Exam 1: Immune/Inflammatory response

Question 1

What is the purpose of the immune system?

Answer 1

• Neutralize, eliminate, or destroy microorganisms that invade the body
• To recognize and eliminate aberrant cells (i.e. cancer)

Question 2

Differentiate self vs non self—why is this important?

Answer 2

• Immune system cells only mount a response against cells determined to be “non-self”
o Cells different from a person’s own healthy cells
• Self-tolerance: the ability of cells to recognize self vs non-self

Question 3

What are the main cells of the immune system?

Answer 3

• Leukocytes (WBCs)
o Neutrophils, Eosinophils, Basophils, Macrophages & Monocytes, Dendritic cells, NK cells, T cells, Cytokines, B cells, Complement

Question 4

What factors influence the immune system?

Answer 4

• Nutritional status
• Environmental conditions
• Medications
• Presence of diseases
• Age

Question 5

What are the three processes involved in immunity? Which are specific vs nonspecific

Answer 5

• Nonspecific
o Inflammation

• Specific
o Antibody-mediated (humoral) immunity
o Cell-mediated immunity

Question 6

What are the components of the immune system

Answer 6

•	Skin and mucous membranes 
•	Mononuclear phagocyte system
•	Lymphoid system
o	Spleen, thymus gland, and lymph nodes 
•	Bone marrow

Question 7

Identify the cells of the immune system: lymphoid

Answer 7

B cells
• Major cells of antibody-mediated immunity
• Able to produce antibodies
• Require help from T helper cells to respond
T cells
• Major cells of cell-mediated immunity
• T-helper cells (CD4+)
• Interact with antigens
• Secrete cytokines that stimulate B-cell proliferation and antibody production
NK cells
• Innate immune cells
• Can kill tumor cells and virally infected cells without previous exposure

Question 8

Identify the cells of the immune system: myeloid

Answer 8

RBCs
• Erythrocytes, deliver oxygen to the tissues, iron rich hemoglobin binds to oxygen
Monocyte
• Immature macrophages
• Circulate in the blood stream for about 3 days prior to entering tissue and becoming macrophage
• Macrophages
o Called different cells in different tissue
o Life span from months to years
o Functions
 Phagocytosis
 Repair of injured tissue
 Antigen processing (CD4+)
 Secretion of cytokines to help control the immune system
Granulocytes
• Neutrophils
o 60-80% total
o Stem cells – mature in bone marrow
o Mature: segmented neutrophils (segs)
o Immature: (bands)
o 1st responder to infection
o No energy reserve (6 hour life span)
o Only mature form (segs) capable of phagocytosis
o Produce potent chemical mediators that enable them to destroy microorganisms
• Eosinophils
o Allergic reactions and infection by intestinal parasites
o Release inflammatory chemicals in areas of inflammation
o Primary function to kill parasitic helminths (worms)
• Basophils
o Release vasoactive substances (heparin, histamine) during inflammation
o Also involved in wound healing

Question 9

Why are neutrophils important?

Answer 9

1st responders to infection

Question 10

What are macrophages and why are they important?

Answer 10

• Carry out phagocytosis to destroy foreign invaders

Question 11

What is complement?

Answer 11

• 20 plasma proteins that interact in a cascade fashion to produce important mediators of inflammation and immunity
• Can be activated by microbial agents (alternative pathway) or by antigen-antibody complexes (classical pathway)

Question 12

What is the process of inflammation?

Answer 12

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Question 13

What are the clinical manifestations; local and systemic

Answer 13

•	Systemic
o	Fever 
o	Neutrophilia (increased WBC) 
o	Lethargy 
o	Malaise
o	Increased acute phase proteins (CRP)
o	Increased erythrocyte sedimentation rate (ESR or sed rate) 
•	Local
o	Redness, swelling, heat, pain

Question 14

What cells are important to the process?

Answer 14

• Neutrophils, eosinophils, NK cells, macrophages

Question 15

Identify nonspecific vs specific components of the immune system

Answer 15

• Specific adaptive immunity
o Acquired through previous exposure to infectious and other foreign agents
o Destroy specific foreign agents based on their distinct antigenic properties
o Recognizing foreign invaders, destroying them, and retaining a memory of the encounter such that an even more effective defense (adaptive) will be achieved upon subsequent exposure
o B and T lymphocytes are mediators
o B cells “humoral” immunity because the antibodies they produce are found in body fluids
o T cells produce cell mediated because they recognize antigens
• Nonspecific innate immunity
o Cellular and biochemical defenses that are in place before an encounter with an infectious agent
o Provide rapid protection
o Able to distinguish between self and non-self but not specific agents
o Major components
 Epithelial cells: block entry and secrete antimicrobial enzymes
o Phagocytic neutrophils and macrophages
 Engulf and digest microbes
o Dendritic cells (DCs)
o NK cells
 Kill intracellular microbes and foreign agents
o Complement system
 Amplifies the inflammatory response

Question 16

Where do B and T cells mature?

