CC Chemokine Receptor Research Articles

Helminth extracellular vesicles co-opt host monocytes to drive T cell anergy.

Parasitic helminths secrete extracellular vesicles (EVs) into their host tissues to modulate immune responses, but the underlying mechanisms are poorly understood. We demonstrate that Ascaris EVs are efficiently internalised by monocytes in human peripheral blood mononuclear cells and increase the percentage of classical monocytes. Furthermore, EV treatment of monocytes induced a novel anti-inflammatory phenotype characterised by CD14+, CD16-, CC chemokine receptor 2 (CCR2-) and programmed death-ligand 1 (PD-L1)+ cells. In addition, Ascaris EVs induced T cell anergy in a monocyte-dependent mechanism. Targeting professional phagocytes to induce both direct and indirect pathways of immune modulation presents a highly novel and efficient mechanism of EV-mediated host-parasite communication. Intra-peritoneal administration of EVs induced protection against gut inflammation in the dextran sodium sulphate model of colitis in mice. Ascaris EVs were shown to affect circulating immune cells and protect against gut inflammation; this highlights their potential as a subject for further investigation in inflammatory conditions driven by dysregulated immune responses. However, their clinical translation would require further studies and careful consideration of ethical implications.

Practical recommendations for therapy and monitoring of mogamulizumab patients in Germany.

Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common subtypes of the heterogeneous group of cutaneous T-cell lymphomas (CTCL). With the expansion of the biologic treatment landscape, new treatment options have become available in recent years, most notably the C-C chemokine receptor 4 (CCR4)-directed monoclonal antibody mogamulizumab. Based on the phaseIII pivotal trial, mogamulizumab is recommended by the German S2kguidelines for the second-line treatment of stageIB and above SS and MF, after at least one prior systemic therapy. Since then, new insights on safety and efficacy of mogamulizumab were generated by post hoc analyses and real-world evidence. A panel of CTCL-experts discussed available literature and own experiences and developed relevant recommendations on the use of mogamulizumab in clinical practice in Germany. The recommendations cover patient criteria, prior therapies, use of mogamulizumab as monotherapy or combination therapy, management of side effects, duration of therapy, and monitoring schedules. The aim of these clinical recommendations is to support healthcare professionals in their decision-making and use of mogamulizumab in daily practice.

Establishment of a high-affinity anti-mouse CXCR5 monoclonal antibody for flow cytometry

The CXC chemokine receptor 5 (CXCR5) is a member of the G protein-coupled receptor family that is highly expressed in B cells and a subset of T cells, such as T follicular helper cells. Various types of cancers, including non-small cell lung cancer, breast cancer, and prostate cancer, also express CXCR5. Therefore, antibodies that specifically bind to CXCR5 could be useful for clarification of the mechanisms of cancer progression. In this study, we aimed to develop high-affinity monoclonal antibodies targeting mouse CXCR5 (mCXCR5) for flow cytometry. The established anti-mCXCR5 mAb (Cx5Mab-3; rat IgG2b, kappa), demonstrated reactivity with mCXCR5-overexpressed Chinese hamster ovary (CHO)-K1 (CHO/mCXCR5) in flow cytometry. Kinetic analyses using flow cytometry indicated that the dissociation constants (KD) of Cx5Mab-3 for CHO/mCXCR5 cell is 7.2 × 10−10 M. Furthermore, Cx5Mab-3 did not cross-react with other mouse CC, CXC, CX3C, and XC chemokine receptors. These results indicate that Cx5Mab-3 is useful for detecting mCXCR5 in flow cytometry with high affinity and specificity.

Inflammation switches the chemoattractant requirements for naive lymphocyte entry into lymph nodes.

