ReviewRoles of mast cells and basophils in innate and acquired immunity
Introduction
Mast cells and basophils share a number of similarities but they also differ in many aspects of natural history and function. Both cell types express the αβγ2 form of the high-affinity receptor for IgE (FcεRI) on their surface and both mast cells and basophils can be activated to secrete diverse preformed mediators and lipid mediators (the latter are synthesized de novo), as well as cytokines, after crosslinking of FcεRI-bound IgE with bivalent or multivalent antigen. However, recent work shows that mast cells can also play a critical role in innate immunity to bacterial infection and that mast cells and basophils can be activated by viral proteins. This review will discuss recent advances in our understanding of the effector and the potential immunoregulatory functions of mast cells and basophils during innate or acquired immune responses.
Mast cells and basophils not only are important effector cells in acute IgE-associated allergic reactions but also may contribute significantly to the expression of aspects of acquired immune responses that develop over hours (e.g. late-phase reactions [LPRs]) or days to weeks (e.g. chronic allergic inflammation) [1], [2], [3], [4], [5] (Fig. 1). Mast cells and basophils may also mediate immunoregulatory functions, both through their ability to produce certain cytokines and by other mechanisms [1], [2], [3], [4], [5], [6]. Before we discuss the potential roles of mast cells and basophils in acquired or innate immunity, we will provide some background on the biology of these two cell types.
Section snippets
Basic mast cell and basophil biology
Both mast cells and basophils are derived from CD34+ hematopoietic progenitor cells, such as those present in adult bone marrow; however, mast cells and basophils differ in natural history. Whereas basophils (like other granulocytes) typically mature in the bone marrow and then circulate in the peripheral blood, from where they can then be recruited into the tissues, mature mast cells typically do not circulate in the blood but complete their differentiation in vascularized tissues [1]. Under
Genetic approaches in studies of mast cell or basophil function
A particularly useful approach to study mast cell function in vivo is to employ genetically mast-cell-deficient WBB6F1-KitW/KitW-v mice (W/Wv mice), which lack expression of a functional c-kit receptor due to spontaneous mutations in both copies of c-kit [9], [17]. The mast cell activity in these W/Wv mice can be selectively reconstituted by the adoptive transfer of genetically compatible, in-vitro-derived mast cells; such mast cells can be derived in at least two ways: firstly, from the bone
Mast cells and basophils in acquired immunity
The best-studied forms of acquired immunity involving mast cells and basophils are examples of IgE-associated immune responses. The aggregation of FcεRIs that are occupied by IgE (e.g. following binding of IgE to multivalent antigens) is sufficient for initiating downstream signaling pathways that activate the cells to degranulate and also induce the de novo synthesis and secretion of lipid mediators and cytokines [20], [21], [22].
In vitro and in vivo studies in both mice and humans have
IgE-associated immune responses
Studies in ‘mast cell knockin’ mice show that mast cells are essential for virtually all of the augmented vascular permeability and tissue swelling that are associated with IgE-dependent passive cutaneous anaphylaxis reactions [1]. Several findings indicate that mast cells are critical for the immediate phase of IgE-associated ‘Type I’ reactions in humans as well [1], [2], [3], [4], [5], [31]. However, in many allergic patients, the immediate reaction to cutaneous antigenic challenge is
Host defense against parasites
Parasite infections are often associated with increased levels of circulating basophils and eosinophils, markedly increased serum levels of IgE (and therefore enhanced expression of FcεRI on basophils and mast cells) and increased numbers of mast cells and/or basophils in the affected tissues [1], [2], [3], [4], [5].
Although it has been difficult to prove that individual components of IgE-associated immune responses to parasites are truly essential for the expression of host immunity, W/Wv mice
Mast cells and basophils in innate immunity
‘Mast cell knockin’ mice were used to show that mast cells can represent a central component of innate host defense against certain bacterial infections, that the recruitment of circulating leukocytes with bactericidal properties is dependent on mast cells and that TNF-α is one important element of this response [10], [45], [46]. Whereas certain bacterial products—including lipopolysaccharide and at least one fimbrial adhesin [47]—can directly induce the release of some mast cell products,
Additional pathways for eliciting mast cell and/or basophil function during immune responses
Human basophils have been shown to respond to stimulation with immobilized secretory IgA (sIgA) by releasing both histamine and LTC4; however, this only occurs if the cells had first been primed by pretreatment with IL-3, IL-5 or GM-CSF [49]. Since IgA is the most abundant immunoglobulin isotype in mucosal secretions, this finding suggests that sIgA may contribute to basophil activation during immune responses at mucosal sites [49].
