Changes In Immune Cells Research Articles

Abstract A043: Senescent CAFs modulate tumor immunity and promote breast cancer progression

Abstract Cellular senescence is characterized by a series of markers such as p16INKA4(p16) positivity and a distinctive profile of secretory factors including mitogens, cytokines, and extracellular matrix (ECM) proteins that are collectively recognized as senescence-associated secretory phenotype (SASP). Interestingly, high p16 positivity in stroma strongly correlates with ductal carcinoma in situ (DCIS) recurrence, raising the possibility that p16+ senescent stromal cells contribute to breast cancer progression. To explore the hypothesis, we carried out single-cell RNA sequencing (scRNA-seq) analyses of murine and human HER2+/ER+/TNBC tumor samples and found that senescence was restricted to a specific cancer-associated fibroblasts (CAF) subpopulation that expresses numerous SASP factors that could impact tumor immunosurveillance, including cytokine SASP factors and ECM SASP factors such as collagens. We refer to these cells as senescent CAFs (senCAFs). To investigate how senCAFs impact tumorigenesis, we crossed MMTV-PyMT (PyMT) mice that spontaneously develop mammary tumors to INK-ATTAC (INK) mice, which allows selective elimination of p16+ senescent cells. Depletion of senCAFs in PyMT/INK mice led to significantly delayed tumor onset and changes in various tumor-infiltrating immune cells including natural killer (NK) cells, both of which could be recapitulated by treating PyMT mice with a senolytic drug. Monoclonal antibody- mediated NK cell depletion in the PyMT model further indicated that NK cells are indispensable for senCAF’s tumor-promoting effect. Finally, our bulk RNA-sequencing and cytotoxicity assays revealed that ECM derived from senescent but not cycling myofibroblastic mammary fibroblasts potently inhibited NK cell killing of tumor cells. Importantly, PyMT mice treated with Losartan (DuP-753), an inhibitor for collagen I synthesis, showed lower tumor burden and improved tumor-infiltrating NK cell status. Together our data highlight that senCAFs contribute to mammary gland tumorigenesis by modulating tumor ECM and immunity and suggest that senolytic treatment may limit breast cancer progression. Citation Format: Jiayu Ye, John M. Baer, Douglas V. Faget, Vasilios A. Morikis, Qihao Ren, Anupama Melam, Ana Paula Delgado, Erik Knudsen, Agnieszka Witkiewicz, Robert S. Powers, Gregory D. Longmore, David G. DeNardo, Sheila A. Stewart. Senescent CAFs modulate tumor immunity and promote breast cancer progression [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A043.

Small heterodimer partner-interacting leucine zipper protein suppresses pain and cartilage destruction in an osteoarthritis model by modulating the AMPK/STAT3 signaling pathway.

Osteoarthritis (OA) is a degenerative joint disease caused by the breakdown of joint cartilage and adjacent bone. Joint injury, being overweight, differences in leg length, high levels of joint stress, abnormal joint or limb development, and inherited factors have been implicated in the etiology of OA. In addition to physical damage to the joint, a role for inflammatory processes has been identified as well. Small heterodimer partner-interacting leucine zipper protein (SMILE) regulates transcription and many cellular functions. Among the proteins activated by SMILE is the peroxisome proliferator-activated receptor (PPAR) γ, which mediates the activities of CD4 + T helper cells, including Th1, Th2, and Th17, as well as Treg cells. PPAR-γ binds to STAT3 to inhibit its transcription, thereby suppressing the expression of the NF-κB pathway, and in turn, the expression of the inflammatory cytokines interferon (IFN), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, which are sub-signals of STAT3 and NF-κB. OA was induced in control C57BL/6 mice and in C57BL/6-derived SMILE-overexpressing transgenic (SMILE Tg) mice. The protein expression levels in the joint and spleen tissues were analyzed by immunohistochemistry and immunofluorescence images. In addition, flow cytometry was performed for detecting changes of the changes of immune cells. Less cartilage damage and significantly reduced levels of OA biomarkers (MMP13, TIMP3 and MCP-1) were observed in SMILE Tg mice. Immunohistochemistry performed to identify the signaling pathway involved in the link between SMILE expression and OA revealed decreased levels of IL-1β, IL-6, TNF-α, and phosphorylated AMPK in synovial tissues as well as a significant decrease in phosphorylated STAT3 in both cartilage and synovium. Changes in systemic immune cells were investigated via flow cytometry to analyze splenocytes isolated from control and SMILE Tg mice. SMILE Tg mice had elevated proportions of CD4 + IL-4 + cells (Th2) and CD4 + CD25 + Foxp3 + cells (Treg) and a notable decrease in CD4 + IL-17 + cells (Th17). Our results show that overexpressed SMILE attenuates the symptoms of OA, by increasing AMPK signaling and decreasing STAT3, thus reducing the levels of inflammatory immune cells.

