IL-33 Upregulates Cysteinyl Leukotriene Receptor Type 1 Expression in Human Peripheral Blood CD4⁺ T Lymphocytes

Area of Science:

• Immunology
• Allergy and Asthma Research

Background:

• Interleukin-33 (IL-33) and cysteinyl leukotrienes (cysLTs) are crucial in asthma pathogenesis.
• The interaction between IL-33 and cysLTs in asthma is not well understood.

Purpose of the Study:

• To investigate how IL-33 regulates the expression of cysLT receptors (CysLT1 and CysLT2) in human peripheral blood lymphocytes (PBLs).

Main Methods:

• Human PBLs were treated with IL-33 to assess CysLT1 and CysLT2 expression.
• Protein and mRNA levels of CysLT1 were analyzed.
• Functional assays measured LTD4-induced calcium mobilization and CD4+ T cell migration.
• Naive CD4+ T lymphocytes were examined for ST2L expression and response to IL-33.

Main Results:

• IL-33 significantly increased CysLT1 protein expression in PBLs in a dose- and time-dependent manner, but not CysLT2.
• This upregulation enhanced LTD4-induced calcium influx and CD4+ T cell migration.
• Naive CD4+ T cells express ST2L and respond to IL-33 independently of antigen stimulation.

Conclusions:

• The IL-33/ST2L pathway modulates CysLT1 expression at the protein level in human PBLs.
• IL-33 influences naive CD4+ T cell trafficking, suggesting a novel mechanism of action for IL-33.
• These findings highlight IL-33 as a potential therapeutic target for asthma.