Eosinophils in innate immunity: an evolving story

Abstract

Eosinophils are innate immune leukocytes found in relatively low numbers within the blood. Terminal effector functions of eosinophils, deriving from their capacity to release their content of tissue-destructive cationic proteins, have historically been considered primary effector mechanisms against specific parasites, and are likewise implicated in tissue damage accompanying allergic responses such as asthma. However, the past decade has seen dramatic advancements in the field of eosinophil immunobiology, revealing eosinophils to also be key participants in many other facets of innate immunity, from bridging innate and adaptive immune responses to orchestrating tissue remodeling events. Here, we review the multifaceted functions of eosinophils in innate immunity that are currently known, and discuss new avenues in this evolving story.

Contribution of myeloid cell subsets to liver fibrosis in parasite infection

“…In contrast to skin macrophages, skin eosinophils did not exert a suppressive activity on the capacity of DCs to trigger T cell proliferation. They can exert immune regulatory roles in the fibrotic process by driving M2 macrophage activation in the skin and/or the liver, being a predominant source of IL-4, IL-13 and Relma, and as mediators of tissue injury or tissue remodelling and debris clearance following tissue injury [65,67,78,89,101,[120][121][122]. However, despite constituting the major cell population in hepatic granulomas (∼50%), the function of eosinophils during infection largely remains elusive.…”

Eosinophilia in Children with Single and Mixed Soil Transmitted Helminthiasis

“…This happens also in hosts immunologically naïve to the invading parasite, a fact suggesting that eosinophils play a role in innate defence against this type of pathogen [1]. This rapid and non-spesific eosinophilic response might be a barrier limiting mechanism active against the invasion of many tissue-dwelling helminthes.…”

“…Eosinophils can cause tissue damage through a number of different mechanism, including direct cytotoxicity, physical damage caused by tissue infiltration (spaceoccupying) and thromboembolic phenomena cause by eosinophil-induced hypercoagulability. However, it is the release of eosinophil granule proteins and other cytotoxic substances that has been best correlated with helminth-induced tissue damage [1], [2]. Blood eosinophilia usually is defined as eosinophilia in excess of 500 cells/µl of blood.…”

“…Blood eosinophilia usually is defined as eosinophilia in excess of 500 cells/µl of blood. Other cut-offs for blood eosinophilia have been proposed to adjust for improved sensitivity and specificity in certain epidemiological and diagnostic settings, such as 600 eosinophils/ µl in tropical areas with a high prevalence of parasitic infections, or 450/ µl in travellers returning from those areas [1], [5]. Helminth infection can cause serious acute and chronic disease, but the majority of individuals with intestinal helminth infections are asymptomatic.…”

Patogênese da endomiocardiofibrose: perfil imunológico e análise proteômica de tecido cardíaco

“…(15,16) ambiental associada a doença, e a participação de parasitoses na patogênese explicaria a restrição da EMF nas regiões tropicais e subtropicais. (7,10,13,14) Rashwan e cols, (26) em 1995 descreveram alguns casos de EMF em pacientes com histórico de infestação por Schistosoma mansoni.…”