lecture 19 quiz- immunology

What is the primary function of antibodies in the clearance of pathogens?

Antibodies enhance the complement system and facilitate phagocytosis.

Where are antibodies typically produced in relation to the site of infection?

Antibodies are produced at a distance from the site of infection and travel through the bloodstream.

Which of the following is the primary target of antibodies?

Extracellular bacteria and fungi

What is the role of antibodies in vaccine-induced immunity?

Antibodies provide protection against subsequent infection by stimulating the production of antibodies specific to particular antigens. Signup and view all the answers

How can antibodies contribute to tissue damage?

Antibodies can trigger immune responses that inadvertently damage normal tissues, leading to autoimmune diseases or contributing to transplant rejection. Signup and view all the answers

What is the importance of maintaining a balanced immune response involving antibodies?

Excessive antibody production or activity can lead to immune-mediated tissue damage and contribute to the development of immune-related disorders. Signup and view all the answers

What is the role of FcγRs expressed by macrophages and neutrophils?

Promoting opsonization of antibody-coated pathogens Signup and view all the answers

What is the function of immunoreceptor tyrosine-based inhibitory motifs (ITIMs) found in some Fc receptors?

Dampening immune responses by inhibiting cell activation Signup and view all the answers

How does phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) in Fc receptors affect cellular responses?

Leads to activation of downstream signaling cascades Signup and view all the answers

Which cellular responses are typically triggered by the activation of Fc receptors?

Phagocytosis, antibody-dependent cellular cytotoxicity (ADCC), or cytokine release Signup and view all the answers

What is the main role of Fc receptors in mediating immune responses?

Balancing immune responses to prevent excessive inflammation or tissue damage Signup and view all the answers

How do Fc receptors contribute to antibody-coated pathogen clearance?

By phagocytosing antibody-coated pathogens through opsonization Signup and view all the answers

What is the primary function of Fc receptors on immune cells?

To bind to the Fc region of antibodies and facilitate immune responses Signup and view all the answers

Which of the following is NOT a characteristic of the diversity of Fc receptors?

Fc receptors can directly induce phagocytosis of antibody-bound targets Signup and view all the answers

How do different antibody isotypes interact with Fc receptors?

Fc gamma receptors primarily recognize IgG antibodies Signup and view all the answers

What is the relationship between leukocyte populations and Fc receptor expression?

Leukocytes express specific Fc receptors that mediate cell type-specific responses Signup and view all the answers

Which of the following is a key consequence of the diversity of Fc receptors?

It allows for nuanced and tailored immune responses to different antibody-antigen complexes Signup and view all the answers

How do Fc receptors contribute to the opsonization of pathogens?

Fc receptors facilitate the recognition and binding of antibody-coated pathogens by phagocytes Signup and view all the answers

What is the primary function of the complement system in the immune response?

To opsonize pathogens and facilitate their recognition and elimination by phagocytic cells Signup and view all the answers

Which complement protein is primarily responsible for the opsonization of pathogens?

C3b Signup and view all the answers

What is the primary consequence of the formation of the membrane attack complex (MAC) during complement activation?

Lysis of the target pathogen's cell membrane Signup and view all the answers

How does the complement system contribute to the amplification of the immune response against pathogens?

By recruiting and activating additional immune cells, stimulating the release of inflammatory mediators, and increasing vascular permeability Signup and view all the answers

What is the primary role of the complement system in the elimination of pathogens?

To facilitate the recognition and ingestion of pathogens by phagocytic cells Signup and view all the answers

How is the activation of the complement system regulated to prevent excessive tissue damage?

By the presence of regulatory proteins that prevent excessive activation Signup and view all the answers

Which of the following statements about the alternative pathway of complement activation is correct?

It can be spontaneously initiated by the hydrolysis of C3. Signup and view all the answers

Which of the following is a consequence of complement activation?

All of the above. Signup and view all the answers

Which pathway of complement activation is initiated by the binding of mannose-binding lectin or ficolins to microbial carbohydrates?

Lectin pathway Signup and view all the answers

What is the central component of the complement cascade that is cleaved and activated, regardless of the pathway?

C3 Signup and view all the answers

Which of the following statements about the classical pathway of complement activation is correct?

It is initiated by the binding of C1 complex to antigen-antibody complexes, primarily IgM or IgG antibodies. Signup and view all the answers

Which of the following statements about the regulation of complement activation is correct?

Regulatory proteins ensure that complement is only activated under appropriate conditions and is properly controlled to maintain immune homeostasis. Signup and view all the answers