Helminth parasites are the most common infectious agents of humans in developing countries. Helminths typically induce a type 2 immune response which is characterized by a complex interplay of innate and adaptive immune cells. Cells of the myeloid cell lineage such as granulocytes (neutrophils, eosinophils, basophils, and mast cells), macrophages, and monocytes as well as dendritic cells carry out essential functions in all aspects of host immune responses against helminth infections. This includes protective responses, but also wound repair, metabolism, and restoration of homeostasis.
Eosinophils are the hallmark cell type of helminth infections. They show rapid migration to the site of infection, mediating degranulation of toxic proteins with marked anthelminthic activity, tissue remodeling, and debris clearance during wound healing. Eosinophils, along with other potent sources of granules and IL-4 such as basophils and mast cells, are often at the center of a type 2 response and mediate resistance against helminths in various tissues.
Two other myeloid cell types that are rapidly recruited to the site of infection are neutrophils and monocytes. Both of these cells are usually associated with bacterial infections, but studies have expanded their roles demonstrating key functions during helminth infections. While neutrophils use granule proteins and neutrophil extracellular trap (NET) formation, monocytes can differentiate into macrophages that can become alternatively activated during helminth infection, contributing to wound healing, immune regulation and mediate host resistance. All of these innate cells, together with dendritic cells, promote the adaptive arm of the type 2 response, ultimately resulting in expulsion of the helminths.
On the flip side, excessive activity of myeloid cells can result in pathological symptoms and tissue damage. How this balance is maintained between protection and pathology is one of the key aspects of type 2 immunity. Thus, immune modulation of these cell types by helminths not only contributes to parasite survival but also prevents excessive damage and pathology development.
This special issue of “Frontiers in Immunology” aims to collect research articles and reviews covering the latest findings in helminth immunology with a special focus on myeloid cells. The goal of this special issue is to update the scientific community with the latest immunological research on myeloid cell biology during helminth infections. While these cells have been studied extensively in the past, cutting-edge technology, transcriptomic and proteomic approaches defined new roles for these old players.
Topics covered by the collection:
- Myeloid cell effector mechanisms against helminths.
- Immunomodulation by helminths on myeloid cells.
- Immunopathology induced by myeloid cells during helminth infection.
Summary of article types:
Original Research, Reviews, Mini-Reviews, Methods and Perspectives articles
Topic Editor Paul Giacomin is theDirector and co-Founder of Macrobiome Therapeutics. The other Topic Editors declare no competing interests with regard to the Research Topic subject.
Helminth parasites are the most common infectious agents of humans in developing countries. Helminths typically induce a type 2 immune response which is characterized by a complex interplay of innate and adaptive immune cells. Cells of the myeloid cell lineage such as granulocytes (neutrophils, eosinophils, basophils, and mast cells), macrophages, and monocytes as well as dendritic cells carry out essential functions in all aspects of host immune responses against helminth infections. This includes protective responses, but also wound repair, metabolism, and restoration of homeostasis.
Eosinophils are the hallmark cell type of helminth infections. They show rapid migration to the site of infection, mediating degranulation of toxic proteins with marked anthelminthic activity, tissue remodeling, and debris clearance during wound healing. Eosinophils, along with other potent sources of granules and IL-4 such as basophils and mast cells, are often at the center of a type 2 response and mediate resistance against helminths in various tissues.
Two other myeloid cell types that are rapidly recruited to the site of infection are neutrophils and monocytes. Both of these cells are usually associated with bacterial infections, but studies have expanded their roles demonstrating key functions during helminth infections. While neutrophils use granule proteins and neutrophil extracellular trap (NET) formation, monocytes can differentiate into macrophages that can become alternatively activated during helminth infection, contributing to wound healing, immune regulation and mediate host resistance. All of these innate cells, together with dendritic cells, promote the adaptive arm of the type 2 response, ultimately resulting in expulsion of the helminths.
On the flip side, excessive activity of myeloid cells can result in pathological symptoms and tissue damage. How this balance is maintained between protection and pathology is one of the key aspects of type 2 immunity. Thus, immune modulation of these cell types by helminths not only contributes to parasite survival but also prevents excessive damage and pathology development.
This special issue of “Frontiers in Immunology” aims to collect research articles and reviews covering the latest findings in helminth immunology with a special focus on myeloid cells. The goal of this special issue is to update the scientific community with the latest immunological research on myeloid cell biology during helminth infections. While these cells have been studied extensively in the past, cutting-edge technology, transcriptomic and proteomic approaches defined new roles for these old players.
Topics covered by the collection:
- Myeloid cell effector mechanisms against helminths.
- Immunomodulation by helminths on myeloid cells.
- Immunopathology induced by myeloid cells during helminth infection.
Summary of article types:
Original Research, Reviews, Mini-Reviews, Methods and Perspectives articles
Topic Editor Paul Giacomin is theDirector and co-Founder of Macrobiome Therapeutics. The other Topic Editors declare no competing interests with regard to the Research Topic subject.