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Chemokines are a large family of small cytokines and generally have low molecular weight ranging from 7 to 15kDa. Chemokines and their receptors are able to control the migration and residence of all immune cells. Some chemokines are considered pro-inflammatory, and their release can be induced during an immune response at a site of infection, while others are considered homeostatic and are involved in controlling of cells migration during tissue development or maintenance. The physiologic importance of this family of mediators is resulting from their specificity - members of the chemokine family induce recruitment of well-defined leukocyte subsets. There are two major chemokine sub-families based upon cysteine residues position: CXC and CC. As a general rule, members of the CXC chemokines are chemotactic for neutrophils, and CC chemokines are chemotactic for monocytes and sub-set of lymphocytes, although there are some exceptions. This review discusses the potential role of chemokines in inflammation focusing on the two best-characterized chemokines: monocyte chemoattractant protein-1, a CC chemokine, and interleukin-8, a member of the CXC chemokine sub-family. [ABSTRACT FROM AUTHOR]

Objective: To establish the method of isolation and culture of human glioblastoma neurospheres, and the purification of their stem cells, followed by the process of obtaining tumor subspheres, immunophenotypically characterizing this clonogenic set. Methods: Through the processing of glioblastoma samples (n=3), the following strategy of action was adopted: (i) establish primary culture of glioblastoma; (ii) isolation and culture of tumor neurospheres; (iii) purify cells that initiate tumors (CD133+) by magnetic separation system (MACS); (iv) obtain tumor subspheres; (v) study the expression of the markers nestin, CD133, and GFAP. Results: The study successfully described the process of isolation and culture of glioblastoma subspheres, which consist of a number of clonogenic cells immunophenotypically characterized as neural, which are able to initiate tumor formation. Conclusion: These findings may contribute to a better understanding of the process of gliomagenesis. [ABSTRACT FROM AUTHOR]

Objective: To compare human mesenchymal stem cells obtained from reusable and disposable filters and to characterize them according to the criteria of the International Society of Cellular Therapy. Methods: Human mesenchymal stem cells were isolated from bone marrow collection reusable sets and compared with those obtained from disposable sets by washing the filters with cell culture media. The isolated cells were characterized according to the criteria of the International Society of Cellular Therapy using flow cytometry, differentiation in vitro, and cytochemistry techniques. Results: Samples were obtained from disposable (n=3) and from reusable collection sets (n=3). All samples obtained from bone marrow disposable sets successfully produced mesenchymal stem cells. All bone marrow derived mesenchymal stem cells were characterized and fulfilled the criteria established by International Society of Cellular Therapy. Conclusion: This study showed that mesenchymal stem cells can also be obtained from reusable collection sets (which are still used in several centers around the world) to be employed in research as an alternative and ethical source [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to evaluate the effect of the labeling of umbilical cord vein derived mesenchymal stem cells with superparamagnetic iron oxide nanoparticles coated with dextran and complexed to a non-viral transfector agent transfector poly-L-lysine. Methods: The labeling of mesenchymal stem cells was performed using the superparamagnetic iron oxide nanoparticles/dextran complexed and not complexed to poly-L-lysine. Superparamagnetic iron oxide nanoparticles/dextran was incubated with poly-L-lysine in an ultrasonic sonicator at 37°C for 10 minutes for complex formation superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine by electrostatic interaction. Then, the mesenchymal stem cells were incubated overnight with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran. After the incubation period the mesenchymal stem cells were evaluated by internalization of the complex superparamagnetic iron oxide nanoparticles/dextran/poly- L-lysine and superparamagnetic iron oxide nanoparticles/dextran by Prussian Blue stain. Cellular viability of labeled mesenchymal stem cells was evaluated by cellular proliferation assay using 5,6-carboxyfluorescein- succinimidyl ester method and apoptosis detection by Annexin V- Propidium Iodide assay. Results: mesenchymal stem cells labeled with superparamagnetic iron oxide nanoparticles/ dextran without poly-L-lysine not internalized efficiently the superparamagnetic iron oxide nanoparticles due to its low presence detected within cells. Mesenchymal stem cells labeled with the complex superparamagnetic iron oxide nanoparticles/dextran/poly- L-lysine efficiently internalized the superparamagnetic iron oxide nanoparticles due to greater presence in the cells interior. The viability and apoptosis assays demonstrated that the mesenchymal stem cells labeled and not labeled respectively with the superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine continue to proliferate over seven days and the percentage of cells in early or late apoptosis is low compared to the percentage of live cells over the three days. Conclusion: Our results showed that the use of poly-L-lysine complexed with superparamagnetic iron oxide nanoparticles/dextran provides better internalization of these superparamagnetic iron oxide nanoparticles in mesenchymal stem cells Thus, we demonstrated that this type of labeling is not cytotoxic to the mesenchymal stem cells, since the viability and apoptosis assays showed that the cells remain alive and proliferating. The efficiency of this type of labeling in mesenchymal stem cells can provide non-invasive methods for monitoring these cells in vivo. [ABSTRACT FROM AUTHOR]

