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Human IgG1 Responses to Surface Localised Schistosoma mansoni Ly6 Family Members Drop following Praziquantel Treatment.

Chalmers IW, Fitzsimmons CM, Brown M, Pierrot C, Jones FM, Wawrzyniak JM, Fernandez-Fuentes N, Tukahebwa EM, Dunne DW, Khalife J, Hoffmann KF - PLoS Negl Trop Dis (2015)

Bottom Line: To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE) responses against two surface-bound representatives (SmLy6A and SmLy6B) within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment.Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0.001, respectively) when compared to rising IgG1 levels against sub-surface SmTAL1.Collectively, these results expand the number of SmLy6 proteins found within S. mansoni and specifically demonstrate that surface-associated SmLy6A and SmLy6B elicit immunological responses during infection in endemic communities.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological, Environmental & Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom.

ABSTRACT

Background: The heptalaminate-covered, syncytial tegument is an important anatomical adaptation that enables schistosome parasites to maintain long-term, intravascular residence in definitive hosts. Investigation of the proteins present in this surface layer and the immune responses elicited by them during infection is crucial to our understanding of host/parasite interactions. Recent studies have revealed a number of novel tegumental surface proteins including three (SmCD59a, SmCD59b and Sm29) containing uPAR/Ly6 domains (renamed SmLy6A SmLy6B and SmLy6D in this study). While vaccination with SmLy6A (SmCD59a) and SmLy6D (Sm29) induces protective immunity in experimental models, human immunoglobulin responses to representative SmLy6 family members have yet to be thoroughly explored.

Methodology/principal findings: Using a PSI-BLAST-based search, we present a comprehensive reanalysis of the Schistosoma mansoni Ly6 family (SmLy6A-K). Our examination extends the number of members to eleven (including three novel proteins) and provides strong evidence that the previously identified vaccine candidate Sm29 (renamed SmLy6D) is a unique double uPAR/Ly6 domain-containing representative. Presence of canonical cysteine residues, signal peptides and GPI-anchor sites strongly suggest that all SmLy6 proteins are cell surface-bound. To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE) responses against two surface-bound representatives (SmLy6A and SmLy6B) within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment. While pre-treatment IgG1 prevalence for SmLy6A and SmLy6B differs amongst the studied population (7.4% and 25.3% of the cohort, respectively), these values are both higher than IgG1 prevalence (2.7%) for a sub-surface tegumental antigen, SmTAL1. Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0.001, respectively) when compared to rising IgG1 levels against sub-surface SmTAL1.

Conclusions/significance: Collectively, these results expand the number of SmLy6 proteins found within S. mansoni and specifically demonstrate that surface-associated SmLy6A and SmLy6B elicit immunological responses during infection in endemic communities.

No MeSH data available.


Related in: MedlinePlus

SmLy6A and SmLy6B are both abundantly expressed in adult schistosomes but only SmLy6B is detectable in schistosomula.SmLy6A and SmLy6B mRNA and protein abundances were elucidated as described in the Materials and Methods. Transcription profiles of SmLy6A (A) and SmLy6B (B) were derived from the S. mansoni lifecycle microarray data available via Array express [10] under the experimental accession number E-MEXP-2094. Values are mean normalized fluorescence units ± sem (standard error of the mean). Recombinant SmLy6A (C) and SmLy6B (D) were cloned into a modified pET30a vector (Novagen), expressed using BL21 star cell line (Invitrogen) and purified from inclusion bodies using Ni-NTA affinity columns (Qiagen). (E) Anti-rSmLy6A polyclonal rat antisera recognises a ~10kDa native protein found within soluble extracts derived from mixed-sex 7-week old worms. (F) Anti-rSmLy6A polyclonal rat antisera recognises a ~10kDa native SmLy6B from 24 schistosomula and 7 week worms. Pre-bleed rat serum did not recognise either protein.
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pntd.0003920.g003: SmLy6A and SmLy6B are both abundantly expressed in adult schistosomes but only SmLy6B is detectable in schistosomula.SmLy6A and SmLy6B mRNA and protein abundances were elucidated as described in the Materials and Methods. Transcription profiles of SmLy6A (A) and SmLy6B (B) were derived from the S. mansoni lifecycle microarray data available via Array express [10] under the experimental accession number E-MEXP-2094. Values are mean normalized fluorescence units ± sem (standard error of the mean). Recombinant SmLy6A (C) and SmLy6B (D) were cloned into a modified pET30a vector (Novagen), expressed using BL21 star cell line (Invitrogen) and purified from inclusion bodies using Ni-NTA affinity columns (Qiagen). (E) Anti-rSmLy6A polyclonal rat antisera recognises a ~10kDa native protein found within soluble extracts derived from mixed-sex 7-week old worms. (F) Anti-rSmLy6A polyclonal rat antisera recognises a ~10kDa native SmLy6B from 24 schistosomula and 7 week worms. Pre-bleed rat serum did not recognise either protein.

Mentions: Using information available from a DNA microarray database [10], the mRNA abundance for 8 of the 11 SmLy6 genes (SmLy6A-D and F-I) across 14 different schistosome life-stages was deduced (S1 Fig). The results for SmLy6A (Fig 3A) and SmLy6B (Fig 3B) showed a similar trend (low/no expression in egg/snail-residing parasite stages, but rising abundance within mammalian-residing parasite stages). However, SmLy6B was more abundantly transcribed (~ 2–4X) in the earlier schistosomula stages analysed (3 hr—3 day) when compared to SmLy6A.


