Anti-interleukin-10R1 monoclonal antibody enhances bacillus Calmette-Guérin induced T-helper type 1 immune responses and antitumor immunity in a mouse orthotopic model of bladder cancer.

PURPOSE: Proper induction of the T-helper type 1 immune response is required for effective bacillus Calmette-Guérin immunotherapy for bladder cancer. Interleukin-10 down-regulates the T-helper 1 response and is associated with bacillus Calmette-Guérin failure. We investigated whether blocking interleukin-10 receptor 1 would enhance the bacillus Calmette-Guérin induced T-helper type 1 immune response and anti-bladder cancer immunity in a mouse model. MATERIALS AND METHODS: Splenocytes were incubated with bacillus Calmette-Guérin or bacillus Calmette-Guérin plus control IgG1, anti-interleukin-10 receptor 1 mAb or anti-interleukin-10 neutralizing mAb, followed by enzyme-linked immunosorbent assay of interferon-γ production. Bladder RNA was extracted after intravesical bacillus Calmette-Guérin plus intraperitoneal IgG1 or anti-interleukin-10 receptor 1 mAb and analyzed by reverse transcriptase and/or quantitative polymerase chain reaction. Urine was collected and analyzed by enzyme-linked immunosorbent assay. Mice bearing a luciferase expressing MB49 orthotopic tumor were treated with intravesical bacillus Calmette-Guérin plus intraperitoneal IgG1 or anti-interleukin-10 receptor 1 mAb. Tumor response was assessed by bioluminescent imaging and bladder weight measurement. RESULTS: Bacillus Calmette-Guérin plus anti-interleukin-10R1 mAb induced significantly higher interferon-γ production by splenocytes than bacillus Calmette-Guérin plus anti-interleukin-10 mAb. Bacillus Calmette-Guérin plus anti-interleukin-10 receptor 1 mAb also induced significantly higher interferon-γ mRNA and protein in bladder and urine, respectively, in a dose dependent manner. Treatment with phosphate buffered saline, bacillus Calmette-Guérin plus control IgG1 and bacillus Calmette-Guérin plus anti-interleukin-10 receptor 1 mAb showed a 0% tumor-free rate with a 20% death rate, a 20% tumor-free rate with a 20% death rate and a 40% tumor-free rate with a 0% death rate, respectively. Bladder weight also revealed the effect of anti-interleukin-10 receptor 1 mAb on the bacillus Calmette-Guérin induced bladder tumor response. CONCLUSIONS: Anti-interleukin-10 receptor 1 mAb enhanced the bacillus Calmette-Guérin induced T-helper type 1 immune response and anti-bladder cancer immunity. A humanized form of this mAb warrants future investigation for bacillus Calmette-Guérin treatment of bladder cancer.

Novel chimeric genotype 1b/2a hepatitis C virus suitable for high-throughput screening.

A major obstacle in hepatitis C virus (HCV) research has been the lack of a permissive cell culture system that produces infectious viral particles. Significant breakthroughs have been achieved lately in establishing such culture systems. Yet to date, there are no reports of the applications of any of these systems in HCV drug screening. Here, we report the generation of two monocistronic, chimeric genotype 1 full-length HCV genome molecules. These molecules, C33J-Y835C-UBI and C33J-Y835C-FMDV2A, both contain the structural protein region from genotype 1 (subtype 1b, Con1) and the remaining region from the genotype 2a (JFH1) clone. Both contain the humanized Renilla luciferase reporter gene which is separated from the rest of the HCV open reading frame by two different cleavage sites. The viral RNAs replicated efficiently in transfected cells. Viral particles produced were infectious in naïve Huh7.5 cells, and the infectivity could be blocked by monoclonal antibody against a putative HCV entry cofactor, CD81. A pilot high-throughput screen of 900 unknown compounds was executed by both the genotype 2a subgenomic replicon system and the infectious system. Thirty-one compounds were identified as hits by both systems, whereas 78 compounds were identified as hits only for the infectious system, suggesting that the infectious system is capable of identifying inhibitors targeting the viral structural proteins and steps involving them in the viral life cycle. The infectious HCV system developed here provides a useful and versatile tool which should greatly facilitate the identification of HCV inhibitors currently not identified by the subgenomic replicon system.