The objective of this study was to highlight the global scientific effort to fight the SARS-CoV-2, addressing the preliminary results of passive immunization through convalescent plasma. We performed a search at the major databases of interventional clinical trial protocols about the transfusion of convalescent plasma in patients with COVID-19, as well as, published articles (n≥25), using the following search strategy: [(COVID-19 OR SARS-CoV-2 OR nCoV-2019) AND (Convalescent plasma OR Plasma exchange) AND (Treatment OR Therapy)]. A total of 24 interventional clinical trial protocols (advanced in phases II-III, III, and IV) were included in this review, as well as three studies that had enough outcomes to evaluate the efficacy of convalescent plasma therapy for patients with COVID-19. All interventional clinical trial protocols applied approximately 500mL of convalescent plasma (from single or more donations) in hospitalized patients, mainly in patients with severe disease associated with standard therapy for COVID-19, and compared to placebo or standard therapy plus specific drugs. Most of interventional clinical trial protocols are multicenter, and the phase IV studies are recruiting at intercontinental centers of North America, Oceania, Europe, but most are recruiting center inside their own county. The three studies published reported similar approach of convalescent plasma intervention with decrease in length of stay, mortality, with less than 4% of adverse events, mainly for treating critical cases with life-threatening disease. All advanced clinical trials focused on convalescent plasma therapy in patients with COVID-19 hospitalized in severe conditions, and the preliminary results provide strong evidence for therapy for the COVID-19 patients.

Chemokines are a large family of small cytokines and generally have low molecular weight ranging from 7 to 15kDa. Chemokines and their receptors are able to control the migration and residence of all immune cells. Some chemokines are considered pro-inflammatory, and their release can be induced during an immune response at a site of infection, while others are considered homeostatic and are involved in controlling of cells migration during tissue development or maintenance. The physiologic importance of this family of mediators is resulting from their specificity - members of the chemokine family induce recruitment of well-defined leukocyte subsets. There are two major chemokine sub-families based upon cysteine residues position: CXC and CC. As a general rule, members of the CXC chemokines are chemotactic for neutrophils, and CC chemokines are chemotactic for monocytes and sub-set of lymphocytes, although there are some exceptions. This review discusses the potential role of chemokines in inflammation focusing on the two best-characterized chemokines: monocyte chemoattractant protein-1, a CC chemokine, and interleukin-8, a member of the CXC chemokine sub-family.

Human interleukin 17 was first described in 1995 as a new cytokine produced primarily by activated T CD4+ cells that stimulate the secretion of IL-6 and IL-8 by human fibroblasts, besides increasing the expression of ICAM-1. Various authors have reported that IL-17A has a role in the protection of organisms against extracellular bacteria and fungi due to the capacity of IL-17A to recruit neutrophils to the areas of infection, evidencing a pathological role in various models of autoimmune diseases, such as experimental autoimmune encephalitis and arthritis. The participation of IL-17A has also been described in the acute rejection of organ transplants and graft versus host disease. However, the greatest revolution in research with IL-17 happened in 2000, when it was proposed that IL-17 cannot be classified as Th1 or Th2, but rather, simply as a new lineage of IL-17-producing T-cells. These findings modified the previously established Th1/Th2 paradigm, leading to the definition of the CD3+ CD4+ Th17 cellular subtype and establishment of a new model to explain the origin of various immune events, as well as its implication in the graft versus host disease that is discussed in depth in this article.

