micro chapter 17 part 3
cellular immunity: the __ of the T cell recognizes MHC and allows __ to recognize epitope-both have to bind at the same time for it to be successful
CD, TCR
T-cell characteristics: if the cell expresses __ with TCR, it will commit to be a helper T cell
CD4
T-cell characteristics: TH (__) bind antigen presented on MHC class 2 of the __-__ cell (APCs=dendritic cells, macrophages, B cells)
CD4, antigen-presenting
helper T cells: effector functions of __ cells: recognize antigens presented on MHC class 2 of APCs (once activated-release __)
CD4, cytokines
cytotoxic T cells: effector functions of __ cells: Tc induces apoptosis by releasing digestive enzymes (perforins and granzymes), and also released cytokines that alert neighboring cells
CD8
cytotoxic T cells: effector functions of __ cells: recognize antigen on MHC class 1 of infected host cells
CD8
T-cell characteristics: two main CD subsets in T cells: __ (Tc) and __ (TH); two main MHC classes: __ __ and __ __
CD8, CD4, class 1, class 2
T-cell characteristics: is a cell expresses __ with TCR, it will commit to be a cytotoxic T cell; any __ can present intracellular pathogens on its surface-MHC class 1
CD8, CD8
T-cell characteristics: Tc (__) bind antigen presented on MHC class 1 of any __ host cell
CD8, nucleated
cellular immunity: __ is a receptor for HIV-infects helper T cells
HIV
which maternal antibody classes protect a breastfed newborn?
IgA
Why is negative selection important?
It eliminates lymphocytes that would otherwise recognize "self" molecules
mechanism: step 1: clonal selection: __ __ cells will find a pathogen, detect it, take it in, process it, present on MHCs
sentinel dendritic
cytotoxic T cells: cytotoxic T cell with CD8 binds to __ __ __, TCR recognizes epitope that is bound to it and cytotoxic T cells releases toxins, specifically __ and __ to induce apoptosis
MHC class 1, perforin, granzymes
mechanism: step 1: clonal selection: pool of T cells available, __ __ is able to recognize antigens presented on MHCs-this one will be selected
specific clone
__ __ can only be activated by intracellular antigens when presented on MHC
T cells
cellular immunity: helper T cells (TH) and cytotoxic T cells (Tc) have __ and __ of __ to recognize antigens only presented on MHC of others cells (MHC + antigen)
TCR, clusters, differentiation
T-cell characteristics: __ cells recognize antigens presented on MHC class 2 molecules
TH
T-cell characteristics: __ cells recognize antigens presented on MHC class 1 molecules
Tc
what is meant by clonal selection?
The antigen, by binding to the lymphocyte receptor, "selects" which lymphocyte may begin multiplying.
what is the function of lymph nodes?
there are secondary lymphoid organs; where B cells and T cells gather and encounter antigens that flowed through the lymphatic vessels from the tissues
how does a naive lymphocyte differ from an activated one?
a naive lymphocyte has never "seen" the epitope to which it is programmed for; activated lymphocytes have encountered the epitope and have received any required signals to proliferate and elicit the corresponding adaptive immune response
would a plasma cell produce antibody molecules of the same specificity or different specificities?
a single specificity; each B cell is programmed to recognize a specific epitope, and all plasma cells that descend from that B cell make antibodies that bind to the particular epitope
__ immune system: acquired through infection or vaccination, specific recognition and memory
adaptive
how does the ability to bind antigen increase as B cells multiply?
affinity maturation; mutations occur in the multiplying B cells, and the progeny that has the strongest affinity for the antigen is more apt to multiply
during maturation, undergo __ __: __ and __ selection before released from thymus; migrate to lymphatic system and concentrate in the __ __
thymic selection, positive, negative, lymph nodes
immature lymphocytes that are destined to be T cells
thymocytes
what kind of diseases would be expected to occur as a result of lack of negative selection of T or B lymphocytes?
