Articles: regulatory-t-lymphocytes.
-
Journal of critical care · Dec 2013
Complement C3 depletion links to the expansion of regulatory T cells and compromises T-cell immunity in human abdominal sepsis: A prospective pilot study.
Complement depletion commonly occurred in septic patients, but this problem was often underestimated during the treatment process. This study was designed to determine the association between complement depletion and T-cell immunosuppression. ⋯ Complement C3 depletion was found to be linked to the expansion of Tregs during abdominal sepsis. Such depletion and associated immunosuppression should be paid close attention in the critical care.
-
Recent clinical trials show Lactobacillus rhamnosus GG (LGG) administration in critical illness has the potential to reduce nosocomial infections and improve clinical outcome. However, the mechanism(s) of LGG-mediated benefit following illness and injury remain elusive. ⋯ These data demonstrate that early administration of LGG improves outcome following P. aeruginosa-induced pneumonia. An effect of LGG on Treg cells may play a role in this protection.
-
J. Korean Med. Sci. · Dec 2013
Role of regulatory T cells in transferable immunological tolerance to bone marrow donor in murine mixed chimerism model.
Constructing a bone marrow chimera prior to graft transplantation can induce donor-specific immune tolerance. Mixed chimerism containing hematopoietic cells of both recipient- and donor-origin has advantages attributed from low dose of total body irradiation. In this study, we explored the mechanism of mixed chimerism supplemented with depletion of Natural Killer cells. ⋯ Furthermore, the induction of transferable immunological tolerance was confirmed by adoptive transfer and subsequent acceptance of C57BL/6 skin graft (n = 4). CD4(+)FoxP3(+) regulatory T cells were increased in the recipient compartment of the mixed chimera (19.2% → 33.8%). This suggests that regulatory T cells may be therapeutically used for the induction of graft-specific tolerance by mixed chimerism.
-
Many species of bacteria use quorum sensing to sense the amount of secreted metabolites and to adapt their growth according to their population density. We asked whether similar mechanisms would operate in lymphocyte homeostasis. We investigated the regulation of the size of interleukin-2 (IL-2)-producing CD4(+) T cell (IL-2p) pool using different IL-2 reporter mice. ⋯ Administration of IL-2 decreases the number of cells of the IL-2p cell subset and, pertinently, abrogates their ability to produce IL-2 upon in vivo cognate stimulation, while increasing T reg cell numbers. We propose that control of the IL-2p cell numbers occurs via a quorum sensing-like feedback loop where the produced IL-2 is sensed by both the activated CD4(+) T cell pool and by T reg cells, which reciprocally regulate cells of the IL-2p cell subset. In conclusion, IL-2 acts as a self-regulatory circuit integrating the homeostasis of activated and T reg cells as CD4(+) T cells restrain their growth by monitoring IL-2 levels, thereby preventing uncontrolled responses and autoimmunity.
-
Anti-tumor necrosis factor α therapeutics has the potential to alleviate pulmonary fibrosis. However, the systemic administration of anti-tumor necrosis factor α agents has brought about contradictory results and frequent adverse effects, such as infections, immunogenicity and malignancies, amongst others. In the present study, we attempted the local administration of tumor necrosis factor α antisense oligonucleotide and evaluated the treatment effects on pulmonary fibrosis in a bleomycin-induced pulmonary fibrosis mouse model. ⋯ These findings demonstrate that local administration of tumor necrosis factor α antisense oligonucleotide contributes to anti-fibrotic action via a sustained up-regulated level of regulatory T cells, which inhibits T(H)2-biased responses, pro-fibrotic mediator production and extracellular matrix deposition, with no systemic immunosupression associated with systemically induced regulatory T cells.