scholarly journals An Animal Model That Mimics Human Herpesvirus 6B Pathogenesis

2019 ◽  
Vol 94 (6) ◽  
Author(s):  
Bochao Wang ◽  
Yasuyuki Saito ◽  
Mitsuhiro Nishimura ◽  
Zhenxiao Ren ◽  
Lidya Handayani Tjan ◽  
...  

ABSTRACT Human herpesvirus 6B (HHV-6B), a T-lymphotropic virus, infects almost exclusively humans. An animal model of HHV-6B has not been available. Here, we report the first animal model to mimic HHV-6B pathogenesis; the model is based on humanized mice in which human immune cells were engrafted and maintained. For HHV-6B replication, adequate human T-cell activation (which becomes susceptible to HHV-6B) is necessary in this murine model. Here, we found that an additional transfer of human mononuclear cells to humanized mice resulted in an explosive proliferation of human activated T cells, which could be representative of graft-versus-host disease (GVHD) because the primary transfer of human cells was not sufficient to increase the number and ratio of human T cells. Mice infected with HHV-6B became weak and/or died approximately 7 to 14 days later. Quantitative PCR analysis revealed that the spleen and lungs were the major sites of HHV-6B replication in this model, and this was corroborated by the detection of viral proteins in these organs. Histological analysis also revealed the presence of megakaryocytes, indicating HHV-6B infection. Multiplex analysis of cytokines/chemokines in sera from the infected mice showed secretions of human cytokines/chemokines as reported for both in vitro infection and clinical samples, indicating that the secreted cytokines could affect pathogenesis. This is the first animal model showing HHV-6B pathogenesis, and it will be useful for elucidating the pathogenicity of HHV-6B, which is related to GVHD and idiopathic pneumonia syndrome. IMPORTANCE Human herpesvirus 6B (HHV-6B) is a ubiquitous virus that establishes lifelong latent infection only in humans, and the infection can reactivate, with severe complications that cause major problems. A small-animal model of HHV-6B infection has thus been desired for research regarding the pathogenicity of HHV-6B and the development of antiviral agents. We generated humanized mice by transplantation with human hematopoietic stem cells, and here, we modified the model by providing an additional transfer of human mononuclear cells, providing the proper conditions for efficient HHV-6B infection. This is the first humanized mouse model to mimic HHV-6B pathogenesis, and it has great potential for research into the in vivo pathogenesis of HHV-6B.

Blood ◽  
2020 ◽  
Author(s):  
Jennifer A Ball ◽  
Andrew James Clear ◽  
James Aries ◽  
Sarah Charrot ◽  
Caroline Besley ◽  
...  

Gastrointestinal (GI) graft-versus-host disease (GvHD) is a major barrier in allogeneic hematopoietic stem-cell transplantation (AHST). The metabolite retinoic acid (RA) potentiates GI-GvHD in mice via alloreactive T-cells expressing the RA-receptor-alpha (RARα), but the role of RA-responsive cells in human GI-GvHD remains undefined. We therefore used conventional and novel sequential immunostaining and flow cytometry to scrutinize RA-responsive T-cells in tissues and blood of AHST patients and characterize the impact of RA on human T-cell alloresponses. Expression of RARα by human mononuclear cells was increased after RA exposure. RARαhi mononuclear cells were increased in GI-GvHD tissue, contained more cellular RA-binding proteins, localized with tissue damage and correlated with GvHD severity and mortality. Using a targeted candidate protein approach we predicted the phenotype of RA-responsive T-cells in the context of increased microenvironmental IL-23. Sequential immunostaining confirmed the presence of a population of RARahi CD8 T-cells with the predicted phenotype, co-expressing the effector T-cell transcription factor T-bet and the IL-23-specific receptor. These cells were increased in GI- but not skin-GvHD tissues and were also selectively expanded in GI-GvHD patient blood. Finally, functional approaches demonstrated RA predominantly increased alloreactive GI-tropic RARahi CD8 effector T-cells, including cells with the phenotype identified in vivo. IL-23-rich conditions potentiated this effect by selectively increasing b7 integrin expression on CD8 effector T-cells and reducing CD4 T-cells with a regulatory cell phenotype. In conclusion we have identified a population of RA-responsive effector T-cells with a distinctive phenotype which are selectively expanded in human GI-GvHD and represent a potential new therapeutic target.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ashton C. Trotman-Grant ◽  
Mahmood Mohtashami ◽  
Joshua De Sousa Casal ◽  
Elisa C. Martinez ◽  
Dylan Lee ◽  
...  

