The magnitude of granzyme B production and cytotoxic capacity of HTNV-Gn/Gc-specific CD4⁺T cells.

<p>(A) Comparison of the SFC/10⁶ cells of granzyme B secreted by CD4⁺T cells specific to HTNV-Gn/Gc in ELISPOT assay between mild/moderate patients and severe/critical individuals in acute phase of HFRS. (B) The kinetics of specific lysis of peptides-pulsed target cells by the HTNV-Gn/Gc-specific CD4⁺T-cell population assessed by in vitro cell-mediated cytotoxicity assay. The CD4⁺T cells isolated from the PBMCs of the HFRS patients were used as effector cells, and the Epstein Barr Virus (EBV) transformed autologous B lymphoblastic cell line (B-LCL) or MHC class Ⅱ partial matched B-LCL of each patient pulsed with HTNV-Gn/Gc peptides were used as target cells. The effector-to-target ratios included 200:1, 100:1, 50:1, 20:1, 10:1 and 5:1. The dark spots and the circles represent the mean lysis percentage of CD4⁺T cells from mild/moderate and severe/critical patients, respectively to kill the HTNV-Gn/Gc peptides-pulsed target cells. The triangles represent the mean lysis percentage of CD4⁺T cells from all the patients to kill no peptide-pulsed target cells. The comparison of lysis percentages between the mild/moderate and severe/critical groups at each effector-to-target ratio were showed as *<i>P</i><0.05, **<i>P</i><0.01, and ns, not significant. The Wilcoxon rank sum test was used for statistical evaluation.