Which component of the innate immune response is primarily responsible for creating an inhospitable environment for pathogens?

The complement system is the main innate component that makes the environment hostile to microbes. When activated, it tags pathogens for destruction, attracts immune cells, and builds membrane attack complexes that puncture bacterial or viral membranes. This series of reactions turns the surrounding area into a toxic, lytic zone that kills or disables the invader. For example, when a bacterium enters the bloodstream, complement proteins coat it, recruit neutrophils, and then form a pore that bursts the bacterium’s cell wall, making the blood inhospitable to the pathogen.