bluuebunny/crossref_metadata_2025_split huggingface dataset:
Loss of EBV-Specific CD4+T Cells during Progression to EBV-Related AIDS Non-Hodgkin Lymphoma: Restoration by Highly Active Antiretroviral Therapy (HAART).
Authors: Piriou Erwan R. , Jansen Christine , van Dort Karel , De Cuyper Iris , Nanlohy Nening M. , Lange Joep M. , Miedema Frank , Van Oers Marinus H.J. , van Baarle Debbie 
Published: October 2019

Abstract
Objective: EBV-specific CD8+ T cells have been extensively studied in various settings, and appear to play a major role in the control of EBV-related malignancies. In contrast, it is still unclear whether EBV-specific CD4+ T cells play a role in vivo. To study this question, an assay was developed to measure the CD4+ T-cell response towards two EBV antigens, in both healthy (n=14) and HIV-infected subjects (n=23). In addition, both HAART-treated (n=12) and untreated HIV+ individuals (n=14) - including progressors to EBV-related lymphoma - were studied longitudinally.
Methods: EBV-specific CD4+ T cells were stimulated with peptide pools from latent protein EBNA1 and lytic protein BZLF1, and detected by measurement of IFNg-production.
Results: After direct ex vivo stimulation, EBNA1 or BZLF1-specific IFNg- (and/or IL2) producing CD4+ T cell numbers were low, and measurable in less than half of the subjects studied (either HIV- and HIV+). Therefore, PBMC were cultured for 12 days in the presence of peptides and IL2 (from day 3), and then restimulated with peptides, allowing specific and reproducible expansion of EBV-specific CD4+ T cells, independent of HLA type and ex vivo antigen processing. Interestingly, numbers of EBV-specific CD4+ T cells inversely correlated with EBV viral load, implying an important role for EBV-specific CD4+ T cells in the control of EBV in vivo. Untreated HIV-infected individuals had a lower CD4+ T cell response to EBNA1 and BZLF1 as compared to healthy EBV carriers and HAART-treated HIV+ subjects. In longitudinal samples, EBNA1-specific, but not BZLF1-specific T-cell numbers increased after HAART, while EBV load was not affected by treatment. In all the progressors to EBV-related lymphoma, EBV-specific CD4+ T cells were lost at least 24 months before lymphoma diagnosis.
Conclusions: Both cross-sectional and longitudinal data suggest an important role for EBV-specific CD4+ T cells in the control of EBV-related malignancies. Furthermore, it seems that HAART treatment leads to recovery of EBNA1-specific, but not BZLF1-specific CD4+ T-cell responses, implying changes in the latency pattern of EBV, despite an unaltered cell-associated EBV DNA load. Thus, early HAART treatment might prevent loss of specific CD4+ T-cell help and progression to NHL.
A Novel Human CD34(+) Subset That Constitutively Expresses the High Affinity Interleukin-2 Receptor Traffics to Lymph Nodes and Differentiates into CD56Bright Natural Killer Cells.
Authors: Freud Aharon G. , Becknell Brian , Roychowdhury Sameek , Mao Hsiaoyin C. , Ferketich Amy K. , Nuovo Gerard J. , Hughes Tiffany L. , Marburger Trent B. , Sung John , Baiocchi Robert A. , Guimond Martin , Caligiuri Michael A. 
Published: October 2019