Immune cell changes in Helicobacter pylori infection-induced glandular epithelial cell damage of the gastric mucosa

Objective The purpose of this study was to investigate the relationship between Helicobacter pylori (H. pylori) infection-induced changes in gastric mucosal immune cells and glandular epithelial cell damage and the histopathological characteristics of these changes. Methods We performed a detailed histomorphometry and immunohistochemical analysis of a total of 1635 H. pylori-infected gastric mucosal specimens. Results Stage-wise features were as follows: Early stage of infection: H. pylori was colonized in the mucous layer, and very few neutrophils were visible in the layer. Gastric surface epithelial cell infection stage: H. pylori specifically and selectively adhered to the cytoplasm of the surface mucous cells, with the presence of a small number of neutrophils, eosinophils, and lymphocytes infiltration, which is termed early immune response. Compensatory mucous neck cell hyperplasia stage: proliferation of stem cells in the deep gastric pit and infiltration of a large number of lymphocytes in the superficial layer of lamina propria were observed, which is termed immune cell mobilization counterinsurgency. Lamina propria lesion stage: excessive upward migration of the proliferative area. Infiltration of a large number of lymphocytes, plasma cells, monocytes, macrophages, and other immune cells was observed in the whole layer of the gastric mucosa, which is termed automatic replication of immune cells. Abnormal proliferative transformation stage: presence of intranuclear milky globular body cells or signet-ring cell-like heterotypic cells at the junction of the gastric pit and the gastric gland, with proliferation of large numbers of immune cells and vacuolar degeneration of immune cells, which is termed the proliferation and degeneration of immune cells. Intraepithelial neoplasia stage: clonal hyperplasia of epithelial cells and immunosuppression. Conclusion For controlling the occurrence and development of gastric cancer and effective immune intervention, it is essential to grasp the relationship between H. pylori infection-induced changes in gastric mucosal immune cells and glandular epithelial cell damage and its histopathological characteristics.

Single-cell transcriptomic analysis reveals the commonality of immune response upon H1N1 influenza virus infection in mice and humans

Seasonal influenza A virus (IAV), particularly the H1N1 subtype, poses a significant public health threat because of its substantial morbidity and mortality rates worldwide. Understanding the immune response to H1N1 is crucial for developing effective treatments and vaccines. In this study, we deciphered the single-cell transcriptomic landscape of peripheral blood mononuclear cells (PBMCs) from H1N1-infected humans and lung tissue samples from H1N1-infected mice by mining HIN1-related single-cell RNA sequencing data from the GEO database. We observed similar changes in immune cell composition following H1N1 infection, with an increase in macrophages but a decrease in T cells in both species. Moreover, significant transcriptional changes in bystander immune cells upon H1N1 infection were identified, with the upregulation of the chemokine CCL2 in human PBMCs and increased expression of interferon-stimulated genes such as Ifit3, Ifit1 and Isg15 in mouse pulmonary immune cells. Intercellular cross-talk analysis highlighted enhanced interactions among bystander immune cells during H1N1 infection, with neutrophils in humans and macrophages in mice showing the most remarkable increases in interaction intensity. Transcription factor analysis revealed the conserved upregulation of key antiviral regulons, including STAT1 and IRF7, in T cells across both species, highlighting their pivotal roles in antiviral defense. These results suggest that humans and mice exhibit common immune responses to H1N1 infection, underscoring the similarity of vital immune mechanisms across species. The conserved immune mechanisms identified in this study provide potential therapeutic targets for enhancing antiviral immunity. Our research underscores the importance of understanding species-specific and conserved immune responses to H1N1 and offers insights that could inform the development of novel antiviral therapies and improve clinical outcomes for individuals affected by influenza.

