Initial Project Idea

Properdin acts as an amplifier of complement activation in the fluid phase.
Deficiency of properdin leads to a measurable reduction in complement
activation in the fluid-phase due to a decrease in the half-life of the
complement converting enzyme complexes. In addition, however, macrophages
and dendritic cells, which are deficient of properdin, appear to behave
differently from the wildtype on a cellular level: they produce more TNF-a
after stimulation with LPS and differ in their numbers of intracellular
Listeria monocytogenes. Current work aims to characterise the role of
properdin in the cellular response to infection with Mycobacterium marinum,
a category 2 model microorganism for M. tuberculosis.

At the moment, the envisaged project is thought to analyse these sets of
experiments: 

Cells (such as splenic macrophages, bone marrow derived dendritic cells or
mast cells) will be prepared from properdin deficient and wildtype mice.
They will be infected with M.marinum using normoxic and hypoxic conditions.
Cells will be lysed after infection to determine intracellular viable counts
(CFU) and supernatants will be analysed for TNF-a bioactivity using L929
indicator cells.   

Non-adherent cells such as murine mast cells may be analysed by flow
cytometry for the abundance of associated and internalised, labelled
M.marinum. Macrophage cell lines such as J774 and RAW can be used to assess
the time dependent host cell response by analysing gene expression.