RESUMO
Prolonged existence of filarial parasites and their molecules within the host modulate the host immune system to instigate their survival and induce inflammatory responses that contribute to disease progression. Recombinant Brugia malayi pepsin inhibitor (rBm33) modulates the host immune responses by skewing towards Th1 responses characterized by secretion of inflammatory molecules such as TNF-α, IL-6, nitric oxide (NO). Here we also specified the molecular signaling events triggered by rBm33 in peripheral blood mononuclear cells (PBMCs) of filarial endemic normals (EN). rBm33 predominantly enhanced the levels of nitric oxide in cultured PBMCs but did not result in oxidative stress to the host cells. Further, rBm33 treatment of human PBMCs resulted in higher GSH/GSSG levels. MYD88 dependent activation was found to be associated with rBm33 specific inflammatory cytokine production. rBm33 triggered intracellular signaling events also involved JNK activation in host PBMCs. In addition, c-Fos and not NF-κB was identified as the transcription factor regulating the expression of inflammatory cytokines in rBm33 stimulated PBMCs. rBm33 marked its role in filarial pathology by altered levels of growth factors but did not have a significant impact on matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs) activity of host PBMCs. Thus, the study outlines the signaling network of rBm33 induced inflammatory responses within the host immune cells.
Assuntos
Antígenos de Helmintos/imunologia , Antígenos de Helmintos/metabolismo , Brugia Malayi/imunologia , Brugia Malayi/patogenicidade , Filariose Linfática/imunologia , Proteínas de Helminto/imunologia , Proteínas de Helminto/metabolismo , Inibidores de Proteases/metabolismo , Transdução de Sinais , Animais , Antígenos de Helmintos/genética , Brugia Malayi/genética , Brugia Malayi/metabolismo , Citocinas/metabolismo , Citoproteção/efeitos dos fármacos , Filariose Linfática/parasitologia , Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Proteínas de Helminto/genética , Interações Hospedeiro-Parasita/imunologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Interleucina-6/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/parasitologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Mitógenos , Óxido Nítrico/metabolismo , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Células Th1 , Inibidores Teciduais de Metaloproteinases/genética , Inibidores Teciduais de Metaloproteinases/metabolismo , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The effect of recombinant Brugia malayi pepsin inhibitor (rBm33) on human monocytes/macrophages has been examined using THP-1 cells. THP-1 cells stimulated with rBm33 showed enhanced levels of expression of pro-inflammatory cytokines (IL-1ß, TNF-α, IL-6) and diminished levels of IL-12, iNOS and anti-inflammatory cytokine (IL-10) expression suggesting the predominant features of Th1 response. Phorbol-12-myristate-13-acetate (PMA) treated THP-1 cells stimulated with rBm33 and subsequent incubation with GFP expressing Escherichia coli (E. coli) for 2 h enhanced the uptake of E. coli. Nitric oxide (NO) levels measured in the supernatants of these cultures did not show significant changes. Apoptotic studies with Peripheral Blood Mononuclear Cells (PBMCs) from normal individuals stimulated with rBm33 did not induce apoptosis of monocytes or lymphocytes. These observations suggest that rBm33 stimulates macrophages to induce Th1 response and does not promote apoptosis.