A Comparative Study of the Bone Marrow- and Umbilical Cord-Derived Mesenchymal Stem Cells (MSCs) Efficiency on Generating MSC-Educated Macrophages (MEMs).

BACKGROUND: Mesenchymal stem cells (MSCs) have gained much more attention in cell therapy and regenerative medicine due to their immunosuppressive effects. MSCs have interaction with other immune cells, such as macrophages (MQs). Bone marrow (BM)-derived MSCs can educate MQs toward MSC-educated MQs (MEMs) which possess an anti-inflammatory immunophenotype. Given this and based on the important limitations of BM collection, we hypothesized whether co-culture of MQs with umbilical cord (UC)-derived MSCs can result in the MEM phenotype. METHODS: First, isolated monocytes cultured for five days to obtain M0 MQs. Then, they were co-cultured with either BM- or UC-MSCs under direct and indirect conditions. After three days of co-culture, MEM-specific surface markers, as well as the gene expression of inflammatory and anti-inflammatory cytokines, were evaluated. RESULTS: Surface expression of CD163/CD206, as specific markers for M2 MQs, increased in MEMs after co-culture with BM- and UC-derived MSCs, while CD80/CD86 expression (specific markers for M1 MQs) didn't change significantly. The mRNA expressions of PDL-1 as well as anti-inflammatory cytokines, including IL-6, IL-10, and TGFß also increased in MEMs after co-culture of UC-MSCs compared to control MQs (p <.05), while the expression of IL-12 was significantly decreased (p<.001). CONCLUSIONS: To the best of our knowledge, this study shows for the first time that the co-culture of MQs with UC-derived MSCs efficiently contributes to the generation of MEMs even greater than BM-MSCs; shedding light on the promising potential of UC as an alternative source to educate MQs in vitro.

Computational and Experimental Evaluation of Linker Peptides and Thioredoxin Fusion Tag in CD20-rituximab Specific Interactions.

Background: Overexpression of CD20 protein on the surface of B cells in lymphoma can be targeted by several anti-CD20 molecules. The development of accessible interactive epitopes is more favorable than the full-length transmembrane CD20 in the affinity assessment of anti-CD20 monoclonal antibodies (mAbs). Methods: The sequence of these epitopes was extracted, and the effects of different linker peptides and the location of histidine (His)-tag were computationally analyzed. The impact of thioredoxin (Trx)-tag on the folding of the selected construct and its interaction with rituximab was further investigated. The two final expression cassettes were expressed in Escherichia coli after optimization of culture conditions for incubation temperature, post-induction time, optical density at the induction time, and concentration of the inducer. ELISA evaluated the binding affinity of rituximab towards the recombinant proteins. Results: By homology modeling studies, C-terminal His-tagged structures represented more desirable folded structures. Validation of the models revealed that CD20 extracellular domain linked by the G4S polypeptide had better stereochemical quality and structural compatibility. It was selected due to its more effective interaction with rituximab showing the highest dissociation constant of 5.8E-09M, which improved after the fusion of Trx-tag (7.1E-10M). The most influential parameters in the expression of the two selected proteins were post-induction temperature and optical density at the induction time. Homemade ELISA assays revealed a slightly higher affinity of rituximab towards the Trx-CD20 protein than the CD20/G4S molecule. Conclusions: Experimental in vitro studies confirmed the computationally calculated affinity of rituximab towards the two designed CD20 constructs. Also, the cell-based binding assessment of anti-CD20 mAbs could be substituted by the engineered extracellular domain of human CD20 protein.

COVID-19-related coagulopathy: A review of pathophysiology and pharmaceutical management.

December 2019 will never be forgotten in the history of medicine when an outbreak of pneumonia of unknown etiology in Wuhan, China sooner or later prompted the World Health Organization to issue a public health warning emergency. This is not the first nor will it be the last time that a member of ß-coronaviruses (CoVs) is waging a full-scale war against human health. Notwithstanding the fact that pneumonia is the primary symptom of the novel coronavirus (2019nCoV; designated as SARS-CoV-2), the emergence of severe disease mainly due to the injury of nonpulmonary organs at the shadow of coagulopathy leaves no choice, in some cases, rather than a dreadful death. Multiple casual factors such as inflammation, endothelial dysfunction, platelet and complement activation, renin-angiotensin-aldosterone system derangement, and hypoxemia play a major role in the pathogenesis of coagulopathy in coronavirus disease 2019 (COVID-19) patients. Due to the undeniable role of coagulation dysfunction in the initiation of several complications, assessment of coagulation parameters and the platelet count would be beneficial in early diagnosis and also timely prediction of disease severity. Although low-molecular-weight heparin is considered as the first-line of treatment in COVID-19-associated coagulopathy, several possible therapeutic options have also been proposed for better management of the disease. In conclusion, this review would help us to gain insight into the pathogenesis, clinical manifestation, and laboratory findings associated with COVID-19 coagulopathy and would summarize management strategies to alleviate coagulopathy-related complications.