Abstract
In adult humans, T cells differentiate in the thymus and B cells develop in the bone marrow, but the site(s) of natural killer (NK) cell differentiation are unclear. Here we describe, for the first time, a unique CD34(+) population found in human lymph nodes (LN) that differentiates into NK cells. CD56bright NK cells represent <10% of NK cells in peripheral blood (PB) yet predominate in LN where they can compete for endogenous T cell-derived IL-2 during immune activation due to their unique expression of functional high affinity (HA) interleukin (IL)-2 receptors (IL-2R). We hypothesized that a subset of CD34(+) hematopoietic precursor cells (HPC) might also express functional HA IL-2R and potentially differentiate into CD56bright NK cells via activation with low dose IL-2. We first identified a novel human CD34dimCD45RA(+) HPC in PB with constitutive expression of the HA IL-2R. When cultured in picomolar concentrations of IL-2 that selectively saturate the HA IL-2R, these cells give rise to CD56bright NK cells, and this effect is blocked when IL-2 cannot bind to its HA receptor. This unique CD34(+) population expresses IL-2Rα, CD2, CD7, c-kit, L-selectin, and NKR-P1A, all of which are also expressed by CD56bright NK cells. Unique among total PB CD34(+) cells, this novel population displays high integrin α4β7 expression. This attribute, in addition to its high L-selectin expression, suggested that these cells may traffic to LN where their progeny, CD56bright NK cells, represent the major NK subset. Indeed we found a distinct CD34dimCD45RA(+)α4β7bright population that resides in the T cell rich regions of human LN, and when stimulated in vitro with 10 pM IL-2, this cell gives rise to CD56bright NK cells. This novel population represents only ~6% of all PB CD34(+) HPC yet is the major if not exclusive CD34(+) subset in LN. While murine studies strongly support the notion that most if not all NK cells require IL-15 for their development, these new human data suggest a model for development of a minor human NK subset, the CD56bright NK cells, whereby CD34dimCD45RA(+)α4β7bright HPC constitutively expressing the HA IL-2R traffic to peripheral LN where endogenous T cell-derived IL-2 can drive CD56bright NK cell differentiation in vivo.
Cytomegalovirus pp65 - Recombinant Protein: A New Antigen for Efficient Restimulation of CD4+ and CD8+ pp65-Specific T Lymphocytes.
Authors: Richter Anne , Marschall Patricia , Mohn Marie , Odenthal Uwe , Gösling Silke , Skopnik Manuel , Nölle Volker , Assenmacher Mario 
Published: October 2019

Abstract
Short-term restimulation assays combined with the analysis of effector function, in particular the detection of cytokine production, are useful tools for the analysis and isolation of antigen-specific T cells. Until now, restimulations with soluble protein antigens failed to efficiently reactivate CD8+ T cells. We have developed a recombinant protein of the immunodominant cytomegalovirus (CMV) matrix protein pp65 for in vitro restimulation of pp65-specific CD4+ as well as CD8+ T cells. The efficiency of the CMV pp65 - Recombinant Protein to reactivate pp65-experienced CD4+ and CD8+ T cells and the specificity of the restimulated T cells were analysed.
PBMC from CMV seropositive donors were restimulated with CMV pp65 - Recombinant Protein or a complete pool of overlapping pp65 peptides. Afterwards T cells were analysed for intracellular IFN-γ production by flow cytometry. Interestingly, we observed that stimulation with CMV pp65 - Recombinant Protein results in IFN-γ production in CD4+ as well as CD8+ T cells with frequencies comparable to that using the peptide pool as antigen (n=17). In contrast, upon stimulation of PBMC from CMV seronegative donors with CMV pp65 - Recombinant Protein neither IFN-γ nor TNF-α were detectable in T cells (n=6).
Furthermore, we tested the specificity of CMV pp65 - Recombinant Protein-reactive CD4+ and CD8+ T cells. Therefore, IFN-γ-producing T cells were magnetically isolated after short-term stimulation with pp65 using the IFN-γ cytokine secretion assay and expanded for 7 days. Subsequently, the isolated and expanded CD4+ and CD8+ T cells were restimulated with pp65 peptide pool. More than 80 % of the CD4+ and CD8+ T cells produced IFN-γ and more than 80 % of the CD8+ T cells were positively stained with MHC class I/pp65 tetramers.
These results demonstrate that CMV pp65 - Recombinant Protein efficiently and specifically reactivates pp65-experienced CD4+ as well as CD8+ T cells. Therefore, CMV pp65 - Recombinant Protein is a useful antigen for the detection and isolation of pp65-experienced CD4+ and CD8+ effector/memory T cells.
Dependence of Vector Dose and Age of Mice in the Induction of Immune Response Against Factor VIII Following Liver-Directed Nonviral Gene Transfer.
Authors: Ye Peiqing , Miao Carol H. 
Published: October 2019

