Showing papers by "Eva Rohde published in 2022"

Persistence of Naturally Acquired and Functional SARS-CoV-2 Antibodies in Blood Donors One Year after Infection

Abstract: The developmental course of antibodies produced after a SARS-CoV-2 infection has been insufficiently investigated so far. Therefore, the aim of this study was to investigate the dynamics of SARS-CoV-2 antibody levels against the viral nucleocapsid- and spike-protein among Austrian blood donors as a representative group of a supposedly healthy population within the first year after a SARS-CoV-2 infection. The impact of age, sex, vaccination status, AB0-blood group and awareness about the infection was evaluated. Our study shows that the level of anti-N antibodies is declining, while anti-S antibody levels remain stable. Antibodies detected were functional in vitro. Age, sex and blood group do not influence antibody dynamics. However, blood group AB shows significantly lower antibody levels and in vitro functionality compared to other blood groups. Our data reveal that one out of five individuals was not aware of a previous SARS-CoV-2 infection and that the disease course neither affects the level of antibody production nor the in vitro functionality. We also found that 14% of participants show persisting COVID-19-related symptoms for up to nine months. Our results provide valuable insights into the dynamics of the immune response after a SARS-CoV-2 infection in a representative cohort of adult blood donors in Central Europe.

Enhancing Functional Recovery Through Intralesional Application of Extracellular Vesicles in a Rat Model of Traumatic Spinal Cord Injury

Abstract: Local inflammation plays a pivotal role in the process of secondary damage after spinal cord injury. We recently reported that acute intravenous application of extracellular vesicles (EVs) secreted by human umbilical cord mesenchymal stromal cells dampens the induction of inflammatory processes following traumatic spinal cord injury. However, systemic application of EVs is associated with delayed delivery to the site of injury and the necessity for high doses to reach therapeutic levels locally. To resolve these two constraints, we injected EVs directly at the lesion site acutely after spinal cord injury. We report here that intralesional application of EVs resulted in a more robust improvement of motor recovery, assessed with the BBB score and sub-score, as compared to the intravenous delivery. Moreover, the intralesional application was more potent in reducing inflammation and scarring after spinal cord injury than intravenous administration. Hence, the development of EV-based therapy for spinal cord injury should aim at an early application of vesicles close to the lesion.

The systemic immune profile predicts the development of infections in patients with spinal cord injuries.

Abstract: Patients with spinal cord injury (SCI) frequently develop infections that may affect quality of life, be life-threatening, and impair their neurological recovery in the acute and subacute injury phase. Therefore, identifying SCI patients at risk for developing infections in this stage is of utmost importance. We determined the systemic levels of immune cell populations, cytokines, chemokines and growth factors in 81 patients with traumatic SCI at 4 weeks after injury and compared them with those of 26 age-matched healthy control subjects. Patients who are going to develop infections between 4 and 16 weeks after injury exhibit higher number of neutrophils and eosinophils, as well as lower numbers of lymphocytes and eotaxin-1 (CCL11) levels. Accordingly, lasso logistic regression shows that incomplete lesions (AIS C and D grades), the levels of eotaxin-1, and the number of lymphocytes, basophils and monocytes are predictive of lower odds of infections. On the other hand, the number of neutrophils and eosinophils as well as, in a lesser extent, the levels of IP-10 (CXCL10), MCP-1 (CCL2), BDNF and VEGF-A are predictors of greater odds of infections. Overall, our results point to systemic immune disbalance after SCI as predictors of infections in a period when infections may greatly interfere with neurological and functional recovery and suggest new pathways and players to further explore novel therapeutic strategies.

GMP‐compliant manufacturing of biologically active cell‐derived vesicles produced by extrusion technology

Abstract: Extracellular vesicles (EVs) released by a variety of cell types have been shown to act as a natural delivery system for bioactive molecules such as RNAs and proteins. EV therapy holds great promise as a safe and cell-free therapy for many immunological and degenerative diseases. However, translation to clinical application is limited by several factors, including insufficient large-scale manufacturing technologies and low yield. We have developed a novel drug delivery platform technology, BioDrone™, based on cell-derived vesicles (CDVs) produced from diverse cell sources by using a proprietary extrusion process. This extrusion technology generates nanosized vesicles in far greater numbers than naturally obtained EVs. We demonstrate that the CDVs are surrounded by a lipid bilayer membrane with a correct membrane topology. Physical, biochemical and functional characterisation results demonstrate the potential of CDVs to act as effective therapeutics. Umbilical cord mesenchymal stem cell (UCMSC)-derived CDVs exhibit a biological activity that is similar to UCMSCs or UCMSC-derived EVs. Lastly, we present the establishment of a GMP-compliant process to allow the production of a large number of UCMSC-CDVs in a reproducible manner. GMP-compliant manufacturing of CDVs will facilitate the preclinical and clinical evaluation of these emerging therapeutics in anti-inflammatory or regenerative medicine. This study also represents a crucial step in the development of this novel drug delivery platform based on CDVs.

