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Maternal cellular immunity to fetal HY antigens during pregnancy
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Symposium Abstracts / Journal of Reproductive Immunology 90 (2011) 131–163
S24 Maternal cellular immunity to fetal HY antigens during pregnancy D. Lissauer a,∗ , K. Piper b , O. Goodyear b , P.A.H. Moss b , M.D. Kilby a a
School of Clinical and Experimental Medicine (Reproduction, Genes & Development), United Kingdom b School of Cancer Sciences, University of Birmingham, Birmingham B15 2TG, United Kingdom Introduction: During pregnancy there is intimate cellular interaction between mother and fetus, with maternal immunological awareness of the allogenic pregnancy. In addition to the decidual maternal-fetal interface there is a peripheral interface due to the transplacental ‘traffic’ of fetal cells and material into the maternal circulation. Fetal cells may also persist after pregnancy, a phenomenon termed ‘fetal microchimerism’. A maternal cellular immune response to fetal minorhistocompatibility HY antigens can be detected after pregnancy. This can influence stem cell transplantation outcomes if parous female donors are used. It may also be important in recurrent miscarriage. However, the development, dynamics, phenotype and function of these fetal specific T cells during human pregnancy was not well understood. Murine models are inconsistent, but some suggest that during pregnancy CD8 T cells specific for fetal (HY) antigens may be deleted or rendered unresponsive. We investigated if a maternal CD8 T cell immune response to fetal (HY) antigens may be detected during human pregnancy, the dynamics of this response and if fetal specific T cells isolated prenatally differ in function compared to those isolated in the puerperium. Materials and methods: Pregnant women without any medical complications and non pregnant multiparous women of the appropriate HLA type (A*0201 and B*0702) were investigated. A cohort of pregnant women was also studied longitudinally prenatally and within the puerperium. We used technology of HLA-peptide ‘dextramers’ to detect fetal (HY) specific T cells; both directly ‘ex vivo’ with the phenotype of fetal specific cells examined by 9 colour flow cytometry and following expansion in short term culture. Fetal specific T cells were also cloned by limiting dilution and functional assessment of these clones was performed. Results: Maternal CD8 T cell responses to fetal (HY) antigen were detected at the same frequency during and after pregnancy. There was no difference in the magnitude of these responses. There was also no evidence of deletion of HY specific T cells during pregnancy, instead there was a significant increase in the frequency of these cells as pregnancy progressed. Fetal specific cells were detected directly ex vivo during pregnancy, have a memory phenotype and proliferate in culture. HY specific T cell clones were isolated from maternal blood during pregnancy and in the puerperium. These clones were cytotoxic and release IFN-␥ in response to fetal antigen, with no difference in function between clones isolated prenatally or after pregnancy.
Conclusion: Maternal CD8 T cell responses to fetal HY minor-histocompatibility antigens can be detected during human pregnancy from the 1st trimester, with the response increasing as pregnancy progresses. Unlike in murine models we found no evidence of deletion or transient unresponsiveness of these fetal specific T cells during pregnancy. These findings have potentially important implications for disorders of pregnancy and tumor immunology and transplantation. Keywords: Pregnancy; T-cell; HY; Fetal doi:10.1016/j.jri.2011.06.026 S25 Study of MHC class I molecules associations: Is receptor interaction at the cell-surface important at the fetomaternal interface? A. Jabeen ∗ , P.P. Laissue, P. Jain, A. Shakhawat, V. Shaikly, N. Fernández Department of Biological Sciences, University of Essex, Colchester, Essex, United Kigdom Introduction: The biological significance of the selective expression of MHC on trophoblast cells is not well understood. Extravillous trophoblast cells invade the maternal decidua and are intimately in contact with maternal immune effector cells. The unique MHC class I expression pattern on invasive extravillous trophoblast shows that classical transplantation antigens HLA-A and HLA-B expression is down-regulated; these cells however, express HLA-G, HLA-E and HLA-C. The expression of MHC class Ib products with limited polymorphism (HLAG and HLA-E) or class Ia with limited expression half life (HLA-C) protect extravillous trophoblast cells from natural killer (NK)-like large granular lymphocytes (LGL)-mediated attack. Trophoblast expressed HLA-C, HLA-E and HLAG interacts with surface receptors on maternal immune effector cells and thus modulates the immune-tolerance at the feto-maternal interface. Among other techniques we employed a sensitive bioimaging method aimed at a detailed mapping of the interaction of HLA-E with HLA-C and HLA-G molecules expressed on trophoblast cell surface. Materials and methods: Trophoblast model cell lines JEG-3and ACH-3P were studied quantitatively for the expression of MHC class I antigens by flow cytometry and western blotting. Antigen expression on the cell surface was examined by confocal microscopy. Cell surface HLA-E was detected by MEM-E/07 primary and anti mouse IgG conjugated with Alexa fluor 488 antibodies. Cell surface HLA-C was captured with L31 primary and anti mouse IgG conjugated with Alexa fluor 555 antibodies. Images were acquired in both channels with Nikon confocal microscope using Nyquist resolution with optimised settings (e.g. for Alexa488/555 xy = 55 nm/pixel, z = 140 nm/pixel). This new colocalisation approach is object based, three dimensional and depends on local intensity of highly resolved receptors using sub-pixel resolution. Same algorithm has been used
