Abstracts (complete list) - Wissenschaft Online

Alexia Nass, Hans-Willi Mittruecker, Alf Hamann, Jochen Huehn
Transfer of in vivo operating inflammation-specific Tregs does
not interfere with the host´s response against bacterial
infection
Regulatory T cells (Tregs) play an essential role in regulating inflammatory immune
responses in vivo. In several models it has been shown that Tregs can suppress both
the initiation of immune responses as well as ongoing inflammatory reactions. Little
knowledge exists about the therapeutic use of antigen-specific Tregs to suppress
unwanted immune reactions, while allowing an effective immune response against
invading pathogens at the same time. Here we used a Th1-mediated delayed-type
hypersensitivity (DTH) model for an inflammatory response and analyzed whether a
defined subpopulation of antigen-specific ? +
E Tregs would be able to suppress the DTH
response in the context of a contemporaneous systemic infection with Listeria
monocytogenes. Furthermore, we determined if the presence of high numbers of
inflammation-specific Tregs would influence the immune response against L.
monocytogenes, which mainly takes place within the spleen and liver. ? +
E Tregs turned
out to be potent suppressors of the local inflammation irrespective of the presence or
absence of a systemic bacterial infection. In addition mice adoptively transferred with
antigen-specific Tregs still established an effective immune response against L.
monocytogenes compared to animals not receiving Tregs. Together, our findings
provide evidence that adoptive transfer of antigen-specific Tregs effectively suppresses
inflammatory reactions even in the context of a systemic L. monocytogenes infection
without impairing the host´s pathogen-specific immune response.