Hassall's corpuscles
| Hassall's corpuscles | |
|---|---|
 Micrograph of a thymic corpuscle. H&E stain. | |
| Anatomical terminology |
Hassall's corpuscles (or thymic corpuscles (bodies)) are structures found in the medulla of the human thymus, formed from eosinophilic type VI epithelial reticular cells arranged concentrically. They are named for Arthur Hill Hassall, who discovered them in 1849.
The function of Hassall's corpuscles is currently unclear, and the absence of this structure in the murine thymus has restricted mechanistic dissection. It is known that Hassall's corpuscles are a potent source of the cytokine TSLP. In vitro, TSLP directs the maturation of dendritic cells, and increases the ability of dendritic cells to convert naive thymocytes to a Foxp3+ regulatory T cell lineage.[1][2] It is unknown if this is the physiological function of Hassall's corpuscles in vivo.
In the past decade, Hassall's corpuscles were again in the focus of pathologists and clinicians, as the researchers found tissue-specific self-antigens in corpuscles and revealed their role in the pathogenesis of diseases such as type 1 diabetes , rheumatoid arthritis , multiple sclerosis, autoimmune thyroiditis , Goodpasture's syndrome [ and others. They also discovered that Hassall's corpuscles synthesize chemokines affecting different cell populations in thymic medulla . Despite this, the information on the relationship between Hassall's corpuscles with other cell types of thymic medulla (dendritic, myoid, neuroendocrine cells, thymocytes, macrophages, eosinophils, etc.) remains insufficient and often contradictory . Mechanisms of these relationships and their functional significance are still unclear . The lack of such data does not allow forming a holistic, systemic view of the differentiation processes in the thymus.
Hassall's corpuscles vary in size with diameters from 20 to more than 100μm, and tend to grow larger with age.[3]
References
- ^ * Watanabe N, Wang Y, Lee H, Ito T, Wang Y, Cao W, Liu Y (2005). "Hassall's corpuscles instruct dendritic cells to induce CD4+CD25+ regulatory T cells in human thymus". Nature. 436 (7054): 1181–5. doi:10.1038/nature03886. PMID 16121185.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ "Old mystery solved, revealing origin of regulatory T cells that 'police' and protect the body"
- ^ Geneser, Finn (1999). Histologi. Munksgaard Danmark. ISBN 87-628-0137-6.
External links
- synd/1912 at Who Named It?
- UIUC Histology Subject 1247
- Histology at KUMC lymphoid-lymph03 "Hassall's Corpuscles"
- Histology image: 61_05 at the University of Oklahoma Health Sciences Center - "Thymus"
- Histology image: 07407loa – Histology Learning System at Boston University - "Lymphoid Tissues and Organs: thymus, Hassall's corpuscles"
- Beloveshkin, A. G. (2014). Systemic organization of Hassall’s corpuscles.
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