Generation of precursor T cells dor the development of adoptive T cell therapy for patients after stem cell transplantation.

The central aim of this project is to improve immune reconstitution and
decrease the morbidity of patients that have received a hematopoietic stem cell
transplant (HSCT) in line with their anti-cancer treatment. Even thought HSCT
cures patients from cancer, there is a delay in generation of pro-thymocytes
that are required to initiate T cell production by the thymus. The enduring T
cell lymphopenia causes that too many patients die because of oppurtunistic
infections.

The ultimate goal is to develop an early T cell reconstition therapy to combine
with HSCT to treat and cure patients with hematological cancers. In this stage,
thus for this project, we need to investigate if we can make in vitro T cell
from CD34+ hematopoietic stem cells in a GMP compliant system. We can isolate
these stem cells from leucaferesis products obtained from healthy volunteers
treated with G-CSF.

This study concerns only in vitro experiments which will be performed with stem
cells obtained from leucaferis product from healthy volunteers.
CD34+ stem cells will be isolated from the leucaferesis product. In vitro
experiments will be performed with the stem cells to investigate whether they
have T cell potential. The cells will be discarded after analysis.

The extent of the burden is low. The study will only be of short duration.
Before the start of the study, the volunteer will be medically examined. This
will take approximately 30 minutes. During 5 days the donor will inject
him/herself subcutaneous with G-CSF, this can be performed at home. The donor
will be instructed about this procedure. Hereafter the leucaferese will follow,
this will take about 4 hours. Needles will be placed in both arms, therefore
the donor is not able to move a lot during the 4 hours. The procedure is
already carried out in the hospital as a standard for stem cell
transplantation. Therefore, the staff will be familiar with the procedure. This
will comfort the donor and if side effects appear the doctor can act fast.

G-CSF is normally well taken. It can cause temporary discomfort:

- 80% of the donors have bone pain and/or headache. 25% suffers from muscle
ache.
- 0.1-1% suffers from spleen abnormalities, among which an enlarged spleen and
very rare rupture.
- In rare cases donors can experience cardiac complaints. This is only observed
in donors with cardiac risk factors.

The leucaferesis itself is of low burden. Side effects can be a tingling
feeling near the mouth and in the fingertips. This can be ended by giving the
donor calcium. For example by giving the donor milk or yoghurt.
Some donors endure fatigue after the leucaferesis.