Immunology of Giardiasis

denHollander, Neal; Riley, Doone; Befus, Dean

doi:10.1016/0169-4758(88)90186-x

Cited by 34 publications

(26 citation statements)

References 57 publications

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“…This issue has become more complex in recent years with the discovery that IELs expressing the ºä for the T-cell receptor (TCR) are also influenced by, and possibly involved in, these pathological processes. den Hollander et al [21] also suggest that IELs have a potential protective role during giardiasis, as well as a simultaneous pathogenic effect.…”

Section: Discussionmentioning

confidence: 99%

Influence of bacteria from the duodenal microbiota of patients with symptomatic giardiasis on the pathogenicity of Giardia duodenalis in gnotoxenic mice

Torres¹,

Uetanabaro

Costa³

et al. 2000

Journal of Medical Microbiology

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Recent studies have shown that the intestinal microbiota is essential for the pathogenicity but not for the multiplication of Giardia duodenalis in the intestinal lumen. The microbial components responsible for this phenomenon are not known. Twenty-eight facultative and three strictly anaerobic micro-organisms were isolated from the dominant duodenal microbiota of five patients with symptomatic giardiasis. The bacterial combinations from each patient were associated with groups (GN) of germ-free mice. Five days after the association, when their faecal populations ranged from 10 7 to 10 9 cfu=g, all groups were inoculated intragastrically with 10 5 viable trophozoites of G. duodenalis strain BT6. Two groups of germ-free (GF) and conventional (CV1) mice were also infected. Gnotobiotic animals were killed 10 days after infection and GF and CV1 animals were killed 10, 20 and 30 days after infection. More marked pathological alterations were detected in CV1 mice when compared with GF animals. Gnotobiotic animals showed intermediate pathological alterations between CV1 and GF mice. The CV1 and GF groups became infected by day 3 and faecal cyst levels were similar in both groups throughout the experiment. Total and G. duodenalis-specific IgA levels in the intestinal fluid and G. duodenalis-specific IgM and IgG levels in the serum increased during the infection and were higher in CV1 animals at all times tested when compared with GF mice. The present results confirm the stimulatory activity of the intestinal microbiota on the pathogenicity of G. duodenalis, and some combinations of microbial components of the dominant duodenal ecosystem from patients with symptomatic giardiasis can partially develop this function. However, none of these combinations was able to stimulate the protozoan pathogenicity in the same manner as the entire intestinal microbiota.

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Section: Discussionmentioning

confidence: 99%

Influence of bacteria from the duodenal microbiota of patients with symptomatic giardiasis on the pathogenicity of Giardia duodenalis in gnotoxenic mice

Torres¹,

Uetanabaro

Costa³

et al. 2000

Journal of Medical Microbiology

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“…In addition to some similarity among the strains, differences could be detected mainly in membrane-bound protein fractions. According to DEN HOLLANDER et al 4 , differences among Giardia isolates can be most pronounced in the membrane fractions, although differences may exist in other fractions as well.…”

Section: Discussionmentioning

confidence: 99%

“…So, we did not analyse the surface proteins but those associated with all membranes of the trophozoites. Therefore, according to DEN HOLLANDER et al 4 , as Giardia spp have few internal demonstrated membrane-bound organelles, the membrane differences among isolates may involve polypeptides of plasma membrane.…”

Section: Discussionmentioning

confidence: 99%

Analysis of proteins from membrane and soluble fractions of Giardia duodenalis trophozoites of two Brazilian axenic strains

Guimarães

Sogayar

Franco

2002

Rev. Inst. Med. trop. S. Paulo

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SUMMARYIn the present study, we have analyzed by sodium docecyl sulphate -polyacrilamide gel electrophoresis (SDS-PAGE), immunoblotting and Concanavalin A blotting (Con A blotting) proteins of membrane fractions and soluble fractions obtained from Giardia duodenalis trophozoites of two axenic strains isolated in Brazil from a symptomatic (BTU-11) and an asymptomatic patient (BTU-10), as compared to the reference strain Portland 1. Both Brazilian strains showed a complex and homogeneous electrophoretic pattern of proteins, but some differences could be observed. Several glycoproteins were detected, particularly the proteins of 81, 72, 59 kDa and the protein of 62 kDa in the membrane proteins and cytosol, respectively. Many antigenic components were revealed by anti-Giardia rabbit IgG antibodies in the immunoblotting analysis. Among these components, the membrane protein of 32 kDa and the cytosol protein of 30 kDa could be related to giardin, as previously demonstrated.

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“…Although cer tain strains do appear to be more effective than others at establishing infection [31], no markers for virulence have been identified to date. The most likely pathophysiological mechanism, however, is an immunopathological process involving intraepithelial lympho cytes directed against Giardia antigens, to gether with cytokines and other cells of the inflammatory immune response [32], possi bly in a manner similar to the response to wheat gliadin seen in coeliac disease.…”

Section: Pathogenesis Of Giardiasismentioning

confidence: 99%

“…Recent studies have revealed that Giardia iso lates undergo antigenic variation in vivo with the loss of the major surface antigens present before infection [33], The clinical significance of these findings with respect to chronic or repeated infections has yet to be determined, but will be vital in the development of effec tive vaccines. Host factors are also important, and an increased incidence of giardiasis has been associated with certain HLA markers [34] , The immune events associated with giar diasis are as yet incompletely understood, but arc usefully reviewed by den Hollander et al [32],…”

Section: Host Immune Response To Infectionmentioning

confidence: 99%

<i>Giardia lamblia </i>as an Intestinal Pathogen

Lewis

Freedman²

1992

Dig Dis

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Giardia lamblia are protozoan parasites which cause human intestinal disease. The life cycle has a multiplying intraduodenal trophozoite and an excreted cyst. Infection occurs after cyst ingestion from faecally contaminated water or by direct faecal-oral transmission in situations of poor sanitary standards, but the zoonotic nature of giardiasis is debated. The pathophysiology may arise from enzyme or active transport deficiencies, synergy with intestinal bacteria or an immunopathological process. Diagnosis is made by microscopic identification of cysts or trophozoites in small bowel samples or faeces. Symptoms are acute with diarrhoea (without blood), abdominal cramps, bloating and flatulence. The treatment of choice is either metronidazole or tinidazole. No vaccine or drug prophylaxis exists, and measures to avoid cyst ingestion should be undertaken.

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Immunology of Giardiasis

Cited by 34 publications

References 57 publications

Influence of bacteria from the duodenal microbiota of patients with symptomatic giardiasis on the pathogenicity of Giardia duodenalis in gnotoxenic mice

Influence of bacteria from the duodenal microbiota of patients with symptomatic giardiasis on the pathogenicity of Giardia duodenalis in gnotoxenic mice

Analysis of proteins from membrane and soluble fractions of Giardia duodenalis trophozoites of two Brazilian axenic strains

<i>Giardia lamblia </i>as an Intestinal Pathogen

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