TY - JOUR
T1 - Identification of a third variable lymphocyte receptor in the lamprey
AU - Kasamatsu, Jun
AU - Sutoh, Yoichi
AU - Fugo, Kazunori
AU - Otsuka, Noriyuki
AU - Iwabuchi, Kazuya
AU - Kasahara, Masanori
PY - 2010/8/10
Y1 - 2010/8/10
N2 - Jawless vertebrates such as lamprey and hagfish lack T-cell and B-cell receptors; instead, they have unique antigen receptors known as variable lymphocyte receptors (VLRs). VLRs generate diversity by recombining highly diverse leucine-rich repeat modules and are expressed clonally on lymphocyte-like cells (LLCs). Thus far, two types of receptors, VLRA and VLRB, have been identified in lampreys and hagfish. Recent evidence indicates that VLRA and VLRB are expressed on distinct populations of LLCs that resemble T cells and B cells of jawed vertebrates, respectively. Here we identified a third VLR, designated VLRC, in the lamprey. None of the ≈100 VLRC cDNA clones subjected to sequencing had an identical sequence, indicating that VLRC can generate sufficient diversity to function as antigen receptors. Notably, the C-terminal cap of VLRC exhibits only limited diversity and has important structural differences relative to VLRA and VLRB. Single-cell PCR analysis identified LLCs that rearranged VLRC but not VLRA or VLRB, suggesting the presence of a unique population of LLCs that express only VLRC.
AB - Jawless vertebrates such as lamprey and hagfish lack T-cell and B-cell receptors; instead, they have unique antigen receptors known as variable lymphocyte receptors (VLRs). VLRs generate diversity by recombining highly diverse leucine-rich repeat modules and are expressed clonally on lymphocyte-like cells (LLCs). Thus far, two types of receptors, VLRA and VLRB, have been identified in lampreys and hagfish. Recent evidence indicates that VLRA and VLRB are expressed on distinct populations of LLCs that resemble T cells and B cells of jawed vertebrates, respectively. Here we identified a third VLR, designated VLRC, in the lamprey. None of the ≈100 VLRC cDNA clones subjected to sequencing had an identical sequence, indicating that VLRC can generate sufficient diversity to function as antigen receptors. Notably, the C-terminal cap of VLRC exhibits only limited diversity and has important structural differences relative to VLRA and VLRB. Single-cell PCR analysis identified LLCs that rearranged VLRC but not VLRA or VLRB, suggesting the presence of a unique population of LLCs that express only VLRC.
KW - Antigen receptors
KW - Immune system evolution
KW - Jawless vertebrates
KW - Leucine-rich repeats
KW - Somatic rearrangement
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U2 - 10.1073/pnas.1001910107
DO - 10.1073/pnas.1001910107
M3 - Article
C2 - 20660745
AN - SCOPUS:77956279285
VL - 107
SP - 14304
EP - 14308
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 32
ER -