Sustained lymphocyte migration from blood into lymph nodes (LNs) is important for immune responses. The CC-chemokine receptor-7 (CCR7) ligand CCL21 is required for LN entry but is downregulated during inflammation, and it has been unclear how recruitment is maintained. Here, we show that the oxysterol biosynthetic enzyme cholesterol-25-hydroxylase (Ch25h) is upregulated in LN high endothelial venules during viral infection. Lymphocytes become dependent on oxysterols, generated through a transcellular endothelial-fibroblast metabolic pathway, and the receptor EBI2 for inflamed LN entry. Additionally, Langerhans cells are an oxysterol source. Ch25h is also expressed in inflamed peripheral endothelium, and EBI2 mediates B cell recruitment in a tumor model. Finally, we demonstrate that LN CCL19 is critical in lymphocyte recruitment during inflammation. Thus, our work explains how naive precursor trafficking is sustained in responding LNs, identifies a role for oxysterols in cell recruitment into inflamed tissues, and establishes a logic for the CCR7 two-ligand system.

Biomimetic Dendritic Cell-Based Nanovaccines for Reprogramming the Immune Microenvironment to Boost Tumor Immunotherapy.

Although dendritic cell (DC)-mediated immunotherapies are effective options for immunotherapy, traditional DC vaccines are hampered by a variety of drawbacks such as insufficient antigen delivery, weak lymph node homing, and the risk of living cell transfusion. To address the above-mentioned issues, we developed a personalized DC-mimicking nanovaccine (HybridDC) that enhances antigen presentation and elicits effective antitumor immunity. The biomimetic nanovaccine contains cell membranes derived from genetically engineered DCs, and several cellular components are simultaneously anchored onto these membranes, including CC-chemokine receptor 7 (CCR7), tumor-associated antigenic (TAA) peptide/tumor-derived exosome (TEX), and relevant costimulatory molecules. Compared with previous vaccines, the HybridDC vaccine showed an increased ability to target lymphoid tissues and reshape the immune landscape in the tumor milieu. HybridDC demonstrated significant therapeutic and prophylactic efficacy in poorly immunogenic, orthotopic models of glioma. Furthermore, the HybridDC vaccine potentiates the therapeutic efficacy of immune checkpoint blockade (ICB) therapy, providing a potential combination strategy to maximize the efficacy of ICB. Specifically, HybridDC can induce long-term protective immunity in memory T cells. Overall, the HybridDC vaccine is a promising platform for personalized cancer vaccines and may offer a combinational modality to improve current immunotherapy.

Chuanxiong Qingnao Granules (CQG) alleviates nitroglycerin-induced migraine-like pain in rats by glycerophospholipid metabolism and PI3K/Akt signaling pathway.

Chuanxiong Qingnao Granles (CQG), has been used to treat migraine headache (MH) for many years. However, current investigation of CQG have primarily focused on clinical studies, and the potential mechanisms underlying of its effects on MH have not been fully elucidated. In the present study, we applied an integrated approach of transcriptomics and metabolomics to elucidate the therapeutic mechanisms of CQG in nitroglycerin (NTG)-induced MH injury. Fifty rats were allocated into five random groups: control (Con), NTG, flunarizine (NTG + Flu) group, and two CQG groups (NTG + CQG-L and NTG + CQG-H). CQG notably reduced the duration of ear redness and the frequency of head scratching frequency in rats. It also lowered the levels of 5-hydroxytryptamine (5-HT), endothelin-1 (ET-1), calcitonin gene-related peptide type 1 receptor (CGPR1), and tumor necrosis factor alpha (TNF-α) and enhanced neuronal morphology following NTG-induced MH damage. Transcriptomic and metabolomic analyses pinpointed interleukin (IL)-17A, IL-13, and CC chemokine receptor type 3 (CCR3) as central CQG targets, glycerophospholipid metabolism as key metabolic pathway, and further experiments confirmed that CQG reduced the expression of IL-17A, IL-13, CCR3, and inhibited the expression of inflammatory cytokines by suppressing PI3K/Akt signaling pathway and glycerophospholipid metabolism, to attenuate neuroinflammation in MH rats. Taken together, CQG inhibited PI3K/Akt signaling pathway to reduced neuroinflammation, and modulated metabolic pathway of glycerophospholipid metabolism in MH. The findings of this study offer novel insights into the mechanisms underlying the therapeutic effects of CQG, highlighting its potential clinical application in treatment of MH.

Identification and interaction mechanism of novel small molecule antagonists targeting CC chemokine receptor 1/3/5 for treatment of non-small cell lung cancer.

