scholarly journals Psoriatic T cells recognize neolipid antigens generated by mast cell phospholipase delivered by exosomes and presented by CD1a

2016 ◽  
Vol 213 (11) ◽  
pp. 2399-2412 ◽  
Author(s):  
Ka Lun Cheung ◽  
Rachael Jarrett ◽  
Sumithra Subramaniam ◽  
Maryam Salimi ◽  
Danuta Gutowska-Owsiak ◽  
...  
Keyword(s):  
T Cells ◽  
Mast Cell ◽  
Therapeutic Potential ◽  
T Helper ◽  
T Helper 17 ◽  
Lipid Antigens ◽  
T Cell Antigens ◽  
Cell Release ◽  
Antigen Presenting ◽  
Psoriatic Lesions

Psoriasis is a chronic inflammatory skin disease associated with a T helper 17 response. Yet, it has proved challenging to identify relevant peptide-based T cell antigens. Antigen-presenting Langerhans cells show a differential migration phenotype in psoriatic lesions and express constitutively high levels of CD1a, which presents lipid antigens to T cells. In addition, phospholipase A2 (PLA2) is highly expressed in psoriatic lesions and is known to generate neolipid skin antigens for recognition by CD1a-reactive T cells. In this study, we observed expression of a cytoplasmic PLA2 (PLA2G4D) in psoriatic mast cells but, unexpectedly, also found PLA2G4D activity to be extracellular. This was explained by IFN-α–induced mast cell release of exosomes, which transferred cytoplasmic PLA2 activity to neighboring CD1a-expressing cells. This led to the generation of neolipid antigens and subsequent recognition by lipid-specific CD1a-reactive T cells inducing production of IL-22 and IL-17A. Circulating and skin-derived T cells from patients with psoriasis showed elevated PLA2G4D responsiveness compared with healthy controls. Overall, these data present an alternative model of psoriasis pathogenesis in which lipid-specific CD1a-reactive T cells contribute to psoriatic inflammation. The findings suggest that PLA2 inhibition or CD1a blockade may have therapeutic potential for psoriasis.

scholarly journals OX40L–OX40 Signaling in Atopic Dermatitis

2021 ◽  
Vol 10 (12) ◽  
pp. 2578
Author(s):  
Masutaka Furue ◽  
Mihoko Furue
Keyword(s):  
T Cells ◽  
Atopic Dermatitis ◽  
Memory T Cells ◽  
Effector Memory ◽  
T Helper ◽  
T Helper 1 ◽  
Therapeutic Success ◽  
T Helper 2 ◽  
Promising Target ◽  
Antigen Presenting

OX40 is one of the co-stimulatory molecules expressed on T cells, and it is engaged by OX40L, primarily expressed on professional antigen-presenting cells such as dendritic cells. The OX40L–OX40 axis is involved in the sustained activation and expansion of effector T and effector memory T cells, but it is not active in naïve and resting memory T cells. Ligation of OX40 by OX40L accelerates both T helper 1 (Th1) and T helper 2 (Th2) effector cell differentiation. Recent therapeutic success in clinical trials highlights the importance of the OX40L–OX40 axis as a promising target for the treatment of atopic dermatitis.

scholarly journals Development of Stable Chimeric IL-15 for Trans-Presentation by the Antigen Presenting Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Manoj Patidar ◽  
Naveen Yadav ◽  
Sarat K. Dalai
Keyword(s):  
T Cells ◽  
T Cell ◽  
Half Life ◽  
Therapeutic Potential ◽  
Chimeric Protein ◽  
Antigen Presenting Cells ◽  
T Cell Response ◽  
Antigen Presenting

