High proportion of PD-1 and CD39 positive CD8+ tissue resident T lymphocytes correlates with better clinical outcome in resected human oesophageal adenocarcinoma.

OBJECTIVE: To understand the CD8+ tumour infiltrating lymphocyte (TIL) compartment of oesophageal adenocarcinoma (OAC) with regards to markers of lymphocyte exhaustion, tissue residency and to identify possible reasons behind differential responses to therapy. DESIGN: Tumour samples from 44 patients undergoing curative resection for OAC were assessed by flow cytometry for presence of antigen-experienced TILs and markers of activation and exhaustion. Populations of PD-1 and CD39 positive OAC TILs were sorted, and bulk RNA sequencing undertaken using a modified SmartSeq2 protocol. Flow cytometric assessment of functionality was completed. RESULTS: A higher proportion of antigen experienced CD8+ OAC TILs was associated with improved survival following surgery; while, high double positivity (DP) for PD-1 and CD39 among these TILs also correlated significantly with outcome. These DP TILs possess a minority population which is positive for the markers of exhaustion TIM3 and LAG3. Transcriptomic assessment of the PD-1 and CD39 DP TILs demonstrated enrichment for a tissue resident memory T lymphocyte (TRM) phenotype associated with improved survival in other cancers, reinforced by positivity for the canonical TRM marker CD103 by flow cytometry. This population demonstrated maintained functional capacity both in their transcriptomic profile, and on flow cytometric assessment, as well as preserved proliferative capacity. CONCLUSION: Resected OAC are variably infiltrated by PD-1 and CD39 DP TILs, an abundance of which among lymphocytes is associated with improved survival. This DP population has an increased, but still modest, frequency of TIM3 and LAG3 positivity compared to DN, and is in keeping with a functionally competent TRM phenotype.

Phenotypic profiling of human induced regulatory T cells at early differentiation: insights into distinct immunosuppressive potential.

Regulatory T cells (Tregs) play a key role in suppressing systemic effector immune responses, thereby preventing autoimmune diseases but also potentially contributing to tumor progression. Thus, there is great interest in clinically manipulating Tregs, but the precise mechanisms governing in vitro-induced Treg (iTreg) differentiation are not yet fully understood. Here, we used multiparametric mass cytometry to phenotypically profile human iTregs during the early stages of in vitro differentiation at single-cell level. A panel of 25 metal-conjugated antibodies specific to markers associated with human Tregs was used to characterize these immunomodulatory cells. We found that iTregs highly express the transcription factor FOXP3, as well as characteristic Treg-associated surface markers (e.g. CD25, PD1, CD137, CCR4, CCR7, CXCR3, and CD103). Expression of co-inhibitory factors (e.g. TIM3, LAG3, and TIGIT) increased slightly at late stages of iTreg differentiation. Further, CD103 was upregulated on a subpopulation of iTregs with greater suppressive capacity than their CD103- counterparts. Using mass-spectrometry-based proteomics, we showed that sorted CD103+ iTregs express factors associated with immunosuppression. Overall, our study highlights that during early stages of differentiation, iTregs resemble memory-like Treg features with immunosuppressive activity, and provides opportunities for further investigation into the molecular mechanisms underlying Treg function.

SARS-CoV-2 spike-specific nasal-resident CD49a+CD8+ memory T cells exert immediate effector functions with enhanced IFN-γ production.

Virus-specific nasal resident T cells are important for protection against subsequent infection with a similar virus. Here we examine the phenotypes and functions of SARS-CoV-2-specific T cells in the nasal mucosa of vaccinated individuals with breakthrough infection (BTI) or without infection. Nasal tissues are obtained from participants during sinus surgery. Analysis of activation-induced markers implicates that a considerable proportion of spike (S)-reactive nasal CD8+ T cells express CD103, a tissue-resident marker. MHC-I multimer staining is performed to analyze the ex vivo phenotype and function of SARS-CoV-2 S-specific CD8+ T cells. We detect multimer+CD8+ T cells with tissue-resident phenotypes in nasal tissue samples from vaccinees without infection as well as vaccinees with BTI. Multimer+CD8+ T cells remain present in nasal tissues over one year after the last exposure to S antigen, although the frequency decreases. Upon direct ex vivo stimulation with epitope peptides, nasal multimer+CD8+ T cells-particularly the CD49a+ subset-exhibit immediate effector functions, including IFN-γ production. CITE-seq analysis of S-reactive AIM+CD8+ T cells confirms the enhanced effector function of the CD49a+ subset. These findings indicate that among individuals previously exposed to S antigen by vaccination or BTI, S-specific nasal-resident CD49a+CD8+ memory T cells can rapidly respond to SARS-CoV-2 during infection or reinfection.

