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N Bessis

Publications and source records attributed to N Bessis.

At least 19 recordsLinked to original sources
PubMed2004

Active immunization against murine TNFalpha peptides in mice: generation of endogenous antibodies cross-reacting with the native cytokine and in vivo protection.

New lines of treatment targeting cytokines have been successfully developed recently and are now widely used in therapy. They are based on passive administration of cytokine inhibitors either soluble receptors or mAbs and the major example is TNFalpha in rheumatoid arthritis (RA). Since a few years, our group has developed a novel alternative approach targeting cytokines by using active immunization against biologically inactive but immunogenic cytokine derivatives. In the present work, we present a new aspect of this research, based on immunization against specific cytokine peptides chosen by molecular modelling. We could elicit a significant humoral response against four TNFalpha peptides by active immunization, and show that the Abs generated cross-reacted with the native cytokine with good titers as determined by ELISA. Interestingly, during coimmunization experiments with couples of peptides, one showed a clear immunodominant effect over the other. Overall, we could not show the neutralization of TNFalpha biological activity in vitro by the immunized sera, but it seems that it is not a prerequisite to observe clinical efficacy. Indeed, using the LPS/galactosamine-induced shock, we could demonstrate that one of the four peptides tested conferred a clinical protection. These results validate the feasibility and efficacy of active immunization against cytokine peptides, and confirm that active immunization against cytokines could represent in the future an alternative to passive immunization in many diseases.

Amino Acid Sequence↗
PubMed2004

Immune responses to gene therapy vectors: influence on vector function and effector mechanisms.

Circumventing the immune response to the vector is a major challenge with all vector types. Viral vectors are the most likely to induce an immune response, especially those, like adenovirus and AAV, which express immunogenic epitopes within the organism. The first immune response occurring after vector transfer emerges from the innate immune system, mainly consisting in a rapid (few hours) inflammatory cytokines and chemokines secretion around the administration site. This reaction is high with adenoviral vectors and almost null with AAV. It is noteworthy that plasmid DNA vectors, because of CpG stimulatory islets, also stimulate the innate immunity via the stimulation of TLR receptors on leukocytes. Specific immune response leading to antibodies production and T lymphocytes activation also occurs within a few days after vector introduction. Capsid antigens are mostly responsible for specific immunity toward adenoviruses, and are also involved in the response against AAV. In the former case only, however, viral gene-encoded proteins can also be immunogenic. The pre-existing humoral immunity coming from early infections with wild-type AAV or adenovirus can prevent efficient gene transfer with the corresponding vectors. In all cases, some parameters like route of administration, dose, or promoter type have been extensively described as critical factors influencing vector immunity. Strategies to fight against vector-induced immunity can come from the immunology field, since tolerance induction or immunosuppression are a possibility. Alterations to vector structure have also been extensively performed to circumvent the immune system and thus enhance gene transfer efficiency and safety.

Adenoviridae↗
PubMed2001

Novel pro-inflammatory interleukins: potential therapeutic targets in rheumatoid arthritis.

Among potential targets for nonspecific anti-inflammatory immunointervention, three pro-inflammatory interleukins (ILs) have recently been found to play a pivotal role in rheumatoid arthritis (RA). IL-15 has both chemoattractant and proinflammatory properties and may promote bone destruction. IL-17, a product of T lymphocytes, has proinflammatory effects and induces production of metalloproteinases such as MMP-1. IL-18 not only has proinflammatory, angiogenic, and chemoattractant effects but also promotes cartilage destruction. These cytokines are potential targets for specific or nonspecific anti-inflammatory therapy. Thus, blocking IL-15 by its receptor reduces the severity of experimental collagen-induced arthritis (CIA). In this model, IL-17 levels fall after administration of anti-inflammatory cytokines such as IL-4 or IL-13. Finally, monoclonal anti-IL-18 antibodies prevent streptococcal cell wall arthritis, and IL-18 binding protein, which is a naturally occurring IL-18 inhibitor, prevents CIA.

Animals↗
PubMed2000

Expression of Fas ligand improves the effect of IL-4 in collagen-induced arthritis.

