scholarly journals The Natural History of BK Polyomavirus and the Host Immune Response After Stem Cell Transplantation

2019 ◽  
Author(s):  
Benjamin L Laskin ◽  
Michelle R Denburg ◽  
Susan L Furth ◽  
Taylor Moatz ◽  
Michelle Altrich ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Cell Transplantation ◽  
Kidney Function ◽  
Hematopoietic Cell Transplantation ◽  
Antiviral Treatment ◽  
Host Immune Response ◽  
Risk Of Death ◽  
Asymptomatic Patients ◽  
Bk Polyomavirus

Abstract Background BK polyomavirus (BKPyV) is associated with symptomatic hemorrhagic cystitis after hematopoietic cell transplantation (HCT). Little is known about the host immune response, effectiveness of antiviral treatment, or impact of asymptomatic replication on long-term kidney function. Methods In children and young adults undergoing allogeneic HCT, we quantified BKPyV viruria and viremia (pre-HCT and at Months 1–4, 8, 12, and 24 post-HCT) and tested associations of peak viremia ≥10 000 or viruria ≥109 copies/mL with estimated kidney function (glomerular filtration rate, eGFR) and overall survival at 2 years posttransplant. We examined the factors associated with viral clearance by Month 4, including BKPyV-specific T cells by enzyme-linked immune absorbent spot at Month 3 and cidofovir use. Results We prospectively enrolled 193 participants (median age 10 years) and found that 18% had viremia ≥10 000 copies/mL and 45% had viruria ≥109 copies/mL in the first 3 months post-HCT. Among the 147 participants without cystitis (asymptomatic), 58 (40%) had any viremia. In the entire cohort and asymptomatic subset, having viremia ≥10 000 copies/mL was associated with a lower creatinine/cystatin C eGFR at 2 years post-HCT. Viremia ≥10 000 copies/mL was associated with a higher risk of death (adjusted hazard ratio, 2.2; 95% confidence interval, 1.1–4.2). Clearing viremia was associated with detectable BKPyV-specific T cells and having viremia <10 000 copies/mL, but not cidofovir exposure. Conclusions Screening for BKPyV viremia after HCT identifies asymptomatic patients at risk for kidney disease and reduced survival. These data suggest potential changes to clinical practice, including prospective monitoring for BKPyV viremia to test virus-specific T cells to prevent or treat BKPyV replication.

scholarly journals Modified T cells as therapeutic agents

Hematology ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 296-302
Author(s):  
Nathan Singh
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Lymphocytes ◽  
B Cell ◽  
Cell Transplantation ◽  
Immune Reconstitution ◽  
Hematopoietic Cell Transplantation ◽  
Viral Infections ◽  
Therapeutic Agents ◽  
B Cell Malignancies

Abstract Immunotherapy is now a well-established modality in the treatment of cancer. Although several platforms to redirect the immune response exist, the use of genetically modified T cells has garnered particular attention in recent years. This is due, in large part, to their success in the treatment of B-cell malignancies. Adoptively transferred T cells have also demonstrated efficacy in the treatment of systemic viral infections that occur following hematopoietic cell transplantation prior to immune reconstitution. Here we discuss the techniques that enable redirection of T lymphocytes to treat cancer or infection and the current indications for these therapies.

scholarly journals The Role of Immune Checkpoint Molecules for Relapse After Allogeneic Hematopoietic Cell Transplantation

2021 ◽  
Vol 12 ◽  
Author(s):  
Natalie Köhler ◽  
Dietrich Alexander Ruess ◽  
Rebecca Kesselring ◽  
Robert Zeiser
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Cell Transplantation ◽  
Immune Checkpoint ◽  
Hematopoietic Cell Transplantation ◽  
Immune Checkpoint Blockade ◽  
Hematopoietic Cell ◽  
Allogeneic Hematopoietic Cell Transplantation ◽  
Immune Checkpoint Molecules

