Immune Checkpoint Regulators: A New Era Toward Promising Cancer Therapy.

During the last century, our battle against cancer has been inaugurated upon three main approaches; surgery, radiation and chemotherapy. The latest findings on the effectiveness of immunotherapy in cancer management offer a ray of hope after decades of research and studies on the best treatment methods. Immunotherapy has proven effective in the surveillance and destruction of cancer- causing cells, demonstrating its ability to suppress cancer through controlling the wellestablished immune-editing process. Immuno-editing is a process that comprises three principal elements; elimination, equilibrium, and escape, and is paramount to the comprehension of checkpoint inhibition. Cancer cells employ various approaches to evade the elimination step leading to its immune- escape. The escape mechanism encompasses the up-regulation of negative co-signals that block successful activation of cancer-eradicating immune cells, developing cytokine background that favors the immunosuppressive tumor microenvironment (TME), or dropping the expression of tumor- specific proteins known as neo-antigens, therefore reducing the immunogenic activity against cancer cells. Today, checkpoint inhibitors are considered as a primary approach in our fight against cancer. Strategies targeting the inhibitory roles of checkpoint inhibitors have been shown effective against different cancer types and stages, and some already gained the FDA's approval. This review seeks to comprehensively cover the historical background as well as the most recent updates for the role of immune checkpoint regulators in the maintenance of immune homeostatic balance as well as keeping the tumorigenic cells in check.

Respiratory syncytial virus and human metapneumovirus in severe lower respiratory tract infections in children under two.

INTRODUCTION: Viruses are the most important causative agents of acute lower respiratory tract infections (ALRTIs), ranked as the second leading cause of death and the primary cause of hospitalization in children. Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are among the commonest viral causes of severe ALRTI. In this study, we aimed to study the burden of both RSV and hMPV in causing severe ALRTI in children younger than two years of age admitted to the pediatric intensive care unit (PICU). METHODOLOGY: Nasopharyngeal swabs were collected from children admitted to the PICU with a diagnosis of community-acquired ALRTI who were two years of age or younger. Real-time polymerase chain reaction (RT-PCR) was used to test for RSV and hMPV. RESULTS: A total of 127 swabs were screened for RSV and hMPV, of which 49.6% were negative for RSV and hMPV, 46.4% were positive for RSV, and 3.9% were positive for hMPV. With respect to RSV, the mean age of cases (4.01 ± 5.05) and the monthly distribution (mainly January) were the most important risk factors. There were no statistically significant differences between the RSV group and control group regarding duration of hospital stay, mechanical ventilation need or duration, and underlying chronic conditions. CONCLUSIONS: RSV is important viral cause of severe ALRTIs in children younger than two years of age during this study period; hMPV played a minor role.