AbstractT cells are pivotal effectors of the immune system and can be harnessed as therapeutics for regenerative medicine and cancer immunotherapy. An unmet challenge in the field is the development of a clinically relevant system that is readily scalable to generate large numbers of T-lineage cells from hematopoietic stem/progenitor cells (HSPCs). Here, we report a stromal cell-free, microbead-based approach that supports the efficient in vitro development of both human progenitor T (proT) cells and T-lineage cells from CD34+cells sourced from cord blood, GCSF-mobilized peripheral blood, and pluripotent stem cells (PSCs). DL4-μbeads, along with lymphopoietic cytokines, induce an ordered sequence of differentiation from CD34+ cells to CD34+CD7+CD5+ proT cells to CD3+αβ T cells. Single-cell RNA sequencing of human PSC-derived proT cells reveals a transcriptional profile similar to the earliest thymocytes found in the embryonic and fetal thymus. Furthermore, the adoptive transfer of CD34+CD7+ proT cells into immunodeficient mice demonstrates efficient thymic engraftment and functional maturation of peripheral T cells. DL4-μbeads provide a simple and robust platform to both study human T cell development and facilitate the development of engineered T cell therapies from renewable sources.


2021 ◽  
Author(s):  
Emily Stephenson ◽  
◽  
Gary Reynolds ◽  
Rachel A. Botting ◽  
Fernando J. Calero-Nieto ◽  
...  

AbstractAnalysis of human blood immune cells provides insights into the coordinated response to viral infections such as severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19). We performed single-cell transcriptome, surface proteome and T and B lymphocyte antigen receptor analyses of over 780,000 peripheral blood mononuclear cells from a cross-sectional cohort of 130 patients with varying severities of COVID-19. We identified expansion of nonclassical monocytes expressing complement transcripts (CD16+C1QA/B/C+) that sequester platelets and were predicted to replenish the alveolar macrophage pool in COVID-19. Early, uncommitted CD34+ hematopoietic stem/progenitor cells were primed toward megakaryopoiesis, accompanied by expanded megakaryocyte-committed progenitors and increased platelet activation. Clonally expanded CD8+ T cells and an increased ratio of CD8+ effector T cells to effector memory T cells characterized severe disease, while circulating follicular helper T cells accompanied mild disease. We observed a relative loss of IgA2 in symptomatic disease despite an overall expansion of plasmablasts and plasma cells. Our study highlights the coordinated immune response that contributes to COVID-19 pathogenesis and reveals discrete cellular components that can be targeted for therapy.


Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1059
Author(s):  
Jinyeong Yu ◽  
Sanghyuk Choi ◽  
Aran Park ◽  
Jungbeom Do ◽  
Donghyun Nam ◽  
...  

Cancer cachexia is a multifactorial systemic inflammation disease caused by complex interactions between the tumor and host tissues via soluble factors. However, whether cancer cachexia affects the bone marrow, in particular the hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs), remains unclear. Here, we investigated the bone marrow and bone in a cancer cachexia animal model generated by transplanting Lewis lung carcinoma cells. The number of bone marrow mononuclear cells (BM-MNCs) started to significantly decrease in the cancer cachectic animal model prior to the discernable loss of muscle and fat. This decrease in BM-MNCs was associated with myeloid skewing in the circulation and the expansion of hematopoietic progenitors in the bone marrow. Bone loss occurred in the cancer cachexia animal model and accompanied the decrease in the bone marrow MSCs that play important roles in both supporting HSCs and maintaining bone homeostasis. Glucocorticoid signaling mediated the decrease in bone marrow MSCs in the cancer cachectic environment. The cancer cachexia environment also skewed the differentiation of the bone marrow MSCs toward adipogenic fate via JAK/STAT as well as glucocorticoid signaling. Our results suggest that the bone loss induced in cancer cachexia is associated with the depletion and the impaired differentiation capacity of the bone marrow MSCs.


