Macrophages play a critical role in innate immunity. Differentiation Ags present on macrophages such as CD14 orchestrate the first line of defense against infection. The basal/homeostatic signaling scheme that keeps macrophages thus groomed for innate immune functions remains unresolved. Wnt5a-Fz5 signaling being a primordial event during cell differentiation, we examined the involvement of Wnt5a-Fz5 signaling in the maintenance of innate immune functions. In this study, we demonstrate that innate immune functions of macrophages ensue at least partly through a homeostatic Wnt5a-Fz5-NF-kB (p65) circuit, which is Rac1 dependent. The autocrine/paracrine Wnt5a-Fz5-Rac1-p65 signaling cascade not only maintains basal levels of the immune defense modulating IFNs and CD14; it also supports macrophage survival. Wnt5a-Fz5-Rac1 signaling mediated p65 homeostasis in turn sustains Wnt5a expression in a feed-forward mode. The natural immune response of macrophages to Escherichia coli/LPS and virus is accordingly sustained. The depiction of sustenance of innate immune functions as an outcome of a homeostatic Wnt5a-p65 axis unfolds previously unidentified details of immune regulation and provides new insight into homeostatic cell signaling. The Journal of Immunology, 2014, 192: 4386-4397. © 2014 by The American Association of Immunologists, Inc.

D NASKAR

G MAITI

A CHAKRABORTY

A ROY

D CHATTOPADHYAY

M SEN

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Journal of Immunology

The phosphoprotein (P protein) of the chandipura virus (CHPV), a negative strand RNA virus, is involved in both transcription and replication of the viral life cycle. Interaction between the P protein and the viral leader (le) RNA under in vitro conditions has been previously reported for CHPV and other negative strand RNA viruses such as the rinderpest virus (RPV). However, till date, the region of the P protein involved in le RNA binding remains undefined. Moreover, the in vivo occurrence of this interaction has not been studied before. Here, we have characterised the P protein-le RNA interaction, using single tryptophan mutants of the P protein. The CHPV P protein contains two tryptophan residues located at amino acid position 105 and 135 respectively. Our previous study showed that Trp 135 is located in a buried region within a less polar environment whereas Trp 105 is more solvent-exposed. In this study we have used steady state and time resolved fluorescence spectroscopy at 298 K to show that the buried tryptophan (Trp 135) is involved in the interaction with the le RNA and the more solvent exposed Trp 105 is only slightly perturbed during this interaction. We also show that Trp 135 is responsible for the dimerization of the CHPV P protein. In addition, we have been able to demonstrate for the first time that the P protein-le RNA interaction is detectable in CHPV-infected Vero-76 cells and this interaction is augmented during the replication phase of the viral cycle. © 2012 Elsevier Masson SAS. All rights reserved.

Biochimie

Characterization of the chandipura virus leader RNA-phosphoprotein interaction using single tryptophan mutants and its detection in viral infected cells

Chandipura virus, a member of the rhabdoviridae family and vesiculovirus genera, has recently emerged as human pathogen that is associated with a number of outbreaks in different parts of India. Although, the virus closely resembles with the prototype vesiculovirus, Vesicular Stomatitis Virus, it could be readily distinguished by its ability to infect humans. Studies on Chandipura virus while shed light into distinct stages of viral infection; it may also allow us to identify potential drug targets for antiviral therapy. In this review, we have summarized our current understanding of Chandipura virus life cycle at the molecular detail with particular interest in viral RNA metabolisms, namely transcription, replication and packaging of viral RNA into nucleocapsid structure. Contemporary research on otherwise extensively studied family member Vesicular Stomatitis Virus has also been addressed to present a more comprehensive picture of vesiculovirus life cycle. Finally, we reveal examples of protein economy in Chandipura virus life-cycle whereby each viral protein has evolved complexity to perform multiple tasks. © 2007 The Biochemical Society.

Fulltext

Bioscience Reports

Reviewing chandipura: A vesiculovirus in human epidemics

Molecular Biology of the Cell

Wnt5a signaling promotes apical and basolateral polarization of single epithelial cells

BMC Infectious Diseases

Chandipura Virus infection in mice: the role of toll like receptor 4 in pathogenesis

Proceedings of the National Academy of Sciences

The Wingless homolog Wnt5a stimulates phagocytosis but not bacterial killing

Wnt5a-Rac1-NF-ÎºB homeostatic circuitry sustains innate immune functions in macrophages

Journal	Journal of Immunology
Publisher	American Association of Immunologists
ISSN	0022-1767