T cell suppressor factor produced by human glioblastoma cells inhibits T cell proliferation in vitro and more specifically interferes with interleukin-2 (IL-2)-dependent T cell growth.
Four patients affected by glioblastoma recurrence were treated with a gene therapy-immunotherapy protocol consisting of intratumoral injections of culture cells producing a retroviral vector which expresses human interleukin-2 and the herpes simplex virus thymidine kinase genes.
Glioblastoma cell lines transduced with this vector could produce high levels of IL-2 for up to 2 weeks, long enough to elicit an antitumor immune response.
Reverse transcription-polymerase chain reaction (RT-PCR) analysis for interleukin 4 receptor alpha (IL-4Ralpha), interleukin 13 receptor alpha1 (IL-13Ralpha1), interleukin 2 receptor gammac (IL-2Rgammac) were performed on total RNA extracted from 10 non-invasive pituitary adenomas, 30 invasive pituitary adenomas, one glioblastoma multiforme, one normal human pituitary tissue sample and one normal human brain tissue sample.