Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Deletion of human metapneumovirus M2-2 increases mutation frequency and attenuates growth in hamsters | Virology Journal BioMed Central Research Deletion of human metapneumovirus M2-2 increases mutation frequency and attenuates growth in hamsters Jeanne H Schickli Jasmine Kaur Mia MacPhail Jeanne M Guzzetta Richard R Spaete and Roderick S Tang Address Research Dept MedImmune Mountain View CA 94043 USA Email Jeanne H Schickli - Schicklij@ Jasmine Kaur-Kaurj@ Mia MacPhail - Macphailm@ Jeanne M Guzzetta - Guzzettaj@ Richard R Spaete - Spaeter@ Roderick S Tang - Tangr@ Corresponding author Open Access Published 3 June 2008 Received 16 March 2008 Virology Journal 2008 5 69 doi 1743-422X-5-69 Accepted 3 June 2008 This article is available from http content 5 1 69 2008 Schickli et al licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Human metapneumovirus hMPV infection can cause acute lower respiratory tract illness in infants the immunocompromised and the elderly. Currently there are no licensed preventative measures for hMPV infections. Using a variant of hMPV NL 1 00 that does not require trypsin supplementation for growth in tissue culture we deleted the M2-2 gene and evaluated the replication of rhMPV AM2-2 virus in vitro and in vivo. Results In vitro studies showed that the ablation of M2-2 increased the propensity for insertion of U nucleotides in poly-U tracts of the genomic RNA. In addition viral transcription was up-regulated although the level of genomic RNA remained comparable to rhMPV. Thus deletion of M2-2 alters the ratio between hMPV genome copies and transcripts. In vivo rhMPV AM2-2 was attenuated compared to rhMPV in the lungs and nasal turbinates of hamsters. Hamsters immunized with one dose of
