E2 U3 Adaptive Imm

Exam Overview

  • Exam 2 Focusing on Lymphatic & Immune Systems and Adaptive Immunity

Adaptive Immunity

  • Definition: Adaptive (Acquired) Immunity is a defense system that evolves over time with exposure to various antigens.

  • Components: Involves both antibody-mediated immunity (B cells) and cell-mediated immunity (T cells).

Characteristics of Adaptive Immunity

  1. Specificity: Highly targeted response to specific antigens.

  2. Memory: Rapid response to previously encountered antigens.

  3. Regulation: Contains mechanisms to avoid harmful responses.

  4. Tolerance: Ability to distinguish between self and foreign antigens.

Types of Adaptive Immunity

Active Immunity

  • Natural Active Immunity: Exposure to antigens through infection leading to memory.

  • Artificial Active Immunity: Vaccination exposes the individual to antigens to generate a response.

Passive Immunity

  • Natural Passive Immunity: Antibodies transferred from mother (e.g., breastmilk).

  • Artificial Passive Immunity: Antibodies received through medical treatment.

Vaccines

Types of Vaccines

  1. Attenuated Vaccines: Live microbes with reduced virulence.

  2. Inactivated Vaccines: Chemically killed microbes.

  3. Subunit Vaccines: Portions of the microbe.

  4. mRNA Vaccines: New generation of subunit vaccines.

Antibodies

Structure and Function

  • Composed of heavy and light chains forming a "Y" shape.

  • Variable Region: Determines specificity for antigens.

  • Constant Region: Determines the antibody's function.

Classes of Antibodies

  • IgG: Most abundant; crosses placenta.

  • IgA: Found in secretions; provides mucosal immunity.

  • IgM: First antibody produced; excellent in agglutination.

  • IgD: Functions mainly as a receptor on B cells.

  • IgE: Involved in allergic reactions and defense against parasites.

Effector Functions of Antibodies

  1. Neutralization of pathogens.

  2. Immobilizing pathogens.

  3. Agglutination of cells.

  4. Precipitation of soluble antigens.

  5. Enhancing phagocytosis.

  6. Activating the complement system.

Lymphocytes in Adaptive Immunity

B Cells

  • Produce antibodies; exist as plasma and memory B cells.

T Cells

  • Comprised of Helper T cells (TH) and Cytotoxic T cells (TC).

  • TH cells activate other immune cells, while TC cells kill infected cells.

Clonal Selection and Memory

  • Clonal Selection: Each lymphocyte responds to one specific antigen.

  • Memory Cells: Long-lived cells that respond faster upon subsequent exposure.

Cooperation Between Innate and Adaptive Immunity

  • Role of antibodies, phagocytosis, and interleukins in enhancing immune response.

Study Resources

  • Practice sheets and review materials available on D2L.

  • Suggested readings and educational videos to reinforce understanding.