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Medicines (Basel, Switzerland) Apr 2020Epstein-Barr virus (EBV) infection is associated with significant morbidity and mortality in renal transplant (RT) recipients. The spectrum of illness ranges from...
Epstein-Barr virus (EBV) infection is associated with significant morbidity and mortality in renal transplant (RT) recipients. The spectrum of illness ranges from infectious mononucleosis (IM) to post-transplant lymphoproliferative disorder (PTLD). In association with clinical signs and symptoms, virus-specific serology and heterophile antibody tests are widely used in confirming the diagnosis of IM in the general population. However, these tests may have a limited role in immunosuppressed RT recipients from seropositive donor, especially in children who were EBV-seronegative prior to the transplant. The aim of this study is to evaluate the utility of these tests in the early diagnosis of IM in this subset of patients. This is a case study with a review of literature. Here, we present a 14-year-old male with hemophilia B who presented with fever, fatigue, sore throat, palatal petechial rash, exudative tonsillitis and cervical lymphadenopathy 3 months post-RT. He was EBV seronegative prior to RT and received a deceased donor kidney transplant from a seropositive donor. Induction was done with Thymoglobulin and maintenance immunosuppression consisted of tacrolimus and mycophenolate. Initial heterophile antibody test (monospot) was negative, but became positive at 5 months and remained positive at 9 months follow-up post-RT. EBV viral capsid antigens (VCA) IgM and IgG, early antigen (EA) and nuclear antigen (EBNA) were all negative at the time of presentation. VCA IgM and IgG both became positive at 5 months and peaked at 9 months follow-up, however the EA and EBNA remained negative. EBV viral load as measured by polymerase chain reaction (PCR) was negative for the first 3 months post-RT but became positive at presentation, peaked at 6 months and started declining thereafter. Peripheral blood smear examination showed no absolute and atypical lymphocytosis. Cytomegalovirus PCR in the blood and throat culture for streptococcus were negative. There was no splenomegaly. He was managed conservatively with intravenous fluids, bed rest, antipyretics and reduction of immunosuppression. EBV serological markers have a limited role in the early diagnosis of EBV-IM following RT in prior seronegative children. Initial heterophile antibody test may also be negative, and hence a repeat test may be necessary. Once becoming positive, the VCA IgM may remain persistently elevated for prolonged duration. In addition to the suppressed cellular immunity secondary to immunosuppression, humoral response to viral infections is also delayed in transplant recipients, especially in the early transplant period. Hence, routine monitoring with PCR is superior to serology in diagnosing IM early and monitoring the EBV infection post-RT for timely evaluation and management.
PubMed: 32331303
DOI: 10.3390/medicines7040021 -
Vaccine May 2020Somatic mutations in tumors often generate neoproteins that contain MHC-I-binding neoepitopes. Little is known if and how efficient tumor-specific neoantigens activate...
Somatic mutations in tumors often generate neoproteins that contain MHC-I-binding neoepitopes. Little is known if and how efficient tumor-specific neoantigens activate CD8 T cells. Here, we asked whether a de novo generated neoepitope, encoded either within an otherwise conserved and ubiquitously expressed self-antigen or in a chimeric HBV core antigen expression platform, providing heterologous helper functions, induces CD8 T cells in C57Bl/6J mice by DNA immunization. For it, we chose an established D/Sp neoepitope generated in the murine Endophilin-B2/SH3GLB2 (EndoB2-Sp) protein by a single amino acid exchange. We showed that a single injection of EndoB2-Sp expression vectors efficiently primed dimer/pentamer, IFN-γ and cytolytic D/Sp-specific effector CD8 T cells in C57Bl/6J mice. Priming of D/Sp-specific CD8 T cells proceeded independent from CD4 T-cell help in MHC-II-deficient Aα mice. As compared to the homologous EndoB2-Sp vaccine, the selective expression of the D/Sp neoepitope in chimeric particle-forming and assembly-deficient HBV core antigens induced comparable frequencies D/Sp-specific CD8 T cells with the same cytolytic effector phenotype. The homologous EndoB2 carrier, but not the nine-residue neoepitope presented on chimeric HBV core particles, induced EndoB2-specific IgG antibody responses. The HBV core expression platform is thus an attractive option to selectively induce neoepitope-specific effector CD8 T cells by DNA vaccination. These novel findings have practical implications for the design of heterologous/self and heterologous/viral cancer vaccines that prime and/or activate neoepitope-specific CD8 T cells.