Outcomes and inflammation changes in different types of immunocompromised patients with critically ill COVID-19 admitted to ICU: a national multicenter study

BackgroundImmunocompromised patients face higher risks of Severe Acute Respiratory Syndrome Coronavirus 2 infection and co-infections, leading to a possibility of high disease severity and poor outcomes. Conversely, immunosuppression can mitigate the excessive inflammatory response induced by the virus, potentially reducing disease severity. This study aims to investigate the prognostic differences and early inflammatory response characteristics in various types of immunocompromised patients with severe coronavirus disease 2019 (COVID-19) admitted to intensive care unit (ICU), summarize their clinical features, and explore potential mechanisms.MethodsA retrospective analysis was conducted on critically ill COVID-19 patients admitted to the ICU of 59 medical centers in mainland China during the Omicron outbreak from November 2022 to February 2023. Patients were categorized into two groups based on their immunosuppression status: immunocompromised and immunocompetent. Immunocompromised patients were further subdivided by etiology into cancer patients, solid organ transplant (SOT) patients, and other immunocompromised groups, with immunocompetent patients serving as controls. The mortality rates, respiratory support, complications, and early inflammatory cytokine dynamics upon ICU admission among different populations were analyzed.ResultsA total of 2030 critically ill COVID-19 patients admitted to ICU were included, with 242 in the immunocompromised group and 1788 in the immunocompetent group. Cancer patients had a higher median age of 69 years (IQR 59, 77), while SOT patients were generally younger and had less severe illness upon ICU admission, with a median APACHE II score of 12.0 (IQR 8.0, 20.0). Cancer patients had a twofold increased risk of death (OR = 2.02, 95% CI 1.18–3.46, P = 0.010) compared to immunocompetent patients. SOT and cancer patients exhibited higher C-reactive protein and serum ferritin levels than the immunocompetent group in their early days of ICU admission. The CD8+ T cells dynamics were inversely correlated in cancer and SOT patients, with Interleukin-6 levels consistently lower in the SOT group compared to both immunocompetent and cancer patients.ConclusionCritically ill COVID-19 patients admitted to the ICU exhibit distinct clinical outcomes based on their immunosuppression status, with cancer patients facing the highest mortality rate due to variations in inflammatory responses linked to their immunosuppression mechanisms. Monitoring dynamic changes in inflammatory markers and immune cells, particularly CD8+ T lymphocytes and IL-6, may offer valuable prognostic insights for these patients.

Global deficiency in the inflammatory chemokine receptors 1,2,3 and 5 prevents vascular dysfunction in angiotensin II-induced hypertension and selectively modulates aortic myeloid cell phenotype

Abstract Background Leukocyte migration to the vasculature and the heart plays a critical role in hypertensive immune responses and is a carefully orchestrated process, regulated by the interactions of inflammatory chemokines with their receptors, notably CCR1, CCR2, CCR3, and CCR5 (collectively termed inflammatory chemokine receptors (iCCRs)). However, the inflammatory chemokine/receptor system is characterised by redundancy, ligand sharing and overlapping expression patterns. Consequently, our understanding of the specific and combinatory roles of chemokine receptors in cardiovascular inflammation remains incomplete, thus hindering the development of targeted therapies. To address this challenge, we have utilised two novel mouse models: iREP mice, carrying fluorescent reporters of inflammatory chemokine receptor expression, and TACKO mice, in which the entire iCcr locus containing Ccr1, Ccr2, Ccr3, and Ccr5 has been deleted. Purpose To evaluate the expression pattern of iCCRs in experimental hypertension and understand how the global deletion of iCCRs impacts disease progression. Methods We induced hypertension in mice by subcutaneously implanting osmotic minipumps administering angiotensin II (Ang II) for a duration of 14 days. Single-cell RNA sequencing was utilised for investigating iCCR expression in aortas during hypertension. Additionally, we employed flow cytometry and confocal microscopy to track iCCR expression and localization in aortas and hearts obtained from iREP mice. TACKO mice were utilised to assess the effect of global iCCr deficiency on hypertensive phenotypes. Blood pressure was measured via telemetry and vascular function was assessed using myography. Vascular and heart remodelling were evaluated through histology. Molecular mechanisms were analysed using Western Blotting and RT-qPCR, while immune cell changes in the aorta were evaluated through cytometry of time-of-flight (CyTOF). Results Ang II infusion induced higher iCCRs expression levels in both the aorta and the heart in comparison with sham treatment, particularly in fibrotic areas. After Ang II-treatment, global deletion of iCCRs in TACKO mice resulted in the prevention of endothelial dysfunction (n=5/group, P<0.05) and perivascular fibrosis (n=6-9, P<0.01), and a reduction in cardiomyocyte size (n=12-16, P<0.01) compared to wild type mice. However, no significant improvements were observed in other hypertensive phenotypes, including blood pressure, heart fibrosis, vascular NO synthase, and oxidative stress. CyTOF analysis revealed reductions in inflammatory monocytes and conventional type 2 dendritic cells in TACKO aorta, accompanied by a phenotypic switch in macrophages towards a less inflammatory phenotype. Conclusion Deficiency in iCCRs confers protective effects against vascular dysfunction in experimental hypertension, primarily by selectively reducing inflammatory myeloid cell homing to the aorta.