IL-15 is one of the important biologics considered for vaccine adjuvant and treatment of cancer. However, a short half-life and poor bioavailability limit its therapeutic potential. Herein, we have structured IL-15 into a chimeric protein to improve its half-life enabling greater bioavailability for longer periods. We have covalently linked IL-15 with IgG2 base to make the IL-15 a stable chimeric protein, which also increased its serum half-life by 40 fold. The dimeric structure of this kind of IgG based biologics has greater stability, resistance to proteolytic cleavage, and less frequent dosing schedule with minimum dosage for achieving the desired response compared to that of their monomeric forms. The structured chimeric IL-15 naturally forms a dimer, and retains its affinity for binding to its receptor, IL-15Rβ. Moreover, with the focused action of the structured chimeric IL-15, antigen-presenting cells (APC) would transpresent chimeric IL-15 along with antigen to the T cell, that will help the generation of quantitatively and qualitatively better antigen-specific memory T cells. In vitro and in vivo studies demonstrate the biological activity of chimeric IL-15 with respect to its ability to induce IL-15 signaling and modulating CD8+ T cell response in favor of memory generation. Thus, a longer half-life, dimeric nature, and anticipated focused transpresentation by APCs to the T cells will make chimeric IL-15 a super-agonist for memory CD8+ T cell responses.

scholarly journals IL-17+ Mast Cell/T Helper Cell Axis in the Early Stages of Acne

2021 ◽  
Vol 12 ◽  
Author(s):  
Yoan Eliasse ◽  
Edouard Leveque ◽  
Lucile Garidou ◽  
Louise Battut ◽  
Brienne McKenzie ◽  
...  
Keyword(s):  
T Cells ◽  
Mast Cell ◽  
Mast Cells ◽  
Immune Cell ◽  
T Helper Cell ◽  
Helper Cell ◽  
T Helper ◽  
Cell Axis ◽  
Early Stages ◽  
Cutibacterium Acnes

Acne is a multifactorial disease driven by physiological changes occurring during puberty in the pilosebaceous unit (PSU) that leads to sebum overproduction and a dysbiosis involving notably Cutibacterium acnes. These changes in the PSU microenvironment lead to a shift from a homeostatic to an inflammatory state. Indeed, immunohistochemical analyses have revealed that inflammation and lymphocyte infiltration can be detected even in the infraclinical acneic stages, highlighting the importance of the early stages of the disease. In this study, we utilized a robust multi-pronged approach that included flow cytometry, confocal microscopy, and bioinformatics to comprehensively characterize the evolution of the infiltrating and resident immune cell populations in acneic lesions, beginning in the early stages of their development. Using a discovery cohort of 15 patients, we demonstrated that the composition of immune cell infiltrate is highly dynamic in nature, with the relative abundance of different cell types changing significantly as a function of clinical lesion stage. Within the stages examined, we identified a large population of CD69+ CD4+ T cells, several populations of activated antigen presenting cells, and activated mast cells producing IL-17. IL-17+ mast cells were preferentially located in CD4+ T cell rich areas and we showed that activated CD4+ T cells license mast cells to produce IL-17. Our study reveals that mast cells are the main IL-17 producers in the early stage of acne, underlying the importance of targeting the IL-17+ mast cell/T helper cell axis in therapeutic approaches.

scholarly journals CD4+T Cells: Differentiation and Functions

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Rishi Vishal Luckheeram ◽  
Rui Zhou ◽  
Asha Devi Verma ◽  
Bing Xia
Keyword(s):  
T Cells ◽  
Transcription Factors ◽  
T Cell ◽  
Cytokine Signaling ◽  
T Helper ◽  
T Helper 1 ◽  
T Helper 17 ◽  
Differentiated Cells ◽  
Follicular Helper ◽  
Follicular Helper T Cell

CD4+T cells are crucial in achieving a regulated effective immune response to pathogens. Naive CD4+T cells are activated after interaction with antigen-MHC complex and differentiate into specific subtypes depending mainly on the cytokine milieu of the microenvironment. Besides the classical T-helper 1 and T-helper 2, other subsets have been identified, including T-helper 17, regulatory T cell, follicular helper T cell, and T-helper 9, each with a characteristic cytokine profile. For a particular phenotype to be differentiated, a set of cytokine signaling pathways coupled with activation of lineage-specific transcription factors and epigenetic modifications at appropriate genes are required. The effector functions of these cells are mediated by the cytokines secreted by the differentiated cells. This paper will focus on the cytokine-signaling and the network of transcription factors responsible for the differentiation of naive CD4+T cells.

