Clinical utility of measuring Epstein –Barr virus-specific cell-mediated immunity after HSCT in addition to virological monitoring: results from a prospective study
AbstractLack of virus-specific cell-mediated immunity (CMI) is associated with worse viral infection outcome in hematopoietic stem cell transplantation (HSCT). We aimed to evaluate the role of immunological monitoring of Epstein –Barr virus (EBV) infection in addition to virological one in 33 adult and 18 pediatric allogeneic HSCT recipients. Virological monitoring of infection was performed on whole blood samples by a quantitative real-time PCR assay. Immunological monitoring was performed by Enzyme-linked ImmunoSPOT ass ay, evaluating EBV-specific CMI, at fixed time-points and when EBV DNAemia was ≥&thins...
Source: Medical Microbiology and Immunology - July 9, 2019 Category: Microbiology Source Type: research

Interplay between IDO1 and iNOS in human retinal pigment epithelial cells
In conclusion, iNOS mediates anti-inflammatory effects in hRPE cells stimulated with high amounts of IFN- γ together with tumor necrosis factor alpha and Interleukin-1 beta and prevents potential IDO1-dependent tissue damage. (Source: Medical Microbiology and Immunology)
Source: Medical Microbiology and Immunology - July 2, 2019 Category: Microbiology Source Type: research

Role of coaggregation in the pathogenicity and prolonged colonisation of Vibrio cholerae
AbstractCholera is an acute diarrheal illness caused by the Gram-negative bacteriumVibrio cholerae. The pathogen is known for its ability to form biofilm that confers protection against harsh environmental condition and as part of the colonisation process during infection. Coaggregation is a process that facilitates the formation of biofilm. In a preliminary in vitro study, high coaggregation index and biofilm production were found betweenV. cholerae with human commensals namelyEscherichia coli andEnterobacter cloacae. Building upon these results, the effects of coaggregation were further evaluated using adult BALB/c mouse...
Source: Medical Microbiology and Immunology - July 1, 2019 Category: Microbiology Source Type: research

Correction to: Seroprevalence of hepatitis E virus (HEV) in a general adult population in Northern Norway: the Troms ø study
Unfortunately, the supplement tables are missing in the original article. The missing files have been included here. (Source: Medical Microbiology and Immunology)
Source: Medical Microbiology and Immunology - June 22, 2019 Category: Microbiology Source Type: research

In vitro activity of Protegrin-1, alone and in combination with clinically useful antibiotics, against Acinetobacter baumannii strains isolated from surgical wounds
This study examines the antimicrobial and antibiofilm activity of protegrin 1 (PG-1), an antimicrobial peptide from porcine leukocytes, againstA. baumannii strains isolated from surgical wounds. PG-1 was tested both alone and combined with the antibiotics commonly used in clinical settings. Its antimicrobial activity was evaluated by determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), checkerboard assays, and time-kill experiments. Its effects on biofilm inhibition/eradication were tested with crystal violet staining. The strains were grown in subinhibitory or increasing PG...
Source: Medical Microbiology and Immunology - June 18, 2019 Category: Microbiology Source Type: research

The T cell activating properties and antitumour activity of Staphylococcal Enterotoxin-like Q
AbstractStaphylococcal enterotoxins (SEs), as typical superantigens, exhibit promising antitumour activity in the clinic, but their unavoidable side effects related to fever and emesis seriously limit their application for the treatment of malignant tumours. Fortunately, the identification of Staphylococcal enterotoxin-like toxins (SEls), which possess amino acid sequences similar to those of classical SEs but exhibit no or low emetic activity, has provided a set of potential immunomodulatory candidates for cancer therapy. The aim of this study was to examine the effect of SElQ on lymphocyte activation and to further demon...
Source: Medical Microbiology and Immunology - June 11, 2019 Category: Microbiology Source Type: research

Rapid differential diagnosis of vaginal infections using gold nanoparticles coated with specific antibodies
AbstractVaginal infections caused by bacteria, Candida andTrichomonas vaginalis, affect millions of women annually worldwide. Symptoms and signs have limited value in differential diagnosis of three causes of vaginitis. Current laboratory methods for differential diagnosis are either expensive or time consuming. Therefore, in this work, development of a method based on gold nanoparticles has been investigated for rapid diagnosis of vaginal infections. Specific antibodies against three main causes of vaginal infections were raised in rabbits. The antibodies were then purified and conjugated to gold nanoparticles and used in...
Source: Medical Microbiology and Immunology - June 10, 2019 Category: Microbiology Source Type: research

