bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neutralization of Macrophage Inflammatory Protein 2 (MIP-2) and MIP-1α Attenuates Neutrophil Recruitment in the Central Nervous System during Experimental Bacterial Meningitis
Authors: Diab Asim , Abdalla Hana , Li Hu Lun , Shi Fu Dong , Zhu Jie , Höjberg Bo , Lindquist Lars , Wretlind Bengt , Bakhiet Moiz , Link Hans 
Published: December 2019

ABSTRACTChemokines are low-molecular-weight chemotactic cytokines that have been shown to play a central role in the perivascular transmigration and accumulation of specific subsets of leukocytes at sites of tissue damage. Using in situ hybridization (ISH), we investigated the mRNA induction of macrophage inflammatory protein 2 (MIP-2), MIP-1α, monocyte chemoattractant protein 1 (MCP-1), and RANTES. Challenge of infant rats’ brains withHaemophilus influenzaetype b intraperitoneally resulted in the time-dependent expression of MIP-2, MIP-1α, MCP-1, and RANTES, which was maximal 24 to 48 h postinoculation. Immunohistochemistry showed significant increases in neutrophils and macrophages infiltrating the meninges, the ventricular system, and the periventricular area. The kinetics of MIP-2, MIP-1α, MCP-1, and RANTES mRNA expression paralleled those of the recruitment of inflammatory cells and disease severity. Administration of anti-MIP-2 or anti-MIP-1α antibodies (Abs) resulted in significant reduction of neutrophils. Administration of anti-MCP-1 Abs significantly decreased macrophage infiltration. Combined studies of ISH and immunohistochemistry showed that MIP-2- and MIP-1α-positive cells were neutrophils and macrophages. MCP-1-positive cells were neutrophils, macrophages, and astrocytes. Expression of RANTES was localized predominantly to resident astrocytes and microglia. The present study indicates that blocking of MIP-2 or MIP-1α bioactivity in vivo results in decreased neutrophil influx. These data are also the first demonstration that the C-C chemokine MIP-1α is involved in neutrophil recruitment in vivo.
Antibody to Glucosyltransferase Induced by Synthetic Peptides Associated with Catalytic Regions of α-Amylases
Authors: Smith Daniel J. , Heschel Rhonda L. , King William F. , Taubman Martin A. 
Published: December 2019

ABSTRACT

We examined the immunogenicity and induction of inhibitory activity of 19-mer synthetic peptides which contained putative catalytic regions that were associated with the β
5
(EAW) and β
7
(HDS) strand elements of the suggested (β,α)
8
catalytic barrel domain of
Streptococcus mutans
glucosyltransferase (GTF). Both peptides readily induced serum immunoglobulin G (IgG) and salivary IgA antipeptide activity which was reactive both with the inciting peptide and with intact
S. mutans
GTF. Antisera to each peptide construct also inhibited the ability of
S. mutans
GTF to synthesize glucan. These observations support the existence of catalytic subdomains containing glutamate and tryptophan (EAW) or aspartate and histidine (HDS) residues, each of which have been suggested to be involved with the catalytic activity of GTF. Furthermore, the epitopes defined in these sequences have significant immunogenicity and can induce immune responses which interfere with GTF-mediated glucan synthesis.
Binding of
Haemophilus ducreyi
to Extracellular Matrix Proteins
Authors: Bauer Margaret E. , Spinola Stanley M. 
Published: December 2019

ABSTRACT

We developed an enzyme-linked immunosorbent assay-based assay to assess
Haemophilus ducreyi
binding to extracellular matrix (ECM) proteins.
H. ducreyi
35000HP bound to fibronectin, laminin, and type I and III collagen but not to type IV, V, or VI collagen or elastin. Isogenic strains with mutations in
ftpA
or
losB
bound as well as the parent, suggesting that neither pili nor full-length lipooligosaccharide is required for
H. ducreyi
to bind to ECM proteins.
T-Cell Epitope Mapping of the Three Most Abundant Extracellular Proteins ofMycobacterium tuberculosisin Outbred Guinea Pigs
Authors: Lee Bai-Yu , Horwitz Marcus A. 
Published: December 2019

