| Structural highlights
Disease
[IL2_HUMAN] Note=A chromosomal aberration involving IL2 is found in a form of T-cell acute lymphoblastic leukemia (T-ALL). Translocation t(4;16)(q26;p13) with involves TNFRSF17. [IL2RG_HUMAN] Defects in IL2RG are the cause of severe combined immunodeficiency X-linked T-cell-negative/B-cell-positive/NK-cell-negative (XSCID) [MIM:300400]; also known as agammaglobulinemia Swiss type. A form of severe combined immunodeficiency (SCID), a genetically and clinically heterogeneous group of rare congenital disorders characterized by impairment of both humoral and cell-mediated immunity, leukopenia, and low or absent antibody levels. Patients present in infancy recurrent, persistent infections by opportunistic organisms. The common characteristic of all types of SCID is absence of T-cell-mediated cellular immunity due to a defect in T-cell development.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] Defects in IL2RG are the cause of X-linked combined immunodeficiency (XCID) [MIM:312863]. XCID is a less severe form of X-linked immunodeficiency with a less severe degree of deficiency in cellular and humoral immunity than that seen in XSCID.[11] [12]
Function
[IL2_HUMAN] Produced by T-cells in response to antigenic or mitogenic stimulation, this protein is required for T-cell proliferation and other activities crucial to regulation of the immune response. Can stimulate B-cells, monocytes, lymphokine-activated killer cells, natural killer cells, and glioma cells. [IL2RG_HUMAN] Common subunit for the receptors for a variety of interleukins. [IL2RB_HUMAN] Receptor for interleukin-2. This beta subunit is involved in receptor mediated endocytosis and transduces the mitogenic signals of IL2.
Publication Abstract from PubMed
The immunostimulatory cytokine interleukin-2 (IL-2) is a growth factor for a wide range of leukocytes, including T cells and natural killer (NK) cells. Considerable effort has been invested in using IL-2 as a therapeutic agent for a variety of immune disorders ranging from AIDS to cancer. However, adverse effects have limited its use in the clinic. On activated T cells, IL-2 signals through a quaternary 'high affinity' receptor complex consisting of IL-2, IL-2Ralpha (termed CD25), IL-2Rbeta and IL-2Rgamma. Naive T cells express only a low density of IL-2Rbeta and IL-2Rgamma, and are therefore relatively insensitive to IL-2, but acquire sensitivity after CD25 expression, which captures the cytokine and presents it to IL-2Rbeta and IL-2Rgamma. Here, using in vitro evolution, we eliminated the functional requirement of IL-2 for CD25 expression by engineering an IL-2 'superkine' (also called super-2) with increased binding affinity for IL-2Rbeta. Crystal structures of the IL-2 superkine in free and receptor-bound forms showed that the evolved mutations are principally in the core of the cytokine, and molecular dynamics simulations indicated that the evolved mutations stabilized IL-2, reducing the flexibility of a helix in the IL-2Rbeta binding site, into an optimized receptor-binding conformation resembling that when bound to CD25. The evolved mutations in the IL-2 superkine recapitulated the functional role of CD25 by eliciting potent phosphorylation of STAT5 and vigorous proliferation of T cells irrespective of CD25 expression. Compared to IL-2, the IL-2 superkine induced superior expansion of cytotoxic T cells, leading to improved antitumour responses in vivo, and elicited proportionally less expansion of T regulatory cells and reduced pulmonary oedema. Collectively, we show that in vitro evolution has mimicked the functional role of CD25 in enhancing IL-2 potency and regulating target cell specificity, which has implications for immunotherapy.
