, fibroblast, and myeloid signals can influence protective anti-viral adaptive responses. Emphasis is placed on three main areas: the importance of coordinating the distinct capacities of resident CNS cells to induce and respond to IFN-I, the effects of select IFN-stimulated genes (ISGs) on host immune responses versus viral control, and the contribution of fibroblast activation and myeloid cells in aiding the access of T cells to the parenchyma. By unraveling how the dysregulation of early innate components influences adaptive immunity and viral control, this review illustrates the combined effort of resident CNS cells to achieve viral control.

A mechanistic marker-based screening tool to predict clinical immunogenicity of biologics

BACKGROUND

The efficacy and safety of therapeutic proteins are undermined by immunogenicity driven by anti-drug antibodies. Immunogenicity risk assessment is critically necessary during drug development, but current methods lack predictive power and mechanistic insight into antigen uptake and processing leading to immune response. A key mechanistic step in T-cell-dependent immune responses is the migration of mature dendritic cells to T-cell areas of lymphoid compartments, and this phenomenon is most pronounced in the immune response toward subcutaneously delivered proteins.

METHODS

The migratory potential of monocyte-derived dendritic cells is proposed to be a mechanistic marker for immunogenicity screening. Following exposure to therapeutic protein in vitro, dendritic cells are analyzed for changes in activation markers (CD40 and IL-12) in combination with levels of the chemokine receptor CXCR4 to represent migratory potential. Then a transwell assay captures the intensity of dendritic cell migration in the presence of a gradient of therapeutic protein and chemokine ligands.

RESULTS

Here, we show that an increased ability of the therapeutic protein to induce dendritic cell migration along a gradient of chemokine CCL21 and CXCL12 predicts higher immunogenic potential. Expression of the chemokine receptor CXCR4 on human monocyte-derived dendritic cells, in combination with activation markers CD40 and IL-12, strongly correlates with clinical anti-drug antibody incidence.

CONCLUSIONS

Mechanistic understanding of processes driving immunogenicity led to the development of a predictive tool for immunogenicity risk assessment of therapeutic proteins. These predictive markers could be adapted for immunogenicity screening of other biological modalities.

Chemokine- and chemokine receptor-based signature predicts immunotherapy response in female colorectal adenocarcinoma patients

The clinical significance and comprehensive characteristics of chemokines and chemokine receptors in female patients with advanced colorectal adenocarcinoma have not ever been reported. Our study explored the expression profiles of chemokines and chemokine receptors and constructed a chemokine- and chemokine receptor-based signature in female patients with advanced colorectal adenocarcinoma. Four independent cohorts containing 1335 patients were enrolled in our study. Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) analyses were performed to construct the signature. CIBERSORT was used to evaluate the landscape of immune cell infiltration. Thirty-two pairs of tissue specimens of female advanced colorectal cancer (CRC) patients and two CRC cell lines were used to validate the signature in vitro. Quantitative real-time PCR and western blotting were performed to validate the mRNA and protein expression levels of signature genes. EdU and colony formation assays were performed to examine proliferative ability. Transwell and wound healing assays were used to evaluate cell invasion and migration capacity. During the signature construction and validation process, we found that the signature was more applicable to female patients with advanced colorectal adenocarcinoma. Hence, the subsequent study mainly focused on the particular subgroup. Enrichment analyses revealed that the signature was closely related to immunity. The landscape of immune cell infiltration presented that the signature was significantly associated with T cells CD8 and neutrophils. Gene set enrichment analysis (GSEA) confirmed that the high-risk group was chiefly enriched in the tumor-promoting related pathways and biological processes, whereas the low-risk group was mainly enriched in anti-tumor immune response pathways and biological processes. The signature was closely correlated with CTLA4, PDL1, PDL2, TMB, MSI, and TIDE, indicating that our signature could serve as a robust biomarker for immunotherapy and chemotherapy response. ROC curves verified that our signature had more robust prognostic power than all immune checkpoints and immunotherapy-related biomarkers. Finally, we used 32 pairs of tissue specimens and 2 CRC cell lines to validate our signature in vitro. We first provided a robust prognostic chemokine- and chemokine receptor-based signature, which could serve as a novel biomarker for immunotherapy and chemotherapy response to guide individualized treatment for female patients with advanced colorectal adenocarcinoma.

