title: Macrophage cell death due to Salmonella enterica serovar Typhi and its acid stress protein has features of apoptosis.
abstract: Salmonella spp. have been shown to cause apoptosis of various host cell types as a part of their infection process. However, the induction of apoptosis remains to be looked into under the different host environments including acidic stress experienced by the pathogen. In order to simulate the in vivo acidic conditions, we studied the potential of S. typhi and its protein expressed under in vitro acidic conditions to induce apoptosis in macrophages. Murine macrophages were isolated and interacted with serovar Typhi and its acid stress protein for different time periods. The assessment of nucleosomal DNA, and nuclear staining with H-33342 dye and flow cytometry indicated the occurrence of characteristic features of apoptosis. Analysis of data revealed that S. typhi caused apoptotic cell death in 61% of macrophages whereas stress-induced protein alone accounted for apoptotic cell death in 45% of macrophages. The present study, for the first time demonstrates the potential of stress-induced outermembrane component of S. typhi to induce apoptosis. Identification of such factors may offer new insights for understanding the pathophysiology of the disease during the host-pathogen interactions.
authors.affiliation: Department of Microbiology, Panjab University, Chandigarh, India.
authors.forename: Harish
authors.initials: H
authors.lastname: Chander
authors.forename: Siddarth
authors.initials: S
authors.lastname: Majumdar
authors.forename: Sunita
authors.initials: S
authors.lastname: Sapru
authors.forename: Praveen
authors.initials: P
authors.lastname: Rishi
mesh_terms: D000818:Animals; D017209:Apoptosis; D001425:Bacterial Outer Membrane Proteins / Q000633:toxicity*; D001562:Benzimidazoles; D002460:Cell Line; D004247:DNA / Q000032:analysis / Q000302:isolation & purification; D053938:DNA Fragmentation; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D006863:Hydrogen-Ion Concentration; D008264:Macrophages / Q000166:cytology* / Q000382:microbiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012485:Salmonella typhi / Q000472:pathogenicity*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001562:Benzimidazoles; D005456:Fluorescent Dyes; D004247:DNA; C017807:bisbenzimide ethoxide trihydrochloride