Correction to: T-cell aging in end-stage renal disease: an evolving story with CMV
Unfortunately in the original article the first author name incorrectly published as TienYu Yang. The correct name is TienYu Owen Yang. (Source: Medical Microbiology and Immunology)
Source: Medical Microbiology and Immunology - June 9, 2019 Category: Microbiology Source Type: research

Defective interferon priming and impaired antiviral responses in a patient with an IRF7 variant and severe influenza
AbstractInfluenza infection is common worldwide with many individuals affected each year during epidemics and occasionally pandemics. Previous studies in animal models and a few human cases have established an important role of innate type I and III interferon (IFN) for viral elimination and mounting of antiviral responses. However, genetic and immunological determinants of very severe disseminated influenza  virus infection in humans remain incompletely understood. Here, we describe an adult patient with severe influenza virus A (IAV) infection, in whom we identified a rare variant E331V in IFN regulatory factor...
Source: Medical Microbiology and Immunology - June 6, 2019 Category: Microbiology Source Type: research

Genetic variability of human papillomavirus type 66 L1 gene among women presenting for cervical cancer screening in Chile
AbstractThe high-risk human papillomaviruses (HR-HPVs) are involved in the development of cervical cancer. Nevertheless, there are differences in the oncogenic potential among them. HPV-16 and HPV-18 are associated with approximately 70% of cancer worldwide, and both types are the most extensively studied HR-HPV. Great variations in the prevalence of HR-HPV have been described in different countries. The impact of these variations on the epidemiology of lesions and cervical cancer is currently unknown. A high prevalence of HPV-66 has been detected in Chile. Here, we have analyzed the genetic variability of the L1 gene f...
Source: Medical Microbiology and Immunology - June 4, 2019 Category: Microbiology Source Type: research

Influence of Hepatitis C virus coinfection on immune reconstitution in HIV subjects
In this study, we investigated the presence of immune activation in a cohort of 50 HIV/HCV patients by measuring cytokine levels, CD4+ T-cell counts and CD4/CD8 ratios. Six patient groups were defined according to HIV viral load, HCV status, and liver disease to assess the impact of each of these factors on immune activation and reconstitution in HIV/HCV patients. Only subjects with controlled HIV infection and cleared HCV displayed immunological parameters within normal ranges. The mere presence of HCV contributes to immune activation leading to an inappropriate immunological reconstitution. This state exacerbates in the ...
Source: Medical Microbiology and Immunology - May 30, 2019 Category: Microbiology Source Type: research

‘Checks and balances’ in cytomegalovirus-host cohabitation
(Source: Medical Microbiology and Immunology)
Source: Medical Microbiology and Immunology - May 25, 2019 Category: Microbiology Source Type: research

Caspase-8 restricts natural killer cell accumulation during MCMV Infection
AbstractNatural killer (NK) cells provide important host defense against herpesvirus infections and influence subsequent T cell control of replication and maintenance of latency. NK cells exhibit phases of expansion, contraction and memory formation in response to the natural mouse pathogen murine cytomegalovirus (MCMV). Innate and adaptive immune responses are tightly regulated in mammals to avoid excess tissue damage while preventing acute and chronic viral disease and assuring resistance to reinfection. Caspase (CASP)8 is an autoactivating aspartate-specific cysteine protease that initiates extrinsic apoptosis and preve...
Source: Medical Microbiology and Immunology - May 21, 2019 Category: Microbiology Source Type: research

Caspase-8-dependent control of NK- and T cell responses during cytomegalovirus infection
AbstractCaspase-8 (CASP8) impacts antiviral immunity in expected as well as unexpected ways. Mice with combined deficiency in CASP8 and RIPK3 cannot support extrinsic apoptosis or RIPK3-dependent programmed necrosis, enabling studies of CASP8 function without complications of unleashed necroptosis. These extrinsic cell death pathways are naturally targeted by murine cytomegalovirus (MCMV)-encoded cell death suppressors, showing they are key to cell-autonomous host defense. Remarkably,Casp8–/–Ripk3–/–,Ripk1–/–Casp8–/–Ripk3–/– andCasp8–/–Ripk3K51A/K51A m...
Source: Medical Microbiology and Immunology - May 16, 2019 Category: Microbiology Source Type: research

