Y. Zhao et al., FUNCTIONALLY AND PHENOTYPICALLY MATURE MOUSE CD8(-CELLS DEVELOP IN PORCINE THYMUS GRAFTS IN MICE() T), Xenotransplantation, 5(1), 1998, pp. 99-104
Citations number
28
Categorie Soggetti
Transplantation,"Medicine, Research & Experimental
Mouse CD4(+) T cells efficiently develop in fetal pig thymus (FP THY)
grafts and repopulate the periphery of T cell and NK cell-depleted, th
ymectomized (ATX) mice. However, efficient peripheral repopulation of
mouse CD8(+) T cells does not occur in these mice. We have therefore e
valuated the maturation and function of mouse CD8 single positive (SP)
thymocytes in fetal pig thymus and liver fragment (FP THY LIV) grafts
. Phenotypic maturity, as measured by upregulated expression of TCR, c
lass I MHC, and Qa-2, and downregulated expression of heat stable anti
gen (HSA) on CD8 SP cells in FP THY grafts, was similar to that in hos
t thymi of euthymic control mice. Cytolytic T lymphocyte (CTL) activit
y of thymocytes from FP THY grafts was similar to that of thymocytes f
rom host thymi of euthymic mice, indicating that functional maturation
of CD8 SP cells had taken place in the grafts. Furthermore, similarly
efficient deletion of V beta 5.1/5.2(+) and V beta 11(+) CD8 SP cells
was observed in FP THY grafts as in host thymi of euthymic control mi
ce. Similar percentages of V beta 6, V beta 7, and V beta 8.1/8.2 expr
essing cells were also detected among CD8 SP cells in FP THY grafts an
d host thymi of euthymic controls. Together, our results suggest that
normal positive and negative selection occurs, and that mouse CD8(+) c
ells can undergo normal functional and phenotypic maturation in FP THY
grafts. Thus, other explanations must be sought for the failure of CD
8(+) cells to repopulate the peripheral lymphoid tissues of ATX, T cel
l-depleted, pig THY/LIV-grafted mice.