Sequence and structural analysis of feline interleukin-5 cDNA

Am J Vet Res. 1998 Oct;59(10):1263-9.


Objective: To clone and characterize the cDNA encoding feline interleukin-5 (IL-5) cDNA and the 170 basepairs (bp) of the 5' flanking region of the feline IL-5 gene.

Sample population: Blood mononuclear cells from a healthy cat.

Procedures: Cells were cultured, stimulated for 48 hours with concanavalin A, and harvested for RNA and DNA isolation. Recovered RNA was used in northern blot and reverse transcription-polymerase chain reaction analyses. Resulting cDNA was used for rapid amplification of 3' cDNA ends, dideoxy chain termination sequencing, and primer extension analysis.

Results: Full length cDNA was 838 bp, including a 402-bp open reading frame that encoded a precursor protein of 134 amino acids including a putative peptide signal of 19 residues. Homologies of the nucleotide and derived protein sequences between feline and human IL-5 cDNA were 72 and 71%, respectively. There also was homology between the human and predicted feline cytokines at amino acid positions that are critical for IL-5 receptor binding and signal transduction. The 5' flanking region of the feline gene was homologous to corresponding regions of the human (88%) and murine (72%) genes, and included putative transcriptional regulatory elements.

Conclusions and clinical relevance: Identification of feline IL-5 cDNA is an important step toward a detailed, fully comprehensive characterization of the mechanisms that may be operative in the pathogenesis of eosinophilic disorders in cats. The striking homology between the human and feline IL-5 genes suggests that cats can be used as animal models for human diseases characterized by eosinophil infiltration of tissues.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites / genetics
  • Blotting, Northern / veterinary
  • Blotting, Southern
  • Cats / genetics*
  • Cats / immunology
  • Cells, Cultured
  • Cloning, Molecular
  • DNA, Complementary / chemistry*
  • Gene Expression
  • Humans
  • Interleukin-5 / genetics*
  • Leukocytes, Mononuclear / chemistry
  • Mice
  • Molecular Sequence Data
  • Open Reading Frames
  • Operator Regions, Genetic / genetics
  • Polymerase Chain Reaction / veterinary
  • Sequence Homology, Nucleic Acid
  • Signal Transduction


  • DNA, Complementary
  • Interleukin-5

Associated data

  • GENBANK/AF025436