scholarly journals Chimerism, the Microenvironment and Control of Leukemia

2021 ◽  
Vol 12 ◽  
Author(s):  
H. Joachim Deeg
Keyword(s):  
Host Cells ◽  
Cell Manipulation ◽  
Malignant Cells ◽  
Host Interactions ◽  
Donor Cells ◽  
Metabolic Products ◽  
Conditioning Regimens ◽  
Modifying Effect ◽  
And Control ◽  
Remarkable Progress

Transplantation of allogeneic hematopoietic cells faces two barriers: failure of engraftment due to a host versus graft reaction, and the attack of donor cells against the patient, the graft versus host (GVH) reaction. This reaction may lead to GVH disease (GVHD), but in patients transplanted due to leukemia or other malignant disorders, this may also convey the benefit of a graft versus leukemia (GVL) effect. The interplay of transplant conditioning with donor and host cells and the environment in the patient is complex. The microbiome, particularly in the intestinal tract, profoundly affects these interactions, directly and via soluble mediators, which also reach other host organs. The microenvironment is further altered by the modifying effect of malignant cells on marrow niches, favoring the propagation of the malignant cells. The development of stable mixed donor/host chimerism has the potential of GVHD prevention without necessarily increasing the risk of relapse. There has been remarkable progress with novel conditioning regimens and selective T-cell manipulation aimed at securing engraftment while preventing GVHD without ablating the GVL effect. Interventions to alter the microenvironment and change the composition of the microbiome and its metabolic products may modify graft/host interactions, thereby further reducing GVHD, while enhancing the GVL effect. The result should be improved transplant outcome.

scholarly journals Bendamustine Conditioning Alters Host Dendritic Cell Composition and Function

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5670-5670
Author(s):  
Megan Stanley Molina ◽  
Jessica Stokes ◽  
Emely Hoffman ◽  
Emmanuel Katsanis
Keyword(s):  
Flow Cytometry ◽  
Total Body Irradiation ◽  
Conflicts Of Interest ◽  
Host Cells ◽  
Differential Effects ◽  
Donor Cells ◽  
Alternative Agent ◽  
Conditioning Regimens ◽  
Total Body ◽  
And Function

Abstract Background A largely understudied strategy for reducing graft-versus-host disease (GvHD) is the modification of conditioning regimens. We have demonstrated that pre-transplant bendamustine (BEN) used in combination with total body irradiation (TBI) significantly reduces GvHD compared to the more commonly used cyclophosphamide (CY) + TBI. The short half-lives of BEN/CY (<4h), which are given 48h prior to transplant, indicate that these drugs do not directly affect the donor cells. Therefore, the striking improvement in GvHD by substituting CY with BEN must be due to differential effects on the host cells. Conditioned host immune cells diminish over time, but are the majority early after transplant and are able to critically interact with the infused donor cells at the earliest stages of GvHD pathogenesis. Methods Using an MHC-mismatched murine model of bone marrow transplantation (BMT) with C57BL/6 donors into BALB/c recipients (H2Kb into H2Kd), we evaluated the differential effects of BEN conditioning on host dendritic cells (DCs) early after transplant, as compared to CY conditioning. Transplant recipient mice were conditioned with BEN or CY on day -2 pre-BMT, and supplemented with 400cGy of total body irradiation on day -1. On days 1, 3, and 5 post-BMT, splenic pan-DCs were isolated and analyzed by flow cytometry to evaluate host (H2Kb-) DC phenotype and activation state. Further, on day 0 (without BMT), circulating leukocytes and splenic pan-DCs were isolated from conditioned mice and analyzed by flow cytometry, qPCR and allogeneic mixed leukocyte reactions. Results We found that BEN-conditioned pan DCs are less stimulatory of allogeneic T-cells than CY-treated DCs. BEN conditioning significantly alters host DC composition compared to CY conditioning, resulting in a significantly higher frequency and number of host CD8α+ DCs on days 1 and 3 post-BMT. BEN-conditioned CD8α+ DCs also display a highly regulatory phenotype (CD80highCD86low) and have greater suppressive ability compared to CY-conditioned CD8α+ DCs. Analysis of host DCs on day 0 (without BMT) revealed a significantly greater percentage of BEN-conditioned DCs positively expressing the Flt3 receptor compared to CY. Conclusions These findings advocate a potential role of Flt3L-dependent DCs, particularly CD8α+ DCs, in the mechanism by which BEN alters GvHD pathogenesis to limit morbidity and mortality. Thus, BEN may have advantages as an alternative agent to CY for pre-transplant conditioning in allogeneic BMT. Disclosures No relevant conflicts of interest to declare.

