Cellular Therapy: The Hope for Covid-19.

Coronaviruses (CoVs) are a group of very diverse viruses that cause a broad spectrum of diseases from mild to severe enteric, respiratory, systemic diseases, and common cold or pneumonia among humans and animals. This virus is associated with Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS), and lung disease that lead to Acute Respiratory Distress Syndrome (ARDS). In December 2019, researchers identified a novel coronavirus type, called Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2), which was associated with symptoms of high fever, dry cough, headache, diarrhea, and reduction of White Blood Cells (WBC). Coronavirus-associated acute respiratory disease was named Coronavirus Disease 19 (COVID-19). No proven treatment has been discovered for COVID-19 so far, but researchers are trying to find the best effective way to treat this disease. Therefore, therapeutic strategies that facilitate the recovery of COVID-19 patients and reduce life-threatening complications are urgently needed now. Today, Mesenchymal Stem Cells (MSCs) and their secretion are utilized as one of the most applied tools to treat various diseases such as inflammation and cancer. MSC-derived vesicles are rich in various growth factors, cytokines, and interleukins that are produced and secreted under different physiological or pathological conditions. These vesicles were considered a suitable and effective tool in regeneration medicine because of their high power in repairing damaged tissues and modulating immune responses. Recently, evidence has shown MSC-derived vesicles through reduced expression of pro-inflammatory cytokines could improve damaged tissues in COVID-19 patients. In addition to MSCs and MSC-derived exosomes, Natural Killer (NK) cells, T cells, and platelet lysates were used against viral infection. In this review, we tried to provide an overview of MSC secretion and immune cells for COVID-19 therapy.