Biomedical subjects

Pierre G Coulie

Publications and source records attributed to Pierre G Coulie.

At least 19 recordsLinked to original sources

PubMed2026

The phosphate exporter XPR1 promotes gasdermin D-independent mature IL-1β secretion.

Interleukin (IL)-1β is a leaderless inflammatory cytokine that is not secreted via the classical endoplasmic reticulum-Golgi pathway. Instead, m(ature) IL-1β secretion is classically associated with pyroptosis, a caspase-dependent inflammatory cell death mediated by gasdermin D (GSDMD) pore formation at the plasma membrane. However, human monocytes can secrete mIL-1β in the absence of cell death, and the contribution of GSDMD in this secretory pathway remains poorly defined. Here, we distinguished two pathways for mIL-1β secretion in living human monocytic cells : a rapid, GSDMD-dependent pathway and a slower, GSDMD-independent pathway. Using a genome-wide CRISPR-Cas9 screen, we identified XPR1 (Xenotropic and Polytropic retrovirus Receptor 1) as a regulator of the GSDMD-independent pathway. XPR1, the only phosphate exporter identified in metazoans, has not previously been implicated in cytokine secretion. Genetic invalidation of XPR1 in GSDMD-deficient monocytic cells markedly reduced IL-1β secretion. We further showed that this regulatory function requires XPR1 surface expression and phosphate export activity. These findings reveal an unexpected link between phosphate homeostasis and non-lytic mIL-1β secretion, opening new opportunities to modulate IL-1β-driven inflammatory diseases.

IL-1β secretion↗

PubMed2007

Cancer-germline gene expression in pediatric solid tumors using quantitative real-time PCR.

Cancer-germline genes (CGGs) code for immunogenic antigens that are present on various human tumors but not on normal tissues. The importance of CGGs in cancer immunotherapy has led to detailed studies of their expression in a range of human tumors. We measured the levels of expression of 12 CGGs in various pediatric solid tumors to identify targets for therapeutic cancer vaccines. Quantitative real-time PCR (qPCR) was used to measure the expression of 8 MAGE genes and of genes LAGE-2/NY-ESO-1 and GAGE-1, 2, 8 in 9 osteosarcomas, 10 neuroblastomas, 12 rhabdomyosarcomas and 18 Ewing's sarcomas. Nine tumors were also examined by immunohistochemistry with monoclonal antibodies specific for the MAGE-A1, MAGE-A4 and NY-ESO-1 proteins. All osteosarcoma and 80% of neuroblastoma samples expressed several CGGs at high levels. Six of 12 rhabdomyosarcomas and 11 of 18 Ewing's sarcomas expressed at least one CGG. Immunohistochemistry data correlated well with qPCR results and showed a homogeneous protein distribution pattern in most positive tumors. No correlation was found between the levels of CGG expression in the tumors and clinicopathological parameters of the patients. Pediatric solid tumors express several CGGs, which encode antigens that could be targeted in therapeutic vaccination trials. Several CGGs of the MAGE, GAGE and LAGE families are coexpressed in a large proportion of osteosarcoma and neuroblastoma samples. Some rhabdomyosarcomas express several of these genes at high levels. Ewing's sarcomas have an overall low CGG expression.

Adolescent↗

PubMed2006

An antigen produced by splicing of noncontiguous peptides in the reverse order.

CD8-positive T lymphocytes recognize peptides that are usually derived from the degradation of cellular proteins and are presented by class I molecules of the major histocompatibility complex. Here we describe a human minor histocompatibility antigen created by a polymorphism in the SP110 nuclear phosphoprotein gene. The antigenic peptide comprises two noncontiguous SP110 peptide segments spliced together in reverse order to that in which they occur in the predicted SP110 protein. The antigenic peptide could be produced in vitro by incubation of precursor peptides with highly purified 20S proteasomes. Cutting and splicing probably occur within the proteasome by transpeptidation.

