A comparison between full-length 16S rRNA Oxford nanopore sequencing and Illumina V3-V4 16S rRNA sequencing in head and neck cancer tissues.

Describing the microbial community within the tumour has been a key aspect in understanding the pathophysiology of the tumour microenvironment. In head and neck cancer (HNC), most studies on tissue samples have only performed 16S rRNA short-read sequencing (SRS) on V3-V5 region. SRS is mostly limited to genus level identification. In this study, we compared full-length 16S rRNA long-read sequencing (FL-ONT) from Oxford Nanopore Technology (ONT) to V3-V4 Illumina SRS (V3V4-Illumina) in 26 HNC tumour tissues. Further validation was also performed using culture-based methods in 16 bacterial isolates obtained from 4 patients using MALDI-TOF MS. We observed similar alpha diversity indexes between FL-ONT and V3V4-Illumina. However, beta-diversity was significantly different between techniques (PERMANOVA - R2 = 0.131, p < 0.0001). At higher taxonomic levels (Phylum to Family), all metrics were more similar among sequencing techniques, while lower taxonomy displayed more discrepancies. At higher taxonomic levels, correlation in relative abundance from FL-ONT and V3V4-Illumina were higher, while this correlation decreased at lower levels. Finally, FL-ONT was able to identify more isolates at the species level that were identified using MALDI-TOF MS (75% vs. 18.8%). FL-ONT was able to identify lower taxonomic levels at a better resolution as compared to V3V4-Illumina 16S rRNA sequencing.

S. aureus biofilm properties correlate with immune B cell subset frequencies and severity of chronic rhinosinusitis.

Staphylococcus aureus mucosal biofilms are associated with recalcitrant chronic rhinosinusitis (CRS). However, S. aureus colonisation of sinus mucosa is frequent in the absence of mucosal inflammation. This questions the relevance of S. aureus biofilms in CRS etiopathogenesis. This study aimed to investigate whether strain-level variation in in vitro-grown S. aureus biofilm properties relates to CRS disease severity, in vitro toxicity, and immune B cell responses in sinonasal tissue from CRS patients and non-CRS controls. S. aureus clinical isolates, tissue samples, and matched clinical datasets were collected from CRS patients with nasal polyps (CRSwNP), CRS without nasal polyps (CRSsNP), and controls. B cell responses in tissue samples were characterised by FACS. S. aureus biofilms were established in vitro, followed by measuring their properties of metabolic activity, biomass, colony-forming units, and exoprotein production. S. aureus virulence was evaluated using whole-genome sequencing, mass spectrometry and application of S. aureus biofilm exoproteins to air-liquid interface cultures of primary human nasal epithelial cells (HNEC-ALI). In vitro S. aureus biofilm properties were correlated with increased CRS severity scores, infiltration of antibody-secreting cells and loss of regulatory B cells in tissue samples. Biofilm exoproteins from S. aureus with high biofilm metabolic activity had enriched virulence genes and proteins, and negatively affected the barrier function of HNEC-ALI cultures. These findings support the notion of strain-level variation in S. aureus biofilms to be critical in the pathophysiology of CRS.

Staphylococcus aureus Biofilm-Secreted Factors Cause Mucosal Damage, Mast Cell Infiltration, and Goblet Cell Hyperplasia in a Rat Rhinosinusitis Model.

Chronic rhinosinusitis (CRS) is an inflammatory condition of the sinonasal mucosa. Despite being a common health issue, the exact cause of CRS is yet to be understood. However, research suggests that Staphylococcus aureus, particularly in its biofilm form, is associated with the disease. This study aimed to investigate the impact of long-term exposure to secreted factors of Staphylococcus aureus biofilm (SABSFs), harvested from clinical isolates of non-CRS carrier and CRS patients, on the nasal mucosa in a rat model. Animals were randomised (n = 5/group) to receive daily intranasal instillations of 40 µL (200 µg/µL) SABSFs for 28 days or vehicle control. The sinonasal samples were analysed through histopathology and transcriptome profiling. The results showed that all three intervention groups displayed significant lymphocytic infiltration (p ≤ 0.05). However, only the SABSFs collected from the CRSwNP patient caused significant mucosal damage, mast cell infiltration, and goblet cell hyperplasia compared to the control. The transcriptomics results indicated that SABSFs significantly enriched multiple inflammatory pathways and showed distinct transcriptional expression differences between the control group and the SABSFs collected from CRS patients (p ≤ 0.05). Additionally, the SABSF challenges induced the expression of IgA and IgG but not IgE. This in vivo study indicates that long-term exposure to SABSFs leads to an inflammatory response in the nasal mucosa with increased severity for S. aureus isolated from a CRSwNP patient. Moreover, exposure to SABSFs does not induce local production of IgE.

