IL-17A production in human psoriatic blood and lesions by CD146+ T cells

Mass Spectrometry-Based Proteomics Analysis Unveils PTPRS Inhibits Proliferation and Inflammatory Response of Keratinocytes in Psoriasis

In this study, we used data-independent acquisition-mass spectrometry (DIA-MS) to analyze the serum proteome in psoriasis vulgaris (PsO). The serum proteomes of seven healthy controls and eight patients with PsO were analyzed using DIA-MS. Weighted gene co-expression network analysis was used to identify differentially expressed proteins (DEPs) that were closely related to PsO. Hub proteins of PsO were also identified. The Proteomics Drug Atlas 2023 was used to predict candidate hub protein drugs. To confirm the expression of the candidate factor, protein tyrosine phosphatase receptor S (PTPRS), in psoriatic lesions and the psoriatic keratinocyte model, immunohistochemical staining, quantitative real-time polymerase chain reaction, and western blotting were performed. A total of 129 DEPs were found to be closely related to PsO. The hub proteins for PsO were PVRL1, FGFR1, PTPRS, CDH2, CDH1, MCAM, and THY1. Five candidate hub protein drugs were identified: encorafenib, leupeptin, fedratinib, UNC 0631, and SCH 530348. PTPRS was identified as a common pharmacological target for these five drugs. PTPRS knockdown in keratinocytes promoted the proliferation and expression of IL-1α, IL-1β, IL-23A, TNF-α, MMP9, CXCL8, and S100A9. PTPRS expression was decreased in PsO, and PTPRS negatively regulated PsO. PTPRS may be involved in PsO pathogenesis through the inhibition of keratinocyte proliferation and inflammatory responses and is a potential treatment target for PsO.

MCAM+CD161- Th17 Subset Expressing CD83 Enhances Tc17 Response in Psoriasis

Recent studies have highlighted the pathogenic roles of IL-17-producing CD8+ T cells (T-cytotoxic 17 [Tc17]) in psoriasis. However, the underlying mechanisms of Tc17 induction remain unclear. In this study, we focused on the pathogenic subsets of Th17 and their mechanism of promotion of Tc17 responses. We determined that the pathogenic Th17-enriched fraction expressed melanoma cell adhesion molecule (MCAM) and CCR6, but not CD161, because this subset produced IL-17A abundantly and the presence of these cells in the peripheral blood of patients has been correlated with the severity of psoriasis. Intriguingly, the serial analysis of gene expression revealed that CCR6+MCAM+CD161-CD4+ T cells displayed the gene profile for adaptive immune responses, including CD83, which is an activator for CD8+ T cells. Coculture assay with or without intercellular contact between CD4+ and CD8+ T cells showed that CCR6+MCAM+CD161-CD4+ T cells induced the proliferation of CD8+ T cells in a CD83-dependent manner. However, the production of IL-17A by CD8+ T cells required exogenous IL-17A, suggesting that intercellular contact via CD83 and the production of IL-17A from activated CD4+ T cells elicit Tc17 responses. Intriguingly, the CD83 expression was enhanced in the presence of IL-15, and CD83+ cells stimulated with IL-1β, IL-23, IL-15, and IL-15Rα did not express FOXP3. Furthermore, CCR6+MCAM+CD161-CD4+ T cells expressing CD83 were increased in the peripheral blood of patients, and the CD83+ Th17-type cells accumulated in the lesional skin of psoriasis. In conclusion, pathogenic MCAM+CD161- Th17 cells may be involved in the Tc17 responses via IL-17A and CD83 in psoriasis.

Mediators of Capillary-to-Venule Conversion in the Chronic Inflammatory Skin Disease Psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by epidermal hyperplasia and hyperkeratosis, immune cell infiltration and vascular remodeling. Despite the emerging recognition of vascular normalization as a potential strategy for managing psoriasis, an in-depth delineation of the remodeled dermal vasculature has been missing. In this study, we exploited 5' single-cell RNA sequencing to investigate the transcriptomic alterations in different subpopulations of blood vascular and lymphatic endothelial cells directly isolated from psoriatic and healthy human skin. Individual subtypes of endothelial cells underwent specific molecular repatterning associated with cell adhesion and extracellular matrix organization. Blood capillaries, in particular, showed upregulation of the melanoma cell adhesion molecule as well as its binding partners and adopted postcapillary venule‒like characteristics during chronic inflammation that are more permissive to leukocyte transmigration. We also identified psoriasis-specific interactions between cis-regulatory enhancers and promoters for each endothelial cell subtype, revealing the dysregulated gene regulatory networks in psoriasis. Together, our results provide more insights into the specific transcriptional responses and epigenetic signatures of endothelial cells lining different vessel compartments in chronic skin inflammation.

