Effective antibody responses are essential to generate protective humoral immunity. Different inf... more Effective antibody responses are essential to generate protective humoral immunity. Different inflammatory signals polarize T cells towards an appropriate effector phenotype during an infection or immunization. Th1 and Th2 cells have been associated with the polarization of humoral responses for several decades. However, it is now established that T follicular helper cells (Tfh) have a unique ability to access the B cell follicle and support the Germinal Centre (GCs) responses by providing help to B cells. We investigated the specialization of Tfh cells induced under type-1 and type-2 conditions. We first studied homogenous Tfh cell populations generated by adoptively transferred TCR-transgenic T cells in mice immunized with type-1 and type-2 adjuvants. Using a machine learning approach, we established a gene expression signature that discriminates Tfh cells polarized towards type-1 and type-2 response, defined as Tfh1 and Tfh2 cells. The Tfh1 and Tfh2 distinct signature was validat...
Increased number of circulating myeloid cells is a hallmark of most cancers, however it remains u... more Increased number of circulating myeloid cells is a hallmark of most cancers, however it remains unclear how primary tumors impact on myelopoiesis. Here we show that non-metastatic breast tumors remotely instruct the fate of long-term hematopoietic stem cell (HSCLT) in the bone marrow. We found that HSCLT from tumor bearing mice acquire a myeloid bias persisting upon primary and secondary HSCLT transfer in lethally-irradiated tumor-free animals. By imaging the bone marrow HSC niche, we found that the tumor-bearing status is associated with increased physical interactions between mesenchymal stem/stromal cells (MSC) and HSCLT. Moreover, ex vivo co-culture experiments demonstrate that MSC isolated from tumor-bearing mice increase myeloid differentiation of HSCLT isolated from tumor free mice. In summary, our data reveal that breast cancer remotely promotes myelopoiesis at the earliest stages of hematopoietic differentiation in the BM mesenchymal niche.
IL-2 reverses established type 1 diabetes in NOD mice by a local effect on pancreatic regulatory ... more IL-2 reverses established type 1 diabetes in NOD mice by a local effect on pancreatic regulatory T cells
Reactive oxygen species (ROS) are major contributors to neuropathology in both Multiple sclerosis... more Reactive oxygen species (ROS) are major contributors to neuropathology in both Multiple sclerosis and other neurodegenerative disorders. ROS are small molecules with unpaired electrons, making them highly reactive and their actions need to be tightly regulated. ROS can initiate oxidative degradation of poly unsaturated lipids in the cell membrane leading to lipid peroxidation. In this process other reactive compounds are generated, among which 4-hydroxynonenal (4-HNE) is one. 4-HNE is in itself neurotoxic and has been associated with neurodegenerative diseases and occurs in MS lesions. The most efficient defense against free 4-HNE is Glutathione-S-transferase 4 alpha (Gsta4), which ligates HNE to glutathione. We have studied the influence of allelic variation in Gsta4 in combination with its transgenic modified expression in two models of inflammation/neurodegeneration; controlled contusion traumatic brain injury (TBI) and experimental autoimmune encephalomyelitis (EAE). Susceptibility was compared between Dark Agouti (DA), a congenic rat strain on DA backgroundwith a small chromosome 8 fragment containing an expression quantitative trait locus for Gsta4 and a Gsta4 transgenic strain on DA background. We find that high Gsta4 mRNA and protein levels correlate with increased nerve cell survival in the TBI model as well as after intrathecal 4-HNE administration. Allelic variation in Gsta4 does not statistically significantly affect the EAE score over 50 days, although there is a trend of improvedEAE score in the higherGsta4 expressing congenic strain. At the moment these findings are being repeated in the Gsta4 transgenic strain. Our data stresses Gsta4 as a key player in acute and chronic nerve cell degenerating conditions.
Tumor-infiltrating CD8 + T cells progressively lose functionality and fail to reject tumors. The ... more Tumor-infiltrating CD8 + T cells progressively lose functionality and fail to reject tumors. The underlying mechanism and re-programing induced by checkpoint blockers are incompletely understood. We show here that genetic ablation or pharmacological inhibition of histone lysine methyltransferase Suv39h1 delays tumor growth and potentiates tumor rejection by anti-PD-1. In the absence of Suv39h1, anti-PD-1 induces alternative activation pathways allowing survival and differentiation of IFNγ and Granzyme B producing effector cells that express negative checkpoint molecules, but do not reach final exhaustion. Their transcriptional program correlates with that of melanoma patients responding to immune-checkpoint blockade and identifies the emergence of cytolytic-effector tumor-infiltrating lymphocytes as a biomarker of clinical response. Anti-PD-1 favors chromatin opening in loci linked to T-cell activation, memory and pluripotency, but in the absence of Suv39h1, cells acquire accessibil...