Protein L of Pneumococcus magnus and Protein A of
Conclusions
It seems very likely that mast cells and basophils express complex—and partially overlapping—roles in acquired and innate immunity (Fig. 4); these roles include both effector cell and, potentially, immunoregulatory activities.
Studies in mast-cell-reconstituted, genetically mast-cell-deficient mice—and correlative analyses in humans—indicate that mast cells can contribute to leukocyte infiltration, tissue remodeling and long-term functional changes in the context of IgE-associated acquired
Acknowledgements
Some of the work reviewed herein was supported by United States Public Health Service grants CA 72074, AI 23990 and AI 41995 (project 1), by Deutsche Forschungsgemeinschaft grant WE 2300/1 and/or by AMGEN Inc. SJG consults for AMGEN Inc. under terms that are in accordance with Stanford University conflict-of-interest policies.
References and recommended reading
Papers of particular interest, published within the annual period of review, have been highlighted as:
of special interest
of outstanding interest
References (55)
- et al.
The diverse potential effector and immunoregulatory roles of mast cells in allergic disease
J Allergy Clin Immunol
(2000) - et al.
Unravelling the mast cell dilemma: culprit or victim of its generosity?
Immunol Today
(1997) - et al.
Interleukin-3 is a differentiation factor for human basophils
Blood
(1989) - et al.
Mast cells as sentinels of innate immunity
Curr Opin Immunol
(1999) - et al.
Signal transduction by Fc receptors: the FcεRI case
Immunol Today
(1993) - et al.
A dominant role for mast cell Fc receptors in the Arthus reaction
Immunity
(1996) - et al.
Mast cell-dependent neutrophil and mononuclear cell recruitment in immunoglobulin E-induced gastric reactions in mice
Gastroenterology
(1996) - et al.
Proteoglycans as modulators of growth factor activities
Cell
(1991) - et al.
Basophils in skin reactions of mast cell-deficient mice infested with Dermacentor variabilis
Int J Parasitol
(1990) - et al.
Direct evidence of mast cell involvement in Clostridium difficile toxin A-induced enteritis in mice
Gastroenterology
(1998)
Mast cells
Physiol Rev
Mast cells and basophils
Curr Opin Hematol
Role for interleukin-3 in mast-cell and basophil development and in immunity to parasites
Nature
The kit ligand, stem cell factor
Adv Immunol
Human peripheral blood basophils primed by interleukin 3 (IL-3) produce IL-4 in response to immunoglobulin E receptor stimulation
J Exp Med
Secretion of IL-4 from human basophils. The relationship between IL-4 mRNA and protein in resting and stimulated basophils
J Immunol
IL-13 released by and localized in human basophils
J Immunol
Heparin is essential for the storage of specific granule proteases in mast cells
Nature
Abnormal mast cells in mice deficient in a heparin-synthesizing enzyme
Nature
Identification of basophilic cells that express mast cell granule proteases in the peripheral blood of asthma, allergy, and drug-reactive patients
J Immunol
Molecular bases of dominant negative and loss of function mutations at the murine c-kit/white spotting locus: W37, Wv, W41 and W
EMBO J
In vivo immunological function of mast cells derived from embryonic stem cells: an approach for the rapid analysis of even embryonic lethal mutations in adult mice in vivo
Proc Natl Acad Sci USA
The c-kit ligand, stem cell factor, can enhance innate immunity through effects on mast cells
J Exp Med
The high-affinity IgE receptor (FcεRI): from physiology to pathology
Annu Rev Immunol
Signalling through the high-affinity IgE receptor FcεRI
Nature
Cited by (292)
Mouse hygiene status–A tale of two environments for mast cells and allergy
2024, Allergology InternationalThe basophil: From control of immunity to control of leukemias
2022, Annales Pharmaceutiques FrancaisesLeukotriene D<inf>4</inf> role in allergic asthma pathogenesis from cellular and therapeutic perspectives
2020, Life SciencesCitation Excerpt :c-KIT receptors belong to the tyrosine kinase receptor family that dimerize or oligomerize upon ligand binding leading to the cross phosphorylation of the intrinsic tyrosine domains and downstream activation of multiple signaling pathways [54]. MCs mediate their role in allergic diseases such as asthma through the activation of their surface-expressed high-affinity receptors for IgE (FcεRI) [55]. In asthma, MCs are sensitized by binding of IgE to the FcεR1.
Genetic inhibition of NFATC2 attenuates asparaginase hypersensitivity in mice
2020, Blood Advances