ABSTRACTThe three most abundant extracellular proteins ofMycobacterium tuberculosis, the 30-, 32-, and 16-kDa major extracellular proteins, are particularly promising vaccine candidates. We have mapped T-cell epitopes of these three proteins in outbred guinea pigs by immunizing the animals with each protein and assaying splenic lymphocyte proliferation against a series of overlapping synthetic peptides covering the entire length of the mature proteins. The 30-kDa protein contained nine immunodominant epitopes, the 32-kDa protein contained two immunodominant epitopes, and the 16-kDa protein contained a highly immunodominant region at its N terminus. The immunodominant epitopes of the 30- and 32-kDa proteins in outbred guinea pigs were frequently identified in healthy purified-protein-derivative-positive or BCG-vaccinated individuals in previous studies. The immunodominant epitopes of these major extracellular proteins have potential utility in an epitope-based vaccine against tuberculosis.
Production of β-Defensin Antimicrobial Peptides by the Oral Mucosa and Salivary Glands
Authors: Mathews Michael , Jia Hong Peng , Guthmiller Janet M. , Losh Garrett , Graham Scott , Johnson Georgia K. , Tack Brian F. , McCray Paul B. 
Published: December 2019

ABSTRACT
β-Defensins are cationic peptides with broad-spectrum antimicrobial activity that are produced by epithelia at mucosal surfaces. Two human β-defensins, HBD-1 and HBD-2, were discovered in 1995 and 1997, respectively. However, little is known about the expression of HBD-1 or HBD-2 in tissues of the oral cavity and whether these proteins are secreted. In this study, we characterized the expression of HBD-1 and HBD-2 mRNAs within the major salivary glands, tongue, gingiva, and buccal mucosa and detected β-defensin peptides in salivary secretions. Defensin mRNA expression was quantitated by RNase protection assays. HBD-1 mRNA expression was detected in the gingiva, parotid gland, buccal mucosa, and tongue. Expression of HBD-2 mRNA was detected only in the gingival mucosa and was most abundant in tissues with associated inflammation. To test whether β-defensin expression was inducible, gingival keratinocyte cell cultures were treated with interleukin-1β (IL-1β) or bacterial lipopolysaccharide (LPS) for 24 h. HBD-2 expression increased ∼16-fold with IL-1β treatment and ∼5-fold in the presence of LPS. Western immunoblotting, liquid chromatography, and mass spectrometry were used to identify the HBD-1 and HBD-2 peptides in human saliva. Human β-defensins are expressed in oral tissues, and the proteins are secreted in saliva; HBD-1 expression was constitutive, while HBD-2 expression was induced by IL-1β and LPS. Human β-defensins may play an important role in the innate defenses against oral microorganisms.
Protection against Development of Otitis Media Induced by NontypeableHaemophilus influenzaeby Both Active and Passive Immunization in a Chinchilla Model of Virus-Bacterium Superinfection
Authors: Bakaletz Lauren O. , Kennedy Bobbie-Jo , Novotny Laura A. , Duquesne Guy , Cohen Joe , Lobet Yves 
Published: December 2019

ABSTRACTThree separate studies, two involving active-immunization regimens and one involving a passive-transfer protocol, were conducted to initially screen and ultimately more fully assess several nontypeableHaemophilus influenzaeouter membrane proteins or their derivatives for their relative protective efficacy in chinchilla models of otitis media. Initial screening of these antigens (P5-fimbrin, lipoprotein D, and P6), delivered singly or in combination with either Freund’s adjuvant or alum, indicated that augmented bacterial clearance from the nasopharynx, the middle ears, or both anatomical sites could be induced by parenteral immunization with P5-fimbrin combined with lipoprotein D, lipoprotein D alone, or the synthetic chimeric peptide LB1 (derived from P5-fimbrin), respectively. Data from a second study, wherein chinchillas were immunized with LB1 or lipoprotein D, each delivered with alum, again indicated that clearance of nontypeableH. influenzaecould be augmented by immunization with either of these immunogens; however, when this adjuvant was used, both antibody titers in serum and efficacy were reduced. A third study was performed to investigate passive delivery of antisera directed against either LB1, lipoprotein D, nonacylated lipoprotein D, or a unique recombinant peptide designated LPD-LB1(f)2,1,3. The last three antiserum pools were generated by using the combined adjuvant of alum plus monophosphoryl lipid A. Passive transfer of sera specific for LB1 or LPD-LB1(f)2,1,3to adenovirus-compromised chinchillas, prior to intranasal challenge with nontypeableH. influenzae, significantly reduced the severity of signs and incidence of otitis media which developed (P≤ 0.001). Collectively, these data indicate the continued merit of further developing LB1 and LPD-LB1(f)2,1,3as components of vaccines for otitis media.
Cross-Reactivity between the Rheumatoid Arthritis-Associated Motif EQKRAA and Structurally Related Sequences Found in
Proteus mirabilis
Authors: Tiwana Harmale , Wilson Clyde , Alvarez Alison , Abuknesha Ramadan , Bansal Sukhvinder , Ebringer Alan 
Published: December 2019

