Histone acetyltransferease p300 modulates TIM4 expression in dendritic cells

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• T cell immunoglobulin mucin molecule-4 (TIM4) is key in initiating T helper 2 (Th2) polarization.
• The regulatory mechanisms governing TIM4 expression remain largely uncharacterized.

Purpose of the Study:

• To investigate the roles of p300 and signal transducer and activator transcription-6 (STAT6) in regulating TIM4 expression within dendritic cells (DCs).
• To elucidate the molecular pathways involved in TIM4 induction during allergic conditions.

Main Methods:

• A food allergy mouse model was established using ovalbumin and cholera toxin (CT).
• Chromatin immunoprecipitation assays were employed to assess chromatin modifications at the TIM4 and STAT6 promoters.
• TIM4 expression levels were quantified using real-time RT-PCR and Western blotting.

Main Results:

• Elevated levels of p300 and TIM4 were observed in intestinal DCs from allergic mice.
• Cholera toxin (CT) was found to induce TIM4 expression in DCs, a process involving p300.
• p300 interacts with the TIM4 promoter locus in DCs from allergic mice, and CT enhances p300 to modulate STAT6 levels.
• STAT6 was identified as a mediator of CT-induced TIM4 expression in DCs.

Conclusions:

• p300 and STAT6 are critical mediators of microbial product (CT)-induced TIM4 expression in dendritic cells.
• This pathway is significant in the context of allergic responses and Th2 polarization.