V. Gelfanova et al., Characterization of Haemophilus ducreyi-specific T-cell lines from lesionsof experimentally infected human subjects, INFEC IMMUN, 69(7), 2001, pp. 4224-4231
Haemophilus ducreyi is the etiologic agent of chancroid, a sexually transmi
tted genital ulcer disease that facilitates the transmission of human immun
odeficiency virus. In the human model of infection, the histopathology of i
nfected sites in part resembles a delayed-type hypersensitivity (DTH) respo
nse. In this study, T cells were isolated from skin biopsy specimens obtain
ed from 24 subjects who were infected for 7 to 14 days. One clone and 12 li
nes that responded to H. ducreyi antigens were obtained from 12 of the subj
ects. Fluorescence-activated cell sorter analysis showed that the antigen-r
esponsive lines and clone were predominantly CD3(+) and CD4(+), The lines a
nd clone responded to H. ducreyi antigen in a dose-dependent manner and pro
duced gamma interferon (IFN-gamma) alone or IFN-gamma and interleukin-10 (I
L-10) but no IL-4 or IL-5 in response to H. ducreyi, Proliferation of T cel
ls was dependent on the presence of autologous antigen-presenting cells. Th
e lines showed little response to antigens prepared from other members of t
he Pasteurellaceae and responded to different fractions of H, ducreyi separ
ated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophores
is. We conclude that T cells that recognize H, ducreyi antigens are recruit
ed to sites experimentally infected with the organism. The lack of cross-re
activity to the Pasteurellaceae and the response of the lines to different
antigen fractions suggest that subjects are sensitized to H. ducreyi during
the course of infection.