Methods and compositions for inducing immune responses against Clostridium difficile
Inventors
Tian, Jing-Hui • Liu, Ye • Smith, Gale • Glenn, Gregory • Flyer, David
Assignees
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Publication Number
US-11938179-B2
Publication Date
2024-03-26
Expiration Date
Abstract
Disclosed herein are methods and compositions for treating or preventing bacterial infection. In particular, the methods and compositions are directed towards C. difficile infection. In particular aspects, the compositions are vaccines containing multimeric polypeptides containing portions of multiple toxins from bacteria. The polypeptides induce effective immune responses thus treating or preventing infection.
Core Innovation
The invention relates to vaccines and immunization methods against Clostridium difficile infection using multivalent immunogenic polypeptide constructs. The polypeptides comprise a binary toxin (CDT) portion and C. difficile Toxin A and two Toxin B portions, expressed as soluble, multimeric toxin fusion proteins. The approach is directed to inducing neutralizing antibodies and protecting against lethal toxin challenge.
The document emphasizes insect-cell expression of the multimeric toxin fusion proteins and handling that preserves nanoparticle integrity. Nanoparticle formation and preservation are described in connection with production of large multimer proteins from insect cells, and nanoparticle characterization is discussed, including dynamic light scattering and particle diameter ranges.
Example constructs are described as chimeric trivalent (T-toxin) and quadrivalent (Q-toxin) fusion proteins built from C. difficile toxin components, including TcdA, TcdB, and CDT components/CDTb. The document also describes immunogenic compositions including alum and saponin-based Matrix-M™ formulated with Fraction A Matrix and Fraction C Matrix, together with ISCOM and ISCOM matrix complexes and saponin fractions derived from Quillaja saponaria Molina.
Claims Coverage
The claims center on one multivalent immunogenic polypeptide containing four C. difficile toxin-derived portions, with sequence homology requirements and arrangement features. Additional claims refine linker length and immunogenic compositions with specified adjuvant components.
Multivalent immunogenic polypeptide with specified toxin portions and sequence homology
A multivalent immunogenic polypeptide comprising a binary toxin (CDT) portion, a Toxin A portion, a first Toxin B portion, and a second Toxin B portion, each from a C. difficile toxin protein and each defined by SEQ ID NO: 22, 24, 23, and 25 or amino acid sequences having at least 90% homology to those sequences.
Higher homology thresholds for each toxin portion
The CDT portion, Toxin A portion, first Toxin B portion, and second Toxin B portion each have amino acid sequences at least 97% homologous to SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 23, and SEQ ID NO: 25, respectively.
Uniform high homology across all toxin portions
The CDT portion, Toxin A portion, first Toxin B portion, and second Toxin B portion each have amino acid sequences at least 98% homologous to SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 23, and SEQ ID NO: 25, respectively.
Toxin A portion positioned between two Toxin B portions
The multivalent immunogenic polypeptide is arranged so that the Toxin A portion lies between two Toxin B portions.
Portion separation by short linkers
Each peptide portion is separated by a linker consisting of two, three, or four amino acids.
Saponin-based adjuvant with Fraction A Matrix and Fraction C Matrix
An immunogenic composition in which a saponin-based adjuvant includes Fraction A Matrix and Fraction C Matrix.
The claims cover a multivalent immunogenic polypeptide including CDT, Toxin A, and two Toxin B portions from C. difficile, with specified sequence homology thresholds, positional arrangement, short linkers, and immunogenic compositions formulated with saponin-based adjuvants containing Fraction A Matrix and Fraction C Matrix.
Stated Advantages
Inducing neutralizing antibodies.
Protecting against lethal toxin challenge.
Documented Applications
Vaccines and immunization methods against Clostridium difficile infection using multivalent immunogenic polypeptide constructs.
Neutralizing-antibody-associated protection assessed by lethal toxin challenge in C57BL/6 mice and golden Syrian hamsters.
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