Autor(es): Abraham Rachy, Mudaliar Prashant, Padmanabhan Aiswaria, Sreekumar Easwaran

Resumo: Chikungunya virus (CHIKV), an arthritogenic old-world alphavirus, has been implicated in the central nervous system (CNS) infection in infants - elderly patients. Astrocytes are the major immune cells of the brain parenchyma that mediate inflammation. In the present study we found that a local isolate of CHIKV infect - activate U-87 MG cells, a glioblastoma cell line of human astrocyte origin. The infection kinetics were similar in infected U-87 MG cells - the human embryo kidney (HEK293) cells as indicated by immunofluorescence - plaque assays, 24h post-infection (p.i.). In infected U-87 MG cells, apoptosis was detectable from 48h p.i. evidenced by DNA fragmentation, PARP cleavage, loss of mitochondrial membrane potential, nuclear condensation - visible cytopathic effects in a dose - time-dependent manner. XBP1 mRNA splicing - eIF2? phosphorylation studies indicated the occurrence of endoplasmic reticulum stress in infected cells. In U-87 MG cells stably expressing a green fluorescent protein-tagged light chain-3 (GFP-LC3) protein, CHIKV infection showed increased autophagy response. The infection led to an enhanced expression of the mRNA transcripts of the pro-inflammatory cytokines IL-1?, TNF-?, IL-6 - CXCL9 within 24h p.i. Significant up-regulation of the proteins of RIG-I like receptor (RLR) pathway, such as RIG-I - TRAF-6, was observed indicating the activation of the cytoplasmic-cellular innate immune response. The overall results show that the U-87 MG cell line is a potential in vitro model for in depth study of these molecular pathways in response to CHIKV infection. The responses in these cells of CNS origin, which are inherently defective in Type I interferon response, could be analogous to that occurring in infants - very old patients who also have a compromised interferon-response. The results also point to the intriguing possibility of using this virus for studies to develop oncolytic virus therapy approaches against glioblastoma, a highly aggressive malignancy.

Imprenta: PloS One, v. 8, n. 9, p. e75854, 2013

Identificador do objeto digital: 10.1371/journal.pone.0075854

Descritores: Chikungunya virus - Biosynthesis ; Chikungunya virus - Cell ; Chikungunya virus - DNA ; Chikungunya virus - Immune response ; Chikungunya virus - Pathogenesis ; Chikungunya virus - Proteins ; Chikungunya virus - Cytokines ; Chikungunya virus - Immune response ; Chikungunya virus - Inflammation ; Chikungunya virus - Molecular methods ; Chikungunya Virus - Virus

Data de publicação: 2013

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