Cellular immune reactivities in women with silicone breast implants: a preliminary investigation.

BACKGROUND: Surgical implantation of silicone breast prostheses has been conducted and considered safe for over 30 years. Some implant recipients, however, complain of a group of symptoms similar to those observed in connective tissue disorders, rheumatoid arthritis, systemic lupus erythematosus, or polymyositis. To date, immunologic sequelae have not been confirmed and remain controversial. OBJECTIVE: To examine an autoimmune-like basis for the "silicone associated disease" reported by some women with silicone breast prostheses. METHODS: Proliferative responses of peripheral blood mononuclear cells against a panel of control and connective tissue proteins and to compounds common to silicone prostheses were measured in 26 women who received silicone breast implants (with implants in place an average of 166.4 [standard deviation (SD) 58.3] months), and 23 age-matched and sex-matched healthy controls. RESULTS: The frequency and intensity of cellular immune responses against collagen I, collagen III, fibrinogen, and fibronectin were significantly increased in silicone breast implant recipients versus controls. In implant subjects, the highest frequency of immune reactivity was directed against collagen I (11/26, 42%) with collagen III being the most immunostimulatory self-antigen with a mean stimulation index (SI) of 8.2 [95% confidence interval (95% CI) 3.2]. In addition, 10/26 (39%) of the implant recipients responded to more than one of the connective tissue antigens versus 0/23 (0%, P = .0007) healthy controls. Immunologic reactivities to other antigens, including silicone-based compounds, were remarkably similar. CONCLUSIONS: The identification of self-reactivity towards these connective tissue antigens may provide important information for attempts at associating silicone breast implants with disease.

Identification of a salivary agglutinin-binding domain within cell surface adhesin P1 of Streptococcus mutans.

DNA encoding the alanine-rich region (A-region) of the cell surface adhesin, P1, from Streptococcus mutans was subcloned and expressed as a fusion protein with the maltose-binding protein (MBP) of Escherichia coli. The A-region fusion protein was shown to competitively inhibit both adherence of S. mutans to salivary agglutinin-coated hydroxyapatite and fluid-phase agglutinin-mediated aggregation of this organism. MBP alone or an MBP-paramyosin fusion protein was not inhibitory. Proteolytic cleavage of the fusion protein into its component moieties, MBP and A-region, resulted in breakdown of the A-region into three main fragments. Western immunoblot analysis of calcium-dependent agglutinin binding to this preparation revealed binding specificity for a 28-kDa fragment. Thus, the A-region of P1 is an important domain which interacts directly with salivary agglutinin, and this interaction interferes with both the aggregation and the adherence mechanisms in vitro.

Differentiation of salivary agglutinin-mediated adherence and aggregation of mutans streptococci by use of monoclonal antibodies against the major surface adhesin P1.

The ability to adhere to salivary agglutinin-coated hydroxyapatite beads and to aggregate in the presence of fluid-phase salivary agglutinin was tested by using 25 isolates of mutants streptococci representing eight serotypes. Both adherence and aggregation activity correlated with expression of the Mr-185,000 cell surface antigen P1 on Streptococcus mutans serotype c, e, and f strains. In addition, it was shown that the P1 molecule itself served as the adhesin of S. mutans serotype c, since adherence was significantly inhibited by the presence of recombinant-specified Mr-150,000 P1. The ability of S. sobrinus strains to adhere or aggregate did not correlate with expression of the P1 cross-reactive antigen SpaA. There was also evidence for interaction with salivary agglutinin, as manifested by aggregation but not adherence of S. rattus serotype b, which does not express a P1 cross-reactive antigen. To understand the interaction of P1 with salivary agglutinin at the molecular level, a panel of 11 anti-P1 monoclonal antibodies was tested for inhibitory activity in adherence and aggregation inhibition assays. Overlapping, but not identical, subsets of monoclonal antibodies were found to inhibit adherence and aggregation, indicating that the interactions of P1 with salivary agglutinin which mediate these two phenomena are different. The localization of functional domains of P1 which may mediate the aggregation and adherence reactions is discussed.

Identification of monoclonal antibody-binding domains within antigen P1 of Streptococcus mutans and cross-reactivity with related surface antigens of oral streptococci.

Eleven monoclonal antibodies (MAbs) specific for P1, the major protein surface antigen of Streptococcus mutans serotype c, were characterized by Western blot (immunoblot) analysis and by radioimmunoassay using whole bacterial cells. The approximate binding domains of the MAbs were determined by using full-length and truncated P1 polypeptides. The accessibility of these binding sites on the surfaces of intact bacteria was determined by radioimmunoassay. The ability of each MAb to cross-react with related proteins from strains of S. mutans serotypes e and f, S. sanguis, and S. sobrinus serotype g is also reported.

Construction and characterization of isogenic mutants of Streptococcus mutans deficient in major surface protein antigen P1 (I/II).

The gene (spaP) coding for the Streptococcus mutans major surface protein antigen P1 (or I/II) has been cloned into Escherichia coli (S. F. Lee, A. Progulske-Fox, and A. S. Bleiweis, Infect. Immun. 56:2114-2119, 1988). In the present study, this gene has been disrupted in vitro by insertional inactivation with pVA981, which carries a Tcr marker, and transformed into S. mutans NG8 (serotype c) by electroporation. Upon homologous recombination, the defective spaP was integrated into the genome as demonstrated by Southern hybridization analysis. One Tcr mutant, designated 834, selected by its nonreactivity with anti-P1 monoclonal antibodies, was found to lack the cell surface fuzzy layer which was clearly present on the parent cells. Analysis of extracellular fluids, sodium dodecyl sulfate-solubilized membranes, and cytoplasmic fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that 834 had protein profiles identical to the parent. However, a 185-kilodalton protein which reacts with anti-P1 antibodies was missing from the wall of 834, suggesting that spaP has been specifically inactivated. This mutant displayed levels of glucosyltransferase and fructosyltransferase activities similar to those of the parent. It was much less hydrophobic than the parent. S. mutans NG8 aggregated readily in the presence of clarified whole saliva or a high-molecular-weight salivary agglutinin. This strain also adhered to agglutinin-coated hydroxyapatite. The P1-negative mutants, however, did not display these two properties, suggesting that P1 may play a role in saliva-mediated aggregation and adherence.