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M Dupuis

Publications and source records attributed to M Dupuis.

At least 19 recordsLinked to original sources
PubMed1999

Distribution of adjuvant MF59 and antigen gD2 after intramuscular injection in mice.

MF59, which is an adjuvant approved for human use, typically elicits higher antibody titers than alum when used in combination with a variety of recombinant and natural subunit antigens. The mechanisms responsible for the adjuvant action of MF59 are not fully understood. In particular, little is known about the in vivo distribution of MF59 and of antigen after intramuscular (i.m.) injection. The goal of the present study was to determine the distribution of MF59 injected with soluble antigen gD2 from type 2 herpes simplex virus (HSV) and to compare the distribution of gD2 injected with or without MF59. At 4 h, 36% of the injected dose of labeled MF59 was in the quadriceps muscle and about 50% was in the inguinal fat surrounding the muscle. Half of the initial amount of labeled MF59 in muscle was detected 42 h after injection. The amount of labeled MF59 in the draining lymph nodes was maximal 2 d after injection, which represented 0.1-0.3% of the injected dose. At 4 h, 12% of the injected dose of labeled gD2 was found in the muscle. The presence of MF59 did not significantly modify the distribution of gD2. The results indicate that MF59 and gD2 distribute and are cleared independently after i.m. injection. Importantly, MF59 is unlikely to have a repository effect, whereby it slowly releases the antigen.

Adjuvants, Immunologic↗
PubMed1999

Collagenase 3 production by human osteoarthritic chondrocytes in response to growth factors and cytokines is a function of the physiologic state of the cells.

OBJECTIVE: We investigated the response of human osteoarthritic (OA) chondrocytes, in terms of collagenase 3 production, to growth factors and cytokines involved in the anabolism and catabolism of articular cartilage, and explored the major signaling pathways leading to its up-regulation. METHODS: Human OA chondrocytes were treated with the following factors: the proinflammatory cytokine interleukin-1beta (IL-1beta), the growth factors basic fibroblast growth factor (bFGF), platelet-derived growth factor BB (PDGF-BB), parathyroid hormone (PTH), insulin-like growth factor 1 (IGF-1), transforming growth factor gamma1 (TGFbeta1), and TGFbeta2, the protein kinase (PK) activator antagonists for PKC, PKA, and PKG pathways, and phospholipase A2 and tyrosine kinases, as well as the antiinflammatory cytokines IL-4, IL-10, and IL-13. Collagenase 3 expression and synthesis were determined. Comparison was made with collagenase 1. RESULTS: The human OA chondrocyte population could be divided into 2 categories: the L chondrocytes, showing low collagenase 3 basal synthesis levels and high sensitivity to IL-1beta stimulation; and the H chondrocytes, high collagenase 3 basal synthesis levels and low IL-1beta inducibility. In L chondrocytes, all growth factors stimulated collagenase 3 production. In H chondrocytes, PTH, IGF-1, and TGFbeta had little or no impact; bFGF slightly stimulated it and PDGF-BB showed the same pattern as in the L chondrocytes. The effects of all growth factors, except TGFbeta, on collagenase 1 synthesis followed those of collagenase 3, albeit to a higher degree. Interestingly and unlike collagenase 3, the effects of TGFbeta on collagenase 1 could not be related to the state of the cells, but rather, depended on the isoform. Indeed, TGFbeta2 did not induce collagenase 1 synthesis, whereas TGFbeta1 stimulated it. Among the PK activators tested, phorbol myristate acetate was the strongest inducer, suggesting a major involvement of the PKC pathway. IL-13 inhibited collagenase 3 production, IL-4 had little effect, and IL-10 had none. CONCLUSION: This study shows that collagenase 3 production in human OA chondrocytes depends on the physiologic state of the cell. TGFbeta might be responsible for the change in cells from the L to the H state. Importantly, our in vitro data implicate TGFbeta2 as a possible in vivo agent capable of specifically triggering collagenase 3 production over that of collagenase 1 in OA cartilage.

Aged↗
PubMed1999

In vivo transfer of interleukin-1 receptor antagonist gene in osteoarthritic rabbit knee joints: prevention of osteoarthritis progression.

