Coexpression of αβ and γδ TCRs bridges innate and adaptive immunity

2020 ◽  
Vol 12 (546) ◽  
pp. eabc8941
Author(s):  
Gerald P. Morris

T cells coexpressing αβ and γδ TCRs demonstrate characteristics of both αβ and γδ T cells, providing a link between innate and adaptive immune responses.

Vaccine ◽  
2020 ◽  
Vol 38 (5) ◽  
pp. 1015-1024
Author(s):  
Isabella A. Joubert ◽  
Daniel Kovacs ◽  
Sandra Scheiblhofer ◽  
Petra Winter ◽  
Evgeniia Korotchenko ◽  
...  

2002 ◽  
Vol 85 (4) ◽  
pp. 347-358 ◽  
Author(s):  
Zheng W. Chen

Accumulative evidence suggests that resident γδ T cells in epithelia are biologically distinct from systemic γδ T cells in the circulation. Murine resident γδ T cells have innate immune characteristics and play an important role in tissue homeostasis after damages. In contrast, a unique subset of circulating γδ T cells in primates, like αβ T cells, can mount adaptive immune responses in infections. This article compares biological features between resident and circulating γδ T cells.


2020 ◽  
Author(s):  
Kuai Yu ◽  
Yongjian Wu ◽  
Jingjing He ◽  
Xuefei Liu ◽  
Bo Wei ◽  
...  

Abstract Two typical features of uncontrolled inflammation, cytokine storm and lymphopenia, are associated with the severity of coronavirus disease 2019 (COVID-19), demonstrating that both innate and adaptive immune responses are involved in the development of this disease. Recent studies have explored the contribution of innate immune cells to the pathogenesis of the infection. However, the impact of adaptive immunity on this disease remains unknown. In order to clarify the role of adaptive immune response in COVID-19, we characterized the phenotypes of lymphocytes in PBMCs from patients at different disease stages using single-cell RNA sequencing (scRNA-seq) technology. Dynamics of the effector cell levels in lymphocytes revealed a distinct feature of adaptive immunity in severely affected patients, the coincidence of impaired cellular and enhanced humoral immune responses, suggesting that dysregulated adaptive immune responses advanced severe COVID-19. Excessive activation and exhaustion were observed in CD8 T effector cells, which might contribute to the lymphopenia. Interestingly, expression of Prothymosin alpha (PTMA), the proprotein of Tα1, was significantly increased in a group of CD8 T memory stem cells, but not in excessively activated T cells. We further showed that Tα1 significantly promoted the proliferation of activated T cells in vitro and relieved the lymphopenia in COVID-19 patients. Our data suggest that protection of T cells from excessive activation might be critical for the prevention of severe COVID-19.


2019 ◽  
Author(s):  
Isabella Joubert ◽  
Daniel Kovacs ◽  
Sandra Scheiblhofer ◽  
Petra Winter ◽  
Evgeniia Korotchenko ◽  
...  

AbstractBackgroundThe skin resembles an attractive target for vaccination due to its accessibility and abundance of resident immune cells. Cells like γδ T cells and mast cells (MCs) are part of the first line of defence against exogenous threats. Despite being important mediators for eliciting TH2 immune responses after epithelial stress, γδ T cell and MC function still remains to be completely understood. Here, we aimed to characterize their roles in shaping adaptive immune responses after laser-mediated epicutaneous immunization (EPI).Methodsγδ T cell knock out, MC depleted, and wildtype control mice were immunized with mannan-conjugated grass pollen allergen Phl p 5 (P5-MN) by laser-mediated EPI. After 2-3 immunizations, cytokine expression, T helper polarization, and antigen-specific IgG1/IgE levels were analysed. The local cytokine/chemokine milieu after laser microporation was determined.ResultsWhile the majority of inflammatory chemokines and cytokines induced by laser treatment was not affected by the presence of γδ T cells or MCs, RANTES, was elevated in γδ T cell knock out mice, and GROα and TSLP, were significantly decreased after MC depletion. However, absence of γδ T cells or depletion of MC had no substantial effect on adaptive humoral or cellular immune responses after laser-mediated EPI, except for slightly reduced IgG1 and effector T cell levels in MC depleted mice.Conclusionsγδ T cells did not play a pivotal role in shaping the humoral and cellular adaptive immune response after laser-mediated EPI, whereas MC depletion decreased numbers of effector T cells, indicating a potential role of MCs in the activation and maturation of T cells after EPI.HighlightsLaser microporation induces an inflammatory chemokine milieu at the site of immunizationγδ T cells and mast cells contribute to the steady-state or damage-induced cytokine milieu in the skinγδ T cells and mast cells are dispensable for adaptive immunity after laser-mediated immunization


