Silicone-induced T cell proliferation in mice.

Abstract

The silicone polymers used in mammary implants have been linked anecdotally to the development of autoimmune connective tissue diseases in women (1–7). Although, retrospective studies do not indicate an increased risk of developing autoimmune disease in women with silicone gel breast implants (8–10), there remains a legitimate concern among physicians and plastic surgeons alike regarding whether silicone gel breast augmentation induces and/or enhances the development of autoimmune diseases in the 1% of the population who are estimated to be genetically-susceptible. Recent studies by other labs indicate that silicone gel can enhance the production of anti-BSA antibodies in Sprague-Dawley rats and, therefore, function in an adjuvant-like manner to stimulate B cell responses (11). In this study, we demonstrate that silicone gel induces an in vitro T cell proliferative response in certain inbred strains of mice, i.e., BALB/cAnPt, (BALB/cAnPt x DBA/2N)F1 and C57BL/6, but not in DBA/2N and BALB/cJax. This response is mediated by silicone-induced peritoneal cells, which stimulate spleen, lymph and mesenteric lymph nodes cells from syngeneic mice injected subcutaneously with silicone gel, pristane or thioglycollate but not with Hank’s balanced salt solution (HBSS). In contrast, pristane, thioglycollate or HBSS-generated peritoneal cells do not induce T-cell proliferation. In BALB/c mice, this response is dose dependent, enhanced by enrichment of CD4+ cells (stimulation index > 9.0) and inhibited with antibodies to either IL-2 or IL-4. Environmental factors play a critical role in the development of a T cell response, since neither specific pathogen-free (SPF)-BALB/c mice nor conventionally-housed (CON) BALB/c mice maintained on a low-fat diet respond well to silicone. These results demonstrate that silicone-induced T cell proliferation in mice is mediated nonspecifically by CD4+ Th cells and is influenced by both genetic and environmental factors.KeywordsLymph Node CellStimulation IndexPeritoneal CellAugmentation MammoplastyMesenteric Lymph Node CellThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.