Antiproliferative effects of NKH477, a forskolin derivative, on cytokine profile in rat lung allografts.
OBJECTIVE
NKH477 was recently identified as a water-soluble forskolin derivative and was reported to prolong survival of murine cardiac allografts. However, the mechanism of the efficacy is not clear in vivo. The aim of this study was to investigate the immunosuppressive effects of NKH477 on acute lung allograft rejection in the rat model and its mechanism of action in vivo.


METHODS
Left lungs were transplanted orthotopically from Brown-Norway donors to Lewis recipients. Recipient rats were untreated or treated daily with different doses of NKH477. Grafts were excised on Day 3 or Day 5 to determine histopathological rejection and expressions of interleukin (IL)-2, IL-4, IL-10, and interferon (IFN)-gamma by enzyme-linked immunosorbent assay. The cytokine expression at Day 3 or Day 5 was also evaluated in recipient spleens by immunohistochemistry. Furthermore, mesenteric lymph node cells from recipients at Day 5 were cultured alone or stimulated with donor antigens for 72 hours to determine cell proliferation by means of thymidine incorporation.


RESULTS
NKH477 significantly extended allograft survival time in a dose-dependent manner and reduced histopathological rejection. Treatment with NKH477 inhibited IFN-gamma and IL-10 expression, whereas expression of these cytokines were markedly upregulated in the untreated allografts. Expression of IL-2 and IL-10 also increased in the spleen of untreated allorecipients. NKH477 suppressed expression of both cytokines in the spleen. In addition, lymphocyte proliferation was inhibited in NKH477-treated recipients as compared with untreated recipients.


CONCLUSIONS
These results suggest that NKH477 exerts an antiproliferative effect on lymphocytes in vivo with an altered cytokine profile in rat recipients of lung allografts.
Nakashima
Shinji
S
Department of Thoracic and Cardiovascular Surgery, Sapporo, Japan.
Morikawa
Masayuki
M
Komatsu
Kanshi
K
Matsuura
Akihiro
A
Sato
Noriyuki
N
Abe
Tomio
T
D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D005576:Colforsin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D016207:Cytokines / Q000378:metabolism*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D006084:Graft Rejection / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006085:Graft Survival / Q000187:drug effects / Q000276:immunology; D007150:Immunohistochemistry; D008168:Lung / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D016040:Lung Transplantation / Q000276:immunology / Q000473:pathology*; D008198:Lymph Nodes / Q000187:drug effects / Q000473:pathology; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D013154:Spleen / Q000378:metabolism; D014184:Transplantation, Homologous
D000276:Adjuvants, Immunologic; D016207:Cytokines; D005576:Colforsin