Identification of an antigen from the sheep scab mite, Psoroptes ovis, homologous with house dust mite group I allergens.
Infestation of sheep with the ectoparasitic mite Psoroptes ovis, results in a severe allergic dermatitis. Currently, little is known about the allergens/antigens that stimulate the allergic response. We have isolated an 836-bp cDNA from a P. ovis cDNA library which displays strong homology to cysteine proteases and, in particular, to the group I house dust mite allergens Der p 1, Der f 1 and Eur m 1. The cDNA was expressed in Escherchia coli, fused to a hexahistidine tag and the recombinant protein (Pso o 1) purified using a nickel-affinity column. The recombinant Pso o 1 was tested for recognition by immunoglobulin (Ig)G and IgE in serum from P. ovis naïve and P. ovis infested sheep. Using Western blots, both classes of antibody to Pso o 1 were detected in postinfestation serum. In enzyme-linked immunosorbent assays, a pronounced IgG-antibody response to Pso o 1 was detected in five of five sheep 3 weeks postinfestation. The IgE-antibody response to whole mite extract was poor in four of five animals. However, a marked IgE response occurred in the fifth animal, and IgE anti Pso o 1 was detected in the serum.
Lee
A J
AJ
School of Biology, The University of Leeds, Leeds, UK. a.j.lee@leeds.ac.uk
Machell
J
J
Van Den Broek
A H M
AH
Nisbet
A J
AJ
Miller
H R P
HR
Isaac
R E
RE
Huntley
J F
JF
D000485:Allergens / Q000235:genetics / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000941:Antigens / Q000235:genetics / Q000276:immunology*; D039741:Antigens, Dermatophagoides / Q000276:immunology; D001483:Base Sequence; D003001:Cloning, Molecular; D007073:Immunoglobulin E / Q000032:analysis / Q000276:immunology; D007074:Immunoglobulin G / Q000032:analysis / Q000276:immunology; D008924:Mite Infestations / Q000175:diagnosis / Q000276:immunology*; D008969:Molecular Sequence Data; D040042:Psoroptidae / Q000166:cytology / Q000276:immunology* / Q000472:pathogenicity; D039981:Pyroglyphidae / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D012756:Sheep
D000485:Allergens; D000941:Antigens; D039741:Antigens, Dermatophagoides; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D007073:Immunoglobulin E