Mucosal vaccine strategies
Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald in Principles of Mucosal Immunology, 2020
In the early days of mucosal immunology, it was assumed that immune responses initiated at one mucosal site would be disseminated widely to multiple mucosal tissues. Had this common mucosal immune system existed, it could have meant that immunization by any mucosal route, such as oral immunization, could be used for inducing effective immune responses, not only in the gastrointestinal tract, but also in the airways and the urogenital tract. However, further work showed that mucosal immune responses are generally compartmentalized, not only between separate mucosal organs but also between regions from the same mucosal organ, such as the gut proximal duodenum and rectum. Irrespective of sampling mechanism, antigens taken up at the mucosal surface are transported to draining lymph nodes by DCs or are directly captured by FAE and delivered to professional APCs in the PPs and presented to CD4+ and CD8+ αβ T cells. Also, it appears that certain antigens may be processed and presented directly by epithelial cells to T cells located close to mucosal membranes, although the significance of this induction pathway is poorly understood.
Inflammation resolution and specialized pro-resolving lipid mediators in chronic rhinosinusitis
Published in Expert Review of Clinical Immunology, 2023
Peyton Z. Robinson, Daniel N. Frank, Vijay R. Ramakrishnan
A relatively simple approach to understanding CRS has proliferated in the field from early insights into disease physiology, wherein an imbalance pro-inflammatory and anti-inflammatory mechanisms is the primary problem resulting in disease, whether the factors involved are exogenous (e.g. aeroallergen) or endogenous (e.g., immune hyperresponsiveness). We must remember that inflammation is not always problematic; in fact, it is key to the maintenance of tissue homeostasis. As most CRS develops in adulthood, and can result from any number or combination of stimuli, the transition from acute inflammation to sustained chronic inflammation is really the critical problem for disease development. A key concept that has been recently developed in mucosal immunology is recognition and understanding of the active endogenous process of inflammatory resolution. Incorporating this additional pillar of resolution into a temporal understanding of inflammation in mucosal homeostasis represents a new opportunity to comprehend and treat CRS. A common dictum in CRS is that it is a chronic disease that requires long-term maintenance therapy to keep under control. Interestingly, however, some patients do achieve disease resolution and return to tissue homeostasis.
Intestinal microbes direct CX3CR1+ cells to balance intestinal immunity
Published in Gut Microbes, 2019
Myunghoo Kim, Andrea A. Hill, Wan-Jung Wu, Gretchen E. Diehl
Understanding the signals that limit intestinal inflammation and promote homeostasis are a major focus in the field of mucosal immunology. In our work, we have demonstrated that important anti-inflammatory signals are relayed through direct contact of the microbiota with the intestinal epithelium and highlight potential epithelial contribution to mucosal responses to intestinal microbes. These signals, which could be microbe or epithelial derived, are integrated by CX3CR1+ intestinal APCs. Defining these signals is an area of active investigation. CX3CR1+ APCs, through antigen presentation and cytokine secretion limit the expansion of antigen-specific Th1 cells and promote the differentiation of antigen-specific Treg cells. As the balance between T effector and Treg cells supports intestinal homeostasis, this cellular pathway likely limits inflammatory conditions such as IBD.43
Mapping Resident Immune Cells in the Murine Ocular Surface and Lacrimal Gland by Flow Cytometry
Published in Ocular Immunology and Inflammation, 2023
Baikai Ma, Yifan Zhou, Yuzhe Hu, Hongyu Duan, Zhengze Sun, Pingzhang Wang, Wei Li, Wenling Han, Hong Qi
ILCs, which do not express the type of diversified antigen receptors of T cells and B cells, are largely tissue-resident and are regarded as innate counterparts of T cells. ILCs have been given considerable attention in mucosal immunology,23 yet the composition and functions of ILCs in ocular surface was still unknown. To disclose the composition of ILCs in the conjunctiva, Lineage− immune cells were clustered into 7 subpopulations after tSNE dimensionality reduction and FlowSOM clustering based on the expression of NK1.1, CD127, IFN-γ, IL-5, RORγt, and IL-17A: IL-17A+ILC3 (4.22%), IL-17A−ILC3 (2.06%), IFN-γ+Lin− cells (3.05%), IFN-γ+ NK cells (3.86%), IFN-γ− NK cells (13.82%), ILC2 (26.21%), and undefined cells (46.77%) (Figure 3F-H). ILC1 were not found in the conjunctiva (Supplementary Fig. 7 G). Considering targeting antigens in the lineage cocktail antibodies included CD3e, Gr-1, CD11b, CD45R and TER-119, the undefined Lin− cells might contain CD11c+ cells, mast cells, and others.
Related Knowledge Centers
- Commensalism
- Gastrointestinal Tract
- Immune Tolerance
- Mucous Membrane
- Immune System
- Respiratory System
- Pathogen
- Genitourinary System
- Antigen
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