RESUMO
COVID-19 is a real challenge for the protective immunity. Some people do not respond to vaccination by acquiring an appropriate immunological memory. The risk groups for this particular infection such as the elderly and people with compromised immunity (cancer patients, pregnant women, etc.) have the most serious problems in developing an adequate immune response. Therefore, dendritic cell (DC) vaccines that are loaded ex vivo with SARS-CoV-2 antigens in the optimal conditions are promising for immunization. Lymphocyte effector cells with chimeric antigen receptor (CAR lymphocytes) are currently used mainly as anti-tumor treatment. Before 2020, few studies on the antiviral CAR lymphocytes were reported, but since the outbreak of SARS-CoV-2 the number of such studies has increased. The basis for CARs against SARS-CoV-2 were several virus-specific neutralizing monoclonal antibodies. We propose a similar, but basically novel and more universal approach. The extracellular domain of the immunoglobulin G receptors will be used as the CAR receptor domain. The specificity of the CAR will be determined by the antibodies, which it has bound. Therefore, such CAR lymphocytes are highly universal and have functional activity against any infectious agents that have protective antibodies binding to a foreign surface antigen on the infected cells.
RESUMO
The potential of mesenchymal multipotent (stem) cells (MSC) to modify immune reactions and mediate hematopoiesis boosted great interest for their use in allogeneic hemopoietic stem cell transplantation. Because of MSC production of a wide range of cytokines and growth factors, these cells are included in the therapy of graft-versus-host disease (GVHD). A number of clinical studies have demonstrated safety and efficacy of MSC-based therapy in acute GVHD. Japan and some other countries approved biomedical cell products on the base of allogeneic bone marrow (BM) MSCs as medical agents for acute GVHD treatment. Besides, MSCs may form BM stroma and improve hematopoiesis. Simultaneous transplantation of hematopoietic stem cells and MSCs effectively improved engraftment and prevented GVHD in transplantation of umbilical cord blood and human leukocyte antigens-incompatible BM stem cells. The review presents the analysis of clinical studies of MSCs in allogeneic hematopoietic stem cell transplantation and discusses different approaches for improvement of MSC-based GVHD treatment and prophylaxis.