COVID-19の炎症とC5a-C5aR1軸の活性化との関連

Overview

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...

An inflammatory response is a localized, nonspecific immune reaction that occurs when a tissue is injured. It is characterized by redness, swelling, heat, and pain, which are commonly called the cardinal signs and symptoms of inflammation. Inflammation can sometimes result in a loss of function.
Inflammation can be triggered by various stimuli, such as impact, abrasion, chemical irritation, infections, and extreme hot or cold temperatures. These can damage cells and connective tissue fibers,...

The inflammatory response is the body's defense against infection, injury, or irritation from bacteria, trauma, toxins, or heat. Inflammation helps locate and destroy pathogens and remove damaged tissue elements to heal the body. During this initial phase, fluid, blood products, and nutrients migrate to the injured area, resulting in redness, heat, swelling, ache, and loss of function. Moreover, signs of systemic inflammation include fever, increased WBC count, malaise, anorexia, nausea,...

When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...

The immune system's inflammatory response destroys the invading pathogen, permitting the tissue to heal. The changes during the cellular and vascular stages allow exudate formation at the site of inflammation. The inflammatory exudate released from the wound has high protein content and a specific gravity above 1.020.
The typical wound exudate is odorless, transparent, straw-colored, thin, and watery. Exudate, however, can differ depending on the state of wound healing. Likewise, the...