Ch1pp3-4

Autoimmune Diseases and Immune System

• Autoimmune diseases are characterized by an immune response against the body's own tissues and cells.

Immune System Basics

• The basis of nonreactivity in the immune system is tolerance, which prevents the immune system from reacting to the body's own tissues and cells.

Chronic Inflammatory Diseases

• Successful treatments for chronic inflammatory diseases are targeted to specific components of the immune system, such as cytokines, chemokines, and immune cells.

COVID-19

• Cytokine storm, which is an overactive immune response, contributes significantly to morbidity in COVID-19.

Types of Immunity

• Innate immunity is always present in healthy individuals and provides the first line of defense against infections.
• Adaptive immunity, on the other hand, requires proliferation and differentiation of lymphocytes in response to microbes.

Immunologic Memory

• The term used to describe the phenomenon of immunologic memory is anamnestic response.

Initial Defense Against Infections

• The innate immune system, which includes physical and chemical barriers, provides the initial defense against infections.

Eradicating Intracellular Microbes

• Cytotoxic T cells and macrophages are responsible for eradicating intracellular microbes.

Innate Immunity

• Neutrophils and natural killer cells are activated immediately after infection and before 12 hours as part of innate immunity.

Adaptive Immunity

• The adaptive immune response takes a few days to develop.

Enhanced Responses

• The term used to describe the enhanced responses seen upon repeat exposures to the same microbe is anamnestic response.

Recognition of Microbes

• Pattern recognition receptors (PRRs) recognize a limited number of molecular structures shared by classes of microbes.

Adaptive Immune Responses

• Recognition of pathogen-associated molecular patterns (PAMPs) by PRRs is required to initiate adaptive immune responses against infectious agents.

Effector T Cells

• Naive T cells lead to the formation of effector T cells after day 3 as part of adaptive immunity.

Antigens

• Antigens are molecules produced by microbes and noninfectious molecules that are specifically recognized by lymphocytes or antibodies.