Nanogel-based pneumococcal surface protein A nasal vaccine induces microRNA-associated Th17 cell responses with neutralizing antibodies against Streptococcus pneumoniae in macaques.

Mucosal Immunol. 2015 Feb 11. doi: 10.1038/mi.2015.5. [Epub ahead of print]

Nanogel-based pneumococcal surface protein A nasal vaccine induces microRNA-associated Th17 cell responses with neutralizing antibodies against Streptococcus pneumoniae in macaques.

Fukuyama Y1, Yuki Y2, Katakai Y3, Harada N4, Takahashi H5, Takeda S5, Mejima M1, Joo S1, Kurokawa S1, Sawada S5, Shibata H6, Park EJ1, Fujihashi K7, Briles DE8, Yasutomi Y6, Tsukada H4, Akiyoshi K5, Kiyono H2.

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Abstract

We previously established a nanosized nasal vaccine delivery system by using a cationic cholesteryl group-bearing pullulan nanogel (cCHP nanogel), which is a universal protein-based antigen-delivery vehicle for adjuvant-free nasal vaccination. In the present study, we examined the central nervous system safety and efficacy of nasal vaccination with our developed cCHP nanogel containing pneumococcal surface protein A (PspA-nanogel) against pneumococcal infection in nonhuman primates. When [18F]-labeled PspA-nanogel was nasally administered to a rhesus macaque (Macaca mulatta), longer-term retention of PspA was noted in the nasal cavity when compared with administration of PspA alone. Of importance, no deposition of [18F]-PspA was seen in the olfactory bulbs or brain. Nasal PspA-nanogel vaccination effectively induced PspA-specific serum IgG with protective activity and mucosal secretory IgA (SIgA) Ab responses in cynomolgus macaques (Macaca fascicularis). Nasal PspA-nanogel-induced immune responses were mediated through T-helper (Th) 2 and Th17 cytokine responses concomitantly with marked increases in the levels of miR-181a and miR-326 in the serum and respiratory tract tissues, respectively, of the macaques. These results demonstrate that nasal PspA-nanogel vaccination is a safe and effective strategy for the development of a nasal vaccine for the prevention of pneumonia in humans.Mucosal Immunology advance online publication, 11 February 2015; doi:10.1038/mi.2015.5.

PMID: 25669148 [PubMed - as supplied by publisher]

Following the equator: division site selection in Streptococcus pneumoniae.

Trends Microbiol. 2015 Feb 12. pii: S0966-842X(15)00028-1. doi: 10.1016/j.tim.2015.02.001. [Epub ahead of print]

Following the equator: division site selection in Streptococcus pneumoniae.

Bramkamp M1.

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Abstract

The mechanisms that spatially regulate cytokinesis are more diverse than initially thought. In two recent publications a positive regulator of FtsZ positioning has been identified in Streptococcus pneumoniae. MapZ (LocZ) connects the division machinery with cell wall elongation, providing a simple mechanism to ensure correct division site selection.

Copyright © 2015 Elsevier Ltd. All rights reserved.

KEYWORDS:

FtsZ; MapZ; Streptococcus pneumoniae; cell division; cell wall

PMID: 25684260 [PubMed - as supplied by publisher]

Synchrony in serum antibody response to conserved proteins of Streptococcus pneumoniae in young children.

Hum Vaccin Immunother. 2015 Feb 18:0. [Epub ahead of print]

Synchrony in serum antibody response to conserved proteins of Streptococcus pneumoniae in young children.

Ren D1, Almudevar AL, Pichichero ME.

