Immune Response and Inflammation

Study Notes

Innate Immunity:
- First line of defense against infection
- Includes physical barriers (skin, mucous membranes), phagocytic cells (neutrophils, macrophages), and antimicrobial peptides
Adaptive Immunity:
- Specific immune response to pathogens
- Involves activation of T-cells and B-cells
- Memory cells provide long-term immunity

Acute Inflammation:
- Rapid, short-term response to injury or infection
- Characterized by increased blood flow, swelling, heat, redness, and pain
Chronic Inflammation:
- Long-term, low-grade inflammation
- Can lead to tissue damage and disease (e.g., arthritis, atherosclerosis)

Immunodeficiency:
- Weakened immune system, making the body more susceptible to infection
- Examples: Severe Combined Immunodeficiency (SCID), HIV/AIDS
Autoimmune Disorders:
- Immune system attacks healthy cells and tissues
- Examples: Rheumatoid Arthritis, Lupus, Type 1 Diabetes
Hypersensitivity Reactions:
- Overactive immune response to harmless substances (e.g., allergies)

HIV Infection:
- Human Immunodeficiency Virus (HIV) targets and destroys CD4+ T-cells (helper T-cells)
- Weakens immune system, making the body vulnerable to opportunistic infections
AIDS (Acquired Immunodeficiency Syndrome):
- Advanced stage of HIV infection, characterized by severe immunodeficiency and opportunistic infections
- Diagnosed when CD4+ T-cell count falls below 200 cells/μL or with the presence of certain opportunistic infections

Viral Replication:
- HIV integrates into host DNA, allowing it to replicate and produce new viral particles
- Viral load increases, leading to immune system decline
CD4+ T-Cell Depletion:
- HIV targets and destroys CD4+ T-cells, impairing immune function
- Decreased CD4+ T-cell count indicates disease progression
Immune System Dysfunction:
- HIV disrupts immune cell function, leading to impaired cytokine production and immune response
- Increased susceptibility to opportunistic infections and cancers

Innate immunity is the first line of defense against infection, involving physical barriers, phagocytic cells, and antimicrobial peptides.
Adaptive immunity is a specific response to pathogens, involving T-cells and B-cells, and provides long-term immunity through memory cells.

Acute inflammation is a rapid, short-term response to injury or infection, characterized by increased blood flow, swelling, heat, redness, and pain.
Chronic inflammation is a long-term, low-grade response that can lead to tissue damage and disease.

Immunodeficiency is a weakened immune system, making the body more susceptible to infection, with examples including Severe Combined Immunodeficiency (SCID) and HIV/AIDS.
Autoimmune disorders occur when the immune system attacks healthy cells and tissues, with examples including Rheumatoid Arthritis, Lupus, and Type 1 Diabetes.
Hypersensitivity reactions are an overactive immune response to harmless substances, such as allergies.

HIV infects and destroys CD4+ T-cells (helper T-cells), weakening the immune system and making the body vulnerable to opportunistic infections.
AIDS is the advanced stage of HIV infection, characterized by severe immunodeficiency and opportunistic infections, diagnosed when CD4+ T-cell count falls below 200 cells/μL or with the presence of certain opportunistic infections.

HIV replicates by integrating into host DNA, allowing it to produce new viral particles, leading to an increase in viral load and decline of the immune system.
HIV targets and destroys CD4+ T-cells, impairing immune function and depleting CD4+ T-cell count, indicating disease progression.
HIV disrupts immune cell function, impairing cytokine production and immune response, leading to increased susceptibility to opportunistic infections and cancers.