Identification of T-cell epitopes of Lol p 9, a major allergen of ryegrass (Lolium perenne) pollen.
T-cell recognition of Lol p 9, a major allergen of ryegrass pollen, was investigated by using a T-cell line and T-cell clones generated from the peripheral blood of an atopic donor. The T-cell line reacted with purified Lol p 9, as well as with crude ryegrass pollen extract, but failed to cross-react with Bermuda grass pollen extract. All of six T-cell clones generated from this line proliferated in response to Lol p 9. Epitope mapping was carried out with a panel of 34 overlapping synthetic peptides, which spanned the entire sequence of the Lol p 9 12R isoform. The T-cell line responded to two of the peptides, Lol p 9 (105-116) and Lol p 9 (193-204), whereas reactivity with one or other of these peptides was shown by five T-cell clones. These two peptides contained sequences consistent with motifs previously reported for major histocompatibility complex class II-restricted peptides. HLA antibody blocking studies showed that presentation of peptide Lol p 9 (105-116) to one T-cell clone was HLA-DR-restricted; this clone expressed a T helper cell phenotype (CD3+, CD4+) and the T-cell receptor alpha beta. The identification of immunodominant T-cell epitope(s) on allergens is essential for devising safer and more effective immunotherapy strategies, which can interrupt the chain of events leading to allergic disease.
Blaher
B
B
Department of Pathology and Immunology, Monash University, Prahran, Victoria, Australia.
Suphioglu
C
C
Knox
R B
RB
Singh
M B
MB
McCluskey
J
J
Rolland
J M
JM
D000485:Allergens / Q000032:analysis*; D017951:Antigen Presentation; D052179:Antigens, Plant; D002460:Cell Line; D002999:Clone Cells; D018604:Epitope Mapping; D000939:Epitopes / Q000032:analysis*; D006801:Humans; D016130:Immunophenotyping; D008129:Lolium / Q000737:chemistry / Q000276:immunology*; D008285:Major Histocompatibility Complex / Q000276:immunology; D008297:Male; D010940:Plant Proteins / Q000032:analysis* / Q000276:immunology*; D011058:Pollen / Q000737:chemistry / Q000276:immunology*; D013601:T-Lymphocytes / Q000737:chemistry / Q000145:classification / Q000276:immunology*
D000485:Allergens; D052179:Antigens, Plant; D000939:Epitopes; C084941:Lol p V protein, Lolium perenne; D010940:Plant Proteins