Innate Immunity: Physical and Mechanical Barriers
DOI:
https://doi.org/10.33687/ricosbiol.04.04.121Keywords:
Innate immunity, physical barriers, mechanical barriers, skin, mucous membranes, alveolar macrophages, SALT, mucosal-associated lymphoid tissue, antimicrobial peptidesAbstract
Innate immunity constitutes the first line of host defense against invading pathogens (Turvey & Broide, 2010). Among its components, physical and mechanical barriers play a fundamental role by preventing microbial entry, colonization, and dissemination. This educational note provides a comprehensive overview of these barriers across different anatomical sites, including the skin, mucous membranes, respiratory tract, gastrointestinal tract, genitourinary tract, and eyes. It also details associated chemical factors (e.g., lysozyme, lactoferrin, gastric juice, bacteriocins) and cellular elements such as Langerhans cells, M cells, and alveolar macrophages (Abbas et al., 2020; Gallo & Hooper, 2012). The note emphasizes the synergistic action of physical, mechanical, and chemical mechanisms that together form an effective surveillance system. Understanding these barriers is essential for appreciating how the body resists infection before adaptive immunity is engaged.
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References
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Data Availability Statement
As a narrative review, this manuscript synthesizes and discusses previously published data. No novel datasets were created or analyzed. All data referenced herein can be found in the original research articles cited in the reference list.
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