Antibodies raised against a fimbriated, adhesive strain of Streptococcus sanguis (FW213) were found to block the adhesion of this organism to saliva-coated hydroxyapatite. Antibodies were made specific for adhesion antigens by adsorption with isogenic, nonadhesive mutants (for rabbit polyclonal adsorbed antibody) or selection based on nonreactivity with two nonadhesive mutants (for monoclonal antibody). Rabbit antibody raised against isogenic, nonfimbriated nonadhesive mutants served as a control for antibodies present, but not related to fimbriation. Adsorbed antibody and monoclonal antibody were shown to be specific for fimbriae (antigen 1), since both antibodies could be seen by immune electron microscopy to bind 3.6-nm fimbriae, reacted only with the fimbriated parent and not the mutants in a whole bacterial cell enzyme-linked immunosorbent assay, and could immunoprecipitate fimbriae from fimbrial extracts of FW213. Antibodies isolated from preimmune and mutant sera did not react with fimbriae in any of the above assays. Only adsorbed antibody and monoclonal antibody were capable of blocking the adhesion of FW213 to saliva-coated hydroxyapatite. Adsorbed antibody, purified to immunoglobulin G (IgG), was an effective inhibitor of adhesion without causing interfering cellular aggregation. Monoclonal IgG, papain-cleaved to Fab fragments to prohibit cell-to-cell cross-linking, was also a potent inhibitor of S. sanguis FW213 adhesion. Both IgG from mutant sera and Fab fragments from normal mouse IgG could not be shown to block adhesion. These data further support the hypothesis that S. sanguis fimbriae are involved in adhesion.

IMPORTANCE New treatments are needed to improve the prognosis of patients with recurrent high-grade glioma.OBJECTIVE To compare overall survival for patients receiving tumor resection followed by vocimagene amiretrorepvec (Toca 511) with flucytosine (Toca FC) vs standard of care (SOC). DESIGN, SETTING, AND PARTICIPANTSA randomized, open-label phase 2/3 trial (TOCA 5) in 58 centers in the US, Canada, Israel, and South Korea, comparing posttumor resection treatment with Toca 511 followed by Toca FC vs a defined single choice of approved (SOC) therapies was conducted from November 30, 2015, to December 20, 2019. Patients received tumor resection for first or second recurrence of glioblastoma or anaplastic astrocytoma.INTERVENTIONS Patients were randomized 1:1 to receive Toca 511/FC (n = 201) or SOC control (n = 202). For the Toca 511/FC group, patients received Toca 511 injected into the resection cavity wall at the time of surgery, followed by cycles of oral Toca FC 6 weeks after surgery. For the SOC control group, patients received investigators' choice of single therapy: lomustine, temozolomide, or bevacizumab. MAIN OUTCOMES AND MEASURESThe primary outcome was overall survival (OS) in time from randomization date to death due to any cause. Secondary outcomes reported in this study included safety, durable response rate (DRR), duration of DRR, durable clinical benefit rate, OS and DRR by IDH1 variant status, and 12-month OS. RESULTSAll 403 randomized patients (median [SD] age: 56 [11.46] years; 62.5% [252] men) were included in the efficacy analysis, and 400 patients were included in the safety analysis (3 patients on the SOC group did not receive resection). Final analysis included 271 deaths (141 deaths in the Toca 511/FC group and 130 deaths in the SOC control group). The median follow-up was 22.8 months. The median OS was 11.10 months for the Toca 511/FC group and 12.22 months for the control group (hazard ratio, 1.06; 95% CI 0.83, 1.35; P = .62). The secondary end points did not demonstrate statistically significant differences. The rates of adverse events were similar in the Toca 511/FC group and the SOC control group.CONCLUSIONS AND RELEVANCE Among patients who underwent tumor resection for first or second recurrence of glioblastoma or anaplastic astrocytoma, administration of Toca 511 and Toca FC, compared with SOC, did not improve overall survival or other efficacy end points.

The inflammatory and immune responses seen with the worldwide disease scabies, caused by the mite Sarcoptes scabiei (De Geer) (Acari: Sarcoptidae), are complex. Clinical symptoms are delayed for weeks in patients when they are infested with scabies for the first time. This study was undertaken to elucidate the role of the human dermal microvascular endothelial cell (HMVEC-D) in modulating the inflammatory and immune responses in the skin to S. scabiei. Extracts of S. scabiei were incubated with HMVEC-D and the expression of adhesion molecules and chemokine receptors on the cells and the secretion of selected cytokines were determined by enzyme-linked immunosorbent assay. S. scabiei extract was found to inhibit HMVEC-D expression of E-selectin and vascular cell adhesion molecule-1, although not intercellular adhesion molecule-1. The secretion of interleukin-8 also was inhibited by S. scabiei extract. S. scabiei extract increased expression of the chemokine receptor CXCR-1 and both down-regulated and up-regulated expression of CXCR-2, depending on the concentration tested. These findings help explain the delayed inflammatory reaction to infestation with S. scabiei.

No abstract

Monoclonal antibodies reactive to an adhesive strain of Streptococcus sanguis (FW213) and nonreactive to a nonadhesive mutant (JL7) were derived from the fusion of myeloma line X63Ag8.653 and spleen cells from BALB/c mice immunized with live S. sanguis cells. Five cell lines, belonging to subclasses of immunoglobulin G, produced monoclonal antibodies specifically directed against the adhesive strain. All five antibodies also failed to react with five additional, independently isolated, nonadhesive mutants. A spontaneous mutant of FW213 (VT508) that no longer reacted with monoclonal antibody F51 (MAbF51) was isolated by serial agglutination with the antibody. Langmuir adsorption isotherms of VT508 indicated that this mutant also had altered ability to adhere to saliva-coated hydroxyapatite further confirming the specificity of MAbF51 for adhesion. Electron microscopy revealed that VT508 had lost the peritrichous fimbriae associated with the adhesion of FW213. MAbF51 was used to purify the adhesin from lysozyme cell extracts by using an affinity column of MAbF51 linked to Sephacryl S1000. Purity was suggested by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and crossed immunoelectrophoresis (CIEP). The adhesin had a molecular weight greater than 150,000 and was not denatured in sodium dodecyl sulfate reducing gels. Two peaks of near electrophoretic mobility were detected in CIEP when the purified material was run against polyclonal antibody to the whole cell. Tandem CIEP analysis and immunoprecipitation provided evidence that the two peaks represented the same antigen in two different forms.