scholarly journals DNA damage and repair in peripheral blood mononuclear cells after internal ex vivo irradiation of patient blood with 131I

Author(s):  
S. Schumann ◽  
H. Scherthan ◽  
K. Pfestroff ◽  
S. Schoof ◽  
A. Pfestroff ◽  
...  

Abstract Aim The aim of this study was to provide a systematic approach to characterize DNA damage induction and repair in isolated peripheral blood mononuclear cells (PBMCs) after internal ex vivo irradiation with [131I]NaI. In this approach, we tried to mimic ex vivo the irradiation of patient blood in the first hours after radioiodine therapy. Material and methods Blood of 33 patients of two centres was collected immediately before radioiodine therapy of differentiated thyroid cancer (DTC) and split into two samples. One sample served as non-irradiated control. The second sample was exposed to ionizing radiation by adding 1 ml of [131I]NaI solution to 7 ml of blood, followed by incubation at 37 °C for 1 h. PBMCs of both samples were isolated, split in three parts each and (i) fixed in 70% ethanol and stored at − 20 °C directly (0 h) after irradiation, (ii) after 4 h and (iii) 24 h after irradiation and culture in RPMI medium. After immunofluorescence staining microscopically visible co-localizing γ-H2AX + 53BP1 foci were scored in 100 cells per sample as biomarkers for radiation-induced double-strand breaks (DSBs). Results Thirty-two of 33 blood samples could be analysed. The mean absorbed dose to the blood in all irradiated samples was 50.1 ± 2.3 mGy. For all time points (0 h, 4 h, 24 h), the average number of γ-H2AX + 53BP1 foci per cell was significantly different when compared to baseline and the other time points. The average number of radiation-induced foci (RIF) per cell after irradiation was 0.72 ± 0.16 at t = 0 h, 0.26 ± 0.09 at t = 4 h and 0.04 ± 0.09 at t = 24 h. A monoexponential fit of the mean values of the three time points provided a decay rate of 0.25 ± 0.05 h−1, which is in good agreement with data obtained from external irradiation with γ- or X-rays. Conclusion This study provides novel data about the ex vivo DSB repair in internally irradiated PBMCs of patients before radionuclide therapy. Our findings show, in a large patient sample, that efficient repair occurs after internal irradiation with 50 mGy absorbed dose, and that the induction and repair rate after 131I exposure is comparable to that of external irradiation with γ- or X-rays.

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 388 ◽  
Author(s):  
Sarah Schumann ◽  
Harry Scherthan ◽  
Torsten Frank ◽  
Constantin Lapa ◽  
Jessica Müller ◽  
...  

The aim was to investigate the induction and repair of radiation-induced DNA double-strand breaks (DSBs) as a function of the absorbed dose to the blood of patients undergoing PET/CT examinations with [68Ga]Ga-PSMA. Blood samples were collected from 15 patients before and at four time points after [68Ga]Ga-PSMA administration, both before and after the PET/CT scan. Absorbed doses to the blood were calculated. In addition, blood samples with/without contrast agent from five volunteers were irradiated ex vivo by CT while measuring the absorbed dose. Leukocytes were isolated, fixed, and stained for co-localizing γ-H2AX+53BP1 DSB foci that were enumerated manually. In vivo, a significant increase in γ-H2AX+53BP1 foci compared to baseline was observed at all time points after administration, although the absorbed dose to the blood by 68Ga was below 4 mGy. Ex vivo, the increase in radiation-induced foci depended on the absorbed dose and the presence of contrast agent, which could have caused a dose enhancement. The CT-dose contribution for the patients was estimated at about 12 mGy using the ex vivo calibration. The additional number of DSB foci induced by CT, however, was comparable to the one induced by 68Ga. The significantly increased foci numbers after [68Ga]Ga-PSMA administration may suggest a possible low-dose hypersensitivity.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5738-5738
Author(s):  
Miguel Blanquer Blanquer ◽  
Carmen Alguero ◽  
Pilar Menchon ◽  
Assumpta Ferrer ◽  
Pilar Martínez Avilés ◽  
...  