scholarly journals Notch signaling pathway regulates CD4+CD25+CD127dim/− regulatory T cells and T helper 17 cells function in gastric cancer patients

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Lu Yang ◽  
Ke-Lei Zhao ◽  
Lei Qin ◽  
Dan-Xia Ji ◽  
Bin Zhang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
T Cells ◽  
Regulatory T Cells ◽  
Notch Signaling ◽  
Cancer Progression ◽  
Th17 Cells ◽  
Cellular Proliferation ◽  
Current Data ◽  
T Helper ◽  
T Helper 17

Abstract Regulatory T cells (Tregs) and T helper 17 (Th17) cells contribute to cancer progression and prognosis. However, regulatory factors associated with Tregs–Th17 balance were not completely understood. We previously demonstrated an immune-modulatory capacity by Notch signaling inactivation to reverse Tregs–Th17 disequilibrium in chronic hepatitis C. Thus, the aim of current study was to assess the role of Notch signaling in modulation Tregs and Th17 cells function in gastric cancer (GC) patients. A total of 51 GC patients and 18 normal controls (NCs) were enrolled. Notch1 and Notch2 mRNA expressions were semiquantified by real-time polymerase chain reaction. Tregs/Th17 percentages, transcriptional factors, and cytokines production were investigated in response to the stimulation of Notch signaling inhibitor DAPT. Both Notch1 and Notch2 mRNA expressions were elevated in GC tissues and peripheral bloods in GC patients. CD4+CD25+CD127dim/− Tregs and Th17 cells percentage was also elevated in GC patients compared with in NCs. DAPT treatment did not affect frequency of either circulating Tregs or Th17 cells, however, reduced FoxP3/RORγt mRNA expression and interleukin (IL)-35/IL-17 production in purified CD4+ T cells from GC patients. Moreover, blockade of Notch signaling also inhibited the suppressive function of purified CD4+CD25+CD127dim/− Tregs from GC patients, which presented as elevation of cellular proliferation and IL-35 secretion. The current data further provided mechanism underlying Tregs–Th17 balance in GC patients. The link between Notch signaling and Th cells might lead to a new therapeutic target for GC patients.

scholarly journals CD4 T cell-intrinsic role for the T helper 17 signature cytokine IL-17: Effector resistance to immune suppression

2020 ◽  
Vol 117 (32) ◽  
pp. 19408-19414 ◽  
Author(s):  
Michael P. Crawford ◽  
Sushmita Sinha ◽  
Pranav S. Renavikar ◽  
Nicholas Borcherding ◽  
Nitin J. Karandikar
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Suppression ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
T Helper ◽  
T Helper 17 ◽  
Immune Resistance ◽  
Inflammatory Bowel

Untoward effector CD4+ T cell responses are kept in check by immune regulatory mechanisms mediated by CD4+ and CD8+ T cells. CD4+ T helper 17 (Th17) cells, characterized by IL-17 production, play important roles in the pathogenesis of autoimmune diseases (such as arthritis, multiple sclerosis, psoriasis, inflammatory bowel disease, among others) and in the host response to infection and cancer. Here, we demonstrate that human CD4+ T cells cells exposed to a Th17-differentiating milieu are significantly more resistant to immune suppression by CD8+ T cells compared to control Th0 cells. This resistance is mediated, in part, through the action of IL-17A, IL-17F, and IL-17AF heterodimer through their receptors (IL-17RA and IL-17RC) on CD4+ T cells themselves, but not through their action on CD8+ T cells or APC. We further show that IL-17 can directly act on non-Th17 effector CD4+ T cells to induce suppressive resistance, and this resistance can be reversed by blockade of IL-1β, IL-6, or STAT3. These studies reveal a role for IL-17 cytokines in mediating CD4-intrinsic immune resistance. The pathways induced in this process may serve as a critical target for future investigation and immunotherapeutic intervention.

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