Analyze Diet
PloS one2022; 17(3); e0264911; doi: 10.1371/journal.pone.0264911

Effects of equine SALSA on neutrophil phagocytosis and macrophage cytokine production.

Abstract: Salivary scavenger and agglutinin (SALSA) is a secreted protein with various immunomodulatory roles. In humans, the protein agglutinates and inactivates microorganisms, and inhibits the release of pro-inflammatory cytokines. Saliva, which is rich in SALSA, accelerates bacterial phagocytosis, but SALSA's contribution is unclear. In horses, the functions of SALSA in inflammation remain undetermined, so they were investigated through phagocytosis and cytokine assays. Equine SALSA was purified from duodenal tissue, which contains abundant SALSA. To assess phagocytosis, fluorescently-labelled bacteria were incubated with 20, 10, 5, or 2.5 μg/mL of SALSA or phosphate buffered saline (PBS), and then incubated at 37°C or on ice with whole blood from seven healthy horses. Fluorescence was measured by gating on neutrophils using a flow cytometer, and compared between groups. To assess effects on cytokine production, alveolar macrophages were isolated from bronchoalveolar lavage fluid of five healthy horses and cultured in serum-free media for 24 hours with different concentrations of SALSA plus 1 μg/mL lipopolysaccharide (LPS), only LPS, or only media. Cytokines were measured in supernatant using an equine-specific multiplex bead immunoassay. There was significantly greater phagocytosis in samples incubated at 37°C compared to incubation on ice. Samples incubated with 20 μg/mL of SALSA at 37°C had less phagocytosis compared to samples with 10 or 2.5 μg/mL SALSA, or PBS. Alveolar macrophages incubated with SALSA plus LPS released significantly less CXC motif chemokine ligand 1, interleukin-8, interleukin-10, and tumor necrosis factor α, and more granulocyte colony stimulating factor (G-CSF), compared to macrophages incubated with LPS alone. These findings indicate anti-inflammatory effects, which may be due to interference with toll-like receptor 4 recognition of LPS or downstream signaling. Increase in G-CSF following incubation with SALSA suggests a novel mechanism for immunoregulation of alveolar macrophages by SALSA, addressing a knowledge gap regarding its functions in horses.
Publication Date: 2022-03-14 PubMed ID: 35286327PubMed Central: PMC8920288DOI: 10.1371/journal.pone.0264911Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research explores the immunomodulatory roles of equine SALSA (Salivary scavenger and agglutinin) in promoting bacterial phagocytosis and how it affects the production of specific cytokines in horses.

Overview of the Methodology

  • The study obtained equine SALSA from duodenal tissue, known to be rich in SALSA.
  • For observing phagocytosis, fluorescently-labelled bacteria were treated with various concentrations of SALSA or phosphate-buffered saline (PBS) and then mixed with whole blood harvested from seven healthy horses.
  • The samples were incubated either at 37°C or on ice, and phagocytosis rates were measured using a flow cytometer.
  • For assessing SALSA’s effect on cytokine production, alveolar macrophages were harvested from bronchoalveolar lavage fluid in five horses and were cultured in serum-free media for 24 hours.
  • The media contained varying concentrations of SALSA and 1 μg/mL lipopolysaccharide (LPS), only LPS, or only media, after which cytokine levels were measured using an equine-specific multiplex bead immunoassay.

Findings

  • Samples incubated at 37°C showed significantly greater phagocytosis rates compared to those incubated on ice.
  • Phagocytosis was seen to decrease in samples treated with 20 μg/mL of SALSA compared to those treated with lower concentrations of SALSA or PBS.
  • Alveolar macrophages treated with SALSA and LPS produced significantly lower amounts of certain cytokines, implying anti-inflammatory effects.
  • SALSA induced an increase in granulocyte colony-stimulating factor (G-CSF) production, indicating potential novel mechanisms for immunoregulation by SALSA.

Conclusions and Implications

  • The study’s findings suggest that equine SALSA has anti-inflammatory effects, likely due to inhibition of toll-like receptor 4 recognition of LPS or interference with downstream signaling.
  • The noted increase in G-CSF suggests that SALSA could be a key player in regulating the immune functions of alveolar macrophages, which helps fill knowledge gaps regarding SALSA’s immunomodulatory roles in horses.

