Jean-Luc Davignon

Traditional cardiovascular risk factors in rheumatoid arthritis: a meta-analysis.

OBJECTIVE Rheumatoid arthritis is associated with increased cardiovascular morbidity and mortality. We performed a systematic review of the literature and a meta-analysis to look for differences in the prevalence of traditional cardiovascular risk factor between RA patients and controls. METHODS Medline database was searched to identify studies evaluating the prevalence of traditional cardiovascular risk factors in rheumatoid arthritis patients and controls. Studies were selected and reviewed by two investigators. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated and pooled using a random-effects model. Statistical heterogeneity was evaluated through the use of Chi2 and I2 statistics. RESULTS Fifteen case-control studies with a total of 2956 patients and 3713 controls met the inclusion criteria. The prevalence of smoking was increased in RA patients in comparison with controls: OR (95%CI) 1.56 (1.35-1.80) (P < 0.00001). The prevalence of hypertension did not differ: OR (95% CI) 1.09 (0.91-1.31) (P = 0.35). The prevalence of diabetes mellitus was increased in RA: OR (95%CI) 1.74 (1.22-2.50) (P = 0.003). The prevalence of hypercholesterolemia did not differ: OR (95%CI) 0.84 (0.67-1.04) (P = 0.11). HDL cholesterol levels were lower in RA patients: weighted mean difference -17.72 mg/dl (-18.35 - -17.08) (P < 0.00001). Significant heterogeneity among studies was found for diabetes mellitus and HDL cholesterol levels. CONCLUSIONS Some traditional cardiovascular risk factors, such as smoking, diabetes mellitus or lower HDL cholesterol levels, appear more prevalent in rheumatoid arthritis patients and could contribute to the increased cardiovascular morbidity and mortality observed in rheumatoid arthritis.

A Phosphorus-Based Dendrimer Targets Inflammation and Osteoclastogenesis in Experimental Arthritis

A phosphorus-based dendrimer suppresses inflammation and reduces bone erosion in mouse models of rheumatoid arthritis. Dendrimer Doubles Up Rheumatoid arthritis (RA) is an autoimmune inflammatory disease that is characterized by inflamed synovial tissue, cartilage degeneration, and bone erosion, leading to joint deformation and physical handicap. Biologic therapeutic approaches, such as monoclonal antibodies and soluble receptors, have been developed to relieve the symptoms of RA. Unfortunately, these drugs typically act on a single target: proinflammatory cytokines. There is an unmet clinical need for anti-RA drugs that target not only proinflammatory molecules and pathways, but also the osteoclastic differentiation of monocytes—a process that leads to bone resorption. In response, Hayder et al. synthesized a new dendrimer-based therapeutic that boasts a two-pronged attack on RA, with both anti-inflammatory and anti-osteoclastogenic activity. Dendrimers are highly branched polymers whose multivalency allows for interaction with several cellular and molecular targets. The authors created an azabisphosphonate (ABP)–capped dendrimer that has been shown to target human monocytes and direct them toward an anti-inflammatory response. Two animal models of autoimmune arthritis were used: the IL-1ra−/− mouse and the K/BxN serum transfer mouse. Dendrimer ABP was administered to IL-1ra−/− mice via weekly intravenous injections. At high doses, the dendrimer completely inhibited inflammation, as evidenced by a decrease in paw swelling, and prevented arthritis histopathology, with ankle joints showing near-normal synovial membranes and intact cartilage after 12 weeks. Dendrimer ABP also decreased the amount of proinflammatory cytokines and increased levels of anti-inflammatory cytokines interleukin-4 (IL-4) and IL-10, thereby suggesting a skewing toward a T helper 2 (TH2) response. The K/BxN mouse demonstrated similar results upon treatment with dendrimer ABP. Treatment with dendrimer ABP also prevented osteoclastogenesis, as shown in human synovial tissue ex vivo and human peripheral blood monocytes in vitro. The authors further outlined a potential dendrimer-mediated mechanism that involves inhibition of c-FMS—a signaling molecule that promotes monocyte differentiation into osteoclasts. This study by Hayder and colleagues has shown that dendrimer ABP, by doubling up against inflammation and bone erosion, might be more effective at treating RA than existing antibody- and small-molecule–based biologic drugs. Dendrimers are highly branched “tree-like” polymers that have demonstrated therapeutic potential in drug delivery, medical imaging, and tissue engineering in recent years. In addition, we have shown that an azabisphosphonate (ABP)–capped dendrimer selectively targets monocytes and directs them toward anti-inflammatory activation. We explored this property to assess the therapeutic potential of dendrimer ABP in the treatment of an inflammatory disease, rheumatoid arthritis. Intravenous injections of dendrimer ABP inhibited the development of inflammatory arthritis in two animal models: IL-1ra−/− mice and mice undergoing K/BxN serum transfer. Suppression of disease was characterized by normal synovial membranes, reduced levels of inflammatory cytokines, and the absence of cartilage destruction and bone erosion. Dendrimer ABP also exhibited anti-osteoclastic activity on mouse and human cells, mediated by c-FMS (cellular-feline McDonough strain sarcoma virus oncogene homolog) inhibition. These preclinical demonstrations suggest the potential use of dendrimer ABP as a nanotherapeutic for rheumatoid arthritis.