Non-Small Cell Lung Cancer (NSCLC) was one of the most prevalent forms of lung cancer. Due to its ease of invasion and migration, the five-year survival rate was relatively low. Therefore, new strategies for NSCLC treatment were needed. CC chemokine receptor 1/3/5 (CCR1/CCR3/CCR5), a member of the G-protein coupled receptor family, could promote the migration and invasion of NSCLC cells by binding to related chemokines. Consequently, targeting CCR1, CCR3 and CCR5 might prevent the progression of the disease. So far, no compound had been reported as a common antagonist for CCR1, CCR3, and CCR5. In this research, we utilized virtual screening and structural optimization to obtain compound 5, which effectively inhibited the migration and invasion of NSCLC cells. Meanwhile, Western Blot and Enzyme linked immunosorbent assay (ELISA) manifested that compound 5 suppressed migration and invasion of NSCLC cells by suppressing the nuclear factor κB (NF-κB) and the consequently decreased Matrix Metalloproteinase-9(MMP-9) secretion. Moreover, drug affinity responsive target stability (DARTS) experiment and molecular simulations confirmed that compound 5 was capable of binding with CCR1/CCR3/CCR5, and Van der Waals forces were instrumental in the binding process. Ile91, Tyr113, Gln284, and Ser184(CCR1-ligand5), Ile189, Met213, and Leu209(CCR3-ligand5), Phe109, Gln194, and Thr195(CCR5-ligand5) had Van der Waals interactions with ligand 5. Dynamic cross-correlation matrix (DCCM) and free energy landscape (FEL) showed that compound 5 could stably bind to CCR1/CCR3/CCR5 to change conformation of the protein and the tendency of residue movements, leading to a persistent inhibitory effect. This study aimed to provide assistance in the rational design of common antagonists for CCR1, CCR3, and CCR5.

Tertiary Lymphoid Structure in Dental Pulp: The Role in Combating Bacterial Infections.

Tertiary lymphoid structure (TLS) is associated with various pathologies, including those of cancers and chronic infections. Depending on the organ, multiple factors regulate the formation of TLS. However, the role of TLS in immune response and the molecules that drive its formation remain uncertain. The dental pulp, includes a few immune cells surrounded by rigid mineralized tissue, and opens to the outside through the apical foramen. Owing to this special organization, the dental pulp generates a directional immune response to bacterial infection. Considering this aspect, the dental pulp is an ideal model for comprehensively studying the TLS. In the present study, single-cell RNA sequencing of healthy and inflamed human dental pulp reveals known markers of TLS, including C-C motif chemokine ligand 19 (CCL19), lysosome-associated membrane glycoprotein 3 (LAMP3), CC chemokine receptor 7 (CCR7), and CD86, present in inflamed dental pulp. Compared with the healthy pulp, types and proportions of immune cells increase, along with enhanced cellular communication. Multiple immunofluorescence staining reveals that typical TLS emerges in dental pulp with pulpitis, consistent with the high expression of CC chemokine ligand 3 (CCL3), which may be a key driver of TLS formation. Moreover, TLS is also observed in a mouse model of pulpitis. These findings collectively offer insights into the formation and function of TLS in response to infection.

Chemokine CCL2 and its receptor CCR2 in different age groups of patients with COVID-19

BackgroundDespite the development of various antiviral drugs, most of them are not effective in the treatment of coronavirus disease 2019 (COVID-19) as a hyperinflammatory disorder. Chemokine (C-C motif) ligand 2 (CCL2) is one of the critical CC chemokines involved in the pathogenesis and severity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. This study aimed to investigate the expression of CCL2 and CC chemokine receptor 2 (CCR2) in COVID-19 patients.MethodsPeripheral blood samples were collected from 60 confirmed COVID-19 patients and 60 age-matched healthy subjects. The ages of the subjects were categorized as follows: up to 20 years, 20 to 40 years, 40 to 60 years, and more than 60 years. CCL2 serum levels were measured using the enzyme-linked immunosorbent assay (ELISA). CCR2 gene expression in peripheral blood mononuclear cells (PBMCs) was measured employing real-time polymerase chain reaction (PCR).ResultsIn all age groups, CCL2 serum levels were significantly elevated in patients compared to healthy controls (P < 0.0001). CCL2 levels were higher in severe patients than in moderate patients. Moreover, CCR2 expression by PBMCs was higher in patients compared to control subjects. However, a significant difference between patients and controls over 60 years of age was identified (P = 0.0353). There was no significant difference in CCR2 expression between moderate and severe COVID-19 patients.ConclusionsTaken together, the findings demonstrate that CCL2 and CCR2 are upregulated in COVID-19 patients at protein and mRNA levels, respectively. Therefore, the CCL2/CCR2 axis may be a potential therapeutic target in order to improve patient outcomes.

