The Experts below are selected from a list of 132 Experts worldwide ranked by ideXlab platform
Armond S. Goldman - One of the best experts on this subject based on the ideXlab platform.
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Evolution of the Mammary Gland Defense System and the Ontogeny of the Immune System
Journal of Mammary Gland Biology and Neoplasia, 2002Co-Authors: Armond S. GoldmanAbstract:A decisive event in the evolution of mammals from synapsid reptiles was the modification of ventral thoracic–abdominal epidermal glands to form the mammary gland. The natural selection events that drove the process may have been the provision of certain immunological agents in dermal secretions of those nascent mammals. This is mirrored by similar innate immune factors in mammalian sebum and in protherian and eutherian milks. On the basis of studies of existing mammalian orders, it is evident that immune agents in milk such as immunoglobulins, Iron-Binding Proteins, lysozyme, oligosaccharides, and leukocytes compensate for developmental delays in early postnatal production of antimicrobial factors. At least in human milk, anti-inflammatory and immunomodulating agents also evolved to provide different types of protection for the offspring. In addition, investigations reveal that the types or concentrations of immunological agents in milk vary depending upon the type of placenta, lactation pattern, and environment of the species.
Hung Dae Sohn - One of the best experts on this subject based on the ideXlab platform.
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Expression profile of the Iron-Binding Proteins transferrin and ferritin heavy chain subunit in the bumblebee Bombus ignitus
Comparative Biochemistry and Physiology B, 2009Co-Authors: Hyung Joo Yoon, Jianhong Li, Hung Dae SohnAbstract:Abstract The Iron-Binding Proteins, transferrin and ferritin, are involved in the processes of transport and storage in iron metabolism. Their expression is induced in response to iron overload. Here, we show the expression profile of transferrin ( Bi-Tf ) and the ferritin heavy chain subunit ( Bi-FerHCH ) of the bumblebee Bombus ignitus in response to iron overload. Bi-Tf exhibits fat body-specific expression, whereas Bi-FerHCH is ubiquitously expressed and upregulated in various tissues, though in a similar manner, by iron overload. We also demonstrate their expression regulation via reduction of Bi-Tf or Bi-FerHCH levels in the fat body via RNA interference (RNAi). Under uniform conditions in which FeCl 3 was overloaded, the RNAi-induced Bi-Tf knock-down B. ignitus worker bees showed upregulated expression of Bi-FerHCH , and reciprocally, Bi-FerHCH RNAi knockdowns showed upregulated Bi-Tf expression in the fat body. This result indicates that, in case of the loss of Bi-Tf or Bi-FerHCH, the expression of Bi-FerHCH or Bi-Tf, respectively, is upregulated in response to iron overload.
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Molecular characterization of iron binding Proteins, transferrin and ferritin heavy chain subunit, from the bumblebee Bombus ignitus
Comparative Biochemistry and Physiology B, 2008Co-Authors: Dong Wang, Hyung Joo Yoon, Wei Lu, Hung Dae SohnAbstract:Abstract Transferrin and ferritin are Iron-Binding Proteins involved in transport and storage of iron as part of iron metabolism. Here, we describe the cDNA cloning and characterization of transferrin (Bi-Tf) and the ferritin heavy chain subunit (Bi-FerHCH), from the bumblebee Bombus ignitus. Bi-Tf cDNA spans 2340 bp and encodes a protein of 706 amino acids and Bi-FerHCH cDNA spans 1393 bp and encodes a protein of 217 amino acids. Comparative analysis revealed that Bi-Tf appears to have residues comprising Iron-Binding sites in the N-terminal lobe, and Bi-FerHCH contains a 5'UTR iron-responsive element and seven conserved amino acid residues associated with a ferroxidase center. The Bi-Tf and Bi-FerHCH cDNAs were expressed as 79 kDa and 27 kDa polypeptides, respectively, in baculovirus-infected insect Sf9 cells. Northern blot analysis revealed that Bi-Tf exhibits fat body-specific expression and Bi-FerHCH shows ubiquitous expression. The expression profiles of the Bi-Tf and Bi-FerHCH in the fat body of B. ignitus worker bees revealed that Bi-Tf and Bi-FerHCH are differentially induced in a time-dependent manner in a single insect by wounding, bacterial challenge, and iron overload.
John D. Kemp - One of the best experts on this subject based on the ideXlab platform.
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The role of iron and iron binding Proteins in lymphocyte physiology and pathology
Journal of Clinical Immunology, 1993Co-Authors: John D. KempAbstract:Knowledge concerning the roles of iron and iron binding Proteins in lymphocyte physiology and pathology has developed rapidly over the last few years. The genes for the major iron binding Proteins have been cloned and sequenced and are now being studied with respect to transcriptional and posttranscriptional regulatory mechanisms. T cells, B cells, macrophages, and natural killer cells appear to differ from one another in the ways in which they synthesize and utilize iron binding Proteins and in the amount of iron they take up and store. This suggests that differential modulation of iron-dependent metabolic functions is an intrinsic part of the distinctive physiology of each cellular component of the immune system and that the distribution of iron between those components is a carefully managed facet of the immune response. Since the immune response does not seem to be dramatically impaired by alterations in iron supplies that adversely affect other organs, it may well be that the cells of the immune system are especially adapted to have both high-priority access to iron when supply is low and high-level protection against iron-related toxicity when supply is in excess.
