No Respite from Toxins
The human immune system is actually two systems developed at different points in human evolution. White blood cells of the more primitive innate system, like neutrophils and macrophages, form the first line of defense against disease. They swarm to the injury to engulf and destroy bacteria with toxic molecules and biochemicals. Because these same molecules and chemicals are also toxic to nearby human cells, the innate response is normally shut down quickly by the onset of the more time-consuming, precise and thorough adaptive immune system.
This second system pumps out an endless variety of immune cells on the hope that one or more will be the right shape to link up with, and become activated by, any invader encountered. When one of those immune cells, called lymphocytes, recognizes a bacterium or virus presented by the innate system, that lymphocyte expands into army of clones specifically designed to attack the invader at hand. Unfortunately, lymphocytes too are capable of mistakenly destroying human cells. Thus, they have developed quality control mechanisms where they can choose to stop expanding into an army (anergy) or to commit suicide (apoptosis).
The PNAS study offers new evidence that an overwhelming wave of biochemical signals created by the innate response after massive trauma can mistakenly trigger anergy and apoptosis, especially in T cell lymphocytes, shutting down the adaptive response before it can begin. Without the normal transition, the innate system continues to pump out toxic chemicals (cytokines) and molecules (free radicals) that tear at organs until they fail.
The goal of the current study was to identify the few genes and prote
Source:University of Rochester Medical Center