Nanobodies are derived from the variable domain of the heavy-chain antibodies (HCAbs) that occur naturally in the serum of Camelidae. They are the smallest antibody fragments capable to bind antigens. With the characteristics of their increased solubility, increased domain stabilities, nanomolar affinities, easy crossing the blood-brain barrier, easy generation, engineering, optimization and tailoring, easy humanization, nanobodies have extensive application prospects in diagnosis and detection. Although nanobody has demonstrated tremendous success, a number of practical challenges limit its broader applications in disease diagnosis and detection, including construction of a phage library and selection of nanobody fragments with high affinity and immunogold labeling technique. Here, we review several recent findings on the use of nanobodies in molecular diagnostics and suggest some practical strategies in resolving the current challenges in this attractive research area, particularly to optimize the affinity, solubility, humanization of nanobodies.
Humans ; Immunoglobulin Heavy Chains ; chemistry ; Single-Domain Antibodies ; chemistry ; drug effects

In recent years, the regulatory role of microRNAs in liver pathological process has attracted more and more attention. In viral hepatitis and steatohepatitis, microRNA-335 (miRNA-335) regulates the progression of hepatitis via the transcription factor sex-determining region Y-box 4; in the development and progression of progressive liver fibrosis and liver cancer, miRNA-335 affects collagen production, deposition, and degradation in the liver via the target genes including hypoxia-inducible factor 1α, phosphatase and tensin homologue, Rho-associated coiled-coil containing protein kinase 1, plasminogen activator inhibitor-1, twist family bHLH transcription factor 1, and mesenchymal-epithelial transition factor and thus regulates the migration and invasion of hepatic stellate cells and hepatoma cells. This article summarizes the research advances in the role of miRNA-335 in hepatitis, liver fibrosis, and liver cancer in recent years, and based on existing data, it is pointed out that the miRNA-335/QSOX1 regulatory axis may mediate artesunate against schistosomal liver fibrosis by inhibiting hepatic stellate cell activation, so as to provide new ideas for the treatment of liver fibrosis and other liver diseases.

Objective. This study characterized the activation of platelet integrin aⅡbβ3 induced by two anti-human platelet te-traspanin monoclonal antibodies(mAbs),HI117 and SJ9A4. Methods. Using 125I-labeled human fibdnogen(Fg), specific Fg binding to human platelets induced by HI117 and SJ9A4 was measured as indication of activation of platelet integrin αⅡbβ3 by the two mAbs. Results. H1117 and SJ9A4( 10μg/ml and 20μg/ml) induced evident specific Fg binding to human platelets, sug-gesting that the two mAbs evoked activation of platelet integrin αⅡbβ3. Further study indicated that HI117 and SJ9A4 induced integrin t Ⅱ 1β3 activation independent of platelet Fc-receptors, and that HI117 and SJ9A4-induced integrin αⅡbβ3 activation was inhibited by sphingosing, aspirin, apyrase, and/or PGI2. Conclusion. The anti-platelet tetraspanin(CD9)mAbe,HI117 and SJ9A4, can induce platelet integrin αⅡbβ3 act-vation independent of Fc-receptors. Three signaling pathways,i.e.thromboxane,secreted ADP, and cAMP pathways may be involved in the process, with protein kimse C activation presumably being the comtmon step of the three pathways.

Objectives　To characterize the activation of platelet integrin αⅡbβ3 induced by two anti-human platelet tetraspanin monoclonal antibodies (mAbs), HI117 and SJ9A4, and investigate their potential mechanism of action. Methods　Using 125　　I-labeled human fibrinogen (Fg), specific Fg binding to human platelets induced by HI117 and SJ9A4 was measured. Results　HI117 and SJ9A4 (10?μg/ml and 20?μg/ml) induced specific Fg binding to human platelets, suggesting that the two mAbs evoked activation of platelet integrin αⅡbβ3. Further study indicated that HI117 and SJ9A4 induced integrin αⅡbβ3 activation independent of platelet Fc-receptors, and that HI117 and SJ9A4-induced integrin αⅡbβ3 activation was inhibited by pretreatment of platelets with sphingosine, aspirin, apyrase, and/or PGI2. Conclusions　Anti-platelet tetraspanin (CD9) mAbs, HI117 and SJ9A4, can induce platelet integrin αⅡbβ3 activation independent of Fc-receptors. Three signaling pathways, namely thromboxane, secreted ADP, and cAMP pathways, may be involved in the process, with protein kinase C activation presumably being the common step of the three pathways.