Sugar and arginine facilitate oral tolerance by ensuring the functionality of tolerogenic immune cell subsets in the intestine.

Although oral tolerance is a critical system in regulating allergic disorders, the mechanisms by which dietary factors regulate the induction and maintenance of oral tolerance remain unclear. To address this, we explored the differentiation and function of various immune cells in the intestinal immune system under fasting and ad libitum-fed conditions before oral ovalbumin (OVA) administration. Fasting mitigated OVA-specific Treg expansion, which is essential for oral tolerance induction. This abnormality mainly resulted from functional defects in the CX3CR1+ cells responsible for the uptake of luminal OVA and reduction of tolerogenic CD103+ dendritic cells. Eventually, fasting impaired the preventive effect of oral OVA administration on asthma and allergic rhinitis development. Specific food ingredients, namely carbohydrates and arginine, were indispensable for oral tolerance induction by activating glycolysis and mTOR signaling. Overall, prior food intake and nutritional signals are critical for maintaining immune homeostasis by inducing tolerance to ingested food antigens.

Tissue-resident memory CD103+CD8+ T cells in colorectal cancer: its implication as a prognostic and predictive liver metastasis biomarker.

BACKGROUND: Tissue-resident memory CD103+CD8+ T cells (CD103+CD8+ TRMs) are important components of anti-tumor immunity. However, the significance of CD103+CD8+ TRMs in colorectal cancer (CRC) and their advantages remain unclear. METHODS: Clinical data and specimens were used to evaluate the significance of CD103+CD8+ TRMs in CRC. A mouse subcutaneous tumorigenesis model and colony-formation assay were conducted to evaluate the anti-tumor effects of CD103+CD8+ TRMs. Finally, the infiltration density and function of CD103+CD8+ TRMs in the tumors were evaluated using flow cytometry. RESULTS: In this study, we showed that highly infiltrated CD103+CD8+ TRMs were associated with earlier clinical stage and negative VEGF expression in CRC patients and predicted a favorable prognosis for CRC/CRC liver metastases patients. Interestingly, we also found that CD103+CD8+ TRMs may have predictive potential for whether CRC develops liver metastasis in CRC. In addition, we found a positive correlation between the ratio of the number of α-SMA+ vessels to the sum of the number of α-SMA+ and CD31+ vessels in CRC, and the infiltration level of CD103+CD8+ TRMs. In addition, anti-angiogenic therapy promoted infiltration of CD103+CD8+ TRMs and enhanced their ability to secrete interferon (IFN)-γ, thus further improving the anti-tumor effect. Moreover, in vivo experiments showed that compared with peripheral blood CD8+ T cells, CD103+CD8+ TRMs infused back into the body could also further promote CD8+ T cells to infiltrate the tumor, and they had a stronger ability to secrete IFN-γ, which resulted in better anti-tumor effects. CONCLUSION: We demonstrated that CD103+CD8+ TRMs have the potential for clinical applications and provide new ideas for combined anti-tumor therapeutic strategies, such as anti-tumor angiogenesis therapy and CAR-T combined immunotherapy.

Lung-resident CD3-NK1.1+CD69+CD103+ Cells Play an Important Role in Bacillus Calmette-Guérin Vaccine-Induced Protective Immunity against Mycobacterium tuberculosis Infection.

