Adaptive Immunity Flashcards
What are the two main branches of the immune system?
Innate immunity and adaptive immunity.
What characterizes adaptive immunity?
Specificity and memory.
What triggers an adaptive immune response?
Antigens.
What are antigens?
Molecules that stimulate a response by T and B cells; molecules the body recognizes as foreign and worthy of attack
What are epitopes?
3D regions on antigens that antibodies or TCRs bind to.
What is an immunogen?
A molecule that provokes an immune response.
What are the two main types of adaptive immunity?
Humoral and cell-mediated immunity.
What is humoral immunity mediated by?
B cells and antibodies.
What is cell-mediated immunity mediated by?
T cells.
What do B cells differentiate into?
Plasma cells and memory B cells.
What is the role of plasma cells?
To produce antibodies.
What do memory B cells do?
Provide long-term immunity.
What are the main types of T cells?
Helper T cells, cytotoxic T cells, and regulatory T cells.
What do helper T cells do?
Helps regulate B cells and macrophages by providing necessary signals and growth factors; Activate B cells and cytotoxic T cells.
What do cytotoxic T cells do?
Kill infected cells.
What is the role of regulatory T cells?
Suppress immune response to prevent autoimmunity.
What is clonal selection?
Activation and expansion of lymphocytes with specific receptors.
What is clonal expansion?
Proliferation of activated lymphocytes.
What is immunological memory?
Ability of the immune system to respond more rapidly on second exposure.
What are the five classes of antibodies?
IgG, IgA, IgM, IgE, IgD.
What is the most abundant antibody in circulation?
IgG.
Which antibody is the first produced during an infection?
IgM.
Which antibody is important in mucosal immunity?
IgA.
Which antibody is involved in allergic reactions?
IgE.
What is the function of IgD?
Functions mainly as a receptor on B cells.
What are major histocompatibility complex (MHC) molecules?
Glycoproteins found in the membranes of nucleated cells of vertebrate animals that present antigens to T cells; hold & position antigenic epitopes for presentation to immune cells; can only show antigens that are made of proteins
What cells express MHC class I?
All nucleated cells.
What cells express MHC class II?
Antigen-presenting cells (APCs) like macrophages, dendritic cells, and B cells.
What is antigen processing and presentation?
Mechanism by which cells display antigen on MHC molecules.
What does the T cell receptor (TCR) do?
Recognizes antigens bound to MHC molecules.
What is the primary immune response?
The initial response to an antigen.
What is the secondary immune response?
A faster and stronger response upon re-exposure.
What is an antigen-presenting cell (APC)?
A cell that displays antigen with MHC to T cells.
What is neutralization in terms of antibodies?
Block the activity of an antigen; blocking pathogen binding to host cells.
What is opsonization?
Coating of pathogen by antibodies to enhance phagocytosis.
What is agglutination?
Clumping of pathogens by antibodies: Each antibody has 2 can bind to 2 epitopes at once… numerous antibodies can aggregate antigens together…agglutination of soluble molecules causes them to become insoluble & precipitate…increases the chances of phagocytosis and/or being filtered out of the blood by spleen
What are naïve lymphocytes?
Lymphocytes that have not yet encountered an antigen.
What does the CD4 marker identify?
Helper T cells.
What does the CD8 marker identify?
Cytotoxic T cells.
The types of T helper cells and their functions.
Type 1: assist macrophage and regulate immunity
Type 2: assist B cells and humoral immunity
