Mouse CD1 is distinct from and co-exists with TL in the same thymus.
Human CD1 antigens have a similar tissue distribution and overall structure to (mouse) TL. However recent data from human CD1 suggest that the mouse homologue is not TL. Since no human TL has been conclusively demonstrated, we have analysed the murine CD1 genes. Two closely linked genes are found in a tail to tail orientation and the limited polymorphism found shows that, as in humans, the CD1 genes are not linked to the MHC. Both genes are found to be equally transcribed in the thymus, but differentially in other cell types. The expression in liver, especially, does not parallel CD1 in humans. This demonstrates conclusively that CD1 and TL are distinct and can co-exist in the same thymus. It is paradoxical that despite the structural similarity between mouse and human CD1, the tissue distribution of human CD1 is closer to TL. The possibility of a functional convergence between MHC molecules and CD1 is discussed.
Bradbury
A
A
MRC Laboratory of Molecular Biology, Cambridge, UK.
Belt
K T
KT
Neri
T M
TM
Milstein
C
C
Calabi
F
F
D000595:Amino Acid Sequence; D000818:Animals; D018949:Antigens, CD1; D000943:Antigens, Differentiation / Q000235:genetics*; D015152:Blotting, Northern; D002460:Cell Line; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D008285:Major Histocompatibility Complex; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013950:Thymus Gland / Q000502:physiology*
D018949:Antigens, CD1; D000943:Antigens, Differentiation; D008562:Membrane Glycoproteins; C028388:thymus-leukemia antigens