Mimicry of elastin repetitive motifs by Theileria annulata sporozoite surface antigen.
Theileria annulata is an important pathogen of cattle in the tropics. The gene sequence of a sporozoite surface antigen (SPAG-1) is reported. Data is also presented demonstrating that SPAG-1 is synthesised as a large precursor. This antigen, which is a candidate for inclusion in a subunit vaccine, shows a remarkable degree of molecular mimicry to the extracellular matrix protein elastin. It contains both repetitive motifs PGVGV and VGVAPG. Immunofluorescence using a monoclonal antibody against VGVAPG confirmed that this peptide is expressed on sporozoites as predicted. The presence of VGVAPG is particularly interesting since this is the ligand for elastin receptors on a range of cell types, including macrophages/monocytes which are a major class of host target cells. It is proposed that this antigen represents the ligand whereby T. annulata recognises its host cells.
Hall
R
R
Department of Biology, University of York, UK.
Hunt
P D
PD
Carrington
M
M
Simmons
D
D
Williamson
S
S
Mecham
R P
RP
Tait
A
A
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics*; D000954:Antigens, Surface / Q000235:genetics; D001483:Base Sequence; D016054:DNA, Protozoan / Q000235:genetics; D004549:Elastin / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D016796:Theileria annulata / Q000235:genetics* / Q000254:growth & development / Q000276:immunology*
D000953:Antigens, Protozoan; D000954:Antigens, Surface; D016054:DNA, Protozoan; D015800:Protozoan Proteins; D004549:Elastin