scholarly journals Inflammation and Immune Response in COPD: Where Do We Stand?

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Nikoletta Rovina ◽  
Antonia Koutsoukou ◽  
Nikolaos G. Koulouris
Keyword(s):  
Immune Responses ◽  
Bacterial Infections ◽  
Severe Disease ◽  
Critical Role ◽  
Specific Pattern ◽  
Innate Immune ◽  
Danger Signal ◽  
Cd4 Cells ◽  
Adaptive Immune ◽  
Molecular Patterns

Increasing evidence indicates that chronic inflammatory and immune responses play key roles in the development and progression of COPD. Recent data provide evidence for a role in the NLRP3 inflammasome in the airway inflammation observed in COPD. Cigarette smoke activates innate immune cells by triggering pattern recognition receptors (PRRs) to release “danger signal”. These signals act as ligands to Toll-like receptors (TLRs), triggering the production of cytokines and inducing innate inflammation. In smokers who develop COPD there appears to be a specific pattern of inflammation in the airways and parenchyma as a result of both innate and adaptive immune responses, with the predominance of CD8+ and CD4+ cells, and in the more severe disease, with the presence of lymphoid follicles containing B lymphocytes and T cells. Furthermore, viral and bacterial infections interfere with the chronic inflammation seen in stable COPD and exacerbations via pathogen-associated molecular patterns (PAMPs). Finally, autoimmunity is another novel aspect that may play a critical role in the pathogenesis of COPD. This review is un update of the currently discussed roles of inflammatory and immune responses in the pathogenesis of COPD.

scholarly journals Crosstalk between Dendritic Cells and Immune Modulatory Agents against Sepsis

Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 323 ◽  
Author(s):  
Guoying Wang ◽  
Xianghui Li ◽  
Lei Zhang ◽  
Abualgasim Elgaili Abdalla ◽  
Tieshan Teng ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Critical Role ◽  
Innate Immune ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Th2 Responses ◽  
Novel Strategy

Dendritic cells (DCs) play a critical role in the immune system which sense pathogens and present their antigens to prime the adaptive immune responses. As the progression of sepsis occurs, DCs are capable of orchestrating the aberrant innate immune response by sustaining the Th1/Th2 responses that are essential for host survival. Hence, an in-depth understanding of the characteristics of DCs would have a beneficial effect in overcoming the obstacle occurring in sepsis. This paper focuses on the role of DCs in the progression of sepsis and we also discuss the reverse sepsis-induced immunosuppression through manipulating the DC function. In addition, we highlight some potent immunotherapies that could be used as a novel strategy in the early treatment of sepsis.

scholarly journals Dengue Immunopathogenesis: A Crosstalk between Host and Viral Factors Leading to Disease: PART II - DENV Infection, Adaptive Immune Responses, and NS1 Pathogenesis

2020 ◽  
Author(s):  
Henry Puerta-Guardo ◽  
Scott B. Biering ◽  
Eva Harris ◽  
Norma Pavia-Ruz ◽  
Gonzalo Vázquez-Prokopec ◽  
...  
Keyword(s):  
Immune Responses ◽  
Nonstructural Protein ◽  
Severe Disease ◽  
Critical Role ◽  
Denv Infection ◽  
Severe Dengue ◽  
Adaptive Immune Responses ◽  
Dengue Disease ◽  
Adaptive Immune ◽  
Monocytes And Macrophages

Severe disease is associated with serial infection with DENV of different serotypes. Thus, primary DENV infections normally cause asymptomatic infections, and secondary heterotypic infections with a new DENV serotype potentially increase the risks of developing severe disease. Despite many proposed hypotheses trying to explain it, the exact immunological mechanism leading to severe dengue disease is unknown. In turn, severe manifestations are believed to be a consequence of the combinations of many immunopathogenic mechanisms involving viral and host factors leading to increased pathogenesis and disease. Of these mechanisms, the adaptive immune response has been proposed to play a critical role in the development of severe dengue manifestations. This includes the effect of non-neutralizing but enhancing antibodies produced during primary infections, which results in enhanced-DENV infection of Fc-γ-receptor-expressing cells (e.g. monocytes and macrophages) during DENV heterotypic exposure in a phenomenon called antibody-dependent enhancement (ADE); the increased activation of memory T cells during secondary infections, which has low affinity for the current infecting serotype and high affinity for a past infection with a different serotype known as the original antigenic sin; the unbalanced production of pro-inflammatory cytokines that have a direct effect on vascular endothelial cells resulting in plasma leak in a phenomenon known as cytokine storm; and the excessive activation of the complement system that causes exacerbated inflammatory responses, increasing disease severity. In addition to the adaptive immune responses, a secreted viral factor known as the nonstructural protein 1 (NS1) has been recently proposed as the missing corner piece of the DENV pathogenesis influencing disease. This Part II of the chapter will discuss the interplay between the distinct host adaptive immune responses and viral factors that together contribute to the development of DENV pathogenesis and severe disease.

