___________DEFENSES of the HOST: THE IMMUNE RESPONSE Chapter 17 ___________DEFENSES of the HOST: THE IMMUNE RESPONSE ______________ ANTIBODY and LYMPHOCYTE RESPONSE to an ANTIGEN

____________________ Study of the defense mechanisms against infectious agents and foreign substances Surveillance of the body Recognition of foreign material Destruction of foreign material Includes nonspecific and specific immunity Nonspecific or _______: includes 1st and 2nd line of defense Specific or ________: includes 3rd line of defense White blood cells (WBC) or leukocytes are play an important role

____________ IMMUNITIES - SPECIFIC

SUMMARY OF THE DIFFERENT ____________ IMMUNITIES

________ IMMUNE RESPONSE Adaptive Immunity Third line of Defense Specific immunity is a complex interaction of immune cells reacting against antigens _________ RESPONSE First response to Ag May take a week or more to develop __________ RESPONSE Immune system remembers pathogen on subsequent exposure Immediate response DIVIDED INTO 2 CATEGORIES Humoral Immunity -Eliminates _________cellular pathogens Cellular Immunity -Eliminates _______cellular pathogens

HUMORAL IMMUNITY production of specific _____________ against foreign substances called antigens

PROPERTIES of __________ Substances that trigger _____ production or other immune response: Antibody generator Types : Proteins, polysaccharides- induce strong immune response :Lipids, nucleic acids- weak response Recognition of antigen directed at antigenic determinant or _______ ________-specific area on Ag against which Abs are formed

OVERVIEW of ________ IMMUNITY Mediated by B lymphocytes a.k.a B cells Develops in bone marrow B cell receptors bind to Ag: triggers proliferation of B cells into _________ cells produce antibodies antibodies produced when antigen binds to B cell receptor Extracellular Antigen Memory cell Proliferation & Differentiation of Activated B Cell B Cell Activates B cells that bind Ag Plasma cell Antibody Production Ab + Ag Cellular Immunity Helper T Cell

PROPERTIES OF _____________ products of B Cell Activation PROPERTIES of B CELLS: Special group of lymphocytes Produced in bone marrow Mature B cells migrate to lymphoid organs Produce: plasma cells -produce Abs memory cells CLASSES of ANTIBODIES: 1. IgG 2. IgM 3. IgA 4. IgD 5. IgE

PROPERTIES of __ ANTIBODIES 80% of serum antibodies Also present in lymph, intestine, and tissue fluids Cross placenta Protects fetus and newborn Fix complement Enhance phagocytosis Neutralize toxins & viruses

PROPERTIES of IgA ANTIBODIES IgM ANTIBODIES PROPERTIES of IgA ANTIBODIES Protection for newborns Mucosal protection Present In secretions 10-15% of serum Abs First Ab produced in response to infection Agglutinates microbes 5-10% of serum antibodies PROPERTIES of IgD ANTIBODIES PROPERTIES of IgE ANTIBODIES On mast cells and basophils Allergic reactions Lysis of parasitic worms 0.002% of serum Abs In lymph and on B cells May act to delete defective B cells Help initiate immune response 0.2% of serum Abs

CLONAL SELECTION the proliferation of antigen-activated __ cells (form secondary response to antigen) (involved in antibody production)

CONSEQUENCES of ANTIBODY-ANTIGEN INTERACTIONS 1. ______________ Blocks adhesion of bacteria and viruses to mucosa Prevents toxin from interacting with cell 2. Immobilization and prevention of adherence Antibody bonding to cellular _______ to interfere with function 3. Agglutination and precipitation Clumping of bacterial cells by specific antibody Bacteria more easily phagocytized

CONSEQUENCES of ANTIBODY-ANTIGEN INTERACTIONS cont’d 4. Opsonization Coating of bacteria with antibody to enhance _______________ 5. ___________ (serum proteins involved with innate, non-specific immunity) Antibody bonding triggers classical pathway 6. Antibody-dependent cellular cytotoxicity Multiple antibodies bind to a cell which becomes target for certain nonspecific immune cells

RECOGNITION of SELF and NONSELF _____________ Glycoprotein receptors located on the surface of _______ cells Role: recognition Confer specificity and _________ Recognized by lymphocyte cells as “self” Lymphocytes recognize microbe receptors as “nonself” EX.: Major Histocompatability Complex CLONAL ________________ The process of destroying B and T cells that react to self as foreign Ags

CELL MEDIATED IMMUNITY SPECIFIC CELLS T ________________ Respond to _____cellular antigens Produce and respond to cytokines (chemical messengers) Subset of T cells with unique CD receptors Helper T cell/CD4 Cytotoxic T cell/CD8 NONSPECIFIC CELLS ANTIGEN PRESENTING CELLS ______________ ______________ cells NATURAL KILLER CELLS

SOME TYPES of T LYMPHOCYTES 1. ________ T CELLS Regulate immune response to antigens by releasing cytokines (chemical messengers) Cytokines activate: Other T cells, delayed type hypersensitivity) B cell production and differentiation Macrophages 2. __________T CELLS Bind and lyse cells (apoptosis) microbes, viral infected cells, foreign cells, cancer cells Mode of action ___________ production make lesions in the membrane of infected cells ___________– degrade proteins Induce target cells to undergo apoptosis

ROLE of ____ T LYMPHOCYTES IN ANTIGEN RECOGNITION AND RESPONSE T lymphocytes have multiple copies of T cell receptors Receptors have variable sites for antigen bonding T cell receptors interact directly with “presented” antigen T cell receptor does not react with free antigen Antigen must be presented by an antigen presenting cell: B cells Macrophages Dendritic cells

ACTIVATION OF __________ T LYMPHOCYTES CELLS BY T DEPENDENT AGS (CELL-MEDIATED CYTOTOXICITY)

NONSPECIFIC CELL MEDIATED IMMUNITY Activated ____________: Macrophages stimulated by ingesting Ag or by cytokines ________ Cells Present antigens Natural Killer Cells: Lymphocytes that destroy microbes, virus-infected cells, tumors

CELL COMMUNICATION IN IMMUNITY Markers: the “eyes” and “ears” of the cell Cell surface ___________ ________: the “voice” of the cell-chemical communicators Small proteins released from human cells that encounter foreign matter Two major classes of cytokines: _________ – important in control of viral infections _________ – produced by leukocytes, important in innate and adaptive immunity ___________ Molecules: the “hands” of the cell Allow cells to adhere to each other Recruit phagocytic cells to site of injury

SUMMARY OF MAJOR COMPONENTS OF ______________________