Tamoutounour S.,Aix - Marseille University |
Tamoutounour S.,French Institute of Health and Medical Research |
Tamoutounour S.,French National Center for Scientific Research |
Henri S.,Aix - Marseille University |
And 28 more authors.
European Journal of Immunology | Year: 2012
Dendritic cells (DCs) and monocyte-derived macrophages (MΦs) are key components of intestinal immunity. However, the lack of surface markers differentiating MΦs from DCs has hampered understanding of their respective functions. Here, we demonstrate that, using CD64 expression, MΦs can be distinguished from DCs in the intestine of both mice and humans. On that basis, we revisit the phenotype of intestinal DCs in the absence of contaminating MΦs and we delineate a developmental pathway in the healthy intestine that leads from newly extravasated Ly-6Chi monocytes to intestinal MΦs. We determine how inflammation impacts this pathway and show that T cell-mediated colitis is associated with massive recruitment of monocytes to the intestine and the mesenteric lymph node (MLN). There, these monocytes differentiate into inflammatory MΦs endowed with phagocytic activity and the ability to produce inducible nitric oxide synthase. In the MLNs, inflammatory MΦs are located in the T-cell zone and trigger the induction of proinflammatory T cells. Finally, T cell-mediated colitis develops irrespective of intestinal DC migration, an unexpected finding supporting an important role for MLN-resident inflammatory MΦs in the etiology of T cell-mediated colitis. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Murillo M.M.,Cancer Research UK Research Institute |
Murillo M.M.,Institute of Cancer Research |
Zelenay S.,Immunobiology Laboratory |
Nye E.,Experimental Histopathology Laboratory |
And 5 more authors.
Journal of Clinical Investigation | Year: 2014
Direct interaction of RAS with the PI3K p110α subunit mediates RAS-driven tumor development: however, it is not clear how p110α/RAS- dependant signaling mediates interactions between tumors and host tissues. Here, using a murine tumor cell transfer model, we demonstrated that disruption of the interaction between RAS and p110α within host tissue reduced tumor growth and tumor-induced angiogenesis, leading to improved survival of tumor-bearing mice, even when this interaction was intact in the transferred tumor. Furthermore, functional interaction of RAS with p110α in host tissue was required for efficient establishment and growth of metastatic tumors. Inhibition of RAS and p110α interaction prevented proper VEGF-A and FGF-2 signaling, which are required for efficient angiogenesis. Additionally, disruption of the RAS and p110α interaction altered the nature of tumor-associated macrophages, inducing expression of markers typical for macrophage populations with reduced tumor-promoting capacity. Together, these results indicate that a functional RAS interaction with PI3K p110α in host tissue is required for the establishment of a growth-permissive environment for the tumor, particularly for tumor-induced angiogenesis. Targeting the interaction of RAS with PI3K has the potential to impair tumor formation by altering the tumorhost relationship, in addition to previously described tumor cell-autonomous effects.
Ghosh P.,Immunobiology Laboratory |
Mukherjee N.,Immunobiology Laboratory |
Ghosh K.,Immunobiology Laboratory |
Mallick S.,West Bengal State University |
And 3 more authors.
Indian Journal of Experimental Biology | Year: 2015
The monocytic lineage cells in brain, generally speaking brain macrophage and/or microglia show some dissimilar distribution patterns and disagreement regarding their origin and onset in brain. Here, we investigated its onset and distribution/colonization pattern in normal brain with development. Primarily, early and late embryonic stages, neonate and adult brains were sectioned for routine H/E staining; a modified silver-gold staining was used for discriminating monocytic lineage cells in brain; and TEM to deliver ultramicroscopic details of these cells in brain. Immunofluorescence study with CD11b marker revealed the distribution of active microglia/macrophage like cells. Overall, in early embryonic day 12, the band of densely stained cells are found at the margin of developing ventricles and cells sprout from there dispersed towards the outer edge. However, with development, this band shrunk and the dispersion trend decreased. The deeply stained macrophage like cell population migration from outer cortex to ventricle observed highest in late embryonic days, continued with decreased amount in neonates and settled down in adult. In adult, a few blood borne macrophage like cells were observed through the vascular margins. TEM study depicted less distinguishable features of cells in brain in early embryo, whereas from late embryo to adult different neuroglial populations and microglia/macrophages showed distinctive features and organization in brain. CD11b expression showed some similarity, though not fully, with the distribution pattern depending on the differentiation/activation status of these macrophage lineage cells. This study provides some generalized spatial and temporal pattern of macrophage/microglia distribution in rat brain, and further indicates some intrigue areas that need to be addressed. © 2015, National Institute of Science Communication. All rights reserved.
Ghosh K.,Immunobiology Laboratory |
Ghosh S.,Bangur Institute of Neurosciences |
Chatterjee U.,SSKM Hospital |
Ghosh A.,Immunobiology Laboratory
Asian Pacific Journal of Cancer Prevention | Year: 2016
Human glioma, arising from glial cells of the central nervous system, accounts for almost 30%of all brain tumours , neoplasms with a poor prognosis and high mortality rates worldwide. In the present study we assessed tissue architectural modifications associated with macrophage lineage cells, controversial major immune effector cells within the brain, in human glioma tissue samples from eastern India. Ethically cleared post-operative human glioma samples from our collaborative neurosurgery unit with respective CT/MRI and patient history were collected from the Nodal Centre of Neurosciences in Kolkata, over 9 months. Along with conventional histopathology, samples were subjected to silver-gold staining and fluorescence tagged immunophenotyping for the detection of electron dense brain macrophage/microglia cells in glioma tissue, followed by immune-phenotyping of cells. With higher grades, CD11b+/Iba-1+ macrophage/microglia architecture with de-structured boundaries of glioma lesions indicated malfunction and invasive effector state. Present study documented a contribution of microglia to glioma progression in Eastern India.