scholarly journals Impaired function and delayed regeneration of dendritic cells in COVID-19

2021 ◽  
Author(s):  
Elena Winheim ◽  
Linus Rinke ◽  
Konstantin Lutz ◽  
Anna Reischer ◽  
Alexandra Leutbecher ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Severe Disease ◽  
Innate Immune ◽  
Severe Illness ◽  
Adaptive Immune ◽  
Follicular Helper ◽  
Secondary Infections ◽  
Classical Monocytes ◽  
Antibody Secreting Cells

Disease manifestations in COVID-19 range from mild to severe illness associated with a dysregulated innate immune response. Alterations in function and regeneration of dendritic cells (DC) and monocytes may contribute to immunopathology and influence adaptive immune responses in COVID-19 patients. We analyzed circulating DC and monocyte subsets in 65 hospitalized COVID-19 patients with mild/moderate or severe disease from acute disease to recovery and in healthy controls. Persisting reduction of all DC subpopulations was accompanied by an expansion of proliferating Lineage- HLADR+ cells lacking DC markers. Increased frequency of the recently discovered CD163+ CD14+ DC3 subpopulation in patients with more severe disease was associated with systemic inflammation, activated T follicular helper cells, and antibody-secreting cells. Persistent downregulation of CD86 and upregulation of PD-L1 in conventional DC (cDC2 and DC3) and classical monocytes associated with a reduced capacity to stimulate naive CD4+ T cells correlated with disease severity. Long-lasting depletion and functional impairment of DCs and monocytes may have consequences for susceptibility to secondary infections and therapy of COVID-19 patients.

scholarly journals Innate Immune Effectors in Mycobacterial Infection

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Hiroyuki Saiga ◽  
Yosuke Shimada ◽  
Kiyoshi Takeda
Keyword(s):  
Immune Responses ◽  
Bacterial Infections ◽  
Mycobacterial Infection ◽  
Innate Immune ◽  
Pathogenic Microorganisms ◽  
Lipocalin 2 ◽  
Innate Immune Responses ◽  
Active Vitamin ◽  
Lectin Receptors ◽  
Adaptive Immune

Tuberculosis, which is caused by infection withMycobacterium tuberculosis(Mtb), remains one of the major bacterial infections worldwide. Host defense against Mtb is mediated by a combination of innate and adaptive immune responses. In the last 15 years, the mechanisms for activation of innate immunity have been elucidated. Toll-like receptors (TLRs) have been revealed to be critical for the recognition of pathogenic microorganisms including mycobacteria. Subsequent studies further revealed that NOD-like receptors and C-type lectin receptors are responsible for the TLR-independent recognition of mycobacteria. Several molecules, such as active vitamin D3, secretary leukocyte protease inhibitor, and lipocalin 2, all of which are induced by TLR stimulation, have been shown to direct innate immune responses to mycobacteria. In addition, Irgm1-dependent autophagy has recently been demonstrated to eliminate intracellular mycobacteria. Thus, our understanding of the mechanisms for the innate immune response to mycobacteria is developing.

Toll-like receptors and diabetes: a therapeutic perspective

2011 ◽  
Vol 122 (5) ◽  
pp. 203-214 ◽  
Author(s):  
Mohan R. Dasu ◽  
Sandra Ramirez ◽  
Roslyn R. Isseroff
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
Undiagnosed Diabetes ◽  
Innate Immune Responses ◽  
Toll Like Receptors ◽  
Adaptive Immune ◽  
Molecular Patterns ◽  
Therapeutic Perspective

Diabetes is a mutifactorial metabolic disorder that leads to a number of complications. Diabetes is estimated to affect 36 million people in the U.S.A., and the prevalence of diagnosed and undiagnosed diabetes is at 9.3% and continues to rise. Evidence from experimental animal models as well as humans has indicated that systemic inflammation plays a role in the pathophysiological processes of diabetes and is facilitated by innate immune responses. TLRs (Toll-like receptors) are key innate immune receptors that recognize conserved PAMPs (pathogen-associated molecular patterns), induce inflammatory responses essential for host defences and initiate an adaptive immune response. Although TLR expression is increased in a plethora of inflammatory disorders, the effects of metabolic aberrations on TLRs and their role in diabetes and its complications is still emerging. In the present paper, we provide a systematic review on how TLRs play a detrimental role in the pathogenic processes [increased blood sugar, NEFAs (non-esterified ‘free’ fatty acids), cytokines and ROS (reactive oxygen species)] that manifest diabetes. Furthermore, we will highlight some of the therapeutic strategies targeted at decreasing TLRs to abrogate inflammation in diabetes that may eventually result in decreased complications.

scholarly journals Classical dendritic cells as a unique immune cell lineage

2012 ◽  
Vol 209 (6) ◽  
pp. 1053-1056 ◽  
Author(s):  
Boris Reizis
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Immune Cell ◽  
Critical Role ◽  
Cell Lineage ◽  
Specific Pattern ◽  
Adaptive Immune ◽  
Definition Of

