After washes, the number of tumor-infiltrated CD8+, CD4+Foxp3− and CD4+Foxp3+ cells were analyzed using flow cytometry assay and the following antibodies: FITC-labeled anti-mouse CD8, FITC-labeled anti-mouse CD4 (both from BD Biosciences) and PE-labeled anti-mouse Foxp3 mAb (eBiosciences), and appropriate
FITC- and PE-labeled isotype control Ab (BD Biosciences). see more The level of CD4+Foxp3+ cells (Treg cells) was also evaluated in spleens of tumor-bearing treated and control mice using the same flow cytometry assay. The expression of PDL-1 on the surface of TC-1 cells was detected by flow cytometry using anti-PDL-1 (CD274) mAb (eBiosciences). Briefly, confluent TC-1 cells were trypsinized, left for an hour on ice and stained with PE-labeled anti-mouse PDL-1 antibody for 30 min at 4oC. After washing, surface expression of PDL-1 on TC-1 cells was analyzed using FACScan flow cytometer and CellQuest software (BD Biosciences). The ability of CT-011 antibody to inhibit the TC-1 tumor-mediated suppression of CD4+CD25− T-cell proliferation was assessed by carboxyfluorescein
diacetate, succinimidyl ester (CFSE)-based suppression assay. The CD4+CD25− T (Tconv) cells were purified from the spleens of naïve mice using the Militenyi Biotec MACS T-cell purification kit as suggested by the manufacturer. Cells were labeled with 1 μM CFSE dye as suggested by the manufacturer (Invitrogen), as suggested by the manufacturer. After washes, CFSE-labeled Tconv cells were stimulated with α-CD3 α-CD28 polystrene dynal beads Wnt drug (Invitrogen) and co-incubated with TC-1 cells at a 1:1 ratio for 4 days, alone or
in the presence of 50 μg/mL concentrations of CT-011 antibody, PDL-1-IgG protein or isotype control antibody. After washes, samples were evaluated for CFSE dye dilution using FACScan flow cytometer and CellQuest software (BD Biosciences). All Erastin cost statistical parameters (average values, SD, significant differences between groups) were calculated using the GraphPad Prism Software. Statistical significance between groups was determined by one-way ANOVA with Tukey’s multiple comparison post-test (p<0.05 was considered statistically significant). The authors thank Daniel O'Mard, Ashley Reynolds and Gail McMullen from the NIH animal facility for their technical assistance with animal injections. This work was supported by the Intramural Research Program of the Center for Cancer Research, NCI, NIH. Conflict of interest: R. R. Y. is an employee of CureTech Ltd., which provided CT-011. The remaining authors declare no financial or commercial conflict of interest. "
“Th1 CD4+ T cells and their derived cytokines are crucial for protection against Mycobacterium tuberculosis.