Interleukin-12 inhibits murine graft-versus-host disease

Interleukin-12 (IL-12) is a potent immunostimulatory cytokine and an inducer of type-1 T-helper cell activity and of cytotoxic T lymphocyte and natural killer cell function. We report here the paradoxical observation that a single injection of 4,900 IU of recombinant murine IL-12 inhibits acute graft-versus-host disease (GVHD) in a fully major histocompatibility complex (MHC) plus multiple minor antigen-mismatched bone marrow transplantation (BMT) model (A/J-->B10). The protective effect was enhanced by administration of T-cell-depleted host-type BM cells, and complete donor-type lymphohematopoietic reconstitution was observed in most animals. Treatment with a protective course of IL-12 led to increased serum interferon-gamma (IFN-gamma) levels as compared with those for GVHD controls at early time points, when IFN-gamma was produced predominantly by host-type natural killer cells, but led to almost complete inhibition of the later GVHD-associated increase in serum IFN-gamma levels, when IFN-gamma is produced predominantly by CD4+ T cells. Furthermore, IL-12 treatment was associated with marked alterations in the kinetics of donor T-cell expansion. Reductions in donor CD4+ and CD8+ T cells were observed in the spleen on day 4 post- BMT, but a marked increase in donor CD8+ cells was observed on day 7. Unlike broadly immunosuppressive methods for inhibiting GVHD, which are associated with loss of antileukemic effects, IL-12 has the potential to mediate antileukemic effects of its own; therefore, the GVHD- inhibitory effects of IL-12 described here suggest a potential application for this cytokine in clinical BMT.     

大肠癌组织中表皮生长因子及受体的检测

本文应用免疫组化ABC法检测52例大肠癌和18例正常结肠组织中表皮生长因子（EGF）和表皮生长因子受体（EGF－R）的表达状况。正常组织中EGF阳性率22．2％，EGF－R阳性率16．7％，大肠癌EGF阳性率67．3％，EGF－R阳性率61．5％，二者均明显高于正常对照组织，（P＜0．05）。EGF和EGF－R阳性率与患者年龄，性别及肿瘤部位无明显相关，但随着肿瘤浸润度的加深，EGF与EGF－R的阳性率逐渐增高，有淋巴结转移者二者阳性率高于淋转阴性者，特别是EGF与EGF－R双阳者中有82．6％为进展期大肠癌，另发现低分化大肠癌中EGF和EGF－R阳性率明显低于中高分化癌。本文结果提示：部分大肠癌存在EGF或EGF－R的过度表达；EGF与EGF－R的过度表达与肿瘤润度及淋巴转移有关，其检测可作为诊断肿瘤恶性程度的一项辅助指标，部分正常大肠粘膜组织中也有少量EGF或EGF－R表达。