Tumour cells engineered to secrete interleukin-15 augment anti-tumour immune responses in vivo

We examined the effect of interleukin-15 (IL-15) gene transfer into tumour cells on the host's anti-tumour response. In BALB/c mice IL-15 producing Me th-A cells (Meth-A/IL-15) underwent complete rejection, in a response chara cterized by massive infiltration of CD4(+) T-cells and neutrophils. In cont rast, Meth-A cells transfected with vector alone (Meth-A/Neo) grew rapidly. Moreover, rechallenged parental cells also were rejected in association wi th CD8(+) T-cell infiltration. However, in nude mice there was no drastic d ifference between Meth-A/IL-15 and Meth-A/Neo cells. These results demonstr ate that IL-15-secreting tumour cells can stimulate local and systemic T-ce ll-dependent immunity and therefore may have a potential role in cancer the rapy.