Cite This Article

APA
Lee GKC, Kang H, Beeler-Marfisi J, Sears W, Lillie BN, Bienzle D. (2022). Effects of equine SALSA on neutrophil phagocytosis and macrophage cytokine production. PLoS One, 17(3), e0264911. https://doi.org/10.1371/journal.pone.0264911

Publication

ISSN: 1932-6203
NlmUniqueID: 101285081
Country: United States
Language: English
Volume: 17
Issue: 3
Pages: e0264911
PII: e0264911

Researcher Affiliations

Lee, Gary Kwok Cheong
  • Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
Kang, Heng
  • Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
Beeler-Marfisi, Janet
  • Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
Sears, William
  • Department of Population Medicine, University of Guelph, Guelph, Ontario, Canada.
Lillie, Brandon N
  • Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
Bienzle, Dorothee
  • Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.

MeSH Terms

  • Animals
  • Cytokines / metabolism
  • Granulocyte Colony-Stimulating Factor / metabolism
  • Horses
  • Ice
  • Lipopolysaccharides / metabolism
  • Lipopolysaccharides / pharmacology
  • Macrophages / metabolism
  • Neutrophils / metabolism
  • Phagocytosis
  • Tumor Necrosis Factor-alpha / metabolism

Conflict of Interest Statement

The authors have declared that no competing interests exist.