Alleles↗

PubMed2006

Lack of tumor recognition by cytolytic T lymphocyte clones recognizing peptide 195-203 encoded by gene MAGE-A3 and presented by HLA-A24 molecules.

Gene MAGE-A3 encodes tumor-specific antigenic peptides recognized by T cells on many tumors. MAGE-A3 peptides presented by HLA class I molecules have been identified using CD8 lymphocytes stimulated with cells that either expressed gene MAGE-A3 or were pulsed with candidate peptides. One antigen identified with the latter method is peptide MAGE-A3(195-203) IMPKAGLLI, presented by HLA-A24 molecules. It has been used to vaccinate advanced cancer patients. Here, we have used HLA/peptide tetramers to detect T cells recognizing this peptide. Their frequency was estimated to be 2 x 10(-8) of the blood CD8 cells in non-cancerous HLA-A24(+) individuals, which is tenfold lower than the reported frequencies of T cells against other MAGE peptides. In the blood of a patient vaccinated with MAGE-A3, the estimated frequency was 5 x 10(-7). Anti-MAGE-3.A24 cytolytic T cell clones were derived, that lysed peptide-pulsed cells with half-maximal effect at the low concentration of 500 pM. However, these CTL did not recognize a panel of HLA-A24(+) tumor cells that expressed MAGE-A3 at levels similar to those found in HLA-A1(+) tumor cells recognized by anti-MAGE-3.A1 CTLs. Furthermore, 293-EBNA cells transfected with MAGE-A3 and HLA-A24 constructs were hardly recognized by the anti-MAGE-3.A24 CTL clones. These results suggest that peptide MAGE-A3(195-203) is poorly processed and is not an appropriate target for cancer immunotherapy.

Antigen Presentation↗

PubMed2006

A point mutation in the NFYC gene generates an antigenic peptide recognized by autologous cytolytic T lymphocytes on a human squamous cell lung carcinoma.

We have identified an antigen recognized by cytolytic T lymphocytes (CTL) on the autologous tumor cells of a nonsmall cell lung cancer patient. The antigenic peptide, presented by HLA-B*5201 molecules, was encoded by a mutated sequence in the gene coding for the C subunit of transcription factor NF-Y. The mutation was present in the tumor sample from which the cell line was derived, and appeared to be unique to the tumor of this patient. In a lymph node draining the tumor, precursors of CTL recognizing the autologous tumor cells were detected at a frequency of about 1/30,000 of the CD8 cells, and 85% of them recognized the mutated NF-YC peptide, suggesting that the patient mounted a T cell response against this antigen. These results strengthened the notion that unique tumor-specific antigens are highly represented not only in melanoma but also in other types of tumors, like nonsmall cell lung cancer.

Antigens, Neoplasm↗

PubMed2006

Human T cell responses against melanoma.

Many antigens recognized by autologous T lymphocytes have been identified on human melanoma. Melanoma patients usually mount a spontaneous T cell response against their tumor. But at some point, the responder T cells become ineffective, probably because of a local immunosuppressive process occurring at the tumor sites. Therapeutic vaccination of metastatic melanoma patients with these antigens is followed by tumor regressions only in a small minority of the patients. The T cell responses to the vaccines show correlation with the tumor regressions. The local immunosuppression may be the cause of the lack of vaccination effectiveness that is observed in most patients. In patients who do respond to the vaccine, the antivaccine T cells probably succeed in reversing focally this immunosuppression and trigger a broad activation of other antitumor T cells, which proceed to destroy the tumor.

Amino Acid Sequence↗

PubMed2005

Analysis of a rare melanoma patient with a spontaneous CTL response to a MAGE-A3 peptide presented by HLA-A1.

