This application is directed generally to foot-and-mouth disease virus (FMDV) 3C proteases that have been modified by mutating a polynucleotide sequence coding for the FMDV 3C protease. The modified FMDV proteases exhibit proteolytic activity on FMDV P1 precursor protein and exhibit a reduction in one or more toxic or inhibitory properties associated with an unmodified FMDV 3C protease on a host cell used to recombinantly produce it. Vectors carrying polynucleotides encoding modified FMDV 3C protease sequences can induce production of FMDV virus-like particles in a host cell when expressed in the host cell. The modified FMDV 3C proteases can generally be used to produce immunogenic FMDV preparations capable of inducing an immune response against FMDV.

This application is directed generally to foot-and-mouth disease virus (FMDV) 3C proteases that have been modified by mutating a polynucleotide sequence coding for the FMDV 3C protease. The modified FMDV proteases exhibit proteolytic activity on FMDV P1 precursor protein and exhibit a reduction in one or more toxic or inhibitory properties associated with an unmodified FMDV 3C protease on a host cell used to recombinantly produce it. Vectors carrying polynucleotides encoding modified FMDV 3C protease sequences can induce production of FMDV virus-like particles in a host cell when expressed in the host cell. The modified FMDV 3C proteases can generally be used to produce immunogenic FMDV preparations capable of inducing an immune response against FMDV.

This application is directed generally to foot-and-mouth disease virus (FMDV) 3C proteases that have been modified by mutating a polynucleotide sequence coding for the FMDV 3C protease. The modified FMDV proteases exhibit proteolytic activity on FMDV P1 precursor protein and exhibit a reduction in one or more toxic or inhibitory properties associated with an unmodified FMDV 3C protease on a host cell used to recombinantly produce it. Vectors carrying polynucleotides encoding modified FMDV 3C protease sequences can induce production of FMDV virus-like particles in a host cell when expressed in the host cell. The modified FMDV 3C proteases can generally be used to produce immunogenic FMDV preparations capable of inducing an immune response against FMDV.

A method for preparing serotype O foot-and-mouth disease virus-like particles, the method including: construction of small ubiquitin-like modifier fusion expression vector, construction of recombinant expression vectors, construction of recombinant co-expression vector, expression and purification of proteins, and in-vitro assembly of serotype O foot-and-mouth disease virus-like particles. The disclosure also provides a test strip for detecting serotype O foot-and-mouth disease including a bottom board, and a detection layer disposed on the top of the bottom board. A detection line and a control line are disposed on the detection layer. An absorbent layer is disposed at one end of the detection layer close to the control line, and an immuno-gold pad is disposed at the other side of the detection layer close to the detection line. A sample pad is disposed on the top of the immuno-gold pad.

A method for inactivated foot-and-mouth disease virus antigen purification and concentration, which relates to the field of biotechnology which includes the following steps of: (1) adding an adaptor protein with an amino acid sequence as shown in SEQ ID NO: 2 into the inactivated foot-and-mouth disease virus antigen, mixing evenly, and incubating; (2) adding a purified carrier, mixing evenly, and incubating the mixture, the purified carrier being a Lactococcus lactis skeleton; and (3) centrifuging and obtaining a precipitate.

A method for preparing serotype O foot-and-mouth disease virus-like particles, the method including: construction of small ubiquitin-like modifier fusion expression vector, construction of recombinant expression vectors, construction of recombinant co-expression vector, expression and purification of proteins, and in-vitro assembly of serotype O foot-and-mouth disease virus-like particles. The disclosure also provides a test strip for detecting serotype O foot-and-mouth disease including a bottom board, and a detection layer disposed on the top of the bottom board. A detection line and a control line are disposed on the detection layer. An absorbent layer is disposed at one end of the detection layer close to the control line, and an immuno-gold pad is disposed at the other side of the detection layer close to the detection line. A sample pad is disposed on the top of the immuno-gold pad.

The present disclosure belongs to the technical field of biological products for veterinary medicine, and specifically relates to a recombinant foot-and-mouth disease virus (FMDV) with a reduced immunosuppressive activity, a preparation method and use thereof, and a recombinant vaccine strain. According to the present disclosure, it is firstly discovered that FMDV 3B protein has an immunosuppressive function, and key sites for exerting the immunosuppressive function are found. A recombinant FMDV vaccine strain with a lost immunosuppressive function in FMDV 3B protein is constructed by introducing amino acid mutations into three repeated copies of FMDV 3B protein.

The present application relates to a method for preparing a foot-and-mouth disease (FMD) vaccine, comprising the following steps: (i) obtaining cell culture media containing FMD virus; (ii) separating and purifying the cell culture media containing FMD virus by an integrated filtration system with two membranes in combination; and (iii) collecting the concentrated solution containing FMD virus obtained in step (ii). The present application also relates to an FMD vaccine prepared by the method described herein and use thereof in the manufacture of a medicament for preventing animal FMD. The present application further relates to an apparatus for preparing an FMD vaccine, which comprises an integrated filtration system with two membranes in combination.

This application is directed generally to foot-and-mouth disease virus (FMDV) 3C proteases that have been modified by mutating a polynucleotide sequence coding for the FMDV 3C protease. The modified FMDV proteases exhibit proteolytic activity on FMDV P1 precursor protein and exhibit a reduction in one or more toxic or inhibitory properties associated with an unmodified FMDV 3C protease on a host cell used to recombinantly produce it. Vectors carrying polynucleotides encoding modified FMDV 3C protease sequences can induce production of FMDV virus-like particles in a host cell when expressed in the host cell. The modified FMDV 3C proteases can generally be used to produce immunogenic FMDV preparations capable of inducing an immune response against FMDV.

A method for inactivated foot-and-mouth disease virus antigen purification and concentration, which relates to the field of biotechnology which includes the following steps of: (1) adding an adaptor protein with an amino acid sequence as shown in SEQ ID NO: 2 into the inactivated foot-and-mouth disease virus antigen, mixing evenly, and incubating; (2) adding a purified carrier, mixing evenly, and incubating the mixture, the purified carrier being a lactococcus lactis skeleton; and (3) centrifuging and obtaining a precipitate.