Infection and inflammation stimulate expansion of a CD74+ Paneth cell subset to regulate disease progression

Paneth cells (PCs), a specialized secretory cell type in the small intestine, are increasingly recognized as having an essential role in host responses to microbiome and environmental stresses. Whether and how commensal and pathogenic microbes modify PC composition to modulate inflammation remain unclear. Using newly developed PC-reporter mice under conventional and gnotobiotic conditions, we determined PC transcriptomic heterogeneity in response to commensal and invasive microbes at single cell level. Infection expands the pool of CD74+ PCs, whose number correlates with auto or allogeneic inflammatory disease progressions in mice. Similar correlation was found in human inflammatory disease tissues. Infection-stimulated cytokines increase production of reactive oxygen species (ROS) and expression of a PC-specific mucosal pentraxin (Mptx2) in activated PCs. A PC-specific ablation of MyD88 reduced CD74+ PC population, thus ameliorating pathogen-induced systemic disease. A similar phenotype was also observed in mice lacking Mptx2. Thus, infection stimulates expansion of a PC subset that influences disease progression.

Correlation Analysis of Prognostic Gene Expression, Tumor Microenvironment, and Tumor-Infiltrating Immune Cells in Ovarian Cancer

Objective

Tumor microenvironment (TME) research can provide a crucial direction for the innovation and continuous improvement of novel biologic therapies for cancer. This study examined the relationship between the TME, expression profiles of the tumor-infiltrating immune cell, and prognostic gene expression in ovarian cancer (OC).

Materials and Methods

Screening of CD3E, CD3G, CD2, CD3D, CCL19, and IL2RG was performed using the bioinformatics methods.

Results

All six genes were found to participate in immune-related molecular mechanisms and could regulate the expression of tumor-infiltrating cells. A Kaplan-Meier survival analysis results demonstrated a strong association between overall survival and all gene expressions in patients with OC. CIBERSORT analysis results showed that the expression level of all genes was positively correlated with γδ T cell proportions.

Conclusion

Therefore, in the OC microenvironment, CD3E, CD3G, CD2, CD3D, CCL19, and IL2RG can be potential immunotherapy targets and prognostic markers.

High-fat diet, but not duration of lactation, increases mammary gland lymphatic vessel function and subsequent growth of inflammatory breast cancer cells

Inflammatory breast cancer (IBC) presents as rapid-onset swelling and breast skin changes caused by tumor emboli in the breast and breast skin lymphatics. IBC has been linked with obesity and duration of breastfeeding, but how these factors affect IBC tumor progression is not clear. We modeled the simultaneous effects of diet and weaning in mice on in vivo lymphatic function; on IBC tumor growth; and on aspects of the mammary gland microenvironment before and after IBC (SUM149) xenograft inoculation. We hypothesized that weaning status and diet would have synergistic effects on lymphatic function and the breast microenvironment to enhance IBC tumor growth. Changes in lymphatic structure and function were characterized with in vivo near-infrared fluorescence (NIRF) imaging. Mice were fed either a high-fat diet (HFD; 60 kcal%) or a normal/low-fat diet (LFD; 10 kcal%), bred twice, and subjected to either normal-duration nursing (NW) or forced weaning (FW). SUM149 IBC tumors were implanted at 14 months; images were obtained before and after implantation. Multiparous mice fed HFD showed increased pre-tumor lymphatic pulsing in both the FW and NW groups relative to mice fed LFD. HFD promoted tumor growth independent of weaning time (P = 0.04). Pre-tumor lymphatic pulsing was associated with tumor volume at 8 weeks (P = 0.02) and was significantly correlated with expression of the lymphatic tracking ligand CCL21 (P = 0.05, Table 1). HFD significantly increased the numbers of monocyte-derived IBA1+, CD163+, and CD11c+ cells (P < 0.0001, P < 0.0001, P = 0.0005) in the contralateral, non-tumor-bearing mammary gland. Numbers of lymphangiogenic podoplanin+/IBA1+ macrophages were increased in the ducts of HFD and FW mice (all P < 0.003). HFD in nulliparous mice had a similar increase in lymphatic pulsing at 14 weeks (P = 0.006), indicating that this functional change was independent of parity. We conclude that HFD induced increases in mammary gland lymphatic function, assessed as pulsing rate before tumor initiation, and correlated with inflammation in the mammary gland and increased SUM149 tumor growth. The relationship between diet, lymphatic pulsing, and tumor growth warrants further investigation.