The goal of this study was to determine the efficacy of local IL-1Ra gene therapy by intra-articular plasmid injections on structural changes in the meniscectomy rabbit model of osteoarthritis. A partial meniscectomy of the right knee was performed on the rabbits through a medial parapatellar incision. The rabbits were then divided into four experimental groups. Group 1 received no treatment. Group 2 received three consecutive intra-articular injections at 24-hour intervals of 0.9% saline containing a lipid, gammaAP-DLRIE/DOPE, and a DNA plasmid, VR1012. Group 3 received three consecutive injections of saline containing 1000 microg of canine IL-1Ra plasmid and lipid. The injections were given starting 4 weeks post-surgery. Rabbits from Group 1 were killed 4 weeks post-surgery, and all other rabbits 8 weeks post-surgery. The severity of macroscopic and microscopic changes on cartilage on the medial and femoral condyles and tibial plateaus and synovium were graded separately. Specimens were also processed for immunohistochemical staining using a rabbit polyclonal antibody against canine IL-1Ra. The level of canine IL-1Ra in synovial fluid was determined using enzyme-linked immunosorbent assay. The presence of the DNA plasmid in the synovium was tested by polymerase chain reaction. A significant reduction in the width of osteophytes and size of macroscopic lesions (P < 0.04) was observed, and was dependent on the amount of IL-1Ra plasmid injected. A significant reduction was also noted in the severity of histologic cartilage lesions (P < 0.01) in the group that received the highest dosage (1000 microg) of IL-1Ra plasmid. IL-1Ra was detected in synovial fluid by enzyme-linked immunosorbent assay and by immunohistochemical staining in the synovium and cartilage of rabbits that received injections containing the IL-1Ra plasmid. Polymerase chain reaction analysis of synovial DNA revealed the presence of the cloned cDNA dog IL-1Ra up to 4 weeks after the first intra-articular injection. This study demonstrates that direct in vivo transfer of the IL-1Ra gene into osteoarthritis knee cells using intra-articular injections of a plasmid vector and lipids can significantly reduce the progression of experimental osteoarthritis. This avenue may therefore represent a promising future treatment for osteoarthritis.

Animals↗
PubMed1999

Broad, intense anti-human immunodeficiency virus (HIV) ex vivo CD8(+) responses in HIV type 1-infected patients: comparison with anti-Epstein-Barr virus responses and changes during antiretroviral therapy.

The ex vivo antiviral CD8(+) repertoires of 34 human immunodeficiency virus (HIV)-seropositive patients with various CD4(+) T-cell counts and virus loads were analyzed by gamma interferon enzyme-linked immunospot assay, using peptides derived from HIV type 1 and Epstein-Barr virus (EBV). Most patients recognized many HIV peptides, with markedly high frequencies, in association with all the HLA class I molecules tested. We found no correlation between the intensity of anti-HIV CD8(+) responses and the CD4(+) counts or virus load. In contrast, the polyclonality of anti-HIV CD8(+) responses was positively correlated with the CD4(+) counts. The anti-EBV responses were significantly less intense than the anti-HIV responses and were positively correlated with the CD4(+) counts. Longitudinal follow-up of several patients revealed the remarkable stability of the anti-HIV and anti-EBV CD8(+) responses in two patients with stable CD4(+) counts, while both antiviral responses decreased in two patients with obvious progression toward disease. Last, highly active antiretroviral therapy induced marked decreases in the number of anti-HIV CD8(+) T cells, while the anti-EBV responses increased. These findings emphasize the magnitude of the ex vivo HIV-specific CD8(+) responses at all stages of HIV infection and suggest that the CD8(+) hyperlymphocytosis commonly observed in HIV infection is driven mainly by virus replication, through intense, continuous activation of HIV-specific CD8(+) T cells until ultimate progression toward disease. Nevertheless, highly polyclonal anti-HIV CD8(+) responses may be associated with a better clinical status. Our data also suggest that a decrease of anti-EBV CD8(+) responses may occur with depletion of CD4(+) T cells, but this could be restored by highly active antiretroviral treatment.

Antiviral Agents↗
PubMed1999

Tissue macrophages associated with angiogenesis in chronic airway inflammation in rats.

