Generation of Powerful Human Tolerogenic Dendritic Cells by Lentiviral-Mediated IL-10 Gene Transfer

Abstract

The prominent role of dendritic cells (DC) in promoting tolerance and the development of methods to generate clinical grade products allowed the clinical application of tolerogenic DC (tolDC)-based therapies for controlling unwanted immune responses. We established an efficient method to generate tolerogenic human DC, producing supra-physiological levels of IL-10, by genetically engineering monocyte-derived DC with a bidirectional Lentiviral Vector (bdLV) encoding for IL-10 and a marker gene. DC IL−10 are mature DC, modulate T cell responses, promote T regulatory cells, and are phenotypically and functionally stable upon stimulation. Adoptive transfer of human DC IL−10 in a humanized mouse model dampens allogeneic T cell recall responses, while murine DC IL−10 delays acute graft-vs.-host disease in mice. Our report outlines an efficient method to transduce human myeloid cells with large-size LV and shows that stable over-expression of IL-10 generates an effective cell product for future clinical applications in the contest of allogeneic transplantation.

Regulatory Dendritic Cells, T Cell Tolerance, and Dendritic Cell Therapy for Immunologic Disease

“…In contrast to IL-10-lentivirustransfected murine DCreg, which induce differentiation of CD25 + Foxp3 + Treg (159), the IL-10-lentivirus-transfected human DCreg instead induced the development of Tr1 responses (149). Interestingly, however, while the numbers of Tr1 marker-positive cells were differentially affected by the microbial agonists added to the human DCreg-T cell cultures, marked differences in the suppressive activities or cytokine profiles of the Tr1 cells so induced were not observed (149). The recognition that our microbiome contributes importantly to our overall health has brought its impact on immune regulation by DC into focus.…”

“…Table 2 provides data from human DCreg generated from CD14 + monocytes in vitro , and includes the agents used to induce and mature the cells, the phenotype of the DCreg, the mechanisms by which they induce their immunologic effects and whether they activate Treg. While the regulatory activities for most of these cells were assessed exclusively in vitro , the IL-10-lentivirus-tranfected human DC10 were also assessed for their abilities to protect humanized otherwise immunocompromised mice from graft-versus-host disease ( 149 ).…”

“…In a similar manner, delivery of the dectin-1/TLR2 agonist curdlan ( 181 ), a bacterial cell wall exopolysaccharide, to asthmatic mice induces differentiation of IL-10-expressing, Maf + Foxp3 − Treg (i.e., Tr1 cells), and thereby reverses the animal’s asthma phenotype ( 182 ). On the other hand, human IL-10-lentivirus-transfected DCreg display very complex responses to microbial agonists ( 149 ), including polyinosinic:polycytidylic acid (Poly I:C), LPS, flagellin and CpG (agonists specific for TLR3, TLR4, TLR5, and TLR9, respectively), as well as Listeria monocytogenes ( 149 ). The authors of this report found that a number of classical DCreg markers were differentially regulated on exposure to these agonists.…”

Regulatory Cell Therapy in Organ Transplantation: Achievements and Open Questions

“…We and others developed IL-10-modulated DC ( 31 , 73 – 75 ), and comparative analysis of DC-10, IL-10-modulated DC generated in vitro through the exposure of monocytes to IL-10 during DC differentiation ( 31 ), and IL-10-DC, monocyte-derived DC exposed to IL-10 during the last 2 days of DC differentiation ( 73 ), demonstrated that both cell types inhibited primary allogeneic T cell responses, but DC-10 were more effective in promoting allo-specific Tr1 cells in vitro (Gregori S. et al, personal communication). More recently, an efficient protocol to generate IL-10-producing human DC (DC IL−10 ) through the transduction of monocytes with a LV encoding for IL-10 has been established ( 76 ). DC IL−10 secrete supra-physiological levels of IL-10, are stable upon exposure to pro-inflammatory signals, recapitulate the tolerogenic ability of DC-10, and inhibited allogeneic T cell responses in vivo ( 76 ).…”

“…More recently, an efficient protocol to generate IL-10-producing human DC (DC IL−10 ) through the transduction of monocytes with a LV encoding for IL-10 has been established ( 76 ). DC IL−10 secrete supra-physiological levels of IL-10, are stable upon exposure to pro-inflammatory signals, recapitulate the tolerogenic ability of DC-10, and inhibited allogeneic T cell responses in vivo ( 76 ).…”