Tissue-resident immune cells play important roles in local tissue homeostasis and infection control. There is no information on the functional role of lung-resident CD3-NK1.1+CD69+CD103+ cells in intranasal Bacillus Calmette-Guérin (BCG)-vaccinated and/or Mycobacterium tuberculosis (Mtb)-infected mice. Therefore, we phenotypically and functionally characterized these cells in mice vaccinated intranasally with BCG. We found that intranasal BCG vaccination increased CD3-NK1.1+ cells with a tissue-resident phenotype (CD69+CD103+) in the lungs during the first 7 d after BCG vaccination. Three months post-BCG vaccination, Mtb infection induced the expansion of CD3-NK1.1+CD69+CD103+ (lung-resident) cells in the lung. Adoptive transfer of lung-resident CD3-NK1.1+CD69+CD103+ cells from the lungs of BCG-vaccinated mice to Mtb-infected naive mice resulted in a lower bacterial burden and reduced inflammation in the lungs. Our findings demonstrated that intranasal BCG vaccination induces the expansion of CD3-NK1.1+CD69+CD103+ (lung-resident) cells to provide protection against Mtb infection.

Dynamic landscapes and protective immunity coordinated by influenza-specific lung-resident memory CD8+ T cells revealed by intravital imaging.

Lung-tissue-resident memory (TRM) CD8+ T cells are critical for heterosubtypic immunity against influenza virus (IAV) reinfection. How TRM cells surveil the lung, respond to infection, and interact with other cells remains unresolved. Here, we used IAV infection of mice in combination with intravital and static imaging to define the spatiotemporal dynamics of lung TRM cells before and after recall infection. CD69+CD103+ TRM cells preferentially localized to lung sites of prior IAV infection, where they exhibited patrolling behavior. After rechallenge, lung TRM cells formed tight clusters in an antigen-dependent manner. Transcriptomic analysis of IAV-specific TRM cells revealed the expression of several factors that regulate myeloid cell biology. In vivo rechallenge experiments demonstrated that protection elicited by TRM cells is orchestrated in part by interferon (IFN)-γ-mediated recruitment of inflammatory monocytes into the lungs. Overall, these data illustrate the dynamic landscapes of CD103+ lung TRM cells that mediate early protective immunity against IAV infection.

Expression Profiles of ITGA8 and VANGL2 Are Altered in Congenital Anomalies of the Kidney and Urinary Tract (CAKUT).

Kidney failures in infants are mostly caused by congenital anomalies of the kidney and urinary tract (CAKUT), which are among the most common congenital birth disorders worldwide when paired with cardiac abnormalities. People with CAKUT often have severe kidney failure as a result of a wide range of abnormalities that can occur alone or in conjunction with other syndromic disorders. In this study, we aimed to investigate the expression pattern of CAKUT candidate genes alpha-8 integrin (ITGA8) and Van Gogh-like 2 (VANGL2) in fetal tissues of healthy and CAKUT-affected kidneys using immunohistochemistry and immunofluorescence. We found that under CAKUT circumstances, the expressions of ITGA8 and VANGL2 are changed. Additionally, we showed that VANGL2 expression is constant during fetal aging, but ITGA8 expression varies. Moreover, compared to normal healthy kidneys (CTRL), ITGA8 is poorly expressed in duplex kidneys (DKs) and dysplastic kidneys (DYS), whereas VANGL2 is substantially expressed in dysplastic kidneys (DYS) and poorly expressed in hypoplastic kidneys (HYP). These results point to VANGL2 and ITGA8 as potential prognostic indicators for CAKUT malformations. Further research is necessary to explore the molecular mechanisms underlying this differential expression of ITGA8 and VANGL2.

CD8 + CD103 + iTregs protect against ischemia-reperfusion-induced acute kidney Injury by inhibiting pyroptosis.

