bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytokine Production Assays Reveal Discriminatory Immune Defects in Adults with Recurrent Infections and Noninfectious Inflammation
Authors: ten Oever Jaap , van de Veerdonk Frank L. , Joosten Leo A. B. , Simon Anna , van Crevel Reinout , Kullberg Bart-Jan , Gyssens Inge C. , van der Meer Jos W. M. , van Deuren Marcel , Netea Mihai G. 
Published: May 2014

ABSTRACTCytokine production assays have been primarily used in research settings studying novel immunodeficiencies. We sought to determine the diagnostic value of cytokine production assays in patients with recurrent and/or severe infectious diseases (IDs) without known immunodeficiencies and unclassified noninfectious inflammatory disorders (NIIDs). We retrospectively examined cytokine production in whole-blood and peripheral blood mononuclear cell samples from 157 adult patients. A cytokine production rate of <5% of that of healthy controls was considered defective. While monocyte-derived cytokine (tumor necrosis factor alpha [TNF-α], interleukin-1β [IL-1β], and IL-6) production was rarely affected, 30% of all included patients had deficient production of interferon gamma (IFN-γ), IL-17A, or IL-22. Twenty-five percent of the NIID patients displayed defective IFN-γ production, whereas IL-17A production was generally unaffected. In the group of ID patients, defective IFN-γ production was found in 19% and 14% of the patients with viral and bacterial infections, respectively, and in 38%, 24%, and 50% of patients with mycobacterial, mucocutaneous, and invasive fungal infections, respectively. Defective IL-17A and IL-22 production was mainly confined to ID patients with mucocutaneous fungal infections. In conclusion, cytokine production assays frequently detect defective Th1 responses in patients with mycobacterial or fungal infections, in contrast to patients with respiratory tract infections or isolated bacterial infections. Defective IL-17A and IL-22 production was primarily found in patients with fungal infections, while monocyte-derived cytokine production was unaffected. Thus, lymphocyte-derived cytokine production assays are helpful in the diagnostic workup of patients with recurrent infections and suspected immunodeficiencies and have the potential to reveal immune defects that might guide adjunctive immunomodulatory therapy.
Adaptation and Attenuation of Duck Tembusu Virus Strain Du/CH/LSD/110128 following Serial Passage in Chicken Embryos
Authors: Sun Ling , Li Yunxia , Zhang Yue , Han Zongxi , Xu Yang , Kong Xiangang , Liu Shengwang 
Published: May 2014

ABSTRACTDuck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that has caused massive economic losses to the duck industry in China. In the current study, a virulent strain of DTMUV, designated Du/CH/LSD/110128, was isolated from the livers of diseased ducks and attenuated by serial passage in embryonated chicken eggs. The virus was partially attenuated after 50 and 70 passages and was fully attenuated after 90 passages, based on mortality and morbidity rates and viral loads in inoculated ducklings. Fourteen amino acid substitutions were observed in the capsid, prM, envelope, NS1, NS3, NS4A, NS4B, and NS5 proteins of the fully attenuated strain of Du/CH/LSD/110128, which might be responsible for the observed changes in replication and pathogenicity. A 72-nucleotide deletion was also observed in the 3′ untranslated region of the virus after 30 passages. The fully attenuated virus retained the immunogenicity of the parental strain, providing effective protection to challenge with virulent Du/CH/LSD/110128, and may represent a suitable candidate as a vaccine strain against DTMUV infection in ducks. Our results also lay the foundation for future studies on the replication and pathogenic mechanisms of DTMUV.
Chemically Modified Peptides Based on the Membrane-Proximal External Region of the HIV-1 Envelope Induce High-Titer, Epitope-Specific Nonneutralizing Antibodies in Rabbits
Authors: Venditto Vincent J. , Wieczorek Lindsay , Molnar Sebastian , Teque Fernando , Landucci Gary , Watson Douglas S. , Forthal Donald , Polonis Victoria R. , Levy Jay A. , Szoka Francis C. 
Published: May 2014