Adverse immunological imprinting by cytomegalovirus sensitizing for allergic airway disease
AbstractCytomegalovirus (CMV) infection has a profound impact on the host ’s immune system. Immunological imprinting by CMV is not restricted to immunity against CMV itself, but can affect immunity against other viral or non-viral infectious agents and also immunopathological responses. One category is heterologous immunity based on molecular mimicry, where antigen reco gnition receptors specific for a CMV antigen with broad avidity distribution also bind with some avidity to unrelated antigens and exert effector functions against target structures other than those linked to CMV. Another category is induction of cyto...
Source: Medical Microbiology and Immunology - May 10, 2019 Category: Microbiology Source Type: research

Survey of cellular immune responses to human cytomegalovirus infection in the microenvironment of the uterine –placental interface
AbstractCongenital human cytomegalovirus (HCMV) infection is a leading cause of birth defects, yet there are no established treatments for preventing maternal –fetal transmission. During first trimester, HCMV replicates in basal decidua that functions as a reservoir for virus and source of transmission to the attached placenta and fetal hemiallograft but also contains immune cells, including natural killer cells, macrophages, and T cell subsets, that re spond to pathogens, protecting the placenta and fetus. However, the specific cellular and cytokine responses to infection are unknown, nor are the immune correlates o...
Source: Medical Microbiology and Immunology - May 7, 2019 Category: Microbiology Source Type: research

Pediatric roots of cytomegalovirus recurrence and memory inflation in the elderly
AbstractThe establishment of a lifelong latent infection after resolution of primary infection is a hallmark of cytomegalovirus (CMV) biology. Primary infection with human CMV is possible any time in life, but most frequently, virus transmission occurs already perinatally or in early childhood. Many years or even decades later, severe clinical problems can result from recurrence of infectious virus by reactivation from latency in individuals who undergo immunocompromising medical treatment, for instance, transplant recipients, but also in septic patients without canonical immunosuppression, and in elderly people with a wea...
Source: Medical Microbiology and Immunology - May 6, 2019 Category: Microbiology Source Type: research

‘From immunosenescence to immune modulation’: a re-appraisal of the role of cytomegalovirus as major regulator of human immune function
AbstractIn the year 2000, cytomegalovirus was identified as a risk factor for mortality in a seminal study of octogenarian residents in Sweden. This finding triggered a wave of additional epidemiological investigations, some of which supported this association whilst others observed no such effect. In addition, this increased risk of death in CMV-seropositive people was correlated with observed changes within the T-cell repertoire such that accelerated ‘immunosenescence’ became a de facto explanation, without strong evidence to this effect. Recent years have seen a re-appraisal of these findings. Interestingly,...
Source: Medical Microbiology and Immunology - May 3, 2019 Category: Microbiology Source Type: research

Immunological evaluation of two novel engineered Plasmodium vivax circumsporozoite proteins formulated with different human-compatible vaccine adjuvants in C57BL/6 mice
In this study, in vivo immunological evaluation of two novel engineered proteins ofP. vivax circumsporozoite (PvCS127 and PvCS712) with two different arrangements of the repeat sequences of VK210 and VK247 was assessed. The immunological properties of theEscherichia coli-expressed chimeric proteins were evaluated by the immunization of C57BL/6 mice administered in NLX, CpG-ODNs, and QS21, alone or in combination as adjuvants. A significant increase in anti-rPvCS127 and -rPvCS712 IgG antibodies was observed in all the vaccine groups after the first boost, and the predominant isotypes were high-avidity cytophilic antibodies,...
Source: Medical Microbiology and Immunology - April 25, 2019 Category: Microbiology Source Type: research

Cellular reservoirs of latent cytomegaloviruses
AbstractCytomegaloviruses (CMVs), members of the β-subfamily of the herpesvirus family, have co-speciated with their respective mammalian hosts resulting in a mutual virus–host adaptation reflected by sets of ‘private’ viral genes that a particular CMV species does not share with other CMVs and that define the host-species specificity of CM Vs. Nonetheless, based on “biological convergence” in evolution, fundamental rules in viral pathogenesis and immune control are functionally analogous between different virus–host pairs. Therefore, the mouse model of infection with murine CMV (mC...
Source: Medical Microbiology and Immunology - April 22, 2019 Category: Microbiology Source Type: research