The occurrence of acute kidney injury (AKI) is elevated, one of the main causes is ischemia-reperfusion (I/R). However, no specific therapy is currently available to treat I/R-induced AKI (I/R-AKI). Treg cells have been demonstrated to perform an anti-inflammatory role in a range of autoimmune and inflammatory illnesses. However, there is limited available information about the possible functions of CD8 + CD103 + iTregs in I/R-AKI. We utilized renal tubular epithelial cells (RTECs) subjected to hypoxia-reoxygenation (H/R) and I/R-AKI mouse model to investigate whether CD8 + CD103 + iTregs could attenuate AKI and the underlying mechanism. In vitro, co-cultured with CD8 + CD103 + iTregs alleviated H/R-induced cell injury. After treatment of CD8 + CD103 + iTregs rather than control cells, a significant improvement of I/R-AKI was observed in vivo, including decreased serum creatinine (sCr) and blood urea nitrogen (BUN) levels, reduced renal pathological injury, lowered tubular apoptosis and inhibition of the transition from AKI to chronic kidney disease (CKD). Mechanically, CD8 + CD103 + iTregs alleviated H/R-induced cell injury and I/R-AKI partly by suppressing RTECs pyroptosis via inhibiting the NLRP3/Caspase-1 axis. Our study provides a novel perspective on the possibility of CD8 + CD103 + iTregs for the treatment of I/R-AKI.

Integrin-α9 overexpression underlies the niche-independent maintenance of leukemia stem cells in acute myeloid leukemia.

Leukemia stem cells (LSCs) are widely believed to reside in well-characterized bone marrow (BM) niches; however, the capacity of the BM niches to accommodate LSCs is insufficient, and a significant proportion of LSCs are instead maintained in regions outside the BM. The molecular basis for this niche-independent behavior of LSCs remains elusive. Here, we show that integrin-α9 overexpression (ITGA9 OE) plays a pivotal role in the extramedullary maintenance of LSCs by molecularly mimicking the niche-interacting status, through the binding with its soluble ligand, osteopontin (OPN). Retroviral insertional mutagenesis conducted on leukemia-prone Runx-deficient mice identified Itga9 OE as a novel leukemogenic event. Itga9 OE activates Akt and p38MAPK signaling pathways. The elevated Myc expression subsequently enhances ribosomal biogenesis to overcome the cell integrity defect caused by the preexisting Runx alteration. The Itga9-Myc axis, originally discovered in mice, was further confirmed in multiple human acute myeloid leukemia (AML) subtypes, other than RUNX leukemias. In addition, ITGA9 was shown to be a functional LSC marker of the best prognostic value among 14 known LSC markers tested. Notably, the binding of ITGA9 with soluble OPN, a known negative regulator against HSC activation, induced LSC dormancy, while the disruption of ITGA9-soluble OPN interaction caused rapid cell propagation. These findings suggest that the ITGA9 OE increases both actively proliferating leukemia cells and dormant LSCs in a well-balanced manner, thereby maintaining LSCs. The ITGA9 OE would serve as a novel therapeutic target in AML.

Immunological characteristics of CD103+CD161+ T lymphocytes on chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNPs) is a heterogeneous disease characterized by local inflammation of the upper airway and sinus mucosa. T cell-mediated immune responses play irreplaceable roles in the pathogenesis of nasal polyps. CD161+ T cells have been implicated in the pathology of several diseases through cytokine production and cytotoxic activity. However, the immunological characteristics of CD161+ T cells in nasal mucosa are still not well understood, particularly in CRSwNPs. Our research revealed a notable enrichment of CD161+ T cells in nasal tissues compared to peripheral blood, with a significantly more infiltration of CD161+ T cells in CRSwNPs compared to control nasal samples. Phenotypical analysis found that CD161+ T cells predominantly co-expressed tissue-resident memory surface markers CD103, CD69, and CD45RO. CD161+CD103+ T cells demonstrated complicated effector functions, marked by elevated levels of PD-1, CTLA-4, IL-17, and IFN-γ and diminished expression of FoxP3 and CD25. Interestingly, despite CD161+ T cells was more abundant in polyp tissues compared to normal control tissues, and then further categorizing polyp samples into distinct groups based on clinical characteristics, only the recurrent CRSwNP group showed a significant reduction in CD161+CD8+ T cells compared to the primary CRSwNP group. This finding suggested the necessity for further research to comprehensively understand the underlying mechanisms and the broader significance of CD161+ T cells in the advancement and relapse of CRSwNPs.

Promoter hypermethylation-induced downregulation of ITGA7 promotes colorectal cancer proliferation and migration by activating the PI3K/AKT/NF-κB pathway.