Angiogenesis is a feature of chronic inflammation produced by Mycoplasma pulmonis infection of the respiratory tract. The mechanism of this angiogenesis is unknown, but cellular growth factors and matrix remodeling proteases produced by inflammatory cells are likely to be involved. The goal of this study was to determine the relationship between changes in the number, shape, and distribution of ED2-immunoreactive macrophages and the development of angiogenesis in the tracheal mucosa of Wistar rats after M. pulmonis infection. In pathogen-free rats, ED2-positive cells were scattered in the airway mucosa (261 +/- 42 cells/mm2 of surface, mean +/- SE). Most cells were irregularly shaped and had moderate ED2 immunoreactivity. No lymphoid tissue was present. The number of ED2-positive cells increased rapidly after infection, was 120% above baseline at 1 wk, and remained significantly increased throughout the 4-wk study (P < 0.05). Angiogenesis was first detected at 2 wk, and at 3 wk the vessel length density was nearly 8-fold the pathogen-free value. At 3 and 4 wk, focal sites of angiogenesis coincided with discrete clusters of round, strongly immunoreactive ED2-positive cells (1,340 +/- 124 cells/mm2) in polyp-like collections of mucosal lymphoid tissue. The close association of distinctive ED2-positive cells with angiogenic blood vessels suggests a relationship between a subset of tissue macrophages and the angiogenesis associated with M. pulmonis infection. The time course of the changes indicates that the initial influx of ED2-positive macrophages precedes the angiogenesis, and the rounding of the cells parallels the growth of new vessels.

Animals↗
PubMed1999

Weak anti-HIV CD8(+) T-cell effector activity in HIV primary infection.

HIV-specific CD8(+) T cells play a major role in the control of virus during HIV primary infection (PI) but do not completely prevent viral replication. We used IFN-gamma enzyme-linked immunospot assay and intracellular staining to characterize the ex vivo CD8(+) T-cell responses to a large variety of HIV epitopic peptides in 24 subjects with early HIV PI. We observed HIV-specific responses in 71% of subjects. Gag and Nef peptides were more frequently recognized than Env and Pol peptides. The number of peptides recognized was low (median 2, range 0-6). In contrast, a much broader response was observed in 30 asymptomatic subjects with chronic infection: all were responders with a median of 5 peptides recognized (range 1-13). The frequency of HIV-specific CD8(+) T cells among PBMC for a given peptide was of the same order of magnitude in both groups. The proportion of HIV-specific CD8(+)CD28(-) terminally differentiated T cells was much lower in PI than at the chronic stage of infection. The weakness of the immune response during HIV PI could partially account for the failure to control HIV. These findings have potential importance for defining immunotherapeutic strategies and establishing the goals for effective vaccination.

Adult↗
PubMed1999

Contact dermatitis II. Clinical aspects and diagnosis.

Contact dermatitis (CD) is an altered state of skin reactivity induced by exposure to an external agent. "Eczema" and "dermatitis" are often used synonymously to denote a polymorphic pattern of inflammation of the skin characterized, at least in its acute phase, by erythema, vesiculation and pruritus. Substances that induce CD after single or multiple exposures may be irritant or allergic in nature. The clinical presentation may vary depending on the identity of the triggering agent and the reactivity of the subject, but in all cases the lesions are primarily confined to the site of contact. According to the mechanism of elicitation, the following types of contact reactions may be distinguished: (1) allergic contact dermatitis (ACD); (2) irritant contact dermatitis (ICD); (3) phototoxic and photoallergic contact dermatitis, and (4) immediate type contact reactions. The present review will focus on allergic contact dermatitis. ACD is the clinical presentation of contact sensitivity in humans. The pathophysiology of the contact sensitivity reaction has been reviewed in a preceding issue of this journal [1].

Dermatitis, Allergic Contact↗
PubMed1999

[A case of a aggressive giant-cell tumor with multiple bone metastases].

PURPOSE OF THE STUDY: Giant-cell tumor are known for local recurrence. Metastases are rare (2 p. 100), and generally located in the lung. We present a case with multiple bone metastases and rapid course. MATERIAL, METHODS AND RESULTS: A 45-year-old man presented a 5 cm giant-cell tumor of his right distal tibia and two other localisation in the fifth and sixth cervical vertebral bodies. He underwent a resection of the distal tibia and reconstruction with a controlateral free vascularized fibula. The bodies of the fifth and sixth cervical vertebral were resected and replaced by an iliac crest graft. Other localisations appeared in iliac right crest, in the posterior wall of the cotyle and in the second, third and fourth cervical vertebral bodies. Chemotherapy was administered and clinical signs regressed but eight months later the patient presented a recurrence of his tumor in the distal tibia with new localisation in the left fifth rib, in the right clavicle, in the frontal bone, in right ischio-pubal branch and in the right proximal femur. A new chemotherapy was performed but had little effect and probably hasved dubic death 13 month after the first symptom. DISCUSSION: The present observation is characterised by the large number of localisations (13; the highest number found in the literature was 11 localisations) and by the rapidity of the clinical course. Low grade giant-cell tumors generally give benign metastase with a course lasting several years. The chemotherapy helpt us to slow the progression of the lesions but was unable to prevent the development of new localisation and the recurrence in the distal tibia. More over, its toxicity could have caused the death of the patient. CONCLUSION: We present the case of one patient who presented a giant-cell tumor with unusual presentation: multiple bony metastases with rapidly fatal outcome.

