Test 5 Serology/ Immunology

Serology

study of antiserum or serum and antibodies in a physiological fluid

Serum

straw-colored fluid laking coagulation factors

after clot formation, it can be decanted or aspirated for use in testing

contains antigens and antibodies

Precipitation

visual aggregation of soluble test antigens with antibodies

Agglutination

visual aggregation of particulate test antigens

Immunoassays

methods involving the detection of antigen-antibody interactions using label molecules

True or False

Peripheral blood is used in most serological diagnostic studies

True

Blood plasma make up ___ of total extracellular fluid in body.

a. 1/8

b. 1/5

c. ¼

d. ½

c. ¼

Blood plasma contains:

cells, proteins, and metabollites

other body fluids tested for antigens and antibodies:

CSF, amniotic fluid, urine, bone marrow, and seminal/ vaginal fluids

Immunophenotyping

study of surface markers that differentiate one immune cell from another

Leukocytes (WBC)

Lymphoids & Myeloids

Lymphoids

T-cells and B-cells

Myeloids

Neutrophil, Macrophage, Eosinophil, Mast cell

Proteins

main source of immunogenicity

represent serological diagnosis

Subcellular products:

Lipoproteins (lipids), glycoproteins (sugar), and nucleoproteins (DNA, RNA)

Titers

detection of concentration of antibody necessary to achieve an observed reaction

used as an indicator of antibody strength

Innate responses

driven by pattern recognition (PRR’s)

Adaptive responses

driven by genetic rearrangements in antibody and receptor structures associated with B and T-cells

Barrier immunity

combination of physical and biochemical protection

Physical protection

skin, oral mucosa, intestinal mucosa, respiratory mucosa

biochemical protection

tears, mucus, enzymes, Antimicrobial peptides and proteins (APP),

True or False

Organs of immune system are sites of cell development and activity

True

Cytokines

messengers that bind receptors on cell surface and initiate gene expression changes

Chemokines

soluble and insoluble molecular cues for migration

Primary lymphoid organs

Bone marrow and Thymus

Bone marrow

spongy tissue of central cavity of bone

Contain Hematopoietic stem cells

source of lymphoid precursors and B-cell development

Thymus

multi-lobed organ

contain epithelial cells and thymocytes

site of T-cell development from CLP’s

Secondary lymphoid organs

lymph-nodes, spleen, mucosa associated lymphoid organs

Myeloid cells

Granulocytes - neutrophils, eosinophils, basophils, mast cells

Monocytic cells

monocytes, macrophages, and dendritic cells (DC’s)

Lymphoid cells

T and B-cells

Neutrophils

PMN’s or segs with lobulated nuclei

engulf pathogens by phagocytosis followed by killing

Basophils

develop in bone marrow

contain histamines, enzymes and growth factors

degranulate upon activation

Eosinophils

bilobed nuclei with secretory granules

modulate function of other immune cells by chemokines (secrete growth factors and molecular cues)

Mast cells

found in tissues

contain granules

attracting and modulating cell isolation and destruction

Monocytes

circulate in blood

differentiate into macrophages and DC’s

Macrophages

large; inhabit lymphoid and non-lymphoid organs

Dendritic cells

circulate in blood; take up residence in peripheral tissues.

immune surveillance activation of adaptive immune cells.

Classical pathway

activated by antigen-antibody complexes (IgG,IgM)

C1, C2, C4, activate C3 and then C5-9

Alternative pathway

activated by certain bacterial pathogens or toxins

activate C3 then C 5-9

complement cascade pathways

lead to formation of membrane attack complex

punches holes in membrane of target cell or bacteria.

Major histocompatibility complex (MHC)

polygenic (within each person)

multiple genes encode MHC 1 and 2

True or False

Innate and Adaptive cells play key roles in determining pathogen clearence

True

pathogen proteolytic degradation leads to

peptide presentation and T-cell activation

Activated CD4 T-cells activate B-cells and CD8 T-cells which,

deliver humoral immunity and targeted cellular killing of infected cells

Key points of adaptive immune response:

ability to discriminate non-self to self

protective memory formation

clonal expansion during activation

clonal deletion during development as basis of central tolerance

Active immunity

host makes antibody against antigen

long-lasting (HEP B)

Passive immunity

performed antibody delivered to host

short-acting (mother-child)

Thymic disorders

DiGeorge syndrome- heart defects, learning difficulties, altered facial features