DISTINCT HUMAN MACROPHAGE RECEPTOR FOR ABNORMAL VLDL

血浆甘油三酯（TG）升高是动脉粥样硬化血栓形成的危险因素 疾病单核细胞-巨噬细胞（MM）衍生的充满脂质的“泡沫细胞”是 在动脉粥样硬化病变中发现，在某些高TG状态下，在骨中发现 骨髓皮肤和脾脏富含TG的脂蛋白（TGRLP）的摄取 细胞表面，apoE非依赖性TGRLP受体（R），与以前不同 描述了我们在人类MM中鉴定的Rs可能参与泡沫细胞 人类的形成。来自纯化的人THP-1 R的独特序列数据 允许产生R特异性的抗肽抗体， 天然的200和235 kDa R形式，并证明这种R是独特的。的目标 本文拟做的工作是：（1）完成分子和功能的研究， 表征这个新的和独特的R和（2），以确定R- 乳糜微粒和HTG-VLDL的apoB内的结合结构域以及 其他TGRLP组分对R结合的影响。分子生物学 方法将识别和测序受体互补DNA克隆， 阐明受体一级结构，表征细胞mRNA，和 识别、定位和表征基因组DNA， 潜在的调节、组织特异性元素和潜在的关系 致动脉粥样硬化的小而密的LDL表型。35 kDa的R亚基将 通过免疫亲和纯化从235 kDa形式中分离 235 kDa形式的R，然后进行抗体的制备型SDS-PAGE 生产和微序列分析。R合成，细胞路线， 亚基相互作用和组织分布将进行评估， 特异性R抗血清。竞争性和直接的细胞结合和配体 用天然和修饰的VLDL、模型VLDL和映射的VLDL进行印迹研究， 针对apoB的单克隆抗体将精确定位R结合决定簇。 这些研究应该提供基本的细胞和分子机制 与人体泡沫细胞形成有关。

Elevated plasma triglycerides(TG) are a risk factor for atherothrombotic disease. Monocyte-macrophage(MM)-derived, lipid-filled "foam cells" are found in atherosclerotic lesions and, in certain hyperTG states, in bone marrow, skin, and spleen. Uptake of TG-rich lipoproteins(TGRLP) via a cell-surface, apoE-independent TGRLP receptor(R) distinct from previously described Rs that we identified in human MM may be involved in foam cell formation in humans. Unique sequence data from the purified human THP-1 R allowed production of R-specific, antipeptide antibodies that bind the native 200 and 235 kDa R forms and prove this R is unique. The goals of the proposed work are (1)to complete the molecular and functional characterization of this new and unique R and (2) to identify the R- binding domain(s) within the apoB of chylomicrons and HTG-VLDL and the effects of other TGRLP components on R binding. Molecular biological approaches will identify and sequence receptor complementary DNA clones to elucidate receptor primary structure, to characterize cellular mRNA, and to identify, localize, and characterize the genomic DNA to identify potential regulatory, tissue-specific elements and potential relationship to the atherogenic, small, dense LDL phenotype. The 35kDa R subunit will be isolated from the 235 kDa form by immunoaffinity purification of the 235 kDa form of the R followed by preparative SDS-PAGE for antibody production and microsequence analysis. R synthesis, cell itinerary, subunit interactions, and tissue distribution will be assessed with specific R antisera. Competitive and direct cell binding and ligand blotting studies with native and modified VLDL, model VLDL, and mapped monoclonal antibodies against apoB will pinpoint R binding determinants. These studies should provide basic cellular and molecular mechanisms pertinent to foam cell formation in humans.