The present study was aimed at investigating whether the expression of Fas ligand (FasL) by CHO cells transfected with IL-4 (CHO/IL-4) or IL-10 (CHO/IL-10) genes would improve the effect of the cytokine. DBA/ 1 mice immunized with type II collagen were treated with suboptimal doses of transfected CHO cells (a single s. c. injection of 2 x 10(5) cells) around onset of arthritis. Severe collagen-induced arthritis (CIA) developed in the control groups injected with PBS, CHO /beta-galactosidase/FasL, CHO/IL-4 or CHO/IL-10 cells. In contrast, administration of CHO/IL-4/FasL, but not CHO/IL-10/FasL, cells significantly reduced the clinical severity and resulted in rapid and sustained suppressive effect. Amelioration of CIA was not due to a prolonged in vivo secretion of IL-4 since expression of FasL by CHO cells shortened the in vivo survival of the xenogeneic cells. In fact, administration of FasL(+) cells was associated with a decreased proportion of Mac1(+) neutrophils in the blood and an increased expression of myeloperoxidase at the site of engineered cell engraftment. These findings suggest that the mechanism underlying the beneficial effect of IL-4 delivered by cells expressing FasL involves the combination of the anti-inflammatory properties of IL-4 and the apoptosis of Fas(+) Mac1(+) granulocytes participating in the pathogenic process.

Animals↗
PubMed2000

The type II decoy receptor of IL-1 inhibits murine collagen-induced arthritis.

IL-1 is a key cytokine involved in the inflammatory response. The type II receptor of IL-1 (IL-1RII) acts as a decoy receptor, binding and inhibiting the effect of IL-1. This study was undertaken to establish whether IL-1RII can ameliorate collagen-induced arthritis, a model of inflammatory arthritis in mice. We used human keratinocytes transfected with the human (h)IL-1 RII gene as a source of hIL-1 RII protein. We showed that these cells expressed both the membrane and soluble form of receptor. In vitro, IL-1-stimulated murine macrophage cells showed a decreased expression of TNF-alpha in the presence of hIL-1 RII. We engrafted the hIL-1RII-transfected cells in the back of mice developing collagen-induced arthritis. We found that clinical and histological parameters of arthritis were significantly decreased in mice treated with cells producing hIL-1RII. In addition, hIL-1RII administration was able to reduce the expression of mRNA for IL-6 and myeloperoxidase in the joints of treated animals. These data show that hIL-1 RII anti-inflammatory properties in the model of collagen-induced arthritis in mice and could have a regulatory role in rheumatoid arthritis.

Animals↗
PubMed2000

Adeno-associated virus-mediated delivery of IL-4 prevents collagen-induced arthritis.

Immunomodulation of autoimmune inflammatory diseases like rheumatoid arthritis can be achieved by anti-inflammatory T2 cytokines such as interleukin (IL)-4 administered by gene therapy. In this study we investigated the efficiency of adeno-associated viruses (AAV) vectors in collagen-induced arthritis (CIA). After injection of AAV-LacZ in the tarsus area of mice, the expression of the transgene was localized in the deep muscles cells near the bone. LacZ expression was found in liver, heart and lung after i.m. injection of AAV-LacZ, showing a spread of the vector over the body. Anti-AAV neutralizing antibodies were detected in the serum after i.m. injection of AAV-LacZ, but they did not alter the transgene expression after re-administration of AAV-LacZ. Long-term IL-4 expression persisted 129 days after intra-muscular injection of 3.7 x 10(10) or 11.2 x 10(10) AAV-IL-4 p.p. (average 7.7 or 17.5 pg IL-4/mg proteins, respectively). More importantly, the treatment of CIA with AAV-IL-4 vector in mice produced a therapeutic benefit, since we show a diminished prevalence of the disease, a significant reduction in paw swelling, attenuated histological synovitis and a 10 days delayed onset of arthritis. This is the first evidence that AAV vector-mediated gene therapy using a T2 cytokine is efficient in an animal model of rheumatoid arthritis.

Analysis of Variance↗
PubMed1999

Encapsulation in hollow fibres of xenogeneic cells engineered to secrete IL-4 or IL-13 ameliorates murine collagen-induced arthritis (CIA).