We describe an HLA-A1 melanoma patient who has mounted a spontaneous cytolytic T cell (CTL) response against an antigenic peptide encoded by gene MAGE-A3 and presented by HLA-A1. The frequency of anti-MAGE-3.A1 CTLp was 5 x 10(-7) of the blood CD8 cells, with a dominant clonotype which was present in six out of seven independent anti-MAGE-3.A1 CTL clones. After vaccination with a recombinant poxvirus coding for the MAGE-3.A1 antigen, the blood frequency of anti-MAGE-3.A1 CTLp increased tenfold. Twenty-two independent CTL clones were derived. Surprisingly, only one of them corresponded to the dominant clonotype present before vaccination. Two new clonotypes were repeated 12 and 7 times, respectively. Our interpretation of these results is that the spontaneous anti-MAGE-3.A1 CTL response pre-existing to vaccination was polyclonal, and that the vaccine restimulated only some of these clones. To estimate the incidence of spontaneous anti-MAGE-3.A1 CTL responses in melanoma patients with a tumor expressing gene MAGE-A3, we measured the blood frequency of anti-MAGE-3.A1 T cells in 45 patients, and found only two clear responses.

Aged↗

PubMed2005

Tumoral and immunologic response after vaccination of melanoma patients with an ALVAC virus encoding MAGE antigens recognized by T cells.

PURPOSE: To evaluate the toxicity, antitumoral effectiveness, and immunogenicity of repeated vaccinations with ALVAC miniMAGE-1/3, a recombinant canarypox virus containing a minigene encoding antigenic peptides MAGE-3(168-176) and MAGE-1(161-169), which are presented by HLA-A1 and B35 on tumor cells and can be recognized by cytolytic T lymphocytes (CTLs). MATERIALS AND METHODS: The vaccination schedule comprised four sequential injections of the recombinant virus, followed by three booster vaccinations with the MAGE-3(168-176) and MAGE-1(161-169) peptides. The vaccines were administered, both intradermally and subcutaneously, at 3-week intervals. RESULTS: Forty patients with advanced cancer were treated, including 37 melanoma patients. The vaccines were generally well tolerated with moderate adverse events, consisting mainly of transient inflammatory reactions at the virus injection sites. Among the 30 melanoma patients assessable for tumor response, a partial response was observed in one patient, and disease stabilization in two others. The remaining patients had progressive disease. Among the patients with stable or progressive disease, five showed evidence of tumor regression. A CTL response against the MAGE-3 vaccine antigen was detected in three of four patients with tumor regression, and in only one of 11 patients without regression. CONCLUSION: Repeated vaccination with ALVAC miniMAGE-1/3 is associated with tumor regression and with a detectable CTL response in a minority of melanoma patients. There is a significant correlation between tumor regression and CTL response. The contribution of vaccine-induced CTL in the tumor regression process is discussed in view of the immunologic events that could be analyzed in detail in one patient.

Adult↗

PubMed2005

Contrasting frequencies of antitumor and anti-vaccine T cells in metastases of a melanoma patient vaccinated with a MAGE tumor antigen.

Melanoma patients have high frequencies of T cells directed against antigens of their tumor. The frequency of these antitumor T cells in the blood is usually well above that of the anti-vaccine T cells observed after vaccination with tumor antigens. In a patient vaccinated with a MAGE-3 antigen presented by HLA-A1, we measured the frequencies of anti-vaccine and antitumor T cells in several metastases to evaluate their respective potential contribution to tumor rejection. The frequency of anti-MAGE-3.A1 T cells was 1.5 x 10(-5) of CD8 T cells in an invaded lymph node, sixfold higher than in the blood. An antitumor cytotoxic T lymphocyte (CTL) recognizing a MAGE-C2 antigen showed a much higher enrichment with a frequency of approximately 10%, 1,000 times higher than its blood frequency. Several other antitumor T clonotypes had frequencies >1%. Similar findings were made on a regressing cutaneous metastasis. Thus, antitumor T cells were approximately 10,000 times more frequent than anti-vaccine T cells inside metastases, representing the majority of T cells present there. This suggests that the anti-vaccine CTLs are not the effectors that kill the bulk of the tumor cells, but that their interaction with the tumor generates conditions enabling the stimulation of large numbers of antitumor CTLs that proceed to destroy the tumor cells. Naive T cells appear to be stimulated in the course of this process as new antitumor clonotypes arise after vaccination.

