Interleukin-10 expressed at early tumour sites induces subsequent generation of CD4+ T-regulatory cells and systemic collapse of antitumour immunity
Article first published online: 21 DEC 2001
Volume 103, Issue 4, pages 449–457, August 2001
How to Cite
Seo, N., Hayakawa, S., Takigawa, M. and Tokura, Y. (2001), Interleukin-10 expressed at early tumour sites induces subsequent generation of CD4+ T-regulatory cells and systemic collapse of antitumour immunity. Immunology, 103: 449–457. doi: 10.1046/j.1365-2567.2001.01279.x
- Issue published online: 21 DEC 2001
- Article first published online: 21 DEC 2001
- Received 19 February 2001; revised 14 May 2001; accepted 14 May 2001.
We investigated the relationship between transforming growth factor-β (TGF-β)-secreting T-regulatory (Tr) cells and anti-B16 melanoma immunity, and studied the association of early cytokines expressed at tumour sites with the generation of Tr cells. A large number of CD4+ Tr cells producing interleukin (IL)-4, IL-10 and TGF-β accumulated with functionally depressed CD8+ cytotoxic T lymphocytes (CTLs) at tumour sites on day 20 after subcutaneous (s.c.) inoculation of B16 tumour cells. Tr cells consisted of two populations, which were termed T helper 3 (Th3) and Tr1 cells. B16-infiltrating Tr cells strongly inhibited the generation of B16-specific T helper 1 (Th1) cells in a TGF-β-dependent manner and were assumed to suppress effective generation of CTLs. In addition, B16 cells markedly progressed in mice transferred adoptively by the cultured B16-infiltrating Tr cells compared with untreated mice. The capacity of these Tr cells to produce TGF-β was hampered by neutralizing anti-IL-10 and partly anti-IL-4 monoclonal antibodies (mAbs) injected intralesionally during the early development of B16 tumours, and this treatment markedly attenuated B16 growth. Furthermore, a lesional injection of recombinant mouse IL-10 at an early tumour site resulted in the vigorous progression of B16 tumours. These results provide evidence that Tr cells, belonging to the T helper 3/T-regulatory 1 (Th3/Tr1) type, are activated in B16-bearing hosts under the influence of T helper 2 (Th2) cytokines, mainly IL-10 (produced at early tumour lesions), and that this regulatory T-cell population functions as a suppressor of anti-B16 immunity.