Prevention of vertical transmission of Neospora caninum in C57BL/6 mice vaccinated with Brucella abortus strain RB51 expressing N. caninum protective antigens

Evaluation of recombinant proteins of Neospora caninum as vaccine candidates (in a mouse model)

“…Within the field of toxoplasmosis, it has received a great deal of attention because of its important role as a dense granule protein that is involved in the biology of the parasitophorous vacuole [31]. In our studies we were unable to demonstrate any evidence that this antigen is a promising vaccine candidate, even though expression in B. abortus resulted in the induction of partial protection against fetal infection in a pregnant mouse model [30]. Clearly the method of delivery of an antigen can, like many other variables in vaccination, also influence the outcome of the vaccination process.…”

“…Expression of SRS2 from live expression vectors based on vaccinia virus or Brucella abortus provided protection against fetal infection [28] or a lethal infection in mice [29]. Surprisingly SRS2 expressed in B. abortus did not provide protection against fetal infection in another study [30] and it is not clear why. In passing we note that a live B. abortus vector is unlikely to be acceptable in a commercial vaccine formulation, in particular in countries that have achieved freedom from brucellosis in their livestock.…”

Brucella abortus Strain RB51 Leucine Auxotroph as an Environmentally Safe Vaccine for Plasmid Maintenance and Antigen Overexpression

“…Recently, we have demonstrated both protective-cell-mediated immunity and antibodymediated immunity against the obligate intracellular protozoan Neospora caninum in mice by using strain RB51 as a platform for the expression of N. caninum antigens (12,13). The U.S. Food and Drug Administration discourages the use of antibiotic resistance markers for plasmid-based antigen expression in live vaccines (17).…”

The differentiation of transcription between tachyzoites and bradyzoites of in vitro cultured Neospora caninum

“…Ellis et al (2000) revealed that NcGRA2 was highly expressed in culture-derived tachyzoites. It has been known that a recombinant vaccine made of NcGRA2 and other components was able to withstand severe challenge with virulent N. caninum tachyzoite (Ramamoorthy et al 2007). In the present study, we also found that NcGRA2 is transcribed at high levels in tachyzoites.…”