Bioinformatics and immunologic investigation on B and T cell epitopes of Cur l 3, a major allergen of Curvularia lunata.
The knowledge on epitopes of proteins can help in devising new therapeutic modalities for allergic disorders. In the present study, five B (P1-P5) and five T cell (P6-P10) epitopes were predicted in silico based on sequence homology model of Cur l 3, a major allergen of Curvularia lunata. Peptides (epitopes) were synthesized and assessed for biological activity by ELISA, competitive ELISA, lymphoproliferation and cytokine profiling using Curvularia allergic patients' sera. B cell peptides showed higher IgE binding by ELISA than T cell epitopes except P6. Peptides P1-P6 achieved EC(50) at 100 ng, whereas P7-P10 required 10 mug in inhibition assays. Peripheral blood mononuclear cells from Curvularia allergic patients (n = 20) showed higher lymphoproliferation for T cell epitopes than B cell epitopes except P6 confirming the properties of B and T cell prediction. The supernatant from these patients show highest interleukin-4 release on stimulation with P6 followed by B cell peptides. P4 and P6 together identified 35/37 of Curvularia positive patients by skin tests. In summary, experimental analysis confirmed in silico predicted epitopes containing important antigenic regions of Cur l 3. P6, a predicted T cell epitope, showed the presence of a cryptic B cell epitope. Peptides P4 and P6 have potential for clinical application. The approach used here is relevant and may be used to delineate epitopes of other proteins.
Sharma
Vidhu
V
Allergy and Immunology Section, Institute of Genomics and Integrative Biology (CSIR), and V. P. Chest Institute, Delhi University Campus, Delhi, India.
Singh
Bhanu P
BP
Gaur
Shailendra N
SN
Pasha
Santosh
S
Arora
Naveen
N
D000485:Allergens / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D020816:Amino Acid Motifs / Q000276:immunology; D000908:Antibodies, Fungal / Q000097:blood; D001203:Ascomycota / Q000235:genetics / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D019295:Computational Biology; D003198:Computer Simulation; D045304:Cytochromes c / Q000737:chemistry / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D005656:Fungal Proteins / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007073:Immunoglobulin E / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D011485:Protein Binding
D000485:Allergens; D000908:Antibodies, Fungal; D016207:Cytokines; D018985:Epitopes, B-Lymphocyte; D018984:Epitopes, T-Lymphocyte; D005656:Fungal Proteins; D010446:Peptide Fragments; D007073:Immunoglobulin E; D045304:Cytochromes c