Immunomodulatory properties of the lymphatic endothelium in the tumor microenvironment

The tumor microenvironment (TME) is an intricate complex and dynamic structure composed of various cell types, including tumor, stromal and immune cells. Within this complex network, lymphatic endothelial cells (LECs) play a crucial role in regulating immune responses and influencing tumor progression and metastatic dissemination to lymph node and distant organs. Interestingly, LECs possess unique immunomodulatory properties that can either promote or inhibit anti-tumor immune responses. In fact, tumor-associated lymphangiogenesis can facilitate tumor cell dissemination and metastasis supporting immunoevasion, but also, different molecular mechanisms involved in LEC-mediated anti-tumor immunity have been already described. In this context, the crosstalk between cancer cells, LECs and immune cells and how this communication can shape the immune landscape in the TME is gaining increased interest in recent years. In this review, we present a comprehensive and updated report about the immunomodulatory properties of the lymphatic endothelium within the TME, with special focus on primary tumors and tumor-draining lymph nodes. Furthermore, we outline emerging research investigating the potential therapeutic strategies targeting the lymphatic endothelium to enhance anti-tumor immune responses. Understanding the intricate mechanisms involved in LEC-mediated immune modulation in the TME opens up new possibilities for the development of innovative approaches to fight cancer.

LIGHT/TNFSF14 promotes CAR-T cell trafficking and cytotoxicity through reversing immunosuppressive tumor microenvironment

Tertiary lymphoid structures (TLSs) in tumor tissues facilitate immune cell trafficking and cytotoxicity, which benefits survival and favorable responses in immune therapy. Here, we observed a high correlation of tumor necrosis factor superfamily member 14 (LIGHT) expression with TLS signature genes, which are all markers for immune cell accumulation and better prognosis, through retrieving RNA sequencing (RNA-seq) data from patients with cancer, suggesting the potential of LIGHT in reconstituting a high immune-infiltrated tumor microenvironment. Accordingly, LIGHT co-expressed chimeric antigen receptor T (LIGHT CAR-T) cells not only showed enhanced cytotoxicity and cytokine production but also improved CCL19 and CCL21 expression by surrounding cells. And the supernatant of LIGHT CAR-T cells promoted T cell migration in a paracrine manner. Furthermore, LIGHT CAR-T cells showed superior anti-tumor efficacy and improved infiltration in comparison with conventional CAR-T cells in immunodeficient NSG mice. Accordingly, murine LIGHT-OT-1 T cells normalized tumor blood vessels and enforced intratumoral lymphoid structures in C57BL/6 syngeneic tumor mouse models, implying the potential of LIGHT CAR-T in clinical application. Taken together, our data revealed a straightforward strategy to optimize trafficking and cytotoxicity of CAR-T cells by redirecting TLSs through LIGHT expression, which has great potential to expand and optimize the application of CAR-T therapy in solid tumors.

