Microneme protein NcMIC3 vaccine reduces Neospora caninum infection in mice.

2003 MAY 7 - (NewsRx.com & NewsRx.net) -- Vaccination with recombinant microneme protein NcMIC3 and Ribi adjuvant reduced the incidence of cerebral infection of Neospora caninum-infected mice.

According to published research from Switzerland, "C57BL/6 mice were vaccinated with a bacterially expressed and purified polyhistidine-tagged full-length version of the microneme protein NcMIC3 (recNcMIC3) emulsified in Ribi Adjuvant System (RAS). Subsequently, they were challenged by intraperitoneal inoculation of 2 X 10[superscript]6 live Neospora caninum) tachyzoites."

"As controls, groups of mice received phosphate-buffered saline (PBS)-RAS alone (adjuvant control) or were treated with PBS before infection (infection control)," reported Angela Cannas and collaborators at the University of Bern. "The protective effect of vaccination was assessed by Neospora-specific polymerase chain reaction (PCR), immunohistochemical investigation of brain tissue, and serological means (enzyme-linked immunosorbent assay)."

"Assessment by PCR performed on DNA from different organs revealed that in all treatment groups parasite DNA could only be detected in brain tissue," said the researchers. "According to the PCR results, the recNcMIC3 vaccine conferred protection to 75% of mice (n=16 in 2 independent experiments), whereas application of PBS-RAS and of PBS alone resulted in protection of 12.5% and 0% of mice, respectively (n=16 as above). Mice in the PBS-treated infection control group were affected by evident clinical signs of neosporosis starting on day 6 postinfection (p.i.). Conversely, none of the annuals treated with either PBS-RAS or recNcMIC3 exhibited any symptoms until day 21 ...