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Immunotherapy 2019 Immunology Case Reports | Volume 3
Page 11
May 22-23, 2019 | Rome, Italy
2nd Global Summit on OF EXCELLENCE
IN INTERNATIONAL
MEETINGS
YEARS
IMMUNOLOGY
AND CANCER THERAPY
SOLUBLE MHC CLASS II MOLECULES
IN IMMUNE REGULATION AGAINST
AUTOIMMUNITY
The involvement of major histocompatibility complex (MHC) antigens in the
regulation of immune response has been well defined over the years. During
the intracellular trafficking, from synthesis to antigen loading and transport
to the cell membrane MHC antigens find a way to be excreted by the cells,
since they can be found as soluble MHC class I (sMHCI) and class II (sMHCII)
molecules in all body fluids. Although secretion mechanisms have not been
sufficiently studied, sMHC molecules have been shown to display important
immunoregulatory properties. Concentrating on sMHCII molecules, latest
findings indicate that these are loaded with self-peptides and play an im-
portant role in tolerance maintenance. Antigen-specific tolerοgenic stimu-
lation has been shown to increase serum sMHCII levels as compared to the
corresponding immunogenic stimulus in mice in vitro as well as in vivo. Se-
rum isolated syngeneic sMHCII proteins were shown to stimulate spleen cell
proliferation, their major target being the CD4-positive cell population. At
the physiological level, sMHCII proteins were shown to suppress not only an
antigen-specific but also antigen-non-specific immune activation, correlat-
ed to increase of CD25 and CTLA-4 and decrease CD28 expression on naive
CD4-positive cells, decreased IL-2 and increased IL-10 production. In addition,
thesemolecules inhibited phosphorylation of ZAP-70 and especially LAT pro-
teins in the downstreampathways of TCR activation signalling. Taking advan-
tage of the above properties of sMHCII, these were applied on experimental
mousemodels of systemic lupus erythematosus (SLE) as well as autoimmune
hepatitis (AIH) and it was shown that syngeneic or allogeneic sMHCII proteins
could alleviate SLE and AIH symptoms in experimental mouse models in vitro
as well as in vivo, introducing thus the ability of sMHCII proteins to suppress
specific autoantigen responses, opening new areas of research and offering
novel therapeutic approaches to SLE and AIHwith expanding features to oth-
er autoimmune diseases.
Irene Athanassakis, Immunol Case Rep 2019, Volume 3
Irene Athanassakis is a Professor of Immunology
at University of Crete, Greece. She obtained her
PhD in Immunology from the Medical School of
the University of Alberta, Canada. She has pub-
lished 114 papers and book reviews and has
given more than 70 invited talks in international
meetings and has 180 abstracts in congresses
with H-index 21; 154 co-authors; RG score=36.98
and more than 1500 citations. She is an active re-
viewer for 19 international journals.
Irene Athanassakis
University of Crete, Greece
BIOGRAPHY
Keynote Forum | Day 1