Tissue Quantitation And Expression Of Chicken APN And Its Potentiality As IBV Receptor Evaluation

APN may be used as cell receptor of many group 1 coronavirus, and its significance in corovirus infection was known. Not all the coronavirus in a group or a category use same receptor, coronavirus may use multiple strategy make it easier bind to cell receptor, accordingly interreaction with the target cell. As a coronavirus, IBV must use cell receptor to entry the host cell, IBV cell receptor must be a specificity protein in chicken tissues.APN may also be the cell receptor of IBV and its significance in IBV need to be researched. These research needs to solve thus problems, is there correlation between enzyme activity and IBV tissue tropism? Is there regularity of nature distribution of chicken APN between IBV tissue tropism? Whether the chicken APN can help the heterogametic cell infected by IBV?In order to solve thus problems, the methods and results are as follows:To make clear the connection between IBV tissue tropism and enzymatic activity of chicken APN, this research determinate the absorptance changed before or after the reaction in 410nm of the same total protein reaction with idio substrates leu-pna after 30 minutes, which means the enzymatic activity changed of different tissue protein. The conclusion is there is a certain correlation between IBV tissue tropism and enzymatic activity of chicken APN, but the regularity isn't rigid;In order to make clear the correlation between mRNA express which represent the nature distribution of chicken APN and IBV cell tropism, real-time RT- PCR mehod was employed in this research, the conclusion indicated that there positive correlation between the APN distribution and cell tropism, the chickling expressed more APN then the adult, the kidney, respiratory tract and lung express stabilized in different stage, which can easily erosive by IBV, and APN expressed highly in intestinal tract at the later stage which display the APN anaphase expression correlation with the IBV advanced stage infection. All these coincidence the fact of APN may use as a helper constituents of IBV infection.Total length of APN gene was cloned from chick embryo in this research, after this, recombinant vector of prokaryotic expression was construction succeed, chicken APN was highly expressed in vitro, the prokaryotic expression protein was in inclusion body;For the purpose of exploring the function of APN in IBV infection, a eukaryotic expression vector carried with green fluorescence protein gene was construced succeed in this research, and its highly expressed in BHK-21, after the transfection, the BHK-21 become easily infected by IBV, the virus multiplied propagated, and the pathological changes decurtation along with the generation increased, and typical pathological changes appearance, which means IBV may use APN as the functional receptor of IBV.