A strategy of gene therapy using IL-4 or IL-13 xenogeneic transfected cells encapsulated into permeable hollow fibres (HF) was used to treat CIA. Hydrogel-based hollow fibres were obtained from AN-69 copolymer, already known for its biocompatibility and tolerance in rodents. Permeability to IL-4 and lack of cell leakage from the fibres were ascertained in vitro and in vivo. Chinese hamster ovary (CHO) fibroblasts transfected with mouse IL-4 gene were encapsulated in HF (6.25 x 105 cells/HF). IL-4 was detected in vitro in the culture supernatant of filled fibres for at least 19 days. IL-4 or IL-13 transfected CHO cells encapsulated in HF were implanted in the peritoneum of mice on days 11-13 after immunization with type II collagen. Control mice were treated with fibre containing CHO cells transfected with beta-galactosidase (betagal) gene; a positive control group consisted of mice treated by subcutaneous injection of 106 cells on days 10 and 25. Mice were monitored for signs of arthritis by observers unaware of the status of animals. Results of these experiments indicate that severity of the articular disease was significantly reduced in the groups of mice treated with CHO/IL-4 or CHO/IL-13 cells encapsulated in HF, compared with control groups receiving CHO/betagal cells encapsulated in HF. Histological analysis confirmed these data and extended them to a better inhibitory effect of encapsulated cells compared with free cells on inflammatory and destructive joint disease. Moreover, such long-term treatment with HF was well tolerated; macroscopic and histological aspects of peritoneal cavity were moderately inflammatory. Thus, our results may have important implications for clinical use of gene transfected cells as therapeutic agents in the treatment of autoimmune diseases.

Acrylic Resins↗
PubMed1998

[Gene therapy in rheumatoid polyarthritis: perspectives].

THE CONCEPT OF GENE THERAPY: Gene therapy is applicable in diseases involving several genes such as rheumatoid arthritis. Gene transfer is the insertion in vivo of genetic material necessary to produce a molecule with therapeutic action. This strategy is currently in experimental stages; feasibility studies in humans are in the preliminary stage. SEVERAL TARGETS: In experimental models of rheumatoid arthritis, the most widely studied target genes are those which code for inflammation inhibitors such as IL-1 receptor antagonists or anti-inflammatory cytokines (IL-4, IL-10, IL-13). Another interesting target would concern genes coding for molecules inhibiting joint destruction (for example metalloprotease inhibitors). VECTORS: The development of high-performance vectors (both viral and nonviral vectors) will greatly improve the expected benefit/risk potential of gene therapy in general. IN RHEUMATOID ARTHRITIS: The particular problem in rheumatoid arthritis is the choice of the transfection site. An articular site would require multiple injections in the different affected joints. A systemic approach would take into account the general disseminated nature of the disease.

Animals↗
PubMed1998

Modulation of proinflammatory cytokine production in tumour necrosis factor-alpha (TNF-alpha)-transgenic mice by treatment with cells engineered to secrete IL-4, IL-10 or IL-13.

TNF-alpha is one of the major proinflammatory cytokines involved in the pathogenesis of chronic inflammatory joint disease, in human rheumatoid arthritis as well as in murine models of this disease. It was previously described that a highly destructive chronic spontaneous inflammatory arthritis develops in mice expressing a human TNF-alpha transgene modified with the 3' untranslated region of beta-globin. The present study investigates in this mouse model the effects of the anti-inflammatory cytokines IL-4, IL-10 and IL-13 administered in vivo on proinflammatory cytokine expression. Groups of TNF-alpha-transgenic mice were engrafted with xenogeneic transfected Chinese hamster ovary (CHO) fibroblasts secreting murine IL-4, IL-10 or IL-13. In vivo treatments consisted of 3 or 4 weekly engraftments, starting when the mice were 4weeks old. Control groups of transgenic mice were engrafted with beta-galactosidase gene-transfected CHO cells or injected with medium. A significant decreased expression of TNF-alpha transgene, endogenous mouse TNF-alpha and IL-1 mRNA was observed in splenocytes of mice treated for 3 or 4 weeks with CHO/IL-4 and CHO/IL-13, and, to a lesser extent, with CHO/IL-10, compared with controls. Finally, attenuation of histological scores of arthritides was statistically significant only in the group of CHO/IL-4-treated mice after 3weeks of treatment (P<0.05), and was not significant in any other group. These results show that IL-4, IL-10 or IL-13, administered by gene therapy, can decrease the mRNA steady state levels of both endogenous and transgenic cytokines in human TNF-alpha transgenic mice. In addition, IL-4 can slightly attenuate the development of arthritides in this model.

