A major goal is to understand the mechanisms of T cell
exhaustion during chronic infections. Prior work
studying CD8 T cell responses during chronic viral
infections has demonstrated that virus-specific CD8 T
cells often lose effector functions and fail to acquire
key memory T cell properties such as homeostatic
proliferation (i.e. become exhausted). Using a variety
of approaches including multiparameter flow cytometry,
systems biology and global gene expression profiling and
genetically modified mice we are defining cellular and
transcriptional pathways involved in T cell exhaustion
and normal memory T cell differentiation.
Some of areas of considerable
current interest include inhibitory
receptors (e.g. PD-1, LAG-3), transcription factors and
inflammatory pathways. In addition, we are examining how
co-infection with two pathogens can impact T cell
memory.
Others are
investigating the mechanisms of T cell mediated
protective immunity to influenza virus, enteric viral
infection and age-related changes in T cell immunity in
both mice and humans.