Macrophage infiltration is a hallmark of solid cancers, and overall macrophage infiltration corre... more Macrophage infiltration is a hallmark of solid cancers, and overall macrophage infiltration correlates with lower patient survival and resistance to therapy. Tumor-associated macrophages, however, are phenotypically and functionally heterogeneous. Specific subsets of tumor-associated macrophage might be endowed with distinct roles on cancer progression and antitumor immunity. Here, we identify a discrete population of FOLR2+ tissue-resident macrophages in healthy mammary gland and breast cancer primary tumors. FOLR2+ macrophages localize in perivascular areas in the tumor stroma, where they interact with CD8+ T cells. FOLR2+ macrophages efficiently prime effector CD8+ T cells ex vivo. The density of FOLR2+ macrophages in tumors positively correlates with better patient survival. This study highlights specific roles for tumor-associated macrophage subsets and paves the way for subset-targeted therapeutic interventions in macrophages-based cancer therapies.
Senescent T cells have been described during aging, chronic infections, and cancer; however, a co... more Senescent T cells have been described during aging, chronic infections, and cancer; however, a comprehensive study of the phenotype, function, and transcriptional program of this T cell population in breast cancer (BC) patients is missing. Compared to healthy donors (HDs), BC patients exhibit an accumulation of KLRG-1+CD57+ CD4+ and CD8+ T cells in peripheral blood. These T cells infiltrate tumors and tumor-draining lymph nodes. KLRG-1+CD57+ CD4+ and CD8+ T cells from BC patients and HDs exhibit features of senescence, and despite their inhibitory receptor expression, they produce more effector cytokines and exhibit higher expression of Perforin, Granzyme B, and CD107a than non-senescent subsets. When compared to blood counterparts, tumor-infiltrating senescent CD4+ T cells show similar surface phenotype but reduced cytokine production. Transcriptional profiling of senescent CD4+ T cells from the peripheral blood of BC patients reveals enrichment in genes associated with NK or CD8+-...
The invention relates to pharmaceutical compositions using a polypeptide comprising at least one ... more The invention relates to pharmaceutical compositions using a polypeptide comprising at least one CXXC motif, such as Giardia parasite's variable surface proteins (VSP) or a fragment thereof to raise by oral or mucosal vaccination an immune response against a heterologous selected antigen, such as tumor antigen, microbial antigen or other antigen.
Changes in the oral microbiome, particularly Fusobacterium nucleatum, are associated with oral sq... more Changes in the oral microbiome, particularly Fusobacterium nucleatum, are associated with oral squamous cell carcinoma (OSCC). F. nucleatum has been reported to modulate local immunity in cancers. We aimed to assess the association between intratumoral F. nucleatum and clinico-pathological features, relapse, and overall survival (OS) in two independent cohorts of patients with OSCC, and to explore the interplay with immune-related genes. We retrospectively analyzed tissue samples from a first cohort of 122 patients with head and neck squamous cell carcinoma, including 61 OSCC (cohort #1), and a second cohort of 90 additional OSCC (cohort #2). We then performed a sensitivity analysis on the merged cohort of OSCC patients (N = 151). F. nucleatum 16S rRNA gene sequences were quantified using real-time quantitative PCR. The presence of gram-negative bacteria and macrophages was confirmed by LPS and CD163 immunostainings, respectively. F. nucleatum positivity was associated with older ag...
Cholangiocarcinoma (CCA) results from the malignant transformation of cholangiocytes. Primary scl... more Cholangiocarcinoma (CCA) results from the malignant transformation of cholangiocytes. Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are chronic diseases in which cholangiocytes are primarily damaged. Although PSC is an inflammatory condition predisposing to CCA, CCA is almost never found in the autoimmune context of PBC. Here, we hypothesized that PBC might favor CCA immunosurveillance. In preclinical murine models of cholangitis challenged with syngeneic CCA, PBC (but not PSC) reduced the frequency of CCA development and delayed tumor growth kinetics. This PBC-related effect appeared specific to CCA as it was not observed against other cancers, including hepatocellular carcinoma. The protective effect of PBC was relying on type 1 and type 2 T cell responses and, to a lesser extent, on B cells. Single-cell TCR/RNA sequencing revealed the existence of TCR clonotypes shared between the liver and CCA tumor of a PBC host. Altogether, these results evidence a...
