Role of Myeloid-Derived Suppressor Cells in tumor-associated pregnancy

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Version: After imprimatur
Serval ID
serval:BIB_62D5E1C69F3D
Type
A Master's thesis.
Publication sub-type
Master (thesis) (master)
Collection
Publications
Institution
Title
Role of Myeloid-Derived Suppressor Cells in tumor-associated pregnancy
Author(s)
Waeber S.
Director(s)
Stamenkovic I.
Codirector(s)
Le-Bitoux M-A.
Institution details
Université de Lausanne, Faculté de biologie et médecine
Publication state
Accepted
Issued date
2012
Language
english
Number of pages
35
Abstract
Cancer progression is dependent, in part, on interactions between tumor cells and the host microenvironment. During pregnancy, physiological changes occur that include inflammation and reduced immunity, both of which can promote tumor growth. Accordingly, tumors are observed to be more aggressive and to have greater proclivity toward metastasis during pregnancy. In this work, myeloid-derived suppressor cells (MDSC), a population of heterogeneous and pluripotent cells that can down-regulate immune responses during pathological conditions, were studied in the context of mouse and human gestation. The gene expression profile of mouse MDSC has been shown to differ in pregnant and virgin mice, and the profile in pregnant animals bears similarity to that of MDSC associated with the tumor microenvironment. Common induced genes include Fibronectin1 and Olfactomedin4, which are known to be involved in extracellular matrix remodeling and tissue permissiveness to tumor cells implantation. Our observations suggest that mouse MDSC may represent a shared regulatory mechanism of tissue permissiveness that occurs during the physiological state of gestation and tumor growth.
Pregnancy-associated changes in immunosuppressive myeloid cell activity have also been studied in humans. We show that CD33+ myeloid cells isolated from PBMC (peripheral blood mononuclear cells) of pregnant women are more strongly immunosuppressive on T cells than CD33+ cells removed from non-pregnant subjects. During murine gestation, decreased natural killer (NK) cell activity is responsible, at least in part, for the increase in experimental metastasis. However, although peripheral blood NK cell numbers and cytotoxicity were slightly reduced in pregnant women, neither appeared to be regulated by CD33+ cells. Nevertheless, based on its observed suppression of T cell responses, the CD33+ PBMC subset appears to be an appropriate myeloid cell population to study in order to elucidate mechanisms of immune regulation that occur during human pregnancy. Our findings regarding the immunosuppressive function of CD33+cells and the role of NK cells during human pregnancy are consistent with the notion that changes in the function of the immune system participate in the constitution of a permissive soil for tumour progression.
Keywords
cancer, metastasis, immune system, Myeloid-Derived Suppressor Cells, pregnancy
Create date
10/09/2013 9:31
Last modification date
20/08/2019 14:19
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