DNA vaccination offers the advantages of viral gene expression within host cells without the risks of infectious virus. Like viral vaccines, DNA vaccines encoding internal @entity683 virus proteins can induce immunity to conserved epitopes and so may defend the host against a broad range of viral variants. CD8(+) cytotoxic T lymphocytes (CTL) have been described as essential effectors in protection by @entity683 nucleoprotein (NP), although a lesser role of @entity1961 (+) cells has been reported. We immunized @entity19 with plasmids encoding @entity683 virus NP and matrix (M). NP + M DNA allowed B6 @entity19 to survive otherwise lethal @entity281 , but did not protect B6- @entity12812 (-/-) @entity19 defective in CD8(+) CTL. However, this does not prove CTL are required, because @entity12812 (-/-) @entity19 have @entity1200 . We used acute T cell depletion in vivo to identify effectors critical for defense against @entity281 . Since lung lymphocytes are relevant to virus clearance, surface phenotypes and cytolytic activity of lung lymphocytes were analyzed in depleted animals, along with lethal challenge studies. Depletion of either @entity1961 (+) or CD8(+) T cells in NP + M DNA-immunized BALB/c @entity19 during the challenge period did not significantly decrease survival, while simultaneous depletion of @entity1961 (+) and CD8(+) cells or depletion of all CD90(+) cells completely abrogated survival. We conclude that T cell immunity induced by NP + M DNA vaccination is responsible for immune defense, but CD8(+) T cells are not essential in the active response to this vaccination. Either @entity1961 (+) or CD8(+) T cells can promote survival and recovery in the absence of the other subset.

Vaccination with DNA encoding internal proteins of XXXX virus does not require CD8(+) cytotoxic T lymphocytes: either @entity1961 (+) or CD8(+) T cells can promote survival and recovery after challenge.

@entity19 :: ('10090', 'Species') :: ['mice'] @entity683 :: ('MESH:D007251', 'Disease') :: ['influenza'] @entity1961 :: ('12504(Tax:10090)', 'Gene') :: ['CD4'] @entity281 :: ('MESH:D007239', 'Disease') :: ['challenge infection'] @entity1200 :: ('MESH:D007154', 'Disease') :: ['multiple immune abnormalities'] @entity12812 :: ('12010(Tax:10090)', 'Gene') :: ['beta(2)m']
@entity683 :: (MESH:D007251,Disease) :: ['influenza']