Cladribine tablets in relapsing-remitting multiple sclerosis preferentially target B-cells

Recent studies demonstrate the efficacy of B cell-targeting therapies in managing multiple sclerosis (MS) activity, emphasizing the critical role of B cells in MS pathogenesis. CladB study aimed to quantify the temporal changes in peripheral immune cells and their activity over 96 weeks of Cladribine tablets (CladT) treatment in relapsing-remitting MS (RRMS).Ten participants (3 males, 7 females) had blood samples collected at multiple intervals (Day 0, 1, 5, then weekly for 8 weeks, biweekly for up to 24 weeks, and monthly for up to 96 weeks) for immune cell analysis, compared to a historical alemtuzumab-treated cohort. Paired cerebrospinal fluid (CSF) was also taken for various analyses, alongside clinical and brain imaging assessments.CladT depleted memory B cells, while alemtuzumab rapidly depleted T and B cells. The кFLC index decreased from 164.5 ± 227.1 to 71.3 ± 84.7 at 48 weeks (p = 0.002) and to 64.4 ± 67.3 at 96 weeks (p = 0.01). The IgG index dropped from 1.1 ± 0.5 at baseline to 0.8 ± 0.4 at 48 weeks (p = 0.014) and to 0.8 ± 0.3 at 96 weeks (p = 0.02). CSF CXCL-13 decreased from 88.6 ± 68.4 pg/mL to 39.4 ± 35.2 pg/mL at 48 weeks (p = 0.037) and 19.1 ± 11.7 pg/mL at 96 weeks (p = 0.027). CSF NfL levels were reduced at 48 weeks (p = 0.01).CladT primarily depletes memory B cells and antibody-secreting cell precursors in RRMS, leading to sustained effects on intrathecal antibody production and total IgG, and a reduction in CSF CXCL-13.

Establishing prognostic models for intrahepatic cholangiocarcinoma based on immune cells.

Intrahepatic cholangiocarcinoma (ICC) is a malignant liver tumor that is challenging to treat and manage and current prognostic models for the disease are inefficient or ineffective. Tumor-associated immune cells are critical for tumor development and progression. The main goal of this study was to establish models based on tumor-associated immune cells for predicting the overall survival of patients undergoing surgery for ICC. To establish 1-year and 3-year prognostic models for ICC after surgical resection. Immunohistochemical staining was performed for CD4, CD8, CD20, pan-cytokeratin (CK), and CD68 in tumors and paired adjacent tissues from 141 patients with ICC who underwent curative surgery. Selection of variables was based on regression diagnostic procedures and goodness-of-fit tests (PH assumption). Clinical parameters and pathological diagnoses, combined with the distribution of immune cells in tumors and paired adjacent tissues, were utilized to establish 1- and 3-year prognostic models. This is an important application of immune cells in the tumor microenvironment. CD4, CD8, CD20, and CK were included in the establishment of our prognostic model by stepwise selection, whereas CD68 was not significantly associated with the prognosis of ICC. By integrating clinical data associated with ICC, distinct prognostic models were derived for 1- and 3-year survival outcomes using variable selection. The 1-year prediction model yielded a C-index of 0.76 95% confidence interval (95%CI): 0.65-0.87 and the 3-year prediction model produced a C-index of 0.69 (95%CI: 0.65-0.73). Internal validation yielded a C-index of 0.761 (95%CI: 0.669-0.853) for the 1-year model and 0.693 (95%CI: 0.642-0.744) for the 3-year model. We developed Cox regression models for 1-year and 3-year survival predictions of patients with ICC who underwent resection, which has positive implications for establishing a more comprehensive prognostic model for ICC based on tumor immune microenvironment and immune cell changes in the future.

Methylation-based immune deconvolution in prostate cancer patients before and after radical prostatectomy.

Surgery, an established short-term immunosuppressive event, may spur dissemination of circulating tumor cells and promote the growth of micrometastases. Whether surgical treatment for prostate cancer (i.e., radical prostatectomy) leads to long-term immune changes is unknown. We characterized intra-individual changes in circulating immune cell subsets across a six-month period using serial blood samples from prostate cancer patients pre- and post-radical prostatectomy (n = 11), and from a comparison group managed with active surveillance (n = 8). Immune cell subsets for each patient at each time point were deconvoluted using genome-wide methylation data. There were no statistically significant intra-individual changes in immune cell proportions from pre- to six months post-radical prostatectomy. There were also no intra-individual changes in immune cell proportions in the active surveillance group, and no differences between treatment groups in immune cell changes over time. We observed no meaningful changes in circulating immune cell subsets six months after radical prostatectomy, suggesting that surgery-induced immune changes may not be long-lasting.