Topics: Adaptor Proteins, Signal Transducing; Animals; Antigens, Heterophile; Antigens, Viral; CD8-Positive T-Lymphocytes; DNA; Mice; Mice, Inbred C57BL; Neoplasms; Vaccination; Vaccines, DNA
PubMed: 32278524
DOI: 10.1016/j.vaccine.2020.04.003 -
Pathogens (Basel, Switzerland) Mar 2020Epstein-Barr virus (EBV) is the causative agent of many diseases including infectious mononucleosis (IM), and it is associated with different subtypes of lymphoma,... (Review)
Review
Epstein-Barr virus (EBV) is the causative agent of many diseases including infectious mononucleosis (IM), and it is associated with different subtypes of lymphoma, sarcoma and carcinoma such as Hodgkin's lymphoma, non-Hodgkin's lymphoma, nasopharyngeal carcinoma, and gastric carcinoma. With the advent of improved laboratory tests for EBV, a timelier and accurate diagnosis could be made to aid better prognosis and effective treatment. For histopathological lesions, the in situ hybridization (ISH) of EBV-encoded RNA (EBER) in biopsy tissues remains the gold standard for detecting EBV. Methods such as the heterophile antibody test, immunofluorescence assays, enzyme immunoassays, Western blot, and polymerase chain reaction (PCR) are also employed in the detection of EBV in different types of samples. The determination of EBV viral load using PCR, however, is gaining more prominence in the diagnosis of EBV-associated diseases. Given the challenge of false positive/negative results that are sometimes experienced during the detection of EBV, variability in results from different laboratories, and the impact of factors such as sample type and the immunological status of patients from whom samples are collected, the need to critically examine these present methods is invaluable. This review thus presents current advances in the detection of EBV, detailing the advantages and disadvantages of the various techniques. In addition, fundamental virological concepts are highlighted to enhance the greater understanding, the proper application, and the interpretation of EBV tests.
PubMed: 32197545
DOI: 10.3390/pathogens9030226 -
American Journal of Nephrology 2020Prolonged use of corticosteroids continues to be the mainstay in the management of most proteinuric glomerulopathies, but is limited by extensive side effects....
BACKGROUND
Prolonged use of corticosteroids continues to be the mainstay in the management of most proteinuric glomerulopathies, but is limited by extensive side effects. Alternative medications such as adrenocorticotropic hormone (ACTH) have been recently used to treat refractory glomerulopathies and have shown superior outcomes when compared with steroids. However, the clinical responsiveness to ACTH therapy varies considerably with a number of patients exhibiting de novo or acquired resistance. The underlying mechanism remains unknown.
METHODS
A patient with steroid-dependent focal segmental glomerulosclerosis (FSGS) developed severe steroid side effects impacting quality of life and was converted to repository porcine ACTH therapy. Immediate response in the form of remission of nephrotic syndrome was noted followed by relapse in 10 weeks. Suspecting the role of some ACTH-antagonizing factors, the patient's serum was examined.
RESULTS
Immunoblot-based antibody assay revealed high titers of de novo IgG antibodies in the patient's serum that were reactive to the porcine corticotropin with negligible cross-reactivity to human corticotropin. In vitro, in cultured B16 melanoma cells that express abundant melanocortin receptors, addition of the patient's serum substantially abrogated the porcine corticotropin triggered signaling activity of the melanocortinergic pathway, marked by phosphorylation of glycogen synthase kinase 3β, thus suggesting a mitigating effect on the biological functionality of porcine corticotropin.
CONCLUSION
ACTH is a useful alternative therapeutic modality for refractory proteinuric glomerulopathies like FSGS. However, as quintessential therapeutic biologics, natural ACTH, regardless of purity and origin, is inevitably antigenic and may cause the formation of neutralizing antibodies in some sensitive patients, followed by resistance to ACTH therapy. It is imperative to develop ACTH analogues with less immunogenicity for improving its responsiveness in patients with glomerular diseases.
Topics: Adrenocorticotropic Hormone; Adult; Animals; Antibodies, Heterophile; Antibodies, Neutralizing; Biopsy; Chronic Disease; Drug Resistance; Drug Substitution; Female; Glucocorticoids; Humans; Kidney; Nephrotic Syndrome; Recombinant Proteins; Recurrence; Remission Induction; Swine
PubMed: 32187600
DOI: 10.1159/000506854 -
JACC. Case Reports Mar 2020We present the case of a female patient who developed persistently elevated levels of cardiac troponin (cTn) after a previous episode of clinically presumed myocarditis....
We present the case of a female patient who developed persistently elevated levels of cardiac troponin (cTn) after a previous episode of clinically presumed myocarditis. Extensive investigation concluded that the presence of heterophile antibodies was causing false positive cTn elevation. ().