References

This article includes 44 references
  1. Reichhardt MP, Holmskov U, Meri S. SALSA-A dance on a slippery floor with changing partners.. Mol Immunol 2017 Sep;89:100-110.
    doi: 10.1016/j.molimm.2017.05.029pubmed: 28668353google scholar: lookup
  2. Reichhardt MP, Loimaranta V, Lea SM, Johnson S. Structures of SALSA/DMBT1 SRCR domains reveal the conserved ligand-binding mechanism of the ancient SRCR fold.. Life Sci Alliance 2020 Apr;3(4).
    doi: 10.26508/lsa.201900502pmc: PMC7043408pubmed: 32098784google scholar: lookup
  3. Kang W, Reid KB. DMBT1, a regulator of mucosal homeostasis through the linking of mucosal defense and regeneration?. FEBS Lett 2003 Apr 10;540(1-3):21-5.
    doi: 10.1016/s0014-5793(03)00217-5pubmed: 12681477google scholar: lookup
  4. Mitoma M, Oho T, Shimazaki Y, Koga T. Inhibitory effect of bovine milk lactoferrin on the interaction between a streptococcal surface protein antigen and human salivary agglutinin.. J Biol Chem 2001 May 25;276(21):18060-5.
    doi: 10.1074/jbc.M101459200pubmed: 11279204google scholar: lookup
  5. Ligtenberg AJ, Bikker FJ, De Blieck-Hogervorst JM, Veerman EC, Nieuw Amerongen AV. Binding of salivary agglutinin to IgA.. Biochem J 2004 Oct 1;383(Pt 1):159-64.
    doi: 10.1042/BJ20040265pmc: PMC1134054pubmed: 15228387google scholar: lookup
  6. Madsen J, Sorensen GL, Nielsen O, Tornøe I, Thim L, Fenger C, Mollenhauer J, Holmskov U. A variant form of the human deleted in malignant brain tumor 1 (DMBT1) gene shows increased expression in inflammatory bowel diseases and interacts with dimeric trefoil factor 3 (TFF3).. PLoS One 2013;8(5):e64441.
  7. Holmskov U, Mollenhauer J, Madsen J, Vitved L, Gronlund J, Tornoe I, Kliem A, Reid KB, Poustka A, Skjodt K. Cloning of gp-340, a putative opsonin receptor for lung surfactant protein D.. Proc Natl Acad Sci U S A 1999 Sep 14;96(19):10794-9.
    doi: 10.1073/pnas.96.19.10794pmc: PMC17962pubmed: 10485905google scholar: lookup
  8. Rosenstiel P, Sina C, End C, Renner M, Lyer S, Till A, Hellmig S, Nikolaus S, Fölsch UR, Helmke B, Autschbach F, Schirmacher P, Kioschis P, Hafner M, Poustka A, Mollenhauer J, Schreiber S. Regulation of DMBT1 via NOD2 and TLR4 in intestinal epithelial cells modulates bacterial recognition and invasion.. J Immunol 2007 Jun 15;178(12):8203-11.
    doi: 10.4049/jimmunol.178.12.8203pubmed: 17548659google scholar: lookup
  9. Itzek A, Chen Z, Merritt J, Kreth J. Effect of salivary agglutination on oral streptococcal clearance by human polymorphonuclear neutrophil granulocytes.. Mol Oral Microbiol 2017 Jun;32(3):197-210.
    doi: 10.1111/omi.12164pmc: PMC5116291pubmed: 27194631google scholar: lookup
  10. Li J, Metruccio MME, Evans DJ, Fleiszig SMJ. Mucosal fluid glycoprotein DMBT1 suppresses twitching motility and virulence of the opportunistic pathogen Pseudomonas aeruginosa.. PLoS Pathog 2017 May;13(5):e1006392.
  11. Park BS, Lee JO. Recognition of lipopolysaccharide pattern by TLR4 complexes.. Exp Mol Med 2013 Dec 6;45(12):e66.
    doi: 10.1038/emm.2013.97pmc: PMC3880462pubmed: 24310172google scholar: lookup
  12. Lee GKC, Tessier L, Bienzle D. Salivary Scavenger and Agglutinin (SALSA) Is Expressed in Mucosal Epithelial Cells and Decreased in Bronchial Epithelium of Asthmatic Horses.. Front Vet Sci 2019;6:418.
    doi: 10.3389/fvets.2019.00418pmc: PMC6896824pubmed: 31850379google scholar: lookup
  13. Tessier L, Côté O, Clark ME, Viel L, Diaz-Méndez A, Anders S, Bienzle D. Impaired response of the bronchial epithelium to inflammation characterizes severe equine asthma.. BMC Genomics 2017 Sep 8;18(1):708.
    doi: 10.1186/s12864-017-4107-6pmc: PMC5591550pubmed: 28886691google scholar: lookup
  14. Tessier L, Côté O, Clark ME, Viel L, Diaz-Méndez A, Anders S, Bienzle D. Gene set enrichment analysis of the bronchial epithelium implicates contribution of cell cycle and tissue repair processes in equine asthma.. Sci Rep 2018 Nov 6;8(1):16408.
    doi: 10.1038/s41598-018-34636-9pmc: PMC6219531pubmed: 30401798google scholar: lookup
  15. Lavoie-Lamoureux A, Leclere M, Lemos K, Wagner B, Lavoie JP. Markers of systemic inflammation in horses with heaves.. J Vet Intern Med 2012 Nov-Dec;26(6):1419-26.
