Jp. Smith et al., USE OF ALLOGENEIC BONE-MARROW LABELED WITH NEOMYCIN RESISTANCE GENE TO EXAMINE BONE-MARROW-DERIVED CHIMERISM IN EXPERIMENTAL ORGAN-TRANSPLANTATION, Cell transplantation, 6(4), 1997, pp. 369-376
Posttransplant infusion of viable donor bone marrow cells (DBMC) has b
een shown in our previous studies to promote acceptance of incompatibl
e kidney allografts in rhesus monkeys after treatment with polyclonal
antithymocyte globulin to deplete peripheral T-lymphocytes, In this no
nhuman primate model, the infusion of the DBMC is requisite for the in
duction of functional graft tolerance and specific MLR and CTLp unresp
onsiveness, although the relevant role and fate of bone marrow-derived
chimeric cells is uncertain, Standard immunological and molecular tec
hniques applied to this monkey model are unable to differentiate betwe
en chimeric cells derived from the infused DBMC and those derived from
allograft-borne passenger leukocyte emigrants, To distinguish chimeri
sm due to infused DBMC, we transduced DBMC with a functional neomycin
resistance gene (Neo(r) using the retroviral vector pHSG-Neo. Neo(r)-t
ransduced BMC were infused into recipients approximately 2 wk after ki
dney transplantation and treatment with rabbit antithymocyte globulin,
No maintenance immunosuppressive drugs were given, Genomic DNA isolat
ed from peripheral blood leukocytes was used to monitor the presence o
f Neo(r)-positive cells. Tissue samples obtained at necropsy also were
assessed for Neo(r)-positive chimeric cells, The presence of DBMC-der
ived chimerism was assessed by polymerase chain reaction using Neo(r)
sequence-specific primers (PCR-SSP), Chimerism was detectable in recip
ient tissues at various times for up to 6 mo after DBMC infusion, Thes
e studies using gene transduction methodology indicate that a stable g
enetic marker can provide capability to examine DBMC-derived chimerism
for prolonged periods in a nonhuman primate model, This approach shou
ld facilitate future studies in preclinical models to study the role a
nd type of chimeric cell lineages in relation to functional allograft
tolerance. (C) 1997 Elsevier Science Inc.