Metabolic regulation of the immune system in health and diseases: mechanisms and interventions.

Metabolism, including glycolysis, oxidative phosphorylation, fatty acid oxidation, and other metabolic pathways, impacts the phenotypes and functions of immune cells. The metabolic regulation of the immune system is important in the pathogenesis and progression of numerous diseases, such as cancers, autoimmune diseases and metabolic diseases. The concept of immunometabolism was introduced over a decade ago to elucidate the intricate interplay between metabolism and immunity. The definition of immunometabolism has expanded from chronic low-grade inflammation in metabolic diseases to metabolic reprogramming of immune cells in various diseases. With immunometabolism being proposed and developed, the metabolic regulation of the immune system can be gradually summarized and becomes more and more clearer. In the context of many diseases including cancer, autoimmune diseases, metabolic diseases, and many other disease, metabolic reprogramming occurs in immune cells inducing proinflammatory or anti-inflammatory effects. The phenotypic and functional changes of immune cells caused by metabolic regulation further affect and development of diseases. Based on experimental results, targeting cellular metabolism of immune cells becomes a promising therapy. In this review, we focus on immune cells to introduce their metabolic pathways and metabolic reprogramming, and summarize how these metabolic pathways affect immune effects in the context of diseases. We thoroughly explore targets and treatments based on immunometabolism in existing studies. The challenges of translating experimental results into clinical applications in the field of immunometabolism are also summarized. We believe that a better understanding of immune regulation in health and diseases will improve the management of most diseases.

Safety and efficacy assessment of fecal microbiota transplantation as an adjunctive treatment for IgA nephropathy: an exploratory clinical trial

To assess the safety and efficacy of fecal microbiota transplantation (FMT) as an adjunctive therapeutic intervention for IgA nephropathy (IgAN). Fifteen patients with IgA nephropathy were recruited based on inclusion and exclusion criteria and underwent FMT using enteric microbial capsules. Clinical indicators, intestinal microbiota and metabolomic profiles, as well as changes in serum immune cells and cytokines, were monitored before and after FMT. No severe adverse reactions were observed in the subjects. After FMT, there was a reduction in the 24-h urinary protein quantification in subjects. The relative abundances of Phocaeicola_vulgatus, Bacteroides_uniformis, Prevotella_copri, Phocaeicola_dorei, Bacteroides_ovatus, Bacteroides_xylanisolvens, Parabacteroides _distasonis, Bifidobacterium_pseudocatenulatum, Bacteroides_sp._HF-162, and Bifidobacterium_longum changed after FMT. In terms of intestinal metabolites, the levels of acylcarnitine18:0 (ACar.18:0), cotinine, N-arachidonoyl-L-serine, phosphatidylcholine (PC. (18:3e/22:6)), serotonin, and fumagillin showed significant changes. Flow cytometry analysis showed the absolute count of plasma B cells decreased in subjects, and this change correlated with alterations in the intestinal microbiota and metabolites. This study preliminarily evaluates the safety and efficacy of FMT in patients with IgAN. No significant adverse reactions were observed, and the administration of FMT alongside ACEI/ARB therapy was effective in reducing urinary protein levels in patients with IgAN, a process that may be associated with B-cell immunity.

Single-cell profiling of cellular changes in the somatic peripheral nerves following nerve injury.

Injury to the peripheral nervous system disconnects targets to the central nervous system, disrupts signal transmission, and results in functional disability. Although surgical and therapeutic treatments improve nerve regeneration, it is generally hard to achieve fully functional recovery after severe peripheral nerve injury. A better understanding of pathological changes after peripheral nerve injury helps the development of promising treatments for nerve regeneration. Single-cell analyses of the peripheral nervous system under physiological and injury conditions define the diversity of cells in peripheral nerves and reveal cell-specific injury responses. Herein, we review recent findings on the single-cell transcriptome status in the dorsal root ganglia and peripheral nerves following peripheral nerve injury, identify the cell heterogeneity of peripheral nerves, and delineate changes in injured peripheral nerves, especially molecular changes in neurons, glial cells, and immune cells. Cell-cell interactions in peripheral nerves are also characterized based on ligand-receptor pairs from coordinated gene expressions. The understanding of cellular changes following peripheral nerve injury at a single-cell resolution offers a comprehensive and insightful view for the peripheral nerve repair process, provides an important basis for the exploration of the key regulators of neuronal growth and microenvironment reconstruction, and benefits the development of novel therapeutic drugs for the treatment of peripheral nerve injury.

