Fig. 3
Cytokine production by peripheral and intrahepatic Vδ1 T lymphocytes. Production of interferon-γ (IFN-γ) and interleukin-4 (IL-4) was determined at the single-cell level by intracellular staining with specific anti-bodies (mAbs) after stimulation with (PMA) and ionomycin. 106 peripheral blood mononuclear cells (PBMC) and 2 × 105 intrahepatic lymphocytes (IHL) were stimulated for 6 hr in the presence of brefeldin. (A) The percentage of IFN-γ-producing-Vδ1 T lymphocytes was evaluated in peripheral blood from healthy donors. Moreover, the frequency of Vδ1 T lymphocytes was monitored in PBMC and IHL of hepatitis C virus-positive (HCV+) persons presenting (A) low inflammation (1 < Gr < 2, n = 4) or (B) high inflammation of the liver (Gr > 4, n = 5). (B) The same analysis was performed to determine the percentage of IL-4-producing Vδ1 T lymphocytes. Results are expressed as arithmetic mean percentage ± standard deviation (SD) of positive cells among peripheral (white bars) and liver infiltrating (hatched bars) Vδ1+ T cells. Significance refers to Student’s t-test. p-values are indicated as follows: * = p < 0.04. Gr: Grading.