TY - JOUR
T1 - On the origins of adaptive immunity
T2 - innate immune receptors join the tale
AU - van den Berg, Timo K
AU - Yoder, Jeffrey A
AU - Litman, Gary W
PY - 2004/1
Y1 - 2004/1
N2 - Among members of the Ig superfamily (IgSF), antigen receptors have the unique capacity to rearrange their variable domains, thereby creating an extensive repertoire for antigen recognition. It is assumed that antigen receptors evolved from a non-rearranging IgSF member by insertion of a transposable element. Although the nature of this predecessor is unknown, two multigene families of innate immune receptors that bear a close structural resemblance to antigen receptor chains have been identified in mammals and bony fish, respectively: signal-regulatory proteins (SIRPs) and novel immune-type receptors (NITRs). Members of both families encode V-set Ig domains with a typical antigen receptor-like joining (J) motif and possess the potential to signal through immunoreceptor tyrosine-based inhibition motifs (ITIMs) or immunoreceptor tyrosine-based activation motifs (ITAMs). By analogy to the T-cell receptor (TCR) and certain innate receptors [e.g. killer cell inhibitory receptors (KIRs)] that recognize MHC molecules, SIRP members regulate immune function by interaction with broadly expressed 'self' ligands. We propose the existence of an evolutionary and functional link between innate and adaptive immune receptors that sheds light on the nature of the antigen receptor predecessor(s).
AB - Among members of the Ig superfamily (IgSF), antigen receptors have the unique capacity to rearrange their variable domains, thereby creating an extensive repertoire for antigen recognition. It is assumed that antigen receptors evolved from a non-rearranging IgSF member by insertion of a transposable element. Although the nature of this predecessor is unknown, two multigene families of innate immune receptors that bear a close structural resemblance to antigen receptor chains have been identified in mammals and bony fish, respectively: signal-regulatory proteins (SIRPs) and novel immune-type receptors (NITRs). Members of both families encode V-set Ig domains with a typical antigen receptor-like joining (J) motif and possess the potential to signal through immunoreceptor tyrosine-based inhibition motifs (ITIMs) or immunoreceptor tyrosine-based activation motifs (ITAMs). By analogy to the T-cell receptor (TCR) and certain innate receptors [e.g. killer cell inhibitory receptors (KIRs)] that recognize MHC molecules, SIRP members regulate immune function by interaction with broadly expressed 'self' ligands. We propose the existence of an evolutionary and functional link between innate and adaptive immune receptors that sheds light on the nature of the antigen receptor predecessor(s).
KW - Amino Acid Sequence
KW - Animals
KW - Antigens, Differentiation
KW - Evolution, Molecular
KW - Humans
KW - Immunoglobulins/immunology
KW - Membrane Glycoproteins/immunology
KW - Multigene Family
KW - Neural Cell Adhesion Molecule L1/immunology
KW - Receptors, Antigen
KW - Receptors, Antigen, T-Cell/immunology
KW - Receptors, Immunologic
KW - Sequence Homology, Amino Acid
M3 - Review article
C2 - 14698279
VL - 25
SP - 11
EP - 16
JO - Trends in Immunology
JF - Trends in Immunology
SN - 1471-4906
IS - 1
ER -