A functional role for soluble HLA-G antigens in immune modulation mediated by mesenchymal stromal cells

作者：Rizzo R; Campioni D; Stignani M; Melchiorri L; Bagnara G P; Bonsi L; Alviano F; Lanzoni G; Moretti S; Cuneo A; Lanza F; Baricordi O R^*

来源：Cytotherapy, 2008, 10(4): 364-375.

DOI：10.1080/14653240802105299

• HLA-G
• immunoregulation
• interleukin-10
• lymphoproliferation
• mesenchymal stromal cells

Background It has been suggested that soluble factors produced by bone marrow (BM) mesenchymal stromal cells (MSC) play a fundamental role in mediating immune modulation. HLA-G antigens (Ag) are major histocompatibility complex (MHC) class Ib molecules characterized by a limited polymorphism and a splicing mechanism that regulates the production of membrane-bound and soluble isoforms. Interleukin-10 (IL-10) cytokine is one of the main up-modulators of soluble HLA-G Ag (sHLA-G) production by CD14(+) peripheral blood monocyte cells and increased IL-10 levels are reported to be associated with MSC immune modulation.
Methods We investigated, by specific enzyme-linked immunosorbent assay (ELISA), the possible role of sHLA-G molecules in the inhibition of the peripheral blood mononuclear cell (PBMC) response to phytohemagglutinin (PHA) mediated by MSC from different sources.
Results There was a significant correlation between the presence of increased levels of sHLA-G and IL-10 in the MSC/PBMC/PHA culture supernatants and lymphoproliferative inhibition. Neutralizing experiments performed with monoclonal Ab directed against HLA-G and IL-10 molecules confirmed the inhibitory ability of sHLA-G Ag. Furthermore, exogenous IL-10 induced sHLA-G molecule secretion by MSC alone in a polymorphic way, while a longitudinal analysis confirmed the loss of MSC inhibitory functions in relation to in vitro MSC aging.
Discussion Overall the results obtained suggest a functional role for sHLA-G molecules in inhibiting the PBMC response mediated by MSC. Moreover, the ability of IL-10 to induce sHLA-G Ag production by MSC alone could be proposed as a marker of MSC functional ability.

• 出版日期2008