Abstract Cryopreservation of products rich in progenitor cells is mandatory for the feasibility of autologous hematopietic progenitor cells transplants. The most used product nowadays is the apheresis of mobilized peripheral blood mononuclear cells. However, cryopreservation implies the use of cryoprotectant molecules, such as DMSO, that can be toxic for the patients. Moreover, the thawing of the product goes with some unavoidable cell death and liberation of cytoplasmic content such as cytokines to the medium. And so, adverse reactions during the product infusion are not infrequent. Our group has demonstrated that washing the thawed apheresis products both with Voluven or with normal saline plus 5% albumin (NSA) is able to almost completely avoid infusion reactions without losing CD34+ cells. Here we wanted to know whether it also had the benefit of extending CD34+ viability for 24 hours after washing. METHODS: We thawed 3 spare peripheral blood mononuclear cells apheresis products that had been cryopreserved with 9%DMSO. Ten mL of each product were separated and the remaining volume was splitted in 2 bags to be washed either with Voluven or NSA. Sepax 2 smartwash automatic program was used to wash the cells. The washed cells were stored at 4ºC and a sample was taken and immediately analyzed at 0h, 1h, 2h, 4h and 24h. At the same time points 10 mL of each bag were separated and kept 30 min. at room temperature (RT) before being analyzed. A blood count was performed on all the samples. Flow cytometry was used to measure CD45+ and CD34+ cells viability by 7AAD staining. RESULTS: The mean CD45+ cells viability was 69% after thawing the cells ,81% immediately after washing them with Voluven, and 81%, 80%, 79% and 73% 1h, 2h, 4h and 24h after the wash. When using NSA the mean CD45+ viability was 79%, 92%, 93%, 92%, 93% and 87% at the same time points. When the samples were kept for 30 additional minutes at RT, the mean CD45+ viability was 78%, 81%, 84%, 82%, 84% and 81% with Voluven, and 80%, 92%, 94%, 91%, 95% and 86% with NSA. Regarding CD34+ cells, when washed with Voluven the mean viability was 46%, 87%, 87%, 92%, 83% and 69%, while it was 61%, 91%, 91%, 92%, 89% and 84% when NSA was used. The mean CD34+ cells viability results after 30' at RT for each time point were 79%, 90%, 82%, 91%, 82% and 81% with Voluven and 85%, 90%, 90%, 94%, 93% and 86% with NSA. Moreover the mean viable CD34+ cells recovery at 24h was 90.94% for Voluven and 87,88% for NSA. CONCLUSIONS: We have obtained an excellent stability of the CD34+ cells viability for 24h after washing the mobilized mononuclear cells apheresis products both with Voluven and with NSA when the products are stored at 4ºC. Moreover, the viability is not affected when the cells are kept for an additional 30' at RT. The viable CD34+ cells loss at 24h was scarce. Disclosures Blanquer Blanquer: Pfizer: Research Funding.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nan Xiao ◽  
Meng Nie ◽  
Huanhuan Pang ◽  
Bohong Wang ◽  
Jieli Hu ◽  
...  

AbstractCytokine release syndrome (CRS) is a major cause of the multi-organ injury and fatal outcome induced by SARS-CoV-2 infection in severe COVID-19 patients. Metabolism can modulate the immune responses against infectious diseases, yet our understanding remains limited on how host metabolism correlates with inflammatory responses and affects cytokine release in COVID-19 patients. Here we perform both metabolomics and cytokine/chemokine profiling on serum samples from healthy controls, mild and severe COVID-19 patients, and delineate their global metabolic and immune response landscape. Correlation analyses show tight associations between metabolites and proinflammatory cytokines/chemokines, such as IL-6, M-CSF, IL-1α, IL-1β, and imply a potential regulatory crosstalk between arginine, tryptophan, purine metabolism and hyperinflammation. Importantly, we also demonstrate that targeting metabolism markedly modulates the proinflammatory cytokines release by peripheral blood mononuclear cells isolated from SARS-CoV-2-infected rhesus macaques ex vivo, hinting that exploiting metabolic alterations may be a potential strategy for treating fatal CRS in COVID-19.


