ehsan arefian department of virology, faculty of medical sciences, tarbiat modares university, tehran, iran taravat bamdad department of virology, faculty of medical sciences, tarbiat modares university, tehran, iran masoud soleimani department of hematology, faculty of medical sciences, tarbiat modares university, tehran, iran amir atashi department of stem cell biology, stem cell technology research center, tehran, iran parviz fallah department of molecular biology and genetic engineering, stem cell technology research center, tehran, iran