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EP-4737567-A2 - VACCINE COMPOSITION AGAINST STREPTOCOCCUS SUIS INFECTION

EP4737567A2EP 4737567 A2EP4737567 A2EP 4737567A2EP-4737567-A2

Abstract

Described is a vaccine composition comprising an effective amount of at least one polypeptide selected from the group of IdeSsuis, rldessuis, an analogue or a fragment thereof, or a polynucleotide encoding the same. This vaccine composition is used in the prophylactic, metaphylactic or therapeutic treatment of a Streptococcus suis infections in pigs or humans.

Inventors

  • SEELE, Jana
  • BAUMS, Christoph
  • VALENTIN-WEIGAND, PETER

Assignees

  • Ceva Santé Animale S.A.

Dates

Publication Date
20260506
Application Date
20150529

Claims (9)

  1. A vaccine composition for use in a prophylactic or metaphylactic or therapeutic treatment of a Streptococcus suis infection in pigs, said vaccine composition comprising an effective amount of an IdeSSuis protein or a fragment thereof inducing neutralizing antibodies and at least a pharmaceutical carrier, a diluent or an adjuvant, wherein said protein comprises a Mac1-domain having at least 95% identity to the amino acid sequence of SEQ ID NO: 5.
  2. A vaccine composition for use of claim 1 wherein said protein has at least 95% identity to the amino acid sequence lacking the amino acids from position 1 to 34 of the amino acid sequence SEQ ID NO: 1.
  3. The vaccine composition for use of claim 2, wherein said protein comprises a Mac1-domain of SEQ ID NO: 5
  4. The vaccine composition for use according to any one of claims 1-3, wherein said protein comprises the amino acids from position 1 to 34 of the amino acid sequence SEQ ID NO: 1.
  5. The vaccine composition for use according to any one of claims 1-4 characterized in that said IdeSSuis protein or fragment thereof is part of a fusion protein with at least another protein.
  6. The vaccine composition for use according to any one of claims 1-5, characterized in that said vaccine composition is provided in a physiologically administrable form for intramuscular, intravenous, subcutaneous or dermal injection or mucosal application.
  7. The vaccine composition for use according to any one of claims 1-6, wherein the composition is configured for at least one immunization.
  8. The vaccine composition for use according to any one of claims 1-7, wherein the composition is configured for two immunizations.
  9. The vaccine composition for use according to any one of claims 1 to 8, wherein a dosage of the protein for administration per pig is 0.05 - 2.0 mg.

Description

Field of the invention The present invention relates to a vaccine composition and the use thereof for immunization and protection of mammals, in particular pigs and humans, against Streptococcus suis. Background of the invention Streptococcus suis (S. suis) colonizes the respiratory, alimentary and genital tract of pigs. S. suis is also one of the most important porcine pathogens, causing different pathologies such as meningitis, septicaemia, arthritis and endocarditis. S. suis infections account for high production losses in the swine industry worldwide. Antibiotics are commonly used to treat S. suis infections. But recurrent infections frequently occur as well as the ongoing discussions concerning the reduction of antibiotic usage underline the need for alternative control measures. In Europe, no licensed vaccine is available but autologous bacterins are commonly used. A major drawback is the fact that these vaccines protect only against the homologous serotype. But S. suis is a very diverse organism and different serotypes are responsible for morbidity in piglets. Especially serotype 2 strains play an important role for diseases in piglets worldwide. S. suis serotype 2 has been identified to cause meningitis in adults in Asia, but to date no transmission of S. suis between humans has been detected. In general infections elicit an early antigen-specific Immunoglobulin M (IgM) response leading to affinity maturation and isotope switching. Further, IgM antibodies present prior to infection, which are naturally occurring, are important in linking innate to adaptive immunity. In pigs, IgM is especially important as monomeric membrane IgM (mlgM) as it is the only B-cell receptor occurring since IgD is missing in pigs. Further, IgM synthesis in newborn piglets starts much earlier than IgG and IgA synthesis. IgM in colostrum is crucial for the protection against pathogens which is carried out by complement-mediated killing. Therefore IgM antibodies are important in the protection against different pathogens. Various virulence or virulence-associated factors of S. suis serotype 2 have been identified, among the capsule which is so far the only known essential virulence factor protecting the pathogen against phagocytosis. A number of surface-associated and secreted proteins of S. suis serotype 2 exhibit the same or very similar functions as homologous factors of other pathogenic streptococci. A variety of human or animal pathogens such as Streptococcus pyogenes, Streptococcus equi subspecies equi and Streptococcus equi subspecies zooepidemicus express specific IgG endopeptidases which are homologue to each other. A surface-associated or secreted factor with a function unique for S. suis has been firstly described by Seele et al. ("Identification of a Novel Host-specific IgM Protease in Streptococcus suis." 2013; Journal of Bacteriology, 195: 930-940). Seele et al. showed that this IgM protease, designated IdeSsuis, does not function as an IgG endopeptidase. The IgM protease degrades opsonising IgM on the bacterial surface and therefore promotes the survival of S. suis in blood of bacterin-primed piglets. IdeSsuis is highly specific for IgM and does not cleave IgG or IgA. Seele et al., however, are silent on the function of IdeSsuis, rldeSsuis and analogues and fragments thereof as effective vaccine against S. suis infections. It is merely hypothesized that neutralization of the IdeSsuis IgM protease activity might substantially improve the protective efficacy of bacterins or other future vaccines inducing opsonizing antibodies. However, it is not disclosed that IdeSsuis and related proteins may be used as the exclusive immunizing agent in a vaccine against S. suis infections. Baums et al. disclose in Surface-associated and secreted factors of Streptococcus suis in epidemiology, pathogenesis and vaccine development, Animal Health Research Reviews, Volume 10, Issue 01, June 2009, pp 65-83 bacterial factors, both surface-associated and secreted ones, which are considered to contribute to S. suis interaction(s) with host factors and cells. Factors are presented with respect to (i) their identification and features, (ii) their distribution among S. suis and (iii) their significance for virulence, immune response and vaccination. This review emphasizes the numerous challenging questions remaining to be answered in the future. The problem to be solved according to the invention is to overcome the problems described in the art and to provide a new vaccine composition to immunize and protect mammals, in particular pigs and humans, against S. suis infections. Summary of the invention This problem is solved, according to the present invention, by providing a vaccine composition which comprises an effective amount of at least one polypeptide or at least one vector selected from the group of (a) a protein designated IdeSsuis, an analogue or a fragment thereof,(b) a protein designated rldeSsuis, an analogue or a fragment thereo