Louis, MO). After incubation, all cells were collected, washed, stained with BGB324 surface markers, and analyzed by FACS. Patterns

of CD69 coexpression were determined by gating on CD3+, CD8+ T-cells. Lymphocytes were labeled with 1 μM carboxyfluorescein succinimidyl ester (CFSE) (Molecular Probes, Eugene, OR) as described previously11 and cultured for 7 days in the presence of HBV core peptide (10 μg/mL) and anti-CD244 (10 μg/mL) or anti-PD-L1/2 (5 μg/2.5 μg/mL). Plain medium, isotype control, and phytohemagglutinin (PHA) (Biochrom, Berlin, Germany) (2.4 μg/mL) served as controls. At day 3, 20 IU/mL recombinant human interleukin 2 (rhIL-2) was added. At day 7, cells were collected, washed, stained with surface markers, and analyzed by FACS. The percentage of proliferating CD8+CFSElow T-cells was determined after gating on CD3+ T-cells. In vitro expansion was performed with 2 × 106 PBMCs diluted in 1 mL culture medium. After preincubation with anti-CD244 (10 μg/mL), anti-CD48 (5 μg/mL), anti-CD244/CD48/anti-PD-L1/2 (5 μg/2.5 μg/mL) for 30 minutes at 37°C, cells were stimulated with HBV core or EBV posttranscriptional regulator protein of

EBV containing a CD8 epitope (BMFL1) peptide (10 μg/mL). At day 7, 20 IU/mL rhIL-2 was added. Isotype control and healthy donors (n = 9) served as controls. At day 21, cells were collected, washed, stained with pentamers, and analyzed by FACS. If the mean value plus 2SD in healthy individuals was exceeded, the increase of virus-specific CD8+ T-cells was defined as positive. After in vitro expansion of 3 × 106 PBMCs with HBV core or EBV peptide in the presence or absence of anti-CD244, cells were re-stimulated with or without antigen (10 μg/mL) in the presence of Monensin (2μM) and anti-CD107a

(15 μg/mL). Anti-CD3/CD28 (10 μg/mL/2 μg/mL) was used as positive control. After 6 hours of incubation, cells were collected, washed, stained with surface markers, fixed, and permeabilized. Cells were then stained with anti-IFN-γ, IL-2, and TNF-α for 20 minutes at room temperature and analyzed by FACS after a wash step. Cells were gated Selleckchem Paclitaxel on CD3+, CD8+ T-cells. Background-corrected data were shown, with subtraction of individual costimulated control sample. Data were shown as mean values. GraphPad Prism was used for analysis of the Mann-Whitney U test, Wilcoxon signed rank test, Fisher’s exact test, and Spearman correlation test. P values of less than 0.05 were considered significant. We first performed a comparative analysis of CD244 on total and HBV core (c)18-27–specific CD8+ T-cells. The characterization of CD244 distribution was done in the peripheral blood of 27 chronically infected patients, 13 acutely infected patients, 8 resolvers, and 15 healthy individuals. CD244 expression was also investigated in the liver tissue of four chronically infected patients. The mean frequency of CD8+Pentc18-27+ T-cells in chronically infected and untreated patients was 0.02%.