Immunization against Anaplasma phagocytophilum Adhesin Binding Domains Confers Protection against Infection in the Mouse Model [Cellular Microbiology: Pathogen-Host Cell Molecular Interactions]

In this study, C57BL/6 mice were immunized with a cocktail of keyhole limpet hemocyanin-conjugated peptides corresponding to the AipA, Asp14, and OmpA binding domains in alum followed by challenge with A. phagocytophilum. The bacterial peripheral blood burden was pronouncedly reduced in immunized mice compared to controls. Examination of pre- and postchallenge sera from these mice revealed that immunization elicited antibodies against AipA and Asp14 peptides but not OmpA peptide. Nonetheless, pooled sera from pre- and postchallenge groups, but not from control groups, inhibited A. phagocytophilum infection of HL-60 cells. Adhesin domain immunization also elicited interferon gamma (IFN-)-producing CD8-positive (CD8+) T cells. A follow-up study confirmed that immunization against only the AipA or Asp14 binding domain was sufficient to reduce the bacterial peripheral blood load in mice following challenge and elicit antibodies that inhibit A. phagocytophilum cellular infection in vitro. These data demonstrate that AipA and Asp14 are critical for A. phagocytophilum to productively infect mice, and immunization against their binding domains elicits a protective immune response.
Source: Infection and Immunity - Category: Infectious Diseases Authors: Tags: Cellular Microbiology: Pathogen-Host Cell Molecular Interactions Source Type: research