AtenuaÃ§Ã£o do vÃrus vacinal do sarampo: InfecÃ§Ã£o sub-Ã³tima do tecido linfÃ¡tico e alteraÃ§Ã£o do tropismo
The mechanisms of measles virus (MV) vaccine attenuation are insufficiently characterized. Because the vaccine strain can enter cells through CD46 in addition to the primary MV receptor signaling lymphocyte activation molecule (SLAM, CD150), we asked whether and how its tropism is altered. In human tonsillar tissue, this vaccine strain infectsnaive (CD45RA+ CD62L+) T lymphocytes, which express SLAM very infrequently, with much higher efficiency than do wild-type strains. By contrast, it infects B-lymphocytes, macrophages, and NK cells with significantly lower efficiencies than those of wild-type strains. Infection levels by wild-type strains correlate with the frequency of SLAMexpression, and are highest in B-cells, which are 40-55% infected. SLAM-expressing Tcells are more readily infected by all MV strains than are SLAM-expressing B-cells. Thus, vaccine attenuation may be caused by tropism alteration in combination with suboptimalreplication.
Advisor:Silvana Maria Eloi Santos; Heliane Brant Machado Freire; Marcus Vinicius Melo de Andrade; Gustavo EustÃ¡quio Brito Alvim de Melo; AndrÃ©a Teixeira de Carvalho
School:Universidade Federal de Minas Gerais
Source Type:Master's Thesis
Keywords:ntÃgeno CD4 DeCS
Date of Publication:03/30/2008