ISSN:
1365-3083
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Tumour regression induced in cancer patients hy local instillation of Bacillus Calmette-Guérin (BCG) into the hiadder has been considered to be mainly mediated by activated cellular immunity and inflammatory reactions. In the present study we investigated the cytotoxicity of T cells bearing γ/δ T-cell receptors (γ/δ+ T cells) against bladder carcinoma cells in vitro. Long-term cultured γ/δ+ T-cell lines from peripheral blood lymphocytes of healthy donors were established by stimulation with sonicated cell wall-associated antigens of Mycobacterium tuberculosis (SMA). These γ/δ+ T cells lack the natural killer (NK) markers CD16 and CD56, as determined by flow cytometry. The SMA-specific γ/δ+ T cells exhibited profound cytotoxicity against two NK-resistant bladder tumour cell lines as well as against NK-sensitive tumour eells in a non-major histocompatibility complex-restricted manner. The pattern of tumour cells killed by γ/δ+ T cells differed significantly from those of NK cells and lymphokine-activated killer LAK cells. Furthermore, we tested the effects of recombinant human cytokines. including interleukin (IL)-l, IL-2, IL-4, IL-6, interferon (IFN)-γ and tumour necrosis factor (TNE), on γ/δ+ T-cell-medlated cytotoxicity. It was shown that the addition of recombinant TNF in co-incubation could augment γ/δ+ T-cell-mediated killing of two bladder tumour cell lines, but not of cells of the erythroleukaemia eell line K562. Based on these results it was concluded that mycobacterial antigens could specifically activate resting γ/δ+ T cells. The cytotoxicity of γ/δ+ T cells against bladder tumour cells and its selective enhancement by TNF may bean important mechanism involved in bladder tumour regression induced by intravesical instillation of BCG.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3083.1993.tb01720.x
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