ADAPTIVE IMMUNITY Flashcards
Allows the body to recognize, remember, and respond to a specific stimulus, an antigen. Can result to the elimination of microorganisms and recovery from disease
ADAPTIVE IMMUNITY
It is the key cell involved in the adaptive immunity immune response. 7-10 um in diameter and has a large rounded nucleus that may be somewhat indented.
LYMPHOCYTES
What are the primary lymphoid organs
Bone Marrow
Thymus
What are the secondary lymphoid organs
Spleen
Lymph Nodes
Appendix
Tonsils
It is considered to be the largest tissue of the body with a total weight of 1300 to 1500 in adult. It functions as the center for antigen-independent lymphopoiesis
BONE MARROW
It is a small, flat, bilobed organ found in the thorax or chest cavity, approximately 97% of the cortical cells die in the thymus before maturing into T cells.
THYMUS
Lymphopoiesis or reproduction of lymphocytes happen in secondary lymphoid organs and is antigen-independent
T or F
False
Strictly dependent on antigenic stimulation
Formation of lymphocytes in the bone marrow is _________ independent
Antigen-independent
It is the largest secondary lymphoid organ, it removes old and damaged cells and foreign antigens from the blood
SPLEEN
What are the 2 main Splenic Tissue
Red Pulp- destroys old red blood cells
White Pulp- contains lymphoid tissue
It is located along lymphatic ducts and serve as central collecting points for lymph fluid from adjacent tissues, its main function is filtration
LYMPH NODES
Acts as a reference in standardizing names of membrane proteins found on all human white blood cells
Clusters of differentiation
CD3 is specific for Cell Type ______________
Thymocytes, T cells
CD4 is specific for Cell Type ______________
T helper cells, monocytes, macrophages
CD8 is specific for Cell Type ______________
Thymocytes subsets, Cytotoxic T cells
CD16 is specific for Cell Type ______________
Macrophages, NK Cells, Neutrophils
CD19 and CD21 specific for Cell Type ______________
B cells, follicular dendritic cells
CD56 is specific for Cell Type ______________
NK cells, subsets of T cells
Cells that have not encountered their specific antigen
VIRGIN or NAIVE LYMPHOCYTES
Populations of long lived T or B cells that have been stimulated by antigen, has a quick response to an encountered antigen
MEMORY CELLS
Has the capacity to produce harmful antibodies after differentiation into plasma cells, capable of antigen presenting
B LYMPHOCYTES
What are the 2 B Lymphocyte Subsets
B1 Cells- distinguished by CD5 marker, responds in microbial antigens
B2 Cells- Account for most B lymphocytes in adults, responds effectively to T-dependent antigen
STAGES OF B-CELL DIFFERENTIATION
Pro-B Cells
Pre-B Cells
Immature B Cells
Mature B Cells
Activated B Cells
Plasma Cells
Memory Cells
A stage in B Cell differentiation which the B-cell progenitors require direct contact with bone marrow stromal cells
Pro-B Cells
Cytokine necessary at early developmental stage of Pro-B Cells
Interleukin-7
Surface antigens in Pro-B Cells
CD19, CD45R, CD43, CD24, c-Kit, Tdt, RAG-1 and RAG-2
This CD marker appears early and remains on the B ce;; until it differentiates into plasma cell
CD19
It is distinguished by the appearance of complete IgM molecules on the cell surface
Immature B Cells
Other surface protein present on the immature B cell
CD21
CD40
MHC Class II molecules
It is termed as programmed cell death
APOPTOSIS
2 types of Mature B Cells
Marginal B Cells- remain in the spleen to respond quickly in blood borne pathogens
Follicular B Cells- migrate to lymph nodes and other secondary organs
Immunoglobulins present in Mature B cells
IgM
IgD
Surface protein of Mature B-cells
CD19
CD21
CD81
CD225
Lifespan of Mature B Cells
Few days if not in contact with antigen
Exhibit identifying markers that include CD25, transformation into blasts will give rise to both Plasma cells or Memory cells
Activated B Cells
This represents the most fully differentiated lymphocyte, main function is antibody production
Plasma Cells
Plasma cells are normally found in
Germinal centers in the peripheral lymphoid organs
Bone Marrow
This cells are found in germinal centers and have a long life span
Memory Cells
It is responsible for cellular immune responses and are involved in the regulation of antibody reactions in conjunction with B Lymphocytes
T LYMPHOCYTES
Surface marker of thymocytes that are committed to becoming T cells
CD44
CD25
Stages of T Cell differentiation
Double Negative Stage
Double Positive Stage
Mature T Cells
In this stage, rearrangement of the genes that code for the antigen receptor aka T-cell receptor (TCR) begins.