Two CcCCL19bs orchestrate an antibacterial immune response in Yellow River carp (Cyprinus carpio haematopterus)

Chemokines are a group of chemotactic cytokines with an essential role in homeostasis as well as immunity via specific G protein-coupled receptors and atypical receptors. In our study, two Yellow River carp (Cyprinus carpio haematopterus) CCL19b genes (CcCCL19bs), tentatively named CcCCL19b_a and CcCCL19b_b, were cloned. The open reading frames (ORFs) of CcCCL19b_a and CcCCL19b_b were both 333 bp that encoded a 12 kDa protein with 110 amino acid residues. CcCCL19bs contained a signal peptide and a SCY domain with four typical conserved cysteine residues. The two CcCCL19b proteins shared high similarities with each other in both secondary and three-dimensional structure. Phylogenetic analysis showed that CcCCL19bs and other CCL19bs from tetraploid cyprinid fish were clustered into one clade. CcCCL19bs were highly expressed in gill and intestine in healthy fish, and a significant up-regulation of gene expression after Aeromonas hydrophila infection and poly(I:C) stimulation was observed in gill, liver, and head kidney. Furthermore, chemotaxis and antibacterial activity of CcCCL19bs were studied. The results indicated that recombinant CcCCL19b_a and CcCCL19b_b protein (rCcCCL19b_a and rCcCCL19b_b) exhibited significant attraction to primary head kidney leukocytes (HKLs). Meanwhile, both of rCcCCL19bs could promote the proliferation of HKLs, and significantly up-regulate the expressions of IL-1β, CCR7, and IL-6, and down-regulate the expression of IL-10 in primary HKLs. In vitro, rCcCCL19bs could bind and aggregate A. hydrophila and Staphylococcus aureus. The rCcCCL19bs exhibited significant antibacterial activity against A. hydrophila, but not S. aureus. Moreover, they inhibited the growth of A. hydrophila and S. aureus. In vivo, overexpression of CcCCL19bs contributed to the bacterial clearance. These studies suggested that CcCCL19bs orchestrate an antibacterial immune response.

NMR indicates the N-termini of PSGL1 and CCR7 bind competitively to the chemokine CCL21

Chemokines are from a family of secreted cytokines that direct the trafficking of immune cells to coordinate immune responses. Chemokines are involved in numerous disease states, including responding to infections, autoimmune disorders, and cancer metastasis. Ther are chemokines, like CCL21, that signal for cellular migration through the activation of G protein-coupled receptors, like CCR7, through interaction with the receptor's extracellular N-terminus, loops, and core of the receptor. CCL21 is involved in routine immune surveillance but can also attract metastasizing cancer cells to lymph nodes. P-selectin glycoprotein ligand 1 (PSGL1) has a role in cellular adhesion during chemotaxis and is a transmembrane signaling molecule. PSGL1 expression enhances chemotactic responses of T cells to CCL21. Here NMR studies indicate the binding sites on CCL21 for the N-termini or PSGL1 and CCR7 overlap, and binding of the N-termini of PSGL1 and CCR7 is competitive.

CCR7+ CD4 T Cell Immunosurveillance Disrupted in Chronic SIV-Induced Neuroinflammation in Rhesus Brain

CD4 T cells survey and maintain immune homeostasis in the brain, yet their differentiation states and functional capabilities remain unclear. Our approach, combining single-cell transcriptomic analysis, ATAC-seq, spatial transcriptomics, and flow cytometry, revealed a distinct subset of CCR7+ CD4 T cells resembling lymph node central memory (T CM ) cells. We observed chromatin accessibility at the CCR7, CD28, and BCL-6 loci, defining molecular features of T CM . Brain CCR7+ CD4 T cells exhibited recall proliferation and interleukin-2 production ex vivo, showcasing their functional competence. We identified the skull bone marrow as a local niche for these cells alongside other CNS border tissues. Sequestering T CM cells in lymph nodes using FTY720 led to reduced CCR7+ CD4 T cell frequencies in the cerebrospinal fluid, accompanied by increased monocyte levels and soluble markers indicating immune activation. In macaques chronically infected with SIVCL57 and experiencing viral rebound due to cessation of antiretroviral therapy, a decrease in brain CCR7+ CD4 T cells was observed, along with increased microglial activation and initiation of neurodegenerative pathways. Our findings highlight a role for CCR7+ CD4 T cells in CNS immune surveillance and their decline during chronic SIV-induced neuroinflammation highlights their responsiveness to neuroinflammatory processes.