Antineoplastic Agents↗
PubMed1998

Role of preimmunization virus sequences in cellular immunity in HIV-infected patients during HIV type 1 MN recombinant gp160 immunization.

The effect of patient preimmunization virus sequences on CTL responses during gp160 immunization were studied. Ten HLA-A2+, HIV+ asymptomatic patients with CD4+ T cells >500/mm3 were given two courses of HIV-1 MN rgp160 vaccine over a 2-year period. Envelope epitope-specific CTL responses, using PBMCs, were measured against peptide-coated autologous B lymphoblastoid cell lines. Optimum CTL epitopes were determined by HLA-A2-binding affinity of 9- to 10-mer peptides containing the HLA-A2.1-binding motif. Ten of the high- or intermediate-binding peptides were conserved among >50% of reported clade B HIV strains. These peptide-specific CTL activities and the patient virus sequences in peptide-coding regions were monitored. Six patients showed envelope peptide-specific CTL responses, which correlated with the presence of whole envelope antigen-specific CTL responses. Five of these patients, who showed responses to epitopes in the gp41 region (aa 814-824), had preimmunization virus similar to the vaccine sequence in this region. Three patients who did not show these epitope-specific responses had initially different sequences in the HIV gene encoding that region. The epitope-specific CTL responses appear to reflect recall responses, as only patients infected with virus containing the vaccine sequence developed them and they could be recalled with a second set of vaccine injections. This appears to be reminiscent of the concept of T cell "original antigenic sin." This vaccine was also immunogenic as measured by gp160-specific lymphocyte-proliferative responses. However, increased immune responses did not impact the HIV load or CTL epitope sequences during therapy.

AIDS Vaccines↗
PubMed1998

Dendritic cells internalize vaccine adjuvant after intramuscular injection.

Vaccine adjuvants help antigens elicit rapid, potent, and long-lasting immune responses. The lack of understanding of the immunological mechanism of action of adjuvants has limited the rational development of vaccines for human use. In particular, little is known about how the immune system processes adjuvants. The goal of the present study was to determine the fate of the vaccine adjuvant MF59, labeled with the fluorescent dye Dil, after injection with fluorescein-labeled gD2 antigen from type 2 herpes simplex virus. At 3 h after intramuscular injection into BALB/c mice, most of the MF59 was still in the form of extracellular droplets in the muscle, but a detectable fraction of the MF59 was in cells in the subcapsular sinus of draining inguinal lymph nodes. At 48 h, most of the MF59 at the site of injection was inside cells that were immunoreactive for the dendritic cell markers DEC-205 and MHC class II molecules, reflecting the interaction of MF59 with antigen presenting cells. At this time, intracellular MF59 was also abundant in the paracortical (T cell) region of lymph nodes. The gD2 antigen was also intracellular in muscle and colocalized MF59 at 48 h, and the presence of MF59 increased the amount of intracellular antigen. Similarly, serological antibody titers to gD2 were 207-fold higher after two injections when MF59 was administered with the antigen. These findings suggest that MF59 interacts with antigen presenting cells at the site of injection and then moves to the draining lymph nodes, where it increases the efficiency of antigen presentation to T cells.

Adjuvants, Immunologic↗
PubMed1998

A pilot clinical trial of HIV antigen-pulsed allogeneic and autologous dendritic cell therapy in HIV-infected patients.

