Xu Kailin, Li Chaohong, Pan Xiuying, Du Bing
Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, Jiangsu, PR China.
Int J Hematol. 2007 Jul;86(1):84-90. doi: 10.1532/IJH97.A10613.
Engagement of the TCR without appropriate costimulation will result in the inability of T-cells to respond to the alloantigen as described earlier. We made a further investigation into the effect of relieving graft-versus-host disease (GVHD) and its mechanism in mice by blocking CD137-CD137L pathway in vitro. Responder cells (spleen cells) from BALB/C donor mice (H-2d) were incubated with stimulator cells (spleen cells) from C57BL/6 recipient mice (H-2b), with or without anti-CD137L monoclonal antibodies (MoAbs). Donor bone marrow cells plus mixed lymphocyte culture (MLC) T-cells were transplanted into lethally irradiated C57BL/6 mice. C57BL/6 mice were divided into 3 groups: group A (allogeneic bone marrow transplantation control group), group B (cyclosporine + methotrexate group), and group C (donor T-cells were treated with anti-CD137L MoAbs). The percentage of CD3+CD4+ and CD3+CD8+ T-cells were detected by flow cytometry, and the levels of cytokines (IFN-gamma, interleukin [IL]-2, IL-10, IL-4) by reverse-transcriptase polymerase chain reaction. The incidence of GVHD in group C was 70%, while the incidence of GVHD was 100% in group A and group B. The survival rate of group C was higher than that of group A and B, and the median survival time was longer than that of group A and B (P < .01). Clinical symptoms and histological signs of GVHD in group C were the mildest among all 3 groups. The percentage of CD3+CD8+T-cells in group C was lower than that in group A and B (P < .01). The levels of IFN-gamma in group C were markedly lower than those in group A and B (P < .01), and the levels of IL-10 in group C were significantly higher than those in group A and B (P < .01). The results suggest that treatment of donor T-cells by anti-CD137L MoAbs in vitro may relieve GVHD, thereby improve the survival time and survival rate of recipient mice, which might be related to the increased TH1 cytokine (IFN-gamma) and decreased TH2 cytokine (IL-10) as well as the reduced CD3+CD8+T-cells.
如前所述，在没有适当共刺激的情况下，T细胞受体的激活将导致T细胞无法对同种异体抗原作出反应。我们进一步研究了在体外阻断CD137 - CD137L通路对缓解小鼠移植物抗宿主病（GVHD）的作用及其机制。将来自BALB/C供体小鼠（H-2d）的反应细胞（脾细胞）与来自C57BL/6受体小鼠（H-2b）的刺激细胞（脾细胞）一起培养，同时加入或不加入抗CD137L单克隆抗体（MoAbs）。将供体骨髓细胞加混合淋巴细胞培养（MLC）的T细胞移植到经致死性照射的C57BL/6小鼠体内。将C57BL/6小鼠分为3组：A组（同种异体骨髓移植对照组）、B组（环孢素+甲氨蝶呤组）和C组（供体T细胞用抗CD137L MoAbs处理）。通过流式细胞术检测CD3 + CD4 +和CD3 + CD8 + T细胞的百分比，通过逆转录聚合酶链反应检测细胞因子（IFN-γ、白细胞介素[IL]-2、IL-10、IL-4）的水平。C组GVHD的发生率为70%，而A组和B组GVHD的发生率为100%。C组的存活率高于A组和B组，中位生存时间长于A组和B组（P < 0.01）。C组GVHD的临床症状和组织学体征在所有3组中最为轻微。C组中CD3 + CD8 + T细胞的百分比低于A组和B组（P < 0.01）。C组中IFN-γ的水平明显低于A组和B组（P < 0.01），C组中IL-10的水平明显高于A组和B组（P < 0.01）。结果表明，体外使用抗CD137L MoAbs处理供体T细胞可能缓解GVHD，从而提高受体小鼠的生存时间和存活率，这可能与TH1细胞因子（IFN-γ）增加、TH2细胞因子（IL-10）减少以及CD3 + CD8 + T细胞减少有关。