GRAPHICAL ABSTRACT

In Brief

Utilizing single-cell and spatial transcriptomics on adult rhesus brain, we uncover a unique CCR7+ CD4 T cell subset resembling central memory T cells (T CM ) within brain and border tissues, including skull bone marrow. Our findings show decreased frequencies of this subset during SIV- induced chronic neuroinflammation, emphasizing responsiveness of CCR7+ CD4 T cells to CNS disruptions.

Highlights

CCR7+ CD4 T cells survey border and parenchymal CNS compartments during homeostasis; reduced presence of CCR7+ CD4 T cells in cerebrospinal fluid leads to immune activation, implying a role in neuroimmune homeostasis. CNS CCR7+ CD4 T cells exhibit phenotypic and functional features of central memory T cells (T CM ) including production of interleukin 2 and the capacity for rapid recall proliferation. Furthermore, CCR7+ CD4 T cells reside in the skull bone marrow. CCR7+ CD4 T cells are markedly decreased within the brain parenchyma during chronic viral neuroinflammation.

Heterodimerization of Chemoreceptors TAS1R3 and mGlu2 in Human Blood Leukocytes

The expression of canonical chemosensory receptors of the tongue, such as the heteromeric sweet taste (TAS1R2/TAS1R3) and umami taste (TAS1R1/TAS1R3) receptors, has been demonstrated in many extra-oral cells and tissues. Gene expression studies have revealed transcripts for all TAS1 and metabotropic glutamate (mGlu) receptors in different types of immune cells, where they are involved, for example, in the chemotaxis of human neutrophils and the protection of T cells from activation-induced cell death. Like other class-C G protein-coupling receptors (GPCRs), TAS1Rs and mGlu receptors form heteromers within their families. Since mGlu receptors and TAS1R1/TAS1R3 share the same ligand, monosodium glutamate (MSG), we hypothesized their hitherto unknown heteromerization across receptor families in leukocytes. Here we show, by means of immunocytochemistry and co-IP/Western analysis, that across class-C GPCR families, mGlu2 and TAS1R3 co-localize and heterodimerize in blood leukocytes. Expressing the recombinant receptors in HEK-293 cells, we validated their heterodimerization by bioluminescence resonance energy transfer. We demonstrate MSG-induced, mGlu2/TAS1R3 heteromer-dependent gain-of-function and pertussis toxin-sensitive signaling in luminescence assays. Notably, we show that mGlu2/TAS1R3 is necessary and sufficient for MSG-induced facilitation of N-formyl-methionyl-leucyl-phenylalanine-stimulated IL-8 secretion in neutrophils, using receptor-specific antagonists. In summary, our results demonstrate mGlu2/TAS1R3 heterodimerization in leukocytes, suggesting cellular function-tailored chemoreceptor combinations to modulate cellular immune responses.

Tertiary lymphoid structures and cytokines interconnections: The implication in cancer immunotherapy

Tertiary lymphoid structures (TLSs) are organized aggregates of lymphocytes and antigen-presenting cells that develop in non-lymphoid tissues during chronic inflammation, resembling the structure and features of secondary lymphoid organs. Numerous studies have shown that TLSs may be an important source of antitumor immunity within solid tumors, facilitating T cell and B cell differentiation and the subsequent production of antitumor antibodies, which are beneficial for cancer prognosis and responses to immunotherapy. The formation of TLS relies on the cytokine signaling network between heterogeneous cell populations, such as stromal cells, lymphocytes and cancer cells. The coordinated action of various cytokines drives the complex process of TLS development. In this review, we will comprehensively describe the mechanisms by which various cytokines regulate TLS formation and function, and the recent advancements and therapeutic potential of exploiting these mechanisms to induce TLS as an emerging immunotherapeutic approach or to enhance existing immunotherapy.

