Abstract
Granulocyte macrophage-colony stimulating factor (GM-CSF) is a hematopoietic growth factor involved in differentiation, survival and activation of myeloid and non-myeloid cells with important implications for lung antibacterial immunity. We here assessed the therapeutic effect of single or repetitive pulmonary adenoviral vector-mediated delivery of GM-CSF (AdGM-CSF) on antimycobacterial immunity in M. bovis BCG infected mice. Single exposure of M. bovis BCG infected mice to AdGM-CSF accelerated inflammatory leukocyte recruitment to the bronchoalveolar compartment and lung draining lymph nodes along with slightly but significantly reduced mycobacterial loads up until day 21, relative to control vector-exposed mice. Repetitive exposure of mice to AdGM-CSF substantially enhanced lung leukocyte recruitment and antimycobacterial effector cell activation and led to significantly reduced mycobacterial loads in lung distal airspaces of mice. Together, these data demonstrates the immunomodulatory efficacy of GM-CSF exposure in BCG-infected mice, which may prove useful as future adjuvant treatment of tuberculosis in humans.
- Copyright ©the authors 2016