Current projects in the Bowdish lab include:

1) The role of the macrophage scavenger receptors in host defence

The two major class A scavenger receptors are called SRA and MARCO, which have high levels of homology but sharply opposing patterns of regulation. SRA is constitutively expressed on macrophages whereas MARCO expression is inducible and is upregulated in response to toll like receptor agonists. The primary role of SRA appears to be clearance of modified host proteins and lipids while MARCO is associated with the response to infectious disease. Mice defective in expression of either MARCO or SRA are immunocompromised in multiple models of infection. Preliminary data indicates that these receptors may be especially important in host defence towards the pulmonary pathogens Streptococcus pneumoniae and Mycobacterium tuberculosis. Ongoing work is being performed to determine the role of these receptors in binding, recognition and signalling in response to bacterial components and recruitment and motility of leukocytes. Student positions are currently filled, accepting applications from post-doctoral fellows with independent funding.

2) Understanding the complex interplay between commensals and resident pathogens in the upper respiratory tract

Very little is known about the macrophages and antigen presenting cells of the upper respiratory tract interact with commensals and resident pathogens of the upper respiratory tract, or indeed even the composition of the microflora of the upper respiratory tract. Our work involves characterizing recognition and responses to colonization and infection in the upper respiratory tract and immunophenotyping the resident and recruited cells to the upper respiratory tract.  Student and post-doctoral fellows with independent funding will be considered.

3) Discovering age associated changes in innate immunity that correlate with susceptibility to infection.

Macrophage receptor expression is dynamic and depends on factors in the local environment (e.g. the cytokine milieu, cell-cell interactions, exposure to pathogen associated molecular patterns) and change with age. Very little is known about how monocyte/macrophage functions change as we age and how this predisposes us to disease. We aim to determine, on the populatione level, whether age associated changes in moncyte/macrophage receptor expression and function contribute to susceptibility of the elderly to infectious disease. Manipulation of expression is useful in design of adjuvants and immunomodulatory agents that this population so urgently requires. Student positions are currently filled, accepting applications from post-doctoral fellows with independent funding.