In JoVE (1)
Articles by Sarita Ahlawat in JoVE
Isolating And Immunostaining Lymphocytes and Dendritic Cells from Murine Peyer's Patches Magdia De Jesus1, Sarita Ahlawat1, Nicholas J. Mantis1 1Division of Infectious Diseases, New York State Department of Health There is an increasing interest in understanding the immunological functions of specific subpopulations of cells in Peyer's patches (PPs), the primary inductive sites of gut-associated lymphoid tissues. Here we outline parallel protocols for preparing PP single cell preparations for flow cytometric analysis and PP cryosections for immunostaining.
Other articles by Sarita Ahlawat on PubMed
ClpXP Degrades SsrA-tagged Proteins in Streptococcus Pneumoniae Journal of Bacteriology. Apr, 2009 | Pubmed ID: 19218384 Bacterial proteins that are abnormally truncated due to incomplete mRNA or the presence of rare codons are extended by an SsrA tag during ribosome rescue in a trans-translation process important for maintaining protein quality. In Escherichia coli, the SsrA-tagged proteins become the target of the Tsp, Lon, FtsH, ClpXP, and ClpAP proteases. Here we show that degradation of model SsrA-tagged proteins in Streptococcus pneumoniae depends primarily or exclusively on ClpXP in vivo. In addition, we show the E. coli SsrA tag is also a target of S. pneumoniae ClpXP in vivo, even though the N-terminal portions of the tags differ significantly between the two species, suggesting there may be no adaptor protein for SsrA in S. pneumoniae.
Identification of Small Molecules That Suppress Ricin-induced Stress-activated Signaling Pathways PloS One. 2012 | Pubmed ID: 23133670 Ricin is a member of the ribosome-inactivating protein (RIP) family of plant and bacterial toxins. In this study we used a high-throughput, cell-based assay to screen more than 118,000 compounds from diverse chemical libraries for molecules that reduced ricin-induced cell death. We describe three compounds, PW66, PW69, and PW72 that at micromolar concentrations significantly delayed ricin-induced cell death. None of the compounds had any demonstrable effect on ricin's ability to arrest protein synthesis in cells or on ricin's enzymatic activity as assessed in vitro. Instead, all three compounds appear to function by blocking downstream stress-induced signaling pathways associated with the toxin-mediated apoptosis. PW66 virtually eliminated ricin-induced TNF-Î± secretion by J774A.1 macrophages and concomitantly blocked activation of the p38 MAPK and JNK signaling pathways. PW72 suppressed ricin-induced TNF-Î± secretion, but not p38 MAPK and JNK signaling. PW69 suppressed activity of the executioner caspases 3/7 in ricin toxin- and Shiga toxin 2-treated cells. While the actual molecular targets of the three compounds have yet to be identified, these data nevertheless underscore the potential of small molecules to down-regulate inflammatory signaling pathways associated with exposure to the RIP family of toxins.