In vitro interactions between murine macrophages and Eimeria falciformis sporozoites

Bekhti, Khadija; Pery, P.

doi:10.1016/0923-2494(89)90023-0

Cited by 13 publications

(7 citation statements)

References 18 publications

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“…We hypothesized that the stronger early Th2 response might counteract effector mechanisms by e.g. macrophages, as mouse macrophages are able to internalize and kill E.f. sporozoites 30. H.p.b.…”

Section: Discussionmentioning

confidence: 99%

A matter of timing: Early, not chronic phase intestinal nematode infection restrains control of a concurrent enteric protozoan infection

et al. 2010

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Infections with parasitic worms are often long lasting and associated with modulated immune responses. We analyzed the influence of the nematode Heligmosomoides polygyrus bakeri dwelling in the small intestine on concurrent protozoan infection with Eimeria falciformis residing in the cecum. To dissect the effects of a nematode infection in the early versus chronic phase, we infected animals with E. falciformis 6 or 28 days post H. p. bakeri infection. Only a concurrent early nematode infection led to an increased replication of the protozoan parasite, whereas a chronic worm infection had no influence on the control of E. falciformis. Increased protozoan replication correlated with the reduced production of IFN-c, IL-12/23, CCL4, CXCL9 and CXCL10, reduced migration of T cells and increased expression of Foxp3 at the site of protozoan infection. This was accompanied by a stronger nematode-specific Th2 response in gut-draining LN. Protection of mice against challenge infections with the protozoan parasite was not altered. Hence, the detrimental effect of a nematode infection on the control of a concurrent protozoan infection is transient and occurs only in the narrow time window of the early phase of infection. Here, we analyzed the impact of a concurrent worm infection in the early phase versus chronic phase on the outcome of a concurrent enteric protozoan infection. We find that only early infections with H.p.b. result in an increased protozoan replication. The protozoan replication was not influenced in chronically worm-infected mice, despite signs of immunosuppression and sharply decreased IFN-g responses to Eimeria Ag in gut-draining mesenteric LN (mLN). Suppression of anti-Eimeria protective immunity during early nematode coinfection was found to be a result of a strong nematode-induced Th2 response and a reduced chemokine-mediated chemotaxis and migration of T cells to the site of Eimeria infection. Results Early phase nematode infection negatively affects the control of a primary Eimeria infectionTo test whether an infection with H.p.b. affects the course of infection with E. falciformis (E.f.) in a distinct part of the intestinal tract, mice were infected according to two protocols (Fig. 1A). E.f. was applied to mice in the early (histotrophic) phase (6 days post-H.p.b. infection, named eHpb/Ef) or chronic phase of adult worm infection (4 wk post-H.p.b. infection, named cHpb/Ef). Control mice were single infected only. Eimeria oocyst output was monitored on days 6-16 post-Eimeria infection.Interestingly, eHpb/Ef mice shed significantly more E.f. oocysts in comparison to controls infected with E.f. only (Fig. 1B and C) and had a significantly prolonged patency period (Fig. 1D). Conversely, an established chronic worm infection did not significantly alter the course of E.f. infection despite similar worm burdens (data not shown). Compared with Eimeria single-infected controls, cHpb/Ef mice had similar kinetics for oocyst output (Fig. 1B) as well as similar total numbers of shed oocysts ( Fig. 1C) and paten...

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Section: Discussionmentioning

confidence: 99%

A matter of timing: Early, not chronic phase intestinal nematode infection restrains control of a concurrent enteric protozoan infection

et al. 2010

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“…These results indicate that enhanced macrophage uptake of sporozoites in E. acervulina-immune chickens does not occur, although E. tenella-immune serum enhanced macrophage phagocytosis of sporozoites in vitro (75). Macrophages taken from both normal mice and mice immune to E. falciformis accumulated sporozoites in culture, but only immune macrophages became activated and digested the sporozoites in a complement-dependent mechanism (8). Macrophages produced a significant amount of TNF in vitro following stimulation with sporozoites and merozoites (118).…”

mentioning

confidence: 87%

“…However, the participation of these responses in protection against Eimeria parasites is unclear. Although in vitro studies showed that immune sera increase the phagocytosis of sporozoites and merozoites by macrophages in cultures (8,75), in vivo studies involving hormonal and chemical bursectomy (30,55) clearly indicated that antibodies play a minor role in protection against coccidiosis. It is possible that antibodies reduce the invasion of some (but not all) species of Eimeria or enhance the intraluminal destruction of sporozoites if parasites come into close contact with local antibodies before the parasites enter host cells.…”