PubMed: 34317263
DOI: 10.1016/j.jaccas.2020.01.011 -
Vaccine Apr 2020Neisseria meningitidis is the causative agent of meningococcal meningitis and sepsis and remains a significant public health problem in many countries. Efforts to...
Neisseria meningitidis is the causative agent of meningococcal meningitis and sepsis and remains a significant public health problem in many countries. Efforts to develop a comprehensive vaccine against serogroup B meningococci have focused on the use of surface-exposed outer membrane proteins. Here we report the use of virus-like particles derived from the core protein of Hepatitis B Virus, HBc, to incorporate antigen domains derived from Factor H binding protein (FHbp) and the adhesin NadA. The extracellular domain of NadA was inserted into the major immunodominant region of HBc, and the C-terminal domain of FHbp at the C-terminus (CFHbp), creating a single polypeptide chain 3.7-fold larger than native HBc. Remarkably, cryoelectron microscopy revealed that the construct formed assemblies that were able to incorporate both antigens with minimal structural changes to native HBc. Electron density was weak for NadA and absent for CFHbp, partly attributable to domain flexibility. Following immunization of mice, three HBc fusions (CFHbp or NadA alone, NadA + CFHbp) were able to induce production of IgG1, IgG2a and IgG2b antibodies reactive against their respective antigens at dilutions in excess of 1:18,000. However, only HBc fusions containing NadA elicited the production of antibodies with serum bactericidal activity. It is hypothesized that this improved immune response is attributable to the adoption of a more native-like folding of crucial conformational epitopes of NadA within the chimeric VLP. This work demonstrates that HBc can incorporate insertions of large antigen domains but that maintenance of their three-dimensional structure is likely to be critical in obtaining a protective response.
Topics: Animals; Antigens, Bacterial; Antigens, Heterophile; Bacterial Proteins; Cryoelectron Microscopy; Hepatitis B; Hepatitis B Core Antigens; Hepatitis B virus; Meningococcal Vaccines; Mice; Neisseria meningitidis; Neisseria meningitidis, Serogroup B; Viral Core Proteins
PubMed: 32178907
DOI: 10.1016/j.vaccine.2020.03.001 -
Annales de Biologie Clinique Feb 2020Identifying analytical interference is a challenge for the medical biologist in providing advice to the prescriber. Indeed, these analytical interferences often have...
Identifying analytical interference is a challenge for the medical biologist in providing advice to the prescriber. Indeed, these analytical interferences often have deleterious consequences on the care of patients. Understanding their mechanisms and mastering corrective procedures is essential to limit these management errors. Faced with the many questions from clinicians in current practice, we propose an algorithm for managing a sample when interference is suspected.
Topics: Algorithms; Antibodies, Heterophile; Artifacts; Clinical Laboratory Techniques; Decision Trees; False Positive Reactions; Health Knowledge, Attitudes, Practice; Humans; Immunoassay; Immunologic Tests; Practice Guidelines as Topic; Scientific Experimental Error
PubMed: 32108582
DOI: 10.1684/abc.2020.1514 -
The Kaohsiung Journal of Medical... Jun 2020Adipose tissue-derived mesenchymal stem cells (ADSCs) are multipotent cells that can differentiate into various cell types. This study aimed to investigate the effect of...
Adipose tissue-derived mesenchymal stem cells (ADSCs) are multipotent cells that can differentiate into various cell types. This study aimed to investigate the effect of ghrelin on the neural differentiation of rat ADSCs and underlying molecular mechanisms. Rat ADSCs were isolated and third-passage ADSCs were used in this study. The isolated ADSCs were characterized by flow cytometry analysis for MSCs' surface expression markers as evidenced by positive for CD90, CD44, and CD29 and negative for CD34, CD45, and CD11b/2f/c. The multilineage differentiation of ADSCs was confirmed by adipogenic, osteogenic, and neural differentiation. After induction of neurogenesis, the differentiated cells were identified by development of neuron-like morphology and expression of neural markers including glial fibrillary acidic protein, Nestin, MAP2, and β-Tubulin III using immunofluorescence and western blot. Ghrelin concentration dependently elevated the proportion of neural-like cells and branching dendrites, as well as upregulated the expression of neural markers. Further, the expression of nuclear β-catenin, p-GSK-3β, p-AKT, and p-mTOR was increased by ghrelin, indicating an activation of β-catenin and AKT/mTOR signaling after the ghrelin treatment. Importantly, inhibition of β-catenin or AKT/mTOR signaling suppressed ghrelin-induced neurogenesis. Therefore, we demonstrate that ghrelin promotes neural differentiation of ADSCs through the activation of β-catenin and AKT/mTOR signaling pathways.
