3RTQ

Structure of the mouse CD1d-HS44-iNKT TCR complex

Summary for 3RTQ

• Entry DOI: 10.2210/pdb3rtq/pdb
• Descriptor: Antigen-presenting glycoprotein CD1d1, Beta-2-microglobulin, Valpha14 (mouse variable domain, human constant domain), ... (9 entities in total)
• Functional Keywords: antigen presentation, glycolipid, nkt cells, immune system
• Biological source: Mus musculus (mouse); More
• Total number of polymer chains: 4
• Total formula weight: 96572.21

Authors

Yu, E.D.,Zajonc, D.M. (deposition date: 2011-05-03, release date: 2012-02-22, Last modification date: 2024-10-16)

Primary citation

Kerzerho, J.,Yu, E.D.,Barra, C.M.,Alari-Pahisa, E.,Girardi, E.,Harrak, Y.,Lauzurica, P.,Llebaria, A.,Zajonc, D.M.,Akbari, O.,Castano, A.R.
Structural and functional characterization of a novel nonglycosidic type I NKT agonist with immunomodulatory properties.
J.Immunol., 188:2254-2265, 2012

PubMed Abstract: Activation of type I NKT (iNKT) cells by CD1d-presented agonists is a potent immunotherapeutic tool. α-Galactosylceramide (α-GalCer) is the prototypic agonist, but its excessive potency with simultaneous production of both pro- and anti-inflammatory cytokines hampers its potential therapeutic use. In search for novel agonists, we have analyzed the structure and function of HS44, a synthetic aminocyclitolic ceramide analog designed to avoid unrestrained iNKT cell activation. HS44 is a weaker agonist compared with α-GalCer in vitro, although in vivo it induces robust IFN-γ production, and highly reduced but still functional Th2 response. The characteristic cytokine storm produced upon α-GalCer activation was not induced. Consequently, HS44 induced a very efficient iNKT cell-dependent antitumoral response in B16 animal model. In addition, intranasal administration showed the capacity to induce lung inflammation and airway hyperreactivity, a cardinal asthma feature. Thus, HS44 is able to elicit functional Th1 or Th2 responses. Structural studies show that HS44 binds to CD1d with the same conformation as α-GalCer. The TCR binds to HS44 similarly as α-GalCer, but forms less contacts, thus explaining its weaker TCR affinity and, consequently, its weaker recognition by iNKT cells. The ability of this compound to activate an efficient, but not massive, tailored functional immune response makes it an attractive reagent for immune manipulation.

PubMed: 22301545
DOI: 10.4049/jimmunol.1103049

Experimental method

X-RAY DIFFRACTION (2.8 Å)