الفهرس 
Lymphatic FilariasisOnly 14 pages are availabe for public view
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Abstract
Lymphatic filariasis (LF), a mosquito-borne disease, caused by infection with thread like nematodes is targeted for elimination. Egypt was among the first countries to join the WHO efforts, and initiate a national LF elimination program in the year 2000. By 2008, >57% of LF endemic countries had started implementing mass drug administration to interrupt disease transmission. The Egyptian program, as well as LF elimination programs of other countries, is in urgent need for a diagnostic assay specific for the detection of human exposure to infective larvae (L3) as a marker of interruption of transmission. The present study was designed to apply bioinformatic tools for searching databases of filarial (B. malayi & W. bancrofti) cDNA libraries to identify L3-specific genes that possess immunogenic properties, express their recombinant proteins and characterize them. Three brugian clusters (TC7825, TC7917 and TC7969) were selected as abundant and L3-specific. Their bancroftian homologues (serpin, Spn; pyrovate dehydrogenase enzyme, PD; and the third abundant larval transcript, ALT-3, respectively) were identified. An additional bancroftian cluster coding for ALT-2 and a Novel contig were also identified. NCBI BLASTN analysis identified one EST representing each of the 5 clusters/contigs which were PCR amplified using the T3 and T7 primers. Molecular weights (MWs) of predicted expressed peptides of ALT-2, Spn, PD, ALT-3 and the Novel clone were estimated at 17.2, 23.8, 17.2, 6.3 and 8.6 kDa, respectively. The number of amino acids was estimated in the range of 36-180. Alt-2 was highly soluble (>97%), Spn moderately soluble (48.2%), PD less soluble (24.1%) and, ALT-3 and Novel insoluble (<3%). Amplicons of W. bancrofti clones were cloned and subcloned into suitable expression vectors. Based on SDS-PAGE, MWs of expressed peptides of ALT-2, ALT-3, Spn, PD and the Novel clone were estimated at 13.5, 4.0, 21.5, 16.0, and 5.5 kDa, respectively. In conclusion, the present study identified three promising abundant W. bancrofti L3-specific contiges, these codes for ALT-2, Spn and PD. Recombinant proteins of these clones are of suitable solubility and MW size for the development of antibody detection immunoassays.