  16. Ambruosi B, Accogli G, Douet C, Canepa S, Pascal G, Monget P, Moros Nicolás C, Holmskov U, Mollenhauer J, Robbe-Masselot C, Vidal O, Desantis S, Goudet G. Deleted in malignant brain tumor 1 is secreted in the oviduct and involved in the mechanism of fertilization in equine and porcine species.. Reproduction 2013 Aug;146(2):119-33.
    doi: 10.1530/REP-13-0007pubmed: 23722152google scholar: lookup
  17. Beeler-Marfisi J, Clark ME, Wen X, Sears W, Huber L, Ackerley C, Viel L, Bienzle D. Experimental induction of recurrent airway obstruction with inhaled fungal spores, lipopolysaccharide, and silica microspheres in horses.. Am J Vet Res 2010 Jun;71(6):682-9.
    doi: 10.2460/ajvr.71.6.682pubmed: 20513185google scholar: lookup
  18. Antrobus R, Borner GH. Improved elution conditions for native co-immunoprecipitation.. PLoS One 2011 Mar 23;6(3):e18218.
  19. Hartmann P, Becker R, Franzen C, Schell-Frederick E, Römer J, Jacobs M, Fätkenheuer G, Plum G. Phagocytosis and killing of Mycobacterium avium complex by human neutrophils.. J Leukoc Biol 2001 Mar;69(3):397-404.
    pubmed: 11261786
  20. Dalia AB, Weiser JN. Minimization of bacterial size allows for complement evasion and is overcome by the agglutinating effect of antibody.. Cell Host Microbe 2011 Nov 17;10(5):486-96.
    doi: 10.1016/j.chom.2011.09.009pmc: PMC3222866pubmed: 22100164google scholar: lookup
  21. Champion JA, Walker A, Mitragotri S. Role of particle size in phagocytosis of polymeric microspheres.. Pharm Res 2008 Aug;25(8):1815-21.
    doi: 10.1007/s11095-008-9562-ypmc: PMC2793372pubmed: 18373181google scholar: lookup
  22. Leito JT, Ligtenberg AJ, van Houdt M, van den Berg TK, Wouters D. The bacteria binding glycoprotein salivary agglutinin (SAG/gp340) activates complement via the lectin pathway.. Mol Immunol 2011 Oct;49(1-2):185-90.
    doi: 10.1016/j.molimm.2011.08.010pubmed: 21920605google scholar: lookup
  23. Martin EM, Messenger KM, Sheats MK, Jones SL. Misoprostol Inhibits Lipopolysaccharide-Induced Pro-inflammatory Cytokine Production by Equine Leukocytes.. Front Vet Sci 2017;4:160.
    doi: 10.3389/fvets.2017.00160pmc: PMC5624997pubmed: 29034249google scholar: lookup
  24. Curto E, Messenger KM, Salmon JH, Gilger BC. Cytokine and chemokine profiles of aqueous humor and serum in horses with uveitis measured using multiplex bead immunoassay analysis.. Vet Immunol Immunopathol 2016 Dec;182:43-51.
    doi: 10.1016/j.vetimm.2016.09.008pubmed: 27863549google scholar: lookup
  25. Zak A, Siwinska N, Elzinga S, Barker VD, Stefaniak T, Schanbacher BJ, Place NJ, Niedzwiedz A, Adams AA. Effects of advanced age and pituitary pars intermedia dysfunction on components of the acute phase reaction in horses.. Domest Anim Endocrinol 2020 Jul;72:106476.
  26. Kawai T, Akira S. Toll-like receptors and their crosstalk with other innate receptors in infection and immunity.. Immunity 2011 May 27;34(5):637-50.
    doi: 10.1016/j.immuni.2011.05.006pubmed: 21616434google scholar: lookup
  27. Losa García JE, Rodríguez FM, Martín de Cabo MR, García Salgado MJ, Losada JP, Villarón LG, López AJ, Arellano JL. Evaluation of inflammatory cytokine secretion by human alveolar macrophages.. Mediators Inflamm 1999;8(1):43-51.
    doi: 10.1080/09629359990711pmc: PMC1781780pubmed: 10704089google scholar: lookup
  28. Chanteux H, Guisset AC, Pilette C, Sibille Y. LPS induces IL-10 production by human alveolar macrophages via MAPKinases- and Sp1-dependent mechanisms.. Respir Res 2007 Oct 4;8(1):71.
    doi: 10.1186/1465-9921-8-71pmc: PMC2080632pubmed: 17916230google scholar: lookup
  29. Mubarak RA, Roberts N, Mason RJ, Alper S, Chu HW. Comparison of pro- and anti-inflammatory responses in paired human primary airway epithelial cells and alveolar macrophages.. Respir Res 2018 Jun 25;19(1):126.
    doi: 10.1186/s12931-018-0825-9pmc: PMC6020222pubmed: 29940963google scholar: lookup
  30. De Filippo K, Dudeck A, Hasenberg M, Nye E, van Rooijen N, Hartmann K, Gunzer M, Roers A, Hogg N. Mast cell and macrophage chemokines CXCL1/CXCL2 control the early stage of neutrophil recruitment during tissue inflammation.. Blood 2013 Jun 13;121(24):4930-7.