Evaluation of cytokine gene expression in psoriasis

Introduction

Psoriasis is a chronic inflammatory disease affecting the skin with an unclear etiological significance.

Aim

In this study, we determined the mRNA expression and circulating levels of T helper (Th)/T regulatory (Treg) cytokines in psoriasis and analyzed their association with disease severity and treatment response.

Material and methods

189 psoriasis patients and 189 controls were recruited. Circulating Th/Treg cytokines (IL-12, IFN-γ, IL-17, IL-23, TGF-β and IL-4) were measured at baseline and at follow-up after 12 weeks of methotrexate treatment by ELISA and their relative mRNA expression at baseline was estimated by quantitative PCR.

Results

We observed increased levels of Th1/Th17 cytokines (IFN-γ, IL-17, IL-12 and IL-23) and a decrease in levels of Th2/Treg cytokines (IL-4 and TGF-β) in psoriasis patients at baseline, as compared to controls. Further, we observed that there was a significant decrease in Th1/Th17 cytokines, whilst Th2/Treg cytokine levels were significantly increased on follow-up after treatment with systemic metho trexate, as compared to pre-treatment levels. Our results were further confirmed by the significantly higher mRNA expression of Th1/Th17 cytokine genes and significantly lower mRNA expression of Th2/Treg cytokine genes in patients with psoriasis, as compared to controls. A significant positive correlation of Th1/Th17 cytokines was observed with disease severity in cases, whilst Th2/Treg cytokines correlated negatively with disease severity.

Conclusions

Our results show that increased Th1/Th17 cytokines and decreased Th2/Treg cytokines, both at the circulatory and gene expression level, play an important role in the immunopathogenesis and severity of psoriasis.

Phenotype and pathological significance of MCAM+ (CD146+) T cell subset in psoriatic arthritis

Background

CD146 (MCAM-melanoma cell adhesion molecule) is a cell surface adhesion molecule for Laminin 411. T cells expressing MCAM are mainly responsible for IL-17 production. IL-17 secreting T helper cells (Th17 cells) are critical for the pathogenesis of psoriatic arthritis (PsA). Here we hypothesized enrichment of CD146⁺IL-17⁺ memory T cells in PsA synovium and studied the association of CD146 expression and CD4⁺IL-17⁺ activated memory (CD11a⁺CD45RO⁺) T cells in synovial fluid and blood of PSA, rheumatoid arthritis (RA, a positive control) and osteoarthritis (OA) patients.

Methods

Hi-D FACS studies were done to identify IL-17 in CD4⁺CD146⁺CD45RO⁺ and CD8⁺CD146⁺CD45RO⁺ T cells.

Results

We observed that effector CD146⁺(MCAM⁺) T cells are enriched at the synovial inflammation site in PsA.

Conclusion

As CD146⁺ T cells are a key resource for IL-17 it is likely that the enrichment of these MCAM⁺ pathologic cells are critical for the disease process of PsA.

Role of CD146 (MCAM) in Physiological and Pathological Angiogenesis-Contribution of New Antibodies for Therapy

The fundamental role of cell adhesion molecules in mediating various biological processes as angiogenesis has been well-documented. CD146, an adhesion molecule of the immunoglobulin superfamily, and its soluble form, constitute major players in both physiological and pathological angiogenesis. A growing body of evidence shows soluble CD146 to be significantly elevated in the serum or interstitial fluid of patients with pathologies related to deregulated angiogenesis, as autoimmune diseases, obstetric and ocular pathologies, and cancers. To block the undesirable effects of this molecule, therapeutic antibodies have been developed. Herein, we review the multifaceted functions of CD146 in physiological and pathological angiogenesis and summarize the interest of using monoclonal antibodies for therapeutic purposes.

Selective modulation of trans-endothelial migration of lymphocyte subsets in multiple sclerosis patients under fingolimod treatment

Multiple sclerosis (MS) is an autoimmune disorder where auto-aggressive T cells target the central nervous system (CNS), causing demyelination. The trans-endothelial migration of leucocytes across the blood-brain barrier (BBB) is one of the earliest CNS events in MS pathogenesis. We examined the effect of the disease state and treatment with fingolimod on the transmigration of peripheral blood mononuclear cells (PBMCs) in an in vitro BBB model. Patients' leucocyte numbers, subsets and phenotypes were assessed by flow cytometry. As expected, fingolimod treatment induced a significant reduction in T cell and B cell numbers compared to untreated MS patients and healthy controls. Interestingly fingolimod led to a marked reduction of CD4+ and a significant increase in CD8⁺ cell numbers. In migrated cells, only CD3⁺ cell numbers were reduced in fingolimod-treated, compared to untreated patients; it had no effect on B cell or monocyte transmigration. T cells were then differentiated into naïve, effector and memory subsets based on their expression of CCR7. This showed that MS patients had increased numbers of effector memory CD4⁺ cells re-expressing CD45RA (TEMRA) and a decrease in central memory (CM) CD8⁺ cells. The former was corrected by fingolimod, while the latter was not. CM CD4⁺ and CD8⁺ cells migrated across BBB more efficiently in fingolimod-treated patients. We found that while fingolimod reduced the proportions of naïve CD19⁺ B cells, it significantly increased the proportions of these cells which migrated. When B cells were further stratified based on CD24, CD27 and CD38 expression, the only effect of fingolimod was an enhancement of CD24^hiCD27⁺ B cell migration, compared to untreated MS patients. The migratory capacities of CD8^hi Natural Killer (NK), CD8^dim NK and NK-T cells were also reduced by fingolimod. While the disease-modifying effects of fingolimod are currently explained by its effect on reducing circulating auto-aggressive lymphocytes, our data suggests that fingolimod may also have a direct though differential effect on the trans-endothelial migration of circulating lymphocyte populations.