Despite the critical role of classical dendritic cells (cDCs) in the initiation of adaptive immune responses, the genetic and phenotypic definition of cDCs remains moot. Two new studies designate Zbtb46 as a novel transcription factor that is specifically expressed in all cDCs in both humans and mice. Although Zbtb46 appears dispensable for cDC development, its specific pattern of expression supports the notion that cDCs constitute a unique immune cell lineage. Furthermore, these two studies provide novel tools that will aid in the study of cDC progenitors, visualization of cDCs in vivo, and depletion of cDCs for functional analysis.

scholarly journals Role of the Innate Immunity Signaling Pathway in the Pathogenesis of Sjögren’s Syndrome

2021 ◽  
Vol 22 (6) ◽  
pp. 3090
Author(s):  
Toshimasa Shimizu ◽  
Hideki Nakamura ◽  
Atsushi Kawakami
Keyword(s):  
Immune Responses ◽  
Sjögren's Syndrome ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Innate Immune ◽  
Type I ◽  
Type I Ifn ◽  
Adaptive Immune ◽  
Sjögren‘S Syndrome

Sjögren’s syndrome (SS) is a systemic autoimmune disease characterized by chronic inflammation of the salivary and lacrimal glands and extra-glandular lesions. Adaptive immune response including T- and B-cell activation contributes to the development of SS. However, its pathogenesis has not yet been elucidated. In addition, several patients with SS present with the type I interferon (IFN) signature, which is the upregulation of the IFN-stimulated genes induced by type I IFN. Thus, innate immune responses including type I IFN activity are associated with SS pathogenesis. Recent studies have revealed the presence of activation pattern recognition receptors (PRRs) including Toll-like receptors, RNA sensor retinoic acid-inducible gene I and melanoma differentiation-associated gene 5, and inflammasomes in infiltrating and epithelial cells of the salivary glands among patients with SS. In addition, the activation of PRRs via the downstream pathway such as the type I IFN signature and nuclear factor kappa B can directly cause organ inflammation, and it is correlated with the activation of adaptive immune responses. Therefore, this study assessed the role of the innate immune signal pathway in the development of inflammation and immune abnormalities in SS.

TLR4 regulates rabies virus-induced humoral immunity through recruitment of cDC2 to lymph organs

2021 ◽  
Author(s):  
Chen Chen ◽  
Chengguang Zhang ◽  
Haoqi Li ◽  
Zongmei Wang ◽  
Yueming Yuan ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Rabies Virus ◽  
Humoral Immunity ◽  
Humoral Immune Response ◽  
Critical Role ◽  
Wild Type ◽  
Humoral Immune ◽  
Specific Igg ◽  
Molecular Patterns

Rabies, caused by rabies virus (RABV), is fatal to both humans and animals around the world. Effective clinical therapy for rabies has not been achieved, and vaccination is the most effective means of preventing and controlling rabies. Although different vaccines, such as live attenuated and inactivated vaccines, can induce different immune responses, different expression of pattern recognition receptors (PRRs) also causes diverse immune responses. Toll-like receptor 4 (TLR4) is a pivotal PRR that induces cytokine production and bridges innate and adaptive immunity. Importantly, TLR4 recognizes various virus-derived pathogen-associated molecular patterns (PAMPs) and virus-induced damage-associated molecular patterns (DAMPs), usually leading to the activation of immune cells. However, the role of TLR4 in the humoral immune response induced by RABV has not been revealed yet. Based on TLR4-deficient ( TLR4 -/- ) and wild-type (WT) mouse models, we report that TLR4-dependent recruitment of the conventional type-2 dendritic cells (CD8α - CD11b + cDC2) into secondary lymph organs (SLOs) is critical for antigen presentation. cDC2-initiated differentiation of Tfh cells promotes the proliferation of germinal centre (GC) B cells, the formation of GCs, and the production of plasma cells (PCs), all of which contribute to the production of RABV-specific IgG and virus-neutralizing antibodies (VNAs). Collectively, our work demonstrates that TLR4 is necessary for the recruitment of cDC2 and for the induction of RABV-induced humoral immunity, which is regulated by the cDC2-Tfh-GC B axis. IMPORTANCE Vaccination is the most efficient method to prevent rabies. TLR4, a well-known immune sensor, plays a critical role in initiating innate immune response. Here, we found that TLR4 deficiency ( TLR4 -/- ) mice suppressed the induction of humoral immune response after immunization with rabies virus (RABV), including reduced production of VNAs and RABV-specific IgG, compared with that occurred in wild-type (WT) mice. As a consequence, TLR4 -/- mice exhibited higher mortality than WT mice after challenge with virulent RABV. Importantly, further investigation found that TLR4 signaling promoted the recruitment of cDC2 (CD8α + CD11b - ), a subset of cDCs known to induce CD4 + T cell immunity through their MHC-II presentation machinery. Our results imply that TLR4 is indispensable for an efficient humoral response to rabies vaccine, which provides new insight into the development of novel rabies vaccines.

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