We previously reported that integrin alpha 7 (ITGA7) was downregulated in colorectal cancer (CRC) tissues and CRC cell lines and that the lower expression of ITGA7 in CRC tissues was correlated with distant metastasis, suggesting that ITGA7 may function as a suppressor in CRC. The present research was conducted to further investigate the role and mechanisms of ITGA7 in CRC progression. First, bisulfite modification and genomic sequencing (BSP) results showed that the methylation rate of ITGA7 promoter was higher in 10 CRC tissues than in the matched normal tissues. Additionally, 5-Aza-CdR treatment increased ITGA7 expression in CRC cells. Gain-of-function assays revealed the inhibitory role of ITGA7 in CRC cell proliferation and migration. Mechanistically, RNA sequencing, RT-qPCR, and cytoplasm and nuclear separation and rescue assays indicated that knockdown of ITGA7 activated the transcription of MMP9, SETD7, and ADAM15 by enhancing the nuclear translocation of NF-κB. Moreover, CoIP and Western blot suggested a mechanistic model in which ITGA7 binds to CKAP4 to block the interaction of CKAP4 and PI3K p85α and thereby suppress the PI3K/AKT/NF-κB pathway. Accordingly, the current study suggests that ITGA7 functions as a suppressor in CRC progression and that its expression is controlled by promoter methylation.

Intraepithelial CD15 infiltration identifies high-grade anal dysplasia in people with HIV.

Men who have sex with men (MSM) with HIV are at high risk for squamous intraepithelial lesion (SIL) and anal cancer. Identifying local immunological mechanisms involved in the development of anal dysplasia could aid treatment and diagnostics. Here, we studied 111 anal biopsies obtained from 101 MSM with HIV, who participated in an anal screening program. We first assessed multiple immune subsets by flow cytometry, in addition to histological examination, in a discovery cohort. Selected molecules were further evaluated by immunohistochemistry in a validation cohort. Pathological samples were characterized by the presence of resident memory T cells with low expression of CD103 and by changes in natural killer cell subsets, affecting residency and activation. Furthermore, potentially immunosuppressive subsets, including CD15+CD16+ mature neutrophils, gradually increased as the anal lesion progressed. Immunohistochemistry verified the association between the presence of CD15 in the epithelium and SIL diagnosis for the correlation with high-grade SIL. A complex immunological environment with imbalanced proportions of resident effectors and immune-suppressive subsets characterized pathological samples. Neutrophil infiltration, determined by CD15 staining, may represent a valuable pathological marker associated with the grade of dysplasia.

T-bet deficiency and Hic1 induction override TGF-ß-dependency in the formation of CD103+ intestine-resident memory CD8+ T cells.

Transforming growth factor ß (TGF-ß) represents a well-established signal required for tissue-resident memory T cell (TRM) formation at intestinal surfaces, regulating the expression of a large collection of genes coordinately promoting intestinal TRM differentiation. The functional contribution from each TGF-ß-controlled transcription factor is not entirely known. Here, we find that TGF-ß-induced T-bet downregulation and Hic1 induction represent two critical events during intestinal TRM differentiation. Importantly, T-bet deficiency significantly rescues intestinal TRM formation in the absence of the TGF-ß receptor. Hic1 induction further strengthens TRM maturation in the absence of TGF-ß and T-bet. Our results reveal that provision of certain TGF-ß-induced molecular events can partially replace TGF-ß signaling to promote the establishment of intestinal TRMs, which allows the functional dissection of TGF-ß-induced transcriptional targets and molecular mechanisms for TRM differentiation.

CD4+T and CD8+T Cells in Uterus Exhibit Both Selective Dysfunction and Residency Signatures.

Unlike T cells in other tissues, uterine T cells must balance strong immune defense against pathogens with tolerance to semiallogeneic fetus. Our previous study fully elucidated the characteristics of γδT cells in nonpregnant uterus and the mechanism modulated by estrogen. However, comprehensive knowledge of the immunological properties of αßT (including CD4+T cells and CD8+T) cells in nonpregnancy uterus has not been acquired. In this study, we fully compared the immunological properties of αßT cells between uterus and blood using mouse and human sample. It showed that most of CD4+T cells and CD8+T cells in murine uterus and human endometrium were tissue resident memory T cells which highly expressed tissue residence markers CD69 and/or CD103. In addition, both CD4+T cells and CD8+T cells in uterus highly expressed inhibitory molecular PD-1 and cytokine IFN-γ. Uterine CD4+T cells highly expressed IL-17 and modulated by transcription factor pSTAT3. Moreover, we compared the similarities and differences between human and murine uterine T cell phenotype. Together, uterine CD4+T cells and CD8+ cells exhibited a unique mixed signature of T cell dysfunction, activation, and effector function which enabled them to balance strong immune defense against pathogens with tolerance to fetus. Our study fully elucidated the unique immunologic properties of uterine CD4+T and CD8+T cells and provided a base for further investigation of functions.

