christine hartoonian department of pharmaceutical biotechnology and biotechnology research center, faculty of pharmacy, tehran university of medical sciences, tehran, ir iran; department of virology, pasteur institute of iran, tehran, ir iran zargham sepehrizadeh department of pharmaceutical biotechnology and biotechnology research center, faculty of pharmacy, tehran university of medical sciences, tehran, ir iran; department of pharmaceutical biotechnology and biotechnology research center, faculty of pharmacy, tehran university of medical sciences, tehran, ir iran. tel: +98-2164122301, fax: + 98-2166461178, e-mail: kayhan azadmanesh, department of virology, pasteur institute of iran, tehran, ir iran. tel/fax: +98-2166496682 mojtaba tabatabai yazdi department of pharmaceutical biotechnology and biotechnology research center, faculty of pharmacy, tehran university of medical sciences, tehran, ir iran yong suk jang departments of molecular biology and bioactive material sciences, institute for molecular biology and genetics, chonbuk national university, jeonju, korea lida langroudi department of virology, pasteur institute of iran, tehran, ir iran parisa amir kalvanagh department of virology, pasteur institute of iran, tehran, ir iran; department of immunology, faculty of medical sciences, tarbiat modaress university, tehran, ir iran