Human IgG1 Responses to Surface Localised Schistosoma mansoni Ly6 Family Members Drop following Praziquantel Treatment.

Chalmers IW, Fitzsimmons CM, Brown M, Pierrot C, Jones FM, Wawrzyniak JM, Fernandez-Fuentes N, Tukahebwa EM, Dunne DW, Khalife J, Hoffmann KF - PLoS Negl Trop Dis (2015)

SmLy6A and SmLy6B are both abundantly expressed in adult schistosomes but only SmLy6B is detectable in schistosomula.SmLy6A and SmLy6B mRNA and protein abundances were elucidated as described in the Materials and Methods. Transcription profiles of SmLy6A (A) and SmLy6B (B) were derived from the S. mansoni lifecycle microarray data available via Array express [10] under the experimental accession number E-MEXP-2094. Values are mean normalized fluorescence units ± sem (standard error of the mean). Recombinant SmLy6A (C) and SmLy6B (D) were cloned into a modified pET30a vector (Novagen), expressed using BL21 star cell line (Invitrogen) and purified from inclusion bodies using Ni-NTA affinity columns (Qiagen). (E) Anti-rSmLy6A polyclonal rat antisera recognises a ~10kDa native protein found within soluble extracts derived from mixed-sex 7-week old worms. (F) Anti-rSmLy6A polyclonal rat antisera recognises a ~10kDa native SmLy6B from 24 schistosomula and 7 week worms. Pre-bleed rat serum did not recognise either protein.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492491&req=5

pntd.0003920.g003: SmLy6A and SmLy6B are both abundantly expressed in adult schistosomes but only SmLy6B is detectable in schistosomula.SmLy6A and SmLy6B mRNA and protein abundances were elucidated as described in the Materials and Methods. Transcription profiles of SmLy6A (A) and SmLy6B (B) were derived from the S. mansoni lifecycle microarray data available via Array express [10] under the experimental accession number E-MEXP-2094. Values are mean normalized fluorescence units ± sem (standard error of the mean). Recombinant SmLy6A (C) and SmLy6B (D) were cloned into a modified pET30a vector (Novagen), expressed using BL21 star cell line (Invitrogen) and purified from inclusion bodies using Ni-NTA affinity columns (Qiagen). (E) Anti-rSmLy6A polyclonal rat antisera recognises a ~10kDa native protein found within soluble extracts derived from mixed-sex 7-week old worms. (F) Anti-rSmLy6A polyclonal rat antisera recognises a ~10kDa native SmLy6B from 24 schistosomula and 7 week worms. Pre-bleed rat serum did not recognise either protein.
Mentions: Using information available from a DNA microarray database [10], the mRNA abundance for 8 of the 11 SmLy6 genes (SmLy6A-D and F-I) across 14 different schistosome life-stages was deduced (S1 Fig). The results for SmLy6A (Fig 3A) and SmLy6B (Fig 3B) showed a similar trend (low/no expression in egg/snail-residing parasite stages, but rising abundance within mammalian-residing parasite stages). However, SmLy6B was more abundantly transcribed (~ 2–4X) in the earlier schistosomula stages analysed (3 hr—3 day) when compared to SmLy6A.

Bottom Line: To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE) responses against two surface-bound representatives (SmLy6A and SmLy6B) within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment.Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0.001, respectively) when compared to rising IgG1 levels against sub-surface SmTAL1.Collectively, these results expand the number of SmLy6 proteins found within S. mansoni and specifically demonstrate that surface-associated SmLy6A and SmLy6B elicit immunological responses during infection in endemic communities.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological, Environmental & Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom.

ABSTRACT

Background: The heptalaminate-covered, syncytial tegument is an important anatomical adaptation that enables schistosome parasites to maintain long-term, intravascular residence in definitive hosts. Investigation of the proteins present in this surface layer and the immune responses elicited by them during infection is crucial to our understanding of host/parasite interactions. Recent studies have revealed a number of novel tegumental surface proteins including three (SmCD59a, SmCD59b and Sm29) containing uPAR/Ly6 domains (renamed SmLy6A SmLy6B and SmLy6D in this study). While vaccination with SmLy6A (SmCD59a) and SmLy6D (Sm29) induces protective immunity in experimental models, human immunoglobulin responses to representative SmLy6 family members have yet to be thoroughly explored.

Methodology/principal findings: Using a PSI-BLAST-based search, we present a comprehensive reanalysis of the Schistosoma mansoni Ly6 family (SmLy6A-K). Our examination extends the number of members to eleven (including three novel proteins) and provides strong evidence that the previously identified vaccine candidate Sm29 (renamed SmLy6D) is a unique double uPAR/Ly6 domain-containing representative. Presence of canonical cysteine residues, signal peptides and GPI-anchor sites strongly suggest that all SmLy6 proteins are cell surface-bound. To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE) responses against two surface-bound representatives (SmLy6A and SmLy6B) within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment. While pre-treatment IgG1 prevalence for SmLy6A and SmLy6B differs amongst the studied population (7.4% and 25.3% of the cohort, respectively), these values are both higher than IgG1 prevalence (2.7%) for a sub-surface tegumental antigen, SmTAL1. Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0.001, respectively) when compared to rising IgG1 levels against sub-surface SmTAL1.

Conclusions/significance: Collectively, these results expand the number of SmLy6 proteins found within S. mansoni and specifically demonstrate that surface-associated SmLy6A and SmLy6B elicit immunological responses during infection in endemic communities.

No MeSH data available.


Related in: MedlinePlus