Cargando…

Immune reactivity and host modulatory roles of two novel Haemonchus contortus cathepsin B-like proteases

BACKGROUND: Haemonchus contortus is a blood-feeding, gastrointestinal nematode (GIN) that causes significant economic losses to the small ruminant industry worldwide. Despite extensive efforts, our understanding of the molecular mechanisms used by GIN to evade host immune responses is limited. Cathe...

Descripción completa

Detalles Bibliográficos
Autores principales: Bakshi, Mariam, Tuo, Wenbin, Aroian, Raffi V., Zarlenga, Dante
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8603344/
https://www.ncbi.nlm.nih.gov/pubmed/34798906
http://dx.doi.org/10.1186/s13071-021-05010-y
_version_ 1784601750967156736
author Bakshi, Mariam
Tuo, Wenbin
Aroian, Raffi V.
Zarlenga, Dante
author_facet Bakshi, Mariam
Tuo, Wenbin
Aroian, Raffi V.
Zarlenga, Dante
author_sort Bakshi, Mariam
collection PubMed
description BACKGROUND: Haemonchus contortus is a blood-feeding, gastrointestinal nematode (GIN) that causes significant economic losses to the small ruminant industry worldwide. Despite extensive efforts, our understanding of the molecular mechanisms used by GIN to evade host immune responses is limited. Cathepsin B-like proteins (CBPs) are members of the cysteine protease family and are involved in parasite invasion and thus provide viable vaccine candidates. METHODS: In silico comparative analysis was used to identify conserved proteins among a subset of clade V parasitic nematodes with emphasis on blood-feeding worms, among which CBPs appeared prominently. We identified and characterized two novel CBPs designated Hc-CBP-1 and Hc-CBP-2. Rabbit anti-recombinant (r) Hc-CBP-1 and rHc-CBP-2 were used to detect the presence of native proteins in the excretory secretory products (ESP) and in worm tissues of adult H. contortus. Peptide arrays of rHc-CBP-1 and rHc-CBP-2 were screened with the homologous and heterologous anti-sera and with sera from dexamethasone-treated (Dex(+)) and non-treated (Dex(−)) H. contortus-infected animals to identify key immunogenic peptides. Gene transcription of Hc-cbp-1 and Hc-cbp-2 was also performed on H. contortus-infected animals treated with Dex(+). Finally, the mature recombinant proteins were used to assess their abilities to modulate cell functions. RESULTS: Immunohistochemistry showed that both Hc-CBP-1 and Hc-CBP-2 are present on the brush borders of the intestine; Hc-CBP-2 was also present in the hypodermis of the body wall. Peptide displays screened with rabbit anti-rHc-CBP-1 and anti-rHc-CBP-2 revealed regions within the proteins where dominant and overlapping epitopes prevailed. ELISA results were consistent with only Hc-CBP-1 being present in H. contortus adult ESPs. H. contortus from Dex(+) animals exhibited a threefold increase in Hc-cbp-2 transcript while Hc-cbp-1 expression did not change. In contrast, comparisons of immunoreactivities of rHc-CBP-1 and rHc-CBP-2 peptide arrays to sera from Dex(+) and Dex(−) animals primarily showed changes in Hc-CBP-1 binding. Lastly, rHc-CBP-1 suppressed mRNA expression of bovine peripheral blood mononuclear cell cytokines/activation markers, including TNFα, IL-1, IL-6 and CD86. CONCLUSIONS: These results suggest that as secreted and cryptic proteins, respectively, Hc-CBP-1 and Hc-CBP-2 influence cellular and immunological activities that have interesting dynamics during infection and may provide viable immune-related targets for attenuating H. contortus infectivity. GRAPHIC ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13071-021-05010-y.
format Online
Article
Text
id pubmed-8603344
institution National Center for Biotechnology Information
language English
publishDate 2021