Analysis of the Proliferative T Cell Response to Human Cytomegalovirus Major Immediate‐Early Protein (IEl): Phenotype, Frequeney and Variability*

Cellular immune responses are important in the recovery from human cytomegalovirus (HCMV) infection. However, little is known about the CD4+ T cell response and the target antigens (Ag) recognized. In this paper, we have analysed the proliferative T cell response of healthy HCMV seropositive (HCMV+) blood donors to recombinant immediate‐early proteins expressed in trans‐fected astrocytoma cells and to total HCMV Ags expressed in infected astrocytoma cells. We found that CD4+ T cells were the major cell population that proliferated in the presence of IE or total HCMV Ags. Among healthy HCMV seropositive blood donors with anti‐HCMV specific proliferative response, 33–44% also responded to IE Ags. Moreover, in high responders, the precursor frequencies of cells which proliferated in the presence of total HCMV, IE, or IEl Ags were high (1/103 to 1/255, 1/2785 to 1/7744 and 1/5190 to 1/13531, respectively). In some donors, the anti‐IE response was variable over time, whereas the anti‐total HCMV Ags response remained constant, which suggests regulation of the anti‐IE response in immunocompetent subjects. Our results suggest that the CD4+ anti‐IEl response represents a significant part of the anti‐HCMV proliferative response, both at the population level, and within individual immune systems.

Inhibition of IFN-γ-Induced STAT1 Tyrosine Phosphorylation by Human CMV Is Mediated by SHP2

Human CMV (HCMV) is a ubiquitous β-herpesvirus which has developed several mechanisms of escape from the immune system. IFN-γ-induced signaling relies on the integrity of the JAK/STAT pathway which is regulated by phosphorylation steps and leads to nuclear translocation of tyrosine-phosphorylated STAT1 (STAT1-P-Tyr), and its binding to IFN-γ activation site sequences of IFN-γ-inducible promoters. Activation of those promoters leads to the expression of genes involved in the immune response and in the antiviral effects of IFN-γ. Src homology region 2 domain-containing phosphatase 2 (SHP2) is a ubiquitous phosphatase involved in the regulation of IFN-γ-mediated tyrosine phosphorylation. Several mechanisms account for the inhibition IFN-γ signaling pathway by HCMV. In this study, we have identified a new mechanism that involved the inhibition of STAT1 tyrosine phosphorylation within 12–24 h postinfection. This defect was dependent on HCMV transcription. Consequences were impaired nuclear translocation of STAT1-P-Tyr, inhibition of IFN-γ activation site-STAT1 interaction, and inhibition of HLA-DR expression. Expression of indoleamine-2,3-dioxygenase which is involved in the antiviral effects of IFN-γ was also inhibited. Treatment of cells with sodium orthovanadate rescued STAT1 tyrosine phosphorylation, suggesting that a tyrosine phosphatase was involved in this inhibition. Coimmunoprecipitation of STAT1 and SHP2 was induced by HCMV infection, and SHP2 small interfering RNA restored the expression of STAT1-P-Tyr. Our data suggest that SHP2 activation induced by HCMV infection is responsible for the down-regulation of IFN-γ-induced STAT1 tyrosine phosphorylation.