Antigens, Neoplasm↗

PubMed2005

High frequency of antitumor T cells in the blood of melanoma patients before and after vaccination with tumor antigens.

After vaccination of melanoma patients with MAGE antigens, we observed that even in the few patients showing tumor regression, the frequency of anti-vaccine T cells in the blood was often either undetectable or <10(-5) of CD8 T cells. This frequency being arguably too low for these cells to be sole effectors of rejection, we reexamined the contribution of T cells recognizing other tumor antigens. The presence of such antitumor T cells in melanoma patients has been widely reported. To begin assessing their contribution to vaccine-induced rejection, we evaluated their blood frequency in five vaccinated patients. The antitumor cytotoxic T lymphocyte (CTL) precursors ranged from 10(-4) to 3 x 10(-3), which is 10-10,000 times higher than the anti-vaccine CTL in the same patient. High frequencies were also observed before vaccination. In a patient showing nearly complete regression after vaccination with a MAGE-3 antigen, we observed a remarkably focused antitumoral response. A majority of CTL precursors (CTLp's) recognized antigens encoded by MAGE-C2, another cancer-germline gene. Others recognized gp100 antigens. CTLp's recognizing MAGE-C2 and gp100 antigens were already present before vaccination, but new clonotypes appeared afterwards. These results suggest that a spontaneous antitumor T cell response, which has become ineffective, can be reawakened by vaccination and contribute to tumor rejection. This notion is reinforced by the frequencies of anti-vaccine and antitumor CTLs observed inside metastases, as presented by Lurquin et al. (Lurquin, C., B. Lethe, V. Corbiere, I. Theate, N. van Baren, P.G. Coulie, and T. Boon. 2004. J. Exp. Med. 201:249-257).

Antigens, Neoplasm↗

PubMed2005

Human tumor-specific T lymphocytes: does function matter more than number?

In recent years, several clinical trials have involved the vaccination of cancer patients with tumor-specific antigens that are recognized by T lymphocytes. Anti-vaccine T-cell responses in these patients have been monitored on the assumption that their magnitude would correlate with clinical efficacy. Although analysis of these data show that such a correlation is emerging, detailed analyses of the few patients who benefit clinically from the vaccinations suggest that the function of the anti-vaccine T cells might be more important than their number. Recent studies show that in cancer patients numerous tumor-specific T cells appear to be quiescent in the presence of the tumor. Understanding how an efficient vaccine interferes with this coexistence is one of the current challenges of cancer immunotherapy.

Animals↗

PubMed2004

A major histocompatibility complex-peptide-restricted antibody and t cell receptor molecules recognize their target by distinct binding modes: crystal structure of human leukocyte antigen (HLA)-A1-MAGE-A1 in complex with FAB-HYB3.

Antibodies with T cell receptor-like specificity possess a considerable diagnostic and therapeutic potential, but the structural basis of the interaction between an antibody and an histocompatibility antigen has so far not been determined. We present here the crystal structure (at 2.15 A resolution) of the recombinant, affinity-matured human antibody fragment Fab-Hyb3 bound to the tumor-associated human leukocyte antigen (HLA)/peptide complex HLA-A1.MAGE-A1. Fab-Hyb3 employs a diagonal docking mode resembling that of T cell receptors. However, other than these natural ligands, the antibody uses only four of its six complementarity-determining regions for direct interactions with the target. It recognizes the C-terminal half of the MAGE-A1 peptide, the HLA-A1 alpha1-helix, and N-terminal residues of the alpha2-helix, accompanied by a large tilting angle between the two types of molecules within the complex. Interestingly, only a single hydrogen bond between a peptide side chain and Fab-Hyb3 contributes to the interaction, but large buried surface areas with pronounced shape complementarity assure high affinity and specificity for MAGE-A1. The HLA-A1.MAGE-A1.antibody structure is discussed in comparison with those of natural ligands recognizing HLA.peptide complexes.

