The invention relates to methods and compositions for preventing or treating a
neuropathology in a subject associated with or induced or caused by a P. gingivalis infection, preventing the deposition of or reducing the level of P. gingivalis gingipain in neuronal tissue, delaying the onset of a P. gingivalis-induced or associated
neuropathology, for preventing or slowing the rate of
abnormal protein deposition in the neuronal tissue, and / or reducing
neuroinflammation, the methods comprising administering an
RNA polynucleotide encoding a
protein comprising or consisting of: - one or more
amino acid sequences of an
active site of an Arg- or Lys-gingipain of P. gingivalis, or a sequence that is at least 80% identical thereto; and / or - the
amino acid sequence of one or more adhesin binding motifs (ABMs) of an adhesin domain of an Arg- or Lys-gingipain of P. gingivalis, or a sequence that is at least 80% identical thereto, wherein the
polynucleotide is capable of being translated in a
mammalian cell.