Invited Lecture: Role of Membrane Receptors in the Release of T Helper 1 and 2 Cytokines by Eosinophils

Macrophages – Balancing Tolerance and Immunity

“…In the absence of proinflammatory reactions, eosinophils in peripheral tissues should therefore adopt an antiinflammatory phenotype, secreting IL-10. Indeed it may be conjectured that a combination of macrophages and eosinophils could mediate IgE-dependent cyotoxicity to helminth parasites, through upregulation of high affinity IgE receptors [359], at the same time releasing IL-10 but not NO, thus avoiding proinflammatory damage to the surrounding tissues [359][360][361]. This would be an example of innate tolerance driving adaptive (IgE-mediated) immunity, rather than the usual adaptive tolerance, and highlights the important distinction between inflammation and immunity, processes that are normally but not necessarily linked.…”

Apoptotic eosinophils express IL-2R chains α and β and co-stimulatory molecules CD28 and CD86

“…The expression of the IL-2 receptor chain a (CD25) has been observed on eosinophils from hypereosinophilic patients and patients with eosinophilia caused by graft versus host disease, eosinophils cultured in the presence of IL-3 and GM-CSF or patients receiving IL-2 treatment. [3][4][5][6][7]27 The IL-2 receptor consists of three chains. Whether the a-, b-and gchains are all required for signalling in eosinophils is not known, but at least the a-and b-chains are required in lymphocytes.…”

Human eosinophils modulate peripheral blood mononuclear cell response to Schistosoma mansoni adult worm antigen in vitro

“…Furthermore, evidence of the ability of eosinophils to regulate T-cell function has been reviewed (15,19), highlighting the role of eosinophils in both innate and adaptive immunity. Eosinophils express both Th-1 (IFN-c, IL-2) and Th-2 (IL-4, IL-5, IL-13) cytokines (20)(21)(22). In mice infected with Schistosoma mansoni, eosinophils have been associated with Th-2 polarization by IL-4 production (23) and can be a dominant source of Th-2 type cytokines (24).…”