Use of tryptic peptide MALDI mass spectrometry imaging to identify the spatial proteomic landscape of colorectal cancer liver metastases.

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. CRC liver metastases (CRLM) are often resistant to conventional treatments, with high rates of recurrence. Therefore, it is crucial to identify biomarkers for CRLM patients that predict cancer progression. This study utilised matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to spatially map the CRLM tumour proteome. CRLM tissue microarrays (TMAs) of 84 patients were analysed using tryptic peptide MALDI-MSI to spatially monitor peptide abundances across CRLM tissues. Abundance of peptides was compared between tumour vs stroma, male vs female and across three groups of patients based on overall survival (0-3 years, 4-6 years, and 7+ years). Peptides were then characterised and matched using LC-MS/MS. A total of 471 potential peptides were identified by MALDI-MSI. Our results show that two unidentified m/z values (1589.876 and 1092.727) had significantly higher intensities in tumours compared to stroma. Ten m/z values were identified to have correlation with biological sex. Survival analysis identified three peptides (Histone H4, Haemoglobin subunit alpha, and Inosine-5'-monophosphate dehydrogenase 2) and two unidentified m/z values (1305.840 and 1661.060) that were significantly higher in patients with shorter survival (0-3 years relative to 4-6 years and 7+ years). This is the first study using MALDI-MSI, combined with LC-MS/MS, on a large cohort of CRLM patients to identify the spatial proteome in this malignancy. Further, we identify several protein candidates that may be suitable for drug targeting or for future prognostic biomarker development.

Identification of consensus head and neck cancer-associated microbiota signatures: a systematic review and meta-analysis of 16S rRNA and The Cancer Microbiome Atlas datasets.

Introduction. Multiple reports have attempted to describe the tumour microbiota in head and neck cancer (HNSC).Gap statement. However, these have failed to produce a consistent microbiota signature, which may undermine understanding the importance of bacterial-mediated effects in HNSC.Aim. The aim of this study is to consolidate these datasets and identify a consensus microbiota signature in HNSC.Methodology. We analysed 12 published HNSC 16S rRNA microbial datasets collected from cancer, cancer-adjacent and non-cancer tissues to generate a consensus microbiota signature. These signatures were then validated using The Cancer Microbiome Atlas (TCMA) database and correlated with the tumour microenvironment phenotypes and patient's clinical outcome.Results. We identified a consensus microbial signature at the genus level to differentiate between HNSC sample types, with cancer and cancer-adjacent tissues sharing more similarity than non-cancer tissues. Univariate analysis on 16S rRNA datasets identified significant differences in the abundance of 34 bacterial genera among the tissue types. Paired cancer and cancer-adjacent tissue analyses in 16S rRNA and TCMA datasets identified increased abundance in Fusobacterium in cancer tissues and decreased abundance of Atopobium, Rothia and Actinomyces in cancer-adjacent tissues. Furthermore, these bacteria were associated with different tumour microenvironment phenotypes. Notably, high Fusobacterium signature was associated with high neutrophil (r=0.37, P<0.0001), angiogenesis (r=0.38, P<0.0001) and granulocyte signatures (r=0.38, P<0.0001) and better overall patient survival [continuous: HR 0.8482, 95 % confidence interval (CI) 0.7758-0.9273, P=0.0003].Conclusion. Our meta-analysis demonstrates a consensus microbiota signature for HNSC, highlighting its potential importance in this disease.

Generation and assessment of cytokine-induced killer cells for the treatment of colorectal cancer liver metastases.

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. Cytokine-induced killer (CIK) cells are an adoptive immunotherapy reported to have strong anti-tumour activity across a range of cancers. They are a heterogeneous mix of lymphoid cells generated by culturing human peripheral blood mononuclear cells with cytokines and monoclonal antibodies in vitro. In this study, we investigated the yield and function of CIK cells generated from patients with CRC liver metastases. We first showed that CIK cells generated in serum free medium X-VIVO 15 were comparable to those from RPMI medium with 10% FBS in terms of the number and percentages of the main subsets of cells in the CIK culture, and the intracellular levels of granzyme B and perforin, and the pro-inflammatory cytokines IL-2, IFN-γ and TNF-α. The CIK cells were cytotoxic to CRC cell lines grown in 2D cultures or as spheroids, and against autologous patient-derived tumour organoids. Donor attributes such as age, sex, or prior chemotherapy exposure had no significant impact on CIK cell numbers or function. These results suggest that functional CIK cells can be generated from patients with CRC liver metastatic disease, and support further investigations into the therapeutic application of autologous CIK cells in the management of patients with CRC liver metastases.

