Abstract：Immunoglobulin A (IgA) Fc receptor (FcαR) can mediate the immune activation or immunosuppression of cells, which plays an important role in maintaining the homeostasis of immune response. The spleen of bactrian camel (Camelus bactrianus) is one of the main expression sites of FcαR, which can prompt corresponding immune response. In order to promote the research progress of bactrian camel immunology. In this study, the expression of FcαR positive cells in the red pulp, white pulp and marginal region of bactrian camel spleen was studied by preparing FcαR polyclonal antibody and using the spleen of young bactrian camel (1~2 years old), pubertal bactrian camel (3~5 years old) and adult bactrian camel (6~8 years old). The gene sequence of FcαR extracellular region in bactrian camel was firstly isolated and synthesized to construct the recombinant plasmid, which was transferred into Escherichia coli Rosetta for induction expression, and the induction conditions were optimized. The rabbit (Oryctolagus cuniculus) was next immunized with purified FcαR protein to produce a polyclonal antibody. After that, ELISA and Western blot were used to determine the titer and specificity of antibody serum. Finally, immunohistochemical staining and hematoxylin-eosin staining (HE) staining were used to analyze the distribution characteristics and the density of FcαR positive cells in different areas of spleen of bactrian camel in different age groups. The results showed the FcαR plasmid was expressed as inclusion bodies, and the optimal induction conditions were 0.7 mmol/L isopropyl β-D-thiogalactoside (IPTG) 5 h. The optimal elution concentration of hybrid protein was 5 mmol/L imidazole, and the antibody serum titer reached 1∶64 000, which could specifically recognize the recombinant protein FcαR. The distribution of FcαR positive cells was similar in the spleen of young, pubertal and adult bactrian camels, all of which were concentrated around the walls of sinuses and central arterial ducts in the red pulp region, and the positive cell type was dominated by monocytes/macrophages, with expression also observed on neutrophils and dendritic cells. In addition, the density of FcαR positive cells in the spleen of bactrian camels showed an obvious increasing trend from young to adult. The results suggested that the site of expression of FcαR positive cells in bimodal hump spleens was not affected by age, and that the increased number of positive cells in spleens with age provided some physiological basis for the refinement of their immune functions. This study provides reference for further exploring of immunological functions of bactrian camels.
李沛轩, 刘晓霞, 刘丽萍, 王雯慧. 双峰驼FcαR基因的原核表达、抗体制备及其在脾脏中的表达模式[J]. 农业生物技术学报, 2022, 30(10): 1944-1953.
LI Pei-Xuan, LIU Xiao-Xia, LIU Li-Ping, WANG Wen-Hui. Prokaryotic Expression, Antibody Preparation of FcαR Gene in Bactrian Camel (Camelus bactrianus) and Its Expression Pattern in Spleen. 农业生物技术学报, 2022, 30(10): 1944-1953.
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