Double Negative Stage
Early thymocytes lack these two markers
CD4 and CD8
Double Negative Stage possesses these 4 CD markers
CD2
CD5
CD7
CD45R
Cytokines that interact with stromal cells
Interleukin-7
2 specific chain of the T cell receptor under Double Negative Stage
Alpha
Beta
Thymocytes expresses CD4 and CD8 in this stage
Double Positive Stage
It is a process in Double Positive Stage that allows only double positive cells with functional TCR receptors to survive
Positive Selection
It is a process in Double Positive Stage that takes place among the surviving double-positive T cells.
Negative Selection
Survivors of selection exhibit one of these two markers
CD4 75%
CD8 25%
T Lymphocyte Subsets
CD4+ subset: helper-inducer T cell
CD8+ subset: suppressor-cytotoxic T cell
What are the cells in T-cell subpopulation
Th1
Th2
T Regulatory cells
Th9 cells
Th17 cells
T-cell subpopulation cell that produce interferon gamma (IFN-y), Interleukin-2 (IL-2) and necrosis factor-B (TNF-B)
It also protect cells against intracellular pathogens by activating cytotoxic lymphocytes and macrophages
Th1 cells
T-cell subpopulation cell that helps B cells produce antibodies against extracellular pathogens and to generally regulate B-cell actitvity
Includes IL4, IL5, IL6, IL9, IL10, IL13
Th2 Cells
T cell subpopulation cells that possesses CD4 and CD25 antigen, it plays an important role in suppressing the immune response to self-antigens
T regulatory cells
T-cell subpopulation that produces IL-9 and appear to have proinflammatory effects, wards off fungi and extracellular bacteria
Th9 cells
T-cell subpopulation that produces IL-17 and IL-22, can increase inflammation and joint destruction, associated with autoimmune diseases such as Rheumatoid arthritis, Multiple sclerosis, Inflammatory bowel disease
TH17 cells
This cell have the ability to mediate cytolytic reactions and kill target cells without prior exposure to them, possesses CD16, CD56 and CD94, first line of defense against virally infected cells, intracellular pathogen infection, and tumor cells.
NATURAL KILLER CELLS
In response to IL2 NK cells become ______ cells
LAK Cells
This receptors delivers inhibitory signals
Inhibitory receptors
This receptors delivers signals to activate cytotoxic mechanisms
Activatory receptors
This type of cell recognize and lyse antibody coated cells through a process called __________________
Antibody-Dependent Cell cytotoxicity
Binding of Antibody-dependent Cell Cytotoxicity occurs in _________ for IgG
CD16 Receptor
Laboratory Identification of Lymphocytes
Density Gradient Centrifugation with Ficoll-Hypaque
Flow Cytometry
Fluorescence Microscopy (Direct and Indirect)
Rossette Technique
T Cells Characteristics
Develops in Thymus
Found in Blood 60-80%
Rosette formation with SRBCs
End products are Cytokines
CD2, CD3, CD4, CD8 antigen
Paracortical region of lymph nodes
B Cells Characteristics
Develops in bone marrow
Found in bone marrow, spleen, lymph nodes
Surface immunoglobulins
End products are antibodies
CD19, CD20, CD21, CD40, Class II MHC
Cortical region of lymph nodes
