| A | B |
|---|
| Opsonization | –" tagging" noself particles withso they are more readily recognized by phagocytes |
| Neutralization – | Abs fill the surface receptors on a virus or the active site on a microbial enzyme to prevent it from attaching |
| Agglutination | – Ab aggregation; particles turn into large clumps |
| Complement fixation | classical complement pathway can result in the specific rupturing of cells and some viruses |
| Precipitation | - Aggregation of particulate antigen |
| Primary Response to Antigen | immune response slow to respond because no memory cells |
| Secondary Response to Antigen | after 2nd contact with same Ag, memory cells react faster immune response |
| apoptosis | genetically programed cell death |
| Cell-mediated immunity | requires the direct involvement of T lymphocytes |
| cytokines | trigger other cells to react to nonself--raise alarm |
| B cells can act directly on an antigen T cells can only act on an antigen __________ | presented by another cell |
| T cell receptors (TCRs) | because they are receptors for antigens The receptors are in or on the T cell |
| T helper cells (CD4 or TH) | most prevalent type of T cell; regulate immune reaction to antigens, also involved in activating macrophages and increasing phagocytosis |
| Cytotoxic T cells (CD8 or TC) | destroy foreign or abnormal cells by secreting perforins that lyse cells |
| Natural killer cells | lack specificity; circulate through the spleen, blood, and lungs; kills cells that fail to present MHC I (e.g. foreign cells or cancerous cells) |
| Superantigens | are a form of a virulence factor |
| B-cell maturation | Mature in bone marrow--Millions of distinct B cells develop and “home” to specific sites in the lymph nodes, spleen, and GALT---- Come into contact with antigens throughout life--- Have immunoglobulin as surface receptors for antigens |
| T-cell maturation | Immature T-cells produced in bone marrow----- Maturation is directed by the thymus gland and its hormones-- |
