PB301 Target Overview

  • Limitations of stem cell therapy

    • Mesenchymal stem cells (MSC) can be obtained from bone marrow, fat, umbilical cord tissue, etc., and have the ability to regulate immune cells in addition to pluripotency to differentiate into specific tissues.
    • It has been reported that mesenchymal stem cells have an immunosuppressive effect, but there is a possibility of immune rejection, and their viability is rapidly reduced by complement in serum.
    • Exosomes secreted by mesenchymal stem cells have similar effects to those of original cells and are attracting attention as an alternative to cell therapy.
  • Possibility of stem cell therapy using exosomes

    • Exosomes are extracellular vesicles (EVs) that are released from cells and exist in most body fluids in the form of membranous vesicles of about 50-200 nm.
    • Exosomes are composed of a phospholipid bilayer, so even if they are released out of the cell due to changes in the microenvironment, such as cell activity, stress, or damage, they protect physiologically active substances such as protein, mRNA, and miRNA from immune components in the body.
    • It is known that various types of immune cells, tumor cells, and stem cells produce and secrete exosomes while they are alive. In particular, stem cell-derived exosomes contain receptors and proteins as well as nuclear components, allowing cell-to-cell communication.
    • The efficacy of MSC-exosomes on Th17 cells, which play a key role in the onset and exacerbation of autoimmune diseases, and their molecular mechanisms have not been extensively studied.

MoA & Indication of PB301

Target (MoA)

- Various Th17 cell targeting treatments using MSC-exosomes

- Target : Th17 cell

- MoA :

  • Decreased stability of RORγt, a transcription factor in Th17 cells
  • Selectively inhibits the differentiation of Th17 cells and the production of IL-17A
  • Induces dedifferentiation that loses the functions and properties of Th17 cells

- Autoimmune disease

  • Rheumatoid arthritis
  • Systemic lupus erythematosus
  • Multiple sclerosis
  • Psoriasis
  • Chronic inflammatory bowel disease

Th17 cell-mediated autoimmune disease

  • Patent

    No.1067742, 2011.09.20.

  • Domestic patent registration

    Human neural stem cell-derived immunomodulatory microvesicles and uses thereof.

  • Patent

    No.10-2017-0048667, 2018.04.16.

  • Patent application

    Treatment of autoimmune diseases involving MSC-exosomes.