Functional CD1d and/or NKT cell invariant chain transcript in horse, pig, African elephant and guinea pig, but not in ruminants.
CD1d-restricted invariant natural killer T cells (NKT cells) have been well characterized in humans and mice, but it is unknown whether they are present in other species. Here we describe the invariant TCR alpha chain and the full length CD1d transcript of pig and horse. Molecular modeling predicts that porcine (po) invariant TCR alpha chain/poCD1d/alpha-GalCer and equine (eq) invariant TCR alpha chain/eqCD1d/alpha-GalCer form complexes that are highly homologous to the human complex. Since a prerequisite for the presence of NKT cells is the expression of CD1d protein, we performed searches for CD1D genes and CD1d transcripts in multiple species. Previously, cattle and guinea pig have been suggested to lack CD1D genes. The CD1D genes of European taurine cattle (Bos taurus) are known to be pseudogenes because of disrupting mutations in the start codon and in the donor splice site of the first intron. Here we show that the same mutations are found in six other ruminants: African buffalo, sheep, bushbuck, bongo, N'Dama cattle, and roe deer. In contrast, intact CD1d transcripts were found in guinea pig, African elephant, horse, rabbit, and pig. Despite the discovery of a highly homologous NKT/CD1d system in pig and horse, our data suggest that functional CD1D and CD1d-restricted NKT cells are not universally present in mammals.
Looringh van Beeck
Frank A
FA
Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University Utrecht, Utrecht, The Netherlands.
Reinink
Peter
P
Hermsen
Roel
R
Zajonc
Dirk M
DM
Laven
Marielle J
MJ
Fun
Axel
A
Troskie
Milana
M
Schoemaker
Nico J
NJ
Morar
Darshana
D
Lenstra
Johannes A
JA
Vervelde
Lonneke
L
Rutten
Victor P M G
VP
van Eden
Willem
W
Van Rhijn
Ildiko
I
D000595:Amino Acid Sequence; D000818:Animals; D055610:Antigens, CD1d / Q000235:genetics* / Q000378:metabolism; D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics* / Q000378:metabolism; D002415:Cats; D002417:Cattle; D004285:Dogs; D004606:Elephants / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D006168:Guinea Pigs; D000949:Histocompatibility Antigens Class II / Q000235:genetics* / Q000378:metabolism; D006736:Horses / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D055611:Natural Killer T-Cells / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D012418:Ruminants / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D013552:Swine / Q000235:genetics* / Q000276:immunology / Q000378:metabolism
D055610:Antigens, CD1d; D000944:Antigens, Differentiation, B-Lymphocyte; D000949:Histocompatibility Antigens Class II; D012333:RNA, Messenger; C045084:invariant chain