Catherine Uyttenhove

Stimulation of Cytolytic T Lymphocytes By Azaguanine-resistant Mouse-tumor Cells in Selective Hat Medium

Primed syngeneic or unprimed allogeneic mouse spleen cells were stimulated with azaguanine-resistant P815 tumor cells that were killed by the addition of aminopterin to the stimulation medium. The recovery of lymphocytes and their cytolytic activity and specificity were similar to those obtained after stimulation with irradiated cells. This method conveniently replaces the inactivation of stimulatory cells by irradiation or mitomycin treatment. Moreover, it has the advantage of inactivating not only the stimulatory cells but also the tumor cells that often contaminate the spleens of tumor-bearing animals, provided these animals have been inoculated with azaguanine-resistant tumor cell mutants.

Biology of Interleukin 9 and its Receptor

The first description of IL9 was based on the observation that supernatants of activated helper T-cell clones were capable of supporting the long term growth of certain T-cell clones in the absence of antigen and antigen presenting cells (Uyttenhove 1988). The protein responsible for this activity, designated P40 on the basis of its apparent size in gel filtration, was characterized by an elevated pI (~10) and a high level of glycosylation. Partial amino acid sequences allowed the screening of a cDNA library with oligonucleotides and the cloning of a full length clone encoding the murine P40 protein (Van Snick 1989). Subsequently, the cDNA of the human homologue was isolated by cross-species hybridization (Renauld 1990a,b), while Yang (1989) isolated the human IL9 cDNA by expression cloning of a factor stimulating the growth of the Mo7E megakaryoblastic leukemia line.