Enhancing anti-melanoma activity of T-cells

From tumor immunological research it has become apparent that certain
subpopulations of T-lymphocytes of the patient can infiltrate a tumor. These
so-called Tumor Infiltrating Lymphocytes (TILs) are apparently attracked by the
tumor but also have substantial activity against these tumors. It appears that
these TILs are not fully succesful in fully eliminating the tumorcells. Derived
from recent research it became evident that patients with more TILs have a
better prognosis compared to those with less. Many attempts have been made to
use this concept of TILs in the clinic with variable succes, and in particular
in melanoma patients. TILs are first isolated from a patients' tumor, activated
outside the body and subsequently reinjected into the patient. Data from a
recent clinical trial showed that this strategy is succesful in ~20% of
patients with a more progressed stage of disease. Overall survival data
revelead that complete responders, 3-7 year survival advantage could be
reached. Nevertheless, 80% of patients with advanced disease do not respond to
this strategy. The current project develops further the concept of adoptive
T-cell transfer by increasing the efficacy of TILs. The approach is that T-cell
can be loaded with an additional effector on their surface, which enhances the
anti-tumor activity of such a pre-loaded T-cell. This effector is called TRAIL,
a protein with a strong anti-tumoricidal effect, with minimal or no activity
against healthy cells. By coupling a so-called antibody fragment to TRAIL, the
T-cell can be drapped with a multitude of the conjugates to enhance its
efficacy. In preliminary data, an enhancement of 500x can be reached by this
approach in tumor killing.

To test in vitro and in vivo therapeutic effects of new immunotherapeutic
strategies in preclinical in vitro models and in mouse models on melanoma
patient derived malignant cells.

In the current project the approach of enhancement of T-cell activity will be
investigated. In patient derived material either from primary melanoma or
metastasized melanoma, TILs will be islolated and enhanced and subsequently
tested in vitro for their efficacy on different cell lines and the
patients'melanoma cells. Furthermore, immunological cells (i.e. T-cells)
derived from peripheral blood will be isolated and tested in combination with
the tissue obtained from the same patient. for this so-called enhanced efficacy
Additionally, tissue obtained from patients will be used in mouse models to
test the anti-meloname adoptive T-cell ehanced therapy in vivo. This study will
provide us with important information on the feasibility of the proposed
approach for future clinical translation in patients. A total number of 112
samples will ne needed to analyse our primary end-point, with a total of 40 ml
of blood per patient.

During the surgical procedure, tumormaterial will be excised for
histopathological examination. Part of the material, after primary use by the
pathologist for the diagnostic process, will be used for in vitro analyses and
testing of TILs on this material. Also 4 tubes of blood (40ml/patient) will be
taken without a significant risk or burden on the patient, besides pain and
hematoma on the puncture site for blood sampling