ABSTRACT

Cross-reactivity or molecular mimicry may be one of the underlying mechanisms involved in the etiopathogenesis of rheumatoid arthritis (RA). Antiserum against the RA susceptibility sequence EQKRAA was shown to bind to a similar peptide ESRRAL present in the hemolysin of the gram-negative bacterium
Proteus mirabilis
, and an anti-ESRRAL serum reacted with EQKRAA. There was no reactivity with either anti-EQKRAA or anti-ESRRAL to a peptide containing the EDERAA sequence which is present in HLA-DRB1∗0402, an allele not associated with RA. Furthermore, the EQKRAA and ESRRAL antisera bound to a mouse fibroblast transfectant cell line (Dap.3) expressing HLA-DRB1∗0401 but not to DRB1∗0402. However, peptide sequences structurally related to the RA susceptibility motif LEIEKDFTTYGEE (
P. mirabilis
urease), VEIRAEGNRFTY (collagen type II) and DELSPETSPYVKE (collagen type XI) did not bind significantly to cell lines expressing HLA-DRB1∗0401 or HLA-DRB1∗0402 compared to the control peptide YASGASGASGAS. It is suggested here that molecular mimicry between HLA alleles associated with RA and
P. mirabilis
may be relevant in the etiopathogenesis of the disease.
Access of Antibody or Trypsin to an Integral Outer Membrane Protein (P66) ofBorrelia burgdorferiIs Hindered by Osp Lipoproteins
Authors: Bunikis Jonas , Barbour Alan G. 
Published: December 2019

ABSTRACTThe outer membrane ofBorrelia burgdorferi, the Lyme disease agent, contains lipoproteins anchored by their lipid moieties and integral proteins with membrane-spanning regions. We used the techniques of in situ proteolysis, immunofluorescence, in vitro growth inhibition, and cross-linking with formaldehyde to characterize topological relationships between P66, an integral membrane protein, and selected Osp lipoproteins ofB. burgdorferi. Protease treatment of intact spirochetes cleaved P66 and Osp proteins but not the periplasmic flagellin or the BmpA protein of the cytoplasmic membrane. P66 of cells lacking OspA, OspB, and OspC was more susceptible to trypsin cleavage than was P66 of cells with these Osp proteins. A monoclonal antibody against the surface loop of P66 bound, agglutinated, and inhibited the growth of viable spirochetes lacking OspA, OspB, OspC, and OspD but not of the cells that expressed OspA, OspC, and/or OspD. When cells were fixed, the antibody bound to cells that express OspD and OspC but still not to cells with OspA. The close association of OspA and P66 was confirmed by the crosslinking of the two proteins by formaldehyde. These results show that Osp proteins, particularly OspA, limit the access of antibody or trypsin to the surface loop region of P66. The proximity and possible contact between P66 and OspA (or other Osp proteins) may hinder the effectiveness of antibodies to what otherwise would be an appropriate vaccine target.
Genes Influencing Resistance toCoccidioides immitisand the Interleukin-10 Response Map to Chromosomes 4 and 6 in Mice
Authors: Fierer Joshua , Walls Lorraine , Wright Fred , Kirkland Theo N. 
Published: December 2019

ABSTRACTCoccidioidomycosis is a fungal infection that is endemic in the southwestern United States. Infection is more severe in blacks and Filipinos, which suggests that there is a genetic basis for susceptibility to this infection in humans. We found that there is also a difference in resistance toCoccidioides immitisinfection among inbred mouse strains: B6 mice are susceptible, while DBA/2 mice are resistant (T. N. Kirkland and J. Fierer, Infect. Immun. 40:912–916, 1983). In this paper we report the results of our efforts to map the genes responsible for resistance to this infection in mice. Mice were infected by intraperitoneal inoculation, and 15 days later the numbers of viable fungi in their lungs and spleens were enumerated. We also determined the amounts of interleukin-10 mRNA made in the infected lungs. These three phenotypes were mapped as quantitative traits by using the 26 available lines of recombinant inbred mice derived from a cross between B6 and DBA/2 mice. The best associations were those between the regions near theLvlocus on chromosome 4 and theTnfr1locus on chromosome 6. We then infected backcross mice [(B6 × DBA/2) × B6] and confirmed these associations; 14 of 16 (87%) mice that were heterozygous at bothLvandTnfr1were resistant to infection, whereas only 4 of 16 (25%) mice that were homozygous B6 at both loci were resistant. These are the first genetic loci to be associated with susceptibility toC. immitis, but there may be additional genes involved in murine resistance to this infection.
Disruption of Anthrax Toxin Binding with the Use of Human Antibodies and Competitive Inhibitors
Authors: Cirino Nick M. , Sblattero Daniele , Allen David , Peterson Scott R. , Marks James D. , Jackson Paul J. , Bradbury Andrew , Lehnert Bruce E. 
Published: December 2019

