The Precision nEDM Measurement with UltraCold Neutrons at TRIUMF

The TRIUMF Ultra-Cold Advanced Neutron (TUCAN) collaboration aims at a precision neutron electric dipole moment (nEDM) measurement with an uncertainty of $10^{-27}\,e\cdot\mathrm{cm}$, which is an order-of-magnitude better than the current nEDM upper limit and enables us to test Supersymmetry. To achieve this precision, we are developing a new high-intensity ultracold neutron (UCN) source using super-thermal UCN production in superfluid helium (He-II) and a nEDM spectrometer. The current development status of them is reported in this article.Comment: Proceedings of the 24th International Spin Symposium (SPIN 2021), 18-22 October 2021, Matsue, Japa

Molecular analysis of Haemophilus influenzae hemagglutinating pili.

Haemophilus influenzae colonizes the upper respiratory tract of humans and is the etiologic agent of various mucosal and invasive diseases. These organisms express surface structures called pili that adhere to host cells and promote colonization. They are defined in vitro by their ability to hemagglutinate human erythrocytes. Pili are composed predominantly of a subunit called pilin. Detailed molecular analysis of the pilus structure may provide information leading to the development of a vaccine capable of blocking microbial attachment. The gene encoding pilin (hifA) was cloned and the deduced primary structure had homology to various E. coli pilus subunits. Further genetic analysis of DNA surrounding the pilin gene revealed additional genes involved in pilus expression. One gene, hifC, was found to express a putative outer membrane protein most likely required for the assembly of pilus subunits into pili on the cell surface. Amino acid homology studies suggested that two other genes, hifD and hifE, encoded pilus structural components. Antisera were made against HifD and HifE proteins expressed from the cloned genes and these antisera were used to demonstrate that both proteins were pilus components localized at the tip of the pilus structure. The hifD and hifE genes and corresponding proteins of many H. influenzae stains were compared and these comparisons revealed that the proteins were genetically and immunologically conserved among organisms responsible for invasive diseases but variable among organisms causing surface localized diseases. These studies demonstrate that H. influenzae pili are heteropolymeric structures and provide the molecular detail necessary to define the adhesive nature of pili and to identify conserved regions of pili useful for vaccine development.Ph.D.Epidemiologic ScienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/104829/1/9610195.pdfDescription of 9610195.pdf : Restricted to UM users only

Prevalence of genetic differences in phosphorylcholine expression between nontypeable <it>Haemophilus influenzae </it>and <it>Haemophilus haemolyticus</it>

<p>Abstract</p> <p>Background</p> <p>Although non-typeable (NT) <it>Haemophilus influenzae </it>and <it>Haemophilus haemolyticus </it>are closely related human commensals, <it>H. haemolyticus </it>is non-pathogenic while NT <it>H. influenzae </it>is an important cause of respiratory tract infections. Phase-variable phosphorylcholine (ChoP) modification of lipooligosaccharide (LOS) is a NT <it>H. influenzae </it>virulence factor that, paradoxically, may also promote complement activation by binding C-reactive protein (CRP). CRP is known to bind more to ChoP positioned distally than proximally in LOS, and the position of ChoP within LOS is dictated by specific <it>licD </it>alleles (designated here as <it>licD_I</it>, <it>licD_III</it>, and <it>licD_IV</it>) that are present in a <it>lic1 </it>locus. The <it>lic1 </it>locus contains the <it>licA</it>-<it>licD </it>genes, and ChoP-host interactions may also be influenced by a second <it>lic1 </it>locus that allows for dual ChoP substitutions in the same strain, or by the number of <it>licA </it>gene tetranucleotide repeats (5'-CAAT-3') that reflect phase-variation mutation rates.</p> <p>Results</p> <p>Using dot-blot hybridization, 92% of 88 NT <it>H. influenzae </it>and 42.6% of 109 <it>H. haemolyticus </it>strains possessed a <it>lic1 </it>locus. Eight percent of NT <it>H. influenzae </it>and none of the <it>H. haemolyticus </it>strains possessed dual copies of <it>lic1</it>. The <it>licD_III</it>and <it>licD_IV</it>gene alleles were distributed similarly (18-22%) among the NT <it>H. influenzae </it>and <it>H. haemolyticus </it>strains while <it>licD_I</it>alleles were present in 45.5% of NT <it>H. influenzae </it>but in less than 1% of <it>H. haemolyticus </it>strains (<it>P </it>< .0001). NT <it>H. influenzae </it>had an average of 26.8 tetranucleotide repeats in <it>licA </it>compared to14.8 repeats in <it>H. haemolyticus </it>(<it>P </it>< .05). In addition, NT <it>H. influenzae </it>strains that possessed a <it>licD_III</it>allele had increased numbers of repeats compared to NT <it>H. influenzae </it>with other <it>licD </it>alleles (<it>P </it>< .05).</p> <p>Conclusions</p> <p>These data demonstrate that genetic similarities and differences of ChoP expression exist between NT <it>H. influenzae </it>and <it>H. haemolyticus </it>and strengthen the hypothesis that, at the population level, these differences may, in part, provide an advantage in the virulence of NT <it>H. influenzae</it>.</p

