Kinetic analysis of microchimerism induced by intrathymic injection of allogeneic splenocytes in mice.
Allograft survival facilitated by intrathymic (i.t.) injection of allogeneic cells have shown that modifications of T-cell development induce specific tolerance. One hypothesis is that the resulting microchimerism may play a role in preparing the host immune system for the allograft. To investigate whether the deliberate introduction of allogeneic splenocytes into the thymus of adult mice allows the establishment of a lasting donor/recipient microchimerism, a full allogeneic mouse system (H-2 and Mls) with additional sex mismatch was used. Male cells injected into female mice were detected using an optimized nested-polymerase chain reaction which specifically amplifies the SRY gene with a sensitivity of 1/10(4). After i.t. injection, donor cells were observed early both in the lymph nodes and spleen (75 and 25% of mice, respectively). They were still present on day 6, although preferentially in the thymus (100% of mice) than in the lymph nodes (50% of mice) or in the spleen (22% of mice). After intraperitoneal (i.p.) or subcutaneous (s.c.) injection, donor cells were early (2 h) but transiently detected in the thymus, since on day 6 they were detected in 0 and 17% of mice after i.p. and s.c. injection, respectively. Kinetics of donor-cell detection was similar both in the spleen and lymph nodes with a clear decrease in the percentage of mice with donor-cell detection between day 2 and day 6 (20 and 17% of positive mice for the spleen after i.p. and s.c. injections, respectively--20 and 33% of positive mice for the lymph nodes after i.p. and s.c. injections, respectively). Our results clearly show that i.t. injection of allogeneic splenocytes induces a microchimerism which is both more lasting and detected in a higher percentage of mice than by the i.p. and s.c. routes, both at the central (thymus) and peripheral (spleen) levels.
Guerra
N
N
Laboratory of Thymic Physiology, CNRS-ESA 8078, I.P.S.C., Faculté de Médecine Paris-XI, Hôpital Marie-Lannelongue, Le Plessis-Robinson, France.
Goettelfinger
P
P
Lecerf
F
F
Berrih-Aknin
S
S
German-Fattal
M
M
D000818:Animals; D002465:Cell Movement; D017690:Cell Transplantation; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D007267:Injections; D007274:Injections, Intraperitoneal; D007279:Injections, Subcutaneous; D007700:Kinetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009687:Nuclear Proteins; D051876:Sex-Determining Region Y Protein; D013154:Spleen / Q000166:cytology / Q000502:physiology*; D013950:Thymus Gland / Q000166:cytology / Q000502:physiology*; D014157:Transcription Factors; D018183:Transplantation Chimera / Q000502:physiology*
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D051876:Sex-Determining Region Y Protein; C497746:Sry protein, mouse; D014157:Transcription Factors