A structural basis for antigen recognition by the T cell-like lymphocytes of sea lamprey.

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TitleA structural basis for antigen recognition by the T cell-like lymphocytes of sea lamprey.
Publication TypeJournal Article
Year of Publication2010
AuthorsDeng, L, Velikovsky, CA, Xu, G, Iyer, LM, Tasumi, S, Kerzic, MC, Flajnik, MF, Aravind, L, Pancer, Z, Mariuzza, RA
JournalProc Natl Acad Sci U S A
Volume107
Issue30
Pagination13408-13
Date Published2010 Jul 27
ISSN1091-6490
KeywordsAnimals, Binding Sites, Chickens, Epitopes, Kinetics, Lymphocytes, Models, Molecular, Muramidase, Petromyzon, Protein Binding, Protein Conformation, Protein Structure, Secondary, Protein Structure, Tertiary, Proteins, Receptors, Antigen, T-Cell, gamma-delta, T-Lymphocytes
Abstract

Adaptive immunity in jawless vertebrates is mediated by leucine-rich repeat proteins called "variable lymphocyte receptors" (VLRs). Two types of VLR (A and B) are expressed by mutually exclusive lymphocyte populations in lamprey. VLRB lymphocytes resemble the B cells of jawed vertebrates; VLRA lymphocytes are similar to T cells. We determined the structure of a high-affinity VLRA isolated from lamprey immunized with hen egg white lysozyme (HEL) in unbound and antigen-bound forms. The VLRA-HEL complex demonstrates that certain VLRAs, like gammadelta T-cell receptors (TCRs) but unlike alphabeta TCRs, can recognize antigens directly, without a requirement for processing or antigen-presenting molecules. Thus, these VLRAs feature the nanomolar affinities of antibodies, the direct recognition of unprocessed antigens of both antibodies and gammadelta TCRs, and the exclusive expression on the lymphocyte surface that is unique to alphabeta and gammadelta TCRs.

DOI10.1073/pnas.1005475107
Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID20616002
PubMed Central IDPMC2922149
Grant ListAI065610 / AI / NIAID NIH HHS / United States
AI083892 / AI / NIAID NIH HHS / United States
P30 EB009998 / EB / NIBIB NIH HHS / United States
R01 RR006603-20 / RR / NCRR NIH HHS / United States
RR006603 / RR / NCRR NIH HHS / United States