Cytokine-induced killer (CIK) cells, successes and challenges: report on the first international conference dedicated to the clinical translation of this unique adoptive cell immunotherapy.

On August 30, 2023, experts from Germany and abroad met to discuss the successes and challenges of cytokine-induced killer cell (CIK) therapy, that recently celebrated its 30th anniversary providing treatment for cancer. This first virtual conference was hosted by CIO Bonn, a certified Comprehensive Cancer Center (CCC) funded by German Cancer Aid (DKH). In addition to keynote speakers involved in CIK cell clinical trials or optimized preclinical models to improve this adoptive cell immunotherapy, more than 100 attendees from around the world also participated in this event. Initiatives to establish the International Society of CIK Cells (ISCC) and a stronger CIK cell network guiding preclinical research and future clinical trials were also announced.

Clinical application of cytokine-induced killer (CIK) cell therapy in colorectal cancer: Current strategies and future challenges.

Colorectal cancer (CRC) remains a significant global health burden and is the second leading cause of cancer-related death. Cytokine induced killer (CIK) cell therapy is an immunotherapy which has the potential to meet this need. Clinical trials of CIK cell therapy for the management of CRC have reported improved clinical outcomes. However, production and delivery protocols varied significantly, and many studies were reported only in Chinese language journals. Here we present the most comprehensive review of the clinical CIK cell therapy trials for CRC management to date. We accessed both English and Chinese language clinical studies, and summarise how CIK cell therapy has been implemented, from manufacturing to patient delivery. We discuss current challenges that impede wider adoption of CIK cell therapy in CRC management.

Staging of colorectal cancer using lipid biomarkers and machine learning.

INTRODUCTION: Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. Alteration in lipid metabolism and chemokine expression are considered hallmark characteristics of malignant progression and metastasis of CRC. Validated diagnostic and prognostic biomarkers are urgently needed to define molecular heterogeneous CRC clinical stages and subtypes, as liver dominant metastasis has poor survival outcomes. OBJECTIVES: The aim of this study was to integrate lipid changes, concentrations of chemokines, such as platelet factor 4 and interleukin 8, and gene marker status measured in plasma samples, with clinical features from patients at different CRC stages or who had progressed to stage-IV colorectal liver metastasis (CLM). METHODS: High-resolution liquid chromatography-mass spectrometry (HR-LC-MS) was used to determine the levels of candidate lipid biomarkers in each CRC patient's preoperative plasma samples and combined with chemokine, gene and clinical data. Machine learning models were then trained using known clinical outcomes to select biomarker combinations that best classify CRC stage and group. RESULTS: Bayesian neural net and multilinear regression-machine learning identified candidate biomarkers that classify CRC (stages I-III), CLM patients and control subjects (cancer-free or patients with polyps/diverticulitis), showing that integrating specific lipid signatures and chemokines (platelet factor-4 and interluken-8; IL-8) can improve prognostic accuracy. Gene marker status could contribute to disease prediction, but requires ubiquitous testing in clinical cohorts. CONCLUSION: Our findings demonstrate that correlating multiple disease related features with lipid changes could improve CRC prognosis. The identified signatures could be used as reference biomarkers to predict CRC prognosis and classify stages, and monitor therapeutic intervention.

Staphylococcus aureus biofilm properties and chronic rhinosinusitis severity scores correlate positively with total CD4+ T-cell frequencies and inversely with its Th1, Th17 and regulatory cell frequencies.

