The role of the thymus in integrated evolution of the recombinase-dependent adaptive immune response and the neuroendocrine system

Before being able to react against infectious non-self antigens, the immune system has to be educated in recognition and tolerance of neuroendocrine self-proteins. This sophisticated educational process takes place only in the thymus. The development of an autoimmune response directed to neuroendocrine glands has been shown to result from a thymus dysfunction in programming immunological self-tolerance to neuroendocrine-related antigens. This thymus dysfunction leads to a breakdown of immune homeostasis with an enrichment of ‘forbidden’ self-reactive T cells and a deficiency in self-antigen specific natural regulatory T cells (nTreg) in the peripheral T-lymphocyte repertoire. A large number of neuroendocrine self-antigens are expressed by the thymic epithelium, under the control of the autoimmune regulator (AIRE) gene/protein in the medulla. Based on the close homology and cross-tolerance between thymic type 1 diabetes-related self-antigens and peripheral antigens targeted in β cells by autoimmunity, a novel type of vaccination is currently developed for prevention and cure of type 1 diabetes. If this approach were found to be effective in reprogramming immunological tolerance that is absent or broken in this disease, it could pave the way for the design of negative/tolerogenic self-vaccines against other endocrine and organ-specific autoimmune disorders.Tolediab - Eurothymaid

Exploring the link between innate immune activation and thymic function by measuring sCD14 and TRECs in HIV patients living in Belgium

Microbial translocation is now viewed as a central event in the pathogenesis of chronic inflammation during HIV infection. Thymic function failure is another crucial factor involved in HIV disease progression. The goal of this study was to explore the hypothesis of potential links between microbial translocation and thymic function in HIV-1 patients living in Belgium. The extent of microbial translocation was assessed through the measurement of soluble CD14 (sCD14). T-cell receptor excision circles (sjTRECs and dβTRECs) were used as a measure of thymic function. Data were collected from 75 HIV-infected patients. Simple and complex linear regressions were done to analyze the link between these two processes. We found a statistically relevant negative correlation between thymopoiesis (sjTREC) and sCD14 level (p = 0.004). These results suggest a link between thymic function failure, microbial translocation and innate immune activation

Thymus and aging: morphological, radiological, and functional overview.

5reservedmixedRezzani R.; Nardo L.; Favero G.; Peroni M.; Rodella L.F.Rezzani, Rita; Nardo, L.; Favero, Gaia; Peroni, M.; Rodella, Luigi Fabrizi