front 1 What are the six categories of antibody effector functions? | back 1 Neutralization, opsonization, complement activation, ADCC, mast cell degranulation, agglutination. |
front 2 What is neutralization? | back 2 Antibodies block pathogens or toxins from entering cells. |
front 3 What is opsonization? | back 3 Antibodies coat pathogens to enhance phagocytosis. |
front 4 What is complement activation? | back 4 IgM or IgG trigger complement leading to pathogen lysis. |
front 5 What is ADCC? | back 5 NK cells kill antibody-coated target cells. |
front 6 What is mast cell degranulation? | back 6 IgE triggers release of histamine for allergy and parasite defense. |
front 7 What is agglutination? | back 7 Antibodies clump pathogens together for easier clearance. |
front 8 What are the characteristics of IgM? | back 8 First responder, pentamer, strong complement activation, good at agglutination. |
front 9 What are the characteristics of IgE? | back 9 Involved in allergies and parasites, binds mast cells, low concentration in serum. |
front 10 What are the characteristics of IgD? | back 10 Found on naïve B cells, functions mainly as a B cell receptor. |
front 11 What are the characteristics of IgA? | back 11 Mucosal immunity, dimer, found in secretions like saliva and lungs. |
front 12 What are the characteristics of IgG? | back 12 Main serum antibody, long half-life, crosses placenta, involved in opsonization and ADCC. |
front 13 What are Fc receptors? | back 13 Receptors that bind the Fc region of antibodies and trigger immune responses. |
front 14 What do Fc receptors do? | back 14 Translate antibody binding into cellular responses like phagocytosis or killing. |
front 15 What are ITAMs? | back 15 Activating signaling motifs that trigger immune cell activation. |
front 16 What are ITIMs? | back 16 Inhibitory signaling motifs that suppress immune activation. |
front 17 Which overrides: ITAM or ITIM? | back 17 ITIM overrides ITAM (inhibitory signals dominate). |
front 18 What is affinity? | back 18 Strength of binding between receptor and antigen-MHC. |
front 19 What is FcγR? | back 19 Fc receptor that binds IgG and mediates phagocytosis and ADCC. |
front 20 What is FcεR? | back 20 Fc receptor that binds IgE and triggers mast cell degranulation. |
front 21 What is FcαR? | back 21 Fc receptor that binds IgA and supports mucosal defense and phagocytosis. |
front 22 What is FcμR? | back 22 Fc receptor that binds IgM and regulates IgM responses. |
front 23 What is FcRn? | back 23 Neonatal Fc receptor that binds IgG and protects it from degradation. |
front 24 What are the two functions of FcRn? | back 24 Protect IgG from degradation and transfer IgG to fetus. |
front 25 What is IgG recycling via FcRn? | back 25 IgG is taken into cells, bound by FcRn in endosomes, protected from degradation, and released back into circulation. |
front 26 What is the significance of FcRn recycling? | back 26 Extends IgG half-life (~21 days) and supports long-term immunity. |
front 27 What is pIgR? | back 27 Poly-Ig receptor that transports antibodies across epithelial cells. |
front 28 Which antibodies use pIgR? | back 28 IgA and IgM. |
front 29 What is the role of the J chain? | back 29 Links antibody units together and is required for transport via pIgR. |
front 30 What is the function of pIgR? | back 30 Moves IgA and IgM to mucosal surfaces. |
front 31 How is pIgR different from FcRn? | back 31 pIgR exports antibodies to mucosa, FcRn protects antibodies in circulation. |
front 32 How is antibody secretion turned off? | back 32 Through negative feedback mechanisms. |
front 33 What is FcγRIIB? | back 33 An inhibitory Fc receptor on B cells that binds IgG-antigen complexes. |
front 34 What is the role of FcγRIIB? | back 34 Provides negative feedback to reduce antibody production. |
front 35 How do ITIMs function in FcγRIIB? | back 35 They send inhibitory signals to suppress B cell activation. |
