| Popis: |
A long-term tissue culture line of highly metastatic IR202 immunocytoma of LOU rats, and five of its clones (B4, C2, C4, C5, D3) was examined for their ability to produce cytokines. A combination of cytokine detection bioassays was employed in order to compensate for differences in sensitivity and specificity, and the possibility of inhibitors masking an activity. All the IR202 variants tested were shown to secrete constitutively varying amount of interleukin (IL-6). In addition, most of the cells produce IL-10 and TGF-beta, except clones C4 and C2, respectively. Moreover, supernatants from clone B4, C2, C4, and D3 may contain low levels of soluble IL-1. Membrane-bound IL-1 was found on the surface of B4, C4, and D3 cells. None of the IR202 variants, however, produced IL-2, IL-4, tumor necrosis factor-alpha (TNF-alpha), or LT. These results are consistent with the concept of a new type of intratumor heterogeneity and the ability of immunocytoma tumors to generate different immunoregulatory molecules in tumor-bearing hosts. |