G protein-coupled receptor-targeting antibody-drug conjugates: Current status and future directions

In recent years, antibody-drug conjugates (ADCs) have emerged as promising anti-cancer therapeutic agents with several having already received market approval for the treatment of solid tumor and hematological malignancies. As ADC technology continues to improve and the range of indications treatable by ADCs increases, the repertoire of target antigens has expanded and will undoubtedly continue to grow. G protein-coupled receptors (GPCRs) are well-characterized therapeutic targets implicated in many human pathologies, including cancer, and represent a promising emerging target of ADCs. In this review, we will discuss the past and present therapeutic targeting of GPCRs and describe ADCs as therapeutic modalities. Moreover, we will summarize the status of existing preclinical and clinical GPCR-targeted ADCs and address the potential of GPCRs as novel targets for future ADC development.

Data structuring may prevent ambiguity and improve personalized medical prognosis

Topics expected to influence personalized medicine (PM), where medical decisions, practices, and treatments are tailored to the individual patient, are reviewed. Lack of discrimination due to different biological conditions that express similar values of numerical variables (ambiguity) is regarded to be a major potential barrier for PM. This material explores possible causes and sources of ambiguity and offers suggestions for mitigating the impacts of uncertainties. Three causes of ambiguity are identified: (1) delayed adoption of innovations, (2) inadequate emphases, and (3) inadequate processes used when new medical practices are developed and validated. One example of the first problem is the relative lack of medical research on "compositional data" -the type that characterizes leukocyte data. This omission results in erroneous use of data abundantly utilized in medicine, such as the blood cell differential. Emphasis on data output ‒not biomedical interpretation that facilitates the use of clinical data‒ exemplifies the second type of problems. Reliance on tools generated in other fields (but not validated within biomedical contexts) describes the last limitation. Because reductionism is associated with these problems, non-reductionist alternatives are reviewed as potential remedies. Data structuring (converting data into information) is considered a key element that may promote PM. To illustrate a process that includes data-information-knowledge and decision-making, previously published data on COVID-19 are utilized. It is suggested that ambiguity may be prevented or ameliorated. Provided that validations are grounded on biomedical knowledge, approaches that describe certain criteria - such as non-overlapping data intervals of patients that experience different outcomes, immunologically interpretable data, and distinct graphic patterns - can inform, at personalized bases, earlier and/or with fewer observations.

Crosstalk of Immune Cells and Platelets in an Ovarian Cancer Microenvironment and Their Prognostic Significance

Ovarian cancer (OC) is one of the deadliest gynecological cancers, largely due to the fast development of metastasis and drug resistance. The immune system is a critical component of the OC tumor microenvironment (TME) and immune cells such as T cells, NK cells, and dendritic cells (DC) play a key role in anti-tumor immunity. However, OC tumor cells are well known for evading immune surveillance by modulating the immune response through various mechanisms. Recruiting immune-suppressive cells such as regulatory T cells (Treg cells), macrophages, or myeloid-derived suppressor cells (MDSC) inhibit the anti-tumor immune response and promote the development and progression of OC. Platelets are also involved in immune evasion by interaction with tumor cells or through the secretion of a variety of growth factors and cytokines to promote tumor growth and angiogenesis. In this review, we discuss the role and contribution of immune cells and platelets in TME. Furthermore, we discuss their potential prognostic significance to help in the early detection of OC and to predict disease outcome.