Chronic rhinosinusitis (CRS) represents chronic inflammation of the sinus mucosa characterised by dysfunction of the sinuses' natural defence mechanisms and induction of different inflammatory pathways ranging from a Th1 to a Th2 predominant polarisation. Recalcitrant CRS is associated with Staphylococcus aureus dominant mucosal biofilms; however, S. aureus colonisation of the sinonasal mucosa has also been observed in healthy individuals challenging the significance of S. aureus in CRS pathogenesis. We aimed to investigate the relationship between CRS key inflammatory markers, S. aureus biofilm properties/virulence genes and the severity of the disease. Tissue samples were collected during endoscopic sinus surgery from the ethmoid sinuses of CRS patients with (CRSwNP) and without (CRSsNP) nasal polyps and controls (n = 59). CD3+ T-cell subset frequencies and key inflammatory markers of CD4+ helper T cells were determined using FACS analysis. Sinonasal S. aureus clinical isolates were isolated (n = 26), sequenced and grown into biofilm in vitro, followed by determining their properties, including metabolic activity, biomass, colony-forming units and exoprotein production. Disease severity was assessed using Lund-Mackay radiologic scores, Lund-Kennedy endoscopic scores and SNOT22 quality of life scores. Our results showed that S. aureus biofilm properties and CRS severity scores correlated positively with total CD4+ T-cell frequencies but looking into CD4+ T-cell subsets showed an inverse correlation with Th1 and Th17 cell frequencies. CD4+ T-cell frequencies were higher in patients harbouring lukF.PV-positive S. aureus while its regulatory and Th17 cell subset frequencies were lower in patients carrying sea- and sarT/U-positive S. aureus. Recalcitrant CRS is characterised by increased S. aureus biofilm properties in relation to increased total CD4+ helper T-cell frequencies and reduced frequencies of its Th1, Th17 and regulatory T-cell subsets. These findings offer insights into the pathophysiology of CRS and could lead to the development of more targeted therapies.

Perhexiline: Old Drug, New Tricks? A Summary of Its Anti-Cancer Effects.

Cancer metabolic plasticity, including changes in fatty acid metabolism utilisation, is now widely appreciated as a key driver for cancer cell growth, survival and malignancy. Hence, cancer metabolic pathways have been the focus of much recent drug development. Perhexiline is a prophylactic antianginal drug known to act by inhibiting carnitine palmitoyltransferase 1 (CPT1) and 2 (CPT2), mitochondrial enzymes critical for fatty acid metabolism. In this review, we discuss the growing evidence that perhexiline has potent anti-cancer properties when tested as a monotherapy or in combination with traditional chemotherapeutics. We review the CPT1/2 dependent and independent mechanisms of its anti-cancer activities. Finally, we speculate on the clinical feasibility and utility of repurposing perhexiline as an anti-cancer agent, its limitations including known side effects and its potential added benefit of limiting cardiotoxicity induced by other chemotherapeutics.

Use of cytokine-induced killer cell therapy in patients with colorectal cancer: a systematic review and meta-analysis.

BACKGROUND: The number of clinical studies evaluating the benefit of cytokine-induced killer cell (CIK) therapy, an adoptive immunotherapy, for colorectal cancer (CRC) is increasing. In many of these trials, CIK therapy was coadministered with conventional cancer therapy. The aim of this review is to systematically assess the available literature, in which the majority were only in Chinese, on CIK therapy for the management of CRC using meta-analysis and to identify parameters associated with successful CIK therapy implementation. METHODS: Prospective and retrospective clinical studies which compared CIK therapy to non-CIK therapy in patients with CRC were searched for electronically on MEDLINE, Embase, China National Knowledge Infrastructure, and Wanfang Data databases. The clinical endpoints of overall survival (OS), progression-free survival (PFS), OS and PFS rates, overall response rate (ORR), and toxicity were meta-analyzed using HR and relative ratio (RR), and subgroup analyses were performed using chi-square (χ2) test and I-squared (I2) statistics for study design, disease stage, cotherapy type, and timing of administration. RESULTS: In total, 70 studies involving 6743 patients were analyzed. CIK therapy was favored over non-CIK therapy for OS (HR=0.59, 95% CI: 0.53 to 0.65), PFS (HR=0.55, 95% CI: 0.47 to 0.63), and ORR (RR=0.65, 95% CI: 0.57 to 0.74) without increasing toxicity (HR=0.59, 95% CI: 0.16 to 2.25). Subgroup analyses on OS and PFS by study design (randomized vs non-randomized study design), disease stage (Stage I-III vs Stage IV), cotreatment with dendritic cells (DCs) (CIK vs DC-CIK therapy), or timing of therapy administration (concurrent vs sequential with coadministered anticancer therapy) also showed that the clinical benefit of CIK therapy was robust in any subgroup analysis. Furthermore, cotreatment with DCs did not improve clinical outcomes over CIK therapy alone. CONCLUSION: Compared with standard therapy, patients who received additional CIK cell therapy had favorable outcomes without increased toxicity, warranting further investigation into CIK therapy for the treatment of CRC.

