Monomeric homologue of mammalian CD28 is expressed on chicken T cells.
A mAb recognizing a 40- to 44-kDa monomeric molecule on the surface of chicken T cells was used to screen a cDNA expression library made from Con A-stimulated chicken spleen cells. The sequence of the cDNA obtained encoded a molecule having 50% amino acid sequence identity with mammalian CD28, but the cysteine residue involved in the inter-chain bridge of the mammalian CD28 homodimer was not conserved in the chicken sequence. The molecule produced in transfected COS-7 cells was also recognized by another mAb that had previously been thought to recognize an avian homologue of CD2. The sequence data establish that this molecule is a homologue of mammalian CD28 in the strict evolutionary sense.
Young
J R
JR
Institute for Animal Health, Compton, United Kingdom.
Davison
T F
TF
Tregaskes
C A
CA
Rennie
M C
MC
Vainio
O
O
D000595:Amino Acid Sequence; D000818:Animals; D018106:CD28 Antigens / Q000145:classification* / Q000378:metabolism; D002645:Chickens / Q000276:immunology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D007178:Inbreeding; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011233:Precipitin Tests; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000276:immunology*
D018106:CD28 Antigens; D018076:DNA, Complementary