Exam 4

Chapters 14, 15, 16, & 18

Bacteremia

Presence of bacteria in the blood

Bioburden

The number of microorganisms found in a pharmaceutical product or in a body part

Blood-Brain Barrier

A selectively permeable membrane made up of tightly packed capillaries that supply blood to the brain and spinal cord. Large molecules and most pathogens cannot permeate the narrow spaces. Fat-soluble (lipophilic) molecules and oxygen can dissolve through the capillary cell membranes and are absorbed into the brain

Cytokine

Any of the group of small signaling proteins secreted by human cells that bind to receptors on endothelial and immune system cells, alterine the behavior of those cells

Dysbiosis

An imbalance in the composition of a microbiome that can be brought on by stress or antibiotic therapy. It may cause some human diseases or even influence behaviors

Enterotoxin

A toxic protein, made by microbes, that damages the intestine of the host and causes diarrhea and / or vomiting; produced by some gram-negative and gram-positive pathogens

Epidermis

The outer protective cell layer in most multicellular animals

Fecal Microbiota Transplant (FMT)

Transfer of the intestinal microbiome of a healthy donor to a patient suffering from a severe intestinal disease

Gnotobiotic Animal

An animal that is germ-free or colonized by a known set of microbes

Immunocompromised Host

An animal with a weakened immune system

Immunomodulin

A protein made by normal microbiota that influences the host immune response by modifying the secretion of host proteins, such as cytokines

Metagenomic Study

An analytical method that uses DNA sequencing to identify all the organisms directly from an environmental sample

Microbiome / Microbiota

The total community of microbes associated with an organism (such as the human body) or with a defined habitat (such as soil or plants)

Mucociliary Escalator

The ciliated mucous lining of the trachea, bronchi, and bronchioles that sweep foregin particles up and away from the lungs

Nasopharynx

The passage leading from the nose to the oral cavity

Opportunistic Pathogen

A microbe that normally is not pathogenic but can cause infection or disease in an immunocompromised host organism

Oropharynx

The are between the soft palate and the upper edge of the epiglottis

Petechial Rash

Tiny red spots on the skin that do not blanch when pressed

Prebiotic

A food or nutritional supplement that is ingested to improve health by providing fibers that can be digested by beneficial bacteria

Probiotic

A food or nutritional supplement that contains live microorganisms and is ingested to improve healthy by promoting benficial bacteria

Virome

All the viruses that inhabit a particular organism or environment

Adaptive Immunity

Immune responses activated by a specific antigen and mediated by B cells and T cells

Antibody

A host defense protein (a type of immunoglobulin), produced by differentiated B cells, that binds to a specific antigen

Antibody-Dependant Cell-Mediated Cytotoxicity (ADCC)

The process by which natural killer cells destroy viral protein-expressing, antibody coated host cells

Antigen

A compound, recognized as foreign by the cell that elicits an adaptive immunity response

Antigen-Presenting Cell (APC)

An immune cell that can process antigens into epitopes and display those epitopes on the cell surface for recognition by naive T cells

Apoptosis

Programmed cell death of eukaryotic cells

Basophil

A white blood cell that stains with basic dyes and secretes compounds that aid innate immunity

B Cell

An adaptive immune cell that develops in the bone marrow and gives rise to antibody-producing plasma cells. Along with T cells, they are antigen-specific cells that mediate or regulate the adaptive immune response.

Bradykinin

A cell signaling molecule that promotes extravasation, activates mast cells and stimulates pain perception

Chemokine

Any of a group of proteins, produced by damaged or infected tissues, that stimulate the migration of white blood cells toward the site of infection

Complement

Innate immunity proteins in the blood that from holes in bacterial membranes, killing the bacteria. Some omponents attract phagocytes; others can coat bacteria and promote phagocytosis

C-reactive Protein (CRP)

A protein that stimulates the complement cascade; it is induced in the liver by cytokines. Elevated levels in the blood are associated with inflammation of any kind, including infection

Defensin

A type of small, positively charged peptide, produced by animal tissues, that destroys the cell membranes of invading microbes