Characterization, expressional and evolutionary analysis of five fish-specific CCRs (CCR4La, CCR4Lc, CCR12a1, CCR12a2, and CCR12b) in largemouth bass (Micropterus salmoides)

CC chemokine receptors (CCRs), the numbers of the G protein-coupled receptor (GPCR) superfamily, had crucial roles in treating infection, inflammation, and tissue damage by binding to their ligands. In this study, five fish-specific CCRs, namely CCR4La, CCR4Lc, CCR12a1, CCR12a2, and CCR12b, were identified in largemouth bass (Micropterus salmoides). The correction of nomenclatures of these CCRs were confirmed by phylogenetic analysis, structural analysis and genomic synteny analysis. Following 1 × 106 CFU/mL and 1 × 107 CFU/mL Edwardsiella piscicida infection, these five CCRs were significantly induced in spleen of largemouth bass, indicating their important roles in the immune response against bacterial infection. Selection pressure analysis revealed that CCR4La, CCR4Lc, CCR12a1, and CCR12a2 underwent negative selection pressure, whereas CCR12b experienced positive selection pressure. Robust selection site detection methods identified that positive selected sites of CCR4La, CCR4Lc, CCR12a1, and CCR12a2 mainly distributed in their extracellular regions, which involved in ligand binding and pathogen interaction. Similarly, the positive selected sites of CCR12b were also located in its extracellular regions. The accuracy of the pressure selected sites were also validated by molecular docking analysis. The potential ligands for these five CCRs were identified by molecular docking analysis, with finding that CCL3 and CCL5 might be the ligands of largemouth bass CCR4La/Lc, and CCL5, CCL8, CCL7, CCL13 and CCL26 might be that of largemouth bass CCR12a1/a2/b. Our results provided basis for elucidating the functions of chemokine-receptor complex in largemouth bass.

Impact of CCR5Δ32 on the risk of infection, Staphylococcus aureus carriage, and plasma concentrations of chemokines in Danish blood donors

The CC chemokine receptor 5 (CCR5) is a suggested receptor for Staphylococcus aureus leukotoxin ED. Homozygosity for the Δ32 deletion (CCR5Δ32) protects against human immunodeficiency virus infection and possibly also against leukotoxin ED. We examined the impact of CCR5Δ32 on the susceptibility to S.aureus infection, all-cause infections, and S.aureus nasal carriage, respectively, and on the concentrations of circulating chemokines in blood donors. We included 95,406 participants from the Danish Blood Donor Study (DBDS) genotyped for >650,000 single nucleotide polymorphisms. The CCR5Δ32 (rs333, MAF: 0.12) was imputed from a reference panel and validated. Infectious outcomes were identified by diagnosis codes and redeemed prescription of antibiotics in national health registers. Data on S.aureus nasal carriage and forty-seven inflammatory biomarkers were available for 6721 and 7811 participants, respectively. Cox, logistic, and linear regression models adjusted for relevant confounders were used to explore said associations. During more than 700,000 person-years of observation, we found that CCR5Δ32 was associated with neither an increased risk of redeemed dicloxacillin, hospital-treated S.aureus-associated infection (replicated in 345,996 Icelanders), redeemed antibiotics, all-cause infection, and nor with S.aureus nasal carriage. We discovered an association between CCR5Δ32 and elevated CCL4 concentrations, which were 1.26-fold higher in Δ32-heterozygotes (95%-CI: 1.23-1.30) and 2.64-fold higher in Δ32-homozygotes (95%-CI: 2.41-2.90) compared with wildtype homozygotes. Conversely, concentrations of CCL2, CXCL-10, and CCL11 were slightly lower among Δ32-heterozygotes. Results from this CCR5Δ32 high-prevalent cohort do not support the idea that CCR5Δ32 affects the risk of S.aureus carriage or infection to any relevant degree, in this northern European context. CCL4 was the main chemokine affected by CCR5Δ32 and was observed in higher concentration among Δ32-carriers. This study cannot rule out that S.aureus is a previous driver of CCR5Δ32 selection. The Health Research Fund of Central Denmark Region, Aarhus University, Danish Administrative Regions, Bio- and Genome Bank Denmark, Danish Blood Donor Research Foundation, Aase & Ejnar Danielsens Foundation, Højmosegård Grant, National Institute of Allergy and Infectious Diseases, and A.P. Møller Foundation for the Advancement of Medical Science.