Transcripts expressed in cytomegalovirus latency coding for an antigenic IE/E phase peptide that drives “memory inflation”
AbstractRoizman ’s definition of herpesviral latency, which applies also to cytomegaloviruses (CMVs), demands maintenance of reactivation-competent viral genomes after clearance of productive infection. It is more recent understanding that failure to complete the productive viral cycle for virus assembly and rele ase does not imply viral gene silencing at all genetic loci and all the time. It rather appears that CMV latency is transcriptionally “noisy” in that silenced viral genes get desilenced from time to time in a stochastic manner, leading to “transcripts expressed in latency” (TELs). If ...
Source: Medical Microbiology and Immunology - April 19, 2019 Category: Microbiology Source Type: research

Function of the cargo sorting dileucine motif in a cytomegalovirus immune evasion protein
AbstractAs an immune evasion mechanism, cytomegaloviruses (CMVs) have evolved proteins that interfere with cell surface trafficking of MHC class-I (MHC-I) molecules to tone down recognition by antiviral CD8 T cells. This interference can affect the trafficking of recently peptide-loaded MHC-I from the endoplasmic reticulum to the cell surface, thus modulating the presentation of viral peptides, as well as the recycling of pre-existing cell surface MHC-I, resulting in reduction of the level of overall MHC-I cell surface expression. Murine cytomegalovirus (mCMV) was paradigmatic in that it led to the discovery of this immune...
Source: Medical Microbiology and Immunology - April 19, 2019 Category: Microbiology Source Type: research

Impact of CMV upon immune aging: facts and fiction
AbstractAging is accompanied by significant defects in immunity and compromised responses to new, previously unencountered microbial pathogens. Most humans carry several persistent or latent viruses as they age, interacting with the host immune systems for years. In that context maybe the most studied persistent virus is Cytomegalovirus, infamous for its ability to recruit very large T cell responses which increase with age and to simultaneously evade elimination by the immune system. Here we will address how lifelong CMV infection and the immunological burden of its control might affect immune reactivity and health of the...
Source: Medical Microbiology and Immunology - April 19, 2019 Category: Microbiology Source Type: research

The hallmarks of CMV-specific CD8 T-cell differentiation
AbstractUpon cytomegalovirus (CMV) infection, large T-cell responses are elicited that remain high or even increase over time, a phenomenon named memory T-cell inflation. Besides, the maintained robust T-cell response, CMV-specific T cells seem to have a distinctive phenotype, characterized by an advanced differentiation state. Here, we will review this “special” differentiation status by discussing the cellular phenotype based on the expression of CD45 isoforms, costimulatory, inhibitory and natural killer receptors, adhesion and lymphocyte homing molecules, transcription factors, cytokines and cytotoxic molec...
Source: Medical Microbiology and Immunology - April 13, 2019 Category: Microbiology Source Type: research

Impact of cytomegalovirus load on host response to sepsis
AbstractThere is a decades old association between cytomegalovirus reactivation and sepsis in immune-competent hosts. Much has been learned about this relationship, which has been described as bidirectional, meaning that the virus incites and is incited by the host ’s inflammatory response. More recent work has suggested that chronic viral infection leaves the host with exaggerated immunity to bacterial infections. In this review, the relationship between CMV and host responses to sepsis are reviewed, with particular attention to the impact that tissue viral load contributes to this phenomenon. (Source: Medical Micro...
Source: Medical Microbiology and Immunology - April 11, 2019 Category: Microbiology Source Type: research

Serum cytokine and chemokine changes during Toscana virus meningitis
AbstractToscana virus is an important arbovirus causing meningitis and meningoencephalitis in countries around the Mediterranean Sea. While the clinical syndrome and laboratory diagnostic procedures have been well described, less is known about the immune response in Toscana virus meningitis and a possible use of cytokine and chemokine changes for the clinical follow-up of patients. We here characterized serum cytokine and chemokine profiles from 37 patients during the acute and convalescent phase of the infection. Only few serum cytokine/chemokine changes were detected during Toscana virus meningitis. Markedly increased c...
Source: Medical Microbiology and Immunology - April 11, 2019 Category: Microbiology Source Type: research