ABSTRACTBroadly neutralizing monoclonal antibodies (bNAbs) 2F5 and 4E10 bind to the membrane proximal external region (MPER) of gp41 and also cross-react with phospholipids. In this study, we investigated if chemical modifications on the MPER adjacent to 2F5 and 4E10 epitopes using mimetics of inflammation-associated posttranslational modifications to induce 2F5- and 4E10-like bNAbs can break tolerance. We synthesized a series of chemically modified peptides spanning the MPER. The serine, threonine, and tyrosine residues in the peptides were modified with sulfate, phosphate, or nitrate moieties and presented in liposomes for rabbit immunizations. All immunizations resulted in high antisera titers directed toward both the modified and unmodified immunogens. Tyrosine modification was observed to significantly suppress antiepitope responses. Sera with strong anti-gp140 titers were purified by affinity chromatography toward the MPER peptide and found to possess a higher affinity toward the MPER than did the bNAbs 2F5 and 4E10. Modest neutralization was observed in the H9 neutralization assay, but neutralization was not observed in the TZM-bl cell or peripheral blood mononuclear cell (PBMC) neutralization assay platforms. Although neutralizing antibodies were not induced by this approach, we conclude that chemical modifications can increase the immune responses to poorly immunogenic antigens, suggesting that chemical modification in an appropriate immunization protocol should be explored further as an HIV-1 vaccine strategy.
Detection of Significant Bacteriuria by Use of the iQ200 Automated Urine Microscope
Authors: Stürenburg Enno , Kramer Jan , Schön Gerhard , Cachovan Georg , Sobottka Ingo 
Published: May 2014

ABSTRACT

In the microbiology laboratory, there is an augmented need for rapid screening methods for the detection of bacteria in urine samples, since about two-thirds of these samples will not yield any bacteria or will yield insignificant growth when cultured. Thus, a reliable screening method can free up laboratory resources and can speed up the reporting of a negative urine result. In this study, we have evaluated the detection of leukocytes, bacteria, and a new sediment indicator, the “all small particles” (ASP), by an automated instrument, the iQ200 urine analyzer, to detect negative urine samples that can be excluded from culture. A coupled automated strip reader (iChem Velocity), enabling the detection of nitrite and leukocyte esterase, was tested in parallel. In total, 963 urine samples were processed through both conventional urine culture and the iQ200/iChem Velocity workstation. Using the data, a multivariate regression model was established, and the predicted specificity and the possible reduction in urine cultures were calculated for the indicators and their respective combinations (leukocytes plus bacteria plus ASP and leukocyte esterase plus nitrite). Among all options, diagnostic performance was best using the whole microscopic content of the sample (leukocytes plus bacteria plus ASP). By using a cutoff value of ≥10
4
CFU/ml for defining a positive culture, a given sensitivity of 95% resulted in a specificity of 61% and a reduction in urine cultures of 35%. By considering the indicators alone, specificity and the culture savings were both much less satisfactory. The regression model was also used to determine possible cutoff values for running the instrument as part of daily routine. By using a graphical representation of all combinations possible, we derived cutoff values for leukocyte, bacterial, and ASP count, which should enable the iQ200 microscope to screen out approximately one-third of the urine samples, significantly reducing the workload in the microbiology laboratory.
Pseudo-Outbreak of Pre-Extensively Drug-Resistant (Pre-XDR) Tuberculosis in Kinshasa: Collateral Damage Caused by False Detection of Fluoroquinolone Resistance by GenoType MTBDR
sl
Authors: Kaswa Michel K. , Aloni Muriel , Nkuku Léontine , Bakoko Brian , Lebeke Rossin , Nzita Albert , Muyembe Jean Jacques , de Jong Bouke C. , de Rijk Pim , Verhaegen Jan , Boelaert Marleen , Ieven Margareta , Van Deun Armand 
Published: May 2014

