Pathogenic microorganisms can cause a variety of infectious diseases. Large - scale outbreaks of infectious diseases such as Ebola hemorrhagic fever, COVID - 19 infection, and malaria pose severe threats to human life and health, and even trigger social crises. This has driven researchers to seek simpler and more effective methods for treating infectious diseases. Controlling the source of infection, cutting off the route of transmission, and protecting susceptible populations are the keys to preventing and controlling infectious diseases.

Since their discovery, nanobodies have been widely applied in fields such as tumor/neurological disease research and imaging diagnosis. In recent years, researchers have gradually expanded their application to more domains, including food safety and environmental hygiene testing. Recently, researchers have conducted studies on the application of nanobodies in animal husbandry.

Chemokines are a class of small cytokines or signaling proteins secreted by cells. They are so named because of their ability to induce directional chemotaxis of nearby responsive cells. All their receptors belong to the G protein - coupled receptor (GPCR) family with 7 - transmembrane domains, and are mainly expressed in cells such as neutrophils, macrophages, epithelial cells, smooth muscle cells, and fibroblasts ^[1].

In the 1970s, scientists discovered the first incretin hormone, GIP (Glucose-Dependent Insulinotropic Polypeptide), and later identified the second incretin hormone: Glucagon-Like Peptide-1 (GLP-1). GLP-1 is secreted by intestinal L cells in the distal small intestine and proximal colon, encoded by the proglucagon gene, and is a polypeptide consisting of 30 amino acids^[1-3].