Abstracts (complete list) - Wissenschaft Online

Dimitra Kotsougiani, Birgit Prior, Gertrud Maria Hänsch, Christof Wagner
Activation of T lymphocytes in bacterial infection: production
of interferon 4gamma, expression of the chemokine receptor
CXCR6, and up-regulation of Toll-like receptors (TLR) in
patients with implant-associated posttraumatic osteomyelitis
Implant-associated posttraumatic osteomyelitis is caused by bacterial biofilms, mostly
consisting of staphylococci species that colonize devices used for osteosynthesis, such
plates, nails, or screws, or prosthesis for joint replacement. In most cases, removal of
the infected implant is required. During surgery, cells having infiltrated the infected site
can be collected for phenotypical and functional characterization. Predominantly highly
activated polymorphonuclear neutrophils (PMN) were found as well as T lymphocytes,
the latter amounting to approximately 20 % of infiltrated cells. The majority of the
infiltrated T cells expressed CXCR6, a homing receptor for non-lymphoid tissue, while
CXCR6 expression on peripheral T cells was well below 20 %.
The infiltrated T cells, particularly the CD8+CD28-, produced 4gamma IFN, while the
peripheral blood T cells obtained from the same patient did not. Moreover, again
predominantly on the infiltrated T-cells Toll-like receptors were expressed. TLR1, TLR2
or TLR4 were found on small, but conspicuous T-cell populations that also expressed
CD11b+. The data lead to the following conclusion: persistent, localised bacterial
infections lead to the activation of T cells, and their infiltration into the infected site. It
is feasible that by producing 4gamma IFN the T cells enhance the efficiency of the local
effector cells, particularly of the PMN, and thereby support the local host defence.