Author(s):  
An Aerts ◽  
Uta Eberlein ◽  
Sören Holm ◽  
Roland Hustinx ◽  
Mark Konijnenberg ◽  
...  

Executive SummaryWith an increasing variety of radiopharmaceuticals for diagnostic or therapeutic nuclear medicine as valuable diagnostic or treatment option, radiobiology plays an important role in supporting optimizations. This comprises particularly safety and efficacy of radionuclide therapies, specifically tailored to each patient. As absorbed dose rates and absorbed dose distributions in space and time are very different between external irradiation and systemic radionuclide exposure, distinct radiation-induced biological responses are expected in nuclear medicine, which need to be explored. This calls for a dedicated nuclear medicine radiobiology. Radiobiology findings and absorbed dose measurements will enable an improved estimation and prediction of efficacy and adverse effects. Moreover, a better understanding on the fundamental biological mechanisms underlying tumor and normal tissue responses will help to identify predictive and prognostic biomarkers as well as biomarkers for treatment follow-up. In addition, radiobiology can form the basis for the development of radiosensitizing strategies and radioprotectant agents. Thus, EANM believes that, beyond in vitro and preclinical evaluations, radiobiology will bring important added value to clinical studies and to clinical teams. Therefore, EANM strongly supports active collaboration between radiochemists, radiopharmacists, radiobiologists, medical physicists, and physicians to foster research toward precision nuclear medicine.


Author(s):  
S. Schumann ◽  
U. Eberlein ◽  
C. Lapa ◽  
J. Müller ◽  
S. Serfling ◽  
...  

Abstract Purpose One therapy option for prostate cancer patients with bone metastases is the use of [223Ra]RaCl2. The α-emitter 223Ra creates DNA damage tracks along α-particle trajectories (α-tracks) in exposed cells that can be revealed by immunofluorescent staining of γ-H2AX+53BP1 DNA double-strand break markers. We investigated the time- and absorbed dose-dependency of the number of α-tracks in peripheral blood mononuclear cells (PBMCs) of patients undergoing their first therapy with [223Ra]RaCl2. Methods Multiple blood samples from nine prostate cancer patients were collected before and after administration of [223Ra]RaCl2, up to 4 weeks after treatment. γ-H2AX- and 53BP1-positive α-tracks were microscopically quantified in isolated and immuno-stained PBMCs. Results The absorbed doses to the blood were less than 6 mGy up to 4 h after administration and maximally 16 mGy in total. Up to 4 h after administration, the α-track frequency was significantly increased relative to baseline and correlated with the absorbed dose to the blood in the dose range < 3 mGy. In most of the late samples (24 h – 4 weeks after administration), the α-track frequency remained elevated. Conclusion The γ-H2AX+53BP1 assay is a potent method for detection of α-particle-induced DNA damages during treatment with or after accidental incorporation of radionuclides even at low absorbed doses. It may serve as a biomarker discriminating α- from β-emitters based on damage geometry.


Author(s):  
Véronique Avettand-Fenoel ◽  
Jérôme Lechenadec ◽  
Mariama Sadjo Diallo ◽  
Marine Fillion ◽  
Adeline Melard ◽  
...  

