Mechanisms of molluscan host resistance and of parasite strategies for survival

Bayne, Christopher J.; Hahn, Ulrike; Bender, Randall C.

doi:10.1017/s0031182001008137

Cited by 109 publications

(86 citation statements)

References 47 publications

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“…These data support our results in regard to the rise in the hemocyte count during the first hours after miracidia penetration, as well as to the subsequent decline in the 22,23,24 circulating hemocyte numbers .…”

Section: Resultssupporting

confidence: 91%

Hemocyte production in Biomphalaria glabrata snails after exposure to different Schistosoma mansoni infection protocols

Santos¹,

Santos²,

Rodrigues³

2011

Rev Pan-Amaz Saude

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The objective of this work was to determine the profile of the cellular defense system during mansonic infection. Specifically, this study assessed the number of hemocytes that were produced and released into the hemolymph in response to the parasitic infection. The quantification of the Biomphalaria glabrata hemocytes was performed on groups of snails at 1, 5, 10, 15, 20 and 30 days post-infection that had been individually infected with 5, 10, 15 or 30 Schistosoma mansoni miracidia. The results revealed that B. glabrata possesses a cellular defense mechanism that is characterized by the release of hemocytes into the hemolymph. The maximum peak of cellular production occurred 24 hours after infection, and there was a significant reduction in the hemocyte concentration over the following 10 days. However, at 15 days post-infection, there was a second increase in the cellular hemocyte production, although this was not as strong as the primary peak. At 30 days post-infection, there was another moderate rise in the cellular hemocyte production. Based on this cellular response profile, the defense system of the snail appears to be effective immediately following infection, but the response does not ensure the destruction of all parasites during the course of the infection.

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Section: Resultssupporting

confidence: 91%

Hemocyte production in Biomphalaria glabrata snails after exposure to different Schistosoma mansoni infection protocols

Santos¹,

Santos²,

Rodrigues³

2011

Rev Pan-Amaz Saude

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“…glabrata H 2 O 2 production appears to be a critical component of its immune response against S. mansoni larval stages [31]. The putative regulation of such immune responses can be estimated through in vitro PMA-and BSA-gal-stimulation of B. glabrata hemocytes.…”

Section: Discussionmentioning

confidence: 99%

Regulation of hydrogen peroxide release in circulating hemocytes of the planorbid snail Biomphalaria glabrata

Humphries

Yoshino

2008

Developmental & Comparative Immunology

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Biomphalaria spp. serve as obligate intermediate hosts for the human blood fluke Schistosoma mansoni. Following S. mansoni penetration of Biomphalaria glabrata, hemocytes of resistant snails migrate towards the parasite, encasing the larva in a multicellular capsule resulting in its destruction via a cytotoxic reaction. Recent studies have revealed the importance of hydrogen peroxide and nitric oxide (H 2 O 2 , NO) in parasite killing [1,2]. It is assumed H 2 O 2 and NO production is tightly regulated although the specific molecules involved remain largely unknown. Consequently, the potential role of cell signaling pathways in B. glabrata hemocyte H 2 O 2 production was investigated by evaluating the effects of specific inhibitors of selected signaling proteins. Results suggest that both ERK and p38 MAPKs are involved in the regulation of B. glabrata H 2 O 2 release in response to stimulation by PMA and galactose-conjugated BSA. However, the involvement of the signaling proteins PKC, PI 3 kinase and PLA 2 differs between PMA-and BSA-gal-induced H 2 O 2 production.

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“…Because of the diverse roles played by galectins in regulating key aspects of the innate immune system of vertebrates (Vasta et al, 2004a;Rabinovitch et al, 2002), such as phagocytosis (Sano et al, 2003), pattern-recognition of parasite antigens (Young and Meeusen, 2004;Van der Berg et al, 2004), and especially regulation of T-cell activation and apoptosis by gal-4 and gal-9 (Ilarregui et al, 2005;Dai et al, 2005), the finding of BgGal expression in circulating phagocytic cells of B. glabrata was of particular interest. Hemocytes are the primary line of immune defense against invading microbial and parasitic infections in molluscs and, upon pathogen recognition, are capable of eliminating infections through phagocytic or encapsulation responses (Bayne et al, 2001;Labrenche et al, 2006). In resistant strains of B. glabrata, infection by early larval stages of the human blood fluke Schistosoma mansoni elicits hemocytic encapsulation reactions (Loker et al, 1982), although the molecules responsible for parasite recognition (pattern recognition receptors or PRRs) and hemocyte adherence are yet unknown.…”

Section: Nih-pa Author Manuscriptmentioning

confidence: 99%

Molecular and functional characterization of a tandem-repeat galectin from the freshwater snail Biomphalaria glabrata, intermediate host of the human blood fluke Schistosoma mansoni

Yoshino

Dinguirard

Kunert

et al. 2008

Gene

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In the present study, a tandem-repeat type galectin was characterized from an embryonic cell line (Bge) and circulating hemocytes of the snail Biomphalaria glabrata, intermediate host of the human blood fluke Schistosoma mansoni. The predicted B. glabrata galectin (BgGal) protein of 32 kDa possessed 2 carbohydrate recognition domains, each displaying 6 of 8 conserved amino acids involved in galactoside-binding activity. A recombinant BgGal (rBgGal) demonstrated hemagglutinating activity against rabbit erythrocytes, which was specifically inhibited by galactosecontaining sugars (lacNAc/lac > galNAc/gal). Although native galectin was immunolocalized in the cytoplasm of Bge cells and the plasma membrane of a subset of snail hemocytes (60%), it was not detected in cell-free plasma by Western blot analysis. The findings that rBgGal selectively recognizes the schistosome-related sugar, lacNAc, and strongly binds to hemocytes and the tegument of S. mansoni sporocysts in a sugar-inhibitable fashion suggest that hemocyte-bound galectin may be serving as pattern recognition receptor for this, or other pathogens possessing appropriate sugar ligands. Based on molecular and functional features, BgGal represents an authentic galectin, the first to be fully characterized in the medically-important molluscan Class Gastropoda.

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Mechanisms of molluscan host resistance and of parasite strategies for survival

Cited by 109 publications

References 47 publications

Hemocyte production in Biomphalaria glabrata snails after exposure to different Schistosoma mansoni infection protocols

Hemocyte production in Biomphalaria glabrata snails after exposure to different Schistosoma mansoni infection protocols

Regulation of hydrogen peroxide release in circulating hemocytes of the planorbid snail Biomphalaria glabrata

Molecular and functional characterization of a tandem-repeat galectin from the freshwater snail Biomphalaria glabrata, intermediate host of the human blood fluke Schistosoma mansoni

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