Mice reconstituted with a human immune system and bearing human tumors represent a promising mode... more Mice reconstituted with a human immune system and bearing human tumors represent a promising model for developing novel cancer immunotherapy strategies. However, the nature of tumor infiltrating leukocytes in humanized mice and whether they can be mobilized to control tumor growth is currently unknown. Here, we used mass cytometry and multi parametric flow cytometry to characterize human leukocytes infiltrating a human breast cancer tumor model in CD34-reconstituted NOD.SCID.gc-null mice and compared it to breast cancer patient samples. We unambiguously detected human T cells, monocytes and plasmacytoid dendritic cells in the tumors of humanized mice. Importantly, activated/memory T cells and ICOS+ regulatory T cells were enriched in the tumor relative to the periphery both in humanized mice and in breast cancer patients. The presence of ICOS+ regulatory T cells in the tumor has been associated with poor survival in breast cancer patients. Administration of a neutralizing mAb to hum...
Proceedings of the National Academy of Sciences, 2007
Immunotherapy by using multimerized self-peptides has demonstrated a clear protective effect on e... more Immunotherapy by using multimerized self-peptides has demonstrated a clear protective effect on experimental models of autoimmune diseases. However, the mechanisms involved remain ill-defined. Here we have evaluated the therapeutic efficacy of multimerized self-peptides at the effector phase of autoimmune diabetes and examined their mechanisms of action. Diabetes was induced in rat insulin promoter-hemagglutinin (HA) mice expressing HA in pancreatic β-cells by adoptive transfer of HA 110–119 -specific T helper 1 cells. Complete protection was provided by low doses of the HA 4-mer consisting of four covalently linked linear HA 107–119 peptides. In vivo , the 4-mer appeared to act directly on the pathogenic HA-specific T helper 1 cells and indirectly by activation/recruitment of lymphocytes with regulatory properties so that mice became resistant to a second transfer of diabetogenic T cells. This effect was associated with a recruitment of Foxp3 + CD4 T cells around islets. Moreover, ...
Effective antibody responses are essential to generate protective humoral immunity. Different inf... more Effective antibody responses are essential to generate protective humoral immunity. Different inflammatory signals polarize T cells towards an appropriate effector phenotype during an infection or immunization. Th1 and Th2 cells have been associated with the polarization of humoral responses for several decades. However, it is now established that T follicular helper cells (Tfh) have a unique ability to access the B cell follicle and support the Germinal Centre (GCs) responses by providing help to B cells. We investigated the specialization of Tfh cells induced under type-1 and type-2 conditions. We first studied homogenous Tfh cell populations generated by adoptively transferred TCR-transgenic T cells in mice immunized with type-1 and type-2 adjuvants. Using a machine learning approach, we established a gene expression signature that discriminates Tfh cells polarized towards type-1 and type-2 response, defined as Tfh1 and Tfh2 cells. The Tfh1 and Tfh2 distinct signature was validat...
Increased number of circulating myeloid cells is a hallmark of most cancers, however it remains u... more Increased number of circulating myeloid cells is a hallmark of most cancers, however it remains unclear how primary tumors impact on myelopoiesis. Here we show that non-metastatic breast tumors remotely instruct the fate of long-term hematopoietic stem cell (HSCLT) in the bone marrow. We found that HSCLT from tumor bearing mice acquire a myeloid bias persisting upon primary and secondary HSCLT transfer in lethally-irradiated tumor-free animals. By imaging the bone marrow HSC niche, we found that the tumor-bearing status is associated with increased physical interactions between mesenchymal stem/stromal cells (MSC) and HSCLT. Moreover, ex vivo co-culture experiments demonstrate that MSC isolated from tumor-bearing mice increase myeloid differentiation of HSCLT isolated from tumor free mice. In summary, our data reveal that breast cancer remotely promotes myelopoiesis at the earliest stages of hematopoietic differentiation in the BM mesenchymal niche.
