Mast Cells: Bridging Host-Microorganism Interactions

Editorial

31 January 2022

Editorial: Mast Cells: Bridging Host-Microorganism Interactions

Rommel Chacón-Salinas

Anna Di Nardo

and

Soman N. Abraham

2,256 views

0 citations

Editors

Rommel Chacon-Salinas

Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional

Anna Di Nardo

University of California, San Diego

Soman Ninan Abraham

Duke University

Impact

Review

10 September 2021

Mast Cell Modulation of B Cell Responses: An Under-Appreciated Partnership in Host Defence

Alejandro M. Palma

, 1 more and

Jean S. Marshall

Evidence of cytokine and receptor-ligand interaction between mast cells and B cells has been depicted according to the following color scheme: red for evidence found in rodents, blue for evidence found in humans, and green for rodents and humans. Interaction between mast cells and B cells can occur at mucosal sites as well as at lymphoid and vascular tissues (although less frequently than at the mucosa). This is achieved by a broad array of cytokines (mainly type 2 cytokines, IL-10, IL-6, and IL-33), membrane-bound receptors and ligands (e.g., CD40/CD40L), and granule products such as histamine and proteases. These interactions can promote B cell proliferation, survival, class-switch to IgA or IgE, among other impacts. In addition, exosomes from both mast cells and B cells may be involved in communication between these cells. (Figure was prepared using BioRender).

Mast cells are well known to be activated via cross-linking of immunoglobulins bound to surface receptors. They are also recognized as key initiators and regulators of both innate and adaptive immune responses against pathogens, especially in the skin and mucosal surfaces. Substantial attention has been given to the role of mast cells in regulating T cell function either directly or indirectly through actions on dendritic cells. In contrast, the ability of mast cells to modify B cell responses has been less explored. Several lines of evidence suggest that mast cells can greatly modify B cell generation and activities. Mast cells co-localise with B cells in many tissue settings and produce substantial amounts of cytokines, such as IL-6, with profound impacts on B cell development, class-switch recombination events, and subsequent antibody production. Mast cells have also been suggested to modulate the development and functions of regulatory B cells. In this review, we discuss the critical impacts of mast cells on B cells using information from both clinical and laboratory studies and consider the implications of these findings on the host response to infections.

10,743 views

21 citations

Laboratory (lab) mice maintained in ultra-hygienic, specific pathogen-free (SPF) conditions profoundly lack lung parenchymal mast cells, in contrast to the rich presence of mast cells in human lungs (not depicted). Interestingly, free-living wild house mice are found to express lung parenchymal mast cells. Support for an environmental impact on the development of lung mast cells in these mice comes from the fact that mast cells do appear in the lung tissues of ‘naturalized’ lab mice bred in a semi-natural environment with farm-derived bedding materials.

Original Research

27 September 2021

Mast Cells Are Identified in the Lung Parenchyma of Wild Mice, Which Can Be Recapitulated in Naturalized Laboratory Mice

Yu-Wen Yeh

, 4 more and

Zou Xiang

5,628 views

13 citations

Peritoneal cell smear stained with toluidine blue. Mast cells are metachromatically stained purple with toluidine blue. Obj. 40x, scale bar = 50 μm; insets, obj. 100x, scale bar = 10 μm. (1) Loading of Fcγ-receptors of MC with IgG antibodies (hyperimmune serum of mice). (2) The load of MC that bound Ab using influenza viruses. (3) Degranulation and histamine release.

Original Research

14 July 2021

Study of Antibody-Dependent Reactions of Mast Cells In Vitro and in a Model of Severe Influenza Infection in Mice

Andrey Mamontov

, 4 more and

Yulia Desheva

2,656 views

1 citations

Original Research

23 June 2021

Murepavadin, a Small Molecule Host Defense Peptide Mimetic, Activates Mast Cells via MRGPRX2 and MrgprB2

Aetas Amponnawarat

, 1 more and

Hydar Ali

5,009 views

19 citations

CDC monomers released from bacteria bind through their D4 domain to plasma membrane (PM) microdomains called lipid rafts enriched in cholesterol, GPI-anchored proteins, and Src family kinases. PM-bound monomers form dimers that polymerize into pre-pore structures containing 30 to 50 CDC monomers. In this process, CDCs induce aggregation of lipid raft components leading to formation of signaling assemblies called signalosome. The signalosomes are capable to initiate cell activation events. Individual CDCs in the pre-pore structure undergo conformational rearrangement and formation of membrane-spanning β-strands, leading to concerted membrane insertion and formation of the pore with approximately 25 nm in diameter. Formation of the transmembrane pore results in influx of Ca2+ into the cytoplasm and efflux of K+, other small molecules (e.g., ATP), and proteins through the plasma membrane. These processes trigger various cell responses involved in repairing the plasma membrane and activating innate and acquired immunity.

Review

23 June 2021

Molecular Mechanisms of Mast Cell Activation by Cholesterol-Dependent Cytolysins

Lubica Draberova

, 1 more and

Petr Draber

5,407 views

5 citations

Review

15 June 2021

Responses of Mast Cells to Pathogens: Beneficial and Detrimental Roles

Mariela Jiménez

, 4 more and

Eva Salinas

Mast cells (MCs) are strategically located in tissues close to the external environment, being one of the first immune cells to interact with invading pathogens. They are long living effector cells equipped with different receptors that allow microbial recognition. Once activated, MCs release numerous biologically active mediators in the site of pathogen contact, which induce vascular endothelium modification, inflammation development and extracellular matrix remodeling. Efficient and direct antimicrobial mechanisms of MCs involve phagocytosis with oxidative and non-oxidative microbial destruction, extracellular trap formation, and the release of antimicrobial substances. MCs also contribute to host defense through the attraction and activation of phagocytic and inflammatory cells, shaping the innate and adaptive immune responses. However, as part of their response to pathogens and under an impaired, sustained, or systemic activation, MCs may contribute to tissue damage. This review will focus on the current knowledge about direct and indirect contribution of MCs to pathogen clearance. Antimicrobial mechanisms of MCs are addressed with special attention to signaling pathways involved and molecular weapons implicated. The role of MCs in a dysregulated host response that can increase morbidity and mortality is also reviewed and discussed, highlighting the complexity of MCs biology in the context of host-pathogen interactions.

11,461 views

54 citations