Dentritic Cell

An antigen-presenting white blood cell that primarily takes up small soluble antigens from its surroundings

Eosinophil

A white blood cell that stains with the acidic dye eosin and secretes compounds that facilitate innate immunity

Extravasation

The movement of white blood cells out of blood vessels and into surrounding infected tissue

Factor H

A normal serum protein that prevents the inadvertent activation of complement in the absence of infection

Granuloma

A thick lesion formed around a site of infection

Gut Associated Lymphoid Tissue (GALT)

Lymphoid tissues, such as tonsils and adenoids, that are found in conjuction with the gastrointestinal tract and contain immune cells

Immune System

An organism’s cellular defense system against pathogens

Innate Immunity

Also called nonadaptive immunity. The system of nonspecific mechanisms that the body uses for protecting against pathogens

Integrin

Any of a family of host cell membrane proteins that mediate adhesion of cells to one another and to the extracellular matrix

Interferon

Any of a family of cytokines that inhibit viral replication

Interleukin 1 (IL-1)

A cytokine released by macrophages

Langerhans Cell

A specialized, phagocytic dendritic cell that is the predominant cell type in skin-associated lymphoid tissue

Lymph

Interstitial fluid and white blood cells (including macrophages)

Lymph Node

A secondary lymphoid organ, formed by the convergence of lymphatic vessels, where antigen-presenting cells and lymphocytes interact

Lysozyme

A hydrolytic enzyme, secreted by eukaryotic cells, that degrades bacterial cell wall peptidoglycan

Macrophage

A mononuclear, phagocytic, antigen-presenting cell of the immune system that is found in tissues

Major Histocompatibility Complex (MHC)

Transmembrane cell proteins important for recognizing self and for presenting foreign antigens to the adaptive immune system

Mast cell

A white blood cell that secretes proteins that aid innate immunity. Mast cells reside in connective tissues and mucosa and do not circulate in the bloodstream M

M Cell

A specialized epithelial cell (microfold cell) with Peyer’s patches lining the intestine; M cell transport antigens and microbes from the intestines across the epithelial barrier to macrophages

Microbe-Associated Molecular Pattern (MAMP)

Molecules associated with groups of microbes, both pathogenic and nonpathogentic, that are recognized by cells of the innate immune system

Monocyte

A white blood cell with a single nucleus that can differentiate into a macrophage or a dendritic cell

Mononuclear Phagocyte System (MPS)

A collection of cells that can phagocytose and sequester extracellular material

Mucosa Associated Lymphoid Tissue (MALT)

A system of concentrated sites of lymphoid tissue closely associated with mucosal surfaces, whoe function includes surveying the antigens and pathogens that pass through the mucosae

Natural Killer (NK) cells

A lymphocyte that kills some tumor cells and cells infected with a virus or bacteria; an importnat component of innate immunity

Neutrophil

A white blood cell of the innate immune system that can phagocytose and kill microbes

NOD-like receptor (NLR)

A eukaryotic cytoplasmic protein that recognizes particular microbe-associated molecular patterns present on microorganisms

Opsonization

The process of coatin pathogens with IgG antibodies or complement to facilitate phagocytosis

Oxidative Burst

A large increase in the oxygen consumption of immune cells during phagocytosis of pathogens as the immune cells produce oxygen radicals to kill the pathogen

Pattern Recognition Receptor (PRR)

A receptor on a cell fo the innate immune system that recognizes common molecular patterns on microbial surfaces

Perforin

A cytotoxic protein, secreted by cytotoxic T cells and natural killer cells, that froms proes in target cell membranes

Peyer’s Patches

An aggregation of lymphoid tissue found in the lower small intestine

Phagocytosis

A form of endocytosis in which a large extracellular particle is brought into the cell

Phagosome

A large intracellular vesicle that forms as a result of phagocytosis

Polymorphonuclear Leukocyte (PMN)

Aslo called granulocyte. A white blood cell with a multilobed nucleus and cytoplasmic granules. PMNS are classified as neutrophils, basophils and eosinophils

