Term
| What are the processes that mediate innate/natural immunity? |
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Definition
Phagocytosis
Activation of complement system
Release of interferons
Production of antibacterial peptides |
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Term
| Name the cells that mediate natural immunity. |
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Definition
Neutrophils
Macrophages
Natural Killer (NK) cells |
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Term
| What are the 3 different pathways that activate the complement system? |
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Definition
Classic pathway
Mannose-binding lectin pathway
Alternate or properdin pathway |
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Term
| What are the different outcomes of complement activation? |
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Definition
Killing of invading organisms by opsonization
Bridges innate and acquired immunity by activation of B cells
Disposal of waste products after apoptosis |
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Term
| Which type of immunity is more specific? |
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Definition
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Term
| What are the stimuli for development of acquired immunity? |
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Definition
| Antigens that are usually proteins |
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Term
| What are the types of acquired immunity? |
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Definition
| Cellular immunity Humoral immunity |
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Term
| Which WBC mediates cellular immunity? |
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Definition
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Term
| Which WBC mediates humoral immunity? |
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Definition
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Term
| What is humoral immunity primarily effective against? |
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Definition
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Term
| What is cellular immunity a major defense against? |
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Definition
| Viral, fungal and a few bacterial infections (e.g., tubercle bacillus) Tumor cells |
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Term
| Where are the precursors of all lymphocytes formed? |
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Definition
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Term
| Where do T lymphocytes develop? |
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Definition
|
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Term
| Where do B lymphocytes develop? |
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Definition
Bone marrow
In the fetal liver, before birth |
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Term
| What is the fate of the lymphocytes after developing into T or B subtypes? |
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Definition
| They migrate to the lymph nodes and bone marrow everywhere. |
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Term
| How are B lymphocytes further classified? |
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Definition
Plasma cells
Memory B cells |
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Term
| How are T lymphocytes classified? |
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Definition
Helper T cell
Cytotoxic T cell |
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Term
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Definition
| They are glycoprotein markers present on the surface of T lymphocytes that differentiate helper T CD4) from cytotoxic T cells (CD8). |
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Term
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Definition
| Clusters of differentiation |
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Term
| What are the subtypes of helper T cells? |
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Definition
T helper 1 (involved in cellular immunity)
T helper 2 (involved in humoral immunity) |
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Term
| What are the subtypes of cytotoxic T cells? |
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Definition
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Term
| What are natural killer (NK) cells? |
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Definition
| They are cytotoxic lymphocytes , though they are not T cells. |
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Term
| What are antigen-presenting cells (APCs)? |
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Definition
| Cells that take up the antigen, partially digest it and present a peptide fragment of the antigen (coupled to MHC proteins) to appropriate receptors on T lymphocytes |
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Term
| Name the antigen-presenting cells. |
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Definition
Dendritic cells in the lymph nodes & spleen
Langerhans cells in the skin
Macrophages
B cells |
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Term
| What are the Major Histocompatibility Complex (MHC) genes? |
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Definition
| They are the genes located on the short arm of chromosome 6 that code for the human leucocyte antigens (HLA). |
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Term
| How are the MHC proteins or HLAs classified? |
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Definition
Class I MHC proteins that are found on all nucleated cells
Class II MHC proteins that are present in antigen-presenting cells (including B lymphocytes) and in activated T cells |
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Term
| How are T lymphocytes activated by antigen-presenting cells? |
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Definition
| The MHC protein is coupled to an antigenic fragment and presented on the surface of the APC. Helper T cells bind MHC II proteins (CD4 facilitates he binding) while cytotoxic T cells bind MHC I proteins (CD8 facilitates the binding). This immunological synapse permits T cell activation. |
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Term
| Which cytokine promotes proliferation of the activated T cells? |
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Definition
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Term
| How are B cells activated? |
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Definition
| B cells can directly bind to the appropriate antigen but T helper 2 cells are required for full antibody response. |
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Term
| What is the role of antibodies in the immune response? |
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Definition
They neutralize some toxins.
They block attachment of some viruses and bacteria to cells
They opsonize bacteria.
They can activate the complement system. |
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