Identification of a novel cytokine-like transcript differentially expressed in avian gammadelta T cells.
Chicken represents a species with a high frequency of gammadelta T cells in peripheral blood, suggesting an important function. To elucidate the genes specific for the avian gammadelta T cells, the suppression subtractive hybridization (SSH) between gammadelta and alphabeta T cells was used. The SSH library, which was successfully enriched for the TCR gamma and delta (both V and C region) sequences, provided gammadelta T-cell-specific genes, including, for example, the ribosomal proteins, signaling and structural molecules, and molecules related to transcription and translation. Among these genes, a clone named KK34 was shown to match the PFAM profile for IL-5 and to have 19.5% amino acid identity to the human interleukin 5 protein. Clone KK34 had lower sequence homology, from 5.4% to 15.6%, to other short-chain four-helix bundle superfamily members IL-3, IL-4, IL-13 and GM-CSF. The hydrophobic signal peptide sequence and the presence of cysteines needed for the interchain disulfide bonds were found to be conserved between clone KK34 and mammalian IL-5 proteins. Clone KK34 transcript expression was studied by RT-PCR, Northern blotting and in situ hybridization and it was confirmed to be expressed in avian gammadelta T cells. We propose that this clone, KK34, may represent the first nonmammalian IL-5, supporting the findings that gammadelta T cells are important in the development of allergy.
Koskela
Kimmo
K
Department of Medical Microbiology, Turku Graduate School of Biomedical Sciences, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland. kimmo.koskela@utu.fi
Kohonen
Pekka
P
Salminen
Heli
H
Uchida
Tatsuya
T
Buerstedde
Jean-Marie
JM
Lassila
Olli
O
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001853:Bone Marrow / Q000276:immunology / Q000502:physiology; D002645:Chickens; D016207:Cytokines / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D018793:Interleukin-13 / Q000235:genetics / Q000378:metabolism; D007377:Interleukin-3 / Q000235:genetics / Q000378:metabolism; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D015848:Interleukin-5 / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013154:Spleen / Q000276:immunology / Q000502:physiology; D013382:Subtraction Technique; D013601:T-Lymphocytes / Q000378:metabolism*; D013950:Thymus Gland / Q000276:immunology / Q000502:physiology
D016207:Cytokines; D018793:Interleukin-13; D007377:Interleukin-3; D015848:Interleukin-5; D016692:Receptors, Antigen, T-Cell, gamma-delta; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor