Summary
Infections with Trichuris trichiura and other trichurid nematodes have been reported to display protective effects against atopy, allergic and autoimmune diseases. The aims of the present study were to investigate the immunomodulatory properties of T. trichiura adult worm extract (TtE) and its fractions (TtEFs) on the production of cytokines by peripheral blood mononuclear cells and to identify their proteinaceous components. Fourteen TtEFs were obtained by ion exchange chromatography and tested for effects on cytokine production by peripheral blood mononuclear cells. The molecular constituents of the six most active fractions were evaluated using nano-LC/mass spectrometry. The homology between T. trichiura and the related nematode Trichinella spiralis was used to identify 12 proteins in TtEFs. Among those identified, fructose biphosphate aldolase, a homologue of macrophage migration inhibitory factor and heat-shock protein 70 may contribute to the immunomodulatory effects of TtEFs. The identification of such proteins could lead to the development of novel drugs for the therapy of allergic and other inflammatory diseases.
Keywords: cytokine, immunoregulation, peripheral blood mononuclear cells, proteomics, Trichuris spp
Research Note
There are compelling epidemiological data showing that the prevalence of allergic and autoimmune diseases have increased considerably over recent decades among children living in urban centres of low- and middle-income countries (1). The hygiene hypothesis provides an explanation for such temporal trends in the prevalence of inflammatory diseases (2, 3). Some intestinal helminth infections have been associated with protection against inflammatory diseases (3), among them, epidemiological studies and clinical trial using Trichurid infection have reported protection against atopy, asthma and autoimmune diseases (4–6). In addition, helminth extracts and their molecules regulating specific pathways of the immune response in vitro have been identified (7, 8).
In this study, the immunomodulatory effects of fractions from T. trichiura adult worms extract on cytokine responses by human peripheral blood monocytes (PBMCs) in vitro were investigated and mass spectrometry was used to identify the proteinaceous content within the active fractions that could be mediating these effects. To our knowledge, no similar research has been done using extracts isolated from this human trichuroid helminth.
T. trichiura adult worms were isolated from infected Ecuadorian children (9) treated with pyrantel pamoate and bisacodyl. Ethical approval for obtaining of stool sample from the children was provided by the Ethical Committee of the Universidad San Francisco de Quito, Ecuador. The written informed consent was provided by the parents or guardians. The worms (5 g – wet weight) were washed in 0.15 m phosphate-buffered saline pH 7.4 and their extract was prepared in a tissue grinder in the presence of zirconium/silica beads (BioSpec Products, Inc., Bartlesville, OK, USA) and 20 mm TRIS-HCl pH 8, containing a mix of protease inhibitors (1 mm phenylmethanesulphonyl fluoride, 50 μm tosyl phenylalanyl chloromethyl ketone, 50 μm tosyllysinechloromethylketone and 2 mm ethylenediaminetetracetate; SIGMA-Aldrich, St. Louis, MO, USA), yielding 200 mg of protein. The extract was subjected to ion exchange chromatography using a salt gradient elution, on a Mono Q 5/50 column (GE Healthcare, São Paulo, SP, Brazil). The 14 collected fractions (TtEF-1 to TtEF-14) were dialysed against RPMI 1640.
PBMCs, obtained from eight 21- to 40-year-old healthy adults, were incubated in 96-well plates (2 x 105 cells/well) in a humidified atmosphere of 5% CO2 at 37°C in RPMI 1640 medium (GIBCO, Grand Island, NY, USA), supplemented with 10% fetal bovine serum (GIBCO), 1% glutamine, 100 U/mL penicillin, 100 μg/mL streptomycin and 20 μg/mL polymyxin B (SIGMA-Aldrich, St. Louis, MO, USA). Subsequently, the cells were cultured in the presence and absence of 50 μg/mL of protein from each TtEF or TtE. This amount was the optimal concentration obtained in an assay using 12.5-100 μg/mL of these antigens to test IL-10 production by stimulated PBMCs (data not shown). Ethical approval for collecting blood from the donors was provided by the Ethical Committee of the Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Proposal 179/2008, Project no. 277. All subjects provided written informed consent. Lipopolysacharide (LPS) from E. coli (4 UE/mL; SIGMA-Aldrich) and phytohemagglutinin (PHA, 5 μg/mL; SIGMA-Aldrich) were used as positive controls. The inhibitory effects of TtEFs on cytokine production were assessed by coculturing the PBMCs with each TtEF or TtE in the presence of either LPS (4 UE/mL), for evaluating IL-10 and TNF-α; or LPS (4 UE/mL) plus IFN-γ (100 ng/mL; BD Bioscience, San Diego, CA, USA), for IL-12 p40; or PHA (5 μg/mL), for IL-5 and IL-13. PBMCs cultured with LPS or PHA in the absence of TtEF or TtE were used as controls.
Culture supernatants were collected after 24 h of culture for IL-10, IL-12 p40 and TNF-α production, and after 120 h for IL-5 and IL-13. Cytokines were measured using capture ELISA kit according to the manufacturers instructions (Pharmingen, BD Biosciences, San Diego, CA, USA). Production of cytokines by stimulated or inhibited by TtE or TtEFs PBMCs was compared with those control cultures using paired analyses, with Wilcoxon signed rank test. P values ≤ 0.05 were considered statistically significant.
For mass spectrometry analysis, aliquots of the six most active TtEFs corresponding to 150 μg of proteins each were dried and resuspended in 100 μL of NH4HCO3 (50 mm, pH 9.7) in duplicate, reduced by incubation with 5 μL of 200 mm dithiothreitol in 100 mm NH4HCO3 at 95°C for 5 min and alkylated with 4 μL of 500 mm iodoacetamide in 100 mm NH4HCO3 for 45 min at room temperature in the dark. The reaction was halted with 5 μL of 200 mM dithiothreitol in 100 mm NH4HCO3. Digestion was done using sequencing-grade trypsin (Promega Biotecnologia, São Paulo, SP, Brazil) at 1/50 (w/w) trypsin/protein at 37°C overnight. Tryptic peptides were desalted using Macro Trap™ cartridges following the manufacturers instructions (Michrom BioResources, Auburn, CA, USA).
Peptide separation was carried out by liquid chromatography (nanoACQUITY UPLC™, Waters Corporation, Milford, MA, USA) in duplicate. Peptides from the trypsin digest (3 μL) were loaded at a flow rate of 5 μL/min onto a Symmetry C18 trap column (Waters Corporation) for 2 min, using 0.1% formic acid (FA)/3% acetonitrile (ACN) in water as eluent. Peptides were eluted from the trap column with a step gradient using solvent B (0.1% FA in ACN) and separated on a BEH 130 C18 column (Waters Corporation) at a flow rate of 0.6 μL/min.
Mass detection of peptides was carried out on a hybrid quadrupole-time-of-flight mass spectrometer (Q-TOF micro, Micromass, Alliedscienpro, Quebec, Canada) equipped with a nanoelectrospray Z spray source. Data directed analyses acquired in survey mode were processed using MassLynx (v 4.1, Waters Corporation) and searched against SwissProt-UniProt database of the Trichocephalida order, downloaded in August 2011. Data searches used the Protein Lynx Global Server v 2.5 (PLGS). PLGS minimizes false positive results arising from the existence of homologue proteins in the database searched by combining several filtering and scoring factors. Search parameters were set for peptide tolerance of 100 ppm, fragment mass tolerance of 0.1 Da and estimated calibration error of 0.005 Da. The enzyme entry was set for trypsin and the maximum number of missed cleavages to 1. IAA alkylation of cysteine (carbamidomethyl C) and methionine oxidation were set as fixed and variable modifications respectively. Search results were automatically validated when at least three consecutive measured fragment ions of a peptide matched theoretical b- or y-fragment ions of a known protein sequence tag. The entire data set of identified proteins was further selected by considering only the proteins that replicated in both technical instrument duplicates with a likelihood of identification higher than 95% and PLGS score higher than 9 (a statistical measurement calculated by PLGS search engine using Monte Carlo algorithm that indicates the identification accuracy. It depends on several factors, and among them is the number of entries in the database, the peak area, the number of matched/unmatched peptides, fragmentation data, etc.). The highest PLGS score value obtained in this experiment was 9.696. Only the proteins that had two or more identified peptides were considered to be present in the fraction.
Our research group has demonstrated previously that whole blood from children infected with T. trichiura produces IL-10 when stimulated with parasite antigen (10); that T. trichiura infections are inversely associated with skin prick test (SPT) reactivity to common allergens (4) and that infections in early life are associated with a reduced prevalence of SPT reactivity later in childhood (5). These observations are now extended in this study, in which is shown that some fractions of T. trichiura somatic extract (TtEF-6 and TtEF-8 through TtEF-14) are able to stimulate the production of IL-10 (Table 1; Figure S1) and induce the production of TNF-α and IL-12 p40 by PBMCs from naïve donors in stimulatory assays (Table 1), despite inhibiting them in inhibitory assay (Table 1; Figure S2 and Figure S3). These findings and the chromatographic profile of TtE (Fig. 1) indicate that the assessed fractions of the extract may contain distinct molecules capable of inducing dissimilar inflammatory effects, which is in agreement with the known inflammatory manifestations of helminth infection that are observed particularly during early infections (11–13). None of the fractions stimulated the production of the Th2 cytokines IL-5 and IL-13 (data not shown), but fractions TtEF-8 to TtEF-10 significantly inhibited the production of IL-5 by PBMCs stimulated with PHA (Table 1; Figure S4). Downregulation of IL-5 have been described as a feature of a modified Th2 response, which would lead to reduced eosinophil involvement (14). A modified Th2 response appears to be a mechanism to lessen potentially damaging Th2-associated inflammation (15) and would indirectly decrease an allergic response. TtEF-9 and TtEF-10 inhibited the PHA-induced IL-13 production (Table 1; Figure S5). This cytokine is involved in the induction of pulmonary inflammation and especially in mucus production by airway goblet cells (16, 17). TtEF-9 had the most potent regulatory properties among the tested fractions and was also associated with inhibition of LPS-induced TNF-α and IL-12 p40 (Table 1). This work shows the advantage of using fractions of TtE because this approach can separate parasite components with low or no immune regulatory activity, such as TtEF-13 that did not inhibit cytokine production, from components with intermediate effect and components with high immunoregulatory potential. In the whole extract, molecules with immune regulatory activity maybe masked by other inactive components.
Table 1.
Summary of the production of cytokines by PBMCs stimulated with Trichuris trichiura somatic extract (TtE) and its fractions (TtEFs), and respective proteins identified by mass spectrometry comparing by homology with other parasites of the Trichocephalida order
| Tested samples | aStimulatory effects on cytokine productions | binhibitory effects on cytokine productions | cProtein content with potential immunoregulatory effect | ||||||
|---|---|---|---|---|---|---|---|---|---|
| IL-10 | TNF-α | IL-12 p40 | IL-10 | TNF-α | IL-12 p40 | IL-5 | IL-13 | ||
| TtE | 203.1 (37.8) | 333 (110.2) | 99.06 (39.5) | 62.9 (80.4) | 149.9 (59.5) | 227.2 (68.7) | 85.5 (45.1) | 96.93 (251.4) | – |
| TtEF-6 | 704.7 (102.9) | 404.4 (119.9) | 122.1 (36) | 89.08 (63.1) | 450.2 (111.6) | 243 (122.4) | 54.77 (48.3) | 332.1 (297.9) | FBPA; MIFH; PEPCK |
| TtEF-8 | 461.3 (102.5) | 290.6 (94.5) | 94.77 (49.8) | 101.4 (65.2) | 543.5 (204.8) | 317.9 (151.5) | 125.9 (63.8) | 360.9 (202.3) | FBPA; MIFH; HSP70; PEPCK |
| TtEF-9 | 340.2 (73) | 310.9 (132.7) | 78.13 (35.5) | 78.31 (89.3) | 590 (149.5) | 462.6 (183.2) | 140.3 (59.6) | 711 (253.3) | FBPA; MIFH |
| TtEF-10 | 486.7 (139.3) | 402.2 (167.7) | 84.66 (49.3) | 72.73 (48) | 803 (149.3) | 369.2 (160.9) | 77.68 (25) | 485.2 (194.6) | HSP70; PEPCK |
| TtEF-11 | 595.2 (140.9) | 448.8 (159.2) | 53.87 (16.4) | 36.47 (60.3) | 643.8 (119.3) | 374.1 (130.9) | 112 (59.1) | 18.56 (174) | FBPA |
| TtEF-12 | 641.5 (99.8) | 618.2 (157.5) | 178.6 (79.9) | 102.9 (89.2) | 490.1 (145.8) | 245.4 (112.9) | 122.3 (65.4) | 44.36 (242.9) | FBPA |
| TtEF-13 | 309.1 (120.2) | 258.6 (81.5) | 143.9 (79.1) | 164.4 (90.7) | 108.3 (45.7) | 33.09 (37) | 60.9 (73) | 329 (297.1) | – |
| TtEF-14 | 213 (45.4) | 244.9 (82.1) | 70.13 (25.4) | 91.71 (34.5) | 262.5 (38.2) | 142.4 (61.5) | 57.97 (20.5) | 323.4 (220.6) | – |
Stimulatory effects on cytokine production. Peripheral blood mononuclear cells (PBMCs) were cultured in the presence of 50 μg/mL of either TtE or TtEFs; the results were expressed as the increase in cytokine concentrations in pg/mL plus the standard error of the mean, comparing antigen-stimulated and nonstimulated cells
inhibitory effects on cytokine production. PBMCs were stimulated with either a suboptimal dose of LPS (4 UE/mL), for evaluating inhibition of IL-10 and TNF-α; or LPS (4 UE/mL) plus IFN-γ (100 ηg/mL), for IL-12 p40; or PHA (5 μg/mL). for IL-5 and IL-13, and cocultured with TtE or TtEFs. The results were expressed as the decrease in cytokine concentrations in pg/mL plus the standard error of the mean, comparing LPS and IFN-γ stimulated cells in the absence or presence of TtE and TtEFs. Bold numbers are those statistically significant at P < 0.05 (for Wilcoxon signed rank test)
FBPA, fructose biphosphate aldolase; MIFH, macrophage migration inhibitory factor homologue; HSP 70, heat-shock protein 70; PEPCK, phosphoenolpyruvate carboxykinase.
Figure 1.
Chromatographic profile of T. trichiura somatic extract obtained by ion exchange fractionation. Green legend represents the salt gradient elution (0–1m NaCl). Absorbance was monitored at 280 gm in milli-absorbance unit (mAU). U and respective numbers correspond to the collected fractions TtEf-2 to TtEF-14, which are delimited by vertical straight lines.
Because there are very limited data available for the T. trichiura genome, the identification of most proteins in the active fractions of TtEF was accomplished by comparing homology with Trichinella spirallis, a nematode from the Trichocephalida order, that shows marked antigenic cross-reactivity with T. trichiura (18) and has also demonstrated regulatory activity against autoimmune diseases in experimental animal models (19, 20). Approximately 1300 proteins (probability > 95%) were identified from the six most active fractions (TtEF-6, TtEF-8 through TtEF-12), but only 13 proteins were doubly identified in replicate samples and their identification validated according to the search engine parameters specified in the methodology (Table S1). Some proteins were found in more than one of the active fractions. Macrophage migration inhibitory factor homologue (MIFH) was the only protein directly identified from T. trichiura and was present in TtEF-6, TtEF-8 and TtEF-9 (Table S1). MIFH has been shown to be produced by several parasites and is thought to have an important role in the evasion mechanism within the host, mimicking the action of the human MIF (15). MIFH from intestinal parasites has several recognized immune modulatory effects on intestinal and allergic airways inflammation (21, 22) and acts through the recruitment of monocytes and regulatory T cells (23, 24), decreasing Th2 cytokine production by PBMCs from atopic asthma patients and increasing IL-10 and TGF-β production (22, 25). Fructose biphosphate aldolase (FBPA), which was present in all fractions except TtEF-10, and phosphoenolpyruvate carboxykinase, present in TtEF-6, TtEF-8 and TtEF-10 (Table S1), are essential proteins involved in the parasite life cycle as well in the establishment of infection, and also may play a modulatory role in the immune response (26, 27). Likewise, the heat-shock protein 70 (HSP 70), present in TtEF-8 and TtEF-10, may have immune regulatory properties similar to those described for Schistosoma japonicum (28, 29).
The data shown in this work present evidence that protein fractions from T. trichiura have immune modulatory effects on PBMCs from naïve individuals and provide some important clues as to the proteins that may be relevant in mediating these effects. These proteins could be considered for further evaluation as novel therapeutic tools for the treatment or prevention of allergic and autoimmune diseases. In addition, they support the immune regulatory effects that have been associated with T. trichiura infection.
Supplementary Material
Induction of IL-10 production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMCs) from healthy donors. The IL-10 level in culture supernatants was assayed by ELISA. PBMCs were cultured for 24 h either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0.05 (in relation to the differences between the two groups of PBMC).
Inhibition of TNF-α production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMC) from healthy donors. All PBMC were stimulated with bacterial lipopolysaccharide. The TNF-α levels in culture supernatants were assayed by ELISA. The PBMC were cultured for 24 h either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0·05 (in relation to the differences between the two groups of PBMC).
Inhibition of IL-12 p40 production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMCs) from healthy donors. All PBMC were stimulated with bacterial lipopolysaccharide. The IL-12 p40 level in culture supernatants were assayed by ELISA. PBMCs were cultured for 24 h either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0·05 (in relation to the differences between the two groups of PBMC).
Inhibition of IL-5 production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMCs) from healthy donors. All PBMC were stimulated with phytohemoagglutinin. The IL-5 level in culture supernatants was assayed by ELISA. PBMCs were cultured for 5 days either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0·05; **P < 0.01 (in relation to the differences between the two groups of PBMC).
Inhibition of IL-13 production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMCs) from healthy donors. All PBMC were stimulated with phytohemoagglutinin. The IL-5 level in culture supernatants were assayed by ELISA. PBMCs were cultured for 5 days either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0·05 (in relation to the differences between the two groups of PBMC).
Acknowledgements
The authors are grateful to the Mass Spectrometry Core Facility of Centro de Pesquisas Gonçalo Moniz for allowing the proteomics analysis. This study was partially supported by Ministério da Ciência e Tecnologia (INCT/MCT/CNPq Programme; Contract no. 5737862008 and MCT-CNPq - Edital n° 015/2008) and SCAALA (Social Change of Asthma and Allergy in Latin America - Programme, funded by the WELLCOME TRUST, grant no. 072405/Z/03/Z). WELLCOME TRUST, CNPq, CAPES and FAPESB provided scholarships for some of the authors.
Footnotes
Disclosures: All authors have no conflict of interest.
References
- 1.Asher MI. Urbanisation, asthma and allergies. Thorax. 2011;66:1025–1026. doi: 10.1136/thoraxjnl-2011-201019. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Cooke A. Review series on helminths, immune modulation and the hygiene hypothesis: how might infection modulate the onset of type 1 diabetes? Immunology. 2009;126:12–17. doi: 10.1111/j.1365-2567.2008.03009.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Rook G. Review series on helminths, immune modulation and the hygiene hypothesis: the broader implications of the hygiene hypothesis. Immunology. 2009;126:3–11. doi: 10.1111/j.1365-2567.2008.03007.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Moncayo AL, Vaca M, Oviedo G, et al. Risk factors for atopic and non-atopic asthma in a rural area of Ecuador. Thorax. 2010;65:409–416. doi: 10.1136/thx.2009.126490. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Rodrigues L, Newcombe P, Cunha S, et al. Early infection with Trichuris trichiura and allergen skin test reactivity in later childhood. Clin Exp Allergy. 2008;38:1769–1777. doi: 10.1111/j.1365-2222.2008.03027.x. [DOI] [PubMed] [Google Scholar]
- 6.Summers R, Elliott D, Qadir K, Urban JJ, Thompson R, Weinstock J. Trichuris suis seems to be safe and possibly effective in the treatment of inflammatory bowel disease. Am J Gastroenterol. 2003;98:2034–2041. doi: 10.1111/j.1572-0241.2003.07660.x. [DOI] [PubMed] [Google Scholar]
- 7.Cardoso L, Oliveira S, Góes A, et al. Schistosoma mansoni. antigens modulate the allergic response in a murine model of ovalbumin-induced airway inflammation. Clin Exp Immunol. 2010;160:266–274. doi: 10.1111/j.1365-2249.2009.04084.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Harnett W, McInnes I, Harnett M. ES-62, a filarial nematode-derived immunomodulator with anti-inflammatory potential. Immunol Lett. 2004;94:27–33. doi: 10.1016/j.imlet.2004.04.008. [DOI] [PubMed] [Google Scholar]
- 9.Cooper PJ, Chico ME, Vaca MG, et al. Risk factors for asthma and allergy associated with urban migration: background and methodology of a cross-sectional study in Afro-Ecuadorian school children in North-eastern Ecuador (Esmeraldas-SCAALA Study) BMC Pulm Med. 2006;6:24. doi: 10.1186/1471-2466-6-24. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Figueiredo CA, Barreto ML, Rodrigues LC, et al. Chronic intestinal helminth infections are associated with immune hyporesponsiveness and induction of a regulatory network. Infect Immun. 2010;78:3160–3167. doi: 10.1128/IAI.01228-09. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Smits HH, Everts B, Hartgers FC, Yazdanbakhsh M. Chronic helminth infections protect against allergic diseases by active regulatory processes. Curr Allergy Asthma Rep. 2010;10:3–12. doi: 10.1007/s11882-009-0085-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Schönemeyer A, Lucius R, Sonnenburg B, et al. Modulation of human T cell responses and macrophage functions by onchocystatin, a secreted protein of the filarial nematode Onchocerca volvulus. J Immunol. 2001;167:3207–3215. doi: 10.4049/jimmunol.167.6.3207. [DOI] [PubMed] [Google Scholar]
- 13.Alcântara-Neves NM, Badaró SJ, dos Santos MC, Pontes-de-Carvalho L, Barreto ML. The presence of serum anti-Ascaris lumbricoides IgE antibodies and of Trichuris trichiura infection are risk factors for wheezing and/or atopy in preschool-aged Brazilian children. Respir Res. 2010;11:114. doi: 10.1186/1465-9921-11-114. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Samitas K, Rådinger M, Bossios A. Current update on eosinophilic lung diseases and anti-IL-5 treatment. Recent Pat Antiinfect Drug Discov. 2011;6:189–205. doi: 10.2174/157489111796887855. [DOI] [PubMed] [Google Scholar]
- 15.Maizels RM, Yazdanbakhsh M. Immune regulation by helminth parasites: cellular and molecular mechanisms. Nat Rev Immunol. 2003;3:733–744. doi: 10.1038/nri1183. [DOI] [PubMed] [Google Scholar]
- 16.Hoshino T, Kato S, Oka N, et al. Pulmonary inflammation and emphysema: role of the cytokines IL-18 and IL-13. Am J Respir Crit Care Med. 2007;176:49–62. doi: 10.1164/rccm.200603-316OC. [DOI] [PubMed] [Google Scholar]
- 17.Walsh GM. Tralokinumab, an anti-IL-13 mAb for the potential treatment of asthma and COPD. Curr Opin Investig Drugs. 2010;11:1305–1312. [PubMed] [Google Scholar]
- 18.Roach TI, Wakelin D, Else KJ, Bundy DA. Antigenic cross-reactivity between the human whipworm, Trichuris trichiura and the mouse trichuroids Trichuris muris and Trichinella spiralis. Parasite Immunol. 1988;10:279–291. doi: 10.1111/j.1365-3024.1988.tb00221.x. [DOI] [PubMed] [Google Scholar]
- 19.Gruden-Movsesijan A, Ilic N, Mostarica-Stojkovic M, Stosic-Grujicic S, Milic M, Sofronic-Milosavljevic L. Mechanisms of modulation of experimental autoimmune encephalomyelitis by chronic Trichinella spiralis infection in Dark Agouti rats. Parasite Immunol. 2010;32:450–459. doi: 10.1111/j.1365-3024.2010.01207.x. [DOI] [PubMed] [Google Scholar]
- 20.Saunders K, Raine T, Cooke A, Lawrence C. Inhibition of autoimmune type 1 diabetes by gastrointestinal helminth infection. Infect Immun. 2007;75:397–407. doi: 10.1128/IAI.00664-06. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Cho MK, Lee CH, Yu HS. Amelioration of intestinal colitis by macrophage migration inhibitory factor isolated from intestinal parasites through toll-like receptor 2. Parasite Immunol. 2011;33:265–275. doi: 10.1111/j.1365-3024.2010.01276.x. [DOI] [PubMed] [Google Scholar]
- 22.Park SK, Cho MK, Park HK, et al. Macrophage migration inhibitory factor homologs of Anisakis simplex suppress Th2 response in allergic airway inflammation model via CD4 + CD25 + Foxp3 + T cell recruitment. J Immunol. 2009;182:6907–6914. doi: 10.4049/jimmunol.0803533. [DOI] [PubMed] [Google Scholar]
- 23.Younis AE, Soblik H, Ajonina-Ekoti I, et al. Characterization of a secreted macrophage migration inhibitory factor homologue of the parasitic nematode Strongyloides acting at the parasite-host cell interface. Microbes Infect. 2012;14:279–289. doi: 10.1016/j.micinf.2011.09.006. [DOI] [PubMed] [Google Scholar]
- 24.Zhang Y, Miura K, Li J, et al. Macrophage migration inhibitory factor homolog from Plasmodium yoelii modulates monocyte recruitment and activation in spleen during infection. Parasitol Res. 2012;110:1755–1763. doi: 10.1007/s00436-011-2696-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Park HK, Cho MK, Park HY, et al. Macrophage migration inhibitory factor isolated from a parasite inhibited Th2 cytokine production in PBMCs of atopic asthma patients. J Asthma. 2012;49:10–15. doi: 10.3109/02770903.2011.637593. [DOI] [PubMed] [Google Scholar]
- 26.Asahi H, Osman A, Cook RM, Loverde PT, Stadecker MJ. Shistosoma mansoni phosphoenolpyruvate carboxykinase, a novel egg antigen: immunological properties of the recombinant protein and identification of a T-cell epitope. Infect Immun. 2000;68:3385–3393. doi: 10.1128/iai.68.6.3385-3393.2000. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Marques HH, Zouain CS, Torres CB, Oliveira JS, Alves JB, Goes AM. Protective effect and granuloma down-modulation promoted by RP44 antigen a fructose 1,6 bisphosphate aldolase of Schistosoma mansoni. Immunobiology. 2008;213:437–446. doi: 10.1016/j.imbio.2007.10.002. [DOI] [PubMed] [Google Scholar]
- 28.Hauet-Broere F, Wieten L, Guichelaar T, Berlo S, van der Zee R, Van Eden W. Heat shock proteins induce T cell regulation of chronic inflammation. Ann Rheum Dis. 2006;65(Suppl 3):iii65–iii68. doi: 10.1136/ard.2006.058495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Wang X, Zhou S, Chi Y, et al. CD4 + CD25 + Treg induction by an HSP60-derived peptide SJMHE1 from Schistosoma japonicum is TLR2 dependent. Eur J Immunol. 2009;39:3052–3065. doi: 10.1002/eji.200939335. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Induction of IL-10 production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMCs) from healthy donors. The IL-10 level in culture supernatants was assayed by ELISA. PBMCs were cultured for 24 h either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0.05 (in relation to the differences between the two groups of PBMC).
Inhibition of TNF-α production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMC) from healthy donors. All PBMC were stimulated with bacterial lipopolysaccharide. The TNF-α levels in culture supernatants were assayed by ELISA. The PBMC were cultured for 24 h either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0·05 (in relation to the differences between the two groups of PBMC).
Inhibition of IL-12 p40 production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMCs) from healthy donors. All PBMC were stimulated with bacterial lipopolysaccharide. The IL-12 p40 level in culture supernatants were assayed by ELISA. PBMCs were cultured for 24 h either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0·05 (in relation to the differences between the two groups of PBMC).
Inhibition of IL-5 production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMCs) from healthy donors. All PBMC were stimulated with phytohemoagglutinin. The IL-5 level in culture supernatants was assayed by ELISA. PBMCs were cultured for 5 days either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0·05; **P < 0.01 (in relation to the differences between the two groups of PBMC).
Inhibition of IL-13 production by somatic extract of T. trichiura (TtE) or its fractions in peripheral blood mononuclear cells (PBMCs) from healthy donors. All PBMC were stimulated with phytohemoagglutinin. The IL-5 level in culture supernatants were assayed by ELISA. PBMCs were cultured for 5 days either in the absence (Medium) or in the presence of the fraction (TtEF) indicated at the X axis. The lines represent each individual. *P < 0·05 (in relation to the differences between the two groups of PBMC).