Comparative analysis of changes in immune cell in the chicken spleen across different ages using flow cytometry

BackgroundConcurrent emerging and reemerging avian infectious diseases cause multiple risk factors in poultry. A body amount studies attempted to understand pathogen-associated immunity in chickens. Recent research has made progress in identifying immune functions in chicken, there are still gaps in knowledge, especially regarding immune responses during infectious diseases. A deeper understanding in chicken immune system is critical for improving disease control strategies and vaccine development.ResultsThis study proposes analytical method for chicken splenocytes, enabling the tracking changes in T cells, monocytes, and B cells across three ages. Optimized lymphocyte-activating conditions were suggested using concanavalin A and chicken interleikin-2, which facilitate immune cell activation and proliferation. Next, splenocytes from embryonic day 18, day 5, and day 30 were compared using surface markers and flow cytometry analysis. We observed an increase in T cell subsets, including activated T cells (CD4+CD44+ and CD8+CD44+), and B cells, along with a reduced monocyte population after hatching. However, morphological changes and genetic expression of functional immune molecules were limited.ConclusionsThe present findings on chicken immune system development offer valuable insights into the avian immune system, including analytical methods and the phenotypic and functional changes in immune cells. Updated immune-boosting strategies during the early stages of life are crucial for developing preventive measures against major infectious diseases in the poultry industry.

Tumor-infiltrating immune cell profiles and changes associate with additional trastuzumab in preoperative chemotherapy for patients with HER2-positive gastric cancer

BackgroundHER2(+) gastric cancer (GC) can benefit from trastuzumab. However, the impact of additional trastuzumab in preoperative treatment on immune cells remains largely unknown.MethodsIn cohort I, immune cells were detected by immunohistochemistry in 1321 patients. Then 88 HER2(+) patients received preoperative therapy were collected as cohort II. Immune cell profiles and changes were analyzed in paired pre- and post-operative specimens using multiple immunohistochemistry staining.ResultsIn the treatment-naive GC patients (n = 1002), CD3+ and CD8+ T cell infiltration was significantly lower in the HER2(+) GC patients together with higher FoxP3+ T cells compared with HER2(−). However, FoxP3+ T and CD20+ B cell infiltration was significantly higher in HER2(+) GC after neoadjuvant chemotherapy (n = 319). The trastuzumab-exposed group had higher CD8+ T and lower FoxP3+ T cell infiltration and CD8+ T cell was even more significant in responders. Additionally, tertiary lymphoid structure (TLS) density increased in invasion margin of residual tumors. Patients with lower TLS in the tumor core or lower FoxP3+ T cells had better overall survival in the trastuzumab-exposed group.ConclusionAddition of trastuzumab modulates the immune microenvironment, suggesting the potential mechanism of the favorable outcome of anti-HER2 therapy and providing a theoretical rationale for the combinational immunotherapy in resectable HER2(+) GC patients.

Dissecting causal relationships between gut microbiome, immune cells, and brain injury: A Mendelian randomization study.

Increasing literature has affirmed that changes in the gut microbiome (GM) composition were linked to distinct brain injury (BI) through the gut-brain axis, but it is uncertain if such links reflect causality. Further, the immune cell changes mediating the impact of GM on BI are not completely understood. We made use of the summary statistics of 211 GM (MiBioGen consortium), 731 immune cells, and 2 different BIs (FinnGen consortium), namely traumatic BI (TBI) and focal BI (FBI), from the extensive genome-wide association studies to date. We executed bidirectional Mendelian randomization (MR) analyses to ascertain the causal relationships between the GM and BI, and 2-step MR to validate possible mediating immune cells. Additionally, thorough sensitivity analyses verified the heterogeneity, robustness, as well as horizontal pleiotropy of the results. Based on the results of inverse-variance weighted (IVW) and sensitivity analyses, in MR analyses, 5 specific GM taxa and 6 specific GM taxa were causally associated with FBI and TBI, respectively; 27 immunophenotypes and 39 immunophenotypes were causally associated with FBI and TBI, respectively. Remarkably, Anaerofilum, LachnospiraceaeNC2004group, RuminococcaceaeUCG004, CCR2 on myeloid dendritic cell (DC), CD123 on CD62L+ plasmacytoid DC, and CD123 on plasmacytoid DC were causally associated with TBI and FBI (all P < .040). However, our reverse MR did not indicate any influence of TBI and FBI on the specific GM. In mediation analysis, we found that the associations between Escherichia.Shigella and FBI were mediated by CD123 on CD62L + plasmacytoid DC in addition to CD123 on plasmacytoid DC, each accounting for 4.21% and 4.21%; the association between FamilyXIIIAD3011group and TBI was mediated by CCR2 on myeloid DC, with mediated proportions of 5.07%. No remarkable horizontal pleiotropy or heterogeneity of instrumental variables was detected. Our comprehensive MR analysis first provides insight into potential causal links between several specific GM taxa with FBI/TBI. Additionally, CD123 on plasmacytoid DC in conjunction with CCR2 on myeloid DC may function in gut microbiota-host crosstalk in FBI and TBI, correspondingly. Further studies are critical to unravel the underlying mechanisms of the links between GM and BI.

