Mina, an Il4 repressor, controls T helper type 2 bias.

Area of Science:

• Immunology
• Molecular Biology
• Genetics

Background:

• T helper type 2 (T(H)2) bias, a predisposition for CD4(+) T cells to become IL-4-secreting T(H)2 cells, influences susceptibility to infectious, autoimmune, and allergic diseases.
• This bias is linked to initial IL-4 secretion, which activates a positive feedback loop involving the IL-4 receptor, STAT6, and GATA-3, promoting T(H)2 development.

Purpose of the Study:

• To identify genetic determinants of T(H)2 bias.
• To elucidate the regulatory mechanisms controlling T(H)2 cell differentiation and IL-4 expression.

Main Methods:

• Identification of Mina, a JmjC protein family member, as a genetic factor.
• Investigation of Mina's interaction with the Il4 promoter.
• Analysis of Il4 expression in transgenic mice overexpressing Mina and in primary CD4(+) T cells with Mina knockdown.

Main Results:

• Mina was identified as a genetic determinant of T(H)2 bias.
• Mina specifically binds to and represses the Il4 promoter.
• Overexpression of Mina in mice reduced Il4 expression, while knockdown in T cells led to Il4 derepression.

Conclusions:

• Mina plays a crucial role in regulating T(H)2 cell differentiation by controlling Il4 expression.
• These findings provide mechanistic insight into the Il4-regulatory pathway and genetic variations affecting T(H)2 bias.