Amino Acid Sequence↗

PubMed2004

Two new tumor-specific antigenic peptides encoded by gene MAGE-C2 and presented to cytolytic T lymphocytes by HLA-A2.

We have identified 2 antigens recognized by several melanoma-specific cytolytic T lymphocyte clones isolated from a melanoma patient with a clinical history of tumor regression after immunotherapy. Both antigens are presented by HLA-A2 and encoded by gene MAGE-C2, a cancer-germline gene shown previously to be silent in normal somatic tissues and expressed in 40% of melanomas and in other tumor types. One antigen corresponds to peptide ALKDVEERV(336-344), whereas the other corresponds to peptide LLFGLALIEV(191-200). The CTL clones recognizing these 2 peptides also recognized allogeneic tumor cell lines expressing MAGE-C2 and HLA-A2. These 2 new peptides are the first known MAGE-C antigens and represent promising targets for cancer immunotherapy.

Amino Acid Sequence↗

PubMed2003

Polyclonal CTL responses observed in melanoma patients vaccinated with dendritic cells pulsed with a MAGE-3.A1 peptide.

Vaccination with mature, monocyte-derived dendritic cells (DC) pulsed with the MAGE-3(168-176) peptide, which is presented by HLA-A1, has been reported to induce tumor regressions and CTL in some advanced stage IV melanoma patients. We present here a precise evaluation of the level of some of these anti-MAGE-3.A1 CTL responses and an analysis of their clonal diversity. Blood lymphocytes were stimulated with the MAGE-3.A1 peptide under limiting dilution conditions and assayed with an A1/MAGE-3 tetramer. This was followed by the cloning of the tetramer-positive cells and by TCR sequence analysis of the CTL clones that lysed targets expressing MAGE-3.A1. We also used direct ex vivo tetramer staining of CD8 cells, sorting, and cloning of the positive cells. In three patients who showed regression of some of their metastases after vaccination, CTL responses were observed with frequencies ranging from 7 x 10(-6) to 9 x 10(-4) of CD8(+) blood T lymphocytes, representing an increase of 20- to 400-fold of the frequencies found before immunization. A fourth patient showed neither tumor regression nor an anti-MAGE-3.A1 CTL response. In each of the responses, several CTL clones were amplified. This polyclonality contrasts with the monoclonality of the CTL responses observed in patients vaccinated with MAGE-3.A1 peptide or with an ALVAC recombinant virus coding for this antigenic peptide.

Antigens, Neoplasm↗

PubMed2003

Monoclonal anti-MAGE-3 CTL responses in melanoma patients displaying tumor regression after vaccination with a recombinant canarypox virus.

We have analyzed the T cell responses of HLA-A1 metastatic melanoma patients with detectable disease, following vaccination with a recombinant ALVAC virus, which bears short MAGE-1 and MAGE-3 sequences coding for antigenic peptides presented by HLA-A1. To evaluate the anti-MAGE CTL responses, we resorted to antigenic stimulation of blood lymphocytes under limiting dilution conditions, followed by tetramer analysis and cloning of the tetramer-positive cells. The clones were tested for their specific lytic ability and their TCR sequences were obtained. Four patients who showed tumor regression were analyzed, and an anti-MAGE-3.A1 CTL response was observed in three of these patients. Postvaccination frequencies of anti-MAGE-3.A1 CTL were 3 x 10(-6), 3 x 10(-3), and 3 x 10(-7) of the blood CD8 T cells, respectively. These three responses were monoclonal. No anti-MAGE-1.A1 CTL response was observed. These results indicate that, like peptide immunization, ALVAC immunization produces monoclonal responses. They also suggest that low-level antivaccine CTL responses can initiate a tumor regression process. Taken together, our analysis of anti-MAGE-3.A1 T cell responses following peptide or ALVAC vaccination shows a degree of correlation between CTL response and tumor regression, but firm conclusions will require larger numbers.