Topics: Adipocytes; Adipose Tissue; Animals; Antibodies, Heterophile; Cell Differentiation; Gene Expression Regulation; Ghrelin; Glial Fibrillary Acidic Protein; Glycogen Synthase Kinase 3 beta; Heterocyclic Compounds, 3-Ring; Hyaluronan Receptors; Integrin beta1; Male; Mesenchymal Stem Cells; Microtubule-Associated Proteins; Nestin; Neurons; Primary Cell Culture; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Signal Transduction; TOR Serine-Threonine Kinases; Thy-1 Antigens; Tubulin; beta Catenin
PubMed: 32003536
DOI: 10.1002/kjm2.12188 -
Scientific Reports Dec 2019Pelvic recurrence of colorectal cancer is a crucial problem because radical surgery can lead to excessive invasion. Novel therapeutic strategies are required instead of...
Pelvic recurrence of colorectal cancer is a crucial problem because radical surgery can lead to excessive invasion. Novel therapeutic strategies are required instead of surgery. However, there are few suitable models because of the difficulty in transplanting and observing tumors in the pelvis. We have established an appropriate injection site suitable for the establishment of colorectal cancer pelvic recurrence that allows for the observation of tumor growth. DLD-1 cells stably expressing luciferase (DLD-1 clone#1-Luc) were inoculated into various points of female BALB/c nude mice and the engrafted cells were analyzed with an imaging system employing bioluminescent signals and computed tomography. Weekly analysis with the imaging system showed that a triangular area defined by the vagina, the anus, and the ischial spine was suitable for the engraftment of pelvic tumors. The imaging system was able to detect the engrafted tumor 7 days after the inoculation of cells. Weight loss was observed in our model, and overall survival was 21-42 days. Tumor involvement of adjacent organs was detected histopathologically, as is the case in the clinical situation. These findings suggest that this model is valid for evaluations of the therapeutic effects of novel treatments under development. It is hoped that this model will be used in preclinical research.
Topics: Animals; Antibodies, Heterophile; Cell Line, Tumor; Colorectal Neoplasms; Female; Heterografts; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Recurrence, Local; Neoplasm Transplantation; Neoplasms, Experimental; Pelvic Neoplasms
PubMed: 31873140
DOI: 10.1038/s41598-019-56152-0 -
Xenotransplantation Mar 2020Engineering of α-Galactosyltransferase gene-knockout pigs circumvented hyperacute rejection of pig organs after xenotransplantation in non-human primates. Overcoming...
BACKGROUND
Engineering of α-Galactosyltransferase gene-knockout pigs circumvented hyperacute rejection of pig organs after xenotransplantation in non-human primates. Overcoming this hurdle revealed the importance of non-α-Gal carbohydrate antigens in the immunobiology of acute humoral xenograft rejection.
METHODS
This study analyzed serum from seven naïve cynomolgus monkeys (blood type O/B/AB = 3/2/2) for the intensity of natural IgM and IgG signals using carbohydrate antigen microarray, which included historically reported α-Gal and non-α-Gal carbohydrate antigens with various modifications.
RESULTS
The median (range) of IgM and IgG signals were 12.71 (7.23-16.38) and 9.05 (7.23-15.90), respectively. The highest IgM and IgG signals with narrowest distribution were from mono- and disaccharides, followed by modified structures. Natural anti-α-Gal antibody signals were medium to high in IgM (11.2-15.9) and medium in IgG (8.5-11.6) spectra, and was highest with Lac core structure (Galα1-3Galβ1-4Glc, iGb3) and lowest with LacNAc core structure (Galα1-3Galβ1-4GlcNAc). Similar signal intensities (up to 15.8 in IgM and up to 11.8 in IgG) were observed for historically detected natural non-α-Gal antigens, which included Tn antigen, T antigen, GM2 glycolipid, and Sd antigen. The hierarchical clustering analysis revealed the presence of clusters of anti-A antibodies and was capable of distinguishing between the blood group B and AB non-human primates.
CONCLUSIONS
The results presented here provide the most comprehensive evaluation of natural antibodies present in cynomolgus monkeys.
Topics: Animals; Antibodies; Antigens, Heterophile; Disaccharides; Galactosyltransferases; Graft Rejection; Heterografts; Macaca fascicularis; Primates; Transplantation, Heterologous
PubMed: 31762117
DOI: 10.1111/xen.12567