Osteopontin Promotes Cholangiocyte Secretion of Chemokines to Support Macrophage Recruitment and Fibrosis in MASH.

Osteopontin (OPN) promotes the ductular reaction and is a major driver of chronic liver disease (CLD) progression. Although CLD is characterised by the accumulation of inflammatory cells including macrophages around the peri-portal regions, the influence of OPN on recruitment is unclear. We investigated the role of OPN in cholangiocyte chemokine production and macrophage recruitment by combining invivo, invitro, and in silico approaches. The effects of OPN on cholangiocyte chemokine production and macrophage migration were assessed in culture, alongside RNA-sequencing to identify genes and pathways affected by OPN depletion. Murine liver injury models were used to assess liver chemokine expression and liver macrophage/monocyte recruitment. OPN and chemokine expression were analysed in liver tissue and plasma from biopsy-proven metabolic dysfunction-associated alcoholic steatohepatitis (MASH) patients. OPN-knockdown in cholangiocytes reduced chemokine secretion. RNA-sequencing showed OPN-related effects clustered around immunity, chemotaxis and chemokine production. Macrophage exposure to cholangiocyte-conditioned media showed OPN-supported migration via chemokines chemokine (C-C motif) ligand (CCL)2, CCL5 and chemokine (C-X-C motif) ligand (CXCL)1. These effects were related to NF-κB signalling. Murine liver fibrosis was accompanied by upregulated liver OPN, CCL2, CCL5 and CXCL1 mRNA, and accumulation of liver cluster of differentiation (CD)11b/F4/80+CC chemokine receptors (CCR2)high macrophages but treatment with OPN-specific neutralising aptamers reduced fibrosis, chemokine mRNAs and accumulation of liver CD11b/F4/80+CCR2high/lymphocyte antigen 6 complexhigh inflammatory monocytes. In human MASH, liver OPN correlated with chemokines CCL2 and IL8 in association with portal injury and fibrosis. Plasma OPN, serum CCL2 and IL8 also increased with fibrosis stage. OPN promotes cholangiocyte chemokine secretion and the accumulation of pro-inflammatory monocytes. These data support neutralisation of OPN as an anti-inflammatory and anti-fibrotic strategy.

SATB1 prevents immune cell infiltration by regulating chromatin organization and gene expression of a chemokine gene cluster in T cells

SATB1, a key regulator of T cell development, governs lineage-specific transcriptional programs upon T cell activation. The absence of SATB1 has been linked to the initiation and progression of autoimmunity. However, its precise roles in this process remain incompletely understood. Here we show that conditional knockout of Satb1 in CD4+ T cells in mice led to T cell hyperactivation and inflammatory cell infiltration across multiple organs. Transcriptional profiling on activated T cells revealed that the loss of SATB1 led to aberrant upregulation of CC chemokines. Treating Satb1 conditional knockout mice with CC chemokine receptor inhibitor alleviated inflammatory cell infiltration. Intriguingly, SATB1’s transcriptional regulation of chemokine genes could not be attributed to its direct binding to chemokine promoters. Instead, SATB1 exerted its regulatory effects by controlling higher-order chromatin organization at a CC chemokine locus. The loss of SATB1 led to the emergence of a new chromatin domain encompassing the Ccl3, Ccl4, Ccl5, Ccl6, and Ccl9 genes and a distal enhancer, resulting in increased contacts between the enhancer and all five chemokine genes, thus inducing their upregulation. Collectively, these results demonstrate that SATB1 protects organs from immune cell infiltration by regulating chemokine expression, providing valuable insights into the development of autoimmunity-related phenotypes.