Symposium Abstracts / Journal of Reproductive Immunology 90 (2011) 131–163
S24 Maternal cellular immunity to fetal HY antigens during pregnancy D. Lissauer a,∗ , K. Piper b , O. Goodyear b , P.A.H. Moss b , M.D. Kilby a a
School of Clinical and Experimental Medicine (Reproduction, Genes & Development), United Kingdom b School of Cancer Sciences, University of Birmingham, Birmingham B15 2TG, United Kingdom Introduction: During pregnancy there is intimate cellular interaction between mother and fetus, with maternal immunological awareness of the allogenic pregnancy. In addition to the decidual maternal-fetal interface there is a peripheral interface due to the transplacental ‘traffic’ of fetal cells and material into the maternal circulation. Fetal cells may also persist after pregnancy, a phenomenon termed ‘fetal microchimerism’. A maternal cellular immune response to fetal minorhistocompatibility HY antigens can be detected after pregnancy. This can influence stem cell transplantation outcomes if parous female donors are used. It may also be important in recurrent miscarriage. However, the development, dynamics, phenotype and function of these fetal specific T cells during human pregnancy was not well understood. Murine models are inconsistent, but some suggest that during pregnancy CD8 T cells specific for fetal (HY) antigens may be deleted or rendered unresponsive. We investigated if a maternal CD8 T cell immune response to fetal (HY) antigens may be detected during human pregnancy, the dynamics of this response and if fetal specific T cells isolated prenatally differ in function compared to those isolated in the puerperium. Materials and methods: Pregnant women without any medical complications and non pregnant multiparous women of the appropriate HLA type (A*0201 and B*0702) were investigated. A cohort of pregnant women was also studied longitudinally prenatally and within the puerperium. We used technology of HLA-peptide ‘dextramers’ to detect fetal (HY) specific T cells; both directly ‘ex vivo’ with the phenotype of fetal specific cells examined by 9 colour flow cytometry and following expansion in short term culture. Fetal specific T cells were also cloned by limiting dilution and functional assessment of these clones was performed. Results: Maternal CD8 T cell responses to fetal (HY) antigen were detected at the same frequency during and after pregnancy. There was no difference in the magnitude of these responses. There was also no evidence of deletion of HY specific T cells during pregnancy, instead there was a significant increase in the frequency of these cells as pregnancy progressed. Fetal specific cells were detected directly ex vivo during pregnancy, have a memory phenotype and proliferate in culture. HY specific T cell clones were isolated from maternal blood during pregnancy and in the puerperium. These clones were cytotoxic and release IFN-␥ in response to fetal antigen, with no difference in function between clones isolated prenatally or after pregnancy.
Conclusion: Maternal CD8 T cell responses to fetal HY minor-histocompatibility antigens can be detected during human pregnancy from the 1st trimester, with the response increasing as pregnancy progresses. Unlike in murine models we found no evidence of deletion or transient unresponsiveness of these fetal specific T cells during pregnancy. These findings have potentially important implications for disorders of pregnancy and tumor immunology and transplantation. Keywords: Pregnancy; T-cell; HY; Fetal doi:10.1016/j.jri.2011.06.026 S25 Study of MHC class I molecules associations: Is receptor interaction at the cell-surface important at the fetomaternal interface? A. Jabeen ∗ , P.P. Laissue, P. Jain, A. Shakhawat, V. Shaikly, N. Fernández Department of Biological Sciences, University of Essex, Colchester, Essex, United Kigdom Introduction: The biological significance of the selective expression of MHC on trophoblast cells is not well understood. Extravillous trophoblast cells invade the maternal decidua and are intimately in contact with maternal immune effector cells. The unique MHC class I expression pattern on invasive extravillous trophoblast shows that classical transplantation antigens HLA-A and HLA-B expression is down-regulated; these cells however, express HLA-G, HLA-E and HLA-C. The expression of MHC class Ib products with limited polymorphism (HLAG and HLA-E) or class Ia with limited expression half life (HLA-C) protect extravillous trophoblast cells from natural killer (NK)-like large granular lymphocytes (LGL)-mediated attack. Trophoblast expressed HLA-C, HLA-E and HLAG interacts with surface receptors on maternal immune effector cells and thus modulates the immune-tolerance at the feto-maternal interface. Among other techniques we employed a sensitive bioimaging method aimed at a detailed mapping of the interaction of HLA-E with HLA-C and HLA-G molecules expressed on trophoblast cell surface. Materials and methods: Trophoblast model cell lines JEG-3and ACH-3P were studied quantitatively for the expression of MHC class I antigens by flow cytometry and western blotting. Antigen expression on the cell surface was examined by confocal microscopy. Cell surface HLA-E was detected by MEM-E/07 primary and anti mouse IgG conjugated with Alexa fluor 488 antibodies. Cell surface HLA-C was captured with L31 primary and anti mouse IgG conjugated with Alexa fluor 555 antibodies. Images were acquired in both channels with Nikon confocal microscope using Nyquist resolution with optimised settings (e.g. for Alexa488/555 xy = 55 nm/pixel, z = 140 nm/pixel). This new colocalisation approach is object based, three dimensional and depends on local intensity of highly resolved receptors using sub-pixel resolution. Same algorithm has been used