B & T Lymphocytes
Role of Natural Killer T-cell
1) Natural killer T-cell recognize foreign antigen presented by the major histocompatibility complex, CD1d. 2)When activated, these cells secrete cytokines, cytotoxic molecules and attack some virus-infected and cancer cells. These activities are similar to those of both T-helper and cytotoxic T-cell lymphocytes.
How do T-helper cells function?
1) T-helper cells bind to and act as co-signal for the activation of B-cell lymphocytes 2) T-helper cells activate cytotoxic T-cells and memory T-cells. 3) T-helper cells are activated presented with foreign antigens fragments by major histocompatibility complex (MHC class II) molecules, which are expressed on the surface of macrophage or dendritic antigen presenting cells
Primary actions of B-Cell
1)Function as antigen-presenting cells 2)Make antibodies against antigens 3)Form memory B cells after activation by antigen interaction
What do activated B-cell lymphocytes form?
Plasma B-cells or memory B-cells
Name the 4 primary T-cell lymphocytes
T-helper cells, cytotoxic T cells, memory T-cells and natural killer T-cells
B-Cell Lymphocytes
a type of white blood cell which originate and mature in the bone marrow, function as part of the adaptive or acquired immune system.
What are T-cell Lymphocytes?
a type of white blood cell which originate in the bone marrow, but mature in the thymus gland, function in the cell-mediated component of acquired immune response
Name two stages of B-cell activation
antigen presentation and activation
Memory T-cell lymphocytes
are formed from activated T-cells that are specific to the foreign antigen recognized during the initial immune response. These cells have a memory for the antigen survive for a long time, respond quickly following a second exposure to the same antigen.
Natural killer T-cells
exhibit actions similar to both the innate and acquired immune systems.
What are memory B-cell lymphocytes?
formed from activated B cells that are specific to the antigen encountered during the primary immune response. These cells survive for a long time, and can respond quickly following a second exposure to the same antigen.
After ingestion of a foreign antigenic pathogen what happens?
fragments of the pathogen's proteins are digested and attached to a class II major histocompatiblity complex protein. This complex is transported to and presented on the outside of the cell membrane to B-cells
Cytotoxic T-cell-lymphocytes
kill cells expressing a foreign antigen characteristic of cancer or cells infected by viruses. Antigens inside a cell are expressed to the surface of the cell by the major histocompatibility complex class I (MHC class I) molecule, where they can be recognized and destroyed by the T cell.
T-helper cells
promote the activity of other immune cells in the acquired immune response.
What does full activation require?
requires a secondary, co-signal provided by a T helper cell that has been presented with the same antigen from a macrophage or dendritic cell.
What is the function of Plasma B-cell Lymphocytes?
secrete large amounts of antibodies, which assist in the destruction of foreign pathogens.