ABSTRACT

Fluoroquinolones are the core drugs for the management of multidrug-resistant tuberculosis (MDR-TB). Molecular drug susceptibility testing methods provide considerable advantages for scaling up programmatic management and surveillance of drug-resistant TB. We describe here the misidentification of fluoroquinolone resistance by the GenoType MTBDR
sl
(MTBDR
sl
) (Hain Lifescience GmbH, Nehren, Germany) line probe assay (LPA) encountered during a feasibility and validation study for the introduction of this rapid drug susceptibility test in Kinshasa, Democratic Republic of Congo. The double
gyrA
mutation 80Ala and 90Gly represented 57% of all fluoroquinolone mutations identified from MDR-TB patient sputum samples, as confirmed by DNA sequencing. This double mutation was previously found to be associated with susceptibility to fluoroquinolones, yet it leads to absent hybridization of a wild-type band in the MTBDR
sl
and is thus falsely scored as resistance. Our findings suggest that MTBDR
sl
results must be interpreted with caution when the interpretation is based solely on the absence of a wild-type band without confirmation by visualization of a mutant band. Performance of the MTBDR
sl
LPA might be improved by replacing the
gyrA
wild-type probes by additional probes specific for well-documented
gyrA
mutations that confer clinically relevant resistance.
Cluster of Infections Caused by Methicillin-Resistant Staphylococcus pseudintermedius in Humans in a Tertiary Hospital
Authors: Starlander Gustaf , Börjesson Stefan , Grönlund-Andersson Ulrika , Tellgren-Roth Christian , Melhus Åsa 
Published: May 2014

ABSTRACT

The dog-associated
Staphylococcus pseudintermedius
is a rare pathogen in humans. Here we describe a cluster of infections caused by the methicillin-resistant
S. pseudintermedius
clone ST71-J-t02-II–III. It involved four elderly patients at a tertiary hospital. Three patients had wound infections, and the strain had a tendency to cause bullous skin lesions.
Disseminated Mycobacterium lentiflavum Responsible for Hemophagocytic Lymphohistocytosis in a Man with a History of Heart Transplantation
Authors: Thomas G. , Hraiech S. , Dizier S. , Weiller P. J. , Ene N. , Serratrice J. , Secq V. , Ambrosi P. , Drancourt M. , Roch A. , Papazian L. 
Published: May 2014

ABSTRACT

Mycobacterium lentiflavum
is a nontuberculous, slowly growing mycobacterium usually recognized as a contaminant. Here, we report a case of disseminated
M. lentiflavum
infection responsible for hemophagocytic lymphohistocytosis in a heart-transplanted man.
Clinical Utility of Droplet Digital PCR for Human Cytomegalovirus
Authors: Sedlak Ruth Hall , Cook Linda , Cheng Anqi , Magaret Amalia , Jerome Keith R. 
Published: May 2014

ABSTRACT

Human cytomegalovirus (CMV) has historically been the major infectious cause of morbidity and mortality among patients receiving hematopoietic cell or organ transplant. Standard care in a transplant setting involves frequent monitoring of CMV viral load over weeks to months to determine when antiviral treatment may be required. Quantitative PCR (qPCR) is the standard molecular diagnostic method for monitoring. Recently, digital PCR (dPCR) has shown promise in viral diagnostics, although current dPCR systems have lower throughput than qPCR systems. Here, we compare qPCR and droplet digital PCR (ddPCR) for CMV detection in patient plasma samples. Droplet digital PCR exhibits increased precision over qPCR at viral loads of ≥4 log
10
with equivalent sensitivity. However, retrospective analysis of longitudinal samples from transplant patients with CMV viral loads near therapeutic thresholds did not provide evidence that the improved precision of ddPCR would be of clinical benefit. Given the throughput advantages of current qPCR systems, a widespread switch to dPCR for CMV monitoring would appear premature.
Downregulation of Interleukin-18-Mediated Cell Signaling and Interferon Gamma Expression by the Hepatitis B Virus e Antigen
Authors: Jegaskanda S. , Ahn S. H. , Skinner N. , Thompson A. J. , Ngyuen T. , Holmes J. , De Rose R. , Navis M. , Winnall W. R. , Kramski M. , Bernardi G. , Bayliss J. , Colledge D. , Sozzi V. , Visvanathan K. , Locarnini S. A. , Kent S. J. , Revill P. A. 
Published: May 2014

