Innate and Adaptive Immunity Overview

Innate Immunity

• Innate immunity is the body's first line of defense against pathogens.
• Physical barriers like skin and mucous membranes prevent pathogens from entering the body.
• Complement system is a group of proteins that work together to lyse pathogens, opsonize them for phagocytosis, and recruit immune cells.
• Phagocytes like neutrophils, macrophages, and dendritic cells engulf and destroy pathogens.
• Memory B cells are a component of adaptive immunity, not innate immunity.

Adaptive Immunity

• Adaptive immunity provides a more specific and targeted response to pathogens.
• Specificity means that each immune response targets a specific antigen.
• Memory allows the immune system to mount a faster and more effective response upon re-exposure to the same antigen.
• Diversity allows for a wide range of responses to different antigens.
• Immediate response is a characteristic of innate immunity, not adaptive immunity.

T Cell Education

• Thymic education is the process by which T cells learn to distinguish self from non-self antigens in the thymus.

Antigen Presentation

• Major Histocompatibility Complex (MHC) II molecules present antigens to CD4+ T cells.
• MHC I molecules present antigens to CD8+ T cells.

Immune Cell Functions

• B lymphocytes are responsible for antibody production.
• T helper cells activate and regulate other immune cells.
• Cytotoxic T cells directly kill infected or abnormal cells by releasing cytotoxic substances.
• Neutrophils are involved in phagocytosis of pathogens.
• Dendritic cells are professional antigen-presenting cells that activate naive T cells.
• Macrophages are phagocytic cells that engulf and destroy pathogens, present antigens, and secrete cytokines.

Immune Responses

• Clonal selection is the process by which lymphocytes capable of responding to a specific antigen proliferate and differentiate into effector cells.
• Immunological memory is the ability of the immune system to respond more quickly and effectively to a pathogen it has encountered before.
• Interferons are cytokines that are produced by cells in response to viral infections.
• Lymphatic system is responsible for transporting lymph, filtering pathogens, and maturation of lymphocytes.

Vaccination

• Recombinant vaccines are made by inserting the gene for a pathogen's antigen into another organism.
• Vaccines help to stimulate the adaptive immune system and develop immunity against specific pathogens.

Antibodies

• IgM antibodies are the first type of antibody produced in a primary immune response and are restricted to the circulation.
• IgA antibodies are found in secretions and provide mucosal immunity.
• IgG antibodies are the most abundant in serum and can cross the placenta.

Immune Processes

• Diapedesis is the movement of white blood cells through blood vessel walls.
• Somatic hypermutation is a process that increases the diversity of antibody responses.
• Isotype switching is the process by which B cells switch from producing one type of antibody isotype to another.

Hypersensitivity Reactions

• Hypersensitivity reactions are exaggerated immune responses to antigens.

Autoimmune Diseases

• Autoimmune diseases occur when the immune system attacks the body's own tissues.

Cytokines

• Cytokines are signaling molecules that regulate immune responses and mediate inflammation.

Immune Cells and Processes (Continued)

• Eosinophils are involved in defense against parasitic infections.
• Natural killer (NK) cells kill virus-infected and tumor cells.
• Follicular dendritic cells retain and present antigens to B cells.
• NETosis is the process by which neutrophils release DNA and proteins to form extracellular traps (NETs) to trap pathogens.

Lymphatic System and Tissues

• Spleen filters blood-borne pathogens and stores platelets.
• Thymus is the site of T cell maturation.

Immune Tolerance

• Immunological tolerance is the ability of the immune system to avoid reacting to self-antigens.
• Regulatory T cells suppress immune responses and help maintain tolerance to self-antigens.

Antigen Processing

• Antigen processing is the breakdown of antigens into peptides.

Immune System Responses

• Acute phase response is a rapid and innate immune response characterized by fever, increased vascular permeability, and production of acute phase proteins.
• Invariant natural killer T (iNKT) cells are a type of T cell that recognize lipid antigens.

Explore the differences between innate and adaptive immunity in this informative quiz. You'll learn about the body's first line of defense, the role of phagocytes, and the specific responses of adaptive immunity. Test your knowledge on key concepts like memory, specificity, and the complement system.