Flow cytometry what you see matters: Enhanced clinical detection using image-based flow cytometry

Image-based flow cytometry combines the throughput of traditional flow cytometry with the ability to visually confirm findings and collect novel data that would not be possible otherwise. Since image-based flow cytometry borrows measurement parameters and analysis techniques from microscopy, it is possible to collect unique measures (i.e. nuclear translocation, co-localization, cellular synapse, cellular endocytosis, etc.) that would not be possible with traditional flow cytometry. The ability to collect unique outcomes has led many researchers to develop novel assays for the monitoring and detection of a variety of clinical conditions and diseases. In many cases, investigators have innovated and expanded classical assays to provide new insight regarding clinical conditions and chronic disease. Beyond human clinical applications, image-based flow cytometry has been used to monitor marine biology changes, nano-particles for solar cell production, and particle quality in pharmaceuticals. This review article summarizes work from the major scientists working in the field of image-based flow cytometry.

Melanoma cell adhesion molecule-positive CD8 T lymphocytes mediate central nervous system inflammation

OBJECTIVE

Although Tc17 lymphocytes are enriched in the central nervous system (CNS) of multiple sclerosis (MS) subjects and of experimental autoimmune encephalomyelitis (EAE) animals, limited information is available about their recruitment into the CNS and their role in neuroinflammation. Identification of adhesion molecules used by autoaggressive CD8(+) T lymphocytes to enter the CNS would allow further characterization of this pathogenic subset and could provide new therapeutic targets in MS. We propose that melanoma cell adhesion molecule (MCAM) is a surface marker and adhesion molecule used by pathogenic CD8(+) T lymphocytes to access the CNS.

METHODS

Frequency, phenotype, and function of MCAM(+) CD8(+) T lymphocytes was characterized using a combination of ex vivo, in vitro, in situ, and in vivo approaches in humans and mice, including healthy controls, MS subjects, and EAE animals.

RESULTS

Herein, we report that MCAM is expressed by human effector CD8(+) T lymphocytes and it is strikingly upregulated during MS relapses. We further demonstrate that MCAM(+) CD8(+) T lymphocytes express more interleukin 17, interferon γ, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor than MCAM(-) lymphocytes, and exhibit an enhanced killing capacity toward oligodendrocytes. MCAM blockade restricts the transmigration of CD8(+) T lymphocytes across human blood-brain barrier endothelial cells in vitro, and blocking or depleting MCAM in vivo reduces chronic neurological deficits in active, transfer, and spontaneous progressive EAE models.

INTERPRETATION

Our data demonstrate that MCAM identifies encephalitogenic CD8(+) T lymphocytes, suggesting that MCAM could represent a biomarker of MS disease activity and a valid target for the treatment of neuroinflammatory conditions.

Endothelial-binding, proinflammatory T cells identified by MCAM (CD146) expression: Characterization and role in human autoimmune diseases

A subset of T cells defined by the cell surface expression of MCAM (CD146) has been identified in the peripheral circulation of healthy individuals. These cells comprise approximately 3% of the pool of circulating T cells, have an effector memory phenotype, and are capable of producing several cytokines. Notably, the MCAM positive cells are enhanced for IL-17 production compared to MCAM negative effector memory T cells. These cells are committed to IL-17 production and do not require in vitro polarization with exogenous cytokines. MCAM positive T cells also demonstrate an increased ability to bind to endothelial monolayers. In numerous autoimmune diseases these cells are found at increased proportions in the peripheral circulation, and at the sites of active inflammation in patients with autoimmune disease, these cells appear in large numbers and are major contributors to IL-17 production. Studies to date have been performed with human subjects and it is uncertain if appropriate mouse models exist for this cell type. These cells could represent early components of the adaptive immune response and serve as targets of therapy in these diseases, although much work remains to be performed in order to discern the exact nature and function of these cells.