Antigens, Neoplasm↗

PubMed2003

Prevalent role of TCR alpha-chain in the selection of the preimmune repertoire specific for a human tumor-associated self-antigen.

The specificity of recognition of pMHC complexes by T lymphocytes is determined by the V regions of the TCR alpha- and beta-chains. Recent experimental evidence has suggested that Ag-specific TCR repertoires may exhibit a more V alpha- than V beta-restricted usage. Whether V alpha usage is narrowed during immune responses to Ag or if, on the contrary, restricted V alpha usage is already defined at the early stages of TCR repertoire selection, however, has remained unexplored. Here, we analyzed V and CDR3 TCR regions of single circulating naive T cells specifically detected ex vivo and isolated with HLA-A2/melan-A peptide multimers. Similarly to what was previously observed for melan-A-specific Ag-experienced T cells, we found a relatively wide V beta usage, but a preferential V alpha 2.1 usage. Restricted V alpha 2.1 usage was also found among single CD8(+) A2/melan-A multimer(+) thymocytes, indicating that V alpha-restricted selection takes place in the thymus. V alpha 2.1 usage, however, was independent from functional avidity of Ag recognition. Thus, interaction of the pMHC complex with selected V alpha-chains contributes to set the broad Ag specificity, as underlined by preferential binding of A2/melan-A multimers to V alpha 2.1-bearing TCRs, whereas functional outcomes result from the sum of these with other interactions between pMHC complex and TCR.

Amino Acid Sequence↗

PubMed2003

T-cell responses of vaccinated cancer patients.

Following vaccination with defined tumor antigens that are recognized by T cells, a small proportion of cancer patients display tumor regressions. Several reports describe anti-vaccine T-cell responses, evaluated with a variety of methods, for example, by assessing T-cell function or expression of specific TCR. However, a correlation between these T-cell responses and the tumor regressions has not yet been established. It appears that some patients display tumor regression with an unexpectedly low frequency of anti-vaccine T cells.

Antigens, Neoplasm↗

PubMed2002

A human endogenous retroviral sequence encoding an antigen recognized on melanoma by cytolytic T lymphocytes.

We have identified a gene encoding an antigen recognized by cytolytic T lymphocytes on the autologous tumor cells of a melanoma patient, AVL3. The gene shows homologies with members of the HERV-K family of human endogenous retroviruses, and it was provisionally named HERV-K-MEL. It contains many mutations that disrupt the open reading frames coding for all of the viral proteins. The HERV-K-MEL gene is not expressed in normal tissues with the exception of testis and some skin samples. It is expressed in most samples of cutaneous and ocular melanoma. It is also expressed in a majority of naevi and in a minority of carcinomas and sarcomas. The antigenic peptide, presented by HLA-A2 molecules, is encoded by a very short open reading frame present in the env region of a spliced HERV-K-MEL transcript. Anti-HERV.A2 CTLp could not be detected in the blood of three individuals without cancer but were present at a frequency of 3 x 10(-5) among blood CD8 T cells in patient AVL3 and 6 x 10(-7) in another HLA-A2 melanoma patient whose tumor expressed HERV-K-MEL. Anti-HERV.A2 CTL clones derived from each patient lysed melanoma cells. Analysis of T-cell receptor beta chain sequences indicated that the anti-HERV.A2 CTL population was oligoclonal in patient AVL3 and probably monoclonal in the other patient. These results suggest that HERV-K-MEL is a source of antigens that are targeted by CTLs in melanoma patients and could therefore be used for vaccination.

Amino Acid Sequence↗