PAMPs vs. MAMPs vs. DAMPs

The terms PAMPs, MAMPs, and DAMPs are used to describe different types of molecules that can trigger immune responses. Here’s a comparison of these terms:

1. PAMPs (Pathogen-Associated Molecular Patterns):
   • Definition: PAMPs are molecular patterns that are associated with pathogens, such as bacteria, viruses, fungi, or parasites.
   • Origin: PAMPs are typically conserved structures found on the surfaces of pathogens. These structures are not present in the host organism.
   • Recognition: PAMPs are recognized by pattern recognition receptors (PRRs) on immune cells, initiating an immune response against the invading pathogens.
   • Examples: Examples of PAMPs include bacterial lipopolysaccharides (LPS), viral nucleic acids (e.g., double-stranded RNA), fungal cell wall components (e.g., β-glucans), and parasite-specific molecules.
2. MAMPs (Microbe-Associated Molecular Patterns):
   • Definition: MAMPs are essentially the same as PAMPs but may be used more broadly to include molecular patterns associated with various microbes, not just pathogens.
   • Usage: The term “MAMPs” is sometimes preferred to acknowledge that not all microbes are pathogenic, and the immune system may respond to a broader range of microorganisms, including commensals and non-pathogenic microbes.
   • Recognition: MAMPs are recognized by PRRs on immune cells, triggering immune responses against microbes.
3. DAMPs (Damage-Associated Molecular Patterns):
   • Definition: DAMPs are molecular patterns that are associated with cellular damage or stress rather than with invading pathogens.
   • Origin: DAMPs are molecules that are typically found within host cells and are released or exposed when cells are damaged or stressed.
   • Recognition: DAMPs are recognized by PRRs, signaling the immune system that there is cellular damage and prompting an immune response to address tissue injury.
   • Examples: Examples of DAMPs include molecules like HMGB1 (High Mobility Group Box 1), ATP, and heat-shock proteins that are released from damaged or dying cells.

Summary:

• PAMPs: Associated with pathogens, recognized by PRRs, and trigger immune responses against invading microorganisms.
• MAMPs: Essentially the same as PAMPs but used more broadly to include molecular patterns associated with various microbes, not just pathogens.
• DAMPs: Associated with cellular damage or stress, recognized by PRRs, and signal the immune system to respond to tissue injury or damage.

Next Topic: Molecular Patterns Recognized by Innate Immune Receptors

Source: ChatGPT response prompted and edited by Joel Graff.

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