Proteomic characterisation of perhexiline treatment on THP-1 M1 macrophage differentiation.

Background: Dysregulated inflammation is important in the pathogenesis of many diseases including cancer, allergy, and autoimmunity. Macrophage activation and polarisation are commonly involved in the initiation, maintenance and resolution of inflammation. Perhexiline (PHX), an antianginal drug, has been suggested to modulate macrophage function, but the molecular effects of PHX on macrophages are unknown. In this study we investigated the effect of PHX treatment on macrophage activation and polarization and reveal the underlying proteomic changes induced. Methods: We used an established protocol to differentiate human THP-1 monocytes into M1 or M2 macrophages involving three distinct, sequential stages (priming, rest, and differentiation). We examined the effect of PHX treatment at each stage on the polarization into either M1 or M2 macrophages using flow cytometry, quantitative polymerase chain reaction (qPCR) and enzyme linked immunosorbent assay (ELISA). Quantitative changes in the proteome were investigated using data independent acquisition mass spectrometry (DIA MS). Results: PHX treatment promoted M1 macrophage polarization, including increased STAT1 and CCL2 expression and IL-1ß secretion. This effect occurred when PHX was added at the differentiation stage of the M1 cultures. Proteomic profiling of PHX treated M1 cultures identified changes in metabolic (fatty acid metabolism, cholesterol homeostasis and oxidative phosphorylation) and immune signalling (Receptor Tyrosine Kinase, Rho GTPase and interferon) pathways. Conclusion: This is the first study to report on the action of PHX on THP-1 macrophage polarization and the associated changes in the proteome of these cells.

Characterization of human nasal organoids from chronic rhinosinusitis patients.

Patient-derived organoids grown in three-dimensional cultures provide an excellent platform for phenotypic high-throughput screening and drug-response research. Organoid technology has been applied to study stem cell biology and various human pathologies. This study investigates the characteristics and cellular morphology of organoids derived from primary human nasal epithelial cells (HNECs) of chronic rhinosinusitis (CRS) patients. Nasal organoids were cultured up to 20 days and morphological, cell composition and functional parameters were measured by immunofluorescence, RT-qPCR, western blot and FACS analysis. The results showed that nasal organoids expressed the stem cell marker leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), and markers for apical junction genes, goblet cells and ciliated cells. Moreover, we were able to regrow and expand the nasal organoids well after freezing and thawing. This study provides an effective and feasible method for development of human nasal organoids, suitable for the phenotypic high-throughput screening and drug response research.

The Antianginal Drug Perhexiline Displays Cytotoxicity against Colorectal Cancer Cells In Vitro: A Potential for Drug Repurposing.

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. Perhexiline, a prophylactic anti-anginal drug, has been reported to have anti-tumour effects both in vitro and in vivo. Perhexiline as used clinically is a 50:50 racemic mixture ((R)-P) of (-) and (+) enantiomers. It is not known if the enantiomers differ in terms of their effects on cancer. In this study, we examined the cytotoxic capacity of perhexiline and its enantiomers ((-)-P and (+)-P) on CRC cell lines, grown as monolayers or spheroids, and patient-derived organoids. Treatment of CRC cell lines with (R)-P, (-)-P or (+)-P reduced cell viability, with IC50 values of ~4 µM. Treatment was associated with an increase in annexin V staining and caspase 3/7 activation, indicating apoptosis induction. Caspase 3/7 activation and loss of structural integrity were also observed in CRC cell lines grown as spheroids. Drug treatment at clinically relevant concentrations significantly reduced the viability of patient-derived CRC organoids. Given these in vitro findings, perhexiline, as a racemic mixture or its enantiomers, warrants further investigation as a repurposed drug for use in the management of CRC.

Combining the Anticancer and Immunomodulatory Effects of Astragalus and Shiitake as an Integrated Therapeutic Approach.

