title: Pro-inflammatory cytokines, IFNgamma and TNFalpha, influence immune properties of human bone marrow and Wharton jelly mesenchymal stem cells differentially.
abstract: BACKGROUND
  Wharton's jelly derived stem cells (WJMSCs) are gaining attention as a possible clinical alternative to bone marrow derived mesenchymal stem cells (BMMSCs) owing to better accessibility, higher expansion potential and low immunogenicity. Usage of allogenic mesenchymal stem cells (MSC) could be permissible in vivo only if they retain their immune properties in an inflammatory setting. Thus the focus of this study is to understand and compare the immune properties of BMMSCs and WJMSCs primed with key pro-inflammatory cytokines, Interferon-gamma (IFNgamma) and Tumor Necrosis Factor-alpha (TNFalpha).
  
  
  RESULTS
  Initially the effect of priming on MSC mediated suppression of alloantigen and mitogen induced lymphoproliferation was evaluated in vitro. Treatment with IFNgamma or TNFalpha, did not ablate the immune-suppression caused by both the MSCs. Extent of immune-suppression was more with WJMSCs than BMMSCs in both the cases. Surprisingly, priming BMMSCs enhanced suppression of mitogen driven lymphoproliferation only; whereas IFNgamma primed WJMSCs were better suppressors of MLRs. Further, kinetic analysis of cytokine profiles in co-cultures of primed/unprimed MSCs and Phytohematoagglutinin (PHA) activated lymphocytes was evaluated. Results indicated a decrease in levels of pro-inflammatory cytokines. Interestingly, a change in kinetics and thresholds of Interleukin-2 (IL-2) secretion was observed only with BMMSCs. Analysis of activation markers on PHA-stimulated lymphocytes indicated different expression patterns in co-cultures of primed/unprimed WJMSCs and BMMSCs. Strikingly, co-culture with WJMSCs resulted in an early activation of a negative co-stimulatory molecule, CTLA4, which was not evident with BMMSCs. A screen for immune suppressive factors in primed/unprimed WJMSCs and BMMSCs indicated inherent differences in IFNgamma inducible Indoleamine 2, 3-dioxygenase (IDO) activity, Hepatocyte growth factor (HGF) and Prostaglandin E-2 (PGE2) levels which could possibly influence the mechanism of immune-modulation.
  
  
  CONCLUSIONS
  This study demonstrates that inflammation affects the immune properties of MSCs distinctly. Importantly different tissue derived MSCs could utilize unique mechanisms of immune-modulation.
authors.affiliation: Manipal Institute of Regenerative Medicine, Constituent Institute of Manipal University, Bangalore, Karnataka, India. jyothi.prasanna@manipal.edu
authors.forename: S Jyothi
authors.initials: SJ
authors.lastname: Prasanna
authors.forename: Divya
authors.initials: D
authors.lastname: Gopalakrishnan
authors.forename: Shilpa Rani
authors.initials: SR
authors.lastname: Shankar
authors.forename: Anoop Babu
authors.initials: AB
authors.lastname: Vasandan
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D001854:Bone Marrow Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018920:Coculture Techniques; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000235:genetics / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology*; D007959:Lymphocyte Culture Test, Mixed; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014470:Umbilical Cord / Q000166:cytology
chemical_list: D016207:Cytokines; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human