Combination of human cytomegalovirus recombinant immediate-early protein (IE1) with 80 nm cationic biovectors: protection from proteolysis and potentiation of presentation to CD4+ T-cell clones in vitro

We have shown in a previous study that the proliferative CD4+ T-cell response to the regulatory immediate-early protein IE1 was a major component of the overall anti viral response in human cytomegalovirus (HCMV) seropositive blood donors. This viral antigen may be valuable in subunit vaccine design, since anti IE1 CD4+ T cells might provide help for production of antibodies and cytotoxic T lymphocytes (CTL) responses, and could take part in the control of viral infection. Preliminary to the elaboration of future vaccine formulations, we developed immunogenic complexes resulting from the combination of a purified recombinant protein derived from the fusion of Escherichia coli glutathione-S-transferase (GST) and a large C-terminal fragment (e4) of IE1, with new 80 nm cationic synthetic particles called Biovectors. We have shown that the antigen GST-e4 was stably complexed to vectors and that, contrary to the soluble form, it was protected from proteolysis in cell culture medium. By confocal microscopy we observed that the synthetic vectors were internalized by lymphoblastoid B cells, providing a significant enhancement of antigen delivery in antigen presenting cells (APC). Indeed, we demonstrated that the previous combination of antigen with particles, significantly enhanced the proliferation of specific CD4+ T-cell clones directed against IE1 in vitro, when either HLA-matched isolated peripheral blood mononuclear cells or EBV transformed B cell lines were used as APC. The relevance of these observations to the use of these new vectors for vaccine design against HCMV is discussed.

Activities of Z‐ajoene against tumour and viral spreading in vitro

Z‐ajoene is a garlic‐derived compound with known anti‐tumour properties. This report argues in favour of pro‐apoptotic and cell cycle blockage activities of Z‐ajoene on various cell lines involving activation of the p53‐family gene products, p53, p63 and p73, at indicated doses. According to its known anti‐proteasome activity, Z‐ajoene induced a downregulation of MHC‐class I expression at the surface of treated cells but did not impair their recognition by CD8+ T cells. We further demonstrated a new activity of Z‐ajoene against human cytomegalovirus spreading in vitro that was mediated by an increased number of apoptotic cells after infection. Altogether our data point at the ubiquitous efficiency of Z‐ajoene as a new compound to fight against cancers of various origins including those that put up viruses.

An Azabisphosphonate-Capped Poly(phosphorhydrazone) Dendrimer for the Treatment of Endotoxin-Induced Uveitis

Over the last decade, different types of dendrimers have shown anti-inflammatory properties in their own right. In particular, we have shown that poly(phosphorhydrazone) (PPH) dendrimers are able to foster an efficient anti-inflammatory response in human monocytes and can resolve the main physiopathological features of chronic arthritis in mice at 1 mg/kg. Here we afford new insights into the therapeutic potential of an azabisphosphonate-capped dendrimer (dendrimer ABP). We have challenged its anti-inflammatory and immuno-modulatory properties in a robust rat model of acute uveitis induced by lipopolysaccharide (LPS). We show that dendrimer ABP at 2 µg/eye is as efficient as the “gold standard” dexamethasone at 20 µg/eye. We have demonstrated that the effect of dendrimer ABP is mediated at least through an increase of the production of the anti-inflammatory Interleukin(IL)-10 cytokine.

Multiple cytolytic t-cell clones with distinct cross-reactivity patterns coexist in anti-self + hapten cell lines.

