biostudies-literatureSasse CDeutsche ForschungsgemeinschaftInterdisciplinary Center for Clinical Research (IZKF), Universitätsklinikum ErlangenFederal Ministry of Education and Research828https://www.ebi.ac.uk/biostudies/studies/S-EPMC9331382biostudies-literatureUnknown11(8)Interleukin (IL)-4 plays a central role in the initiation of a type 2 T helper cell (Th2) response, which leads to non-healing and progressive infections with the protozoan parasite <i>Leishmania</i> (<i>L.</i>) <i>major</i>. Here, we tested the hypothesis that type 2 innate lymphoid cells (ILC2), which promote the development of Th2 cells, form an important source of IL-4 early after intradermal or subcutaneous <i>L. major</i> infection. Lineage-marker negative CD90.2⁺CD127⁺PD1^- ILC2 were readily detectable in the ear or foot skin, but hardly in the draining lymph nodes of both naïve and <i>L. major</i>-infected self-healing C57BL/6 and non-healing BALB/c mice and made up approximately 20% to 30% of all CD45⁺SiglecF^- cells. Dermal ILCPathogens (Basel, Switzerland)Eosinophils, but Not Type 2 Innate Lymphoid Cells, Are the Predominant Source of Interleukin 4 during the Innate Phase of <i>Leishmania major</i> Infection.PMC9331382CRC1181 (project C4); RTG2740 (project A6 and B2); SPP1937 (BO996/5-1 and 5-2;SCHL615/1-1 and 1-2)Project A87031L0126Schleicher UBogdan CDebus AObermeyer SSasse CBarinberg DfalseEosinophils, but Not Type 2 Innate Lymphoid Cells, Are the Predominant Source of Interleukin 4 during the Innate Phase of <i>Leishmania major</i> Infection.Interleukin (IL)-4 plays a central role in the initiation of a type 2 T helper cell (Th2) response, which leads to non-healing and progressive infections with the protozoan parasite <i>Leishmania</i> (<i>L.</i>) <i>major</i>. Here, we tested the hypothesis that type 2 innate lymphoid cells (ILC2), which promote the development of Th2 cells, form an important source of IL-4 early after intradermal or subcutaneous <i>L. major</i> infection. Lineage-marker negative CD90.2⁺CD127⁺PD1^- ILC2 were readily detectable in the ear or foot skin, but hardly in the draining lymph nodes of both naïve and <i>L. major</i>-infected self-healing C57BL/6 and non-healing BALB/c mice and made up approximately 20% to 30% of all CD45⁺SiglecF^- cells. Dermal ILC2022-01-01T00:00:00Z2022 Jul2025-05-18T13:32:32.153Z2025-05-18T13:32:32.153ZS-EPMC93313823589405110.3390/pathogens11080828