Plasma Interleukin-13 Levels Correlate With the Severity of Symptoms Induced by Functional Dyspepsia.

Functional dyspepsia (FD) is a gastrointestinal functional disorder of the upper gastrointestinal tract that affects the quality of life of patients and poses a significant economic burden. It has been proposed that the local inflammatory immune response at the duodenum is associated with an increase in intestinal permeability, favoring the recruitment of Th2 cells and granulocyte degranulation. Moreover, systemic immune response could also be related to the symptoms of FD. The objective of this study was to evaluate the systemic immune response in Uruguayan patients with FD by analyzing the cytokine levels in plasma and the frequency of circulating T cells associated with duodenal recruitment. An analytic and cross-sectional study in 30 patients with FD and 15 healthy controls (HCs) was carried out. Patients were diagnosed with FD according to the Roma IV Committee definition. Cytokine levels were measured in plasma by a specific assay. Expression of α4β7 and CC chemokine receptor9 in circulating T cells was evaluated by flow cytometry. Higher levels of interleukin (IL)-5, IL-13, and IL-8 and lower levels of IL-10 and IL-12p70 were detected in patients with FD than in HC. Furthermore, a positive linear correlation between IL-13 and the severity of FD symptoms was found. CD4 + T cells from patients with FD expressed higher levels of α4β7 and CC chemokine receptor9 than those from HC. An increase of Th2-like cytokines and a positive correlation between the levels of plasma IL-13 and the severity of symptoms in patients with FD from Uruguay were detected.

Utility of CCR7 to differentiate classic Hodgkin lymphoma and other B-cell lymphomas by flow cytometry and immunohistochemistry.

Classic Hodgkin lymphoma (CHL) is characterized by infrequent neoplastic Hodgkin and Reed-Sternberg (HRS) cells in an inflammatory background. The diagnostic utility of CC-chemokine receptor 7 (CCR7) in CHL was explored using flow cytometry and immunohistochemistry (IHC). Neoplastic specimens and non-neoplastic lymph nodes were immunophenotyped and CCR7 expression was measured semiquantitatively by flow cytometry (clone 3D12) and IHC (clone 150503). Our results showed that CCR7 was expressed on HRS cells in the vast majority of CHL cases (45/48 by flow cytometry, 57/59 by IHC) but rarely expressed in neoplastic cells in diffuse large B-cell lymphoma, not otherwise specified (1/25 by flow cytometry, 2/40 by IHC) and nodular lymphocyte predominant Hodgkin lymphoma (0/4 by flow cytometry, 1/13 by IHC). Primary mediastinal large B-cell lymphoma (PMLBCL) revealed weak CCR7 expression by flow cytometry in most cases (8/10) but only occasionally by IHC (2/12). Both cases (2/2) of T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) also showed CCR7 expression detected by flow cytometry compared with IHC (0/7). The HRS cells demonstrated a greater percentage of positive cells and greater antigen intensity than the other B-cell lymphomas by IHC. The expression identified by flow cytometry in PMLBCL and THRLBCL but not by IHC suggests that there may be differences in the detection capabilities of the 2 techniques or the2 CCR7 clones used. The expression of CCR7 in HRS cells suggests its potential utility in differentiating CHL from other B-cell lymphomas. Incorporating CCR7 into flow cytometry and IHC panels may further enhance the diagnostic sensitivity of CHL.

MIP3α-Rel Mtb intranasal DNA vaccination induces reactive T-cell infiltration into the lungs in mice and macaques.

