Caffeic Acid Phenethyl Ester Inhibits Nuclear Factor-KappaB and Protein Kinase B Signalling Pathways and Induces Caspase-3 Expression in Primary Human CD4 T Cells
Clinical & Experimental Immunology, Volume 160 Issue 2, Pages 223 - 232
Caffeic acid phenethyl ester (CAPE), an active component in propolis, is known to have anti-tumour, anti-inflammatory and anti-oxidant properties. In this study, the effects of CAPE on the functions of primary human CD4(+) T cells were evaluated in vitro.
CAPE significantly suppressed interferon (IFN)-gamma and interleukin (IL)-5 production and proliferation of CD4(+) T cells stimulated by soluble anti-CD3 and anti-CD28 monoclonal antibodies in both healthy subjects and asthmatic patients.
CAPE inhibited nuclear factor (NF)-kappaB activation and protein kinase B (Akt) phosphorylation, but not p38 mitogen-activated protein kinase (MAPK) phosphorylation in T cells. CAPE also induced active caspase-3 expression in CD4(+) T cells; CCR4(+)CD4(+) T cells were more sensitive to CAPE induction than CXCR3(+)CD4(+) T cells.
Together, these results indicate that CAPE inhibits cytokine production and proliferation of T cells, which might be related to the NF-kappaB and Akt signalling pathways, and that CCR4(+)CD4(+) T cells are more sensitive to CAPE inhibition.
This study provides a new insight into the mechanisms of CAPE for immune regulation and a rationale for the use of propolis for the treatment of allergic disorders.