Search results for " allergy"

Parallels and differences between innate and adaptive lymphocytes.

2016

Lymphocytes are essential in innate and adaptive immunity. Recent insights suggest that some innate lymphocytes execute functions with adaptive characteristics, while adaptive lymphocytes can operate in ways reminiscent of innate cells. Rather than partitioning lymphocytes according to the type of effector function they execute, we propose that a relevant discrimination relates to the existence of conventional T cells in a naive state. The naive state can be seen as an actively repressed condition that supports T cell diversity and enables the flexible differentiation of effector cells in a manner that best addresses the antigenic challenge. We discuss these considerations in the context of…

Gut-derived CD8+ tissue-resident memory T cells are expanded in the peripheral blood and synovia of SpA patients

2019

We read with interest the recently published paper from Qaiyum et al 1 demonstrating a novel integrin-expressing mature Crohn's disease (CD)8+ T cell population defined as CD49a+CD103+β7+CD29+ cells in the synovial fluids of ankylosing spondylitis (AS) patients. Although the authors did not analyse gut samples from AS patients, they speculate that these cells might be gut-derived cells. Interestingly, as stated by authors, the transcriptional and phenotypic signature of these cells is reminiscent of human tissue-resident memory T cells (TRM). TRM are a subset of cells important as the first line of defence from infection in mucosal tissues, never studied in spondyloarthritis (SpA).2 For cla…

Balanced Bcl-3 expression in murine CD4+T cells is required for generation of encephalitogenic Th17 cells

2017

The function of NF-κB family members is controlled by multiple mechanisms including the transcriptional regulator Bcl-3, an atypical member of the IκB family. By using a murine model of conditional Bcl-3 overexpression specifically in T cells, we observed impairment in the development of Th2, Th1 and Th17 cells. High expression of Bcl-3 promoted CD4+ T-cell survival, but at the same time suppressed proliferation in response to TCR stimulation, resulting in reduced CD4+ T-cell expansion. As a consequence, T cell specific overexpression of Bcl-3 led to reduced inflammation in the small intestine of mice applied with anti-CD3 in a model of gut inflammation. Moreover, impaired Th17-cell develop…

Guidelines for the use of flow cytometry and cell sorting in immunological studies

2017

The marriage between immunology and cytometry is one of the most stable and productive in the recent history of science. A rapid search in PubMed shows that, as of July 2017, using “flow cytometry immunology” as a search term yields more than 68 000 articles, the first of which, interestingly, is not about lymphocytes. It might be stated that, after a short engagement, the exchange of the wedding rings between immunology and cytometry officially occurred when the idea to link fluorochromes to monoclonal antibodies came about. After this, recognizing different types of cells became relatively easy and feasible not only by using a simple fluorescence microscope, but also by a complex and some…

IRF8 Transcription Factor Controls Survival and Function of Terminally Differentiated Conventional and Plasmacytoid Dendritic Cells, Respectively

2016

International audience; Interferon regulatory factor-8 (IRF8) has been proposed to be essential for development of monocytes, plasmacytoid dendritic cells (pDCs) and type 1 conventional dendritic cells (cDC1s) and remains highly expressed in differentiated DCs. Transcription factors that are required to maintain the identity of terminally differentiated cells are designated `' terminal selectors.'' Using BM chimeras, conditional Irf8(fl/fl) mice and various promotors to target Cre recombinase to different stages of monocyte and DC development, we have identified IRF8 as a terminal selector of the cDC1 lineage controlling survival. In monocytes, IRF8 was necessary during early but not late d…

Targeting Neoepitopes to Treat Solid Malignancies: Immunosurgery

2020

Successful outcome of immune checkpoint blockade in patients with solid cancers is in part associated with a high tumor mutational burden (TMB) and the recognition of private neoantigens by T-cells. The quality and quantity of target recognition is determined by the repertoire of ‘neoepitope’-specific T-cell receptors (TCRs) in tumor-infiltrating lymphocytes (TIL), or peripheral T-cells. Interferon gamma (IFN-γ), produced by T-cells and other immune cells, is essential for controlling proliferation of transformed cells, induction of apoptosis and enhancing human leukocyte antigen (HLA) expression, thereby increasing immunogenicity of cancer cells. TCR αβ-dependent therapies should account f…

2017

Bruton's tyrosine kinase (BTK) was initially discovered as a critical mediator of B cell receptor signaling in the development and functioning of adaptive immunity. Growing evidence also suggests multiple roles for BTK in mononuclear cells of the innate immune system, especially in dendritic cells and macrophages. For example, BTK has been shown to function in Toll-like receptor-mediated recognition of infectious agents, cellular maturation and recruitment processes, and Fc receptor signaling. Most recently, BTK was additionally identified as a direct regulator of a key innate inflammatory machinery, the NLRP3 inflammasome. BTK has thus attracted interest not only for gaining a more thoroug…

2020

Dendritic cells (DC) play a key role in the adaptive immune response due to their ability to present antigens and stimulate naive T cells. Many bacteria and viruses can efficiently target DC, resulting in impairment of their immunostimulatory function or elimination. Hence, the DC compartment requires replenishment following infection to ensure continued operational readiness of the adaptive immune system. Here, we investigated the molecular and cellular mechanisms of inflammation-induced DC generation. We found that infection with viral and bacterial pathogens as well as Toll-like receptor 9 (TLR9) ligation with CpG-oligodeoxynucleotide (CpG-ODN) expanded an erythropoietin (EPO)-dependent …

Conditional Gene-Targeting in Mice: Problems and Solutions.

2018

Secukinumab efficacy in patients with PsA is not dependent on patients' body mass index

2020

We read with interest the recently published paper from McGonagle et al 1 analysing the role of interleukin (IL)-17A in axial spondyloarthritis and psoriatic arthritis (PsA). The meta-analysis and functional study provided by the authors highlighted the efficacy of IL-17A block by secukinumab in the treatment of PsA. However, there is no mention of the role of body mass index (BMI), if any, in influencing the clinical response to secukinumab, given the lack of published data. PsA is a chronic inflammatory arthritis burdened by a series of metabolic comorbidities. Among them, obesity is very common in PsA, with a prevalence of 27%, as confirmed by a recent Spanish work.2 Obesity in PsA has b…