Adaptive (Acquired) Immunity

Adaptive (Acquired) Immunity: A Tailored Defense_

Adaptive immunity is a specific, targeted defense against pathogens, developed after exposure to an antigen. It involves the activation of immune cells, production of antibodies, and immunological memory.

Components of Adaptive Immunity:_

1. T Cells (T Lymphocytes): Recognize and respond to antigens presented by antigen-presenting cells (APCs).

2. B Cells (B Lymphocytes)_: Produce antibodies to neutralize or remove pathogens.

3. Antigen-Presenting Cells (APCs): Process and present antigens to T cells.

4. Major Histocompatibility Complex (MHC): A group of genes that help T cells recognize antigens.

5. Immunoglobulins (Antibodies): Proteins produced by B cells to neutralize or remove pathogens.

6. T Cell Receptors (TCRs): Molecules on T cells that recognize antigens.

7. B Cell Receptors (BCRs): Molecules on B cells that recognize antigens.

Functions of Adaptive Immunity:

1. Antigen Recognition T cells and B cells recognize specific antigens.

2. Activation of Immune Responses Activated T cells and B cells coordinate an immune response.

3. Antibody Production: B cells produce antibodies to neutralize or remove pathogens.

4. Immunological Memory: Activated T cells and B cells remember specific antigens, enabling a rapid response upon re-exposure.

5. T Cell Activation T cells become activated to coordinate an immune response.

6. B Cell Activation: B cells become activated to produce antibodies.

Types of Adaptive Immune Responses:

1. Cell-Mediated Immunity: T cells directly attack infected cells or produce chemical signals to activate other immune cells.

2. Humoral Immunity: B cells produce antibodies to neutralize or remove pathogens.

3. Mixed Immunity: A combination of cell-mediated and humoral immunity.

Diseases Related to Adaptive Immunity:

1. Immunodeficiency Disorders: Defects in adaptive immune cells or functions can lead to increased infections.

2. Autoimmune Disorders Overactive or misdirected adaptive immune responses can contribute to conditions like rheumatoid arthritis or lupus.

3. Cancer: Adaptive immune cells can recognize and eliminate tumor cells.

4. Allergies: Overactive adaptive immune responses can contribute to allergic reactions.

5. Transplant Rejection: Adaptive immune cells can reject transplanted organs.

Interesting Facts:

1. Adaptive immunity takes time to develop, whereas innate immunity provides immediate protection.

2. Adaptive immune cells can remember specific pathogens, enabling a rapid response upon re-exposure.

3. Vaccines exploit adaptive immunity to provide long-term protection against specific pathogens.

4. Immunotherapy harnesses adaptive immunity to fight cancer and other diseases.

5. Adaptive immunity can be influenced by genetics, environment, and lifestyle factors.