autoimmune diseases
thymocytes leave bone marrow and migrate to the __- __ TCR here and associate TCR with the __-__ (CD); all TCRs expressed on one T cell recognize the same antigen-__ __
thymus, mature, co-receptor, same specificity
__-__ immune response: activated by intracellular antigen and presented on MHC
cell-mediated
__-__ immune response: defend against intracellular pathogens and cancer by binding to and initiating apoptosis in infected cells or cancer cells
cell-mediated
mechanism: step 2: clonal expansion: activated cells leave lymph nodes and circulate in the body-__ and other __ will attract cytotoxic T cells to the site of infection and they look for infected cells that has an antigen presented on their MHC __ __-destroy it
chemokines, chemoattractants, class 1
T-cell characteristics: __ __ is the MHC class expressed by all nucleated cells in the body (exceptions are erythrocytes and thrombocytes, non-nucleated)-have the ability to bind __ pathogens onto their MHC and express it on their surface
class 1, intracellular
T-cell characteristics: MHC __ __ can only be expressed by APCS (dendritic cells (phagocytes), macrophages (phagocytes), and B cells); whenever using this class, presents to get confirmation from __ __ __, must bind to antigen to be able to present on surface
class 2, helper T cells
mechanism: step 2: __ __: activated T cells proliferate and differentiate into effector T cells and memory T cells
clonal expansion
cytotoxic T cells: released, undergo __ __, leave lymph, to to infected site-look for infected cells; know they are infected because something able to bind __ __ __ has bound and presented it (one method of communication)
clonal expansion, MHC class 1
helper T cells: effector function of CD4 cells: secrete cytokines that: 1. activate B cells and induce B cell __ __; gives __ to B cell to activate humoral response
clonal expansion, confirmation
undergo __ __ to give effector T cells (active helper T cell or active cytotoxic T cell) that will mount immune response against pathogen; __ __ __ will be long-lived and get activated upon subsequent exposures
clonal expansion, memory T cell
mechanism: step 1: __ __: dendritic cells migrate through the lymph and present epitope on MHC to mature naive T cells; activation of T cell
clonal selection
T cells wait in lymph nodes to be activated-will be activated if matching by release of __ from dendritic cell (__ __)
cytokines, clonal selection
mechanism: step 2: clonal expansion: __ __ __ are toxic to infected cells
cytotoxic T cells
which cell type recognizes peptides presented on MHC class 1 molecules?
cytotoxic T cells recognize antigen presented on an MHC class 1 molecule; whereas helper T cells can recognize antigen presented on an MHC class 2 molecules
mechanism: step 1: clonal selection: cytokines released can activate __ __ __ and __ __ __
cytotoxic T cells, helper T cells
__ __ brings antigen to T cell in lymph nodes; these are in __ (skin, mucosal layer) scouting to present antigen on MHC-bring to closest lymph node
dendritic cell, tissue
which type of leukocyte functions as a main bridge between the innate and adaptive immune system?
dendritic cells
helper T cells and cytotoxic T cells both produce __ T cells and __ T cells (effector cytotoxic T cells and effector memory T cells; cytotoxic helper T cells and memory helper T cells)
effector, memory
mechanism: step 2: clonal expansion: activated TH (CD4) cells, by MHC class 2-bound antigen, differentiate into __ helper T cells and __ TH cells
effector, memory
mechanism: step 2: clonal expansion: activated Tc (CD8) cells, by MHC class 1-bound antigen, differentiate into __ cytotoxic T cells and __ Tc cells
effector, memory
How would the adaptive immune response be affected if memory cells could not be produced?
every response would be equivalent to a primary response (taking a week or so to develop, and first antibodies made would be IgM)
mechanism: step 2: clonal expansion: __ __ __: core of immune response through cytokines that are released (mainly __)-activate other cytotoxic T cells, B cells, phagocytes, amplifying immune response
helper T cells, interleukins
__ immune response: activated by extracellular antigen
humoral
__ immune response: defend against extracellular pathogens by binding to antigens, thereby neutralizing pathogens or making them better targets for phagocytes and complement proteins
humoral
__ __: internal defense mechanism against pathogens
immune system
__ immune system: immediate, non-specific immunity, no learning process or memory
innate
cellular immunity: pathogen went __ cell and is being presented on the __: could be a pathogen taken in and __; __ __-infect cell and replicates in cell, proteins that are made can be presented on MHC-constant monitoring
inside, surface, phagocytized, viral components
cellular immunity: carried out by T cells which combat __ pathogens (viral protein within a cell, phagocytized molecules)
intracellular
helper T cells: effector function of CD4 cells: secrete cytokines that: 2. activate __ (and other phagocytes) to increase power and use to form giant cells: increased __, __, number of __; (more effective!)
macrophages, size, metabolism, lysosomes
__ in the thymus decides whether it will be a helper T cell or cytotoxic T cell; thymocytes are not specialized when they travel to the thymus, specialize in thymus during __
maturation, maturation
cytotoxic T cells: __ __ cells ensure faster secondary response
memory Tc
Could a TC cell induce apoptosis in a "self" cell that lost the ability to produce MHC class I molecules?
no, Tc cells rely on antigen presentation on MHC class 1 molecules to recognize that a cell is infected; natural killer cells could
mechanism: step 1: clonal selection: dendritic cells can present on class 2, but are __ and can present on class 1; can activate both __ T cells and __ T cells-considered a bridge between innate and adaptive immune system
nucleated, helper, cytotoxic
helper T cells: effector function of CD4 cells: secrete cytokines that: increase macrophage __: increases size, metabolism, number of lysosomes, produces __ __ and other toxic compounds
power, nitric oxide
helper T cells: effector function of CD4 cells: secrete cytokines that: 3. direct and support Tc cells __ and __ (help T cells make more faster)
proliferation, differentiation