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Abstract

Background: Conserved Streptococcus pneumonia (Spn) proteins are currently under investigation as vaccine candidates. We recently identified a subset of children prone to frequent acute otitis media (AOM) that we refer to as stringently-defined otitis prone (sOP). Methods: We investigated the synchrony of serum antibody responses against 5 Spn protein vaccine antigens, PhtD, LytB, PcpA, PhtE, and PlyD1 resulting from nasopharyngeal colonization and AOM in sOP children (49 observations) and non-otitis prone (NOP) children (771 observations). Changes in serum IgG and IgM were quantitated with ELISA. Results: IgG antibody concentrations against PhtD, PcpA, and PlyD1 rose in synchrony in sOP and NOP children; that is, the proteins appeared equally and highly immunogenic in children at age 6 to 15 months and then leveled off in their rise at 15 to 25 months. In contrast, rises in concentrations to PhtE and LytB were significantly slower and had not peaked in children even at 25 months of age, consistent with lower immunogenicity. Serum IgM responses against PhtD and PlyD1 were in synchrony in children at age 6-25 months old. PcpA did not induce a significant increase of serum IgM response in children, suggesting that primary responses to PcpA occurred prior to children attaining age 6 months old. Conclusions: PhtD, PcpA, and Ply elicit a synchronous natural acquisition of serum antibody in young children suggesting that a trivalent Spn protein vaccine combining PhtD, PcpA, and PlyD1 would be less likely to display antigen competition when administered as a combination vaccine in young children.

KEYWORDS:

AOM, acute otitis media; ELISA, Enzyme-linked Immunosorbent Assay; GAM, generalized additive model; GAMM, generalized additive mixed model; LC, log10 Concentration; LME, linear mixed effects; NOP, non-otitis prone; NP, nasopharyngeal; OP, otitis prone; PCV, pneumococcal conjugate vaccine; PcpA, pneumococcal choline binding protein A; PhtD, pneumococcal histidine triad protein D; PhtE, pneumococcal histidine triad protein E; Ply, pneumolysin; PlyD1, pneumolysin derivative 1; Spn, Streptococcus pneumoniae; Streptococcus pneumoniae; generalized additive mixed model; generalized additive model; nasopharynx; pneumococcal choline binding protein A; pneumococcal conjugate vaccine; pneumococcal histidine triad protein D; pneumococcal histidine triad protein E; pneumolysin; sOP, stringently-defined otitis prone

PMID: 25692218 [PubMed - as supplied by publisher]

Transcriptional Attenuation Controls Macrolide Inducible Efflux and Resistance in Streptococcus pneumoniae and in Other Gram-Positive Bacteria Containing mef/mel(msr(D)) Elements.

PLoS One. 2015 Feb 19;10(2):e0116254. doi: 10.1371/journal.pone.0116254. eCollection 2015.

Transcriptional Attenuation Controls Macrolide Inducible Efflux and Resistance in Streptococcus pneumoniae and in Other Gram-Positive Bacteria Containing mef/mel(msr(D)) Elements.

Chancey ST1, Bai X1, Kumar N2, Drabek EF2, Daugherty SC2, Colon T2, Ott S2, Sengamalay N2, Sadzewicz L2, Tallon LJ2, Fraser CM3, Tettelin H4, Stephens DS1.

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Abstract

Macrolide resistance, emerging in Streptococcus pneumoniae and other Gram-positive bacteria, is increasingly due to efflux pumps encoded by mef/mel(msr) operons found on discrete mobile genetic elements. The regulation of mef/mel(msr) in these elements is not well understood. We identified the mef(E)/mel transcriptional start, localized the mef(E)/mel promoter, and demonstrated attenuation of transcription as a mechanism of regulation of macrolide-inducible mef-mediated macrolide resistance in S. pneumoniae. The mef(E)/mel transcriptional start site was a guanine 327 bp upstream of mef(E). Consensus pneumococcal promoter -10 (5'-TATACT-3') and -35 (5'-TTGAAC-3') boxes separated by 17 bp were identified 7 bp upstream of the start site. Analysis of the predicted secondary structure of the 327 5' region identified four pairs of inverted repeats R1-R8 predicted to fold into stem-loops, a small leader peptide [MTASMRLR, (Mef(E)L)] required for macrolide induction and a Rho-independent transcription terminator. RNA-seq analyses provided confirmation of transcriptional attenuation. In addition, expression of mef(E)L was also influenced by mef(E)L-dependent mRNA stability. The regulatory region 5' of mef(E) was highly conserved in other mef/mel(msr)-containing elements including Tn1207.1 and the 5612IQ complex in pneumococci and Tn1207.3 in Group A streptococci, indicating a regulatory mechanism common to a wide variety of Gram-positive bacteria containing mef/mel(msr) elements.

