Salmonella pathogenesis
Anti-Salmonella immunity
Anti-Salmonella immunity: Highlighting new research in vaccines, mucosal immunology and systemic disease
from Jennifer L. Bishop, Ellen T. Arena, Kenneth W. Harder and B. Brett Finlay writing in Salmonella: From Genome to Function
Enteric fever and non-typhoidal salmonelloses (NTS) are caused by a wide variety of Salmonella enterica serovars and are a serious health threat throughout the world. Immunity to systemic typhoid and NTS requires intricate crosstalk between both innate and adaptive immune cells spanning multiple organ systems. The development of a number of new mouse and in vitro culture models suitable for studying gastroenteritis has highlighted the complexity of mucosal responses and shown how a diverse subset of cells interact within the intestinal architecture to elicit anti-Salmonella immunity. These include specific dendritic cell subsets, natural killer cells and TH17 skewed T helper cells and the repertoire of cytokines they produce, including IL-17, IL-23, IL-22 and IL-15. Furthermore, the importance of commensal microflora has been stressed in various Salmonella models, and new research has shown the various effects of prebiotics, probiotics and antibiotics on Salmonella pathogenesis. Systemic immune responses are also more explicitly understood, as the location and phenotype of cells harboring intracellular bacteria become more defined. A forthcoming book reviews these recent advances and how they are being translated into new therapies and vaccine studies in the human population.
Read more: Salmonella: From Genome to Function
from Jennifer L. Bishop, Ellen T. Arena, Kenneth W. Harder and B. Brett Finlay writing in Salmonella: From Genome to Function
Enteric fever and non-typhoidal salmonelloses (NTS) are caused by a wide variety of Salmonella enterica serovars and are a serious health threat throughout the world. Immunity to systemic typhoid and NTS requires intricate crosstalk between both innate and adaptive immune cells spanning multiple organ systems. The development of a number of new mouse and in vitro culture models suitable for studying gastroenteritis has highlighted the complexity of mucosal responses and shown how a diverse subset of cells interact within the intestinal architecture to elicit anti-Salmonella immunity. These include specific dendritic cell subsets, natural killer cells and TH17 skewed T helper cells and the repertoire of cytokines they produce, including IL-17, IL-23, IL-22 and IL-15. Furthermore, the importance of commensal microflora has been stressed in various Salmonella models, and new research has shown the various effects of prebiotics, probiotics and antibiotics on Salmonella pathogenesis. Systemic immune responses are also more explicitly understood, as the location and phenotype of cells harboring intracellular bacteria become more defined. A forthcoming book reviews these recent advances and how they are being translated into new therapies and vaccine studies in the human population.
Read more: Salmonella: From Genome to Function
Salmonella virulence factors
Salmonella secreted virulence factors
from Fred Heffron, George Niemann, Hyunjin Yoon, Afshan Kidwai, Roslyn Brown, Jason McDermott, Richard Smith and Joshua Adkins writing in Salmonella: From Genome to Function
Research in the past twenty years has shown that Salmonella precisely manipulates their host by hierarchical secretion of virulence factors (effectors). More than 40 secreted virulence factors have been identified in Salmonella, but the function and mammalian targets of only a few are known. Effectors are directed to specific sub-cellular compartments and mammalian targets, and they mediate a diverse array of activities. Thus, the first half of this review focuses upon our understanding of effector mechanisms and their roles during infection.
However, the known effector repertoire is incomplete and the second half of this review places an emphasis on discovery. Computer analysis identified common secretion motifs and predicted that as many as 300 additional proteins may be secreted by Salmonella. In fact, mass spectrometry analysis identified a more complete secretome and found many novel, uncharacterized effector proteins. Several effectors identified in this study were small proteins of only 30-100 amino acids in length, suggesting that they are not enzymes but agonists or antagonists of specific host factors. One surprise from the mass spectrometry analysis was the identification of proteins that are secreted to mammalian cells via outer membrane vesicles. Complete characterization of the bewildering array of secreted proteins will take many years.
Further reading: Salmonella: From Genome to Function | Bacterial Secreted Proteins
from Fred Heffron, George Niemann, Hyunjin Yoon, Afshan Kidwai, Roslyn Brown, Jason McDermott, Richard Smith and Joshua Adkins writing in Salmonella: From Genome to Function
Research in the past twenty years has shown that Salmonella precisely manipulates their host by hierarchical secretion of virulence factors (effectors). More than 40 secreted virulence factors have been identified in Salmonella, but the function and mammalian targets of only a few are known. Effectors are directed to specific sub-cellular compartments and mammalian targets, and they mediate a diverse array of activities. Thus, the first half of this review focuses upon our understanding of effector mechanisms and their roles during infection.
However, the known effector repertoire is incomplete and the second half of this review places an emphasis on discovery. Computer analysis identified common secretion motifs and predicted that as many as 300 additional proteins may be secreted by Salmonella. In fact, mass spectrometry analysis identified a more complete secretome and found many novel, uncharacterized effector proteins. Several effectors identified in this study were small proteins of only 30-100 amino acids in length, suggesting that they are not enzymes but agonists or antagonists of specific host factors. One surprise from the mass spectrometry analysis was the identification of proteins that are secreted to mammalian cells via outer membrane vesicles. Complete characterization of the bewildering array of secreted proteins will take many years.
Further reading: Salmonella: From Genome to Function | Bacterial Secreted Proteins