ABSTRACTThe mechanisms by which hepatitis B virus (HBV) establishes and maintains chronic hepatitis B infection (CHB) are poorly defined. Innate immune responses play an important role in reducing HBV replication and pathogenesis. HBV has developed numerous mechanisms to escape these responses, including the production of the secreted hepatitis B e antigen (HBeAg), which has been shown to regulate antiviral toll-like receptor (TLR) and interleukin-1 (IL-1) signaling. IL-18 is a related cytokine that inhibits HBV replication in hepatoma cell lines and in the liver through the induction of gamma interferon (IFN-γ) by NK cells and T cells. We hypothesized that HBV or HBV proteins inhibit IFN-γ expression by NK cells as an accessory immunomodulatory function. We show that HBeAg protein inhibits the NF-κB pathway and thereby downregulates NK cell IFN-γ expression. Additionally, IFN-γ expression was significantly inhibited by exposure to serum from individuals with HBeAg-positive but not HBeAg-negative chronic HBV infection. Further, we show that the HBeAg protein suppresses IL-18-mediated NF-κB signaling in NK and hepatoma cells via modulation of the NF-κB pathway. Together, these findings show that the HBeAg inhibits IL-18 signaling and IFN-γ expression, which may play an important role in the establishment and/or maintenance of persistent HBV infection.IMPORTANCEIt is becoming increasingly apparent that NK cells play a role in the establishment and/or maintenance of chronic hepatitis B infection. The secreted HBeAg is an important regulator of innate and adaptive immune responses. We now show that the HBeAg downregulates NK cell-mediated IFN-γ production and IL-18 signaling, which may contribute to the establishment of infection and/or viral persistence. Our findings build on previous studies showing that the HBeAg also suppresses the TLR and IL-1 signaling pathways, suggesting that this viral protein is a key regulator of antiviral innate immune responses.
Activation of c-jun N-Terminal Kinase upon Influenza A Virus (IAV) Infection Is Independent of Pathogen-Related Receptors but Dependent on Amino Acid Sequence Variations of IAV NS1
Authors: Nacken Wolfgang , Anhlan Darisuren , Hrincius Eike R. , Mostafa Ahmed , Wolff Thorsten , Sadewasser Anne , Pleschka Stephan , Ehrhardt Christina , Ludwig Stephan 
Published: May 2014

ABSTRACT
A hallmark cell response to influenza A virus (IAV) infections is the phosphorylation and activation of c-jun N-terminal kinase (JNK). However, so far it is not fully clear which molecules are involved in the activation of JNK upon IAV infection. Here, we report that the transfection of influenza viral-RNA induces JNK in a retinoic acid-inducible gene I (RIG-I)-dependent manner. However, neither RIG-I-like receptors nor MyD88-dependent Toll-like receptors were found to be involved in the activation of JNK upon IAV infection. Viral JNK activation may be blocked by addition of cycloheximide and heat shock protein inhibitors during infection, suggesting that the expression of an IAV-encoded protein is responsible for JNK activation. Indeed, the overexpression of nonstructural protein 1 (NS1) of certain IAV subtypes activated JNK, whereas those of some other subtypes failed to activate JNK. Site-directed mutagenesis experiments using NS1 of the IAV H7N7, H5N1, and H3N2 subtypes identified the amino acid residue phenylalanine (F) at position 103 to be decisive for JNK activation. Cleavage- and polyadenylation-specific factor 30 (CPSF30), whose binding to NS1 is stabilized by the amino acids F103 and M106, is not involved in JNK activation. Conclusively, subtype-specific sequence variations in the IAV NS1 protein result in subtype-specific differences in JNK signaling upon IAV infection.

IMPORTANCE
Influenza A virus (IAV) infection leads to the activation or modulation of multiple signaling pathways. Here, we demonstrate for the first time that the c-jun N-terminal kinase (JNK), a long-known stress-activated mitogen-activated protein (MAP) kinase, is activated by RIG-I when cells are treated with IAV RNA. However, at the same time, nonstructural protein 1 (NS1) of IAV has an intrinsic JNK-activating property that is dependent on IAV subtype-specific amino acid variations around position 103. Our findings identify two different and independent pathways that result in the activation of JNK in the course of an IAV infection.
Progression From IgD+IgM+to Isotype-Switched B Cells Is Site Specific during Coronavirus-Induced Encephalomyelitis
Authors: Phares Timothy W. , DiSano Krista D. , Stohlman Stephen A. , Bergmann Cornelia C. 
Published: May 2014