PMID: 25695510 [PubMed - in process] PMCID: PMC4335068

Effects of Immunomodulators on Functional Activity of Innate Immunity Cells Infected with Streptococcus pneumoniae.

Bull Exp Biol Med. 2015 Feb 24. [Epub ahead of print]

Effects of Immunomodulators on Functional Activity of Innate Immunity Cells Infected with Streptococcus pneumoniae.

Plekhova NG1, Kondrashova NM, Somova LM, Drobot EI, Lyapun IN.

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Abstract

Low activity of bactericidal enzymes was found in innate immunity cells infected with S. pneumonia. The death of these cells was fastened under these conditions. On the contrary, treatment with antibiotic maxifloxacin was followed by an increase in activity of bactericidal enzymes in phagocytes and induced their death via necrosis. Analysis of the therapeutic properties of immunomodulators tinrostim and licopid in combination with maxifloxacin showed that these combinations correct functional activity of cells infected with S. pneumonia.

PMID: 25708326 [PubMed - as supplied by publisher]

Composite mobile genetic elements disseminating macrolide resistance in Streptococcus pneumoniae.

Front Microbiol. 2015 Feb 9;6:26. doi: 10.3389/fmicb.2015.00026. eCollection 2015.

Composite mobile genetic elements disseminating macrolide resistance in Streptococcus pneumoniae.

Chancey ST1, Agrawal S2, Schroeder MR1, Farley MM1, Tettelin H3, Stephens DS1.

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Abstract

Macrolide resistance in Streptococcus pneumoniae emerged in the U.S. and globally during the early 1990's. The RNA methylase encoded by erm(B) and the macrolide efflux genes mef(E) and mel were identified as the resistance determining factors. These genes are disseminated in the pneumococcus on mobile, often chimeric elements consisting of multiple smaller elements. To better understand the variety of elements encoding macrolide resistance and how they have evolved in the pre- and post-conjugate vaccine eras, the genomes of 121 invasive and ten carriage isolates from Atlanta from 1994 to 2011 were analyzed for mobile elements involved in the dissemination of macrolide resistance. The isolates were selected to provide broad coverage of the genetic variability of antibiotic resistant pneumococci and included 100 invasive isolates resistant to macrolides. Tn916-like elements carrying mef(E) and mel on the Macrolide Genetic Assembly (Mega) and erm(B) on the erm(B) element and Tn917 were integrated into the pneumococcal chromosome backbone and into larger Tn5253-like composite elements. The results reported here include identification of novel insertion sites for Mega and characterization of the insertion sites of Tn916-like elements in the pneumococcal chromosome and in larger composite elements. The data indicate that integration of elements by conjugation was infrequent compared to recombination. Thus, it appears that conjugative mobile elements allow the pneumococcus to acquire DNA from distantly related bacteria, but once integrated into a pneumococcal genome, transformation and recombination is the primary mechanism for transmission of novel DNA throughout the pneumococcal population.

KEYWORDS:

Streptococcus pneumoniae; antibiotic resistance; integrative and conjugative elements; macrolides; mobile genetic elements; transposons

PMID: 25709602 [PubMed]

Pneumococcal wall teichoic acid is required for the pathogenesis of Streptococcus pneumoniae in murine models.

J Microbiol. 2015 Feb;53(2):147-54. doi: 10.1007/s12275-015-4616-4. Epub 2015 Jan 28.

