9.3 Flashcards
(10 cards)
- What is the basic structure of a typical antibody molecule?
It is a Y-shaped protein composed of two identical heavy chains and two identical light chains, with variable regions in the Fab (antigen-binding) segments and a constant Fc region for effector interactions.
- Which parts of the antibody mediate antigen binding and effector functions?
The Fab region binds to specific antigens, while the Fc region interacts with immune effector cells and complement proteins.
- What are the main formats of therapeutic antibodies?
Formats include full-length monospecific antibodies, bispecific antibodies, antibody fragments (e.g., Fab, scFv, nanobodies), and conjugated forms such as antibody-drug conjugates (ADCs) and immunotoxins.
- How do bispecific antibodies differ from conventional monospecific antibodies?
Bispecific antibodies are engineered to bind two different epitopes or antigens simultaneously, whereas monospecific antibodies bind only a single target.
- What are common mechanisms of action for therapeutic antibodies?
They work by neutralizing target antigens, blocking receptor-ligand interactions, inducing cell death via antibody-dependent cellular cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC), and delivering conjugated toxins or radioisotopes.
- How does antibody-dependent cellular cytotoxicity (ADCC) function?
In ADCC, the antibody’s Fc region binds to Fc receptors on effector cells (like NK cells), triggering the lysis of the target cell bound by the antibody’s Fab region.
- What are some challenges associated with developing therapeutic antibodies?
Challenges include high production costs, complex manufacturing, potential immunogenicity, stability and storage issues, and limitations in administration routes (often injectable).
- How can immunogenicity of therapeutic antibodies be reduced?
By using humanized or fully human antibodies, engineering the Fc region, and modifying glycosylation to reduce immune recognition.
- What strategies are used to build better or different therapeutic antibodies?
Approaches include Fc engineering for enhanced effector function or half-life, developing bispecific/multi-specific formats, creating antibody-drug conjugates for targeted cytotoxicity, and using antibody fragments for improved tissue penetration.
- Why are antibody-drug conjugates (ADCs) significant in therapy?
ADCs couple the targeting specificity of antibodies with potent cytotoxic agents, ensuring selective drug delivery to diseased cells while minimizing damage to healthy tissues.