Author(s):  
Adjimon G Lokossou ◽  
Caroline Toudic ◽  
Phuong Trang Nguyen ◽  
Xavier Elisseeff ◽  
Amandine Vargas ◽  
...  

Abstract Modulation of the activation status of immune cell populations during pregnancy depends on placental villous cytotrophoblast (VCT) cells and the syncytiotrophoblast (STB). Failure in the establishment of this immunoregulatory function leads to pregnancy complications. Our laboratory has been studying Syncytin-2 (Syn-2), an endogenous retroviral protein expressed in placenta and on the surface of placental exosomes. This protein plays an important role not only in STB formation through its fusogenic properties, but also through its immunosuppressive domain (ISD). Considering that Syn-2 expression is importantly reduced in preeclamptic placentas, we were interested in addressing its possible immunoregulatory effects on T cells. Activated Jurkat T cells and peripheral blood mononuclear cells (PBMCs) were treated with monomeric or dimerized version of a control or a Syn-2 ISD peptide. Change in phosphorylation levels of ERK1/2 MAP kinases was selectively noted in Jurkat cells treated with the dimerized ISD peptide. Upon incubation with the dimerized Syn-2 ISD peptide, significant reduction in Th1 cytokine production was further demonstrated by ELISA and Human Th1/Th2 Panel Multi-Analyte Flow Assay. To determine if exosome-associated Syn-2 could also be immunosuppressive placental exosomes were incubated with activated Jurkat and PBMCs. Quantification of Th1 cytokines in the supernatants revealed severe reduction in T cell activation. Interestingly, exosomes from Syn-2-silenced VCT incubated with PBMCs were less suppressive when compared with exosome derived from VCT transfected with control small interfering RNA (siRNA). Our results suggest that Syn-2 is an important immune regulator both locally and systemically, via its association with placental exosomes.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4640-4640
Author(s):  
Heng-Yi Liu ◽  
Nezia Rahman ◽  
Tzu-Ting Chiou ◽  
Satiro N. De Oliveira

Background: Chemotherapy-refractory or recurrent B-lineage leukemias and lymphomas yield less than 50% of chance of cure. Therapy with autologous T-cells expressing chimeric antigen receptors (CAR) have led to complete remissions, but the effector cells may not persist, limiting clinical efficacy. Our hypothesis is the modification of hematopoietic stem cells (HSC) with anti-CD19 CAR will lead to persistent generation of multilineage target-specific immune cells, enhancing graft-versus-cancer activity and leading to development of immunological memory. Design/Methods: We generated second-generation CD28- and 4-1BB-costimulated CD19-specific CAR constructs using third-generation lentiviral vectors for modification of human HSC for assessment in vivo in NSG mice engrafted neonatally with human CD34-positive cells. Cells were harvested from bone marrows, spleens, thymus and peripheral blood at different time points for evaluation by flow cytometry and ddPCR for vector copy numbers. Cohorts of mice received tumor challenge with subcutaneous injection of lymphoma cell lines. Results: Gene modification of HSC with CD19-specific CAR did not impair differentiation or proliferation in humanized mice, leading to CAR-expressing cell progeny in myeloid, NK and T-cells. Humanized NSG engrafted with CAR-modified HSC presented similar humanization rates to non-modified HSC, with multilineage CAR-expressing cells present in all tissues with stable levels up to 44 weeks post-transplant. No animals engrafted with CAR-modified HSC presented autoimmunity or inflammation. T-cell populations were identified at higher rates in humanized mice with CAR-modified HSC in comparison to mice engrafted with non-modified HSC. CAR-modified HSC led to development of T-cell effector memory and T-cell central memory phenotypes, confirming the development of long-lasting phenotypes due to directed antigen specificity. Mice engrafted with CAR-modified HSC successfully presented tumor growth inhibition and survival advantage at tumor challenge with lymphoma cell lines, with no difference between both constructs (62.5% survival for CD28-costimulated CAR and 66.6% for 41BB-costimulated CAR). In mice sacrificed due to tumor development, survival post-tumor injection was directly correlated with tumor infiltration by CAR T-cells. Conclusions: CAR modification of human HSC for cancer immunotherapy is feasible and continuously generates CAR-bearing cells in multiple lineages of immune cells. Targeting of different malignancies can be achieved by adjusting target specificity, and this approach can augment the anti-lymphoma activity in autologous HSC recipients. It bears decreased morbidity and mortality and offers alternative therapeutic approach for patients with no available sources for allogeneic transplantation, benefiting ethnic minorities. Disclosures De Oliveira: National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London: Research Funding; NIAID, NHI: Research Funding; Medical Research Council: Research Funding; CIRM: Research Funding; National Gene Vector Repository: Research Funding.