Animals↗
PubMed1997

High susceptibility to collagen-induced arthritis in mice lacking IFN-gamma receptors.

Collagen-induced arthritis (CIA), an animal model for rheumatoid arthritis, is induced in DBA/1 (H-2q) mice following immunization with type II collagen (CII) in CFA. Since we have previously shown that IFN-gamma exerts a biphasic effect during the evolution of CIA in DBA/1 mice, we analyzed the development of this disease in mice with a disruption of the IFN-gamma receptor gene (IFN-gammaR(0/0)). Mutant mice were interbred with the DBA/1 strain to yield IFN-gammaR(0/0) mice expressing the H-2q haplotype. In three consecutive experiments, IFN-gammaR(0/0) male mice were found to exhibit severe clinical and histologic arthritis with an average incidence of 88.5 vs 94.1% for the wild DBA/1 strain. Notably, onset of clinical symptoms occurred significantly earlier than in DBA/1 mice. Although of a lower magnitude than in males, CIA also developed early in IFN-gammaR(0/0) female mice and with higher clinical severity than in control DBA/1 females. Immunization of knockout mice with CII resulted in the generation of CII-specific T cells belonging to the Th1 phenotype that recognize the same immunodominant peptides as do DBA/1 mice. CIA in IFN-gammaR(0/0) mice was associated with a down-regulation of the CII-specific IgG response, and this impairment was essentially due to a strong reduction of Abs of the IgG2a isotype. Taken together, our findings provide evidence that IFN-gammaR deficiency in DBA/1 mice leads to the occurrence of severe CIA with an accelerated onset compared with that in wild-type mice, indicating that the proinflammatory action of IFN-gamma has been bypassed in the IFN-gammaR(0/0) mice.

Animals↗
PubMed1997

Interleukin-10-mediated T cell apoptosis during the T helper type 2 cytokine response in murine Schistosoma mansoni parasite infection.

The pathogenesis of infection with the helminth parasite Schistosoma (S) mansoni in mice has been reported to involve a T helper (Th)1 to Th2 cytokine switch, associated with a pathogenic granulomatous response to parasite eggs and to a global defect in Th1-cell effector functions. Here we report that the Th2 cytokine response, which begins 6 weeks after infection, at the time of parasite egg laying (i) does not occur in the context of a genuine Th1 to Th2 cytokine switch, but is associated with a persistent capacity of Th1 (or Th0) cells to secrete IL-2 and IFN-gamma in response to T cell receptor (TCR) stimulation; (ii) is associated, in vitro, with spontaneous death by apoptosis of a significant fraction of the CD4 and CD8 T cells, which is greatly enhanced by TCR stimulation; and (iii) is associated, in vivo, with numerous and large clusters of apoptotic cells in the spleen and in the inflammatory infiltrates surrounding the parasite egg deposits in the liver. The in vitro addition of antibodies to the Th2 cytokine IL-10 had both a preventive effect on TCR-induced T cell apoptosis and an enhancing effect on TCR-induced T cell secretion of Th1 cytokines. Taken together, these findings suggest that the downregulation of Th1-cell-mediated effector functions in S. mansoni-infected mice may not be related to a lack of Th1 cell production, but to a process of IL-10-mediated and activation-induced premature T cell death, that include Th1 (or Th0) cells. Further identification of mechanisms involved in the regulation of T cell apoptosis has implications for the understanding of the pathogenesis of immunosuppression associated with chronic infectious diseases.

Animals↗
PubMed1996

Attenuation of collagen-induced arthritis in mice by treatment with vector cells engineered to secrete interleukin-13.

