RESUMO
OBJECTIVE: Neutralizing antibodies (NAbs) occur in a proportion of multiple sclerosis (MS) patients treated with interferon (IFN)-beta. NAbs impair the effect of treatment. The biological effect of IFN-beta can be measured as the induction of the myxovirus resistance protein A (MxA) molecule. However, other markers could be more sensitive for evaluating the response to IFN-beta. We used DNA array analysis to identify genes that are strongly induced in blood cells by IFN-beta, and measured their expression in MS patients with different NAb levels. METHODS: Gene expression was studied on DNA arrays in untreated patients, in NAb negative patients, and in MS patients with varying NAb levels 9-12 h and 36-48 h after IFN-beta administration. The expression of selected genes was measured by real-time PCR. NAb levels were assessed by a cytopathic effect assay. RESULTS: Several hundred genes were induced 9-12 h after an injection of IFN-beta. The molecules CXCL10, CCL2 and IFI27 were among the most strongly induced. Gene induction was generally much less pronounced after 36-48 h, but IFI27 remained strongly induced. The strong induction of these molecules and MxA was confirmed by real-time PCR. Induction of MxA, CCL2, CXCL10 and IFI27 was reduced in patients with low NAb levels and lost in patients with intermediate/high NAb levels. CONCLUSION: We identify IFI27, CCL2 and CXCL10 as sensitive biomarkers for the response to IFN-beta. The expression of these markers adequately reflects bioactivity of IFN-ss as documented by the decreased induction in low NAb-positive patients and the lost induction in patients with moderate/high NAb levels.
Assuntos
Biomarcadores/análise , Resistência a Medicamentos/genética , Fatores Imunológicos/uso terapêutico , Interferon beta/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/genética , Anticorpos Neutralizantes/sangue , Quimiocina CCL2/biossíntese , Quimiocina CCL2/genética , Quimiocina CXCL10/biossíntese , Quimiocina CXCL10/genética , Expressão Gênica , Perfilação da Expressão Gênica , Humanos , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Esclerose Múltipla/sangue , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Treatment with interferon-beta (IFN-beta) induces the expression of hundreds of genes in blood mononuclear cells, and the expression of several genes has been proposed as a marker of the effect of treatment with IFN-beta. However, to date no molecules have been identified that are stably induced by treatment with IFN-beta. We use DNA microarrays to study gene expression in 10 multiple sclerosis (MS) patients who began de novo treatment with IFN-beta. After the first injection of IFN-beta, the expression of 74 out of 3428 genes changed at least two-fold and statistically significantly (after Bonferroni correction). In contrast, we observed no persisting effects of IFN-beta on gene expression. Among the most strongly induced genes was MXA, which has been used in previous biomarker studies in MS. In addition, the study identified the induction of LGALS9 and TCIR1G, involved in negative regulation of T helper type I immunity and T-cell activation, as novel effects of IFN-beta therapy in MS.