Question

Pathogens may try to sabotage phagocytosis. Give some examples of how they may do this.

a) Pathogens may release toxic chemicals to attract phagocytes.
b) Pathogens may block phagocyte receptors.
c) Pathogens may produce decoy PAMPs to confuse phagocytes.
d) Pathogens are incapable of sabotaging phagocytosis.

Answer 1

Pathogens use various methods to sabotage phagocytosis, such as protective capsules, secretion of toxins, and proteases that degrade antibodies. Additionally, alterations to pathogen surface proteins can prevent effective immune response, showcasing the evolutionary battle between pathogen evasion and host immunity.

Step-by-step explanation:

Pathogens have developed numerous methods to sabotage phagocytosis, thereby evading the immune system's defenses. For instance, Streptococcus pneumoniae produces a protective capsule that inhibits phagocytes from engulfing it. In contrast, Staphylococcus aureus secretes leukocidin, a toxin that kills phagocytes post-engulfment. Additionally, Mycobacterium tuberculosis uses mycolic acid in its cell wall to resist the killing mechanisms of phagolysosomes after being phagocytosed. Viral pathogens like HIV infect T cells and deplete them, significantly weakening the adaptive immune response.

Other pathogens secrete proteases that degrade antibodies, stifling the initiation of phagocytosis. Similarly, some bacteria produce M protein within their fimbriae to block the binding of complement molecules, which aid in the opsonization process essential for phagocytosis. These adaptations reflect the ongoing evolutionary arms race between pathogens and the immune response of the host organism.