IL-2 reverses established type 1 diabetes in NOD mice by a local effect on pancreatic regulatory ... more IL-2 reverses established type 1 diabetes in NOD mice by a local effect on pancreatic regulatory T cells
Reactive oxygen species (ROS) are major contributors to neuropathology in both Multiple sclerosis... more Reactive oxygen species (ROS) are major contributors to neuropathology in both Multiple sclerosis and other neurodegenerative disorders. ROS are small molecules with unpaired electrons, making them highly reactive and their actions need to be tightly regulated. ROS can initiate oxidative degradation of poly unsaturated lipids in the cell membrane leading to lipid peroxidation. In this process other reactive compounds are generated, among which 4-hydroxynonenal (4-HNE) is one. 4-HNE is in itself neurotoxic and has been associated with neurodegenerative diseases and occurs in MS lesions. The most efficient defense against free 4-HNE is Glutathione-S-transferase 4 alpha (Gsta4), which ligates HNE to glutathione. We have studied the influence of allelic variation in Gsta4 in combination with its transgenic modified expression in two models of inflammation/neurodegeneration; controlled contusion traumatic brain injury (TBI) and experimental autoimmune encephalomyelitis (EAE). Susceptibility was compared between Dark Agouti (DA), a congenic rat strain on DA backgroundwith a small chromosome 8 fragment containing an expression quantitative trait locus for Gsta4 and a Gsta4 transgenic strain on DA background. We find that high Gsta4 mRNA and protein levels correlate with increased nerve cell survival in the TBI model as well as after intrathecal 4-HNE administration. Allelic variation in Gsta4 does not statistically significantly affect the EAE score over 50 days, although there is a trend of improvedEAE score in the higherGsta4 expressing congenic strain. At the moment these findings are being repeated in the Gsta4 transgenic strain. Our data stresses Gsta4 as a key player in acute and chronic nerve cell degenerating conditions.
Tumor-infiltrating CD8 + T cells progressively lose functionality and fail to reject tumors. The ... more Tumor-infiltrating CD8 + T cells progressively lose functionality and fail to reject tumors. The underlying mechanism and re-programing induced by checkpoint blockers are incompletely understood. We show here that genetic ablation or pharmacological inhibition of histone lysine methyltransferase Suv39h1 delays tumor growth and potentiates tumor rejection by anti-PD-1. In the absence of Suv39h1, anti-PD-1 induces alternative activation pathways allowing survival and differentiation of IFNγ and Granzyme B producing effector cells that express negative checkpoint molecules, but do not reach final exhaustion. Their transcriptional program correlates with that of melanoma patients responding to immune-checkpoint blockade and identifies the emergence of cytolytic-effector tumor-infiltrating lymphocytes as a biomarker of clinical response. Anti-PD-1 favors chromatin opening in loci linked to T-cell activation, memory and pluripotency, but in the absence of Suv39h1, cells acquire accessibil...
Macrophage infiltration is a hallmark of solid cancers, and overall macrophage infiltration corre... more Macrophage infiltration is a hallmark of solid cancers, and overall macrophage infiltration correlates with lower patient survival and resistance to therapy. Tumor-associated macrophages, however, are phenotypically and functionally heterogeneous. Specific subsets of tumor-associated macrophage might be endowed with distinct roles on cancer progression and antitumor immunity. Here, we identify a discrete population of FOLR2+ tissue-resident macrophages in healthy mammary gland and breast cancer primary tumors. FOLR2+ macrophages localize in perivascular areas in the tumor stroma, where they interact with CD8+ T cells. FOLR2+ macrophages efficiently prime effector CD8+ T cells ex vivo. The density of FOLR2+ macrophages in tumors positively correlates with better patient survival. This study highlights specific roles for tumor-associated macrophage subsets and paves the way for subset-targeted therapeutic interventions in macrophages-based cancer therapies.
Senescent T cells have been described during aging, chronic infections, and cancer; however, a co... more Senescent T cells have been described during aging, chronic infections, and cancer; however, a comprehensive study of the phenotype, function, and transcriptional program of this T cell population in breast cancer (BC) patients is missing. Compared to healthy donors (HDs), BC patients exhibit an accumulation of KLRG-1+CD57+ CD4+ and CD8+ T cells in peripheral blood. These T cells infiltrate tumors and tumor-draining lymph nodes. KLRG-1+CD57+ CD4+ and CD8+ T cells from BC patients and HDs exhibit features of senescence, and despite their inhibitory receptor expression, they produce more effector cytokines and exhibit higher expression of Perforin, Granzyme B, and CD107a than non-senescent subsets. When compared to blood counterparts, tumor-infiltrating senescent CD4+ T cells show similar surface phenotype but reduced cytokine production. Transcriptional profiling of senescent CD4+ T cells from the peripheral blood of BC patients reveals enrichment in genes associated with NK or CD8+-...