Exploiting a natural conformational switch to engineer an interleukin-2 'superkine',Levin AM, Bates DL, Ring AM, Krieg C, Lin JT, Su L, Moraga I, Raeber ME, Bowman GR, Novick P, Pande VS, Fathman CG, Boyman O, Garcia KC Nature. 2012 Mar 25. doi: 10.1038/nature10975. PMID:22446627[13]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Puck JM, Deschenes SM, Porter JC, Dutra AS, Brown CJ, Willard HF, Henthorn PS. The interleukin-2 receptor gamma chain maps to Xq13.1 and is mutated in X-linked severe combined immunodeficiency, SCIDX1. Hum Mol Genet. 1993 Aug;2(8):1099-104. PMID:8401490
- ↑ DiSanto JP, Dautry-Varsat A, Certain S, Fischer A, de Saint Basile G. Interleukin-2 (IL-2) receptor gamma chain mutations in X-linked severe combined immunodeficiency disease result in the loss of high-affinity IL-2 receptor binding. Eur J Immunol. 1994 Feb;24(2):475-9. PMID:8299698
- ↑ Markiewicz S, Subtil A, Dautry-Varsat A, Fischer A, de Saint Basile G. Detection of three nonsense mutations and one missense mutation in the interleukin-2 receptor gamma chain gene in SCIDX1 that differently affect the mRNA processing. Genomics. 1994 May 1;21(1):291-3. PMID:8088810 doi:http://dx.doi.org/10.1006/geno.1994.1265
- ↑ Ishii N, Asao H, Kimura Y, Takeshita T, Nakamura M, Tsuchiya S, Konno T, Maeda M, Uchiyama T, Sugamura K. Impairment of ligand binding and growth signaling of mutant IL-2 receptor gamma-chains in patients with X-linked severe combined immunodeficiency. J Immunol. 1994 Aug 1;153(3):1310-7. PMID:8027558
- ↑ DiSanto JP, Rieux-Laucat F, Dautry-Varsat A, Fischer A, de Saint Basile G. Defective human interleukin 2 receptor gamma chain in an atypical X chromosome-linked severe combined immunodeficiency with peripheral T cells. Proc Natl Acad Sci U S A. 1994 Sep 27;91(20):9466-70. PMID:7937790
- ↑ Pepper AE, Buckley RH, Small TN, Puck JM. Two mutational hotspots in the interleukin-2 receptor gamma chain gene causing human X-linked severe combined immunodeficiency. Am J Hum Genet. 1995 Sep;57(3):564-71. PMID:7668284
- ↑ Clark PA, Lester T, Genet S, Jones AM, Hendriks R, Levinsky RJ, Kinnon C. Screening for mutations causing X-linked severe combined immunodeficiency in the IL-2R gamma chain gene by single-strand conformation polymorphism analysis. Hum Genet. 1995 Oct;96(4):427-32. PMID:7557965
- ↑ Puck JM, Pepper AE, Bedard PM, Laframboise R. Female germ line mosaicism as the origin of a unique IL-2 receptor gamma-chain mutation causing X-linked severe combined immunodeficiency. J Clin Invest. 1995 Feb;95(2):895-9. PMID:7860773 doi:http://dx.doi.org/10.1172/JCI117740
- ↑ Stephan V, Wahn V, Le Deist F, Dirksen U, Broker B, Muller-Fleckenstein I, Horneff G, Schroten H, Fischer A, de Saint Basile G. Atypical X-linked severe combined immunodeficiency due to possible spontaneous reversion of the genetic defect in T cells. N Engl J Med. 1996 Nov 21;335(21):1563-7. PMID:8900089 doi:10.1056/NEJM199611213352104
- ↑ Jones AM, Clark PA, Katz F, Genet S, McMahon C, Alterman L, Cant A, Kinnon C. B-cell-negative severe combined immunodeficiency associated with a common gamma chain mutation. Hum Genet. 1997 May;99(5):677-80. PMID:9150740
- ↑ Schmalstieg FC, Leonard WJ, Noguchi M, Berg M, Rudloff HE, Denney RM, Dave SK, Brooks EG, Goldman AS. Missense mutation in exon 7 of the common gamma chain gene causes a moderate form of X-linked combined immunodeficiency. J Clin Invest. 1995 Mar;95(3):1169-73. PMID:7883965 doi:http://dx.doi.org/10.1172/JCI117765
- ↑ Sharfe N, Shahar M, Roifman CM. An interleukin-2 receptor gamma chain mutation with normal thymus morphology. J Clin Invest. 1997 Dec 15;100(12):3036-43. PMID:9399950 doi:10.1172/JCI119858
- ↑ Levin AM, Bates DL, Ring AM, Krieg C, Lin JT, Su L, Moraga I, Raeber ME, Bowman GR, Novick P, Pande VS, Fathman CG, Boyman O, Garcia KC. Exploiting a natural conformational switch to engineer an interleukin-2 'superkine' Nature. 2012 Mar 25. doi: 10.1038/nature10975. PMID:22446627 doi:10.1038/nature10975
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