Spontaneous resistance to acute T-cell leukaemias in TCRVγ1.1Jγ4Cγ4 transgenic mice

Abstract

THE concept of tumour surveillance implies that specific and nonspecific components of the immune system eliminate tumours in the early phase of malignancy^1,2. The immunological mechanisms that control growth of preneoplastic cells are, however, not known. T cells expressing γδ T-cell receptors (TCR) were first described as lymphocytes with reactivity against various tumour cells, which suggests that γδ T cells could mediate tumour surveillance^3–6. Here we show that TCRVγ1.1Jγ4Cγ4 transgenic mice⁷ are spontaneously resistant to acute T-cell leukaemias but cannot reject non-haematopoietic tumours. TCRVγ1.1Jγ4Cγ4⁺ hybridomas isolated from these mice react in vitro against almost all haematopoietic tumour cell lines tested. Recognition of tumour cells depends on the γδ TCR but is independent of major histocompati-bility complex (MHC) class I, MHC class II, or TAP-2 peptide transporter expression. Ligand recognition is influenced by the murine Nromp gene, which confers resistance or susceptibility to tuberculosis, lepra and leishmaniasis^8,9. These data indicate that TCRVγ1.1⁺ T cells confer spontaneous immunity against haematopoietic tumours in vivo and link innate resistance to bacterial infections with tissue-specific tumour surveillance by γδ⁺ T cells.