07. Immunity Flashcards
Describe natural active immunity
Individual contracts pathogen without medical intervention. This means that the humoral immune response is initiated, and the person eventually makes their own specific and free-floating antibodies and develops an immunological memory of this pathogen.
Describe natural passive immunity
Baby receives specific complementary and free-floating antibodies from their mother by breast feeding or the placenta. This means that the baby has no immunological memory.
Describe artificial passive immunity
Person receives specific complementary and free-floating antibodies by medical intervention (e.g. anti toxin). This means that the person has no immunological memory.
Describe artificial active immunity
Individual contracts pathogen with medical intervention. This means that the humoral immune response is initiated, and the person eventually makes their own specific and free-floating antibodies and develops an immunological memory of this pathogen.
Define a vaccine
A vaccine is a solution containing a dead, weakened or attenuated form of the of the pathogen or antigen, or mRNA instructions to make an antigen.
Define herd immunity
Herd immunityis when a large portion of a community (normally more than 90%) becomes immune to a disease, making the spread of disease from person to person unlikely as there are less potential hosts.
Define emerging disease
An infectious disease that is new to the human population.
Define re-emerging disease
A disease that reappears after being absent in a population for a significant period of time.
Endemic
The normal level of incidence of a disease in a population.
Epidemic
A significant rise in the level of incidence of a disease in a population
Define pandemic
A significant rise in the level of incidence of a disease globally
Define antigenic drift
Small and gradual mutations in the genes encoding for viral surface antigens
Define antigenic shift
Sudden and significant mutations in the genes encoding for viral surface antigens
Give 5 methods of disease transmission
Airborne, aerosol, direct physical contact, indirect physical contact and faecal-oral transmission
Outline the steps in making monoclonal antibodies
Identify antigen on desired cell (e.g. cancer cell or autoimmune disease causing B cell)
Vaccinate a mouse with the desired antigen- mouse will select specific and complimentary B cells to the antigen
B cells are extracted
Fuse mouse B cells with a myeloma cancerous cell to produce a hybridoma
Select appropriate hybridoma
Monoclonal antibodies are collected and purified
Define a monoclonal antibody
Monoclonal antibodies (mAb) are laboratory produced antibodies that can bind to specific and complementary antigens on a cell.
Define allergen
Allergens are antigens that the immune system recognises as non-self and initiates a strong immune response towards.
Describe an allergic reaction.
Allergies are inappropriate or exaggerated reactions of the immune system to unimportant stimuli, an allergen. This means that there is an excessive release of histamine by mast cells causing exaggerated inflammation and mucus production.
State the two steps to allergies occurring
Sensitisation
Degranulation
Describe the two steps to allergies occurring
Sensitisation. This means that after the humoral immune response in response to the allergen, specific complementary and free floating IgE antibodies are made and some of these IgE antibodies will bind to mast cells by their non-variable region in the connective tissue.
Degranulation. This means that on secondary exposure to the same allergen it attaches to the specific and complementary antigen binding sites on IgE on the mast cells forming a cross link which leads to excessive release of histamine, excessive mucus production and contraction of smooth muscle in the airways.
State what medicine could be given to treat a bacteria infection
Antibiotics (these often break down the peptidoglycan cell wall)
State what medicine could be given to treat a viral infection
Antivirals (these are enzyme inhibitors)
Outline the different types of monoclonal antibodies
Conjugated monoclonal antibodies have a toxic drug attached to them to deliver them directly to the cell.
Bispecific monoclonal antibodies have 2 different antigen binding sites
Humanized monoclonal antibodies which have part mouse and part human protein as they are often made in mice anyway .
Describe how a monoclonal antibody works
Monoclonal antibodies are designed to have antigen binding sites that are specific and complimentary to a particular ____antigen . They attach to the antigen.
This means that they will flag for phagocytosis by macrophages/
Activate complement proteins/
Activate natural killer cells/
Deliver toxic drug if conjugated – This reduces chemotherapy effects on healthy cells as it will bind directly to cancer cells
State the two types of diseases which monoclonal antibodies can be designed to target
Autoimmune and cancer
