Phage-displayed Bet mim 1, a mimotope of the major birch pollen allergen Bet v 1, induces B cell responses to the natural antigen using bystander T cell help.
OBJECTIVE
In previous studies we have generated mimotopes of Bet v 1, the major birch pollen allergen, by biopannings of phage-display random peptide libraries. In the present study, we analysed the humoral and cellular immune response to Bet v 1-mimotopes.


METHODS
The mimotope CFPYCYPSESA, designated Bet mim 1, was used for intraperitoneal immunizations of BALB/c mice in phage-displayed form. For examination of the humoral immune response, enzyme-linked immunosorbent assay (ELISA) experiments were applied. Stimulation capacities were investigated in cultured mouse splenocytes and in humoral Bet v 1-specific T cell clones.


RESULTS
We demonstrated that the Bet mim 1-induced murine antibody response against Bet v 1 was predominated by the IgG1 isotype. In these mice only the phage-displayed mimotopes, but neither the allergen nor the synthetic Bet mim 1-mimotopes were able to stimulate proliferation of cultured splenocytes. Using Bet v 1-specific T cell clones of allergic patients, phage-displayed and synthetic mimotopes were unable to stimulate T cell proliferation. Moreover, tolerance induction to Bet v 1 in mice by intranasal administration of Bet mim 1-phages or Bet mim 1-peptide failed.


CONCLUSIONS
Taking these results together, our data indicate that Bet mim 1 mimics a Bet v 1-epitope on the B cell but not on the T cell level. We suggest that the phage itself is responsible for the recruitment of T cells providing bystander help in the formation of a mimotope-specific humoral response.
Schöll
I
I
Department of Pathophysiology, University of Vienna, Austria.
Wiedermann
U
U
Förster-Waldl
E
E
Ganglberger
E
E
Baier
K
K
Boltz-Nitulescu
G
G
Scheiner
O
O
Ebner
C
C
Jensen-Jarolim
E
E
D000485:Allergens / Q000276:immunology*; D000818:Animals; D052179:Antigens, Plant; D001402:B-Lymphocytes / Q000276:immunology*; D001435:Bacteriophages; D040761:Biomimetic Materials; D002455:Cell Division; D002478:Cells, Cultured; D005260:Female; D007108:Immune Tolerance; D007114:Immunization; D007074:Immunoglobulin G / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010940:Plant Proteins / Q000276:immunology*; D013154:Spleen; D013601:T-Lymphocytes / Q000276:immunology*
D000485:Allergens; D052179:Antigens, Plant; D007074:Immunoglobulin G; D010940:Plant Proteins; C061312:Bet v 1 allergen, Betula