W2-5 Innate immunity

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Which of the following best describes innate immunity?

It is acquired through exposure to pathogens

It provides immediate, non-specific defense against infections (correct)

It is specific to particular pathogens

It involves memory cells and antibodies

What is the main function of natural barriers to infection?

To produce antibodies

To recognize specific pathogens

To activate memory cells

To prevent the entry of pathogens into the body (correct)

Which type of cells are key cellular components of innate immunity?

Helper and killer T cells

Macrophages and neutrophils (correct)

T cells and B cells

Memory cells and plasma cells

What is the role of phagocytes in pathogen recognition?

Recognizing specific antigens on pathogens Signup and view all the answers

What is the process of neutrophil recruitment and activation called?

Chemotaxis Signup and view all the answers

Which pathway involves the activation of NF-B in innate immunity?

Toll-like receptor pathway Signup and view all the answers

What is the main physical barrier in the skin as part of the innate immunity?

Tight junctions Signup and view all the answers

Which of the following is NOT a component of mucus and physical defense in the respiratory tract as part of innate immunity?

Presence of resident bacteria Signup and view all the answers

Which enzyme is responsible for generating reactive oxygen species (ROS) for phagocyte killing?

Phagocyte oxidase Signup and view all the answers

Which type of interferon is primarily involved in antiviral defense?

IFN- Signup and view all the answers

Which type of cells express Killer Inhibition Receptor (KIR) as part of their innate killing function?

NK cells Signup and view all the answers

What is the main function of Type III interferons (IFN-) in innate immunity?

Inhibition of viral replication Signup and view all the answers

Which protein measures the killing capacity by reactive oxygen species (ROS) in phagocytes?

NBT (Nitro Blue Tetrazolium) Signup and view all the answers

What is the role of Tamm-Horsfall protein (THP) in the genitourinary tract as part of innate immunity?

Antimicrobial and immunomodulatory actions Signup and view all the answers

Which cytokine activates the natural killer (NK) cells as part of their innate killing function?

IL-12 Signup and view all the answers

What is the main function of epithelial cells in the context of innate immunity?

First line of defense Signup and view all the answers

Which protein is NOT associated with the complement system as part of innate effector functions?

Interferon- Signup and view all the answers

Which enzyme deficiency is clinically significant in Chronic Granulomatous Disease?

NADPH oxidase Signup and view all the answers

Which of the following is NOT a cellular component of innate immunity?

B lymphocytes Signup and view all the answers

What is the process called when phagocytes engulf and kill pathogens?

Phagocytosis Signup and view all the answers

Which signaling pathway is involved in the activation of NF-κB in innate immunity?

MAPK pathway Signup and view all the answers

What is the primary function of natural killer (NK) cells in innate immunity?

Cytotoxicity Signup and view all the answers

Which enzyme deficiency is clinically significant in Chronic Granulomatous Disease (CGD)?

NADPH oxidase Signup and view all the answers

What is the main function of Type I interferons (IFN-α and IFN-β) in innate immunity?

Induction of antiviral state in cells Signup and view all the answers

What is the main function of the innate immune system in response to pathogens?

To recognize and activate adaptive immunity Signup and view all the answers

Which enzyme is responsible for the conversion of oxygen to the super oxide radical and the formation of hydrogen peroxide and singlet oxygen in phagocytes?

Nicotinamide-adenine phosphate (NADPH) oxidase Signup and view all the answers

Which of the following is a mechanism of action by which natural killer (NK) cells kill infected and abnormal host cells?

Expression of FasL and binding to Fas Signup and view all the answers

What is the role of CD16 in both NK cells and other immune cells such as neutrophils and macrophages?

Mediating antibody mediated cellular cytotoxicity (ADCC) Signup and view all the answers

What is the function of killer inhibition receptors (KIR) in relation to NK cell action?

Binding to MHC-1 on normal host cells to protect them from NK action Signup and view all the answers

What is the main source of energy for resting phagocytes, except for alveolar macrophages?

Anaerobic glycolysis Signup and view all the answers

What is the enzyme required for the shift in metabolic pathway of phagocytes to the greater energy efficient hexose monophosphate shunt?

Glucose-6-phosphate dehydrogenase Signup and view all the answers

Which molecule is responsible for ensuring that normal host cells are protected from NK action?

Killer inhibition receptors (KIR) Signup and view all the answers

What is the main role of cytokines in relation to innate immunity?

Signal and regulate immune responses Signup and view all the answers

What is the function of nitroblue tetrazolium (NBT) score in relation to phagocytes?

Measure intracellular killing capacity by reactive oxygen species (ROS) Signup and view all the answers

What is the main function of acute phase proteins as part of innate immunity?

Regulate immune responses through cytokine production Signup and view all the answers

What is the main role of complement proteins in relation to innate immunity?

Enhance phagocytosis and inflammation against pathogens Signup and view all the answers

Which type of receptors are known as Pattern Recognition Receptors (PRRs)?

All of the above Signup and view all the answers

Which cytokines are responsible for the recruitment of neutrophils during an infection?

IL-8 and PGE2 Signup and view all the answers

What is the main function of Type III interferons (IFN-λ) in innate immunity?

Inhibiting viral replication Signup and view all the answers

Which type of cells express receptors for interleukin-2 (IL-2R)?

NK cells Signup and view all the answers

What is the result of the activation of Toll-like receptors (TLRs) on macrophages and dendritic cells?

Expression of integrins Signup and view all the answers

Which substance is NOT necessary for effective functioning of innate immunity?

Kynurenine Signup and view all the answers

What is the main function of Fc RIII (CD16) in NK cells?

Killing mechanism induction Signup and view all the answers

Which molecules bind microbial carbohydrates to initiate the lectin pathway of complement activation?

Mannan-binding lectin and C-reactive protein Signup and view all the answers

What are the cardinal signs of inflammation?

Redness, swelling, heat, and pain Signup and view all the answers

What is the main role of nucleotide oligomerization domain-like receptors (NLRs) in innate immunity?

Recognition of PAMPs on pathogens Signup and view all the answers

What is the function of scavenger receptors in innate immunity?

Initiation of phagocytosis Signup and view all the answers

What is the key function of cytoplasmic signaling receptors known as Toll-like receptors (TLRs)?

Cytokine gene expression induction Signup and view all the answers

What is the main function of the tight junctions in the body's epithelia?

To provide a barrier to penetration by pathogens Signup and view all the answers

Which of the following is NOT a significant function of the gastrointestinal tract's resident bacteria?

Induction of clonal expansion of B and T lymphocytes Signup and view all the answers

What is the main defense factor in the lower respiratory tract?

Lubrication of alveoli by surfactants Signup and view all the answers

What is the primary function of natural killer (NK) cells as part of the innate immune system?

Killing infected cells nonspecifically Signup and view all the answers

Which type of cells are widely distributed throughout the body and acquire special designations depending on their location?

Macrophages Signup and view all the answers

What is the role of Langerhans cells and dendritic cells in the skin?

Recognition and processing of antigens Signup and view all the answers

What is the main function of mucus-secreting goblet cells in the upper respiratory tract?

Trapping particles and sweeping them upwards Signup and view all the answers

Which type of cells provide a barrier to infection and modulate the recruitment and activation of phagocytes?

Epithelial cells Signup and view all the answers

What is the role of surfactants secreted by Type II pneumocytes in the lower respiratory tract?

Lubrication of alveoli and prevention of collapse Signup and view all the answers

What is the main function of Paneth cells in the gut?

Keeping intestinal organisms in check by secreting antimicrobial peptides Signup and view all the answers