A vaccination strategy incorporating DNA priming and mucosal boosting using XXXX toxin fragment C (TetC).

@entity19 @entity9686 @entity60 @entity116 @entity9749
Intramuscular (i.m.) immunisation of BALB/c @entity19 with a DNA vaccine, pcDNA3/tetC, encoding fragment C (TetC) from @entity116 toxin, stimulated production of TetC specific @entity9749 antibodies in the serum and release of @entity60 from TetC stimulated splenocytes. A similar pattern of immune response was detected if pcDNA3/tetC primed @entity19 were boosted i.m. with purified TetC protein or TetC and cholera toxin (included as an adjuvant). In contrast, control @entity19 primed with the empty DNA vector pcDNA3 and boosted i.m. with TetC or TetC and CT, generated a dominant @entity9686 specific anti-TetC response in the sera and low or undetectable levels of @entity60 from stimulated splenocytes. Thus, i.m. priming with a DNA vaccine modulated the subsequent immune response to the same antigen administered as a protein boost. Similar observations were made when DNA primed @entity19 were boosted using the intranasal mucosal route of immunisation. Interestingly, although @entity19 immunised with pcDNA3/tetC and boosted mucosally with TetC and CT produced anti-TetC IgA in mucosal secretions, the titres were reproducibly lower than those detected in @entity19 immunised with the pcDNA3 vector alone. The immunomodulatory effect of pcDNA3/tetC appeared to be antigen specific as mucosal boosting with an unrelated antigen (pertactin) revealed no significant modulation in terms of the anti-pertactin immune response.
