Prophylactic and Therapeutic Potential of Asp f1 Epitopes in Naive 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 naive 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. CONCLUSION: 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.

Association of SP-D, MBL and I-NOS genetic variants with pulmonary tuberculosis.

Background: Pulmonary tuberculosis is caused by Mycobacterium tuberculosis . It is a multifactorial disease with both host as well as pathogen factors contributing to susceptibility and protection from the disease. Various reports have highlighted important roles of lung surfactant protein D (SP-D), mannan-binding lectin (MBL) and I-NOS in innate immune defense against M. tuberculosis Aims : The present study investigated the role of polymorphisms in three candidate genes encoding Lung surfactant protein D, Mannan binding lectin and Inducible Nitric oxide synthase, in susceptibility and protection to pulmonary tuberculosis. Settings and Design : A case-control association study of SNP's in lung surfactant protein D (SP-D), mannan-binding lectin (MBL) and I-NOS with pulmonary tuberculosis in Indian population was carried out. This involved sequencing of all the coding exons of lung surfactant protein D (SP-D) , while, exon 1 (collagen region) and exon 4 (carbohydrate recognition domain) of mannan-binding lectin (MBL) and exons 2, 8 and 16 of I-NOS and their flanking intronic regions for single nucleotide polymorphisms in DNA samples isolated from 30 pulmonary tuberculosis patients and 30 controls of Indian population. Statistical analysis: Various allele frequencies were calculated using online two by two table (home.clara.net/sisa/). Odds ratio and P values were calculated at 95% confidence interval (CI). Results : A total of fourteen single nucleotide polymorphisms (5 in SP-D , 5 in MBL and 4 in I-NOS ) were observed of which four (G459A SP-D , G274T I-NOS , G1011A and T357G MBL ) have not been reported earlier. Four single nucleotide polymorphisms viz. G459A of exon 7 of SP-D ( P =0.00, odds ratio (OR) = 4.96, 2.18 P = 0.00 or= 3.85 1.66 P =0.00 or=4.04, 2.20< OR<7.42) and G274T of intron 16 of I-NOS ( P =0.00 or=4.46, 2.40 Conclusion: The present study has led to identification of 4 SNP's in SP-D , MBL and I-NOS associated with pulmonary tuberculosis in Indian population.