Current theories propose that systemic lupus erythematosus develops when genetically predisposed individuals are exposed to certain environmental agents, although how these agents trigger lupus is uncertain. Some of these agents, such as procainamide, hydralazine, and UV light inhibit T cell DNA methylation, increase lymphocyte function-associated antigen 1 (LFA-1) (CD11a/CD18) expression, and induce autoreactivity in vitro, and adoptive transfer of T cells that are made autoreactive by this mechanism causes a lupuslike disease. The mechanism by which these cells cause autoimmunity is unknown. In this report, we present evidence that LFA-1 overexpression is sufficient to induce autoimmunity. , hydralazine, and UV light can trigger human lupus (1, 2). These agents also inhibit T cell DNA methylation, and polyclonal as well as cloned human and murine CD4 ϩ T cells become autoreactive after treatment with these and other DNA hypomethylating agents (3-7). Adoptive transfer of T cells made autoreactive by this mechanism causes a lupuslike disease in unirradiated syngeneic recipients (6, 7), suggesting a mechanism by which these agents might induce lupus. However, how these agents modify T cells to make them pathogenic is unknown. LFA-1 overexpression was induced on cloned murineThe autoreactivity correlates with lymphocyte functionassociated antigen 1 (LFA-1) (CD11a/CD18) overexpression, and concentrations of anti-CD11a insufficient to affect antigen reactivity will completely inhibit the autoreactive response (8). This suggests that LFA-1 overexpression contributes to the autoreactivity, and inhibiting function of the additional molecules reverses it (8). Cloned human T cells transfected with a CD18 cDNA also overexpress CD11a/CD18 and become autoreactive (5), further supporting the relationship between LFA-1 overexpression and T cell autoreactivity. These observations raise the possibility that LFA-1 overexpression might also contribute to the development of autoimmunity induced by hypomethylated T cells. However, inhibiting T cell DNA methylation probably affects expression of multiple genes, and the ability of the hypomethylated cells to induce autoimmunity may require altered expression of more than one gene. In this report, we examined the role of LFA-1 overexpression in autoimmunity by stably transfecting a cloned murine T cell line with a CD18 cDNA construct. We then asked if the transfected cells become autoreactive and induce a disease similar to that caused by treating the same cells with Pca, a DNA methylation inhibitor. MethodsMice and peritoneal macrophage (Mø) isolation. Young (6-8 wk of age) female AKR (H-2, and SJL (H-2 s ) mice were obtained from The Jackson Laboratories (Bar Harbor, ME) and maintained in a specific pathogen-free environment. Peritoneal Mø were obtained by i.p. thioglycollate (Becton Dickinson and Co., Cockeysville, MA) injection and harvested 3 d later as previously described (6, 7).T cell culture. D10.G4.1 cells (9), obtained from the American Type Culture Collection (Rock...
Objective. Antigen-specific CD4+ T cells treated with DNA methylation inhibitors become autoreactive, suggesting a novel mechanism for autoimmunity. To test whether this mechanism might be involved in systemic lupus erythematosus (SLE), phenotypic markers for the autoreactive cells were sought.Methods. Cloned normal T cells were treated with the DNA methylation inhibitor 5-azacytidine (5-azaC) and studied for altered gene expression. T cells from patients with active SLE were then studied for a similar change in gene expression, and cells expressing the marker were tested for autoreactivity.Results. 5-azaC-treated normal T cells had increased CDlla (leukocyte function-associated antigen la) expression relative to other membrane molecules. A T cell subset with similar CDlla expression was found in patients with active SLE. This subset contained cells that spontaneously lysed autologous macrophages, with a specificity similar to that of 5-azaC-treated cells. Conclusion. The model of 5-azaC-induced autoreactivity may have relevance to SLE.Antigen-specific CD4+ T cell clones respond to autologous macrophages (Mgi) without antigen, following treatment with DNA methylation inhibitors such as 5-azacytidine (5-azaC). The response is inhibited by monoclonal antibodies (MAb) against CD3 and class I1 major histocompatibility complex (MHC) determinants, and occurs with autologous but not allogeneic Mgi (1,2), suggesting that the cells are responding to autologous class I1 MHC determinants via a pathway involving the antigedMHC receptor. Similar concentrations of 5-azaC alter gene expression in a wide range of cell types, including T cells (3-3, and the autoreactivity may be caused by changes in the expression of as-yet-unidentified genes involved in T cell activation.5-azaC-induced autoreactivity may have relevance to autoimmunity. Recent experiments have shown that murine T cells can become autoreactive following 5-azaC treatment, responding to and, intriguingly, lysing, syngeneic Mgi. Adoptive transfer of murine 5-azaC-treated cells induces an immune complex glomerulonephritis and anti-DNA antibodies in nonirradiated syngeneic mice (6). These findings suggest a novel model for systemic lupus erythematosus (SLE), in which T cell DNA hypomethylation could alter expression of crucial genes, resulting in T cell autoreactivity, and the autoreactive T cells could then produce a lupus-like illness. Reports that lupusinducing drugs inhibit T cell DNA methylation and induce autoreactivity (7) support this concept. Moreover, recent evidence indicates that T cell DNA methylation is impaired in patients with active SLE (8).
