【目的】 中华蜜蜂Apis cerana cerana（简称中蜂），其胞内胆固醇转运体AcNPC2a能够识别并结合几种微生物的细胞壁，AcNPC2存在于该蜂触角，参与嗅觉通讯，关于AcNPC2b的功能尚未见报道。【方法】 通过对中华蜜蜂AcNPC2b基因进行原核表达，以纯化的重组蛋白免疫小鼠，制备多克隆抗血清；利用荧光定量PCR和免疫印迹检测AcNPC2b的转录活性及蛋白水平，通过微生物结合测定对AcNPC2b的功能进行探索。【结果】 中蜂AcNPC2b含有信号肽和ML结构域，具有3个二硫键，与果蝇Drosophila melanogaster DmNPC2b聚为一个亚枝。荧光定量qRT-PCR检测发现，感染中蜂囊状幼虫病毒（Chinses sacbrood virus，简称CSBV）的幼虫体内AcNPC2b基因的表达呈现出先微弱下调再持续上调的趋势。获得了约16 ku的重组蛋白AcNPC2b并制备了多克隆抗体，免疫印迹结果表明，中蜂AcNPC2b蛋白在工蜂头、胸与中肠中的表达量最高，触角、马氏管与脂肪体中次之。AcNPC2b蛋白在正常与感染CSBV病毒的中蜂幼虫中均有表达，且在感染CSBV的中蜂幼虫中有微弱上调。重组蛋白AcNPC2b微生物结合测定实验结果显示中蜂AcNPC2b重组蛋白均能与活的大肠杆菌、金黄色葡萄球菌、芽孢杆菌以及白僵菌结合。【结论】 正常与感染CSBV病毒的中蜂幼虫体内AcNPC2b基因转录水平和AcNPC2b蛋白的表达含量存在差异，重组蛋白AcNPC2b具有识别并结合病原菌的能力，为后续深入研究AcNPC2b蛋白的分子功能奠定了一定理论基础。

[Objectives]  To investigate the expression of the Apis cerana Niemann-Pick disease type C2b (AcNPC2b) gene, an intracellular cholesterol transporter that can recognize and bind to the cell walls of several microorganisms. [Methods]  The AcNPC2b gene was expressed in a prokaryotic bacteria and the purified recombinant protein obtained used to immunize mice to prepare polyclonal antiserum. The transcriptional and translational activity of AcNPC2b in various tissues were then detected by fluorescent quantitative PCR and western blotting, respectively. Finally, the function of AcNPC2b was investigated using a microbial binding assay. [Results]  AcNPC2b contains signal peptide and ML domains with 3 disulfide bonds. A phylogenetic tree shows that AcNPC2b and the DmNPC2b gene of Drosophila melanogaster cluster on the same sub-branch. qRT-PCR indicates that AcNPC2b gene expression is generally weakly down-regulated, then continuously up-regulated, in CSBV-infected larvae. A recombinant protein of about 16 ku was obtained. Western blotting results indicate that the AcNPC2b protein is most highly expressed in the head, thorax and midgut, followed by the antennae, Malpighian tubules and fat body. Immunoblotting indicates that the AcNPC2b protein was slightly up-regulated in CSBV-infected larvae compared to healthy larvae. The microbial binding assay showed that the recombinant protein rAcNPC2b protein binds directly to Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Beauveria bassiana, which suggests that it plays a role in pathogen recognition and the immune response. [Conclusion]  There were differences in both the transcription and translation of AcNPC2b between healthy and CSBV infected larvae. A recombinant AcNPC2b protein was able to recognize and bind to pathogenic bacteria. These results provide a theoretical foundation for subsequent in-depth study of the molecular function of the AcNPC2b protein.