Immune system -slide 42 to the end Flashcards
What are the 3 types of lymphocytes?
B lymphocytes
- Plasma cells => secrete antiboides
T lymphocytes
- Helper T cells => secrete cytokines
- Cytotoxic T cells => directly attack infected cells
NK cells
=> naturally killer cells
- Take care of cells that look weird…
Helper T cells recognize antigen bound to ______ (immune cells) CD4
Whereas cytotoxic T cells recognize antigen bound to ____ (non-immune cells) CD8
Helper T cells => MHC II
- immune cells
Cytotoxic T cells => MHC II
- Non- immune cells
T cells are part of ______ (specific / unspecific) immunity
Specific
- They make up 80? of circulating lymphocytes
What are the main types of T cells?
- Cytotoxic T cells
- Helper T cells
- Suppressor T cells
- Memory T cells ( provide immunological memory )
Describe B cells
- Part of specific immunity
- Make up 10-15% of circulating lymphocytes
- Differentiate (change) into plasma cells
- Plasma cells:
- Produce and secrete antibodies (immunoglobulin proteins) - Antibody-mediated immunity
- A chain of events that destroys the target compound or organism
Describe NK cells
- Part of the non-specific immunity
- Also called large granular lymphocytes
- Make up 5-10% of circulating lymphocytes
- Responsible for immunological surveillance
- Attack foreign cells, virus-infected cells, and cancer cells
Go see picture slide 46
Go
What is meant, when we say lymphocytes have clones?
- All lymphocytes contain proteins on their cell surface capable of binding a foreign antigen
- Lymphocytes that all bind a particular antigen (the same antigen) are called CLONES
What are the steps in an immune response?
- Naïve lymphocytes have not yet been stimulated
- Antigen stimulates a specific lymphocyte clone of cells that have surface receptors for the antigen
- Clonal expansion occurs as the cells multiple rapidly in response to antigenic stimulation
- Some new cells become one of three types of effector cells (plasma cells, helper T cells, cytotoxic T cells )
Go see slide 49
.
What is humoral immunity, and what cell is implicated in it?
B lymphocytes (B cells) are responsible for humoral immunity
- Clonal expansion of B cells results in the production of plasma cells
- Each clone of plasma cells produces a specific antigen binding protein called ANTIBODY
- Memory cells are also produced => allowing for a rapid and stronger secondary antibody response if antigen is encountered again
What is the difference in antibody concentration after a primary and secondary immune response?
In a first/primary exposure to an antigen, antibody concentration is smaller for a shorter period.
After a second exposure, response by B cells => a lot of antibody for a longer period of time (go see graphs slide 52)
What is the other name for antibodies?
Gamma globulin
What are the 5 classes of anitbodies, how do they vary?
They vary in their Fc region
- IgG - Most common, SECONDARY RESPONSE is IgG
- IgA - Secretory form (saliva, tears, breast milk etc)
- IgE - Involved in allergic responses
- IgM- Antibodies involved in primary response
- IgD- Found on surface of B cells, role unclear
What specific cell is involved in cell-mediated immunity? What is its role?
T cells (T lymphocytes)
- T cells are specialized to defend against intracellular pathogens
- Use contact-dependant signaling
- T cell receptors recognize foreign antigens only with major histocompatibility complex (MHC) proteins
- MHC proteins are found on all body cells, and they vary from one person to another
What are Major histcocompatibility complex?
MHC
- Antigen-presenting molecules
- They are reason for tissue rejection
- MHC proteins help our immune system defend against intracellular pathogens and cancers