ABSTRACT
Elucidating the role of probiotic bacteria in health and disease perhaps constitutes one of the most exciting and fastest growing fields in medicine as we uncover the beneficial roles of these bacteria in many disease processes including cancer. We and others have reported previously that probiotic bacteria play a significant role in the activation of many cells including the cancer fighting natural killer (NK) cells. NK cells are the key immune effectors which control tumor growth and metastasis due to their ability to mediate direct cytotoxicity and/or differentiation of cancer stem cells/undifferentiated tumors through secreted and membrane bound interferon-gamma and tumor necrosis factor-alpha. In this review, we present an overview of recent studies from our laboratory and those of the others on their beneficial effects on immune cell function in particular on NK cells. In addition, we also highlight the current understanding of the role of probiotics in enhancement of the effectiveness of cancer therapeutics. Moreover, we discuss the functional impairment of cancer patients' NK cells and the role of probiotics in reversal of such functional impairment. NK cell-based immuno-therapies in combination with well-selected strains of probiotic bacteria may probably represent one of the best adjunct therapeutic approaches to prevent and treat cancer in the future.
Subject(s)
Killer Cells, Natural/cytology , Lymphocyte Activation , Neoplasms , Probiotics , Humans , Neoplasms/therapy , Probiotics/therapeutic useABSTRACT
Coronavirus-induced disease-2019 (COVID-19) continues to cause significant morbidity and mortality worldwide. While studies on SARS-CoV-2 effects on immune cell function continue to progress, we know very little about the significance of depletion of key immune effectors by the virus in the mortality and morbidity of the disease. This commentary outlines what is the reported literature thus far on the effect of virus on NK cells known to kill virally infected cells. It also underscores the necessity for the future comprehensive studies of NK cells in SARS-CoV-2 infected individuals and animal models to better understand the role and significance of reported NK cell depletion and functional inactivation in disease morbidity and mortality, in hope to design effective therapeutic interventions for the disease.
Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Coronavirus Infections/therapy , Immunotherapy/methods , Killer Cells, Natural/immunology , Killer Cells, Natural/metabolism , Pneumonia, Viral/immunology , Pneumonia, Viral/therapy , Adult , Aged , Animals , CD8-Positive T-Lymphocytes/immunology , COVID-19 , Coronavirus Infections/blood , Coronavirus Infections/virology , Cytokines/blood , Disease Progression , Female , Humans , Male , Middle Aged , Middle East Respiratory Syndrome Coronavirus/immunology , NK Cell Lectin-Like Receptor Subfamily C/metabolism , Neutrophils/immunology , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/virology , SARS-CoV-2ABSTRACT
Coronavirus disease 2019 (COVID-19) poses a great public health challenge worldwide. While studies on the effects of SARS-CoV-2 on immune cell function continue to progress, we know very little about the significance of depletion of key immune effectors by the virus in the mortality and morbidity of the disease. This commentary reviews what is known thus far about the effects of the virus on natural killer (NK) cells, the major cell type responsible for the destruction and removal of virally infected cells. It also highlights the necessity of comprehensive studies of NK cells in COVID-19 patients and animal models to better understand the role and significance of reported NK depletion and functional inactivation in disease morbidity and mortality, in the hopes of designing effective therapeutic interventions for the disease.