ABSTRACT
Type 1 diabetes is an autoimmune disorder characterized by the reduced production of insulin due to the depletion of β cells located in the pancreatic islets of Langerhans. This disease, typically, occurs during the childhood.
Genetic, environmental and immunological factors are recognized risk factors for this pathology. The routine treatment is the injection of exogenous insulin. Many research centers, all over the world, are studying alternative treatments based on the transplantation of the pancreas (highly invasive and expensive) or the infusion of pancreatic β cells. Unfortunately most of these cells are rejected by the autoimmune response. It is therefore necessary to develop novel strategies to preserve the transplanted β cells.
The aim of this work is to develop a lentiviral vector to engineer human mesenchymal stem cells from umbilical cord (HUC-MSC) in such a way to constitutively express viral the Epstein-Barr virus interleukin-10 (vIL10). The v-IL10 is similar to the human IL-10 but is devoid of immunostimulating activity. In fact, vIL-10 inhibits cell-mediated immunity and inflammation and promotes the humoral response. The transduced cells will be then co-transplanted in the omental pouch with β cells of pancreatic islets. We have chosen a lentiviral vector derived from feline immunodeficiency virus (FIV) because is incapable to replicate in human cells.
In addition to v-IL 10, the vector encodes for the TK (thymidine kinase) from Herpes Simplex virus, which allows an in vivo screening of the cells that have incorporated the construct. These two genes will be connected by an internal ribosome entry side that makes possible the translation of both genes from the same messenger RNA.
The vector produced here is capable to release vIL-10 in supernatants of transfected HEK 293T (human embryonic kidney cell line. We are currently developing an assay to assess the functional activity of this cytokine.
This vector will be then transduced in HUC-MSC and the engineered cells will be then tested for the ability to preserve the β cells from autoimmunity.