Section: Host Immune Responsesmentioning

confidence: 99%

Avian gut-associated lymphoid tissues and intestinal immune responses to Eimeria parasites

Lillehoj¹,

Trout²

1996

Clin Microbiol Rev

288

128

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Coccidiosis, an intestinal infection caused by intracellular protozoan parasites belonging to several different species of Eimeria, seriously impairs the growth and feed utilization of livestock and poultry. Host immune responses to coccidial infection are complex. Animals infected with Eimeria spp. produce parasite-specific antibodies in both the circulation and mucosal secretions. However, it appears that antibody-mediated responses play a minor role in protection against coccidiosis. Furthermore, there is increasing evidence that cell-mediated immunity plays a major role in resistance to infection. T lymphocytes appear to respond to coccidial infection through both cytokine production and a direct cytotoxic attack on infected cells. The exact mechanisms by which T cells eliminate the parasites, however, remain unclear. Although limited information is available on the intestinal immune system of chickens, gut lymphoid tissues have evolved specialized features that reflect their role as the first line of defense at mucosal surfaces, including both immunoregulatory cells and effector cells. This review summarizes our current understanding of the avian intestinal immune system and mucosal immune responses to Eimeria spp., providing an overview of the complex cellular and molecular events involved in intestinal immune responses to enteric pathogens.

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“…In mammalian and avian coccidiosis, phagocytic cells were observed to internalize sporozoite and merozoite parasite stages (Long 1993). In vitro studies on interactions of Eimeria falciformis and murine peritonea1 macrophages demonstrated that lysis of internalized sporozoites occurred in immune macrophages and required both antibodies and complement (Bekhti & Pery 1989). In acute infections with C. carpedi, macrophages infiltrated affected gut areas and internalized deteriorated host cells and coccldia (Jendrysek et al 1994).…”

mentioning

confidence: 99%

Carp coccidiosis:activity of phagocytic cells from common carp infected with Goussia carpelli

Steinhagen¹,

Hespe²

1997

Dis. Aquat. Org.

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Pronephric phagocytes from common carp Cyprinus carpjo L. infected with the gut-dwelling coccidian Goussia carpelli showed enhanced phagocytic activity during the period of merogonic and gamogonic development of the parasite from Days 10 to 15 post exposure (PE) to the parasite. The respiratory burst activity was enhanced during excretion of oocysts at Days 15 to 25 PE. The addltion of parasite lysates to assays resulted in an increase of phagocyte activity in cells from carp infected with gamogonic and sporogonic stages of the parasite and from carp which, at Day 35 PE, had recovered from a G, carpel11 infection. The addition of immune serum sampled from fish at Days 5. 10, 15. 20, and 25 PE had no clear stimulatory effect on phagocyte activity This suggests an activation of pronephric phagocytes on infection with the parasite. In carp with gamogonic and sporogonic parasite stages, activated macrophages show an increased cytotoxic reactivity, and activated macrophages rather than non-activated resident macrophages can be enhanced by opsonization with parasite molecules.

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In vitro interactions between murine macrophages and Eimeria falciformis sporozoites

Cited by 13 publications

References 18 publications

A matter of timing: Early, not chronic phase intestinal nematode infection restrains control of a concurrent enteric protozoan infection

A matter of timing: Early, not chronic phase intestinal nematode infection restrains control of a concurrent enteric protozoan infection

Avian gut-associated lymphoid tissues and intestinal immune responses to Eimeria parasites

Carp coccidiosis:activity of phagocytic cells from common carp infected with Goussia carpelli

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