Publications by authors named "Ramneek Johal"

Due to its ubiquity and versatility in the human body, collagen is an ideal base material for tissue-engineering constructs. Chemical crosslinking treatments allow precise control of the biochemical and mechanical properties through macromolecular modifications to the structure of collagen. In this work, three key facets regarding the collagen crosslinking process are explored.

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Allergens are initiators of both innate and adaptive immune responses. They are recognised at the site of entry by epithelial and dendritic cells (DCs), both of which activate innate inflammatory circuits that can collectively induce Th2 immune responses. In an attempt to have a better understanding of the role of carbohydrates in the recognition and uptake of allergens by the innate immune system, we defined common glycosylation patterns in major allergens.

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Uniform cellular distribution is a prerequisite to forming tissue within porous scaffolds, but the seeding process often results in preferential adhesion of cells at the periphery. We develop a vapour phase coating strategy which is readily applicable to any porous solid to provide a uniform cellular distribution. Plasma polymerized allyl amine (ppAAm) is used to form a thin nitrogen-containing coating throughout porous three-dimensional (3-D) poly(d,l-lactic acid) scaffolds.

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Confocal Raman micro-spectroscopy (CRMS) was used to measure spectral images of immunological synapse formation between dendritic and T cells without using molecular labels or other invasive procedures. The purpose-built inverted CRMS instrument integrated an environmental enclosure and a near-infrared laser to allow measurements on live cells maintained under physiological conditions. The integration of the wide-field fluorescence also enabled viability assays and direct comparison between Raman spectral images and gold-standard immuno-fluorescence images for specific molecules.

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Background: Sampling the microenvironment at sites of microbial exposure by dendritic cells (DC) and their subsequent interaction with T cells in the paracortical area of lymph nodes are key events for initiating immune responses. Most of our knowledge of such events in human is based on in vitro studies performed in the absence of extracellular matrix (ECM) proteins. ECM in basement membranes and interstitial spaces of different tissues, including lymphoid organs, plays an important role in controlling specific cellular functions such as migration, intracellular signalling and differentiation.

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The NF-kappaB family of transcription factors is vital to all aspects of immune function and regulation in both the hemopoietic and stromal compartments of immune environments. Recent studies of mouse models deficient for specific members of the NF-kappaB family have revealed critical roles for these proteins in the process of secondary lymphoid tissue organogenesis. In this study, we investigate the role of NF-kappaB family member NF-kappaB2 in lymph node development and lymphocyte recruitment.

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