Innate immunity Flashcards
Name and describe the three main categories of innate immune barriers.
The three main categories of innate immune barriers are anatomical (mechanical, chemical, and biological), humoral (including the complement system, coagulation, and antimicrobial proteins), and cellular (involving various immune cells like macrophages, eosinophils, neutrophils, and natural killer cells).
How does cellular communication contribute to generating appropriate immune responses?
Cellular communication is crucial for coordinating immune responses. It helps immune cells exchange information, activate necessary pathways, and recruit appropriate immune cells to the site of infection.
What is the role of pattern recognition in innate immunity?
Pattern recognition in innate immunity involves specific host cells recognizing non-self through receptors called Pattern Recognition Receptors (PRRs), which recognize Pathogen Associated Molecular Patterns (PAMPs).
How do cells of the innate immune system recognize pathogens?
Cells of the innate immune system, such as macrophages and dendritic cells (DCs), recognize pathogens through Pattern Recognition Receptors (PRRs), which are expressed on their surfaces. These receptors specifically recognize Pathogen Associated Molecular Patterns (PAMPs).
Why are PRRs referred to as “pattern recognition receptors”?
PRRs are called “pattern recognition receptors” because they identify repeating patterns of molecular structures on the surfaces of microorganisms, such as viruses with double-stranded RNA, bacterial DNA with unmethylated CpG repeats, and specific lipopolysaccharides on bacterial cell surfaces.
Why are PAMPs ideal for innate immune recognition?
AMPs (Pathogen Associated Molecular Patterns) are ideal for innate immune recognition because they are produced only by microbes and not by host cells. They are invariant, allowing a limited number of PRRs to recognize a wide range of microbial infections. PAMPs are usually essential for microbial survival, and their loss or mutation can lead to reduced fitness, making it harder for mutants to evade detection.
Explain the concept of danger-associated molecular patterns (DAMPs) in relation to innate immunity.
Danger-associated molecular patterns (DAMPs) are molecules released by damaged or stressed host cells. They can activate Pattern Recognition Receptors (PRRs) and trigger immune responses, even in the absence of infections. DAMPs serve as signals of tissue damage and contribute to the initiation of inflammation.
How can Toll-like receptors (TLRs) be exploited for immunotherapy?
Toll-like receptors (TLRs) can be exploited for immunotherapy by using TLR agonists to promote inflammation or enhance anti-tumor responses. TLR agonists can be used to stimulate the immune system to recognize and attack tumors. Conversely, TLR antagonists can be used to dampen an overactive immune response in cases of excessive inflammation.
Provide an example of an FDA-approved TLR agonist.
Imiquimod is an FDA-approved TLR7 agonist that is used topically for treating skin conditions such as lentigo maligna (a form of melanoma in situ) and genital warts. It stimulates the immune response through TLR7 activation.
How was TLR7 targeted using imiquimod in the context of lentigo maligna treatment?
Imiquimod, a TLR7 agonist, was applied topically to treat lentigo maligna (in situ melanoma). The treatment was effective in an 80-year-old patient with an extensive LM lesion on the face. Imiquimod treatment led to a complete clinical response, and the patient remained free from recurrence one year after treatment.
How does innate immunity distinguish between self and non-self using pattern recognition receptors?
Innate immunity distinguishes between self and non-self through Pattern Recognition Receptors (PRRs) that recognize Pathogen Associated Molecular Patterns (PAMPs) present on microbes. Since PAMPs are produced only by microbes and not by host cells, this allows the immune system to distinguish between self and non-self entities.
What is the role of danger-associated molecular patterns (DAMPs) in immune responses?
Danger-associated molecular patterns (DAMPs) are released by damaged or stressed host cells and signal tissue damage. They activate Pattern Recognition Receptors (PRRs), triggering immune responses. DAMPs contribute to the initiation of inflammation and immune reactions, even in the absence of infections.
