Composite tissue allotransplantation in chimeric hosts: part I. Prevention of graft-versus-host disease.
BACKGROUND
Mixed allogeneic chimerism (MAC) has been shown to induce tolerance to composite tissue allografts (CTA). However, transplantation of unmanipulated donor-specific limbs results in severe graft-versus-host disease (GVHD). This suggests that nontolerant mature donor-derived cells in the CTA may affect the stability of chimerism, potentially resulting in GVHD. The aim of this study was to develop an approach to study and prevent GVHD in a mixed chimeric-rat hind-limb transplantation model.


METHODS
[ACI-->WF] chimeras received a limb from Wistar Furth (WF) (syngeneic), Fisher (third-party), or ACI (irradiated [1,050 cGy] or nonirradiated) rats. In vitro tolerance was assessed using mixed lymphocyte reactivity (MLR) assays at the time the animals were killed.


RESULTS
[ACI-->WF] chimeras with greater than 85% chimerism exhibited rejection-free survival of donor-specific hind limbs. However, 100% of these animals developed lethal GVHD 22.4+/-2.8 days after limb transplantation. [ACI-->WF] chimeras that underwent transplantation with irradiated ACI or syngeneic WF limbs showed no signs of rejection or GVHD at 5 months. Nonchimeric and third-party controls rejected limbs within 10 days.


CONCLUSIONS
Conditioning of the host WF rats with 950 cGy of irradiation (sublethal, myeloablative) led to high levels of MAC without GVHD. The mature T-cell content of nonirradiated donor (ACI) limbs was sufficient to induce lethal GVHD in 100% of tolerant mixed chimeric [ACI-->WF] hosts. Irradiation of donor limbs before transplantation resulted in long-term donor-specific tolerance and prevented GVHD. These data demonstrate that (1) established chimeras could be susceptible to GVHD caused by immunocompetent donor cells transferred with the hind limb, and (2) inactivating these cells with irradiation prevents GVHD and destabilization of chimerism, and permits rejection-free graft acceptance.
Gorantla
Vijay S
VS
Division of Plastic and Reconstructive Surgery, Plastic Surgery Research, University of Louisville, 511 South Floyd Street, Louisville, KY 40292, USA.
Prabhune
Kaustubha A
KA
Perez-Abadia
Gustavo
G
Ildstad
Suzanne T
ST
Maldonado
Claudio
C
Orhun
Haldun I
HI
Majzoub
Ramsey K
RK
Francois
Cedric G
CG
Kakoulidis
Thanos P
TP
Brouha
Pascal C R
PC
Anderson
Gary L
GL
Pidwell
Diane J
DJ
Breidenbach
Warren C
WC
Barker
John H
JH
D000818:Animals; D002460:Cell Line; D006085:Graft Survival; D006086:Graft vs Host Disease / Q000517:prevention & control*; D006614:Hindlimb / Q000528:radiation effects / Q000637:transplantation*; D008297:Male; D051381:Rats; D011912:Rats, Inbred ACI; D011916:Rats, Inbred F344; D011920:Rats, Inbred WF; D014019:Tissue Donors; D018183:Transplantation Chimera; D023001:Transplantation Tolerance; D014184:Transplantation, Homologous