How do basophils contribute to Th2 cell differentiation and allergic responses?

Area of Science:

• Immunology
• Cell Biology

Background:

• Basophils and mast cells share similarities, leading to basophils being historically underestimated.
• Recent advancements have revealed unique functions of basophils in immune responses.

Purpose of the Study:

• To review the distinct roles of basophils in immunity, focusing on antigen presentation and allergic inflammation.
• To highlight the function of basophils in driving T-helper 2 (Th2) cell differentiation.
• To discuss basophil-specific molecules involved in allergic responses.

Main Methods:

• Utilizing basophil-depleting antibodies and genetically engineered mice.
• Investigating basophil antigen-presenting cell (APC) function via trogocytosis of MHC-II complexes.
• Analyzing the role of mouse mast cell proteases (mMCPs) 8 and 11 in vitro and in vivo.

Main Results:

• Basophils acquire and present peptide-MHC-II complexes, promoting naive CD4 T cell differentiation into Th2 cells.
• Basophils produce IL-4, further supporting Th2 cell differentiation.
• Basophil-specific proteases, mMCP-8 and mMCP-11, induce leukocyte migration and contribute to allergic inflammation.

Conclusions:

• Basophils are crucial immune cells with functions distinct from mast cells.
• Basophils act as potent antigen-presenting cells, driving Th2-mediated immune responses.
• Basophil-derived proteases play a significant role in orchestrating allergic inflammation.