Abstract
Formation of inhibitory antibodies to transgene product may limit the success of gene therapy especially for the treatment of hemophilia A. The risk of forming inhibitory antibodies against factor VIII depends on multiple factors. Previously we have shown that following naked gene transfer of fifty micrograms of a liver-specific, high-expressing factor VIII plasmid, pBS-HCRHPI-FVIIIA into hemophilia A mice (at least 60 days old), a robust humoral response was induced two weeks post plasmid injection despite of initial high-level gene expression of factor VIII (Ye et al. (2004) Mol. Ther. 10, 117–126). This response completely inhibited the activity of circulating factor VIII although factor VIII was persistently expressed in the liver. In this study, the cytokine production was characterized in human factor VIII-activated T cells from plasmid-treated and untreated hemophilic A mice, consistent with a response predominantly mediated by Th2-induced signals. Injection of plasmid DNA into 4 groups of hemophilia A mice (n=5, 60 days old) with 4 different doses (0.4, 2, 10, & 50 microgram per animal) resulted in vector dose-dependent expression of factor VIII. In addition, the two groups of mice with lower doses of plasmid DNA (0.4 & 2 microgram per animal) did not elicit any antibody response against factor VIII, whereas the two groups of mice with higher doses of plasmid DNA (10 & 50 microgram per animal) induced inhibitory antibody formation. Nevertheless, when the two groups of animals (n=4) with lower doses were treated with second injection of fifty microgram of factor VIII plasmid 180 days post plasmid delivery, all mice developed inhibitors suggesting no immune tolerance was induced by first injection of plasmids. Furthermore, fifty micrograms of factor VIII plasmids were injected into 4 groups of hemophilia A mice (n=5) of 4 different age groups (36, 48, 60 & 72 days). It was found that none of the mice with age 36 days at the time of plasmid injection developed inhibitors, 1/5 mice with age 48 days developed inhibitors, whereas the two groups of mice with age 60 & 72 days all developed high-titer inhibitors. These results indicate that induction of anti-factor VIII antibody following gene therapy is strongly dependent upon the vector dose and age of the animals, which has important implication for developing immunomodulation or other strategies to avoid/eliminate antibody responses.
Isolation of Human CD34- Cells with High Aldehyde Dehydrogenase Activity Reveals a Novel Population with Hematopoietic Repopulating Potential.
Authors: Hess David A. , Herrbrich Phillip E. , Wirthlin Louisa , Craft Timothy P. , Nolta Jan A. 
Published: October 2019

Abstract
The successful development of stem cell-based therapies requires a thorough understanding of human hematopoietic stem cell (HSC) populations. Human CD34− cells engraft NOD/SCID mice with low efficiency by intravenous (IV) transplant. However, intra-femoral injection into immune deficient mice has identified potent human repopulating cells from CD34+ and CD34− subfractions. We recently described a novel strategy to purify reconstituting HSC from human umbilical cord blood (UCB) by lineage depletion (Lin−) followed by selection of cells with high aldehyde dehydrogenase (ALDH) activity. Hematopoietic progenitor function and in vivo reconstituting ability were exclusively maintained within the ALDHhiLin− population, which demonstrated variable expression of CD34. Here, we compared the repopulating ability of purified CD34+ALDHhiLin− and CD34−ALDHhiLin− populations to traditionally isolated CD34+Lin− and CD34−Lin− cells. Sorting of Lin− cells from human UCB isolated CD34−ALDHhi and CD34+ALDHhi cells (>96% purity) at an overall frequency of 4.4±1.3% or 29.1±3.5%, respectively. In contrast to CD34−Lin− cells, ALDHhiCD34−Lin− cells demonstrated robust clonogenic progenitor function in vitro (1 CFU in 9 cells, n=3), and total colony production was further increased in ALDHhiCD34+Lin− cells (1 CFU in 4.5 cells, n=4) (p<0.05). Human hematopoietic repopulation was consistently observed in the bone marrow (17.2±4.2%), spleen (0.8±0.2%), and peripheral blood (0.7±0.3%) of NOD/SCID β2M null mice 6–8 weeks after IV transplant with 103–104 purified ALDHhiCD34+Lin− cells (n=14). Similarly, intra-femoral injection (IF) of ALDHhiCD34+Lin− cells resulted in robust human repopulation (n=5). IV injection of equivalent doses of either ALDHhiCD34+Lin− or CD34+Lin− cells showed similar levels and frequencies of human hematopoietic engraftment. Repopulating ALDHhiCD34+Lin− cells also differentiated into cells expressing markers for mature myeloid (CD33, CD14), B-lymphoid (CD19, CD20) cells and primitive repopulating cells (CD34+CD38−) at similar frequencies as CD34+Lin− cells (n=5). IV injection of 2x104–1x105 ALDHhiCD34−Lin− cells engrafted at 0.2–0.3% in the BM of 3 of 4 NOD/SCID β2M null mice, whereas IV injection of up to 4x105 CD34−Lin− cells produced no detectable human engraftment (n=6). IF-injected ALDHhiCD34−Lin− cells engrafted the injected bone in 2 of 3 NOD/SCID mice at low levels and did not efficiently migrate to the non-injected femur or tibiae. In summary, the human UCB ALDHhiLin− population includes both CD34+ and CD34− cells capable of bone marrow homing and hematopoietic reconstitution. Therefore, isolation of CD34− cells based on high ALDH activity may reveal a novel population of hematopoietic stem and progenitor cells.
The Role of CBFβ in T Cell Development.
Authors: Zhao Ling , Cannons Jennifer L. , Castilla Lucio H. , Schwartzberg Pamela L. , Liu Pu Paul 
Published: October 2019

