Jt. Harty et D. White, A knockout approach to understanding CD8(+) cell effector mechanisms in adaptive immunity to Listeria monocytogenes, IMMUNOBIOL, 201(2), 1999, pp. 196-204
In the described experimental approach, we use an attenuated LM strain to e
voke LM specific CD8(+) T cell responses. In this fashion, we can immunize
immunocompromised gene knockout mice, that would succumb to low level infec
tion with virulent LM. Wc then generate antigen matched, LM-specific CD8(+)
T cell lines from wild-type and gene knockout mice, and compare their capa
city to provide immunity to LM infection in vivo. To date, our results demo
nstrate that CD8(+) T cell-derived IFN-gamma and TNF are not required effec
tor functions. Perforin deficiency has an impact on CD8(+) T cell immunity
but our studies provide strong evidence for the existence of perforin indep
endent pathways of CD8(+) T cell immunity to LM. To assess the potential fo
r redundancy in effector mechanisms, we have generated mice deficient in bo
th perforin and IFN-gamma and are developing mice deficient in perforin and
TNF By removing the major CD8(+) T cell effector mechanisms, singly and in
combination, we will eventually determine whether immunity to LM can be pr
ovided by redundant effector pathways or if novel effector mechanisms exist
beyond our current knowledge. The generation of MHC matched, single and do
uble knockout mice, will also aid in continuing studies to analyze the role
of these molecules in resistance to in vivo infection.