Blood ◽  
2014 ◽  
Vol 123 (3) ◽  
pp. 346-355 ◽  
Author(s):  
Kenta Tezuka ◽  
Runze Xun ◽  
Mami Tei ◽  
Takaharu Ueno ◽  
Masakazu Tanaka ◽  
...  

Key Points Humanized mice, IBMI-huNOG, were generated by intra–bone marrow injection of human CD133+ hematopoietic stem cells. HTLV-1–infected IBMI-huNOG mice recapitulated distinct ATL-like symptoms as well as HTLV-1–specific adaptive immune responses.


2005 ◽  
Vol 12 (7) ◽  
pp. 861-866 ◽  
Author(s):  
Elke Lainka ◽  
Michael S. Hershfield ◽  
Ines Santisteban ◽  
Pawan Bali ◽  
Annette Seibt ◽  
...  

ABSTRACT We describe the effects of polyethylene glycol-conjugated adenosine deaminase (ADA) replacement therapy on lymphocyte counts, activation, apoptosis, proliferation, and cytokine secretion in a 14-month-old girl with “delayed-onset” ADA deficiency and marked immunodysregulation. Pretreatment lymphopenia affected T cells (CD4, 150/μl; CD8, 459/μl), B cells (16/μl), and NK cells (55/μl). T cells were uniformly activated and largely apoptotic (CD4, 59%; CD8, 82%); and T-cell-dependent cytokine levels in plasma were elevated, including the levels of interleukin 2 (IL-2; 26 pg/ml), IL-4 (81 pg/ml), IL-5 (46 pg/ml), gamma interferon (1,430 pg/ml), tumor necrosis factor alpha (210 pg/ml), and IL-10 (168 pg/ml). Mitogen-stimulated peripheral blood mononuclear cells show reduced IL-2 secretion and proliferation. During the first 5 months of therapy there was clinical improvement and partial immune reconstitution, with nearly normal lymphocyte subset numbers, reduced T-cell activation and CD4-cell apoptosis, and decreased plasma cytokine levels. In parallel, IL-2 secretion and the lymphocyte mitogenic response improved. Between 4 and 7 months, immunoglobulin G antibodies to bovine ADA developed and resulted in the complete reversal of immune recovery.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Peter A. Szabo ◽  
Hanna Mendes Levitin ◽  
Michelle Miron ◽  
Mark E. Snyder ◽  
Takashi Senda ◽  
...  

Abstract Human T cells coordinate adaptive immunity in diverse anatomic compartments through production of cytokines and effector molecules, but it is unclear how tissue site influences T cell persistence and function. Here, we use single cell RNA-sequencing (scRNA-seq) to define the heterogeneity of human T cells isolated from lungs, lymph nodes, bone marrow and blood, and their functional responses following stimulation. Through analysis of >50,000 resting and activated T cells, we reveal tissue T cell signatures in mucosal and lymphoid sites, and lineage-specific activation states across all sites including distinct effector states for CD8+ T cells and an interferon-response state for CD4+ T cells. Comparing scRNA-seq profiles of tumor-associated T cells to our dataset reveals predominant activated CD8+ compared to CD4+ T cell states within multiple tumor types. Our results therefore establish a high dimensional reference map of human T cell activation in health for analyzing T cells in disease.


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