Indirectly primed CD8+ T cells are a prominent component of the allogeneic T-cell repertoire after skin graft rejection in mice.
BACKGROUND
Alloreactive CD4 and CD8 T lymphocytes recognize antigen through both the direct and the indirect pathways. Although indirect priming of CD4+ T cells has been well described, little is known about the frequency and cytokine profile of indirectly primed CD8+ T cells during fully allogeneic graft rejection.


METHODS
We used a cytokine enzyme-linked immunosorbent spot assay to characterize indirect priming of alloreactive CD8 and CD4 cells in mice.


RESULTS
Interferon-gamma-producing CD8+ T cells specific for indirectly presented alloantigen were detectable in allograft-primed mice at a frequency of 50-100 per million cells (compared with 3000 per million for responses through the direct pathway) and were similar in frequency to indirectly primed CD4 cells.


CONCLUSIONS
CD8+ T cells primed through the indirect pathway are a prominent component of the alloreactive T-cell repertoire induced after skin graft placement in mice, raising the possibility that these cells may play a significant role in the rejection process itself.
Valujskikh
A
A
Department of Medicine, Case Western Reserve University and the Louis Stokes Cleveland, Department of Veterans Affairs Medical Center, Ohio 44106, USA.
Hartig
C
C
Heeger
P S
PS
D000818:Animals; D016516:CD4-CD8 Ratio; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology*; D005260:Female; D006084:Graft Rejection / Q000473:pathology*; D007124:Immunoenzyme Techniques / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016038:Skin Transplantation / Q000276:immunology* / Q000473:pathology*