The major dog allergens, Can f 1 and Can f 2, are salivary lipocalin proteins: cloning and immunological characterization of the recombinant forms.
Canis familiaris allergen 1 (Can f 1) and Canis familiaris allergen 2 (Can f 2) are the two major allergens present in dog dander extracts. We now report the isolation of cDNAs encoding both proteins and present their nucleotide and deduced amino acid sequences. Can f 1, produced by tongue epithelial tissue, has homology with the von Ebner's gland (VEG) protein, a salivary protein not previously thought to have allergenic properties. Can f 2, produced by tongue and parotid gland, has homology with mouse urinary protein (MUP), a known allergen. Both VEG protein and MUP are members of the lipocalin family of small ligand-binding proteins. Recombinant forms of Can f 1 and Can f 2 were produced and tested for immunoglobulin E (IgE) reactivity. Among dog-allergic subjects, 45% had IgE directed exclusively to rCan f 1, and 25% had IgE to both rCan f 1 and rCan f 2. In addition, both recombinant proteins were able to cross-link IgE and elicit histamine release from peripheral blood leucocytes in vitro. These findings confirm that Can f 1 and Can f 2 are major and minor dog allergens, respectively, and demonstrate that recombinant forms of dog allergens retain at least some IgE-binding epitopes.
Konieczny
A
A
ImmuLogic Pharmaceutical Corporation, Waltham MA 02154, USA.
Morgenstern
J P
JP
Bizinkauskas
C B
CB
Lilley
C H
CH
Brauer
A W
AW
Bond
J F
JF
Aalberse
R C
RC
Wallner
B P
BP
Kasaian
M T
MT
D000485:Allergens / Q000235:genetics* / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D052179:Antigens, Plant; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D018076:DNA, Complementary / Q000235:genetics; D004285:Dogs / Q000276:immunology*; D006636:Histamine Release; D006967:Hypersensitivity / Q000276:immunology; D007073:Immunoglobulin E / Q000378:metabolism; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins / Q000276:immunology; D012463:Saliva / Q000276:immunology*
D000485:Allergens; D052179:Antigens, Plant; D018076:DNA, Complementary; D012333:RNA, Messenger; D011994:Recombinant Proteins; C110827:allergen Can f 2; C091462:allergen Can f I; D007073:Immunoglobulin E