scholarly journals IKKε isoform switching governs the immune response against EV71 infection

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ya-Ling Chang ◽  
Yu-Wen Liao ◽  
Min-Hsuan Chen ◽  
Sui-Yuan Chang ◽  
Yao-Ting Huang ◽  
...  
Keyword(s):  
Host Cells ◽  
Ev71 Infection ◽  
Virus Propagation ◽  
Host Interactions ◽  
Reciprocal Interactions ◽  
Isoform Switching ◽  
Gene Regulatory ◽  
Potential Strategy ◽  
Antiviral Innate Immunity ◽  
Interferon Responses

AbstractThe reciprocal interactions between pathogens and hosts are complicated and profound. A comprehensive understanding of these interactions is essential for developing effective therapies against infectious diseases. Interferon responses induced upon virus infection are critical for establishing host antiviral innate immunity. Here, we provide a molecular mechanism wherein isoform switching of the host IKKε gene, an interferon-associated molecule, leads to alterations in IFN production during EV71 infection. We found that IKKε isoform 2 (IKKε v2) is upregulated while IKKε v1 is downregulated in EV71 infection. IKKε v2 interacts with IRF7 and promotes IRF7 activation through phosphorylation and translocation of IRF7 in the presence of ubiquitin, by which the expression of IFNβ and ISGs is elicited and virus propagation is attenuated. We also identified that IKKε v2 is activated via K63-linked ubiquitination. Our results suggest that host cells induce IKKε isoform switching and result in IFN production against EV71 infection. This finding highlights a gene regulatory mechanism in pathogen-host interactions and provides a potential strategy for establishing host first-line defense against pathogens.

scholarly journals Structural comparison of CD163 SRCR5 from different species sheds some light on its involvement in porcine reproductive and respiratory syndrome virus-2 infection in vitro

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Hongfang Ma ◽  
Rui Li ◽  
Longguang Jiang ◽  
Songlin Qiao ◽  
Xin-xin Chen ◽  
...  
Keyword(s):  
Scavenger Receptor ◽  
Host Cells ◽  
Respiratory Syndrome Virus ◽  
Swine Industry ◽  
Prrs Virus ◽  
Rich Domain ◽  
Serious Disease ◽  
The One ◽  
And Control

AbstractPorcine reproductive and respiratory syndrome (PRRS) is a serious disease burdening global swine industry. Infection by its etiological agent, PRRS virus (PRRSV), shows a highly restricted tropism of host cells and has been demonstrated to be mediated by an essential scavenger receptor (SR) CD163. CD163 fifth SR cysteine-rich domain (SRCR5) is further proven to play a crucial role during viral infection. Despite intense research, the involvement of CD163 SRCR5 in PRRSV infection remains to be elucidated. In the current study, we prepared recombinant monkey CD163 (moCD163) SRCR5 and human CD163-like homolog (hCD163L1) SRCR8, and determined their crystal structures. After comparison with the previously reported crystal structure of porcine CD163 (pCD163) SRCR5, these structures showed almost identical structural folds but significantly different surface electrostatic potentials. Based on these differences, we carried out mutational research to identify that the charged residue at position 534 in association with the one at position 561 were important for PRRSV-2 infection in vitro. Altogether the current work sheds some light on CD163-mediated PRRSV-2 infection and deepens our understanding of the viral pathogenesis, which will provide clues for prevention and control of PRRS.

scholarly journals Correction to Patchy Amphiphilic Dendrimers Bind Adenovirus and Control Its Host Interactions and in Vivo Distribution

