H. Plotnicky et al., IL-2-DEPENDENT HTLV-I-INFECTED T-CELLS ESCAPE FROM NONSPECIFIC, MHC-UNRESTRICTED CELLULAR CYTOTOXICITY, Clinical immunology and immunopathology, 73(2), 1994, pp. 205-214
The susceptibility of NK cell-mediated cytolysis was compared between
5 human HTLV-I-transformed T cell lines and 10 newly established IL-8-
dependent HTLV-I-infected lines. None of the cell lines were killed af
ter 4 hr incubation with normal PBMC. However, after 20 hr, 3 HTLV-I-t
ransformed lines were significantly lysed. All the HTLV-I-infected lin
es, except 2, weakly inhibited the NK cell-mediated lysis of K562 targ
ets. They showed a reduced ability to bind normal PBMC as compared wit
h control NK-sensitive T cell lines. The IL-8-dependent lines remained
unaffected by PBMC from HTLV-I-infected individuals, including the au
tologous donors. In contrast to the HTLV-I-transformed lines, they wer
e weakly lysed or not lysed at all by LAK cells and only 5 were killed
by ADCC with HTLV-I+ sera and normal PBMC. Taken together, the result
s show that IL-8-dependent HTLV-I-infected T cells strongly resist NK
cell-mediated cytolysis at a post-binding level and suggest that such
cells may escape in vivo from non-specific, MHC-unrestricted cellular
cytotoxicity. (C) 1994 Academic Press, Inc.