Nuocytes represent a new innate effector leukocyte that mediates type-2 immunity

Area of Science:

• Immunology
• Cell Biology
• Infectious Disease

Background:

• Innate immunity is the initial defense against pathogens and guides adaptive immunity.
• Type-2 immunity, involving interleukin-4 (IL-4), IL-5, and IL-13, combats helminths but causes allergic asthma.
• While T cells produce these cytokines in adaptive immunity, innate sources are not fully understood.

Purpose of the Study:

• To identify and characterize novel innate immune cells involved in type-2 immunity.
• To determine the role of these cells in interleukin-13 (IL-13) production during helminth infections.

Main Methods:

• Utilized novel Il13-eGFP reporter mice for cell identification.
• Investigated nuocyte expansion in response to IL-25 and IL-33.
• Assessed the impact of IL-25 and IL-33 signaling absence on immune response and worm expulsion.
• Performed adoptive transfer of nuocytes to evaluate their function.

Main Results:

• Identified and characterized a new innate immune cell named the nuocyte.
• Nuocytes expand in vivo upon stimulation with IL-25 and IL-33.
• Nuocytes are the predominant early source of IL-13 during Nippostrongylus brasiliensis infection.
• Absence of IL-25/IL-33 signaling impairs nuocyte expansion and worm expulsion, which can be rescued by wild-type nuocyte transfer.

Conclusions:

• Nuocytes are a critical innate effector cell population in type-2 immunity.
• These cells play a vital role in host defense against helminth parasites.
• Nuocytes are a key source of IL-13 in the innate immune response to type-2 stimuli.