Hornet venom allergen antigen 5, Dol m 5: its T-cell epitopes in mice and its antigenic cross-reactivity with a mammalian testis protein.
BACKGROUND
A major venom allergen of white-faced hornet (Dolichovespula maculata) is antigen 5, Dol m 5. It is a 204-residue protein having 23% to 35% sequence identity with several proteins from diverse sources. The biologic function of antigen 5 and its sequence-related proteins is not known.


OBJECTIVE
This study was done to delineate the T-cell epitopes of Dol m 5 and to test their cross-reactivity with a sequence-related mouse testis protein, tpx.


METHODS
T-cell epitope mapping and cross-reactivity were studied with 15- or 20-residue peptides by their stimulation of spleen cells from mice immunized with recombinant Dol m 5 or tpx fragments.


RESULTS
Three of 20 peptides studied were found to represent major T-cell epitopes of Dol m 5, being recognized by five or all of six mouse strains tested. One major epitope peptide, residue 176-195, showed cross-reactivity in BALB/c mice with the homologous antigen 5s from yellow jackets and wasps, as well as with mouse tpx. The cross-reactivity of Dol m 5 and mouse tpx is not reciprocal because spleen cells from tpx-immunized mice were stimulated by the hornet peptide, but cells from Dol m 5-immunized mice were not stimulated by the corresponding tpx peptides.


CONCLUSIONS
Cross-reactivity of vespid antigen 5 and mouse tpx may be of importance in insect allergy because human and mouse testis proteins are highly homologous.
King
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Rockefeller University, New York, USA.
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D000485:Allergens / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006023:Glycoproteins / Q000276:immunology*; D006183:H-2 Antigens / Q000235:genetics; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000276:immunology*; D013737:Testis / Q000276:immunology*; D014862:Wasp Venoms / Q000276:immunology*
D000485:Allergens; D000939:Epitopes; D006023:Glycoproteins; D006183:H-2 Antigens; D010446:Peptide Fragments; D014862:Wasp Venoms; C040583:white-faced hornet venom antigen 5