RESUMEN
Dendritic cells (DCs) are potent antigen-presenting cells which are key leukocytes in the initiation of cell-mediated organ graft rejection, antiviral immunity, and antitumor responses. In this study we demonstrate that genetic modification of primary human and mouse DCs by adenoviral gene transfer is an effective means of induction and modulation of antigen presentation by DCs. An adenovirus vector (AdLacZ) was used to express an intracellular model antigen beta-galactosidase (beta-gal) in DCs. Our results show that 30-40% of precursor dendritic cells (PDCs) derived from human umbilical cord blood and circulating mature blood DCs express high levels beta-galactosidase (beta-gal) after infection with AdLacZ with no cytopathic effect observed. In vitro, AdLacZ transduced PDCs and DCs demonstrated a 10- to 20-fold higher mixed lymphocyte reaction (MLR) stimulatory capacity as compared to that of monocytes. In vivo, immunization with AdLacZ transduced mouse DCs resulted in more potent cytotoxic T lymphocyte (CTL) responses against the predicted H-2 restricted beta-gal epitope as compared to CTL responses obtained by beta-gal peptide pulsed DCs. Modulations of the MLR stimulatory capacity of DCs were examined by expression of mouse B7 and CTLA-4Ig. The results show that expression of mouse B7 by a recombinant adenoviral vector (Ad7) significantly enhances the MLR stimulatory capacity of human DCs. In contrast, expression of CTLA-4Ig (AdCTLA-4Ig) reduces the MLR stimulatory capacity of the transduced cells. We conclude that recombinant adenovirus can readily be used for genetic modulation DC-induced immune responses in vivo and in vitro. DCs targeted for induction of specific antigen responses or for modulation of the immune stimulatory capacity may have a potential use in the control of transplantation rejection or viral infections.
Asunto(s)
Adenoviridae/genética , Células Dendríticas/inmunología , Transducción Genética , Animales , Presentación de Antígeno/genética , Secuencia de Bases , Cartilla de ADN/genética , Expresión Génica , Técnicas de Transferencia de Gen , Ingeniería Genética , Vectores Genéticos , Humanos , Técnicas In Vitro , Operón Lac , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Linfocitos T Citotóxicos/inmunologíaAsunto(s)
Antivirales/uso terapéutico , Infecciones por Citomegalovirus/prevención & control , Ganciclovir/uso terapéutico , Trasplante de Riñón , Administración Oral , Infecciones por Citomegalovirus/epidemiología , Relación Dosis-Respuesta a Droga , Femenino , Estudios de Seguimiento , Humanos , Fallo Renal Crónico/etiología , Fallo Renal Crónico/cirugía , Masculino , Persona de Mediana Edad , Proyectos Piloto , Complicaciones Posoperatorias , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND: In clinical transplantation, "passenger" dendritic cells (DCs) in the allograft have been thought to induce allograft rejection. However, the presence of DCs in the normal human kidney is controversial. Most reports have relied on the examination of MHC class I and II antigen expression in combination with DC morphology for identification of DCs. METHODS: The distribution of the p55 antigen (fascin), which is selectively expressed by human blood and lymphoid DCs, was investigated by immunohistochemistry. RESULTS: Our study demonstrates that p55-positive DCs are absent from the normal human kidney and CD1a- and S100-positive cells are absent or very rare. Furthermore, HLA-DR and factor VIII-related antigen show almost complete colocalization in capillaries. In contrast, all 16 kidney biopsies from patients with inflammatory processes demonstrated p55-positive DCs in the cellular infiltrates. CONCLUSIONS: These results suggest that DCs are not present or are very rare in normal renal tissues but may migrate into the renal interstitium with inflammatory changes.