Carrier-bound Alt a 1 peptides without allergenic activity for vaccination against Alternaria alternata allergy.
BACKGROUND
The mould Alternaria alternata is a major elicitor of allergic asthma. Diagnosis and specific immunotherapy (SIT) of Alternaria allergy are often limited by the insufficient quality of natural mould extracts.


OBJECTIVE
To investigate whether recombinant Alt a 1 can be used for reliable diagnosis of Alternaria alternata allergy and to develop a safe, non-allergenic vaccine for SIT of Alternaria allergy.


METHODS
The qualitative sensitization profile of 80 Alternaria-allergic patients from Austria and Italy was investigated using an allergen micro-array and the amount of Alternaria-specific IgE directed to rAlt a 1 was quantified by ImmunoCAP measurements. Peptides spanning regions of predicted high surface accessibility of Alt a 1 were synthesized and tested for IgE reactivity and allergenic activity, using sera and basophils from allergic patients. Carrier-bound peptides were studied for their ability to induce IgG antibodies in rabbits which recognize Alt a 1 and inhibit allergic patients' IgE reactivity to Alt a 1.


RESULTS
rAlt a 1 allowed diagnosis of Alternaria allergy in all tested patients, bound the vast majority (i.e. >95%) of Alternaria-specific IgE and elicited basophil activation already at a concentration of 0.1 ng/mL. Four non-allergenic peptides were synthesized which, after coupling to the carrier protein keyhole limpet hemocyanin, induced Alt a 1-specific IgG and inhibited allergic patients' IgE binding to Alt a 1.


CONCLUSIONS
rAlt a 1 is a highly allergenic molecule allowing sensitive diagnosis of Alternaria allergy. Carrier-bound non-allergenic Alt a 1 peptides are candidates for safe SIT of Alternaria allergy.
Christian Doppler Laboratory for Allergy Research, Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
T E
TE
Twaroch
M
M
Focke
K
K
Fleischmann
N
N
Balic
C
C
Lupinek
K
K
Blatt
R
R
Ferrara
A
A
Mari
C
C
Ebner
P
P
Valent
S
S
Spitzauer
I
I
Swoboda
R
R
Valenta
D000293:Adolescent; D000328:Adult; D000528:Alternaria / Q000276:immunology*; D000818:Animals; D000908:Antibodies, Fungal / Q000097:blood / Q000276:immunology / Q000378:metabolism; D000918:Antibody Specificity / Q000276:immunology; D000946:Antigens, Fungal / Q000737:chemistry / Q000276:immunology*; D002648:Child; D005260:Female; D005657:Fungal Vaccines / Q000276:immunology*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D006967:Hypersensitivity / Q000175:diagnosis* / Q000517:prevention & control*; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology / Q000378:metabolism; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008297:Male; D010455:Peptides / Q000276:immunology*; D011485:Protein Binding / Q000276:immunology; D017510:Protein Folding; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D011817:Rabbits; D055815:Young Adult
C474845:ALTB1 protein, Alternaria brassicicola; D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D005657:Fungal Vaccines; D007074:Immunoglobulin G; D010455:Peptides; D007073:Immunoglobulin E