ACS Nano ◽  
2021 ◽  
Author(s):  
Yuzhou Wu ◽  
Longjie Li ◽  
Larissa Frank ◽  
Jessica Wagner ◽  
Patrizia Andreozzi ◽  
...  
Keyword(s):  
Host Interactions ◽  
In Vivo Distribution ◽  
Amphiphilic Dendrimers ◽  
And Control

scholarly journals Diagnosis and Therapeutic Management of Liver Fibrosis by microRNA

2021 ◽  
Vol 22 (15) ◽  
pp. 8139
Author(s):  
Tomoko Tadokoro ◽  
Asahiro Morishita ◽  
Tsutomu Masaki
Keyword(s):  
Liver Fibrosis ◽  
Viral Infections ◽  
Primary Biliary Cholangitis ◽  
Medical Need ◽  
Key Factor ◽  
Complications Of Cirrhosis ◽  
And Control ◽  
Functional Rnas ◽  
Remarkable Progress ◽  
Made In

Remarkable progress has been made in the treatment and control of hepatitis B and C viral infections. However, fundamental treatments for diseases in which liver fibrosis is a key factor, such as cirrhosis, alcoholic/nonalcoholic steatohepatitis, autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis, are still under development and remain an unmet medical need. To solve this problem, it is essential to elucidate the pathogenesis of liver fibrosis in detail from a molecular and cellular perspective and to develop targeted therapeutic agents based on this information. Recently, microRNAs (miRNAs), functional RNAs of 22 nucleotides, have been shown to be involved in the pathogenesis of liver fibrosis. In addition, extracellular vesicles called “exosomes” have been attracting attention, and research is being conducted to establish noninvasive and extremely sensitive biomarkers using miRNAs in exosomes. In this review, we summarize miRNAs directly involved in liver fibrosis, miRNAs associated with diseases leading to liver fibrosis, and miRNAs related to complications of cirrhosis. We will also discuss the efficacy of each miRNA as a biomarker of liver fibrosis and pathology, and its potential application as a therapeutic agent.

scholarly journals N-Glycolyl GM1 Ganglioside as a Receptor for Simian Virus 40

2007 ◽  
Vol 81 (23) ◽  
pp. 12846-12858 ◽  
Author(s):  
Maria A. Campanero-Rhodes ◽  
Alicia Smith ◽  
Wengang Chai ◽  
Sandro Sonnino ◽  
Laura Mauri ◽  
...  
Keyword(s):  
Simian Virus 40 ◽  
High Specificity ◽  
Simian Virus ◽  
Receptor Expression ◽  
Host Cells ◽  
Gm1 Ganglioside ◽  
Ganglioside Gm1 ◽  
Virus Binding ◽  
Host Interactions ◽  
Sv40 Infection

ABSTRACT Carbohydrate microarrays have emerged as powerful tools in analyses of microbe-host interactions. Using a microarray with 190 sequence-defined oligosaccharides in the form of natural glycolipids and neoglycolipids representative of diverse mammalian glycans, we examined interactions of simian virus 40 (SV40) with potential carbohydrate receptors. While the results confirmed the high specificity of SV40 for the ganglioside GM1, they also revealed that N-glycolyl GM1 ganglioside [GM1(Gc)], which is characteristic of simian species and many other nonhuman mammals, is a better ligand than the N-acetyl analog [GM1(Ac)] found in mammals, including humans. After supplementing glycolipid-deficient GM95 cells with GM1(Ac) and GM1(Gc) gangliosides and the corresponding neoglycolipids with phosphatidylethanolamine lipid groups, it was found that GM1(Gc) analogs conferred better virus binding and infectivity. Moreover, we visualized the interaction of NeuGc with VP1 protein of SV40 by molecular modeling and identified a conformation for GM1(Gc) ganglioside in complex with the virus VP1 pentamer that is compatible with its presentation as a membrane receptor. Our results open the way not only to detailed studies of SV40 infection in relation to receptor expression in host cells but also to the monitoring of changes that may occur with time in receptor usage by the virus.

scholarly journals What is the mechanism for persistent coexistence of drug-susceptible and drug-resistant strains of Streptococcus pneumoniae ?