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is the leading cause of mortality due to a single infectious organism. While generally curable, TB requires a lengthy and complex antibiotic regimen, due in large part to bacteria that can shift to a persistent state in the presence of antibiotic pressure. Rel Mtb is the primary enzyme regulating the stringent response, which contributes to the metabolic shift of Mtb to a persistent state. Targeting Rel Mtb with a vaccine to eliminate persistent bacteria through the induction of Rel Mtb -specific T-cell immunity in combination with antibiotics to kill dividing bacteria has shown promise in model systems. In a mouse model of Mtb infection, a vaccine created by genetically fusing rel Mtb to the chemokine macrophage inflammatory protein 3α ( MIP3 α), a ligand for the CC chemokine receptor type 6 (CCR6) present on immature dendritic cells, has been shown to enhance T-cell responses and accelerate eradication of infection in mouse models compared to a vaccine lacking the chemokine component. In this study, immunogenicity studies in the mouse and rhesus macaque models provide evidence that intranasal administrations of the DNA form of the MipRel vaccine led to enhanced lung infiltration of T cells after a series of immunizations. Furthermore, despite similar T-cell immunity seen in PBMCs between MipRel and Rel vaccinations, lung and bronchoalveolar lavage cell samples are more enriched for cytokine-secreting T cells in MipRel groups compared to Rel groups. We conclude that intranasal immunization with a MIP-3α fusion vaccine represents a novel strategy for use of a simple DNA vaccine formulation to elicit T-cell immune responses within the respiratory tract. That this formulation is immunogenic in a non-human primate model historically viewed as poorly responsive to DNA vaccines indicates the potential for clinical application in the treatment of Mtb infection, with possible application to other respiratory pathogens. Future studies will further characterize the protective effect of this vaccination platform.

C-C Chemokine Receptor 7 Promotes T-Cell Acute Lymphoblastic Leukemia Invasion of the Central Nervous System via β2-Integrins.

C-C Chemokine Receptor 7 (CCR7) mediates T-cell acute lymphoblastic leukemia (T-ALL) invasion of the central nervous system (CNS) mediated by chemotactic migration to C-C chemokine ligand 19 (CCL19). To determine if a CCL19 antagonist, CCL198-83, could inhibit CCR7-induced chemotaxis and signaling via CCL19 but not CCL21, we used transwell migration and Ca2+ mobilization signaling assays. We found that in response to CCL19, human T-ALL cells employ β2 integrins to invade human brain microvascular endothelial cell monolayers. In vivo, using an inducible mouse model of T-ALL, we found that we were able to increase the survival of the mice treated with CCL198-83 when compared to non-treated controls. Overall, our results describe a targetable cell surface receptor, CCR7, which can be inhibited to prevent β2-integrin-mediated T-ALL invasion of the CNS and potentially provides a platform for the pharmacological inhibition of T-ALL cell entry into the CNS.

Randomized, placebo-controlled study on the effects of intravenous GSK3858279 (anti-CCL17) on a battery of evoked pain tests in healthy participants.

C-C Motif Chemokine Ligand 17 (CCL17) is a chemokine that binds and signals through the G-protein coupled CC-chemokine receptor 4 and has been implicated in the development of inflammatory and arthritic pain. GSK3858279 is a high-affinity, first-in-class, monoclonal antibody, binding specifically to CCL17 and inhibiting downstream signaling. In this phase I, randomized, single-center, double-blind, placebo-controlled, three-period, incomplete-block crossover study (NCT04114656), the analgesic effects and safety of intravenous GSK3858279 were assessed in a battery of evoked acute pain assessments on healthy, adult (aged ≥18 years), male participants. Participants were randomized 1:1 to receive either one placebo (0.9% w/v NaCl) dose followed by two GSK3858279 doses (PAA treatment sequence), or one GSK3858279 dose followed by two placebo doses (APP treatment sequence). The co-primary end points were ultraviolet B heat pain detection threshold (°C), cold pressor time to pain tolerance threshold (PTT, sec), and electrical PTT (mA, single stimulus). Twenty-one participants were enrolled (PAA = 11; APP = 10). Mean age (standard deviation) was 29.3 (7.9) years for PAA, 31.1 (7.7) years for APP. No significant differences were observed in the analgesic effect between GSK3858279 and placebo for any end point. Exposure to GSK3858279 was similar between Period 1 (APP sequence), and Periods 2 and 3 (PAA sequence), with some GSK3858279 carry-over. Changes in serum CCL17 levels were consistent with the expected GSK3858279 activity. All drug-related adverse events were mild in intensity and caused no discontinuations. The absence of an efficacy signal in this acute pain model does not preclude efficacy in chronic pain states.

