4YQX image
Entry Detail
PDB ID:
4YQX
Keywords:
CYTOKINE/IMMUNE SYSTEM
Title:
Mouse IL-2 Bound to JES6-1 scFv Fragment
Biological Source:
Source Organism:
Rattus norvegicus, Mus musculus
Host Organism:
Trichoplusia ni
PDB Version:
Deposition Date:
2015-03-13
Release Date:
2015-07-01
Method Details:
Experimental Method:
X-RAY DIFFRACTION
Resolution:
2.83 Å
R-Value Free:
0.20
R-Value Work:
0.16
R-Value Observed:
0.17
Space Group:
P 31 2 1
4YQX validation report
Macromolecular Entities
Protein Blast
Polymer Type:polypeptide(L)
Description:Interleukin-2
Chain IDs:C (auth: A), F (auth: M)
Chain Length:130
Number of Molecules:2
Biological Source:Mus musculus
UniProt ID:P04351 Pfam ID:PF00715
Polymer Type:polypeptide(L)
Description:JES6-1 VH domain
Chain IDs:A (auth: H), D (auth: N)
Chain Length:123
Number of Molecules:2
Biological Source:Rattus norvegicus
Polymer Type:polypeptide(L)
Description:JES6-1 VL domain
Chain IDs:B (auth: L), E (auth: O)
Chain Length:118
Number of Molecules:2
Biological Source:Rattus norvegicus
Primary Citation
Antibodies to Interleukin-2 Elicit Selective T Cell Subset Potentiation through Distinct Conformational Mechanisms.
Immunity 42 815 825 (2015)
PMID: 25992858 DOI: 10.1016/j.immuni.2015.04.015

Abstact

Interleukin-2 (IL-2) is a pleiotropic cytokine that regulates immune cell homeostasis and has been used to treat a range of disorders including cancer and autoimmune disease. IL-2 signals via interleukin-2 receptor-β (IL-2Rβ):IL-2Rγ heterodimers on cells expressing high (regulatory T cells, Treg) or low (effector cells) amounts of IL-2Rα (CD25). When complexed with IL-2, certain anti-cytokine antibodies preferentially stimulate expansion of Treg (JES6-1) or effector (S4B6) cells, offering a strategy for targeted disease therapy. We found that JES6-1 sterically blocked the IL-2:IL-2Rβ and IL-2:IL-2Rγ interactions, but also allosterically lowered the IL-2:IL-2Rα affinity through a "triggered exchange" mechanism favoring IL-2Rα(hi) Treg cells, creating a positive feedback loop for IL-2Rα(hi) cell activation. Conversely, S4B6 sterically blocked the IL-2:IL-2Rα interaction, while also conformationally stabilizing the IL-2:IL-2Rβ interaction, thus stimulating all IL-2-responsive immune cells, particularly IL-2Rβ(hi) effector cells. These insights provide a molecular blueprint for engineering selectively potentiating therapeutic antibodies.

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Primary Citation of related structures
4YQX