Adenoviruses are a family of viruses that can cause colds,
conjunctivitis or gastroenteritis. However, these viruses, once modified
to acquire selectivity towards tumor cells, have great potential to be
used as cancer therapy.
Oncolytic adenoviruses are viruses that are modified to
exclusively attack cancer cells without attacking normal tissue, like a
targeted therapy. There are several limitations in this field; one of them is our own
immune system, which recognizes the virus as a pathogen and therefore
‘An oncolytic virus capable of redirecting the patient's immune system against their tumor cells has been developed by researchers of the Cancer Virotherapy Research Group of Bellvitge Biomedicine Research Institute.’
Researchers of the Cancer Virotherapy Research Group of Bellvitge
Biomedicine Research Institute (IDIBELL), led by Dr. Ramon Alemany, have
developed an oncolytic virus capable of redirecting the patient's
immune system against their tumor cells. Their work, published in the Cancer Research
journal, may lead to the development of new therapeutic strategies for several types of cancer.
Carlos Fajardo, lead author of the study, explains, "What we are trying to do is redirect the immune system to
attack the cancer cells instead of the virus. In this way, we not only
prevent the virus from being eliminated from the organism too soon, but
complement its action by adding that of T lymphocytes."
To achieve this, the researchers used the newly developed BiTE
antibodies (bispecific T-cell engager antibodies). These antibodies are
capable of specifically connecting T lymphocytes with some proteins
expressed on the surface of cancer cells; this connection activates the T
cell, which then attacks and destroys the tumor cell.
"We modified the virus so that when it infects the tumor cell, it
secretes a specific BiTE against the EGFR protein, which is
overexpressed in many types of cancer". In in vitro studies, the
research team found that these BiTEs were able to capture the T
lymphocytes present in the medium to attack adjacent cancer cells. In
addition, mouse studies demonstrated that the virus armed with BiTE were
able to increase the presence of T lymphocytes in tumors, resulting in
improved antitumor efficacy.
At the moment virotherapy in cancer is a very active field in
research thanks to the advances in immunotherapy developed in recent
years. "With these results, we will try to attract the interest of the
companies that develop BiTEs to establish collaboration agreements for
the clinical development of viruses armed with BiTEs," added Dr.
Alemany, the last author of the study. "We are also exploring the
development of viruses that target T lymphocytes against tumor stroma
fibroblasts to eliminate them".