Immune checkpoint molecules represent physiological brakes of the immune system that are essential for the maintenance of immune homeostasis and prevention of autoimmunity. By inhibiting these negative regulators of the immune response, immune checkpoint blockade can increase anti-tumor immunity, but has been primarily successful in solid cancer therapy and Hodgkin lymphoma so far. Allogeneic hematopoietic cell transplantation (allo-HCT) is a well-established cellular immunotherapy option with the potential to cure hematological cancers, but relapse remains a major obstacle. Relapse after allo-HCT is mainly thought to be attributable to loss of the graft-versus-leukemia (GVL) effect and hence escape of tumor cells from the allogeneic immune response. One potential mechanism of immune escape from the GVL effect is the inhibition of allogeneic T cells via engagement of inhibitory receptors on their surface including PD-1, CTLA-4, TIM3, and others. This review provides an overview of current evidence for a role of immune checkpoint molecules for relapse and its treatment after allo-HCT, as well as discussion of the immune mediated side effect graft-vs.-host disease. We discuss the expression of different immune checkpoint molecules on leukemia cells and T cells in patients undergoing allo-HCT. Furthermore, we review mechanistic insights gained from preclinical studies and summarize clinical trials assessing immune checkpoint blockade for relapse after allo-HCT.

scholarly journals Longitudinal single-cell immune profiling revealed distinct innate immune response in asymptomatic COVID-19 patients

2020 ◽  
Author(s):  
Xiang-Na Zhao ◽  
Yue You ◽  
Guo-Lin Wang ◽  
Hui-Xia Gao ◽  
Xiao-Ming Cui ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Innate Immune Response ◽  
Clonal Expansion ◽  
Innate Immune ◽  
Type I ◽  
Severe Condition ◽  
Asymptomatic Patients

SUMMARYRecent studies have characterized the single-cell immune landscape of host immune response of coronavirus disease 2019 (COVID-19), specifically focus on the severe condition. However, the immune response in mild or even asymptomatic patients remains unclear. Here, we performed longitudinal single-cell transcriptome sequencing and T cell/B cell receptor sequencing on 3 healthy donors and 10 COVID-19 patients with asymptomatic, moderate, and severe conditions. We found asymptomatic patients displayed distinct innate immune responses, including increased CD56briCD16− NK subset, which was nearly missing in severe condition and enrichment of a new Th2-like cell type/state expressing a ciliated cell marker. Unlike that in moderate condition, asymptomatic patients lacked clonal expansion of effector CD8+ T cells but had a robust effector CD4+ T cell clonal expansion, coincide with previously detected SARS-CoV-2-reactive CD4+ T cells in unexposed individuals. Moreover, NK and effector T cells in asymptomatic patients have upregulated cytokine related genes, such as IFNG and XCL2. Our data suggest early innate immune response and type I immunity may contribute to the asymptomatic phenotype in COVID-19 disease, which could in turn deepen our understanding of severe COVID-19 and guide early prediction and therapeutics.

Fecal microbiota diversity disruption and clinical outcomes after auto-HCT: a multicenter observational study

Blood ◽  
2020 ◽  
Author(s):  
Niloufer Khan ◽  
Sarah Lindner ◽  
Antonio LC Gomes ◽  
Sean M. Devlin ◽  
Gunjan Shah ◽  
...  
Keyword(s):  
Observational Study ◽  
Cell Transplantation ◽  
Hematopoietic Cell Transplantation ◽  
The United States ◽  
Fecal Microbiota ◽  
Ribosomal Gene ◽  
Hematopoietic Cell ◽  
High Dose ◽  
Risk Of Death ◽  
Microbiota Diversity

