Biobank for personalized immunotherapy: storage of immune cell-derived microvesicles and plasma

Aging of the immune system inevitably results in weakening both protective and regenerative capabilities of the organism, with T-cell-mediated immunity being particularly affected in older people. Indeed, «old» T lymphocytes exhibit a decreased ability to recognize different pathogens and to support regenerative processes. In turn, B-cell-mediated immunity suffers from functional T-cell abnormalities that prevent normal B cell functions. Non-specific anti-infective protection is also subject to deterioration due to the diminished metabolic activity of leukocyte phagocyte cells. Hence, aging of the immune system makes the organism defenseless against infectious, cancer and autoimmune diseases.

Extracellular microvesicles are released into cell culture medium by activated and apoptotic (i.e. dying) cells. Microvesicles are capable of mirroring entirely functional immune cell-dependent effects, which rationalises their application in immunotherapy in this project. Indeed, upon administration, microvesicles could effectively penetrate via biological barriers and accumulate in target tissues and organs alike. In contrast to donor cells, exovesicles: (i) cannot inflict immunological rejection phenomena, (ii) cannot induce graft versus host disease (GvHD), and (iii) are less demanding in terms of storage and transport requirements. We have developed a novel technology that allows to prepare immunoactive microvesicles from blood cells under controlled conditions. We showed that such microvesicles are capable of mobilising the patient’s immune system for combatting invading pathogens within short periods of time. Our innovative cell cryopreservation technology permits the application of aytological or donor immunoactive material in such dire situations when intrinsic protective resources are reduced owing to aging or disease.

Functions of the immunological biobank:

• Storage of plasma (or serum) with well-characterised (or pre-programmed) immunological properties;
• Storage of microvesicles derived from leukocytes or other blood cells.

Finally we consider it to be extremely relevant and important to preserve immune microvesicles and plasma derived from patients recovered from an infectious disease, such as recent COVID-19. Indeed, this biological material would be indispensable in treating viral and bacterial infections affecting people with weakened immune systems.