Cytomegalovirus memory inflation and immune protection
AbstractCytomegalovirus (CMV) infection induces powerful and sustained T-cell responses against a few selected immunodominant antigenic epitopes. This immune response was named memory inflation, because it does not contract in the long term, and may even expand over months and years of virus latency. It is by now understood that memory inflation does not occur at the expense of the na ïve T-cell pool, but rather as a competitive selection process within the effector pool, where viral antigens with higher avidity of TCR binding and with earlier expression patterns outcompete those that are expressed later and bind TCRs...
Source: Medical Microbiology and Immunology - April 10, 2019 Category: Microbiology Source Type: research

Effect of latent cytomegalovirus infection on the antibody response to influenza vaccination: a systematic review and meta-analysis
In conclusion, by systematically integrating the available studies, we show that there is no unequivocal evidence that latent CMV infection affects the influenza antibody response to vaccination. Further studies, including the level of CMV antibodies, are required to settle on the potential influence of latent CMV infection on the influenza vaccine response. (Source: Medical Microbiology and Immunology)
Source: Medical Microbiology and Immunology - April 4, 2019 Category: Microbiology Source Type: research

CD4 T cells are required for maintenance of CD8 T RM cells and virus control in the brain of MCMV-infected newborn mice
AbstractCytomegalovirus (CMV) infection is a significant public health problem. Congenital CMV infection is a leading infectious cause of long-term neurodevelopmental sequelae, including mental retardation and sensorineural hearing loss. Immune protection against mouse cytomegalovirus (MCMV) is primarily mediated by NK cells and CD8+ T cells, while CD4+ T cells are not needed for control of MCMV in majority of organs in immunocompetent adult mice. Here, we set out to determine the role of CD4+ T cells upon MCMV infection of newborn mice. We provide evidence that CD4+ T cells are essential for clearance of MCMV infection in...
Source: Medical Microbiology and Immunology - March 28, 2019 Category: Microbiology Source Type: research

Role of antibodies in confining cytomegalovirus after reactivation from latency: three decades ’ résumé
AbstractCytomegaloviruses (CMVs) are highly prevalent herpesviruses, characterized by strict species specificity and the ability to establish non-productive latent infection from which reactivation can occur. Reactivation of latent human CMV (HCMV) represents one of the most important clinical challenges in transplant recipients secondary to the strong immunosuppression. In addition, HCMV is the major viral cause of congenital infection with severe sequelae including brain damage. The accumulated evidence clearly shows that cellular immunity plays a major role in the control of primary CMV infection as well as establishmen...
Source: Medical Microbiology and Immunology - March 28, 2019 Category: Microbiology Source Type: research

Kinetics of inflammatory biomarkers in plasma predict the occurrence and features of cytomegalovirus DNAemia episodes in allogeneic hematopoietic stem cell transplant recipients
AbstractCytomegalovirus (CMV) DNAemia occurs frequently in CMV-seropositive allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients, and usually results from reactivation of latent infection established in the recipient. Predicting the occurrence of CMV DNAemia may be helpful in managing CMV infection in allo-HSCT recipients. Here, the kinetics of several inflammatory biomarkers in plasma were characterized and assessed for their potential value in anticipating the development and features of active CMV infection in allo-HSCT recipients, as documented using real-time PCR assays. The cohort consisted of 46 non-...
Source: Medical Microbiology and Immunology - March 25, 2019 Category: Microbiology Source Type: research

Seroprevalence of hepatitis E virus (HEV) in a general adult population in Northern Norway: the Troms ø study
AbstractHepatitis E virus (HEV) is a major cause of acute viral hepatitis in many parts of the world but only a few cases have been diagnosed in Norway. To investigate the HEV exposure rate in a presumed low-risk area, we have conducted a population-based study of anti-HEV IgG seroprevalence in Northern Norway. A total of 1800 serum samples from 900 women and 900 men, age 40 –79 years, were randomly selected from the 21,083 participants in the 7th Tromsø Study, representing the 32,591 inhabitants of the Tromsø municipality that were ≥ 40 years. All samples were analyzed by ELISA-1 (r...
Source: Medical Microbiology and Immunology - March 22, 2019 Category: Microbiology Source Type: research

T-cell aging in end-stage renal disease: an evolving story with CMV
AbstractEstablished evidence from the last decade has suggested that chronic cytomegalovirus infection has strong impact on the human immune system, resulting in aggravated aging-associated T-cell changes that are associated with poorer vaccination responses, cardiovascular disease and shortened survival. Patients with end-stage renal disease (ESRD), the most severe form of chronic kidney disease, exhibit premature aging phenotypes in almost all organ systems, including the immune system. Longitudinal studies of T-cell aging in healthy humans have been scanty because it requires a large number of study subjects and a study...
Source: Medical Microbiology and Immunology - March 21, 2019 Category: Microbiology Source Type: research