ABSTRACT

The protective antigen (PA83) of
Bacillus anthracis
is integral to the mechanism of anthrax toxicity. We have isolated a human single-chain Fv antibody fragment (scFv) that blocks binding of a fluorescently tagged protective antigen (PA) moiety to cell surface receptors. Several phage-displayed scFv were isolated from a naive library biopanned against PA83. Soluble, monomeric scFv were characterized for affinity and screened for their capacity to disrupt receptor-mediated binding of PA. Four unique scFv bound to PA83, as determined by surface plasmon resonance, the tightest binder exhibiting a

K
d

of 50 nM. Two scFv had similar affinities for natural PA83 and a novel, recombinant, 32-kDa carboxy-terminal PA fragment (PA32). Binding of scFv to green fluorescent protein fused to the amino-terminal 32-kDa fragment of
B. anthracis
edema factor, EGFP-EF32, was used to confirm specificity. Fusion of EGFP to PA32 facilitated development of a novel flow cytometric assay that showed that one of the scFv disrupted PA receptor binding. This method can now be used as a rapid assay for small molecule inhibitors of PA binding to cell receptors. The combined data presented suggest the potential utility of human scFv as prophylactics against anthrax poisoning. Moreover, recombinant PA32 may also be useful as a therapeutic agent to compete with anthrax toxins for cellular receptors during active infection.
Modulation of Major Histocompatibility Complex Protein Expression by Human Gamma Interferon Mediated by Cysteine Proteinase-Adhesin Polyproteins ofPorphyromonas gingivalis
Authors: Yun Peter L. W. , DeCarlo Arthur A. , Hunter Neil 
Published: December 2019

ABSTRACTCysteine proteinases have been emphasized in the virulence ofPorphyromonas gingivalisin chronic periodontitis. These hydrolases may promote the degradation of extracellular matrix proteins and disrupt components of the immune system. In this study it was shown that purified Arg-gingipain and Lys-gingipain inhibited expression of class II major histocompatibility complex (MHC) proteins in response to the stimulation of endothelial cells with human gamma interferon (IFN-γ). Treatment with the cysteine proteinases resulted in a rapid shift in the apparent molecular size of IFN-γ from 17 to 15 kDa, as shown by Western blot analysis, a response which also occurred in the presence of serum. Further, glycosylated natural IFN-γ from human leukocytes and unglycosylated recombinant IFN-γ fromEscherichia coliwere both digested by the cysteine proteinases. Immunoblot analysis indicated that cleavage within the carboxyl terminus of recombinant IFN-γ correlated with the loss of induction of MHC class II expression as monitored by analytical flow cytometry. No hydrolysis of MHC class II molecules or human IFN-γ receptor by these proteinases was detected by Western blot analysis. These findings suggest thatP. gingivaliscysteine proteinases may alter the cytokine network at the point of infection through the cleavage of IFN-γ. Degradation of IFN-γ could have important consequences for the recruitment and activation of leukocytes and therefore may contribute significantly to the destruction of the periodontal attachment.
Citrobacter rodentiumInfection in Mice Elicits a Mucosal Th1 Cytokine Response and Lesions Similar to Those in Murine Inflammatory Bowel Disease
Authors: Higgins Lisa M. , Frankel Gad , Douce Gill , Dougan Gordon , MacDonald Thomas T. 
Published: December 2019