The anti-inflammatory effects of the recently identified cytokine interleukin (IL)-13 on collagen-induced arthritis (CIA) was explored and compared to those of IL-4 using systemic administration of these cytokines via two injections of xenogeneic vector cells transfected with a plasmid construct. CIA was induced in DBA/I mice by immunization with native bovine type II collagen (CII). Chinese hamster ovary (CHO) fibroblasts transfected with the mouse IL-13 or IL-4 genes were inoculated subcutaneously on days 10 and 25 post-priming with CII and mice were monitored for signs of arthritis by observers unaware of the status of the animal. Incidence and severity of CIA were significantly reduced in the groups of mice treated with IL-13 and IL-4 gene-transfected CHO cells compared to control groups receiving nontransfected cells. Expression of various cytokines in spleen cells from individual mice was assessed by quantitative reverse transcriptase-polymerase chain reaction at different times after immunization. Our data show that IL-13-induced suppression of CIA coincided with a decreased TNF-alpha mRNA expression in the spleen of treated animals. This may explain at least partially the anti-inflammatory effects of IL-13 in CIA. Thus, our results may have important implications for the clinical use of T helper (Th)1/TH2 modulatory cytokines as therapeutic agents in the treatment of autoimmune diseases.

Animals↗
PubMed1996

[Experimental gene therapy in models of inflammatory arthritis].

Gene therapy is rheumatoid arthritis is presently in an experimental phase. Genes encoding for antiinflammatory proteins can be transfected in joint cells. Therefore gene encoding for interleukin-1 receptor antagonist has been transfected into synovial cells or into chondrocytes. Gene expression can be maintained as long as 8 weeks after cell transfer. We have reported that clinical and histopathological parameters of collagen-induced arthritis (an animal model of rheumatoid arthritis) can be reduced by engraftment of CHO cells transfected with genes encoding for antiinflammatory cytokines such as interleukine-4 or interleukine-13. Some of the questions which need to be assessed before planning clinical trial are the choice of vectors and the most efficient target cells; and the genes to be transfected have to be chosen among many candidates.

Animals↗
PubMed1995

Biphasic effect of interferon-gamma in murine collagen-induced arthritis.

Interferon-gamma (IFN-gamma) exerts both enhancing and suppressing influences on collagen-induced arthritis (CIA), depending on the route and protocol of administration. To study the role of IFN-gamma on the autoimmune process of CIA, we treated DBA/1 mice with two different rat monoclonal antibodies (mAb) to murine IFN-gamma. Treatments, given twice weekly for 4 weeks, consisted of intraperitoneal injections of either mAb. In early treatments, starting from the day of immunization with type II collagen (CII), the severity of arthritis was reduced in both groups of anti-IFN-gamma-treated mice compared with control groups. Moreover, anti-CII antibody levels decreased in the sera of these mice. CIA was also down-regulated in mice treated from days 14 or 28 post immunization. In contrast, late treatments with anti-IFN-gamma mAb either induced aggravating effects, or did not affect the course of the disease. On the other hand, administration of high doses (8 x 10(4) U three times/week) of rat recombinant IFN-gamma exerted a transient increase of CIA severity. These findings suggest that IFN-gamma may play a critical role during both the induction and the course of CIA, first enhancing the immune response, and then regulating the arthritis process.

Animals↗
PubMed1995

[Treatment of inflammation with anti-inflammatory cytokines: example in models of auto-immune diseases].

Cytokines may exert anti-inflammatory properties, allowing the hypothesis of their potential therapeutic use. Targeting the cytokines balance may modify the course of subsequent inflammatory events in an autoimmune disease. Many data are available. Interferon-gamma can be blocked by an anti-interferon-gamma monoclonal antibody: if the treatment is administered in the early phase of an autoimmune disease such as collagen-induced arthritis, the course of the disease is worsened; if the treatment is given later, the disease can be improved; these results are mirrored by treatment with high doses of the cytokine itself. Pharmacologic effects of antiinflammatory cytokines such as interleukin (IL)-4, IL-10 or IL-13 are a protection against several experimental autoimmune diseases. The very short half-life of cytokines makes them difficult and expensive to use directly; in such occurrence, high quantities have to be frequently injected. In this context, gene therapy appears as an effective alternative solution: the transfection of cells with cytokines genes (e.g. either IL-4 or IL-13) then the engraftment of these vectors in animals, permit the in vivo secretion of high levels of cytokines, and result in the protection of the animals from the development of the disease.

Animals↗