Publications by authors named "Lalit Kumar Dubey"

Eosinophils are involved in host protection against multicellular organisms. However, their recruitment to the mesenteric lymph node (mLN) during type 2 immunity is understudied. Our results demonstrate that eosinophil association with lymphoid stromal niches constructed by fibroblastic reticular cells (FRCs) and lymphatic endothelial cells is diminished in mice selectively lacking interleukin (IL)-4Rα or lymphotoxin-β (LTβ) expression on B cells.

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The meningeal space is a critical brain structure providing immunosurveillance for the central nervous system (CNS), but the impact of infections on the meningeal immune landscape is far from being fully understood. The extracellular protozoan parasite Trypanosoma brucei, which causes human African trypanosomiasis (HAT) or sleeping sickness, accumulates in the meningeal spaces, ultimately inducing severe meningitis and resulting in death if left untreated. Thus, sleeping sickness represents an attractive model to study immunological dynamics in the meninges during infection.

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Article Synopsis
  • The lymphatic system is essential for the immune response against intracellular pathogens but also aids cancer cell spread, and its role in mucocutaneous leishmaniasis (MCL) has not been fully explored.
  • Recent findings show that in cases of MCL, particularly when inflammation and viral endosymbionts are present, lymphatic vessels help infected cells escape from the initial infection site and spread to other organs.
  • Researchers used various methods to verify that parasites can move through migrating immune cells and lymphatic systems, leading to new infections in distant areas, highlighting the complex pathways of parasite dissemination.
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Adaptive type 2 immune responses against the intestinal helminth Heligmosomoides polygyrus (Hp) require the interaction of follicle-associated CXCR5 dendritic cells with naive T cells in the draining mesenteric lymph nodes (mLNs). However, the source of CXCL13 responsible for attracting CXCR5 dendritic cells has remained unclear. Using multiplex imaging combined with deep tissue analysis, we observed new CXCL13 fibroblastic reticular cells surrounding paracortical and cortical B cell follicles in the mLNs of infected mice.

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Multi-user core microscopy facilities are often faced with the challenge to adapt or modify existing instruments. This is essential in order to fulfill the requirements of the user community, who wants to image a wide range of model organisms with varying stains and sample thicknesses. In recent years, lightsheet microscopy has turned into an invaluable tool for both live and cleared sample imaging of many different specimens.

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() is a ubiquitous fungus of clinical importance associated with development of various pulmonary diseases and allergic hypersensitivity reactions. It is protected against environmental stress by a cell wall that contains polysaccharides such as chitin. We previously demonstrated that fibrinogen C domain-containing protein 1 (FIBCD1) is a membrane-bound protein that binds chitin through a conserved S1 binding site and is expressed in intestinal epithelium and salivary glands.

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Lymphatic growth (lymphangiogenesis) within lymph nodes functions to promote dendritic cell entry and effector lymphocyte egress in response to infection or inflammation. Here we demonstrate a crucial role for lymphotoxin-beta receptor (LTβR) signaling to fibroblastic reticular cells (FRCs) by lymphotoxin-expressing B cells in driving mesenteric lymph node lymphangiogenesis following helminth infection. LTβR ligation on fibroblastic reticular cells leads to the production of B-cell-activating factor (BAFF), which synergized with interleukin-4 (IL-4) to promote the production of the lymphangiogenic factors, vascular endothelial growth factors (VEGF)-A and VEGF-C, by B cells.

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Secondary lymphoid tissues provide specialized niches for the initiation of adaptive immune responses and undergo a remarkable expansion in response to inflammatory stimuli. Although the formation of B cell follicles was previously thought to be restricted to the postnatal period, we observed that the draining mesenteric lymph nodes (mLN) of helminth-infected mice form an extensive number of new, centrally located, B cell follicles in response to IL-4Rα-dependent inflammation. IL-4Rα signaling promoted LTα1β2 (lymphotoxin) expression by B cells, which then interacted with CCL19 positive stromal cells to promote lymphoid enlargement and the formation of germinal center containing B cell follicles.

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Intestinal helminths are potent regulators of their host's immune system and can ameliorate inflammatory diseases such as allergic asthma. In the present study we have assessed whether this anti-inflammatory activity was purely intrinsic to helminths, or whether it also involved crosstalk with the local microbiota. We report that chronic infection with the murine helminth Heligmosomoides polygyrus bakeri (Hpb) altered the intestinal habitat, allowing increased short chain fatty acid (SCFA) production.

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Helminth infections are typically chronic in nature; however, the exact molecular mechanisms by which these parasites promote or thwart host immunity remain unclear. Worm expulsion requires the differentiation of CD4(+) T cells into Th2 cells, while regulatory T cells (Tregs) act to dampen the extent of the Th2 response. Priming of T cells requires drainage or capture of antigens within lymphoid tissues, and in the case of intestinal helminths, such sites include the mucosa-associated Peyer's patches (PPs) and the draining mesenteric lymph nodes (MLN).

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Aspergillus fumigatus (A. fumigatus) is a ubiquitous fungus that activates, suppresses or modulates the immune response by changing its cell wall structure and by secreting proteases. In this study, we show that chitin acts as an adjuvant in a murine model of A.

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Chitin and β-glucan are conserved throughout evolution in the fungal cell wall and are the most common polysaccharides in fungal species. Together, these two polysaccharides form a structural scaffold that is essential for the survival of the fungus. In the present study, we demonstrated that Aspergillus fumigatus alkali-insoluble cell wall fragments (AIF), composed of chitin linked covalently to β-glucan, induced enhanced immune responses when compared with individual cell wall polysaccharides.

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