Pneumococcal wall teichoic acid is required for the pathogenesis of Streptococcus pneumoniae in murine models.

Xu H1, Wang L, Huang J, Zhang Y, Ma F, Wang J, Xu W, Zhang X, Yin Y, Wu K.

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Abstract

Pneumococcal asymptomatic colonization of the respiratory tracts is a major risk for invasive pneumococcal disease. We have previously shown that pneumococcal wall teichoic acid (WTA) was involved in pneumococcal infection of sepsis and adherence to epithelial and endothelial cells. In this study, we investigated the contribution of pneumococcal WTA to bacterial colonization and dissemination in murine models. The result showed that nasopharynx colonizing D39 bacterial cells have a distinct phenotype showing an increased exposure of teichoic acids relative to medium-grown bacteria. The WTA-deficient mutants were impaired in their colonization to the nasopharynx and lungs, and led to a mild inflammation in the lungs at 36 h post-inoculation. Pretreatment of the murine nares with WTA reduced the ability of wild type D39 bacteria to colonize the nasopharynx. In addition, the WTA-deficient strain was impaired in its ability to invade the blood and brain following intranasal administration. WTA-deficient D39 strain was reduced in C3 deposition but was more susceptible to the killing by the neutrophils as compared with its parent strain. Our results also demonstrated that the WTA enhanced pneumococcal colonization and dissemination independently of the host strains. These results indicate that WTA plays an important role in pneumococcal pathogenesis, both in colonization and dissemination processes.

PMID: 25626371 [PubMed - in process]

Streptococcus pneumoniae biofilm formation and dispersion during colonization and disease.

Front Cell Infect Microbiol. 2015 Jan 13;4:194. doi: 10.3389/fcimb.2014.00194. eCollection 2014.

Streptococcus pneumoniae biofilm formation and dispersion during colonization and disease.

Chao Y1, Marks LR2, Pettigrew MM3, Hakansson AP4.

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Abstract

Streptococcus pneumoniae (the pneumococcus) is a common colonizer of the human nasopharynx. Despite a low rate of invasive disease, the high prevalence of colonization results in millions of infections and over one million deaths per year, mostly in individuals under the age of 5 and the elderly. Colonizing pneumococci form well-organized biofilm communities in the nasopharyngeal environment, but the specific role of biofilms and their interaction with the host during colonization and disease is not yet clear. Pneumococci in biofilms are highly resistant to antimicrobial agents and this phenotype can be recapitulated when pneumococci are grown on respiratory epithelial cells under conditions found in the nasopharyngeal environment. Pneumococcal biofilms display lower levels of virulence in vivo and provide an optimal environment for increased genetic exchange both in vitro and in vivo, with increased natural transformation seen during co-colonization with multiple strains. Biofilms have also been detected on mucosal surfaces during pneumonia and middle ear infection, although the role of these biofilms in the disease process is debated. Recent studies have shown that changes in the nasopharyngeal environment caused by concomitant virus infection, changes in the microflora, inflammation, or other host assaults trigger active release of pneumococci from biofilms. These dispersed bacteria have distinct phenotypic properties and transcriptional profiles different from both biofilm and broth-grown, planktonic bacteria, resulting in a significantly increased virulence in vivo. In this review we discuss the properties of pneumococcal biofilms, the role of biofilm formation during pneumococcal colonization, including their propensity for increased ability to exchange genetic material, as well as mechanisms involved in transition from asymptomatic biofilm colonization to dissemination and disease of otherwise sterile sites. Greater understanding of pneumococcal biofilm formation and dispersion will elucidate novel avenues to interfere with the spread of antibiotic resistance and vaccine escape, as well as novel strategies to target the mechanisms involved in induction of pneumococcal disease.

KEYWORDS:

biofilm; colonization; streptococcus; virulence; virus

PMID: 25629011 [PubMed - in process] PMCID: PMC4292784

Uptake of extracellular DNA: Competence induced pili in natural transformation of Streptococcus pneumoniae.