Pyrogen

An substance that induces fever

Selectin

Any of a family of cell adhesion molecules

Sepsis

Also called blood poisoning. A systemic inflammatory response that is triggered by an infection and is so extreme that it can kill the patient

Skin-Associated Lymphoid Tissue (SALT)

Immune cells, such as dendritic cells, located under the skin that help eliminate bacteria that have breached the skin’s surface

T Cell

Also called T Lymphocyte. An adaptive immune cell that develops in the thymus and can give rise to antigen-specific helper T cells and cytotoxic T cells

Toll-Like Receptor (TLR)

Any of a family of eukaryotic transmembrane glycoproteins that recognize a particular microbe-associated molecular pattern present on pathogenic microorganisms

Tumor Necrosis Factor Alpha (TNF-a)

A cytokine involved in systemic inflammation

Vasoactive FActor

A cell signaling molecule that increase capillary permeability

Vasodilation

Widening of blood vessels

White Blood Cell (WBC) Differential

A laboratory test that counts the types of white blood cells in a patient’s blood

Affinity Maturation

The process by which the antigen-binding site of an antibody population gains increased affinity for its target antigen or epitope during an adaptive immune response

Allotype

An amino acid difference in the antibody constant region that distinugishes individuals within a species

Antigenicity

Also called immunogenicity. A measure of the effectiveness of an antigen in eliciting an immune response

Attenuated

Referring to live but crippled pathogens. Attenuated vaccines contain crippled viruses or bacteria that are injected into a host to stimulate an adpative immune response

B-Cell Receptor (BCR)

A B-cell membrane protein complex containing an antibody in assoication with the proteins Iga and Igb

Bone Marrow Transplant

A medical procedure in which a person’s bone marrow is destroyed and then replaced with bone marrow that contains healthy stem cells for the proper production of lymphocytes and other blood cells

Capping

The clustering of B-cell receptor molecules at one pole of a B cell after receptors have been cross-linked by antigens or epitopes

Cell Mediated Immunity

Also called cellular immunity. A type of adaptive immunity employing mainly T-cell lymphocytes

Class I MHC Molecule

Any of a class of surface proteins, found on all nucleated cells of the human body (absent from RBCs and platelets), that present cytoplasmically synthesized foreign antigen epitopes to cytotoxic T cells

Class II MHC Molecule

Any of a class of surface proteins, found on antigen-presenting cells (dendrititic cells, macrophages, and B cells), that present phagocytosed foreign antigen epitopes to helper T cells

Clonal Selection

The rapid proliferation of a subset of B cells during the primary or secondary antibody response

Constant Region

The region of an antibody that defines the class of a heavy chain (isotype) or light chain

Cytokine Storm

A massive production of cytokines leading to excessive tissue damage, inflammation, and shock

Cytotoxic T Cell (Tc Cell)

A T cell that expresses CD8 on its cell surface, binds MHC I-presented epitopes, and can secrete toxic proteins such as perforin and granzymes. Once activated Tc cells are known as activated cytotoxic T lymphocytes, or CTLs

Epitope

Also called an antigenic determinant. A small segment of an antigen that can elicit an immune response. An antigen can have many epitopes

F(ab)2 Region

The two linked antigen-binding arms of an antibody molecule

Fc Region

The region of an antibody that binds to specific receptors on host cells in an antigen-independent manner. It is found in the carboxy-terminal “tail” region of the antibody

Hapten

A small compound that must be conjugated to a larger carrier antigen in order to elicit and antibody response

Heavy Chain

The larger of the two protein types that make up an antibody. Each antibody contains two heavy chaing and two light dish

Helper T Cells

A T cell that expresses CD4 on its cell surface and secretes cytokines that modulate B-cell isotope, or class, switching

Humoral Immunity

A type of adaptive immunity mediated by antibodies

Idiotype

A difference in amino acid sequence, usually in the antigen-binding site of an antibody, that. distinguishes different antibodies within any isotype class of antibodies in an individual.