front 36 What is feedback inhibition in B cells? | back 36 Increased IgG leads to increased inhibition of further antibody production. |
front 37 What are therapeutic antibodies? | back 37 Lab-made antibodies used for treatment of diseases. |
front 38 What is a mouse antibody? | back 38 Fully mouse-derived, highly immunogenic. |
front 39 What is a chimeric antibody? | back 39 Mouse variable region with human constant region. |
front 40 What is a humanized antibody? | back 40 Mostly human with only mouse CDR regions. |
front 41 What is a fully human antibody? | back 41 Entirely human, least immunogenic. |
front 42 What is Rituximab? | back 42 A chimeric antibody targeting CD20 to kill B cells, used for lymphoma and autoimmune diseases. |
front 43 What is Adalimumab? | back 43 A fully human antibody targeting TNF-alpha to reduce inflammation in autoimmune diseases. |
front 44 What is Ipilimumab? | back 44 A fully human antibody targeting CTLA-4 to enhance T cell activation in cancer therapy. |
front 45 What are the general steps of CD8⁺ T cell activation? | back 45 Recognition of antigen on MHC I, co-stimulation, cytokine signaling, clonal expansion, differentiation. |
front 46 What are the three signals for CD8⁺ T cell activation? | back 46 TCR + MHC I, CD28-B7 costimulation, cytokines (IL-2). |
front 47 What is the sequential model of CD8 activation? | back 47 CD4 T cells activate first, then help activate CD8 T cells. |
front 48 What is the simultaneous model? | back 48 CD4 and CD8 T cells are activated at the same time by the same APC. |
front 49 Which model is better supported? | back 49 Simultaneous model. |
front 50 What is dendritic cell licensing? | back 50 CD4 T cells activate dendritic cells to better stimulate CD8 T cells. |
front 51 What is the role of CD40 | back 51 CD40L? / CD40L on CD4 T cells binds CD40 on dendritic cells to activate them. |
front 52 What is cross-presentation? | back 52 Dendritic cells present external antigens on MHC I to activate CD8 T cells. |
front 53 What is the role of IL-2? | back 53 Promotes T cell growth and proliferation. |
front 54 Which cells produce IL-2? | back 54 Mainly CD4 T cells. |
front 55 How do cytotoxic T lymphocytes (CTLs) kill target cells? | back 55 Using perforin/granzymes and Fas–FasL pathways. |
front 56 What is perforin? | back 56 Protein that forms pores in target cell membranes. |
front 57 What are granzymes? | back 57 Enzymes that enter cells and trigger apoptosis. |
front 58 What is the Fas–FasL pathway? | back 58 FasL on T cells binds Fas on target cells to induce apoptosis. |
front 59 Why are adhesion molecules important? | back 59 They stabilize interaction between CTL and target cell. |
front 60 What is IFN-γ? | back 60 Cytokine that activates macrophages and has antiviral effects. |
front 61 What is lymphotoxin (LT)? | back 61 Cytokine involved in inflammation and cell killing. |
front 62 What are NK cells? | back 62 Innate lymphocytes that kill infected or cancer cells. |
front 63 What are characteristics of NK cells? | back 63 No antigen-specific receptors, rapid response, detect abnormal cells. |
front 64 What lineage are NK cells from? | back 64 Lymphoid lineage. |
front 65 What cytokines activate NK cells? | back 65 IL-12, IL-15, IL-2. |
front 66 What cytokine do NK cells secrete? | back 66 IFN-γ. |
front 67 How do NK cells decide to kill? | back 67 Balance between activating and inhibitory signals. |
front 68 What is the missing self model? | back 68 NK cells kill cells lacking MHC I. |
front 69 What is the balanced signals model? | back 69 NK cell activation depends on net activating vs inhibitory signals. |
front 70 Which NK model is more accurate? | back 70 Balanced signals model. |
front 71 What are inhibitory NK ligands? | back 71 MHC class I molecules. |
front 72 What are activating NK ligands? | back 72 Stress-induced molecules on infected or tumor cells. |
front 73 What is ADCC in NK cells? | back 73 NK cells bind IgG-coated targets and kill them. |