Bioessays. 2015 Jan 15. doi: 10.1002/bies.201400125. [Epub ahead of print]

Uptake of extracellular DNA: Competence induced pili in natural transformation of Streptococcus pneumoniae.

Muschiol S1, Balaban M, Normark S, Henriques-Normark B.

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Abstract

Transport of DNA across bacterial membranes involves complex DNA uptake systems. In Gram-positive bacteria, the DNA uptake machinery shares fundamental similarities with type IV pili and type II secretion systems. Although dedicated pilus structures, such as type IV pili in Gram-negative bacteria, are necessary for efficient DNA uptake, the role of similar structures in Gram-positive bacteria is just beginning to emerge. Recently two essentially very different pilus structures composed of the same major pilin protein ComGC were proposed to be involved in transformation of the Gram-positive bacterium Streptococcus pneumoniae - one is a long, thin, type IV pilus-like fiber with DNA binding capacity and the other one is a pilus structure that was thicker, much shorter and not able to bind DNA. Here we discuss how competence induced pili, either by pilus retraction or by a transient pilus-related opening in the cell wall, may mediate DNA uptake in S. pneumoniae.

© 2015 The Authors. Bioessays published by WILEY Periodicals, Inc.

KEYWORDS:

Streptococcus pneumoniae; competence pilus; pneumococci; transformation

PMID: 25640084 [PubMed - as supplied by publisher]

Multicenter Surveillance of Streptococcus pneumoniae Isolates from Middle Ear and Mastoid Cultures in the 13-Valent Pneumococcal Conjugate Vaccine Era.

Clin Infect Dis. 2015 Feb 3. pii: civ067. [Epub ahead of print]

Multicenter Surveillance of Streptococcus pneumoniae Isolates from Middle Ear and Mastoid Cultures in the 13-Valent Pneumococcal Conjugate Vaccine Era.

Kaplan SL1, Center KJ2, Barson WJ3, Ling-Lin P4, Romero JR5, Bradley JS6, Tan TQ7, Hoffman JA8, Peters TR9, Gurtman A2, Scott DA2, Trammel J2, Gruber WC2, Hulten KG1, Mason EO1.

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Abstract

BACKGROUND:

 Streptococcus pneumoniae is a common cause of otitis media (OM) in children; mastoiditis remains an important complication of OM. Limited data are available on the impact of the 13-valent pneumococcal conjugate vaccine (PCV13) on pneumococcal otitis.

METHODS:

 Investigators from 8 children's hospitals in the United States prospectively collected pneumococcal isolates from middle ear or mastoid cultures from children during 2011 to 2013. Serotype and antibiotic susceptibilities were determined and PCV13 doses for children documented.

RESULTS:

 Over the three years the proportion of isolates included in PCV13 (plus a related serotype) decreased significantly (p=0.0006) among the middle ear/mastoid isolates [2011, 50% (74/149); 2012, 40.5% (47/116); 2013, 29% (34/118)]. The number of serotype 19A isolates in 2013 (n=12, 10.2% of total)) decreased 76% compared to the number of 19A isolates in 2011 (n=50, 33.6% of total). Of the children from whom serotype 19A was isolated (n=93), 55% had previously received<3 doses of PCV13. The most common non-PCV13 serotypes for the combined years were 35B (n=37), 21 (n=20), 23B (n=20), 15B (n=18), 11 (n=17), 23A (n=14), 15A (n=14), and 15C (n=14). The proportion of isolates with penicillin MIC >2 µg/mL decreased significantly over the three years. (2011, 22% [35/154]; 2012, 20% [24/118]; 2013, 10% [12/120]; p< 0.02).

CONCLUSIONS:

 The number of pneumococcal isolates and the percentage of isolates with high-level penicillin resistance from cultures taken from children with OM or mastoiditis for clinical indications have decreased following PCV13 use, largely related to decreases in serotype 19A isolates.