ABSTRACTCitrobacter rodentiumis a classically noninvasive pathogen of mice that is similar to enteropathogenicEscherichia coli(EPEC) in man. Following oral infection of young mice, the organism colonizes the distal colon, and within 1 week the colonic mucosa doubles in thickness and there is massive epithelial cell hyperplasia. Since T-cell responses in mouse models of inflammatory bowel disease (IBD) also cause epithelial hyperplasia, we have investigated the possibility thatC. rodentiumpromotes similar T-cell responses in the mucosa, thereby increasing epithelial shedding, transmission, and replication of the organism. Beginning 6 days after infection, bacteria were observed to be in close association with the epithelial surface and were also visible scattered throughout the lamina propria and in the submucosa. There was a CD3+-cell infiltrate into the colonic lamina propria and epithelium as well as mucosal thickening and crypt hyperplasia. The majority of CD3+cells were CD4+and were not γδ+. Reverse transcription-PCR analysis of cytokines also revealed a highly polarized Th1 response (interleukin-12, gamma interferon, and tumor necrosis factor alpha) in the mucosa and a large increase in the epithelial cell mitogen keratinocyte growth factor. None of the changes were seen in mice inoculated with bacteria lacking intimin (which is necessary for colonization), but they were seen in mice inoculated withC. rodentiumcomplemented with intimin from EPEC. This is the first example of a classically noninvasive bacterial pathogen which elicits a strong mucosal Th1 response and which produces pathology similar to that seen in mouse models of IBD, which is also characterized by a strong Th1 response. These results also suggest that the colonic mucosa responds in a stereotypic way to Th1 responses.
Coinfection with Influenza B Virus Does Not Affect Association ofNeisseria meningitidiswith Human Nasopharyngeal Mucosa in Organ Culture
Authors: Read Robert C. , Goodwin Linda , Parsons M. Andrew , Silcocks Paul , Kaczmarski Edward B. , Parker Andrew , Baldwin Thomas J. 
Published: December 2019

ABSTRACTThere is an epidemiological association between influenza virus infection and meningococcal disease. Proposed mechanisms are the destruction of the normal epithelial barrier function of the upper respiratory tract by influenza virus or the expression of human or viral surface-exposed proteins that enhance bacterial adherence and/or invasion. To test these hypotheses, human nasopharyngeal mucosa specimens from a total of 19 individual donors were successfully infected with influenza B virus and then inoculated with serogroup BNeisseria meningitidis. Subsequent bacterial association with the epithelial surface was measured in three separate series of experiments by using transmission electron microscopy (n= 6), scanning electron microscopy (n= 6), and counting of viable bacteria within homogenates of explants (n= 7). Penetration of the mucosa was estimated by measuring the count of viable bacteria recovered from explants after exposure to sodium taurocholate. Bacterial association with the surface of explants was time dependent over 24 h of superinfection. Influenza virus did not positively or negatively influence bacterial attachment to or penetration of explant mucosa compared to those of uninfected controls, even when the period of preincubation with virus was extended to 7 days. When proteins were purified from mucosal epithelium and immobilized on nitrocellulose membranes,N. meningitidisattached predominantly to bands corresponding to proteins of 210 and 130 kDa. In the presence of influenza virus infection, these proteins were gradually lost over the course of 72 h. In conclusion, influenza B virus did not increase association of serogroup BN. meningitidiswith human nasopharyngeal mucosa.
Increased Antimycobacterial Immunity in Interleukin-10-Deficient Mice
Authors: Murray Peter J. , Young Richard A. 
Published: December 2019

ABSTRACTMacrophage effector functions are essential for clearing mycobacterial infections. Interleukin 10 (IL-10) negatively regulates macrophages and could be a factor inhibiting effective antimycobacterial immunity. We previously showed that transgenic mice which produce excess IL-10 from T cells are susceptible to infection, even though these mice continue to produce gamma interferon (IFN-γ) at levels similar to those in controls. Here, we extend our genetic analysis of the functions of IL-10 in antimycobacterial immunity by testing the hypothesis that IL-10-deficient (IL-10−/−) mice should be more resistant to mycobacteria than control mice.Mycobacterium bovisbacillus Calmette-Guérin-infected IL-10−/−mice had significantly lower bacterial burdens than control mice early in the infection. Contrary to expectations, however, IL-10−/−mice did not have increased levels of IFN-γ, either from T cells or in the plasma, suggesting that other mechanisms are responsible for the increased resistance. However, macrophages from IL-10−/−mice produced increased levels of inflammatory cytokines, including IFN-γ, as well as nitric oxide and prostaglandins, which could account for increased antimycobacterial immunity. Our genetic analysis revealed that IL-10 is an inhibitor of early mycobacterial clearance. The data also suggest that IL-10 negatively regulates numerous macrophage functions as well as playing a role in down-regulating the general inflammatory response, especially in conditions where an infection must be controlled through macrophage activity.