Abstract
Core binding factor β (Cbfβ) is a transcription factor that heterodimerizes with Runx (Cbfα) family members, thereby stabilizing the interaction between the Runx proteins and DNA. Genetically manipulated mouse models of Runx and Cbfb genes have demonstrated their critical functions in hematopoiesis (Runx1, Runx3 and Cbfb), bone formation (Runx2, Cbfb), proliferation of gastrointestinal epithelia (Runx3) and differentiation of dorsal root ganglion cells (Runx3). Studies on T cell development showed that Runx1 and Runx3 repress CD4 expression at different stages of development. In addition, Runx 1 and Runx 3 are required for CD8 T cell development during thymopoiesis. No defects were found when Runx2 was inactivated, even though it is expressed throughout T cell development.
We have previously generated a knock-in mouse model expressing the Cbfb-MYH11 fusion gene (which is created by inv(16)(p13; q22) in human AML M4Eo). Heterozygous knock-in mice had a phenotype identical to that of the Cbfb and Runx1 null mice (embryonic lethality), suggesting that the fusion gene Cbfb-MYH11 functions in a dominant-negative manner. In order to study the function of Cbfb gene in T cell development, we used a mouse line with floxed exons 5 and 6 of Cbfb inserted 5′ to the Cbfb-MYH11 fusion cassette, which produced pseudo-normal mice (loxKI). By crossing the loxKI mice with mice expressing the Cre gene under the control of the T cell-specific Lck promoter (LckCre), we generated LckCre-loxKI double positive mice, in which the floxed exon 5 and 6 were deleted and Cbfb-MYH11 re-expressed only in the thymus when Lck started to express. The LckCre-loxKI mice were viable. However, their thymic development was severely impaired: The size of the thymuses in the mutant mice was about half the normal size, and the total number of thymocytes in the mutant mice was 10–20-fold reduced. FACS analysis of thymocytes from 4 to 12 week old mice showed a developmental blockade at the CD4/CD8-double negative (DN) stage, which was characterized by lower percentage of double positive cells and higher percentage of double negative cells. In addition, the CD4: CD8 ratio was altered. Furthermore, the mature T cell population size in the spleen of the mutant mice was lower than that of the control mice. Our preliminary data suggested that Cbfb plays an important role in T cell development. The mechanism through which Cbfb affects the T cell development is currently under investigation. It is likely that the phenotype reflects the combined effect of missing all three Runx genes, since the phenotype described here is more severe than either Runx1 or Runx3 null alone.
EBV Transformation of Tonsil Germinal Centre B Cells Carrying Functionally Inactivated IgV Gene.
Authors: Chaganti Sridhar , Pastor Noelia Begue , Drayson Mark T. , Bell Andy I. , Rickinson Alan B. 
Published: October 2019

Abstract
Somatic hypermutation of immunoglobulin (Ig) gene sequences in the germinal centres of lymphoid tissues is necessary for affinity maturation of B cell responses to antigen challenge. This process generates a few clones with improved affinity that are selected into B cell memory and many clones with other non favourable Ig mutations, including some cells with functionally inactivated Ig gene that normally die by apoptosis. It is postulated that infection with Epstein-Barr virus (EBV), a B lymphotropic agent linked to several types of B cell lymphoma, can rescue germinal centre cells with unfavourable mutations. This creates a pool of infected cells at greater risk of developing into lymphomas. In the present work, CD38+ germinal centre B cells were separated from tonsil by negative selection for IgD and CD39. Peripheral blood naïve and memory B cell subpopulations were FACS sorted as IgD+, CD27− and IgD−, CD27+ fractions respectively. These cells were infected with EBV (B95.8 strain) in vitro and seeded at limiting dilutions onto fibroblast feeders. EBV transformed lymphoblastoid cell lines (LCLs) from such cultures were analysed for surface Ig phenotype. Naïve B cell transformants were consistently IgM+, IgD+. Memory B cell transformants were IgM+ in some cases but more frequently IgG+ or IgA+. Germinal centre transformants showed the same spectrum of surface Ig phenotypes as memory cell transformants but in addition we identified six germinal centre derived LCLs which were consistently surface Ig negative. Sequencing from these lines confirmed that in at least three cases EBV had rescued cells with functionally inactivated Ig heavy chain gene.
Fc-Gamma Receptor IIIa and Interferon-Gamma SNPs Do Not Predict Responsiveness of Follicular Lymphoma to Galiximab (Anti-CD80 Antibody).
Authors: Czuczman Myron , Leigh Bryan R. , Witzig Thomas E. , Vose Julie M. , Younes Anas , Alkuzweny Baha , Larocca Anne , Cao Xianjun , Thall Aron 
Published: October 2019

