Induction of indefinite survival of fully allogeneic cardiac grafts and generation of regulatory cells by intratracheal delivery of alloantigens under blockade of the CD40 pathway.
BACKGROUND
The authors previously showed that intratracheal delivery (ITD) of donor splenocytes induced prolonged survival of fully allogeneic cardiac grafts in mice. In this study, this treatment protocol was combined with blockade of the CD40 pathway in an attempt to induce operational tolerance.


METHODS
CBA mice were given donor splenocytes (1x107) or Kb peptide (100 microg) by ITD with or without antibody specific for mouse CD40 ligand (MR1, 200 microg) 7 days before transplantation of a C57BL/10 heart. Also, splenocyte (5 x 107) from primary recipient CBA mice given ITD of donor splenocytes or Kb peptide plus MR1 were adoptively transferred into naive CBA secondary recipients 7 days after the pretreatment and C57BL/10 hearts were transplanted into those recipients the same day.


RESULTS
ITD of donor splenocytes and Kb peptide induced prolonged survival of cardiac grafts (median survival time [MST], 74 and 56 days, respectively), whereas naive control mice and mice pretreated with syngeneic splenocytes had acute graft rejection (MST in both groups, 7 days). When MR1 was included, all grafts survived indefinitely (>200 days), but mice pretreated with MR1 alone had graft rejection (MST, 54 days). Mice bearing cardiac grafts had acceptance of skin grafts from C57BL/10 but not BALB/c mice, demonstrating that operational tolerance was induced. Secondary recipients given adoptive transfer of splenocytes from primary recipients of the combined treatment had acceptance of C57BL/10 grafts, suggesting that regulatory cells were generated within 7 days of pretreatment.


CONCLUSIONS
ITD of donor splenocytes or Kb peptide under blockade of the CD40 pathway induced operational tolerance and generated regulatory cells.
Uchida
Norio
N
Department of Surgery, Keio University, Tokyo, Japan.
Shirasugi
Nozomu
N
Akiyama
Yoshinobu
Y
Matsumoto
Kenji
K
Shimazu
Motohide
M
Kitajima
Masaki
M
Hamano
Kimikazu
K
Aramaki
Osamu
O
Ikeda
Yoshifumi
Y
Niimi
Masanori
M
D019264:Adoptive Transfer; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D019013:CD40 Antigens / Q000276:immunology; D023201:CD40 Ligand / Q000276:immunology*; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D006085:Graft Survival / Q000276:immunology*; D016027:Heart Transplantation / Q000276:immunology* / Q000401:mortality*; D007519:Isoantigens / Q000494:pharmacology*; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D016038:Skin Transplantation; D013154:Spleen / Q000166:cytology; D015996:Survival Rate; D014132:Trachea
D000911:Antibodies, Monoclonal; D019013:CD40 Antigens; D016207:Cytokines; D007519:Isoantigens; D023201:CD40 Ligand