Transcriptome profiling and differential expression analysis of altered immune-related genes in goldfish (Carassius auratus) infected with Aeromonas hydrophila

Goldfish (Carassius auratus) have been employed as a model organism to investigate the innate immune system and host-pathogen interactions. A Gram-negative bacterium called Aeromonas hydrophila has been found to cause mass mortality due to infection in a wide variety of fish species in the aquatic system. In this study, damages in Bowman's capsule, inflammatory tubular (proximal and distilled convoluted) structure, and glomerular necrosis were observed in A. hydrophila-infected head kidney of goldfish. To increase the better understanding of immune mechanisms of host defense against A. hydrophila, we performed a transcriptome analysis in head kidney of goldfish at 3 and 7 days of post-infection (dpi). Comparing to the control group, 4638 and 2580 differentially expressed genes (DEGs) were observed at 3 and 7 dpi, respectively. The DEGs were subsequently enriched in multiple immune-related pathways including Protein processing in endoplasmic reticulum, Insulin signaling pathway, and NOD-like receptor signaling pathway. The expression profile of immune-related genes such as TRAIL, CCL19, VDJ recombination-activating protein 1-like, Rag-1, and STING was validated by qRT-PCR. Furthermore, the levels of immune-related enzyme (LZM, AKP, SOD, and CAT) activities were examined at 3 and 7 dpi. The knowledge gained from the current study will be helpful for better understanding of early immune response in goldfish after A. hydrophila challenge, which will aid in future research on prevention strategies in teleost.

Detection of Novel Biomarkers in Pediatric Autoimmune Hepatitis by Proteomic Profiling

Autoimmune hepatitis (AIH) is characterized by immune-mediated hepatocyte injury resulting in the destruction of liver cells, causing inflammation, liver failure, and fibrosis. Pediatric (AIH) is an autoimmune inflammatory disease that usually requires immunosuppression for an extended period. Frequent relapses after treatment discontinuation demonstrate that current therapies do not control intrahepatic immune processes. This study describes targeted proteomic profiling data in patients with AIH and controls. A total of 92 inflammatory and 92 cardiometabolic plasma markers were assessed for (i) pediatric AIH versus controls, (ii) AIH type 1 versus type 2, (iii) AIH and AIH-autoimmune sclerosing cholangitis overlapping syndrome and (iv) correlations with circulating vitamin D levels in AIH. A total of 16 proteins showed a nominally significant differential abundance in pediatric patients with AIH compared to controls. No clustering of AIH subphenotypes based on all protein data was observed, and no significant correlation of vitamin D levels was observed for the identified proteins. The proteins that showed variable expression include CA1, CA3, GAS6, FCGR2A, 4E-BP1 and CCL19, which may serve as potential biomarkers for patients with AIH. CX3CL1, CXCL10, CCL23, CSF1 and CCL19 showed homology to one another and may be coexpressed in AIH. CXCL10 seems to be the central intermediary link for the listed proteins. These proteins were involved in relevant mechanistic pathways for liver diseases and immune processes in AIH pathogenesis. This is the first report on the proteomic profile of pediatric AIH. The identified markers could potentially lead to new diagnostic and therapeutic tools. Nevertheless, considering the complex pathogenesis of AIH, more extensive studies are warranted to replicate and validate the present study's findings.

An E. coli display method for characterization of peptide-sensor kinase interactions

Bacteria use two-component system (TCS) signaling pathways to sense and respond to peptides involved in host defense, quorum sensing and inter-bacterial warfare. However, little is known about the broad peptide-sensing capabilities of TCSs. In this study, we developed an Escherichia coli display method to characterize the effects of human antimicrobial peptides (AMPs) on the pathogenesis-regulating TCS PhoPQ of Salmonella Typhimurium with much higher throughput than previously possible. We found that PhoPQ senses AMPs with diverse sequences, structures and biological functions. We further combined thousands of displayed AMP variants with machine learning to identify peptide sub-domains and biophysical features linked to PhoPQ activation. Most of the newfound AMP activators induce PhoPQ in S. Typhimurium, suggesting possible roles in virulence regulation. Finally, we present evidence that PhoPQ peptide-sensing specificity has evolved across commensal and pathogenic bacteria. Our method enables new insights into the specificities, mechanisms and evolutionary dynamics of TCS-mediated peptide sensing in bacteria.