Abstract
CD80 is an immune costimulatory molecule expressed on the cell surface of follicular and other lymphomas. Galiximab, a macaque-human chimeric anti-CD80 monoclonal antibody, has been shown to have antitumor activity in patients with relapsed or refractory, follicular lymphoma. Preclinical work suggested antibody-dependent cellular cytotoxicity (ADCC) as a mechanism for galiximab-induced cell lysis. Single-nucleotide polymorphisms (SNPs) for high-affinity Fc gamma receptor IIIa and high interferon-gamma production have been associated with increased ADCC activity. For this report, genomic DNA from peripheral blood of clinical study patients was analyzed for Fc gamma receptor IIIa and interferon-gamma gene SNPs after PCR amplification. In addition, the frequency of interferon-gamma secreting cells in peripheral blood samples was evaluated by ELISPOT. SNP and ELISPOT results were then evaluated for correlation with clinical response (CR or PR) to galiximab and reduction in tumor burden (SPD of indicator lesions). Of 35 follicular lymphoma patients evaluable for response to galiximab, 2 CRs and 1 PR were observed; time to best response was delayed (Months 3, 9, and 12). Of 34 patients with Fc gamma receptor IIIa SNP results, 6 were homozygous for the high-affinity receptor. Of 33 pts with interferon-gamma SNP results, 4 were homozygous for the high-producing allele. None of the 3 responders were homozygous for high-affinity Fc gamma receptor IIIa or high interferon-gamma production, and the degree of tumor burden reduction was smaller in these homozygotes than in the others. In addition, pretreatment interferon-gamma ELISPOT data did not predict clinical response to galiximab or tumor burden reduction. In summary, high-affinity Fc gamma receptor IIIa and high interferon-gamma production do not predict clinical responsiveness of follicular NHL to galiximab, suggesting that ADCC may not be a primary mechanism of action for this antibody. Ongoing studies are evaluating other potential mechanisms including the immunomodulatory effects of blocking CD80.
FDG PET Scan Alone Better Predicts Progression Free Survival at 2 Years Compared to CT Imaging in Aggressive Histology Non-Hodgkin’s Lymphoma Following Initial Anthracycline-Based Chemotherapy.
Authors: Wiseman Gregory A. , Juweid Malik E. , Rohren Eric M. , Wooldridge James E. , Graham Michael M. 
Published: October 2019

Abstract
Background: CT imaging has routinely been used for assessing therapy response in most malignancies including Non-Hodgkins Lymphoma (NHL). The presence of residual tumor is generally categorized using the International Workshop Criteria from CT imaging and bone marrow biopsies for assessing response after treatment. CT imaging has limitations in assessment of response to therapy in NHL with false positive results due to residual masses having viable tumor cells in less than 20% and the remainder being fibrosis or necrosis. In addition false negative CT results are seen due to viable tumor cells in nodes measuring less than 1.5 cm in size. F-18 FDG PET scans provide metabolic imaging of viable tumor cells due to uptake and retention of F-18 fluorodeoxyglucose preferentially in malignant cells.
Method: Forty-eight patients with aggressive NHL having completed anthracycline-based chemotherapy had the post therapy FDG PET scans and CT scans reviewed by experienced readers blinded from the comparison scan and from the clinical history. PET scans were read as positive or negative for abnormal FDG consistent with residual viable tumor and the CT was read as positive or negative for nodes greater than 1.5 cm in diameter. Records were reviewed for tumor histology and evidence of tumor relapse with a median follow-up of 35 months.
Results: The FDG PET and CT imaging prediction of PFS at 2 years had positive predictive values of 67% and 38%, negative predictive values of 88% and 78%, and accuracy of 81% and 50% respectively. The sensitivity and specificity of the FDG PET scan was 71% and 82% for predicting disease progression within 2 years from beginning treatment.
Conclusion: FDG PET imaging was compared with CT imaging done after completing initial chemotherapy for aggressive NHL and demonstrated superior prediction of tumor response status at 2 years. These results indicate that FDG PET imaging should be combined with bone marrow biopsy for restaging aggressive NHL after completion of chemotherapy. The use of FDG PET is more accurate and should replace response assessment by CT imaging in most pateints with aggressive NHL following treatment.