The Staphylococcus aureus Map protein is an immunomodulator that interferes with T cell–mediated responses

Staphylococcus aureus (SA) is an opportunistic pathogen that affects a variety of organ systems and is responsible for many diseases worldwide. SA express an MHC class II analog protein (Map), which may potentiate SA survival by modulating host immunity. We tested this hypothesis in mice by generating Map-deficient SA (Map(–)SA) and comparing disease outcome to wild-type Map(+)SA–infected mice. Map(–)SA–infected mice presented with significantly reduced levels of arthritis, osteomyelitis, and abscess formation compared with control animals. Furthermore, Map(–)SA–infected nude mice developed arthritis and osteomyelitis to a severity similar to Map(+)SA–infected controls, suggesting that T cells can affect disease outcome following SA infection and Map may attenuate cellular immunity against SA. The capacity of Map to alter T cell function was tested more specifically in vitro and in vivo using native and recombinant forms of Map. T cells or mice treated with recombinant Map had reduced T cell proliferative responses and a significantly reduced delayed-type hypersensitivity response to challenge antigen, respectively. These data suggest a role for Map as an immunomodulatory protein that may play a role in persistent SA infections by affecting protective cellular immunity

Prevalence of the hifBC, hmw1A, hmw2A, hmwC, and hia Genes in Haemophilus influenzae Isolates

Adherence of Haemophilus influenzae to respiratory epithelial cells is the first step in the pathogenesis of H. influenzae infection and is facilitated by the action of several adhesins located on the surface of the bacteria. In this study, prevalences of hifBC, which represent the pilus gene cluster; hmw1A, hmw2A, and hmwC, which represent high-molecular-weight (HMW) adhesin genes; and hia, which represents H. influenzae adhesin (Hia) genes were determined among clinical isolates of encapsulated type b (Hib) and nonencapsulated (NTHi) H. influenzae. hifBC genes were detected in 109 of 170 (64%) Hib strains and in 46 of 162 (28%) NTHi isolates (P = 0.0001) and were more prevalent among the invasive type b strains than invasive NTHi strains (P = 0.00003). Furthermore, hifBC genes were significantly more prevalent (P = 0.0398) among NTHi throat isolates than NTHi middle ear isolates. hmw1A, hmw2A, hmwC, and hia genes were not detected in Hib strains. Among NTHi isolates, the prevalence of hmw1A was 51%, the prevalence of hmw2A was 23%, the prevalence of hmwC was 48%, and the prevalence of hia was 33%. The hmw genes were significantly more prevalent among middle ear than throat isolates, while hia did not segregate with a respiratory tract site. These results show the variability of the presence of adhesin genes among clinical H. influenzae isolates and suggest that hemagglutinating pili may play a larger role in H. influenzae nasopharyngeal colonization than in acute otitis media whereas the HMW adhesins may be virulence factors for acute otitis media

Heterogeneity in Tandem Octanucleotides within Haemophilus influenzae Lipopolysaccharide Biosynthetic Gene losA Affects Serum Resistance

Haemophilus influenzae is subject to phase variation mediated by changes in the length of simple sequence repeat regions within several genes, most of which encode either surface proteins or enzymes involved in the synthesis of lipopolysaccharides (LPS). The translational repeat regions that have been described thus far all consist of tandemly repeated tetranucleotides. We describe an octanucleotide repeat region within a putative LPS biosynthetic gene, losA. Approximately 20 percent of nontypeable H. influenzae strains contain copies of losA and losB in a genetic locus flanked by infA and ksgA. Of 30 strains containing losA at this site, 24 contained 2 tandem copies of the octanucleotide CGAGCATA, allowing full-length translation of losA (on), and 6 strains contained 3, 4, 6, or 10 tandem copies (losA off). For a serum-sensitive strain, R3063, with losA off (10 repeat units), selection for serum-resistant variants yielded a heterogeneous population in which colonies with increased serum resistance had losA on (2, 8, or 11 repeat units), and colonies with unchanged sensitivity to serum had 10 repeats. Inactivation of losA in strains R3063 and R2846 (strain 12) by insertion of the cat gene decreased the serum resistance of these strains compared to losA-on variants and altered the electrophoretic mobility of LPS. We conclude that expression of losA, a gene that contributes to LPS structure and affects serum resistance, is determined by octanucleotide repeat variation