Dynamic changes in immune cells in humanized liver metastasis and subcutaneous xenograft mouse models

Preclinical drug efficacy and tumor microenvironment (TME) investigations often utilize humanized xenograft mouse models, yet these models typically fall short in replicating the intricate TME. We developed a humanized liver metastasis (LM) model by transplanting human peripheral blood mononuclear cells (PBMCs) and assessed it against the conventional subcutaneous (SC) xenograft model, focusing on immune cell dynamics post-transplantation and immunotherapy response. NOD-scid IL2Rgammanull(NSG) were inoculated with PBMCs to create humanized models. We induced SC and LM models using HCT116 cells, to investigate and compare the distributions and transformations of immune cell subsets, respectively. Both models were subjected to anti-PD-L1 therapy, followed by an analysis the TME analysis. The LM model demonstrated enhanced central tumor infiltration by tumor-infiltrating lymphocytes (TILs) compared to the peripheral pattern of SC model. TIL subpopulations in the LM model showed a progressive increase, contrasting with an initial rise and subsequent decline in the SC model. Post-anti-PD-L1 therapy, the LM model exhibited a significant rise in central and effector memory T cells, a response absents in the SC model. Our study highlights differential TME responses between SC and LM models and introduces a robust humanized LM model that swiftly indicates the potential efficacy of immunotherapies. These insights could streamline the preclinical evaluation of TME-targeting immunotherapeutic agents.

Inhibition of ASAP1 Modulates the Tumor Immune Microenvironment and Suppresses Lung Cancer Metastasis via the p-STAT3 Signaling Pathway.

ADP ribosylation factor guanylate kinase 1 (ASAP1), a key protein regulating cell migration and invasion, has attracted extensive attention in oncological research in recent years. This study aims to explore the effects of ASAP1 inhibition on lung cancer metastasis and its potential mechanisms, particularly how it modulates the tumor immune microenvironment through the p-STAT3 signaling pathway. In this study, shRNA technology was employed to specifically inhibit ASAP1 expression in lung cancer cell lines A549, NCI-H1299, and PC-9. The effects of ASAP1 inhibition on lung cancer cell viability, apoptosis, migration, and invasion were evaluated using CCK-8, TUNEL apoptosis detection, and cell migration and invasion assays. Furthermore, animal experiments were conducted to assess the in vivo effects of ASAP1 inhibition on lung cancer metastasis, and immunohistochemical analysis was performed to investigate changes in immune cells in lung metastasis models, further exploring its impact on the tumor immune microenvironment. The experimental results demonstrated that ASAP1 inhibition significantly reduced lung cancer cell viability, induced apoptosis in A549, NCI-H1299, and PC-9 cells, and suppressed the migration and invasion abilities of these cells. In vivo experiments revealed that ASAP1 inhibition effectively suppressed lung cancer metastasis and altered the tumor immune microenvironment by regulating immune cells. Moreover, we found that ASAP1 inhibition could decrease tumor cell proliferation and induce tumor apoptosis in lung metastasis models by inhibiting the p-STAT3 signaling pathway. This study confirms that ASAP1 inhibition can suppress lung cancer metastasis by modulating the tumor immune microenvironment through the inhibition of the p-STAT3 signaling pathway. These findings provide new targets for lung cancer treatment and a theoretical basis for developing novel strategies against lung cancer metastasis. Future research will further explore the mechanisms of ASAP1 in lung cancer metastasis and how to optimize treatment strategies for lung cancer patients by targeting ASAP1.