    doi: 10.1182/blood-2013-02-486217pubmed: 23645836google scholar: lookup
  31. Dorrington MG, Fraser IDC. NF-κB Signaling in Macrophages: Dynamics, Crosstalk, and Signal Integration.. Front Immunol 2019;10:705.
    doi: 10.3389/fimmu.2019.00705pmc: PMC6465568pubmed: 31024544google scholar: lookup
  32. Mantovani A, Sica A, Sozzani S, Allavena P, Vecchi A, Locati M. The chemokine system in diverse forms of macrophage activation and polarization.. Trends Immunol 2004 Dec;25(12):677-86.
    doi: 10.1016/j.it.2004.09.015pubmed: 15530839google scholar: lookup
  33. Liu X, Yin S, Chen Y, Wu Y, Zheng W, Dong H, Bai Y, Qin Y, Li J, Feng S, Zhao P. LPS‑induced proinflammatory cytokine expression in human airway epithelial cells and macrophages via NF‑κB, STAT3 or AP‑1 activation.. Mol Med Rep 2018 Apr;17(4):5484-5491.
    doi: 10.3892/mmr.2018.8542pubmed: 29393460google scholar: lookup
  34. Pinilla-Vera M, Xiong Z, Zhao Y, Zhao J, Donahoe MP, Barge S, Horne WT, Kolls JK, McVerry BJ, Birukova A, Tighe RM, Foster WM, Hollingsworth J, Ray A, Mallampalli R, Ray P, Lee JS. Full Spectrum of LPS Activation in Alveolar Macrophages of Healthy Volunteers by Whole Transcriptomic Profiling.. PLoS One 2016;11(7):e0159329.
  35. Agbanoma G, Li C, Ennis D, Palfreeman AC, Williams LM, Brennan FM. Production of TNF-α in macrophages activated by T cells, compared with lipopolysaccharide, uses distinct IL-10-dependent regulatory mechanism.. J Immunol 2012 Feb 1;188(3):1307-17.
    doi: 10.4049/jimmunol.1100625pubmed: 22219323google scholar: lookup
  36. Ernst O, Glucksam-Galnoy Y, Bhatta B, Athamna M, Ben-Dror I, Glick Y, Gerber D, Zor T. Exclusive Temporal Stimulation of IL-10 Expression in LPS-Stimulated Mouse Macrophages by cAMP Inducers and Type I Interferons.. Front Immunol 2019;10:1788.
    doi: 10.3389/fimmu.2019.01788pmc: PMC6691811pubmed: 31447835google scholar: lookup
  37. Müller H, Nagel C, Weiss C, Mollenhauer J, Poeschl J. Deleted in malignant brain tumors 1 (DMBT1) elicits increased VEGF and decreased IL-6 production in type II lung epithelial cells.. BMC Pulm Med 2015 Apr 8;15:32.
    doi: 10.1186/s12890-015-0027-xpmc: PMC4426184pubmed: 25885541google scholar: lookup
  38. Fukui H, Sekikawa A, Tanaka H, Fujimori Y, Katake Y, Fujii S, Ichikawa K, Tomita S, Imura J, Chiba T, Fujimori T. DMBT1 is a novel gene induced by IL-22 in ulcerative colitis.. Inflamm Bowel Dis 2011 May;17(5):1177-88.
    doi: 10.1002/ibd.21473pubmed: 20824812google scholar: lookup
  39. Roberts AW. G-CSF: a key regulator of neutrophil production, but that's not all!. Growth Factors 2005 Mar;23(1):33-41.
    doi: 10.1080/08977190500055836pubmed: 16019425google scholar: lookup
  40. Yamaguchi T, Miyata Y, Hayamizu K, Hashizume J, Matsumoto T, Tashiro H, Ohdan H. Preventive effect of G-CSF on acute lung injury via alveolar macrophage regulation.. J Surg Res 2012 Nov;178(1):378-84.
    doi: 10.1016/j.jss.2011.12.026pubmed: 22459288google scholar: lookup
  41. Boneberg EM, Hareng L, Gantner F, Wendel A, Hartung T. Human monocytes express functional receptors for granulocyte colony-stimulating factor that mediate suppression of monokines and interferon-gamma.. Blood 2000 Jan 1;95(1):270-6.
    pubmed: 10607712
  42. Wen Q, Kong Y, Zhao HY, Zhang YY, Han TT, Wang Y, Xu LP, Zhang XH, Huang XJ. G-CSF-induced macrophage polarization and mobilization may prevent acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.. Bone Marrow Transplant 2019 Sep;54(9):1419-1433.
    doi: 10.1038/s41409-019-0449-9pubmed: 30683906google scholar: lookup
  43. Martins A, Han J, Kim SO. The multifaceted effects of granulocyte colony-stimulating factor in immunomodulation and potential roles in intestinal immune homeostasis.. IUBMB Life 2010 Aug;62(8):611-7.
    doi: 10.1002/iub.361pmc: PMC2916186pubmed: 20681025google scholar: lookup
  44. Davis KU, Sheats MK. Bronchoalveolar Lavage Cytology Characteristics and Seasonal Changes in a Herd of Pastured Teaching Horses.. Front Vet Sci 2019;6:74.
    doi: 10.3389/fvets.2019.00074pmc: PMC6426765pubmed: 30923711google scholar: lookup

Citations

This article has been cited 0 times.