Emerging roles of cytomegalovirus-encoded G protein-coupled receptors during lytic and latent infection
AbstractCytomegaloviruses (CMVs) have developed multiple diverse strategies to ensure their replicative success and to evade immune recognition. Given the fact that G protein-coupled receptors (GPCRs) are key regulators of numerous cellular processes and modify a variety of signaling pathways, it is not surprising that CMVs and other herpesviruses have hijacked mammalian GPCRs during their coevolution. Human cytomegalovirus (HCMV) encodes for four viral GPCR homologues (vGPCRs), termed US27, US28, UL33, and UL78. Although HCMV-encoded GPCRs were first described in 1990, the pivotal functions of these viral receptor protein...
Source: Medical Microbiology and Immunology - March 21, 2019 Category: Microbiology Source Type: research

Vaccine vectors: the bright side of cytomegalovirus
AbstractCytomegaloviruses (CMVs) present singular features that are particularly advantageous for human vaccine development, a current medical need. Vaccines that induce neutralizing antibodies are among the most successful and efficacious available. However, chronic and persistent human infections, pathogens with high variability of exposed proteins, as well as tumors, highlight the need for developing novel vaccines inducing strong and long-lasting cellular immune responses mediated by effector or effector memory CD8+ cytotoxic T lymphocytes. CMVs induce the most potent CD8+ T lymphocyte response to a pathogen known in e...
Source: Medical Microbiology and Immunology - March 21, 2019 Category: Microbiology Source Type: research

T-cell immunity against cytomegalovirus in HIV infection and aging: relationships with inflammation, immune activation, and frailty
AbstractBoth aging and treated human immunodeficiency virus (HIV) infection are characterized by low-level chronic inflammation and immune activation which contribute to the development of age-related diseases, frailty, and early mortality. Chronic cytomegalovirus (CMV) infection is highly prevalent in older adults and HIV-infected populations. A number of studies have shown that CMV induces broad and strong T-cell responses in CMV-seropositive older adults and HIV-infected individuals. CMV infection rarely develops into clinical disease in immunocompetent individuals. However, a large body of literature has shown adverse ...
Source: Medical Microbiology and Immunology - March 21, 2019 Category: Microbiology Source Type: research

Generation, maintenance and tissue distribution of T cell responses to human cytomegalovirus in lytic and latent infection
AbstractUnderstanding how the T cell memory response directed towards human cytomegalovirus (HCMV) develops and changes over time while the virus persists is important. Whilst HCMV primary infection and periodic reactivation is well controlled by T cell responses in healthy people, when the immune system is compromised such as post-transplantation, during pregnancy, or underdeveloped such as in new-born infants and children, CMV disease can be a significant problem. In older people, HCMV infection is associated with increased risk of mortality and despite overt disease rarely being seen there are increases in HCMV-DNA in u...
Source: Medical Microbiology and Immunology - March 20, 2019 Category: Microbiology Source Type: research

Innate immune response in patients with acute Zika virus infection
In this study, we evaluated the mRNA expression of innate immune receptors (TLR3, TLR7, TLR8, TLR9, melanoma differentiation-associated protein 5/MDA-5, and reti noic acid inducible gene/RIG-1), its adapter molecules (Myeloid Differentiation Primary Response Gene 88/Myd88,Toll/IL-1 Receptor Domain-Containing Adaptor-Inducing IFN- β/TRIF), and cytokines (IL-6, IL-12, TNF-α, IFN-α, IFN-β, and IFN-γ) in the acute phase of patients infected by ZIKV using real-time PCR in peripheral blood. Patients with acute ZIKV infection had high expression of TLR3, IFN-α, IFN-β, and IFN-γ when co...
Source: Medical Microbiology and Immunology - March 16, 2019 Category: Microbiology Source Type: research