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Dragana Odobasic ◽  
A. Richard Kitching ◽  
Stephen R. Holdsworth

Neutrophils are no longer seen as leukocytes with a sole function of being the essential first responders in the removal of pathogens at sites of infection. Being armed with numerous pro- and anti-inflammatory mediators, these phagocytes can also contribute to the development of various autoimmune diseases and can positively or negatively regulate the generation of adaptive immune responses. In this review, we will discuss how myeloperoxidase, the most abundant neutrophil granule protein, plays a key role in the various functions of neutrophils in innate and adaptive immunity.


2006 ◽  
Vol 112 (1-2) ◽  
pp. 49-61 ◽  
Author(s):  
H.-H. Takamatsu ◽  
M.S. Denyer ◽  
C. Stirling ◽  
S. Cox ◽  
N. Aggarwal ◽  
...  

2016 ◽  
Author(s):  
Steven K. Lundy ◽  
Alison Gizinski ◽  
David A. Fox

The immune system is a complex network of cells and mediators that must balance the task of protecting the host from invasive threats. From a clinical perspective, many diseases and conditions have an obvious link to improper functioning of the immune system, and insufficient immune responses can lead to uncontrolled acute and chronic infections. The immune system may also be important in tumor surveillance and control, cardiovascular disease, health complications related to obesity, neuromuscular diseases, depression, and dementia. Thus, a working knowledge of the role of immunity in disease processes is becoming increasingly important in almost all aspects of clinical practice. This review provides an overview of the immune response and discusses immune cell populations and major branches of immunity, compartmentalization and specialized immune niches, antigen recognition in innate and adaptive immunity, immune tolerance toward self antigens, inflammation and innate immune responses, adaptive immune responses and helper T (Th) cell subsets, components of the immune response that are important targets of treatment in autoimmune diseases, mechanisms of action of biologics used to treat autoimmune diseases and their approved uses, and mechanisms of other drugs commonly used in the treatment of autoimmune diseases. Figures show the development of erythrocytes, platelets, lymphocytes, and other immune system cells originating from hematopoietic stem cells that first reside in the fetal liver and later migrate to the bone marrow, antigen–major histocompatibility complex recognition by T cell receptor control of T cell survival and activation, and Th cells as central determinants of the adaptive immune response toward different stimuli. Tables list cell populations involved in innate and adaptive immunity, pattern recognition receptors with known ligands, autoantibody-mediated human diseases: examples of pathogenic mechanisms, selected Food and Drug Administration–approved autoimmune disease indications for biologics, and mechanism of action of biologics used to treat autoimmune diseases.   This review contains 3 highly rendered figures, 5 tables, and 64 references.


2020 ◽  
pp. 325-336
Author(s):  
Paul Klenerman

The adaptive immune response is distinguished from the innate immune response by two main features: its capacity to respond flexibly to new, previously unencountered antigens (antigenic specificity), and its enhanced capacity to respond to previously encountered antigens (immunological memory). These two features have provided the focus for much research attention, from the time of Jenner, through Pasteur onwards. Historically, innate and adaptive immune responses have often been treated as separate, with the latter being considered more ‘advanced’ because of its flexibility. It is now clear this not the case, and in recent years the molecular basis for these phenomena has become much better understood.


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