Prophylactic and Therapeutic Potential of Asp f1 Epitopes in Naïve and Sensitized BALB/c Mice.
BACKGROUND
The present study examines a hypothesis that short allergen-derived peptides may shift an Aspergillus fumigatus (Afu-) specific TH2 response towards a protective TH1. Five overlapping peptides (P1-P5) derived from Asp f1, a major allergen/antigen of Afu, were evaluated for prophylactic or therapeutic efficacy in BALB/c mice.


METHODS
To evaluate the prophylactic efficacy, peptides were intranasally administered to naïve mice and challenged with Afu-allergens/antigens. For evaluation of therapeutic efficacy, the mice were sensitized with Afu-allergens/antigens followed by intranasal administration of peptides. The groups were compared for the levels of Afu-specific antibodies in sera and splenic cytokines evaluated by ELISA. Eosinophil peroxidase activity was examined in the lung cell suspensions and lung inflammation was assessed by histopathogy.


RESULTS
Peptides P1-, P2- and P3 decreased Afu-specific IgE (84.5~98.9%) and IgG antibodies (45.7~71.6%) in comparison with Afu-sensitized mice prophylactically. P1- and P2-treated ABPA mice showed decline in Afu-specific IgE (76.4~88%) and IgG antibodies (15~54%). Increased IgG2a/IgG1 and IFN-gamma/IL-4 ratios were observed. P1-P3 prophylactically and P1 therapeutically decreased IL-5 levels and eosinophil peroxidase activity. P1 decreased inflammatory cells' infiltration in lung tissue comparable to non-challenged control.


CONCLUSIONS
Asp f1-derived peptide P1, prophylactically and therapeutically administered to Balb/c mice, is effective in regulating allergic response to allergens/antigens of Afu, and may be explored for immunotherapy of allergic aspergillosis in humans.
Institute of Genomics and Integrative Biology, Mall Road, Delhi, India.
Neelkamal
N
Chaudhary
Lakshna
L
Mahajan
Taruna
T
Madan
Anil
A
Kumar
Gajendra Pratap Singh
GP
Raghava
Seturam Bandacharya
SB
Katti
Wahajul
W
Haq
Puranam Usha
PU
Sarma