The invention relates to pharmaceutical compositions using a polypeptide comprising at least one ... more The invention relates to pharmaceutical compositions using a polypeptide comprising at least one CXXC motif, such as Giardia parasite's variable surface proteins (VSP) or a fragment thereof to raise by oral or mucosal vaccination an immune response against a heterologous selected antigen, such as tumor antigen, microbial antigen or other antigen.
Changes in the oral microbiome, particularly Fusobacterium nucleatum, are associated with oral sq... more Changes in the oral microbiome, particularly Fusobacterium nucleatum, are associated with oral squamous cell carcinoma (OSCC). F. nucleatum has been reported to modulate local immunity in cancers. We aimed to assess the association between intratumoral F. nucleatum and clinico-pathological features, relapse, and overall survival (OS) in two independent cohorts of patients with OSCC, and to explore the interplay with immune-related genes. We retrospectively analyzed tissue samples from a first cohort of 122 patients with head and neck squamous cell carcinoma, including 61 OSCC (cohort #1), and a second cohort of 90 additional OSCC (cohort #2). We then performed a sensitivity analysis on the merged cohort of OSCC patients (N = 151). F. nucleatum 16S rRNA gene sequences were quantified using real-time quantitative PCR. The presence of gram-negative bacteria and macrophages was confirmed by LPS and CD163 immunostainings, respectively. F. nucleatum positivity was associated with older ag...
Cholangiocarcinoma (CCA) results from the malignant transformation of cholangiocytes. Primary scl... more Cholangiocarcinoma (CCA) results from the malignant transformation of cholangiocytes. Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are chronic diseases in which cholangiocytes are primarily damaged. Although PSC is an inflammatory condition predisposing to CCA, CCA is almost never found in the autoimmune context of PBC. Here, we hypothesized that PBC might favor CCA immunosurveillance. In preclinical murine models of cholangitis challenged with syngeneic CCA, PBC (but not PSC) reduced the frequency of CCA development and delayed tumor growth kinetics. This PBC-related effect appeared specific to CCA as it was not observed against other cancers, including hepatocellular carcinoma. The protective effect of PBC was relying on type 1 and type 2 T cell responses and, to a lesser extent, on B cells. Single-cell TCR/RNA sequencing revealed the existence of TCR clonotypes shared between the liver and CCA tumor of a PBC host. Altogether, these results evidence a...
Mice reconstituted with a human immune system and bearing human tumors represent a promising mode... more Mice reconstituted with a human immune system and bearing human tumors represent a promising model for developing novel cancer immunotherapy strategies. However, the nature of tumor infiltrating leukocytes in humanized mice and whether they can be mobilized to control tumor growth is currently unknown. Here, we used mass cytometry and multi parametric flow cytometry to characterize human leukocytes infiltrating a human breast cancer tumor model in CD34-reconstituted NOD.SCID.gc-null mice and compared it to breast cancer patient samples. We unambiguously detected human T cells, monocytes and plasmacytoid dendritic cells in the tumors of humanized mice. Importantly, activated/memory T cells and ICOS+ regulatory T cells were enriched in the tumor relative to the periphery both in humanized mice and in breast cancer patients. The presence of ICOS+ regulatory T cells in the tumor has been associated with poor survival in breast cancer patients. Administration of a neutralizing mAb to hum...
Proceedings of the National Academy of Sciences, 2007
Immunotherapy by using multimerized self-peptides has demonstrated a clear protective effect on e... more Immunotherapy by using multimerized self-peptides has demonstrated a clear protective effect on experimental models of autoimmune diseases. However, the mechanisms involved remain ill-defined. Here we have evaluated the therapeutic efficacy of multimerized self-peptides at the effector phase of autoimmune diabetes and examined their mechanisms of action. Diabetes was induced in rat insulin promoter-hemagglutinin (HA) mice expressing HA in pancreatic β-cells by adoptive transfer of HA 110–119 -specific T helper 1 cells. Complete protection was provided by low doses of the HA 4-mer consisting of four covalently linked linear HA 107–119 peptides. In vivo , the 4-mer appeared to act directly on the pathogenic HA-specific T helper 1 cells and indirectly by activation/recruitment of lymphocytes with regulatory properties so that mice became resistant to a second transfer of diabetogenic T cells. This effect was associated with a recruitment of Foxp3 + CD4 T cells around islets. Moreover, ...
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Papers by Eliane Piaggio