C57BL/10 T cells sensitized with TNBS-treated syngeneic cells and maintained in culture by repeated stimulations exhibit high cytolytic activity toward syngeneic TNBS-treated target cells with marked cross-reactivity on TNBS-treated target cells from mice of independent H-2 haplotypes (ten tested). The analysis of the reactivities of 48 T-cell clones derived by limiting dilution from such T-cell populations revealed three types of cytotoxic T-cell clones: (1) clones restricted by H-2Kb + TNP without cross-reaction on TNBS-treated or untreated target cells of other tested mouse haplotypes; (2) clones that lysed H-2b + TNP and also TNBS-treated target cells from not more than one, two or three different H-2 haplotypes; (3) clones that lysed untreated H-2k target cells. No T-cell clone was found to exhibit the wide pattern of cross-reactivity on any TNBS-treated mouse cell, characteristic of the original T-cell populations, indicating that these were composed of individual T-cell clones specific for TNP + private or for TNP + distinct “public” H-2 determinants. Correlation with described serological public H-2 specificities was possible for some cytotoxic T-cell clone reactivity, but not for others. The general pattern of T-cell reactivity as revealed by clonal analysis in this study, as well as in published work, includes cross-reactions between self H-2a + X and allogeneic H-2n + X, between self H-2a + X and unmodified allogeneic H-2n, or between allogeneic H-2n and allogeneic H-2m + X, and is consistent with the hypothesis that MHC-class restriction is the main rule in T-cell recognition.

Maintenance of cytomegalovirus-specific CD4pos T-cell response in rheumatoid arthritis patients receiving anti-tumor necrosis factor treatments.

IntroductionAnti-tumor necrosis factor (TNF)-α biotherapies have considerably changed the treatment of rheumatoid arthritis (RA). However, serious infections are a major concern in patients with rheumatic diseases treated with anti-TNF-α. Little is known about viral, especially latent, infections in anti-TNF-α treatments. Infections by cytomegalovirus (CMV), a β-herpes virus, are frequent and induce a strong CD4pos T-cell immunity, which participates in the control of infection. We thus have chosen to analyze the CD4pos T-cell response to CMV antigens as a model of antiviral response in RA patients treated with anti-TNF-α. CD28 expression was evaluated.MethodsWe have measured the CD4pos response to CMV antigens in RA patients, before and after initiation of treatment with an anti-TNF-α agent. The intracellular production of interferon (IFN)-γ in total and CD28neg CD4pos T cells in response to CMV antigens (Ags) was evaluated with flow cytometry. The proliferation of total CD4pos T cells in the presence of CMV antigens was measured with 3H-thymidine incorporation.ResultsAnti-TNF-α treatments impaired neither the anti-CD4pos anti-CMV IFN-γ response nor the proliferative response in patients. The percentage of CD28neg CD4pos cells remained constant.ConclusionsOur data suggest that the CD4pos T-cell response against CMV is not altered by anti-TNF-α treatments and that infection remains controlled in treated RA patients latently infected with CMV. Our observation brings new insight into the current knowledge of the risks of infection in patients treated with anti-TNF-α biotherapies.

IE1-pp65 recombinant protein from human CMV combined with a nanoparticulate carrier, SMBV, as a potential source for the development of anti-human CMV adoptive immunotherapy

BACKGROUND Human cytomegalovirus (HCMV) infection and reactivation following allogeneic bone marrow transplantation is a major source of complications in grafted patients including pneumonitis, graft rejection and even death. Adoptive immunotherapy consisting in transfer of CD4(+) and CD8(+) T cells directed against HCMV has proved its worth. Nevertheless, established procedures have to be improved in terms of safety and waiting period required to obtain specific T cells. METHODS As an alternative to infectious virus used in current strategies, we purified a recombinant protein IE1-pp65 resulting from the fusion of the regulatory IE1 and matrix pp65 proteins, both known as the major targets of the overall anti-HCMV T cell response. Based on our previous data demonstrating its use for in vitro stimulation and expansion of anti-HCMV CD4(+) and CD8(+) T cells (Vaz-Santiago et al, 2001, J.Virol, 75:7840-47) from peripheral blood mononuclear cells (PBMC) of seropositive donors, we planned to improve its in vitro immunogenicity through association with a nanoparticulate carrier, SMBV. RESULTS We demonstrated that using of SMBV/IE1-pp65 formulation allowed to potentiate in vitro activation of T cells and to expand more CD8(+) T cells than with soluble IE1-pp65, following stimulation of PBMC. DISCUSSION These data suggest the use of SMBV/IE1-pp65 formulation as a potential source of antigen for efficient T cells expansion in the development of safe anti-HCMV immunotherapy.