Histamine induce the activation of specific TCD8+ cells through increase cross-presentation.

AMARAL MARÍA M; ANA CEBALLOS; PETRACCA YANINA; SALAMONE GABRIELA; NAHMOD KAREN; MAGGINI JULIÁN; SABATTE JUAN; GEFFNER JORGE; VERMEULEN MÓNICA

Rio de Janeiro

Congreso; 13th International Congresss of Immunology; 2007

IUIS-ALAI-SBI

We have shown that histamine (H) improves uptake of antigens as OVA and HRP by immature mice dendritic cells (DC). Here we analyzed whether histamine may be able to modulate MCH class-I restricted presentation by DC. DC were obtained from C57BL/6 bone marrow progenitors cultured with GM-CSF. They were treated with H (1 M) for 30 min at 37oC. Then, we evaluated the cross-presentation of OVA epitope by a colorimetric assay. Our results support that H may favor cross-presentation by Dc (media  SE, Ct: 0.53  0.05; H: 1.100  0.09, *p0.05 n=4) through H3R/H4R, probably enabling the activation of allergen-specific T CD8+. As these cells appear to play an important role in the development of allergic responses in the airway, we studied the H3R/H4R antagonist (Thioperamide: Thi) effect on an allergic model in mice. The allergized mice were vaccinated with DC pre-treated with H (1 M for 30 min at 37oC) or DC pre-treated with Thi and week later the phenotype of lung cells population was evaluated by flow cytometry. The results demonstrate that, while in allergic mice vaccinated with DC pre-treated with H, the lung CD8+ population was increased respect of the controls, in mice vaccinated with DC pre-treated with Thi, the number of these cells returned to normal values.