Khosrow Aghaiypour Kolyani
Razi Vaccine and Serum Research Institute, Iran
Title: A novel marvelous evolutionary detection: lack of a large 2888 bp intron region within HA03 gene from Hyalomma anatolicum anatolicum, unlike its commercial recombinant anti-tick orthologue, Bm86, from Boophilus microplus
Biography
Biography: Khosrow Aghaiypour Kolyani
Abstract
Hyalomma anatolicum anatolicum (H. a. anatolicum) as the most widespread tick species in Iran and other parts of the middle east is responsible for the hugely serious economic losses in livestock industry. This study was conducted to investigate genetic variability of the Bm86 orthologous gene, HA03, in five different Iranian H. a. anatolicum isolates including Kordan, Qom, Boinzahra, Lorestan and Bushehr. Likewise, a number of in silico analyses were performed in order to predict the possible impact of the amino acid substitutions on antigenicity of the protein. Comparative sequence analysis of the Bm86 orthologous gene sequence among five tick isolates allowed for identification of four non-synonymous single nucleotide polymorphisms (SNPs) including c.995A > C, c.1150G > C, c.1151A > C/T and c.1152G > T which would result in p.Asn 332 Thr, p.Glu 384 Leu and p.Glu 384 Ala substitutions. As much as antigenicity is concerned, based on our in silico studies, the amino acid position 384 was located in a putative antigenic peptide of the protein. Our subsequent physicochemical and structural analyses illustrated that two out of three amino acid substitutions including p.Glu 384 Leu and p.Glu 384 Ala considerably influenced the 3-dimensional structure and physicochemical properties of HA03 protein including hydrophobicity, amphiphilicity and net charge; thus, they might affect the antigen-antibody reaction and consequently immunogenicity of the antigen. In conclusion, it is a rational measure not only to replace Bm86 with HA03 in formulation of the recombinant anti-tick vaccine, but also to combine various antigens extracted from different isolates of the tick species.