Search results for "Allergy"
showing 10 items of 3181 documents
Innate Immune Cells' Contribution to Systemic Lupus Erythematosus
2019
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the presence of autoantibodies against nuclear antigens, immune complex deposition, and tissue damage in the kidneys, skin, heart and lung. Because of the pathogenic role of antinuclear antibodies and autoreactive T cells in SLE, extensive efforts have been made to demonstrate how B cells act as antibody-producing or as antigen-presenting cells that can prime autoreactive T cell activation. With the discovery of new innate immune cells and inflammatory mediators, innate immunity is emerging as a key player in disease pathologies. Recent work over the last decade has highlighted the importance of innate immun…
Metabolism via arginase or nitric oxide synthase: two competing arginine pathways in macrophages
2014
Macrophages play a major role in the immune system, both as antimicrobial effector cells and as immunoregulatory cells, which induce, suppress or modulate adaptive immune responses. These key aspects of macrophage biology are fundamentally driven by the phenotype of macrophage arginine metabolism that is prevalent in an evolving or ongoing immune response. M1 macrophages express the enzyme nitric oxide synthase (NOS), which metabolizes arginine to nitric oxide (NO) and citrulline. NO can be metabolized to further downstream reactive nitrogen species, while citrulline might be reused for efficient NO synthesis via the citrulline-NO cycle. M2 macrophages are characterized by expression of the…
The Immunology of Zoonotic Infections
2012
Zoonotic infections are in general defined as infections transmitted from animal to man (and less frequently vice versa), either directly (through contact or contact with animal products) or indirectly (through an intermediate vector as an arthropod or an insect) [1]. Although the burden of zoonotic infections worldwide is major, both in terms of immediate and long-term morbidity and mortality [2, 3] and in terms of emergence/reemergence and socioeconomical, ecological, and political correlations [4], scientific and public health interest and funding for these diseases remain relatively minor. Zoonoses include diseases induced by diverse pathogens (bacteria, viruses, fungi, and parasites), …
Heat-Shock Proteins in Autoimmunity
2013
Heat shock proteins (HSPs), also known as “stress proteins,” are among the highly conserved and immunogenic proteins shared among diverse groups of microbial agents and mammals [1]. Heat and other types of stressful stimuli can increase the cellular expression of HSPs. These proteins have been categorized into different families according to their molecular mass, for example, HSP110, HSP90, HSP70, HSP60, HSP40, HSP20-30, and HSP10 [1–3]. For uniformity, guidelines for the nomenclature of various human HSP families have been proposed [4]. Under physiological conditions, the ubiquitously distributed HSPs maintain the integrity and function of other cellular proteins in stressful conditions. H…
Protection of Mice from Acute Graft-versus-Host Disease Requires CD28 Co-stimulation on Donor CD4+ Foxp3+ Regulatory T Cells
2017
Acute graft-versus-host disease (aGvHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell plus T cell transplantation (allo-HSCT). In this study, we investigated the requirement for CD28 co-stimulation of donor CD4\(^{+}\) conventional (CD4\(^{+}\)CD25\(^{-}\)Foxp3\(^{-}\), Tconv) and regulatory (CD4\(^{+}\)CD25\(^{+}\)Foxp3\(^{+}\), Treg) T cells in aGvHD using tamoxifen-inducible CD28 knockout (iCD28KO) or wild-type (wt) littermates as donors of CD4\(^{+}\) Tconv and Treg. In the highly inflammatory C57BL/6 into BALB/c allo-HSCT transplantation model, CD28 depletion on donor CD4\(^{+}\) Tconv reduced clinical signs of aGvHD, but did not significantly pro…
IL-12 Expands and Differentiates Human Vγ2Vδ2 T Effector Cells Producing Antimicrobial Cytokines and Inhibiting Intracellular Mycobacterial Growth
2019
While IL-12 plays a key role in differentiation of protective CD4+ Th1 response, little is known about mechanisms whereby IL-12 differentiates other T-cell populations. Published studies suggest that predominant Vγ2Vδ2 T cells in humans/nonhuman primates (NHP) are a fast-acting T-cell subset, with capacities to rapidly expand and produce Th1 and cytotoxic cytokines in response to phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) produced by Mycobacterium tuberculosis (Mtb) or others. However, whether IL-12 signaling pathway mediates fast-acting and Th1 or anti-microbial features of Vγ2Vδ2 T cells remains poorly defined. Here, we show that IL-12, but not other IL-12 fami…
Role of Peripheral Immune Cells-Mediated Inflammation on the Process of Neurodegenerative Diseases
2020
Neurodegenerative diseases are characterized by progressive loss of selectively vulnerable neuronal populations, which contrasts with selectively static loss of neurons due to toxic or metabolic disorders. The mechanisms underlying their progressive nature remain unknown. To date, a timely and well-controlled peripheral inflammatory reaction is verified to be essential for neurodegenerative diseases remission. The influence of peripheral inflammation on the central nervous system is closely related to immune cells activation in peripheral blood. The immune cells activation participated in the uncontrolled and prolonged inflammation that drives the chronic progression of neurodegenerative di…
Neutrophils: Between host defence, immune modulation, and tissue injury.
2015
Neutrophils, the most abundant human immune cells, are rapidly recruited to sites of infection, where they fulfill their life-saving antimicrobial functions. While traditionally regarded as short-lived phagocytes, recent findings on long-term survival, neutrophil extracellular trap (NET) formation, heterogeneity and plasticity, suppressive functions, and tissue injury have expanded our understanding of their diverse role in infection and inflammation. This review summarises our current understanding of neutrophils in host-pathogen interactions and disease involvement, illustrating the versatility and plasticity of the neutrophil, moving between host defence, immune modulation, and tissue da…
Are Toll-like receptors and decoy receptors involved in the immunopathogenesis of systemic lupus erythematosus and lupus-like syndromes?
2011
In this paper we focus our attention on the role of two families of receptors, Toll-like receptors (TLR) and decoy receptors (DcR) involved in the generation of systemic lupus erythematosus (SLE) and lupus-like syndromes in human and mouse models. To date, these molecules were described in several autoimmune disorders such as rheumatoid arthritis, antiphospholipids syndrome, bowel inflammation, and SLE. Here, we summarize the findings of recent investigations on TLR and DcR and their role in the immunopathogenesis of the SLE.
CD11b Regulates Fungal Outgrowth but Not Neutrophil Recruitment in a Mouse Model of Invasive Pulmonary Aspergillosis
2019
Abstract Background and Aims: In immunosuppressed individuals Aspergillus (A.) fumigatus is a frequent cause of invasive pulmonary aspergillosis (IPA) which is highly associated with relevant morbidity and mortality. Moreover, it often occurs in patients suffering from leukocyte-adhesion deficiency type 1 (LAD1) which is triggered by a functional loss of CD18 in ß2 integrin receptors as these receptors consist of an alpha subunit (CD11a-CD11d) and CD18 as the common beta subunit. ß2 integrin receptors are differentially expressed by leukocytes, and are required for cell-cell interaction, transendothelial migration, uptake of opsonized pathogens, and cell signaling processes. Here, we asked …