Elevated numbers of Fc gamma RIIIA+ (CD16+) effector CD8 T cells with NK cell-like function in chronic hepatitis C virus infection.
CTL are crucial in the defense against viral infections. In the course of investigating peripheral blood and intrahepatic CD8 T cells in patients with chronic hepatitis C virus (HCV) infection, we observed a significant population of CD8 T cells expressing the FcgammaRIIIA (CD16) receptor. This observation led us to characterize these cells with respect to their phenotype and function in a cohort of patients with chronic HCV infection as well as in healthy blood donors. On average, 10% of peripheral blood CD8 T cells from HCV-infected patients expressed CD16 compared with only a few percent in healthy donors. CD16(+) CD8 T cells displayed a late-stage effector phenotype with high levels of perforin. These cells exhibited a restricted TCR profile suggesting underlying clonal expansion. Stimulation of CD16 on CD8 T cells evoked a vigorous response similar to that of CD16 stimulation in NK cells. Our data suggest that CD8 T cells, during chronic HCV infection in humans, continue to differentiate beyond defined stages of terminal effector cells, acquiring CD16 and NK cell-like functional properties.
Björkström
Niklas K
NK
Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden. Niklas.bjorkstrom@ki.se
Gonzalez
Veronica D
VD
Malmberg
Karl-Johan
KJ
Falconer
Karolin
K
Alaeus
Annette
A
Nowak
Greg
G
Jorns
Carl
C
Ericzon
Bo-Göran
BG
Weiland
Ola
O
Sandberg
Johan K
JK
Ljunggren
Hans-Gustaf
HG