Fibroblasts with high matrix metalloproteinase 2 expression regulate CD8+ T-cell residency and inflammation via CD100 in psoriasis.

BACKGROUND: Psoriasis is a T cell-mediated chronic inflammatory skin condition characterized by the interaction of T cells with various cell types, forming an inflammatory microenvironment that sustains psoriatic inflammation. Homeostasis of these tissue-resident T cells is supported by fibroblasts, the primary structural cells in the dermis. In psoriasis, there is increased expression of matrix metalloproteinase 2 (MMP2), mediating structural alterations in skin tissues and modulating inflammation. Additionally, the CD100-plexin-B2 (PLXNB2) axis is known to enhance psoriasis inflammation via keratinocytes, and CD103 levels are associated with the severity of psoriasis upon relapse. OBJECTIVES: To elucidate the role of fibroblasts and the MMP2-CD100 axis in modulating psoriasis inflammation. METHODS: CD100 expression and function in psoriasis were assessed using immunofluorescence, enzyme-linked immunosorbent assay, single-cell transcriptome sequencing, cellular interaction analyses and quantitative reverse transcriptase polymerase chain reaction. CD8+ T cells from people with psoriasis were isolated using magnetic beads, to investigate the regulatory effect of MMP2 on CD100 expression on their membranes. Single-cell transcriptome sequencing, spatial transcriptome sequencing, mimetic timing analysis, immunofluorescence and flow cytometry were used to determine the origin of MMP2 and its impact on CD103+ CD8+ T cells. The hypotheses were further validated in vivo using MMP2 and CD100 inhibitors. RESULTS: Soluble CD100 (sCD100) was significantly upregulated in both psoriatic lesions and peripheral blood, amplifying psoriasis inflammation by promoting the production of inflammatory cytokines by keratinocytes, fibroblasts and endothelial cells via the sCD100-PLXNB2 axis. Fibroblasts that highly expressed MMP2 (MMP2hi) exacerbated psoriasis symptoms by facilitating CD100 shedding from CD8+ T-cell membranes. Additionally, it was shown that fibroblasts enhance the upregulation of the CD8+ T-cell residency factor CD103 in co-cultures with CD8+ T cells. Inhibitors targeting MMP2 and CD100 were effective in reducing inflammation in an imiquimod-induced psoriasis model. CONCLUSIONS: Our findings underscore the pivotal role of MMP2hi fibroblasts in the amplification and recurrence of inflammatory responses in psoriasis. These fibroblasts augment psoriasis inflammation through the CD100-PLXNB2 axis by facilitating CD100 shedding on CD8+ T-cell membranes and by upregulating CD103, thereby enhancing CD8+ T-cell residency.

Psoriasis is a chronic skin condition. It involves the interaction of cells of the immune system (called T cells) with other cells in the body, causing inflammation. The main structural cells in the skin are called fibroblasts. Fibroblasts are important in skin healing and disease. In psoriasis, the body produces more of an enzyme called MMP2. MMP2 brings about structural alterations in skin tissues and controls inflammation. Proteins called CD100 and PLXNB2 increase the inflammation in psoriasis through another type of skin cell called keratinocytes. We investigated the role of fibroblasts and MMP2 and CD100 in psoriasis. To do this, the production and function of CD100 were assessed using a variety of laboratory techniques. We found that by controlling the enzymes MMP2 and MMP9, fibroblasts cause the release of CD100 from some T cells, encouraging the production of substances that promote inflammation, worsening psoriasis. This also caused fibroblasts to produce more MMP2, forming a cycle that increases the inflammation seen in psoriasis. Fibroblasts were found to increase the level of another protein called CD103 on some T cells, affecting how often psoriasis flares up. Our study highlights the important role of fibroblasts that express a lot of MMP2 in the inflammation found in people with psoriasis.