© The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

PMID: 25648240 [PubMed - as supplied by publisher]

Phenotypic and Functional Analysis of HL-60 Cells Used in Opsonophagocytic-Killing Assay for Streptococcus pneumoniae.

J Korean Med Sci. 2015 Feb;30(2):145-50. doi: 10.3346/jkms.2015.30.2.145. Epub 2015 Jan 21.

Phenotypic and Functional Analysis of HL-60 Cells Used in Opsonophagocytic-Killing Assay for Streptococcus pneumoniae.

Kim KH1, Seoh JY2, Cho SJ1.

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Abstract

Differentiated HL-60 is an effector cell widely used for the opsonophagocytic-killing assay (OPKA) to measure efficacy of pneumococcal vaccines. We investigated the correlation between phenotypic expression of immunoreceptors and phagocytic ability of HL-60 cells differentiated with N,N-dimethylformamide (DMF), all-trans retinoic acid (ATRA), or 1α, 25-dihydroxyvitamin D3 (VitD3) for 5 days. Phenotypic change was examined by flow cytometry with specific antibodies to CD11c, CD14, CD18, CD32, and CD64. Apoptosis was determined by flow cytometry using 7-aminoactinomycin D. Function was evaluated by a standard OPKA against serotype 19F and chemiluminescence-based respiratory burst assay. The expression of CD11c and CD14 gradually increased upon exposure to all three agents, while CD14 expression increased abruptly after VitD3. The expression of CD18, CD32, and CD64 increased during differentiation with all three agents. Apoptosis remained less than 10% until day 3 but increased after differentiation by DMF or ATRA. Differentiation with ATRA or VitD3 increased the respiratory burst after day 4. DMF differentiation showed a high OPKA titer at day 1 which sustained thereafter while ATRA or VitD3-differentiated cells gradually increased. Pearson analysis between the phenotypic changes and OPKA titers suggests that CD11c might be a useful differentiation marker for HL-60 cells for use in pneumococcal OPKA.

KEYWORDS:

Differentiation; HL-60; Opsonophagocytic-Killing Assay; Streptococcus pneumonia

PMID: 25653484 [PubMed - in process] PMCID: PMC4310939 

The C-Type Lectin Receptor Mincle Binds to Streptococcus pneumoniae but Plays a Limited Role in the Anti-Pneumococcal Innate Immune Response.

PLoS One. 2015 Feb 6;10(2):e0117022. doi: 10.1371/journal.pone.0117022. eCollection 2015.

The C-Type Lectin Receptor Mincle Binds to Streptococcus pneumoniae but Plays a Limited Role in the Anti-Pneumococcal Innate Immune Response.

Rabes A1, Zimmermann S2, Reppe K1, Lang R3, Seeberger PH4, Suttorp N1, Witzenrath M1, Lepenies B2, Opitz B1.

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Abstract

The innate immune system employs C-type lectin receptors (CLRs) to recognize carbohydrate structures on pathogens and self-antigens. The Macrophage-inducible C-type lectin (Mincle) is a FcRγ-coupled CLR that was shown to bind to mycobacterial cord factor as well as certain fungal species. However, since CLR functions during bacterial infections have not yet been investigated thoroughly, we aimed to examine their function in Streptococcus pneumonia infection. Binding studies using a library of recombinantly expressed CLR-Fc fusion proteins indicated a specific, Ca2+-dependent, and serotype-specific binding of Mincle to S. pneumonia. Subsequent experiments with different Mincle-expressing cells as well as Mincle-deficient mice, however, revealed a limited role of this receptor in bacterial phagocytosis, neutrophil-mediated killing, cytokine production, and antibacterial immune response during pneumonia. Collectively, our results indicate that Mincle is able to recognize S. pneumonia but is not required for the anti-pneumococcal innate immune response.

PMID: 25658823 [PubMed - in process]