Astragalus root (Huang Qi) and Shiitake mushrooms (Lentinus edodes) are both considered medicinal foods and are frequently used in traditional Chinese medicine due to their anticancer and immunomodulating properties. Here, the scientific literatures describing evidence for the anticancer and immunogenic properties of Shiitake and Astragalus were reviewed. Based on our experimental data, the potential to develop medicinal food with combined bioactivities was assessed using Shiitake mushrooms grown over Astragalus beds in a proprietary manufacturing process, as a novel cancer prevention approach. Notably, our data suggest that this new manufacturing process can result in transfer and increased bioavailability of Astragalus polysaccharides with therapeutic potential into edible Shiitake. Further research efforts are required to validate the therapeutic potential of this new Hengshan Astragalus Shiitake medicinal food.

CXCR5+CD8+ T Cells Shape Antibody Responses In Vivo Following Protein Immunisation and Peripheral Viral Infection.

Crosstalk between T and B cells is crucial for generating high-affinity, class-switched antibody responses. The roles of CD4+ T cells in this process have been well-characterised. In contrast, regulation of antibody responses by CD8+ T cells is significantly less defined. CD8+ T cells are principally recognised for eliciting cytotoxic responses in peripheral tissues and forming protective memory. However, recent findings have identified a novel population of effector CD8+ T cells that co-opt a differentiation program characteristic of CD4+ T follicular helper (Tfh) cells, upregulate the chemokine receptor CXCR5 and localise to B cell follicles. While it has been shown that CXCR5+CD8+ T cells mediate the removal of viral reservoirs in the context of follicular-trophic viral infections and maintain the response to chronic insults by virtue of progenitor/stem-like properties, it is not known if CXCR5+CD8+ T cells arise during acute peripheral challenges in the absence of follicular infection and whether they influence B cell responses in vivo in these settings. Using the ovalbumin-specific T cell receptor transgenic (OT-I) system in an adoptive transfer-immunisation/infection model, this study demonstrates that CXCR5+CD8+ T cells arise in response to protein immunisation and peripheral viral infection, displaying a follicular-homing phenotype, expression of cell surface molecules associated with Tfh cells and limited cytotoxic potential. Furthermore, studies assessing the B cell response in the presence of OT-I or Cxcr5-/- OT-I cells revealed that CXCR5+CD8+ T cells shape the antibody response to protein immunisation and peripheral viral infection, promoting class switching to IgG2c in responding B cells. Overall, the results highlight a novel contribution of CD8+ T cells to antibody responses, expanding the functionality of the adaptive immune system.

Immunological Memory in Imiquimod-Induced Murine Model of Psoriasiform Dermatitis.

Psoriasis is a common chronic inflammatory skin condition manifested by T cell responses and characterized by preferential recurrence at previously inflamed sites upon withdrawal of treatment. The site-specific disease memory in psoriasis has been linked to CD8+CD103+ tissue-resident memory T cells (Trm) in the epidermis which were previously thought to only provide "frontline" protection against pathogens and immunosurveillance during cancer development. In this study, we correlated the presence of a subset of the Trm cells which are also CD49a+ with disease severity in human psoriatic lesions with acute and chronic disease. Using an imiquimod (IMQ)-induced murine model of psoriasiform dermatitis, we also investigated the level of CD49a+ Trm cells in acute, chronic and resolved psoriatic lesions. Investigation of clinical human samples showed that patient disease severity highly correlated with the numbers of epidermal CD49a+ Trm cells. Additionally, this subset of Trm cells was shown to persist in resolved lesions of murine psoriasiform dermatitis once clinical disease features had subsided. Importantly, these CD49a+ Trm cells showed significantly higher levels of granzyme B (GzmB) production compared to acute disease, suggesting a potential role of CD49a+ Trm cells for psoriatic re-occurrence in resolved patients. Better understanding of epidermal CD49a+ Trm cell activity is necessary for development of advanced treatment strategies for psoriasis to permit long-term, continuous disease control.

ACKR4 restrains antitumor immunity by regulating CCL21.

Current immunotherapies involving CD8+ T cell responses show remarkable promise, but their efficacy in many solid tumors is limited, in part due to the low frequency of tumor-specific T cells in the tumor microenvironment (TME). Here, we identified a role for host atypical chemokine receptor 4 (ACKR4) in controlling intratumor T cell accumulation and activation. In the absence of ACKR4, an increase in intratumor CD8+ T cells inhibited tumor growth, and nonhematopoietic ACKR4 expression was critical. We show that ACKR4 inhibited CD103+ dendritic cell retention in tumors through regulation of the intratumor abundance of CCL21. In addition, preclinical studies indicate that ACKR4 and CCL21 are potential therapeutic targets to enhance responsiveness to immune checkpoint blockade or T cell costimulation.