Objective: To compare human mesenchymal stem cells obtained from reusable and disposable filters and to characterize them according to the criteria of the International Society of Cellular Therapy., Methods: Human mesenchymal stem cells were isolated from bone marrow collection reusable sets and compared with those obtained from disposable sets by washing the filters with cell culture media. The isolated cells were characterized according to the criteria of the International Society of Cellular Therapy using flow cytometry, differentiation in vitro, and cytochemistry techniques., Results: Samples were obtained from disposable (n=3) and from reusable collection sets (n=3). All samples obtained from bone marrow disposable sets successfully produced mesenchymal stem cells. All bone marrow derived mesenchymal stem cells were characterized and fulfilled the criteria established by International Society of Cellular Therapy., Conclusion: This study showed that mesenchymal stem cells can also be obtained from reusable collection sets (which are still used in several centers around the world) to be employed in research as an alternative and ethical source.

Objective: The objective of this study was to evaluate the effect of the labeling of umbilical cord vein derived mesenchymal stem cells with superparamagnetic iron oxide nanoparticles coated with dextran and complexed to a non-viral transfector agent transfector poly-L-lysine., Methods: The labeling of mesenchymal stem cells was performed using the superparamagnetic iron oxide nanoparticles/dextran complexed and not complexed to poly-L-lysine. Superparamagnetic iron oxide nanoparticles/dextran was incubated with poly-L-lysine in an ultrasonic sonicator at 37°C for 10 minutes for complex formation superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine by electrostatic interaction. Then, the mesenchymal stem cells were incubated overnight with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran. After the incubation period the mesenchymal stem cells were evaluated by internalization of the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran by Prussian Blue stain. Cellular viability of labeled mesenchymal stem cells was evaluated by cellular proliferation assay using 5,6-carboxy-fluorescein-succinimidyl ester method and apoptosis detection by Annexin V- Propidium Iodide assay., Results: mesenchymal stem cells labeled with superparamagnetic iron oxide nanoparticles/dextran without poly-L-lysine not internalized efficiently the superparamagnetic iron oxide nanoparticles due to its low presence detected within cells. Mesenchymal stem cells labeled with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine efficiently internalized the superparamagnetic iron oxide nanoparticles due to greater presence in the cells interior. The viability and apoptosis assays demonstrated that the mesenchymal stem cells labeled and not labeled respectively with the superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine continue to proliferate over seven days and the percentage of cells in early or late apoptosis is low compared to the percentage of live cells over the three days., Conclusion: Our results showed that the use of poly-L-lysine complexed with superparamagnetic iron oxide nanoparticles/dextran provides better internalization of these superparamagnetic iron oxide nanoparticles in mesenchymal stem cells Thus, we demonstrated that this type of labeling is not cytotoxic to the mesenchymal stem cells, since the viability and apoptosis assays showed that the cells remain alive and proliferating. The efficiency of this type of labeling in mesenchymal stem cells can provide non-invasive methods for monitoring these cells in vivo.

The major complications after bone marrow transplant are related to opportunistic infections or to graft-versus-host disease. Today, there is a wealth of information associated with bone marrow transplantation and new treatment approaches have been proposed to overcome these complications. Behind these new therapies, such as adoptive transfer of T cells or mesenchymal stem cell infusions, there is significant basic research to support these clinical advances. Most of this knowledge has derived from the development of animal models and intense laboratory work to test and confirm hypotheses. There is no doubt that basic research is still necessary to better understand the basis for clinical outcome improvements.

Mesenchymal stem cells represent an adult population of nonhematopoietic cells, which can differentiate into a variety of cell types such as osteocytes, chondrocytes, adipocytes, and myocytes. They display immunomodulatory properties that have led to the consideration of their use for the inhibition of immune responses. In this context, mesenchymal stem cells efficiently inhibit maturation, cytokine production, and the T cell stimulatory capacity of dendritic cells. They also can impair proliferation, cytokine secretion, and cytotoxic potential of T lymphocytes. Moreover, mesenchymal stem cells are able to inhibit the differentiation of B cells to plasma cells by inhibiting their capacity to produce antibodies. A variety of animal models confirm the immunomodulatory properties of mesenchymal stem cells. Clinical studies including patients with severe acute graft-versus-host disease have revealed that the administration of mesenchymal stem cells results in significant clinical responses. Therefore, mesenchymal stem cells improve acute graft-versus-host disease and represent a promising candidate for the prevention and treatment of immune-mediated diseases, due to their immunomodulatory capability and their low immunogenicity.