M2 macrophage-derived exosomal circTMCO3 acts through miR-515-5p and ITGA8 to enhance malignancy in ovarian cancer.

Tumor-associated macrophages of the M2 phenotype promote cancer initiation and progression. Importantly, M2 macrophage-derived exosomes play key roles in the malignancy of cancer cells. Here, we report that circTMCO3 is upregulated in ovarian cancer patients, and its high expression indicates poor survival. M2-derived exosomes promote proliferation, migration, and invasion in ovarian cancer, but these effects are abolished by knockdown of circTMCO3. Furthermore, circTMCO3 functions as a competing endogenous RNA for miR-515-5p to reduce its abundance, thus upregulating ITGA8 in ovarian cancer. miR-515-5p inhibits ovarian cancer malignancy via directly downregulating ITGA8. The decreased oncogenic activity of circTMCO3-silencing exosomes is reversed by miR-515-5p knockdown or ITGA8 overexpression. Exosomal circTMCO3 promotes ovarian cancer progression in nude mice. Thus, M2 macrophage-derived exosomes promote malignancy by delivering circTMCO3 and targeting the miR-515-5p/ITGA8 axis in ovarian cancer. Our findings not only provide mechanistic insights into ovarian cancer progression, but also suggest potential therapeutic targets.

MAdCAM-1 co-stimulation combined with retinoic acid and TGF-ß induces blood CD8+ T cells to adopt a gut CD101+ TRM phenotype.

Resident memory T cells (TRMs) help control local immune homeostasis and contribute to tissue-protective immune responses. The local cues that guide their differentiation and localization are poorly defined. We demonstrate that mucosal vascular addressin cell adhesion molecule 1, a ligand for the gut-homing receptor α4ß7 integrin, in the presence of retinoic acid and transforming growth factor-ß (TGF-ß) provides a co-stimulatory signal that induces blood cluster of differentiation (CD8+ T cells to adopt a TRM-like phenotype. These cells express CD103 (integrin αE) and CD69, the two major TRM cell-surface markers, along with CD101. They also express C-C motif chemokine receptors 5 (CCR5) , C-C motif chemokine receptors 9 (CCR9), and α4ß7, three receptors associated with gut homing. A subset also expresses E-cadherin, a ligand for αEß7. Fluorescent lifetime imaging indicated an αEß7 and E-cadherin cis interaction on the plasma membrane. This report advances our understanding of the signals that drive the differentiation of CD8+ T cells into resident memory T cells and provides a means to expand these cells in vitro, thereby affording an avenue to generate more effective tissue-specific immunotherapies.

The extracellular matrix protein fibronectin promotes metanephric kidney development.

Complex interactions of the branching ureteric bud (UB) and surrounding mesenchymal cells during metanephric kidney development determine the final number of nephrons. Impaired nephron endowment predisposes to arterial hypertension and chronic kidney disease. In the kidney, extracellular matrix (ECM) proteins are usually regarded as acellular scaffolds or as the common histological end-point of chronic kidney diseases. Since only little is known about their physiological role in kidney development, we aimed for analyzing the expression and role of fibronectin. In mouse, fibronectin was expressed during all stages of kidney development with significant changes over time. At embryonic day (E) 12.5 and E13.5, fibronectin lined the UB epithelium, which became less pronounced at E16.5 and then switched to a glomerular expression in the postnatal and adult kidneys. Similar results were obtained in human kidneys. Deletion of fibronectin at E13.5 in cultured metanephric mouse kidneys resulted in reduced kidney sizes and impaired glomerulogenesis following reduced cell proliferation and branching of the UB epithelium. Fibronectin colocalized with alpha 8 integrin and fibronectin loss caused a reduction in alpha 8 integrin expression, release of glial-derived neurotrophic factor and expression of Wnt11, both of which are promoters of UB branching. In conclusion, the ECM protein fibronectin acts as a regulator of kidney development and is a determinant of the final nephron number.