Simulated microgravity-induced dysregulation of cerebrospinal fluid immune homeostasis by disrupting the blood-cerebrospinal fluid barrier.

The blood-cerebrospinal fluid barrier (BCSFB) comprises the choroid plexus epithelia. It is important for brain development, maintenance, function, and especially for maintaining immune homeostasis in the cerebrospinal fluid (CSF). Although previous studies have shown that the peripheral immune function of the body is impaired upon exposure to microgravity, no studies have reported changes in immune cells and cytokines in the CSF that reflect neuroimmune status. The purpose of this study is to investigate the alterations in cerebrospinal fluid (CSF) immune homeostasis induced by microgravity and its mechanisms. This research is expected to provide basic data for brain protection of astronauts during spaceflight. The proportions of immune cells in the CSF and peripheral blood (PB) of SMG rats were analyzed using flow cytometry. Immune function was evaluated by measuring cytokine concentrations using the Luminex method. The histomorphology and ultrastructure of the choroid plexus epithelia were determined. The concentrations of intercellular junction proteins in choroid plexus epithelial cells, including vascular endothelial-cadherin (VE-cadherin), zonula occludens 1 (ZO-1), Claudin-1 and occludin, were detected using western blotting and immunofluorescence staining to characterize BCSFB injury. We found that SMG caused significant changes in the proportion of CD4 and CD8 T cells in the CSF and a significant increase in the levels of cytokines (GRO/KC, IL-18, MCP-1, and RANTES). In the PB, there was a significant decrease in the proportion of T cells and NKT cells and a significant increase in cytokine levels (GRO/KC, IL-18, MCP-1, and TNF-α). Additionally, we observed that the trends in immune markers in the PB and CSF were synchronized within specific SMG durations, suggesting that longer SMG periods (≥21 days) have a more pronounced impact on immune markers. Furthermore, 21d-SMG resulted in ultrastructural disruption and downregulated expression of intercellular junction proteins in rat choroid plexus epithelial cells. We found that SMG disrupts the BCSFB and affects the CSF immune homeostasis. This study provides new insights into the health protection of astronauts during spaceflight.

Periodic Acid Schiff Staining to Detect Mott Cells, Aberrant Plasma Cells Containing Immunoglobulin Inclusions Called Russell Bodies.

Hematoxylin and eosin staining is widely used for routine histopathological analysis under light microscopic examination to determine alterations of tissue architecture and cellular components in animal studies. Aside from hematoxylin/eosin staining, periodic acid Schiff (PAS) staining is used to detect polysaccharides and carbohydrate-rich macromolecules, and is essential in immunological fields for evaluation of glomerular lesions of kidneys in autoimmune animals. Since erythrocytes are not stained by PAS, this stain is also helpful for identifying changes in immune cells in the red pulp of the spleen, which is filled with erythrocytes. This article describes a protocol to detect Mott cells, bizarre plasma cells containing immunoglobulin inclusion bodies (Russell bodies) in the cytoplasm. The protocol can be used for formalin-fixed, paraffin-embedded tissue sections, frozen tissue sections, tissue-touch preparations, blood films, and cytocentrifuged cell smears. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Detection of Mott cells by PAS staining in formalin-fixed, paraffin-embedded tissue sections Basic Protocol 2: Detection of Mott cells by PAS staining in frozen tissue sections, touch preparations, blood films, and cytocentrifuged cell smears.

Human vascularized macrophage-islet organoids to model immune-mediated pancreatic β cell pyroptosis upon viral infection

There is a paucity of human models to study immune-mediated host damage. Here, we utilized the GeoMx spatial multi-omics platform to analyze immune cell changes in COVID-19 pancreatic autopsy samples, revealing an accumulation of proinflammatory macrophages. Single-cell RNA sequencing (scRNA-seq) analysis of human islets exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or coxsackievirus B4 (CVB4) viruses identified activation of proinflammatory macrophages and β cell pyroptosis. To distinguish viral versus proinflammatory-macrophage-mediated β cell pyroptosis, we developed human pluripotent stem cell (hPSC)-derived vascularized macrophage-islet (VMI) organoids. VMI organoids exhibited enhanced marker expression and function in both β cells and endothelial cells compared with separately cultured cells. Notably, proinflammatory macrophages within VMI organoids induced β cell pyroptosis. Mechanistic investigations highlighted TNFSF12-TNFRSF12A involvement in proinflammatory-macrophage-mediated β cell pyroptosis. This study established hPSC-derived VMI organoids as a valuable tool for studying immune-cell-mediated host damage and uncovered the mechanism of β cell damage during viral exposure.