Final answer:
Pathogens can escape or subvert the immune defenses through various mechanisms such as the formation of capsules, production of toxins, and disabling immune cells.
Step-by-step explanation:
Pathogens have evolved various strategies to escape or subvert the immune defenses. Some examples include:
- Formation of capsules: Some bacteria, like Streptococcus pneumoniae, surround themselves with a capsule that inhibits phagocytes from engulfing them and displaying antigens to the adaptive immune system.
- Production of toxins: Staphylococcus aureus synthesizes a toxin called leukocidin that kills phagocytes after they engulf the bacterium.
- Disabling immune cells: HIV infects T cells, gradually depleting their numbers and inhibiting the adaptive immune system's capacity to generate sufficient responses to infection or tumors.