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Full-Text Articles in Microbiology

Membrane On The Frontier, Erin Wu, David Erickson Mar 2017

Membrane On The Frontier, Erin Wu, David Erickson

Journal of Undergraduate Research

Antimicrobial chemokines is a type of host defense protein that play an important role in the natural defenses of many organisms such as defending skin and mucosal tissues against bacterial infections.These peptides have a net positive charge, which contributes to membrane permeabilization and/or cell penetration. It has been observed that CCL28, an antimicrobial chemokine, binds to the surface of bacteria, however, it is not known how they bind, or what they do, to cause bacterial death. Research has demonstrated that Yersinia pseudo tuberculosis with mutations in lipopolysaccharide Oantigen and core synthesis genes (rfaD mutation) exhibit increased binding affinity for the …


The Role Of The Transcriptional Antiterminator Rfah In Lipopolysaccharide Synthesis, Resistance To Antimicrobial Peptides, And Virulence Of Yersinia Pseudotuberculosis And Yersinia Pestis, Jared Michael Hoffman Jun 2016

The Role Of The Transcriptional Antiterminator Rfah In Lipopolysaccharide Synthesis, Resistance To Antimicrobial Peptides, And Virulence Of Yersinia Pseudotuberculosis And Yersinia Pestis, Jared Michael Hoffman

Theses and Dissertations

RfaH is a unique bacterial protein that enhances transcription of a select group of long operons in many Gram-negative bacteria. Operons regulated by RfaH possess an upstream operon polarity suppressor sequence, which recruits the RfaH protein to the RNA polymerase during transcription of genes, most of which are involved in the synthesis of cell-surface features. These include synthesis of the lipopolysaccharide (LPS) core and O-antigen in Salmonella and Escherichia coli, as well as F-plasmid conjugation pilus and capsule in E. coli. LPS is an important virulence factor in many Gram-negative bacteria, and protects Y. pseudotuberculosis against host antimicrobial …


Partial Characterization Of The Antimicrobial Activity Of Ccl28, Bin Liu Feb 2012

Partial Characterization Of The Antimicrobial Activity Of Ccl28, Bin Liu

Theses and Dissertations

This research focuses on the antimicrobial activity of the mouse chemokine CCL28. In addition to their well characterized chemotactic activity, many chemokines have been shown to be antimicrobial in vitro, including the mucosally expressed chemokine CCL28. I have investigated the primary sequence features required for antimicrobial activity, salt sensitive nature of killing/binding mechanism, and in vivo microbial interactions of CCL28. Through the use of protein mutation and expression techniques, I have shown that the holoprotein (108 amino acids) is necessary for full antimicrobial activity of CCL28. Furthermore, the C terminal region of CCL28 is essential for microbial killing as an …


Specific Compartmentalization Of Iga Ascs In Mouse Salivary Glands Via Differential Expression Of Chemokines And Chemokine Receptors, Yuet Ching Law Nov 2008

Specific Compartmentalization Of Iga Ascs In Mouse Salivary Glands Via Differential Expression Of Chemokines And Chemokine Receptors, Yuet Ching Law

Theses and Dissertations

The mucosal system, which forms a barrier between internal organ systems and the external environment, is frequently exposed to pathogenic microorganisms. Immunoglobulin A (IgA) antibody secreting cells (ASCs) localize in the lamina propria, and produce IgA antibodies which help protect mucosal tissues. The concept of a common mucosal immune system in which IgA ASCs have the ability to populate any mucosal site has been proposed (1, 2). However, recent research has suggested that IgA ASCs primed in different mucosal sites might possess different sets of chemokine receptors, and therefore migrate specifically to particular mucosal locations (3). In this study, the …


The Role Of Prolactin In Ccl28 Regulation, Jennie Hyde Mar 2007

The Role Of Prolactin In Ccl28 Regulation, Jennie Hyde

Theses and Dissertations

Infants are born with naive immune systems, making them susceptible to a variety of infections. In order to protect the newborn infant it is important that mothers be able to pass protective IgA antibodies to their infants through breast milk. B cells that produce IgA enter the mammary tissue during lactation and secrete IgA into the milk. During pregnancy, the mammary tissue expresses high levels of chemokines, molecules that allow lymphocytes to selectively home to specific tissues. The chemokine CCL28 has been shown to be upregulated during both pregnancy and lactation, and is vital for the ability of IgA-producing B …