Fig. 4.

Secretion of histone H1 by dendritic cells (DCs) is required for CD4⁺ T cell proliferation. (a) Histogram plots show the cell division associated with carboxyfluorescein succinimidyl ester-labelling of Piebald Virol Glaxo CD4⁺ T cells stimulated with anti-CD3 monoclonal antibody in the presence of supernatants of DCs alone or supernatant of anti-H1 antibody-DCs, supernatant of control immunoglobulin G-DCs. (b) A secreted histone H1 blockade induced by anti-histone H1 antibody reduced T cell proliferation. Data are representative of three independent experiments with essentially similar tendencies. *P < 0·05. LPS, lipopolysaccharide.