Interaction between CD80/86 on antigen presenting cells and CD28 on T cells
Acquired immunodeficiency syndrome (AIDS) is a syndrome caused by the human immunodeficiency virus (HIV)
HIV
Retrovirus that attacks and destroys CD4+ T helper cells
There are two main types of HIV: HIV-1 and HIV-2, with HIV-1 being more common and widespread
Maternal-fetal immune tolerance
The placenta acts as a barrier and the mother's immune system becomes suppressed during pregnancy to prevent rejection of the fetus
Autoimmune diseases
Conditions where the immune system attacks the body's own tissues
Organ transplant rejection
1. Donor and recipient tissues are matched for compatibility
2. Immunosuppressant drugs are used to prevent rejection
Blood transfusion compatibility
Blood types must be matched to prevent antibody-mediated destruction of red blood cells
Complications of hemolysis (red blood cell destruction) include hyperkalemia, hyperphosphatemia, hemoglobinemia, and kidney damage
Humoral immunity
Immunity mediated by antibodies secreted into body fluids
Cellular immunity
Immunity mediated by T lymphocytes that directly attack and destroy target cells
Antigen
A piece of a foreign invader (e.g. bacteria) that the immune system recognizes
Antigen presenting cell
A cell that displays an antigen on its surface to be recognized by lymphocytes
MHC
A molecule on the surface of antigen presenting cells that displays the antigen
B lymphocyte
A lymphocyte that can differentiate into plasma cells to secrete antibodies
T lymphocyte
A lymphocyte that directly attacks and destroys target cells
T helper lymphocyte
A T lymphocyte that helps activate and coordinate the immune response
T cytotoxic lymphocyte
A T lymphocyte that directly kills target cells
T regulatory lymphocyte
A T lymphocyte that suppresses immune responses to prevent autoimmunity
Antibody
An immunoglobulin molecule secreted by plasma cells that binds to and neutralizes antigens
Types of antibodies
IgM
IgA
IgG
IgE
IgD
IgM
Large, cannot cross placenta, good at activating complement
IgG
Most abundant, small, crosses placenta, opsonizes bacteria, activates complement
IgA
Found in mucous membranes, first line of defense
IgE
Involved in allergic reactions and defense against parasites
IgD
Function unknown, produced first on naive B cells
Primary immune response
Involves IgM antibodies
Secondary immune response
Involves IgG antibodies
Lymphoid stem cells give rise to T and B lymphocytes
Naive B cells can differentiate into memory B cells or plasma cells
Plasma cells secrete antibodies
has invaded what's that fungus i'll destroy the fungus face to face baby self-mediated immunity what is this cancer i'll try to kill it face to face i am not secreting any antibodies into any fluids this is not who i am
B lymphocytes
They grow in the bone marrow and in birds they mature in the bursts of fabricious
T lymphocytes
They mature in the thymus gland
Types of T lymphocytes
T helper
T cytotoxic
T cytotoxic
Toxic through the cell, can destroy fungus cell, cancer cell, virus infected cell
T helper
Helps all kinds of cells, helps T cytotoxic, helps T suppressor/regulatory, helps B lymphocytes
T suppressor/regulatory cells
Prevents T cytotoxic from killing your own cells, tells T cytotoxic to attack foreigners not self
If there are problems with T regulatory/suppressor cells, T lymphocytes will attack your own cells leading to autoimmune diseases like lupus
Antigen
A foreign substance that stimulates the immune system to produce an immune response