Targeting and hematopoietic suppression of human CD34+ cells by measles virus.

The major cause of mortality in measles is generalized suppression of cell-mediated immunity that persists following virus clearance and results in secondary infections. The mechanisms contributing to this long-term immunosuppression are not clear. Herein we present evidence that measles virus (MV) disrupts hematopoiesis by infecting human CD34+ cells and human bone marrow stroma. MV infection does not affect the hematopoietic capability of hematopoietic stem cells (HSCs) directly; rather, the infection impairs the ability of stroma to support development of HSCs. These results suggest that MV-mediated defects in hematopoiesis contribute to the long-term immunosuppression seen in measles.