A new generation of rabbit anti-human leukocyte polyclonal antibody in inhibiting xenogeneic cell-mediated immune pesponses
10.3760/cma.j.issn.0254-1785.2009.02.012
- VernacularTitle:新一代多克隆抗体抑制异种细胞免疫反应的研究
- Author:
Liangming ZHU
;
Yusong FANG
;
Zidong LIU
;
Xi WANG
;
Xiuqing GUO
;
Yunshan WANG
;
Ke XU
- Publication Type:Journal Article
- Keywords:
Antibodies;
Endothelial cells;
Monocytes
- From:
Chinese Journal of Organ Transplantation
2009;30(2):103-106
- CountryChina
- Language:Chinese
-
Abstract:
Objective Delayed xenograft rejection (DXR) is a major barrier to the long-term xenograft survial.This study evaluated the interaction between human peripheral blood mononuelear cells (PBMC) and porcine endothelial cells (PEC),and the effects of new generation of rabbit antihuman leukocyte polyclonal antibody (newRALG) inhibiting xenogeneic cell-mediated immune responses.Methods newRALG was obtained from rabbits after immunization with activated lymphocytes and monoeytes.PEC were isolated from aorta,and human PBMC were isolated from peripheral blood.Co-cultures of PKH-26 labeled PEC with PBMC were established,newRALG,thymoglobulin,isotype Ig and scavenger receptor (SR) ligand poly G were added into the co-cultures.Cells were collected,then FACS analysis was carried out to detect the up-take of PEC membrane by monocytes and the expression of costimulatory molecules.Lymphocyte proliferative responses to PEC with or without antibody were evaluated by a xenogeneie mixed lymphocyte-endothelial cell reaction (xMLER).Results FACS analysis revealed that monocytes from PBMC-PEC co-cultures became positive for PKH-26 following their interaction with PKH-26 labeled PEC,indicating that they engulfed PEC membranes during activation.PKH-26 positive monocytes up-regulated the CD40 and CD80 expression.Furthermore,SR blockade with poly-G prevented PEC membrane up-take by monocytes,newRALG greatly reduced SR-mediated PEC membrane up-take.The effects of thymoglobulin in inhibiting PEC membrane uptake were limited.xMLER demonstrated strong lymphocyte proliferation in response to PEC,and lymphocyte proliferation was dramatically inhibited by newRALG but not isotype Ig at a dosmdependent manner.Conclusions Monocytes play an important role in xenogeneic immune responses.SR ligand poly G inhibits PEC membrane up-take.newRALG inhibits PEC membrane up-take by monocytes,suggesting that newRALG blocks SR.Additionally,newRALG inhibits lymphocyte proliferation in response to PEC.These results suggest that this new polyclonal preparation may thus impair the initiation of xeno-specific immune responses and prevent xenograft rejection.