Extracellular Vesicles in Inner Ear Therapies—Pathophysiological, Manufacturing, and Clinical Considerations

Abstract: (1) Background: Sensorineural hearing loss is a common and debilitating condition. To date, comprehensive pharmacologic interventions are not available. The complex and diverse molecular pathology that underlies hearing loss may limit our ability to intervene with small molecules. The current review foccusses on the potential for the use of extracellular vesicles in neurotology. (2) Methods: Narrative literature review. (3) Results: Extracellular vesicles provide an opportunity to modulate a wide range of pathologic and physiologic pathways and can be manufactured under GMP conditions allowing for their application in the human inner ear. The role of inflammation in hearing loss with a focus on cochlear implantation is shown. How extracellular vesicles may provide a therapeutic option for complex inflammatory disorders of the inner ear is discussed. Additionally, manufacturing and regulatory issues that need to be addressed to develop EVs as advanced therapy medicinal product for use in the inner ear are outlined. (4) Conclusion: Given the complexities of inner ear injury, novel therapeutics such as extracellular vesicles could provide a means to modulate inflammation, stress pathways and apoptosis in the inner ear.

SARS-CoV-2 IgG Levels Allow Predicting the Optimal Time Span of Convalescent Plasma Donor Suitability

Abstract: Convalescent plasma (CP) has been in use for the treatment of numerous infectious diseases for more than a century, recently also for coronavirus disease 2019 (COVID-19). A major challenge for this treatment is identifying suitable donors with sufficient levels of functional antibodies and to determine the optimal time span for CP donation. In this retrospective study, we analyzed 189 CP donations of 66 donors regarding anti-SARS-CoV-2 anti-S IgG antibody levels. We found a significant correlation between the semi-quantitative SARS-CoV-2 IgG ratio values and in vitro antibody functionality. A time-to-event analysis allowed us to predict the optimal time span of COVID-19 CP donor suitability. We found that high IgG ratio values, which significantly correlate with high in vitro antibody functionality, were suitable for CP donation for a median of 134 days after the first CP donation. Donors with lower IgG ratios were suitable for a median of 53 days. Our data support plasma collection centers to determine optimal points in time for CP donation by means of widely used semi-quantitative laboratory IgG ratio values.

When the available blood supply mismatches the needs of the patient.

Abstract: BACKGROUND Substantial regional differences in the genetic patterns related to blood group have been observed across different continents. This diversity means that the blood supply, as an essential part of patient care, is increasingly impacted by global migration. Consequently, the Austrian blood donor population does not match the immigrant patient population. This mismatch is likely to result in the formation of alloantibodies to red cell antigens in the chronically transfused. Subsequently, major difficulties in providing compatible blood emerge. MATERIAL AND METHODS The study included patients of African origin (n=290) and Caucasians who represent the Austrian donor population (n=1,017). Genetic typing was performed for up to 69 blood group polymorphisms with a multiplex sequence specific primer-PCR including high frequency antigens and antigens for which antisera are not commercially available. By assessing differences in antigen frequencies between the two populations, and using these data for prophylactic matching, we aim to develop tools to increase the quality of patient care. RESULTS Results indicate various and significant differences (p<0.0001) in antigen frequencies between African patients and the European donor population, especially in the MNS, Duffy, Knops and Rhesus systems. DISCUSSION Our data highlight the importance of matching the donor population to the demographics of the patient population. In addition, it underlines the need to recruit donors of African origin and to focus on the upcoming challenges, such as malaria semi-immunity and a significantly higher rate of infectious disease in this population. It is also recommended to apply extended genetic typing to detect rare blood types, and (cryo)storage of rare blood in national and international rare blood banks. Co-operation with regional blood banks should also be encouraged.

Transcription Factors STAT3 and MYC Are Key Players of Human Platelet Lysate-Induced Cell Proliferation

Abstract: Human platelet lysate (HPL) is an efficient alternative for animal serum supplements, significantly enhancing stromal cell proliferation. However, the molecular mechanism behind this growth-promoting effect remains elusive. The aim of this study was to investigate the effect of HPL on cell cycle gene expression in different human stromal cells and to identify the main key players that mediate HPL’s growth-enhancing effect. RT-qPCR and an antibody array revealed significant upregulation of cell cycle genes in stromal cells cultured in HPL. As HPL is rich in growth factors that are ligands of tyrosine kinase receptor (TKR) pathways, we used TKR inhibitors and could significantly reduce cell proliferation. Genome profiling, RT-qPCR and Western blotting revealed an enhanced expression of the transcription factors signal transducer and activator of transcription 3 (STAT3) and MYC, both known TKR downstream effectors and stimulators of cell proliferation, in response to HPL. In addition, specifically blocking STAT3 resulted in reduced cell proliferation and expression of cell cycle genes. Our data indicate that HPL-enhanced cell proliferation can, at least in part, be explained by the TKR-enhanced expression of STAT3 and MYC, which in turn induce the expression of genes being involved in the promotion and control of the cell cycle.