Structural basis for CCR6 modulation by allosteric antagonists

The CC chemokine receptor 6 (CCR6) is a potential target for chronic inflammatory diseases. Previously, we reported an active CCR6 structure in complex with its cognate chemokine CCL20, revealing the molecular basis of CCR6 activation. Here, we present two inactive CCR6 structures in ternary complexes with different allosteric antagonists, CCR6/SQA1/OXM1 and CCR6/SQA1/OXM2. The oxomorpholine analogues, OXM1 and OXM2 are highly selective CCR6 antagonists which bind to an extracellular pocket and disrupt the receptor activation network. An energetically favoured U-shaped conformation in solution that resembles the bound form is observed for the active analogues. SQA1 is a squaramide derivative with close-in analogues reported as antagonists of chemokine receptors including CCR6. SQA1 binds to an intracellular pocket which overlaps with the G protein site, stabilizing a closed pocket that is a hallmark of inactive GPCRs. Minimal communication between the two allosteric pockets is observed, in contrast to the prevalent allosteric cooperativity model of GPCRs. This work highlights the versatility of GPCR antagonism by small molecules, complementing previous knowledge of CCR6 activation, and sheds light on drug discovery targeting CCR6.

Crisaborole combined with vitamin D demonstrates superior therapeutic efficacy over either monotherapy in mice with allergic contact dermatitis

This study evaluated the therapeutic efficacy and underlying mechanisms of crisaborole combined with vitamin D in the treatment of allergic contact dermatitis. While crisaborole, a phosphodiesterase 4 inhibitor, and vitamin D analogs are commonly used in the treatment of atopic dermatitis, their combined therapeutic potential in allergic contact dermatitis (ACD) remains unexplored. Given their anti-inflammatory properties, we hypothesized that the combination of crisaborole and vitamin D could offer superior efficacy in mitigating the symptoms and underlying mechanisms of allergic contact dermatitis. In vitro, HaCaT cells stimulated with tumor necrosis factor-α and interferon-γ were treated with a combination of crisaborole and vitamin D, followed by cytokine expression analysis. In vivo, male C57BL/6 mice were divided into five groups and treated accordingly: blank control, dinitrochlorobenzene-induced model, crisaborole alone, vitamin D alone, and a combination of crisaborole and vitamin D. On day 14, dorsal skin and ear thickness were measured, followed by comprehensive pathological evaluations. In vivo and in vitro experiments showed that the expression levels of inflammatory factors were significantly lower in the DNCB + VD + Cri group than in the DNCB group. Histological analyses revealed that, compared with the DNCB group, the combined treatment group significantly reduced epidermal hyperkeratosis, improved epidermal transdermal water loss, decreased dermatitis scores, and diminished mast cell infiltration. Moreover, it lowered the expression levels of IL-6, IL-4, TNF-α, iNOS, IL-17, CC chemokine ligand 2 (CCL2), and CC chemokine receptor 2 (CCR2). CCL2 recognizes CCR2 and stimulates inflammatory cells, enhancing the inflammatory response. Increased CCL2 expression correlates with heightened inflammation and dendritic cell infiltration in ACD, while downregulation of CCL2 attenuates inflammation. Thus, the combined use of crisaborole and vitamin D demonstrates superior therapeutic efficacy over monotherapy in a mouse model of ACD. The combination of vitamin D and crisaborole significantly reduces inflammation and epidermal hyperkeratosis in a mouse model of allergic contact dermatitis, demonstrating superior therapeutic efficacy compared to either treatment alone. This suggests that the combined therapy could be a promising approach for the prevention and treatment of allergic contact dermatitis.