Hassall’s corpuscles

In a biopsy of an AIDS patient s enlarged thymus (P4), the adipose involuted thymus, with persistence of many Hassall s corpuscles, was judged to be a large lymphoid follicular hyperplasia. This follicular hyperplasia was similar to that described for lymph nodes, spleen, and other lymphoid tissues at earlier stages of human immunodeficiency virus infection, before the development of acquired immune deficiency syndrome. Human immunodeficiency virus RNA and p 24 were detected in the hyperplastic germinal centers (lymphocytes and follicular dendritic infected cells) and also in many cells that may have been either lymphocytes or epithelial cells in the interfollicular areas. 

Watarrabe N, Warrg YH, LeeHK, Ito T, Warrg YH, Cao W, Liu YJ (2005) Hassall s corpuscles irrstruct derrdritic cells to irrduce Cd4+Cd25+ regulatory T cells irr humarr thymus. Nature 436 1181—1185. 

Fig. 4. Normal thymus. This child s thymus shows the dense cortex composed predominantly of lymphocytes and the less dense medulla with fewer lymphcoytes. Note the Hassall s corpuscle. X40. [From Rosai and Levine (1976). With permission of the Armed Forces Institute of Pathology.]...

As age involution progresses, lymphatic tissue gradually decreases, the cortex thins, Hassall s corpuscles become more prominent, and fatty replacement of the organ ensues. Many of the Hassall s corpuscles become calcified or cystic. Some of the epithelial cells may acquire a spiral shape. In... 

Decrease demonstrated over the first 10 years of life, but not with further aging. primarily found in Hassall s corpuscles. 

High levels of TGF-Ps are present in actively differentiating tissue, e.g. cartilage canals, osteocytes, Hassall s corpuscle in the thymus, bone marrow, hematopoietic stem cells, the highest levels being found in blood platelets. It is noteworthy that subcutaneous administration of TGF-P promotes the deposition of... 

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