RESUMO
Most hepatocellular carcinomas (HCCs) express oncofetal alpha-fetoprotein (AFP). We and others have demonstrated efficient tumor control mediated by cellular immune responses in mice bearing subcutaneous tumors derived from the AFP-expressing murine HCC cell line Hepa 1-6 by DNA vaccination against AFP. In the present study, we examined AFP DNA vaccination in the AFP-expressing primary murine HCC model BW7756. In this model AFP DNA vaccination resulted in only minimal lymphocytic infiltration and failed to control tumor growth. To augment the AFP-specific cellular immune response, intratumoral expression of chemokine IP-10 (interferon-inducible protein-10) and the proinflammatory cytokine interleukin (IL)-12 by adenoviral vectors (AdmIL-12 and AdmIP-10) was analyzed. Intratumoral injection of AdmIL-12 and AdmIP-10 resulted in transient tumor regressions, without prolongation of animal survival. By contrast, AFP DNA vaccination followed by intratumoral injection of AdmIL-12 and AdmIP-10 resulted in tumor regression in all animals and in prolongation of animal survival; in 25% of animals the tumors became undetectable. This study demonstrates for the first time that activation of effector cells against a tumor antigen induced by the combination of DNA vaccination and intratumoral chemokine and cytokine expression is superior to the respective treatment strategies alone. This effect may be mediated by attraction of activated effector cells to the tumor tissue.
Assuntos
Adenoviridae/genética , Carcinoma Hepatocelular/terapia , Quimiocinas/metabolismo , Citocinas/metabolismo , Imunoterapia/métodos , Neoplasias Hepáticas Experimentais/terapia , Vacinas de DNA/administração & dosagem , alfa-Fetoproteínas/genética , Animais , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/mortalidade , Linhagem Celular Tumoral , Quimiocina CXCL10/metabolismo , Citocinas/genética , Modelos Animais de Doenças , Terapia Genética , Interleucina-12/genética , Interleucina-12/metabolismo , Neoplasias Hepáticas Experimentais/imunologia , Neoplasias Hepáticas Experimentais/metabolismo , Neoplasias Hepáticas Experimentais/mortalidade , Camundongos , Resultado do Tratamento , Vacinação , Vacinas de DNA/genética , alfa-Fetoproteínas/metabolismoRESUMO
OBJECTIVE: Perforin is an important component of the death machinery of cytotoxic T cells (CTL). To evaluate functional differences between HIV- and cytomegalovirus (CMV)-specific CTL of coinfected patients, the frequencies of the respective perforin-expressing T cells were analysed in a rapid whole blood assay. METHODS: Whole blood of HIV- and CMV-infected individuals was specifically stimulated by HIV-1 Pr55(gag) or complete CMV antigen, and activation-induced intracellular cytokine and perforin expression in CD8 T cells was analysed by flow cytometry. RESULTS: Perforin-expressing HIV-1- and CMV-specific CD8 T cells can be quantified simultaneously. Within a patient, the frequency of such HIV-specific CD8 T cells in peripheral blood was lower than the frequency of the respective CMV-specific cells. The number of the perforin-expressing HIV-specific CD8 T cells inversely correlated with the peripheral blood CD4 T cell count. CONCLUSIONS: The differential fractions of perforin-expressing virus-specific CD8 T cells in HIV and CMV double infection might be caused by differences in priming and trafficking to or from replication sites. However, without knowing the underlying mechanism, the fraction of perforin-expressing HIV-specific CD8 T cells provides another surrogate marker for disease progression.