2009 ◽  
Vol 7 (47) ◽  
pp. 905-919 ◽  
Author(s):  
Caroline Colijn ◽  
Ted Cohen ◽  
Christophe Fraser ◽  
William Hanage ◽  
Edward Goldstein ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Infectious Diseases ◽  
Multiple Infection ◽  
Drug Resistant ◽  
Host Interactions ◽  
Resistant Strains ◽  
Neutral Models ◽  
Drug Resistant Strains ◽  
And Control

The rise of antimicrobial resistance in many pathogens presents a major challenge to the treatment and control of infectious diseases. Furthermore, the observation that drug-resistant strains have risen to substantial prevalence but have not replaced drug-susceptible strains despite continuing (and even growing) selective pressure by antimicrobial use presents an important problem for those who study the dynamics of infectious diseases. While simple competition models predict the exclusion of one strain in favour of whichever is ‘fitter’, or has a higher reproduction number, we argue that in the case of Streptococcus pneumoniae there has been persistent coexistence of drug-sensitive and drug-resistant strains, with neither approaching 100 per cent prevalence. We have previously proposed that models seeking to understand the origins of coexistence should not incorporate implicit mechanisms that build in stable coexistence ‘for free’. Here, we construct a series of such ‘structurally neutral’ models that incorporate various features of bacterial spread and host heterogeneity that have been proposed as mechanisms that may promote coexistence. We ask to what extent coexistence is a typical outcome in each. We find that while coexistence is possible in each of the models we consider, it is relatively rare, with two exceptions: (i) allowing simultaneous dual transmission of sensitive and resistant strains lets coexistence become a typical outcome, as does (ii) modelling each strain as competing more strongly with itself than with the other strain, i.e. self-immunity greater than cross-immunity. We conclude that while treatment and contact heterogeneity can promote coexistence to some extent, the in-host interactions between strains, particularly the interplay between coinfection, multiple infection and immunity, play a crucial role in the long-term population dynamics of pathogens with drug resistance.

scholarly journals MicroRNAs and Mammarenaviruses: Modulating Cellular Metabolism

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2525
Author(s):  
Jorlan Fernandes ◽  
Renan Lyra Miranda ◽  
Elba Regina Sampaio de Lemos ◽  
Alexandro Guterres
Keyword(s):  
Metabolic Pathways ◽  
Molecular Mechanisms ◽  
Viral Infections ◽  
Mirna Expression Profile ◽  
Metabolic Reprogramming ◽  
Host Cells ◽  
Emerging Viruses ◽  
Cellular Mirnas ◽  
Host Interactions ◽  
Causative Agents

Mammarenaviruses are a diverse genus of emerging viruses that include several causative agents of severe viral hemorrhagic fevers with high mortality in humans. Although these viruses share many similarities, important differences with regard to pathogenicity, type of immune response, and molecular mechanisms during virus infection are different between and within New World and Old World viral infections. Viruses rely exclusively on the host cellular machinery to translate their genome, and therefore to replicate and propagate. miRNAs are the crucial factor in diverse biological processes such as antiviral defense, oncogenesis, and cell development. The viral infection can exert a profound impact on the cellular miRNA expression profile, and numerous RNA viruses have been reported to interact directly with cellular miRNAs and/or to use these miRNAs to augment their replication potential. Our present study indicates that mammarenavirus infection induces metabolic reprogramming of host cells, probably manipulating cellular microRNAs. A number of metabolic pathways, including valine, leucine, and isoleucine biosynthesis, d-Glutamine and d-glutamate metabolism, thiamine metabolism, and pools of several amino acids were impacted by the predicted miRNAs that would no longer regulate these pathways. A deeper understanding of mechanisms by which mammarenaviruses handle these signaling pathways is critical for understanding the virus/host interactions and potential diagnostic and therapeutic targets, through the inhibition of specific pathologic metabolic pathways.

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