Circovirus sequences associated with piglet weight loss disease (PWD)
The genome sequences and the nucleotide sequences coding for the PWD circovirus polypeptides, such as the circovirus structural and non-structural polypeptides, vectors including the sequences, and cells and animals transformed by the vectors are provided. Methods for detecting the nucleic acids or polypeptides, and kits for diagnosing infection by a PWD circovirus, also are provided. Method for selecting compounds capable of modulating the viral infection are further provided. Pharmaceutical, including vaccine, compositions for preventing and/or treating viral infections caused by PWD circovirus and the use of vectors for preventing and/or treating diseases also are provided.
1. An isolated hybrid polypeptide comprising:
i) at least one polypeptide encoded by a nucleotide sequence of the genome of porcine circovirus type B (PCVB), wherein polypeptide i) comprises a PCVB antigen or epitope thereof that induces an immune response in a porcine animal and wherein the nucleotide sequence consists of a sequence which has at least 90% identity to SEQ ID NO: 25; and
ii) a sequence of a second polypeptide that induces an immune response in a porcine animal, wherein sequence ii) comprises an additional viral or bacterial antigen.
2. The isolated polypeptide of claim 1 , wherein polypeptide i) is a polypeptide having the amino acid sequence of SEQ ID NO. 26.
3. The isolated polypeptide of claim 1 , wherein polypeptide i) is in glycosylated form.
4. The isolated polypeptide of claim 1 , wherein the antigen of sequence ii) comprises a viral or bacterial toxin.
5. The isolated polypeptide of claim 1 , wherein sequence ii) comprises an epitope of the diphtheria toxin, the tetanus toxin, a surface antigen of the hepatitis B virus, or the VP1 antigen of the poliomyelitis virus.
6. An immunogenic composition comprising the isolated polypeptide of claim 1 and a pharmaceutically acceptable carrier.
7. A vaccine comprising the isolated polypeptide of claim 1 and a pharmaceutically acceptable carrier.
8. A method comprising:
contacting a biological sample with an isolated polypeptide according to claim 1 under conditions allowing an immunological reaction between said polypeptide and the antibodies possibly present in the biological sample; and
detecting the antigen-antibody complexes possibly formed.
9. The method of claim 8 , wherein the biological sample is formed by a serum, whole blood, or biopsies.
10. The method of claim 8 , wherein detection of the antigen-antibody complexes possibly formed is by the ELISA technique, by immunofluorescence, or by radioimmunological processes (RIA) or their equivalent,.
11. The method of claim 8 , comprising:
deposition of determined quantities of a composition comprising the isolated polypeptide of claim 1 in the wells of a microtiter plate;
introduction into said wells of increasing dilutions of a biological sample formed by a serum to be analyzed;
incubation of the microtiter plate;
introduction into the wells of labeled antibodies directed against immunoglobulins, the labeling of the antibodies having been carried out with the aid of an enzyme capable of hydrolyzing a substrate; and
detection, by comparison with a control test, of the quantity of hydrolyzed substrate.