Intertwined: SAMHD1 cellular functions, restriction, and viral evasion strategies
AbstractSAMHD1 was initially described for its ability to efficiently restrict HIV-1 replication in myeloid cells and resting CD4+ T cells. However, a growing body of evidence suggests that SAMHD1-mediated restriction is by far not limited to lentiviruses, but seems to be a general concept that applies to most retroviruses and at least a number of DNA viruses. SAMHD1 anti-viral activity was long believed to be solely due to its ability to deplete cellular dNTPs by enzymatic degradation. However, since its discovery, several new functions have been attributed to SAMHD1. It has been demonstrated to bind nucleic acids, to mod...
Source: Medical Microbiology and Immunology - March 16, 2019 Category: Microbiology Source Type: research

Discrimination between recent and non-recent HIV infections using routine diagnostic serological assays
AbstractThe suitability of routine diagnostic HIV assays to accurately discriminate between recent and non-recent HIV infections has not been fully investigated. The aim of this study was to compare an established HIV recency assay, the Sedia limiting antigen HIV avidity assay (LAg), with the diagnostic assays; Abbott ARCHITECT HIV Ag/Ab Combo and INNO-LIA HIV line assays. Samples from all new HIV diagnoses in Ireland from January to December 2016 (n = 455) were tested. An extended logistic regression model, the Spiegelhalter–Knill–Jones method, was utilised to establish a scoring system to predic...
Source: Medical Microbiology and Immunology - March 11, 2019 Category: Microbiology Source Type: research

Kinetics of Alphatorquevirus plasma DNAemia at late times after allogeneic hematopoietic stem cell transplantation
AbstractTorque teno virus (TTV) plasma DNA load has been consistently shown to be a surrogate biomarker of immunosuppression in solid organ transplant recipients. It is uncertain whether it may behave similarly in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). Here, we characterized the dynamics of TTV DNAemia in patients undergoing T-cell replete allo-SCT at late times after transplantation (>  day + 100). This retrospective single-center observational study included 33 allo-HSCT patients. Plasma TTV DNA loads were quantified by real-time PCR before initiating the conditionin...
Source: Medical Microbiology and Immunology - March 9, 2019 Category: Microbiology Source Type: research

Fuel and brake of memory T cell inflation
AbstractMemory T cell inflation is a process in which a large number of effector memory T cells accumulates in peripheral tissues. This phenomenon is observed upon certain low level persistent virus infections, but it is most commonly described upon infection with the β-herpesvirus Cytomegalovirus. Due to the induction of this large pool of functional effector CD8 T cells in peripheral tissues, the interest in using CMV-based vaccine vectors for vaccination purposes is rising. However, the exact mechanisms of memory T cell inflation are not yet fully understood. It is clear that repetitive exposure to antigen is a key...
Source: Medical Microbiology and Immunology - March 9, 2019 Category: Microbiology Source Type: research

High polymorphism rates in well-known T cell epitopes restricted by protective HLA alleles during HIV infection are associated with rapid disease progression in early-infected MSM in China
AbstractT cell epitopes restricted by several protective HLA alleles, such as B*57, B*5801, B*27, B*51 and B*13, have been very well defined over the past two decades. We investigated 32 well-known T cell epitopes restricted by protective HLA molecules among 54 Chinese men who have sex with men (MSM) at the early stage of HIV-1 infection. Subjects in our cohort carrying protective HLA types did not exhibit slow CD4 T cell count decline (P = 0.489) or low viral load set points (P = 0.500). Variations occurred in 96.88% (31/32) of the known wild-type epitopes (rate 1.85–100%), and the variat...
Source: Medical Microbiology and Immunology - March 8, 2019 Category: Microbiology Source Type: research

Persistent viral replication and the development of T-cell responses after intranasal infection by MCMV
AbstractNatural transmission of cytomegalovirus (CMV) has been difficult to observe. However, recent work using the mouse model of murine (M)CMV demonstrated that MCMV initially infects the nasal mucosa after transmission from mothers to pups. We found that intranasal (i.n.) inoculation of C57BL/6J mice resulted in reliable recovery of replicating virus from the nasal mucosa as assessed by plaque assay. After i.n. inoculation, CD8+ T-cell priming occurred in the mandibular, deep-cervical, and mediastinal lymph nodes within 3  days of infection. Although i.n. infection induced “memory inflation” of T cells ...
Source: Medical Microbiology and Immunology - March 8, 2019 Category: Microbiology Source Type: research

