title: The new immunosuppressant PLNPK prolongs allograft survival in mice.
abstract: The pentapeptide PLNPK (Pro-Leu-Asn-Pro-Lys) is extracted from the spleen. Preliminary studies have shown that PLNPK could inhibit T lymphocyte transformation and antibody production. In the present study, we detected the inhibitory effect of PLNPK on one-way mixed leukocyte reaction (MLR) in vitro and observed the effect of PLNPK on the duration of allograft survival in mouse models of skin or cardiac transplantation. Pathological damage and T cell infiltration of the grafts were also detected. Results showed that PLNPK could significantly inhibit T lymphocyte proliferation, with an optimized inhibition of 40%. Also PLNPK could significantly prolong the mean survival time of skin allograft and cardiac allograft, producing survival rates of 42% and 38.7%, respectively. PLNPK at a dose of 200 μg/kg/d or 100 μg/kg/d could significantly suppress ConA-induced T cell proliferation and T cell IL-2 secretion in transplant recipient mice, compared to the saline group (P<0.05). This information suggests that PLNPK can effectively antagonize transplant rejection, possibly by reducing IL-2 secretion by T cells and inhibiting T cell proliferation and activation.
authors.affiliation: Department of Immunology, Tianjin Medical University, Tianjin, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Lu
authors.forename: Junqiang
authors.initials: J
authors.lastname: Lv
authors.forename: Chunlei
authors.initials: C
authors.lastname: Zhou
authors.forename: Zheng
authors.initials: Z
authors.lastname: Fu
authors.forename: Qiong
authors.initials: Q
authors.lastname: Xu
authors.forename: Xuchun
authors.initials: X
authors.lastname: Che
authors.forename: Jing
authors.initials: J
authors.lastname: Jia
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.forename: Xueying
authors.initials: X
authors.lastname: Li
authors.forename: Gang
authors.initials: G
authors.lastname: Lin
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yao
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D006084:Graft Rejection / Q000188:drug therapy* / Q000276:immunology; D016027:Heart Transplantation; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009842:Oligopeptides / Q000008:administration & dosage*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D014184:Transplantation, Homologous
chemical_list: D007376:Interleukin-2; D009842:Oligopeptides; C533255:prolyl-leucyl-asparagyl-prolyl-lysine