ABSTRACTVarious infections in the central nervous system (CNS) trigger B cell accumulation; however, the relative dynamics between viral replication and alterations in distinct B cell subsets are largely unknown. Using a glia-tropic coronavirus infection, which is initiated in the brain but rapidly spreads to and predominantly persists in the spinal cord, this study characterizes longitudinal changes in B cell subsets at both infected anatomical sites. The phase of T cell-dependent, antibody-independent control of infectious virus was associated with a similar recruitment of naive/early-activated IgD+IgM+B cells into both the brain and spinal cord. This population was progressively replaced by CD138−IgD−IgM+B cells, isotype-switched CD138−IgD−IgM−memory B cells (Bmem), and CD138+antibody-secreting cells (ASC). A more rapid transition to Bmemand ASC in spinal cord than in brain was associated with higher levels of persisting viral RNA and transcripts encoding factors promoting B cell migration, differentiation, and survival. The results demonstrate that naive/early-activated B cells are recruited early during coronavirus CNS infection but are subsequently replaced by more differentiated B cells. Furthermore, viral persistence, even at low levels, is a driving force for accumulation of isotype-switched Bmemand ASC.IMPORTANCEAcute and chronic human CNS infections are associated with an accumulation of heterogeneous B cell subsets; however, their influence on viral load and disease is unclear. Using a glia-tropic coronavirus model, we demonstrate that the accumulation of B cells ranging from early-activated to isotype-switched differentiation stages is both temporally and spatially orchestrated. Acutely infected brains and spinal cords indiscriminately recruit a homogeneous population of early-activated B cells, which is progressively replaced by diverse, more differentiated subsets. The latter process is accelerated by elevated proinflammatory responses associated with viral persistence. The results imply that early-recruited B cells do not have antiviral function but may contribute to the inflammatory environment or act as antigen-presenting cells. Moreover, CNS viral persistence is a driving force promoting differentiated B cells with protective potential.
Nucleotide Oligomerization and Binding Domain 2-Dependent Dendritic Cell Activation Is Necessary for Innate Immunity and Optimal CD8+T Cell Responses to Influenza A Virus Infection
Authors: Lupfer Christopher , Thomas Paul G. , Kanneganti Thirumala-Devi 
Published: May 2014

ABSTRACTNucleotide oligomerization and binding domain (NOD)-like receptors (NLRs) are important in the innate immune response to viral infection. Recent findings have implicated NLRP3, NOD2, and NLRX1 as important players in the innate antiviral response, but their roles in the generation of adaptive immunity to viruses are less clear. We demonstrate here that NOD2 is critical for both innate and adaptive immune responses necessary for controlling viral replication and survival during influenza A virus (IAV) infection.Nod2−/−mice have reduced beta interferon (IFN-β) levels and fewer activated dendritic cells (DCs), and the DCs are more prone to cell death in the lungs ofNod2−/−mice during IAV infection. In agreement with the role for DCs in priming adaptive immunity, the generation of virus-specific CD8+T cells and their activation and production of IFN-γ were lower inNod2−/−mice. Furthermore,Nod2−/−DCs, when cocultured with T cellsin vitro, have a lower costimulatory capacity. Thus,Nod2−/−DCs are unable to efficiently prime CD8+T cells. These findings demonstrate that Nod2 is critical for the generation of both innate and adaptive immune responses necessary for controlling IAV infection.IMPORTANCEThe innate immune system is the host's first line of defense against invading pathogens and is also necessary for alerting and activating T and B cells to initiate the adaptive immune response. We demonstrate here that the innate immune receptor NOD2 is required for the production of antiviral type I interferons and the activation and survival of dendritic cells that, in turn, alert T cells to the presence of influenza A virus infection. In mice that are missing NOD2, interferon levels are lower, and the CD8+T cell response is impaired. As a result, the animals cannot control virus replication in their lungs as efficiently. This discovery helps us understand how the body naturally responds to virus infection and may help in the development of vaccines that use NOD2 to stimulate the CD8+T cell response, thus providing better protection against influenza A virus infection.