A pilot study was carried out to assess the safety and antigen-presenting properties of allogeneic or autologous dendritic cells (DCs) in six HLA-A2+, HIV-infected patients. Allogeneic DCs obtained from the peripheral blood of HLA-identical, HIV-seronegative siblings were pulsed with recombinant HIV-1 MN gp160 or synthetic peptides corresponding to HLA-A2-restricted cytotoxic epitopes of envelope, Gag, and Pol proteins. The antigen-pulsed cells were infused intravenously six to nine times at monthly intervals and HIV-specific immune responses were monitored. One allogeneic DC recipient with a CD4+ T cell count of 460/mm3 showed increases in envelope-specific CTL- and lymphocyte-proliferative responses, as well as in IFN-gamma and IL-2 production. Another allogeneic DC recipient with a CD4+ T cell count of 434/mm3 also showed an increase in HIV envelope-specific lymphocyte-proliferative responses. A recipient of autologous DCs with a CD4+ T cell count of 730/mm3 showed an increase in peptide-specific lymphocyte-proliferative responses after three infusions. Three other allogeneic DC recipients with CD4+ T cell counts <410/mm3 did not show increases in their HIV-specific immune responses. No clinically significant adverse effects were noted in this study and CD4+ T cell numbers and plasma HIV-1 RNA detected by RT-PCR of all six patients were stable during the study period. Thus, both allogeneic and autologous DC infusions were well tolerated and in patients with normal or near normal CD4+ T cell counts administration of these antigen-pulsed cells enhanced the immune response to HIV. However, since no effect on viral load was observed there was no evidence that this approach provided clinical benefit.

Cell Division↗
PubMed1998

[Evaluation of the actual traceability of labile blood products using medical records].

The traceability of blood products is an essential part of haemovigilance and transfusion safety. A pilot survey assessed the actual traceability by analysing transfusion information collected from medical records of a representative sample of 390 labile blood products transfused in a French university hospital. Transfusion and distribution forms were missing in 2.3% and 6.9% respectively. Availability and validity of transfusion information varied according to the nature of the expected information, elements of patients' records and types of wards. The location where the transfusion was performed was false or ambiguous in 38% of cases in surgery. Crude traceability, evaluated by the feedback of validated distribution forms, was estimated at 85.2% whereas actual traceability was estimated at 81.9% (SD 1.7%). High availability (98.7%) of at least one of the two sheets of the distribution form in medical records, or in the blood bank, revealed that a significant improvement of traceability should come from a better compliance to the rules of information transmission. The actual traceability differed significantly according to clinical services (worse in surgery) and was lower in case of autologous or absence of previous transfusion. An analysis of markers of good traceability should suggest efficient evolution of organization and information systems. This pilot study shows the relevance and feasibility of this kind of survey which could interestingly be performed on a large national representative random sample.

Blood Transfusion↗
PubMed1998

Skin signs in the diagnosis of thallium poisoning.

A 45-year-old man developed a painful and rapidly progressive sensory-motor polyneuropathy associated with confusion and convulsions. This resulted in hypoventilation and led to respiratory failure and coma. A rapid and diffuse alopecia occurred after 3 weeks in the intensive care unit. Examination of hair roots under polarized light detected dystrophic anagen hairs with dark bands caused by empty spaces in the disorganized cortex. These dark zones were originally reported in patients with thallium poisoning and a toxicological investigation confirmed thallium exposure. The classical systemic symptoms and the various dermatological signs are reviewed, and the origins of contamination and physiopathology discussed.

Alopecia↗
PubMed1997

Cloning, sequencing and characterization of the 5'-flanking region of the human collagenase-3 gene.

Collagenase-3 (matrix metalloprotease-13) is a recently discovered human collagenase produced in normal articular cartilage chondrocytes and thought to be involved in the pathological process of osteoarthritis. We have sequenced and characterized 1.6 kb of the human collagenase-3 gene 5'-flanking region. The transcription start site was located 22 bp upstream from the ATG start codon. Sequence analysis of the 5'-flanking region revealed the presence of the consensus recognition sites for the TATA and CCAAT DNA-binding proteins, activator protein-1 and E26 transformation specific/polyoma virus enhancer, as well as three core motifs of hormone response elements. Transient transfection assays demonstrated that a small fragment of 133 bp, containing the activator protein-1 and E26 transformation specific/polyoma virus enhancer sites promoted transcription in normal and osteoarthritic human chondrocytes with significantly higher activity than the original 1.6 kb fragment. Nucleotide sequence comparison of the promoter region of human collagenase-3 revealed a stronger similarity to the mouse collagenase-1 promoter than to the human collagenase-1 promoter.

Animals↗