👉
Infection biology focuses on the mechanisms by which pathogens, such as bacteria, viruses, fungi, and parasites, invade, colonize, and cause disease within a host organism. The immune system, comprising various teams of cells and molecules, plays a crucial role in defending against these invaders. The
innate immune system
is the first line of defense, consisting of physical barriers like skin and mucous membranes, as well as cells such as neutrophils, macrophages, and natural killer (NK) cells that can recognize and eliminate pathogens without prior exposure. The
adaptive immune system
, on the other hand, is more specific and develops over time after initial exposure to a pathogen. It involves T cells and B cells, which can remember specific pathogens and mount a faster, more targeted response upon subsequent encounters. Infections occur when these defenses are overwhelmed or circumvented by the pathogen, leading to disease. Understanding the interactions between these immune teams is essential for developing effective treatments and vaccines against infectious diseases.