Abstract Background Early combined antiretroviral therapy (cART) limits the total HIV-DNA load in children. However, data on its impact in older children and adolescents remain scarce. This study aims to compare HIV reservoirs in children (5-12 years) and adolescents (13-17 years) who started cART before 6 months (early (E-)group) or after 2 years old (late (L-)group). Methods The ANRS-EP59-CLEAC study prospectively enrolled 76 HIV-1 perinatally-infected patients who reached HIV-RNA&lt;400 copies/mL less than 24 months after cART initiation, regardless of subsequent viral suppression (E-group: 27 children, 9 adolescents; L-group: 19 children, 21 adolescents). Total and integrated HIV-DNA were quantified in blood and in CD4+ T cell subsets. A substudy assessed HIV reservoir inducibility after ex vivo peripheral blood mononuclear cells (PBMCs) stimulation. Results Total HIV-DNA levels were lower in early- than late-treated patients (Children: 2.14 vs 2.87 log cp/million PBMCs, p&lt;0.0001; Adolescents: 2.25 vs 2.74log, p&lt;0.0001). Low reservoir was independently associated with treatment precocity, protective HLA and low cumulative viremia since cART initiation. The 60 participants with undetectable integrated HIV-DNA started cART earlier than the other patients (4 vs 54 months, p=0.03). In those with sustained virological control, transitional memory and effector memory CD4+T cells were less infected in the E-group than in the L-group (p=0.03 and 0.02, respectively). Viral inducibility of reservoir cells after normalization to HIV-DNA levels was similar between the groups. Conclusions Early cART results in a smaller blood HIV reservoir until adolescence, but all tested participants had an inducible reservoir. This deserves cautious consideration for HIV remission strategies.


Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3843
Author(s):  
Jeffrey R. Whiteaker ◽  
Tao Wang ◽  
Lei Zhao ◽  
Regine M. Schoenherr ◽  
Jacob J. Kennedy ◽  
...  

The ATM serine/threonine kinase (HGNC: ATM) is involved in initiation of repair of DNA double-stranded breaks, and ATM inhibitors are currently being tested as anti-cancer agents in clinical trials, where pharmacodynamic (PD) assays are crucial to help guide dose and scheduling and support mechanism of action studies. To identify and quantify PD biomarkers of ATM inhibition, we developed and analytically validated a 51-plex assay (DDR-2) quantifying protein expression and DNA damage-responsive phosphorylation. The median lower limit of quantification was 1.28 fmol, the linear range was over 3 orders of magnitude, the median inter-assay variability was 11% CV, and 86% of peptides were stable for storage prior to analysis. Use of the assay was demonstrated to quantify signaling following ionizing radiation-induced DNA damage in both immortalized lymphoblast cell lines and primary human peripheral blood mononuclear cells, identifying PD biomarkers for ATM inhibition to support preclinical and clinical studies.


2002 ◽  
Vol 76 (15) ◽  
pp. 7418-7429 ◽  
Author(s):  
O. Martin Williams ◽  
Keith W. Hart ◽  
Eddie C. Y. Wang ◽  
Colin M. Gelder

ABSTRACT Human papillomavirus type 11 (HPV-11) infection causes genital warts and recurrent respiratory papillomatosis. While there is compelling evidence that CD4+ T cells play an important role in immune surveillance of HPV-associated diseases, little is known about human CD4+ T-cell recognition of HPV-11. We have investigated the CD4+ T-cell responses of 25 unrelated healthy donors to HPV-11 L1 virus-like particles (VLP). CD4+ T-cell lines from 21 of 25 donors were established. Cell sorting experiments carried out on cells from six donors demonstrated that the response was located in the CD45RAlow CD45ROhigh memory T-cell population. To determine the peptide specificity of these responses, epitope selection was analyzed by using 95 15-mer peptides spanning the entire HPV-11 L1 protein. No single region of L1 was immunodominant; responders recognized between 1 and 10 peptides, located throughout the protein, and peptide responses fell into clear HLA class II restricted patterns. Panels of L1 peptides specific for skin and genital HPV were used to show that the L1 CD4+ T-cell responses were cross-reactive. The degree of cross-reactivity was inversely related to the degree of L1 sequence diversity between these viruses. Finally, responses to HPV-11 L1 peptides were elicited from ex vivo CD45RO+ peripheral blood mononuclear cells, demonstrating that recognition of HPV-11 was a specific memory response and not due to in vitro selection during tissue culture. This is the first study of CD4+ T-cell responses to HPV-11 in healthy subjects and demonstrates marked cross-reactivity with other skin and genital HPV types. This cross-reactivity may be of significance for vaccine strategies against HPV-associated clinical diseases.


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