Eosinophils are dispensable for the regulation of IgA and Th17 responses in Giardia muris infection

Abstract

The small intestinal protozoan parasite Giardia lamblia is a major cause of food-and water-borne diarrhoeal disease worldwide. 1,2 Mice deficient in B cells, IgA, the polymeric immunoglobulin receptor A (pIgR) or IL-17A fail to control infections with G lamblia or the murine species G muris, emphasizing the importance of humoral immunity and Th17 cells for the control of giardiasis. 2-7 In line with those findings, we have previously observed differential Th17 activity, IgA production and regulatory T-cell responses associated with differences in susceptibility of inbred mouse lines towards G muris infection. 8 Over the last decade, eosinophils were shown to regulate both IgA production and Th17 activity at steady state and during infection (reviewed in 9,10). Eosinophils typically expand during helminth infection and may trap and damage migrating larvae of parasitic

Antibiotic-inducedMalasseziaspp. expansion in infants promotes early-life immune dysregulation and airway inflammation in mice

“…4, S10). This is in agreement with a previous publication showing eosinophils are dispensable for intestinal adaptive responses in a Giardia muris infection model 116 , and that immune responses to intestinal fungal colonizers increase Th17 induction in the airways 13,62,117 .…”

Evaluation of immune response and haematological parameters in infected male albino rats by giardiasis

“…In a previous study that determined the relative cyst shedding and trophozoite loads in the small intestine of murine, trophozoite counts are deemed to be an accurate indicator of parasite load 16 . The findings of the present study indicated that the number of trophozoites in the intestine of animals infected with G. lamblia was dramatically increased after 7–21 days of infection.…”

“…Studies have found that the numbers of eosinophils and granulocytes involved in host defence against parasites are increased 15 . Eosinophilia is a common finding in the bloodstream and various tissues during helminth and protozoan parasite infections as eosinophils are involved in direct parasite killing, immunomodulation and possibly wound healing 16 …”

“…15 Eosinophilia is a common finding in the bloodstream and various tissues during helminth and protozoan parasite infections as eosinophils are involved in direct parasite killing, immunomodulation and possibly wound healing. 16 In human and animal models, antibodies, especially secretory IgA, contribute to protective immunity. 11 IgA and IgG were found in mucosal secretions of humans and mice infected with Giardia, 17 and their levels increased 2 weeks after the infection.…”

Living without eosinophils: evidence from mouse and man

“…Multiple studies have assessed responses of ΔdblGATA and PHIL mice to viruses, protozoa and bacteria ( table 2 ). Results for viral and protozoan pathogens have generally shown no differences between eosinophil-depleted mice and wild-type controls [ 69 – 71 ]. Regarding the effects of eosinophil depletion on bacterial colonisation, differences have been reported in gastrointestinal microbiota composition of eosinophil-deficient mice compared with wild-type controls [ 12 – 14 ].…”