Genetic variation and function of the HIV-1 Tat protein
AbstractHuman immunodeficiency virus type 1 (HIV-1) encodes a transactivator of transcription (Tat) protein, which has several functions that promote viral replication, pathogenesis, and disease. Amino acid variation within Tat has been observed to alter the functional properties of Tat and, depending on the HIV-1 subtype, may produce Tat phenotypes differing from viruses ’ representative of each subtype and commonly used in in vivo and in vitro experimentation. The molecular properties of Tat allow for distinctive functional activities to be determined such as the subcellular localization and other intracellular and...
Source: Medical Microbiology and Immunology - March 5, 2019 Category: Microbiology Source Type: research

Coevolution pays off: Herpesviruses have the license to escape the DNA sensing pathway
AbstractEarly detection of viral invasion by pattern recognition receptors (PRR) is crucial for the induction of a rapid and efficient immune response. Cytosolic DNA sensors are the most recently described class of PRR, and induce transcription of type I interferons (IFN) and proinflammatory cytokines via the key adaptor protein stimulator of interferon genes (STING). Herpesviruses are a family of large DNA viruses widely known for their immense arsenal of proteins dedicated to manipulating and evading host immune responses. Tantamount to the significant role played by DNA sensors and STING in innate immune responses, herp...
Source: Medical Microbiology and Immunology - February 25, 2019 Category: Microbiology Source Type: research

Conserved peptide vaccine candidates containing multiple Ebola nucleoprotein epitopes display interactions with diverse HLA molecules
AbstractImmunoinformatics has come by leaps and bounds to finding potent vaccine candidates against various pathogens. In the current study, a combination of different T (CD4+ and CD8+) and B cell epitope prediction tools was applied to find peptides containing multiple epitopes against Ebola nucleoprotein (NP) and the presentation of peptides to human leukocyte antigen (HLA) molecules was analyzed by prediction, docking and population coverage tools. Further, potential peptides were analyzed by ELISA for peptide induced IFN- γ secretion in peripheral blood mononuclear cells isolated from healthy volunteers. Six pept...
Source: Medical Microbiology and Immunology - February 21, 2019 Category: Microbiology Source Type: research

HCMV latency: what regulates the regulators?
AbstractHuman cytomegalovirus (HCMV) latency and reactivation is regulated by the chromatin structure at the major immediate early promoter (MIEP) within myeloid cells. Both cellular and viral factors are known to control this promoter during latency, here we will review the known mechanisms for MIEP regulation during latency. We will then focus on the virally encoded G-protein coupled receptor, US28, which suppresses the MIEP in early myeloid lineage cells. The importance of this function is underlined by the fact that US28 is essential for HCMV latency in CD34+ progenitor cells and CD14+ monocytes. We will describe cellu...
Source: Medical Microbiology and Immunology - February 14, 2019 Category: Microbiology Source Type: research

Comparison of four adjuvants revealed the  strongest protection against lethal pneumococcal challenge following immunization with PsaA-PspA fusion protein and AS02 as adjuvant
In this study, the fusion protein PsaA-PspA23, together with PspA4, was formulated with four adjuvants Al(OH)3, MF59, AS03, and AS02, and subsequently subjected to dose optimization and immunological evaluation for determination of the antibody titers, bacterial burden, survival rates, and levels of cytokines in mice. All vaccines with high adjuvant doses displayed higher antigen-specific immunoglobulin G (IgG) titers. Bacterial burdens were notably decreased to different extents in the lungs and blood of mice immunized with the antigen and various adjuvants. Among these adjuvants, AS02 provided outstanding protection agai...
Source: Medical Microbiology and Immunology - February 1, 2019 Category: Microbiology Source Type: research

Secretory IgA-mediated immune response in saliva and early detection of Pseudomonas aeruginosa in the lower airways of pediatric cystic fibrosis patients
AbstractPseudomonas aeruginosa (Pa) detection in the paranasal sinuses may help to prevent or postpone bacterial aspiration to the lower airways (LAW) and chronic lung infection in cystic fibrosis (CF). We assessed the ability of an ELISA test for measurement of specificPa secretory IgA (sIgA) in saliva (a potential marker of sinus colonization) to early detect changes in thePa LAW status (indicated by microbiological sputum or cough swab culture and specific serum IgG levels) of 65 patients for three  years, in different investigation scenarios. Increased sIgA levels were detected in saliva up to 22 months befor...
Source: Medical Microbiology and Immunology - January 31, 2019 Category: Microbiology Source Type: research