Fig. 6
From: CEACAM1 promotes CD8+ T cell responses and improves control of a chronic viral infection
Treatment with anti-hCEACAM1 mAb improves CD8+ T cell function in human cells. a Representative fluorescence-activated cell sorting (FACS) histogram (left panel) showing CEACAM1 expression and mean fluorescence intensity (MFI) levels (right panel) of naïve CD8+ T cells from the peripheral blood of healthy donors (n = 10). b, c Intracellular cytokine (interferon-γ (IFN-γ)) secretion by peripheral blood mononuclear cells (PBMCs) from healthy donors that were cultured with Flu peptide together with anti-CD28 antibody (b) or with or without cytomegalovirus (CMV) peptide (c) and human interleukin-2 (IL-2) in the presence or absence of anti-hCEACAM1 antibody (40 µg ml–1; clone 18/20) for 10 days. Cytokine production was assessed by restimulation of PBMCs with or without Flu peptide (b, n = 8–10 per group) for 6 h or with CMV peptide (c; n = 9 per group) for 8 h at 37 °C, as measured with flow cytometry. d Histogram showing mean fluorescence intensity (MFI) levels of CEACAM1 expression in peripheral blood CD8+ (left panel) and CD4+ (right panel) T cells from hCeacam1+/+ × msCeacam1–/– mice as measured by flow cytometry (n = 4–5 per group). e Experimental setup. Human CEACAM1 transgenic mice (hCeacam1+/+ × msCeacam1–/–) were injected with anti-hCEACAM1 antibody (clone 18/20) or isotype antibody on day –1 (100 µg/mouse) and day 3 (200 µg/mouse), followed by infection with 2 × 104 PFU of LCMV-Docile on day 0. f Number of virus-specific Tet-GP33+ (left panel) and NP396+ (right panel) CD8+ T cells in blood from hCeacam1+/+ × msCeacam1–/– mice on day 8 after infection (n = 5 per group). *P < 0.05, **P < 0.01, ***P < 0.001; ****P < 0.0001 (Student’s t test). Data are representative of two (a, d, f) or three (b, c) experiments (mean ± SEM; a–d, f)
