====== Interleukin-2 ======
[[Interleukin]]-2 (IL-2) is an [[interleukin]], a type of cytokine signaling molecule in the immune system. It is a 15,5 - 16 kDa protein that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the body's natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes.
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[[Interleukin-2]](IL-2): has shown minimal activity in brain Mets, and trials have usually excluded patients with untreated or uncontrolled brain Mets due to risk of [[cerebral edema]] and hemorrhage from the capillary leak.
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Based on previous finding that IL-2 strongly elevated the expression of the checkpoint molecule [[Tim-3]] in Treg cells, we examined the effect of IL-2 in the function of Treg cells from IA patients. External IL-2 significantly improved the proliferation of Treg cells, increased the expression of CTLA-4 and LAG-3, and enhanced Treg-mediated suppression of conventional T cell (Tconv) proliferation. Importantly, compared to the Tim-3- Treg cells, the Tim-3+ Treg cells presented comparable proliferation capacity, but significantly greater expressions of CTLA-4 and LAG-3 and significantly higher capacity to suppress Tconv proliferation. In addition, blocking Tim-3 abrogated IL-2-mediated enhancement of Tim-3+ Treg cells. We then investigated the IL-2 level in IA patients, and found that although IA patients and healthy controls presented similar serum IL-2 concentration, the concentrations of IL-1β and TNF-α were significantly higher in IA patients than in healthy controls, signaling a relative reduction in IL-2 abundance. Together, we found that IL-2 could significantly enhance the function of Treg cells from IA patients in a Tim-3-dependent manner
((Zhang HF, Liang GB, Zhao MG, Zhao GF, Luo YH. Regulatory T cells demonstrate
significantly increased functions following stimulation with IL-2 in a
Tim-3-dependent manner in intracranial aneurysms. Int Immunopharmacol. 2018 Oct
23;65:342-347. doi: 10.1016/j.intimp.2018.10.029. [Epub ahead of print] PubMed
PMID: 30366277.
)).