Which strategy is primarily used by the mucosal immune system to protect against potential infections?

• A. Induction of fever through cytokine release
• B. Activation of cytotoxic T lymphocytes
• C. Secretion of antimicrobial peptides and production of secretory IgA
• D. Formation of granulomas

Answer: (C)

Verified step by step guidance

1. Understand the role of the mucosal immune system: It serves as the first line of defense at mucosal surfaces such as the respiratory, gastrointestinal, and urogenital tracts, where it prevents pathogen entry and colonization.
2. Recognize that the mucosal immune system employs specialized strategies distinct from systemic immunity, focusing on barrier protection and neutralization of pathogens without causing excessive inflammation.
3. Identify that secretion of antimicrobial peptides (AMPs) is a key innate defense mechanism at mucosal surfaces; these peptides can directly kill or inhibit the growth of microbes.
4. Understand that secretory IgA (sIgA) is the predominant antibody class in mucosal secretions; it neutralizes pathogens and toxins by preventing their attachment and entry into epithelial cells.
5. Conclude that the primary protective strategy of the mucosal immune system is the combined action of antimicrobial peptides and secretory IgA, rather than systemic responses like fever induction, cytotoxic T cell activation, or granuloma formation.