Chapter 7B Flashcards
Two properties distinguish adaptive immunity from innate immunity:
1. X
2. Memory
Specificity
Adaptive specific immunity involves the actions of two distinct cell
types: X and X cells
B lymphocytes (B cells) and T lymphocytes (T cells).
B cells originate and develop in the X and finish their maturation
process in peripheral lymphoid tissues such as the spleen.
bone marrow ( B cells Bonemarrow)
B cells are responsible for the production of X or immunoglobulins
antibodies
Mechanisms of adaptive specific immunity that involve B cells and antibody
production are referred to as X immunity.
humoral
- T cells originate in the bone marrow and migrate into the X for maturation,
selection (Tc and Th) and subsequent export to the peripheral lymphoid tissues
thymus
T cells function as the central orchestrator of both innate and adaptive immune
responses.
- They are also responsible
for destruction of cells
that are…
infected with
intracellular pathogens.
The targeting and
destruction of
intracellular pathogens
by T cells is called cellmediated immunity,
or X
cellular immunity.
The antibodies involved in humoral immunity often bind pathogens and
toxins before they can attach to and invade host cells:
- It works mainly against intra/extracellular pathogens in intra/extracellular spaces: any viruses,
bacteria, or fungi that are in body fluids inside/outside cells.
outside
- Pathogens that have already gained entry to host cells are largely
protected from the humoral antibody-mediated defenses
Antibody-mediated immunity: involves antibodies that bind to antigens
in X (such as blood and lymph).
body humors or fluids
B cells transform into X cells, which synthesize and secrete antibodies.
* A given antibody can bind to and inactivate a specific antigen
plasma
Cellular immunity targets and eliminates intra/extracellular pathogens through the actions of T cells. It is particularly effective
against:
- intra/extracellular pathogens, which include any viruses, bacteria, or
fungi that are inside cells; - some cancer cells and
- foreign tissue transplants.
intra
Cell-mediated immunity: cytotoxic T cells directly/indirectly attack invading
antigens. Thus, cell-mediated immunity always involves cells attacking
cells.
- T cells also play a more central role in orchestrating the overall
adaptive immune response (humoral as well as cellular) along with the
cellular defenses of innate immunity.
directly
Despite the differences:
* Both types of adaptive immunity are triggered by X
- Helper T cells aid the immune responses of both cell mediated and
antibody-mediated immunity.
antigens.
see p 14 for t and b cell overview
ok
The antibody produced in
response to an antigen binds only
to a very small site on the antigen
known as x
epitope: “smallest unit of an antigen (ex. microbe) to which an
antibody or cell can bind”.
true/false:
A single antigen may possess several different epitopes, and different
antibodies may bind to different epitopes on the same antigen
true
Proteins
Lipids and nucleic acids
Carbohydrates
put in order of most to least effective as antigens
proteins, ch, lipids
Immunoglobulins or antibodies, are molecules produced by activated B cells and
plasma cells in response to exposure to antigens.
true.false
true
immunoglobulins can be found…
- Bound to the membrane of a inf. B, acting as a receptor
2) Soluble, secreted by X and plasma cells
upon antigen exposure, and allowing the immune system
to recognize and effectively respond to a myriad of
pathogens
activated B cells
Clonal restriction: a B lymphocyte can only produce
specific immunoglobulins for a single type of antigen.
true.false
true
The basic structure of an antibody monomer consists of four protein
chains held together by disulfide bonds:
- Two largest chains identical to each other: X chains.
- Two smaller chains identical to each other: X chains.
- Joined together, the heavy and light chains form a basic Y-shaped
structure.
heavy
light
An immunoglobulin
recognizes multiple antigens
true/false
false, only one antigen
The trunk of the Y is also called the Fc region, for “fragment of
crystallization,” and is the site of complement factor binding and binding
to phagocytic cells during antibody-mediated X
opsonization. (Opsonization is the process of recognizing and targeting invading particles for phagocytosis)
Opsonization is an immune process which uses opsonins to tag foreign
pathogens for elimination by phagocytes
2 types of opsonins: complement C3b and antibodiesX
antibodies
The constant region of an antibody molecule determines its class,
or isotype.
* The five classes of antibodies are IgG, IgM, X, IgD, and IgE
which is the most abundant and versatile?
X = IgA
answer to question = IgG
Different classes of antibody play important roles in the body’s
defense against pathogens.
* These functions include:
- neutralization of pathogens
- X for phagocytosis,
- agglutination,
- X activation,
- antibody-dependent cell-mediated cytotoxicity.
* For most of these functions, antibodies also provide an important
link between adaptive specific immunity and innate nonspecific
immunity.
opsonization
complement activation
The major histocompatibility complex (MHC) is a collection of genes coding for
MHC X found on the surface of all nucleated cells of the body.
- In humans, the MHC genes are also referred to as human leukocyte antigen (HLA)
genes. - X, are the only cells that do not express
MHC molecules on their surface. - There are two classes of MHC molecules involved in adaptive immunity, MHC I and
MHC II.
molecules
Mature red blood cells, which lack a nucleus
MHC I is found on all nucleated cells: present normal self-antigens as well as
abnormal or nonself pathogens from inside/outside the cell to the effector T cells involved in cellular immunity.
- MHC II is found on X, dendritic cells, and B cells (APCs); they present
abnormal or nonself pathogen antigens from inside/outside the cell for the initial activation of T cells.
inside
macrophages
outside
MHC 2: present in specialized cells = ….. cells. They have the ability to
present antigens specifically for
the purpose of activating T helper
cells.
antigen presenting cells
MHC antigen (!)
MHC 1: binds TCR + CD8, expressed on all nucleated cells, presents antigens from the inside to CD8+ cytotoxic T cells
MHC2: binds TCR + CD4, expressed on APC’s, presents antigens from the outside to CD4+ helper T cells
ok
Proffesional antigen-presenting cells (APCs) have the ability to present antigens
(through the antigen binding to MCHII) specifically for the purpose of activating X cells
T
helper
- Professional APCs are:
- macrophages
- …. cells
- B cells
dendritic
While all APCs play a similar role in adaptive immunity, there are some important
differences to consider:
Whilst macrophages and dendritic cells’ primary role is phagocytes (ingest and kill pathogens that penetrate first-line barriers), the B-cells primary role is….
Production and secretion of antibodies
Whilst macrophages and dendritic cells’ receptors are nonspecific, B-cells receptors are ….
antigen-specific (IgD and IgM)