We have previously described clinically relevant reductions in fecal microbiota diversity of patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT). Recipients of high-dose chemotherapy and autologous hematopoietic cell transplantation (auto-HCT) incur similar antibiotic exposures and nutritional alterations. To characterize the fecal microbiota in the auto-HCT population, we analyzed 1,161 fecal samples collected from 534 adult recipients of auto-HCT for lymphoma, myeloma and amyloidosis in an observational study conducted at two transplant centers in the United States. Using 16S ribosomal gene sequencing, we assessed fecal microbiota diversity as measured by the inverse Simpson index, and composition. At both centers, early pre-transplant fecal microbiota diversity was lower than in healthy control subjects and decreased further during the course of transplantation. Loss of diversity and domination by specific bacterial taxa occurred during auto-HCT in patterns similar to allo-HCT. Above-median fecal intestinal diversity in the peri-engraftment period was associated with decreased risk of death or progression (PFS HR 0.46 [95% CI, 0.26-0.82], P=0.008), adjusting for disease and disease status. This suggests that further investigation into the health of the intestinal microbiota in auto-HCT patients and post-transplant outcomes should be undertaken.

scholarly journals Reconstitution of T Cell Subsets Following Allogeneic Hematopoietic Cell Transplantation

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1974 ◽  
Author(s):  
Linde Dekker ◽  
Coco de Koning ◽  
Caroline Lindemans ◽  
Stefan Nierkens
Keyword(s):  
Overall Survival ◽  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Hematopoietic Cell Transplantation ◽  
Cell Subset ◽  
Γδ T Cells ◽  
Hematopoietic Cell ◽  
T Cell Subsets ◽  
T Cell Subset

Allogeneic (allo) hematopoietic cell transplantation (HCT) is the only curative treatment option for patients suffering from chemotherapy-refractory or relapsed hematological malignancies. The occurrence of morbidity and mortality after allo-HCT is still high. This is partly correlated with the immunological recovery of the T cell subsets, of which the dynamics and relations to complications are still poorly understood. Detailed information on T cell subset recovery is crucial to provide tools for better prediction and modulation of adverse events. Here, we review the current knowledge regarding CD4+ and CD8+ T cells, γδ T cells, iNKT cells, Treg cells, MAIT cells and naive and memory T cell reconstitution, as well as their relations to outcome, considering different cell sources and immunosuppressive therapies. We conclude that the T cell subsets reconstitute in different ways and are associated with distinct adverse and beneficial events; however, adequate reconstitution of all the subsets is associated with better overall survival. Although the exact mechanisms involved in the reconstitution of each T cell subset and their associations with allo-HCT outcome need to be further elucidated, the data and suggestions presented here point towards the development of individualized approaches to improve their reconstitution. This includes the modulation of immunotherapeutic interventions based on more detailed immune monitoring, aiming to improve overall survival changes.

scholarly journals Donor-Derived CD4+ T Cells and Human Herpesvirus 6B Detection After Allogeneic Hematopoietic Cell Transplantation

2020 ◽  
Author(s):  
Derek J Hanson ◽  
Hu Xie ◽  
Danielle M Zerr ◽  
Wendy M Leisenring ◽  
Keith R Jerome ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Cd4 T Cells ◽  
Hematopoietic Cell Transplantation ◽  
Mononuclear Cells ◽  
Human Herpesvirus ◽  
Hematopoietic Cell ◽  
Allogeneic Hematopoietic Cell Transplantation ◽  
Peripheral Blood Mononuclear

Abstract We sought to determine whether donor-derived human herpesvirus (HHV) 6B–specific CD4+ T-cell abundance is correlated with HHV-6B detection after allogeneic hematopoietic cell transplantation. We identified 33 patients who received HLA-matched, non–T-cell–depleted, myeloablative allogeneic hematopoietic cell transplantation and underwent weekly plasma polymerase chain reaction testing for HHV-6B for 100 days thereafter. We tested donor peripheral blood mononuclear cells for HHV-6B–specific CD4+ T cells. Patients with HHV-6B detection above the median peak viral load (200 copies/mL) received approximately 10-fold fewer donor-derived total or HHV-6B–specific CD4+ T cells than those with peak HHV-6B detection at ≤200 copies/mL or with no HHV-6B detection. These data suggest the importance of donor-derived immunity for controlling HHV-6B reactivation.

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