Host-Pathogen Interactions
Start with the big picture
The lesson follows infection from the first encounter through its possible consequences. Portals such as the skin, respiratory and gastrointestinal tracts, and genitourinary system influence the tissues first exposed and the early immune response. Innate defenses and pattern-recognition receptors initiate protection and inflammation; adaptive T-cell and antibody responses add more targeted defenses. Pathogens may use virulence factors, biofilms, antigenic variation, intracellular survival, or immune evasion to establish infection. The topic also considers superantigens, endotoxin, viral cytopathic effects, and direct or immune-mediated tissue injury. Together, these mechanisms help explain how host defenses and microbial strategies shape disease.
What you'll learn
- Relate common portals of entry to initial tissue tropism and immune encounter.
- Describe key innate defenses and how pattern-recognition receptors activate inflammation.
- Distinguish major adaptive immune responses and their roles in host defense.
- Identify pathogen strategies for colonization, persistence, and immune evasion.
- Explain how microbial factors and immune responses can cause tissue injury.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
