Secretory Glands in Cercaria of the Neuropathogenic Schistosome Trichobilharzia Regenti - Ultrastructural Characterization, 3-D Modelling, Volume and PH Estimations

Overview

Journal Parasit Vectors

Publisher Biomed Central

Specialties Parasitology
Tropical Medicine

Date 2011 Aug 23

PMID 21854564

Citations 11

Authors

Anna Ligasova

Jana Bulantova

Ondrej Sebesta

Martin Kasny

Karel Koberna

Libor Mikes

Affiliations

Soon will be listed here.

Abstract

Background: Cercariae of schistosomes employ bioactive molecules for penetration into their hosts. These are released from specialized unicellular glands upon stimuli from host skin. The glands were previously well-described in the human pathogen Schistosoma mansoni. As bird schistosomes can also penetrate human skin and cause cercarial dermatitis, our aim was to characterize the architecture and ultrastructure of glands in the neurotropic bird schistosome Trichobilharzia regenti and compare it with S. mansoni. In the context of different histolytic enzymes used by these two species, we focused also on the estimations of gland volumes and pH in T. regenti.

Results: The architecture and 3-D models of two types of acetabular penetration glands, their ducts and of the head gland are shown here. We characterized secretory vesicles in all three gland types by means of TEM and confirmed accuracy of the models obtained by confocal microscopy. The results of two independent approaches showed that the glands occupy ca. one third of cercarial body volume (postacetabular glands ca. 15%, circumacetabular 12% and head gland 6%). The inner environment within the two types of acetabular glands differed significantly as evidenced by dissimilar ability to bind fluorescent markers and by pH value which was higher in circumacetabular (7.44) than in postacetabular (7.08) glands.

Conclusions: As far as we know, this is the first presentation of a 3-D model of cercarial glands and the first exact estimation of the volumes of the three gland types in schistosomes. Our comparisons between T. regenti and S. mansoni implied that the architecture and ultrastructure of the glands is most likely conserved within the family. Only minor variations were found between the two species. It seems that the differences in molecular composition have no effect on general appearance of the secretory cells in TEM. Fluorescent markers employed in this study, distinguishing between secretory vesicles and gland types, can be useful in further studies of mechanisms used by cercariae for host invasion. Results of the first attempts to estimate pH within schistosome glands may help further understanding of regulation of enzymatic activities present within the glands.

Citing Articles

A cercarial invadolysin interferes with the host immune response and facilitates infection establishment of Schistosoma mansoni.

Hambrook J, Hanington P PLoS Pathog. 2023; 19(2):e1010884.

PMID: 36730464 PMC: 9928134. DOI: 10.1371/journal.ppat.1010884.

Molecular evidence for distinct modes of nutrient acquisition between visceral and neurotropic schistosomes of birds.

Leontovyc R, Young N, Korhonen P, Hall R, Bulantova J, Jerabkova V Sci Rep. 2019; 9(1):1347.

PMID: 30718911 PMC: 6362228. DOI: 10.1038/s41598-018-37669-2.

Cercarial dermatitis: a systematic follow-up study of human cases with implications for diagnostics.

Machacek T, Turjanicova L, Bulantova J, Hrdy J, Horak P, Mikes L Parasitol Res. 2018; 117(12):3881-3895.

PMID: 30302587 DOI: 10.1007/s00436-018-6095-0.

Changes in surface glycosylation and glycocalyx shedding in Trichobilharzia regenti (Schistosomatidae) during the transformation of cercaria to schistosomulum.

rimnacova J, Mikes L, Turjanicova L, Bulantova J, Horak P PLoS One. 2017; 12(3):e0173217.

PMID: 28296924 PMC: 5351870. DOI: 10.1371/journal.pone.0173217.

A next-generation microarray further reveals stage-enriched gene expression pattern in the blood fluke Schistosoma japonicum.

Cai P, Liu S, Piao X, Hou N, You H, McManus D Parasit Vectors. 2017; 10(1):19.

PMID: 28069074 PMC: 5223471. DOI: 10.1186/s13071-016-1947-x.

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