Hyung Joo Yoon - One of the best experts on this subject based on the ideXlab platform.
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Expression profile of the Iron-Binding Proteins transferrin and ferritin heavy chain subunit in the bumblebee Bombus ignitus
Comparative Biochemistry and Physiology B, 2009Co-Authors: Hyung Joo Yoon, Jianhong Li, Hung Dae SohnAbstract:Abstract The Iron-Binding Proteins, transferrin and ferritin, are involved in the processes of transport and storage in iron metabolism. Their expression is induced in response to iron overload. Here, we show the expression profile of transferrin ( Bi-Tf ) and the ferritin heavy chain subunit ( Bi-FerHCH ) of the bumblebee Bombus ignitus in response to iron overload. Bi-Tf exhibits fat body-specific expression, whereas Bi-FerHCH is ubiquitously expressed and upregulated in various tissues, though in a similar manner, by iron overload. We also demonstrate their expression regulation via reduction of Bi-Tf or Bi-FerHCH levels in the fat body via RNA interference (RNAi). Under uniform conditions in which FeCl 3 was overloaded, the RNAi-induced Bi-Tf knock-down B. ignitus worker bees showed upregulated expression of Bi-FerHCH , and reciprocally, Bi-FerHCH RNAi knockdowns showed upregulated Bi-Tf expression in the fat body. This result indicates that, in case of the loss of Bi-Tf or Bi-FerHCH, the expression of Bi-FerHCH or Bi-Tf, respectively, is upregulated in response to iron overload.
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Molecular characterization of iron binding Proteins, transferrin and ferritin heavy chain subunit, from the bumblebee Bombus ignitus
Comparative Biochemistry and Physiology B, 2008Co-Authors: Dong Wang, Hyung Joo Yoon, Wei Lu, Hung Dae SohnAbstract:Abstract Transferrin and ferritin are Iron-Binding Proteins involved in transport and storage of iron as part of iron metabolism. Here, we describe the cDNA cloning and characterization of transferrin (Bi-Tf) and the ferritin heavy chain subunit (Bi-FerHCH), from the bumblebee Bombus ignitus. Bi-Tf cDNA spans 2340 bp and encodes a protein of 706 amino acids and Bi-FerHCH cDNA spans 1393 bp and encodes a protein of 217 amino acids. Comparative analysis revealed that Bi-Tf appears to have residues comprising Iron-Binding sites in the N-terminal lobe, and Bi-FerHCH contains a 5'UTR iron-responsive element and seven conserved amino acid residues associated with a ferroxidase center. The Bi-Tf and Bi-FerHCH cDNAs were expressed as 79 kDa and 27 kDa polypeptides, respectively, in baculovirus-infected insect Sf9 cells. Northern blot analysis revealed that Bi-Tf exhibits fat body-specific expression and Bi-FerHCH shows ubiquitous expression. The expression profiles of the Bi-Tf and Bi-FerHCH in the fat body of B. ignitus worker bees revealed that Bi-Tf and Bi-FerHCH are differentially induced in a time-dependent manner in a single insect by wounding, bacterial challenge, and iron overload.
Nigel J. Saunders - One of the best experts on this subject based on the ideXlab platform.
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Host Iron Binding Proteins Acting as Niche Indicators for Neisseria meningitidis
PLOS ONE, 2009Co-Authors: Philip W. Jordan, Nigel J. SaundersAbstract:Neisseria meningitidis requires iron, and in the absence of iron alters its gene expression to increase iron acquisition and to make the best use of the iron it has. During different stages of colonization and infection available iron sources differ, particularly the host Iron-Binding Proteins haemoglobin, transferrin, and lactoferrin. This study compared the transcriptional responses of N. meningitidis, when grown in the presence of these iron donors and ferric iron, using microarrays. Specific transcriptional responses to the different iron sources were observed, including genes that are not part of the response to iron restriction. Comparisons between growth on haemoglobin and either transferrin or lactoferrin identified changes in 124 and 114 genes, respectively, and 33 genes differed between growth on transferrin or lactoferrin. Comparison of gene expression from growth on haemoglobin or ferric iron showed that transcription is also affected by the entry of either haem or ferric iron into the cytoplasm. This is consistent with a model in which N. meningitidis uses the relative availability of host iron donor Proteins as niche indicators. Growth in the presence of haemoglobin is associated with a response likely to be adaptive to survival within the bloodstream, which is supported by serum killing assays that indicate growth on haemoglobin significantly increases survival, and the response to lactoferrin is associated with increased expression of epithelial cell adhesins and oxidative stress response molecules. The transferrin receptor is the most highly transcribed receptor and has the fewest genes specifically induced in its presence, suggesting this is the favoured iron source for the bacterium. Most strikingly, the responses to haemoglobin, which is associated with unrestricted growth, indicates a low iron transcriptional profile, associated with an aggressive phenotype that may be adaptive to access host iron sources but which may also underlie the lethal features of meningococcal septicaemia, when haemoglobin may become a major source of iron.
