Expression of vFLIP in a lentiviral vaccine vector activates NF-{kappa}B, matures dendritic cells, and increases CD8+ T-cell responses

TY - JOUR

T1 - Expression of vFLIP in a lentiviral vaccine vector activates NF-{kappa}B, matures dendritic cells, and increases CD8+ T-cell responses

AU - Rowe, Helen M

AU - Lopes, Luciene

AU - Brown, Najmeeyah

AU - Efklidou, Sofia

AU - Smallie, Timothy

AU - Karrar, Sarah

AU - Kaye, Paul M

AU - Collins, Mary K

PY - 2009/2

Y1 - 2009/2

N2 - Lentiviral vectors deliver antigens to dendritic cells (DCs) in vivo, but they do not trigger DC maturation. We therefore expressed a viral protein that constitutively activates NF-kappaB, vFLIP from Kaposi's sarcoma-associated herpesvirus (KSHV), in a lentivector to mature DCs. vFLIP activated NF-kappaB in mouse bone marrow-derived DCs in vitro and matured these DCs to a similar extent as lipopolysaccharide; costimulatory markers CD80, CD86, CD40, and ICAM-1 were upregulated and tumor necrosis factor alpha and interleukin-12 secreted. The vFLIP-expressing lentivector also matured DCs in vivo. When we coexpressed vFLIP in a lentivector with ovalbumin (Ova), we found an increased immune response to Ova; up to 10 times more Ova-specific CD8(+) T cells secreting gamma interferon were detected in the spleens of vFLIP_Ova-immunized mice than in the spleens of mice immunized with GFP_Ova. Furthermore, this increased CD8(+) T-cell response correlated with improved tumor-free survival in a tumor therapy model. A single immunization with vFLIP_Ova also reduced the parasite load when mice were challenged with OVA-Leishmania donovani. In conclusion, vFLIP from KSHV is a DC activator, maturing DCs in vitro and in vivo. This demonstrates that NF-kappaB activation is sufficient to induce many aspects of DC maturation and that expression of a constitutive NF-kappaB activator can improve the efficacy of a vaccine vector.

AB - Lentiviral vectors deliver antigens to dendritic cells (DCs) in vivo, but they do not trigger DC maturation. We therefore expressed a viral protein that constitutively activates NF-kappaB, vFLIP from Kaposi's sarcoma-associated herpesvirus (KSHV), in a lentivector to mature DCs. vFLIP activated NF-kappaB in mouse bone marrow-derived DCs in vitro and matured these DCs to a similar extent as lipopolysaccharide; costimulatory markers CD80, CD86, CD40, and ICAM-1 were upregulated and tumor necrosis factor alpha and interleukin-12 secreted. The vFLIP-expressing lentivector also matured DCs in vivo. When we coexpressed vFLIP in a lentivector with ovalbumin (Ova), we found an increased immune response to Ova; up to 10 times more Ova-specific CD8(+) T cells secreting gamma interferon were detected in the spleens of vFLIP_Ova-immunized mice than in the spleens of mice immunized with GFP_Ova. Furthermore, this increased CD8(+) T-cell response correlated with improved tumor-free survival in a tumor therapy model. A single immunization with vFLIP_Ova also reduced the parasite load when mice were challenged with OVA-Leishmania donovani. In conclusion, vFLIP from KSHV is a DC activator, maturing DCs in vitro and in vivo. This demonstrates that NF-kappaB activation is sufficient to induce many aspects of DC maturation and that expression of a constitutive NF-kappaB activator can improve the efficacy of a vaccine vector.

KW - Animals

KW - CD8-Positive T-Lymphocytes

KW - Cancer Vaccines

KW - Cytokines

KW - Dendritic Cells

KW - Leishmania donovani

KW - Leishmaniasis

KW - Lentivirus

KW - Mice

KW - NF-kappa B

KW - Neoplasms

KW - Ovalbumin

KW - Receptors, Immunologic

KW - Spleen

KW - Survival Analysis

KW - Viral Proteins

KW - Viral Vaccines

U2 - 10.1128/JVI.00709-08

DO - 10.1128/JVI.00709-08

M3 - Article

C2 - 19036811

SN - 0022-538X

VL - 83

SP - 1555

EP - 1562

JO - JOURNAL OF VIROLOGY

JF - JOURNAL OF VIROLOGY

IS - 4

ER -