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-86033442021-11-19 Immune reactivity and host modulatory roles of two novel Haemonchus contortus cathepsin B-like proteases Bakshi, Mariam Tuo, Wenbin Aroian, Raffi V. Zarlenga, Dante Parasit Vectors Research BACKGROUND: Haemonchus contortus is a blood-feeding, gastrointestinal nematode (GIN) that causes significant economic losses to the small ruminant industry worldwide. Despite extensive efforts, our understanding of the molecular mechanisms used by GIN to evade host immune responses is limited. Cathepsin B-like proteins (CBPs) are members of the cysteine protease family and are involved in parasite invasion and thus provide viable vaccine candidates. METHODS: In silico comparative analysis was used to identify conserved proteins among a subset of clade V parasitic nematodes with emphasis on blood-feeding worms, among which CBPs appeared prominently. We identified and characterized two novel CBPs designated Hc-CBP-1 and Hc-CBP-2. Rabbit anti-recombinant (r) Hc-CBP-1 and rHc-CBP-2 were used to detect the presence of native proteins in the excretory secretory products (ESP) and in worm tissues of adult H. contortus. Peptide arrays of rHc-CBP-1 and rHc-CBP-2 were screened with the homologous and heterologous anti-sera and with sera from dexamethasone-treated (Dex(+)) and non-treated (Dex(−)) H. contortus-infected animals to identify key immunogenic peptides. Gene transcription of Hc-cbp-1 and Hc-cbp-2 was also performed on H. contortus-infected animals treated with Dex(+). Finally, the mature recombinant proteins were used to assess their abilities to modulate cell functions. RESULTS: Immunohistochemistry showed that both Hc-CBP-1 and Hc-CBP-2 are present on the brush borders of the intestine; Hc-CBP-2 was also present in the hypodermis of the body wall. Peptide displays screened with rabbit anti-rHc-CBP-1 and anti-rHc-CBP-2 revealed regions within the proteins where dominant and overlapping epitopes prevailed. ELISA results were consistent with only Hc-CBP-1 being present in H. contortus adult ESPs. H. contortus from Dex(+) animals exhibited a threefold increase in Hc-cbp-2 transcript while Hc-cbp-1 expression did not change. In contrast, comparisons of immunoreactivities of rHc-CBP-1 and rHc-CBP-2 peptide arrays to sera from Dex(+) and Dex(−) animals primarily showed changes in Hc-CBP-1 binding. Lastly, rHc-CBP-1 suppressed mRNA expression of bovine peripheral blood mononuclear cell cytokines/activation markers, including TNFα, IL-1, IL-6 and CD86. CONCLUSIONS: These results suggest that as secreted and cryptic proteins, respectively, Hc-CBP-1 and Hc-CBP-2 influence cellular and immunological activities that have interesting dynamics during infection and may provide viable immune-related targets for attenuating H. contortus infectivity. GRAPHIC ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13071-021-05010-y. BioMed Central 2021-11-19 /pmc/articles/PMC8603344/ /pubmed/34798906 http://dx.doi.org/10.1186/s13071-021-05010-y Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/ (https://creativecommons.org/publicdomain/zero/1.0/) ) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
spellingShingle Research
Bakshi, Mariam
Tuo, Wenbin
Aroian, Raffi V.
Zarlenga, Dante
Immune reactivity and host modulatory roles of two novel Haemonchus contortus cathepsin B-like proteases
title Immune reactivity and host modulatory roles of two novel Haemonchus contortus cathepsin B-like proteases
title_full Immune reactivity and host modulatory roles of two novel Haemonchus contortus cathepsin B-like proteases
title_fullStr Immune reactivity and host modulatory roles of two novel Haemonchus contortus cathepsin B-like proteases
title_full_unstemmed Immune reactivity and host modulatory roles of two novel Haemonchus contortus cathepsin B-like proteases
title_short Immune reactivity and host modulatory roles of two novel Haemonchus contortus cathepsin B-like proteases
title_sort immune reactivity and host modulatory roles of two novel haemonchus contortus cathepsin b-like proteases
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8603344/
https://www.ncbi.nlm.nih.gov/pubmed/34798906
http://dx.doi.org/10.1186/s13071-021-05010-y
work_keys_str_mv AT bakshimariam immunereactivityandhostmodulatoryrolesoftwonovelhaemonchuscontortuscathepsinblikeproteases
AT tuowenbin immunereactivityandhostmodulatoryrolesoftwonovelhaemonchuscontortuscathepsinblikeproteases
AT aroianraffiv immunereactivityandhostmodulatoryrolesoftwonovelhaemonchuscontortuscathepsinblikeproteases
AT zarlengadante immunereactivityandhostmodulatoryrolesoftwonovelhaemonchuscontortuscathepsinblikeproteases