Objective. To determine if DNA methylation inhibitors make T cells autoreactive by inducing lymphocyte function-associated antigen type 1 (LFA-1) ( C D l l d CD18) overexpression.Methods. T cell clones were treated with 3 distinct DNA methylation inhibitors or were stably transfected with a CD18 cDNA in a mammalian expression vector, and the effects on LFA-1 expression and activation requirements were examined.Results. LFA-1 overexpression, caused by DNA methylation inhibitors or by transfection, correlates with the development of autoreactivity.Conclusion. LFA-1 overexpression may contribute to T cell autoreactivity.
BACKGROUNDRolapitant, a novel neurokinin‐1 receptor antagonist, provided effective protection against chemotherapy‐induced nausea and vomiting (CINV) in a randomized, double‐blind phase 3 trial of patients receiving moderately emetogenic chemotherapy or an anthracycline and cyclophosphamide regimen. The current analysis explored the efficacy and safety of rolapitant in preventing CINV in a subgroup of patients receiving carboplatin.METHODSPatients were randomized 1:1 to receive oral rolapitant (180 mg) or a placebo 1 to 2 hours before chemotherapy administration; all patients received oral granisetron (2 mg) on days 1 to 3 and oral dexamethasone (20 mg) on day 1. A post hoc analysis examined the subgroup of patients receiving carboplatin in cycle 1. The efficacy endpoints were as follows: complete response (CR), no emesis, no nausea, no significant nausea, complete protection, time to first emesis or use of rescue medication, and no impact on daily life.RESULTSIn the subgroup administered carboplatin‐based chemotherapy (n = 401), a significantly higher proportion of patients in the rolapitant group versus the control group achieved a CR in the overall phase (0‐120 hours; 80.2% vs 64.6%; P < .001) and in the delayed phase (>24‐120 hours; 82.3% vs 65.6%; P < .001) after chemotherapy administration. Superior responses were also observed by the measures of no emesis, no nausea, and complete protection in the overall and delayed phases and by the time to first emesis or use of rescue medication. The incidence of treatment‐emergent adverse events was similar for the rolapitant and control groups.CONCLUSIONSRolapitant provided superior CINV protection to patients receiving carboplatin‐based chemotherapy in comparison with the control. These results support rolapitant use as part of the antiemetic regimen in carboplatin‐treated patients. Cancer 2016;122:2418–2425. © 2016 American Cancer Society.
Rolapitant, a selective and long-acting neurokinin-1 receptor antagonist, is approved in an oral formulation for the prevention of delayed chemotherapy-induced nausea and vomiting in adults. The objective of this pivotal study was to assess the bioequivalence of a single intravenous infusion of rolapitant versus a single oral dose of rolapitant. In this randomized, open-label phase 1 study, healthy volunteers were administered rolapitant as a 180-mg oral dose or a 30-minute 166.5-mg intravenous infusion. Blood samples for pharmacokinetic analysis were collected predose and at points up to 912 hours postdose. Criteria for bioequivalence of the intravenous dose versus the oral dose were met if the 90% confidence intervals (CIs) for the ratios of the geometric least-squares means (GLSMs) for the area under the plasma concentration-time curve (AUC) from time 0 to the time of the last quantifiable concentration (AUC ) and AUC from time 0 extrapolated to infinity (AUC ) for rolapitant were within 0.80-1.25. Mean rolapitant systemic exposure and half-lives were similar in the oral (n = 62) and intravenous (n = 61) rolapitant groups. The 90%CIs of the ratio of GLSMs were within the 0.80-1.25 range for AUC (0.94-1.09) and AUC (0.93-1.10). The incidence of treatment-emergent adverse events, all mild or moderate in severity, was similar in the intravenous and oral groups. A 166.5-mg intravenous infusion of rolapitant met the bioequivalence criteria based on AUC to a 180-mg oral dose and was well tolerated.
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