Assembly of wild-type and chimeric influenza virus-like particles (VLPs)
Influenza virus-like particles (VLPs) comprising the structural proteins HA, NA, M1 and M2 are described. VLPs are also generated containing M1 alone, as are VLPs with M1 and any one or two of HA, NA and M2. VLPs with HA from one influenza subtype and NA from a different influenza subtype are also described, as are VLPs in which a portion or all of HA or NA is replaced by a heterologous moiety not produced by influenza virus, so as to comprise chimeric VLPs.
1. A method of production of influenza virus-like particles (VLPs), said method consisting of the steps of:
(i) constructing a recombinant DNA molecule which in terms of influenza virus proteins encodes only the influenza virus matrix structural protein (M1);
(ii) constructing one or more recombinant DNA molecules which each encode at least one of but no more than all of the influenza virus structural proteins selected from the group consisting of hemagglutinin (HA), neuraminidase (NA) and the spliced product of M1 mRNA (M2);
(iii) transfecting, infecting or otherwise transforming a suitable host cell with said recombinant DNA molecules referred to under (i) and with the recombinant DNA molecules referred to under (ii), culturing the host cell under conditions which permit the expression of said influenza virus structural proteins, so that VLPs are assembled within the cells after expression of the influenza virus structural proteins; and
(iv) purifying the VLPs from the culture supernatant.
2. The method of claim 1 where HA and NA are from different subtypes of influenza virus.
3. A method of production of chimeric influenza virus-like particles (VLPs), said method consisting of the steps of:
(i) constructing a recombinant DNA molecule which in terms of influenza virus proteins encodes only the influenza virus matrix structural protein (M1);
(ii) constructing one or more recombinant DNA molecules which each encode at least one of but no more than all of the influenza virus structural proteins selected from the group consisting of hemagglutinin (HA), neuraminidase (NA) and the spliced product of M1 mRNA (M2), except wherein a portion or all of the HA or NA DNA sequences have been replaced by a DNA sequence which encodes a non-influenza moiety;
(iii) transfecting, infecting or otherwise transforming a suitable host cell with the recombinant DNA molecules referred under (i) and with the recombinant DNA molecules referred to under (ii), culturing the host cell under conditions which permit the expression of said influenza virus structural proteins so that VLPs are assembled within the cells after expression of the influenza virus structural proteins; and
(iv) purifying the VLPs from the culture supernatant.
4. The method of claim 3 where the DNA sequence in the recombinant DNA molecule which encodes the HA is replaced by a DNA sequence which encodes the G protein of Vesicular stomatitis virus (VSV).
5. The method of claim 3 where the DNA sequence in one recombinant DNA molecule encodes the transmembrane and cytoplasmic domains of HA, but the remaining coding region of HA is replaced by a DNA sequence which encodes the ectodomain of the G protein of VSV.
6. A method of production of influenza virus-like particles (VLPs), said method consisting of the steps of:
(i) constructing a recombinant DNA molecule which in terms of the influenza virus protein encodes only the influenza virus matrix structural protein (M1);
(ii) constructing one or more recombinant DNA molecules which each encode at least one of but no more than all of the influenza virus structural proteins selected from the group consisting of hemagglutinin (HA), neuraminidase (NA) and the spliced product of M1 mRNA (M2);
(iii) transfecting, infecting or otherwise transforming a suitable host cell with the recombinant DNA molecules referred to under (i) and with the recombinant DNA molecules referred to under (ii), culturing the host cell under conditions which permit the expression of said influenza virus structural proteins, so that VLPs are assembled within the cells after expression of the influenza virus structural proteins: and co-transfecting, co-infecting or co-transforming the host cell with a recombinant DNA molecule which in terms of influenza virus proteins encodes only the influenza nucleocapsid protein (NP), so that NP is co-localized with the M1 structural protein, and
(iv) purifying the VLPs from the culture supernatant.
7. A method of production of influenza virus-like particles (VLPs), said method consisting of the steps of:
(i) constructing a recombinant DNA molecule which in terms of influenza virus proteins encodes only the influenza virus matrix structural protein (M1);
(ii) constructing one or more recombinant DNA molecules which each encode at least one of but no more than all of the influenza virus structural proteins selected from the group consisting of hemagglutinin (HA), neuraminidase (NA) and the spliced product of M1mRNA (2);
(iii) transfecting, infecting or otherwise transforming a suitable host cell with the recombinant DNA molecules referred to under (i) and with the recombinant DNA molecules referred to under (ii), culturing the host cell under conditions which permit the expression of said influenza virus structural proteins, so that VLPs are assembled within the cells after expression of the influenza virus structural proteins; and co-transfecting, co-infecting or co-transforming the host cell with a recombinant DNA molecule which encodes only a moiety not produced by influenza virus, so that the non-influenza moiety is encapsulated within the VLPs or is incorporated into the surface of the VLPs, and
(iv) purifying the VLPs from the culture supernatant.