Answer 16

• B cells – bone marrow and lymph tissues

* T cells – thymus

Question 17

What is the MHC?

Answer 17

• Cluster of genes on chromosome 6
• Also known as human leukocyte antigen (HLA) complex
• Proteins made by these genes are displayed on the surface of body cells and mark them as “self”

Question 18

Describe the process of antibody mediated immunity listing the main cells involved

Answer 18

• Memory B cells
o Contain antigen receptors and function in manner similar to memory T
o When exposed to the same type of antigen, respond rapidly with antibodies
• Plasma cells
o Short-lived antibody producing factories
o Have receptors on their surfaces that can bind antigens
o Each B cell binds only one particular antigen
• Long lasting immunity possible

Question 19

What happens during and antibody-antigen interaction?

Answer 19

• Antibodies are proteins that specifically bind a particular antigen
• Antibodies have several functions
o Precipitation
o Agglutination: form large insoluble complex
o Neutralization: toxins bound or inactivated before they can interact with cells
o Opsonization: foreign antigen is coated making it more recognizable to phagocytic cells (happens in the spleen)
o Complement activation

Question 20

How is immunity achieved?

Answer 20

• B and T cell functions are interdependent
• T cells cannot respond to soluble antigens
• On first exposure, B cells are minimally activated by antigen unless they are stimulated by cytokines from T cells
• Immunity = state of resistance against infection from a particular pathogen
• Provided primarily by adequate levels of circulating antibodies

Question 21

What are the 5 immunoglobulins and where are they found

Answer 21

•	IgG 
o	Most common
o	Complement, crosses placenta 
•	IgM 
o	Activates complement 
o	ABO incompatibility (blood typing) 
•	IgA 
o	Secretions (mucus, saliva, tears, breast milk) 
•	IgD 
o	Stimulates B cells to multiply and mature 
•	IgE 
o	Parasites and respiratory infections 
o	Hypersensitivity reactions

Question 22

What is innate vs adaptive immunity?

Answer 22

• Innate (natural) – in place before encounter, not specific
• Adaptive (acquired) – through previous exposure, specific

Question 23

What is Active vs passive immunity?

Answer 23

•	Active 
o	Acquired through actually having the disease 
o	Antigen enters the body and antibodies are created against it 
o	Natural active
	Person has disease 
	Most effective and longest lasting 
o	Artificial active 
	Small amount of antigen introduced 
	Vaccinations, may require boosters 
•	Passive 
o	Temporary type transferred (in utero, breast milk) 
o	Antibodies introduced into the body 
o	Natural passive 
	Mother to fetus across placenta 
o	Artificial passive 
	Antibodies injected 
	When person is exposed to a serious disease and has no known actively acquired immunity
	Rabies, snake bite, tetanus

Question 24

Define this alteration in immune function: autoimmunity

Answer 24

• Inappropriate immune response; lack of differentiation of self
• Body attacks own tissue
o Recognizes self-cells as foreign and mounts an immune response that injures self-tissue
• Polygenic and multifactorial

Question 25

Define this alteration in immune function: hypersensitivity

Answer 25

• Exaggerated or inappropriate response to specific antigens; overresponsiveness

Question 26

•Define this alteration in immune function: immunodeficiency

Answer 26

* Lack of a response by a component of the immune system | * Due to missing component, damaged component, or missing step in parts of the immune system

Question 27

Define this alteration in immune function: malignancy of WBC's

Answer 27

• Cancer of WBCs (Leukemia, lymphoma, plasma cell myeloma)

Question 28

Know the four types of hypersensitivities, patho and examples

Answer 28

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Question 29

Primary immunodeficiencies patho | IGA disorder

Answer 29

* Most common * Familial, resulting in no circulating or secretory levels of IgA * May be acquired, caused by medications or various diseases * Chronic infections of the sino-pulmonary tract, GI tract, and GU tract * Treatment: treat infections w/ antibiotics

Question 30

Primary immunodeficiencies patho: Bruton X-Linked

Answer 30

* Males, females are the carriers * Immature B-cells unable to produce antibodies * Decreased IgG, IgM, and IgA * No apparent health problems until 4-5 months (protected by IgG from mother) * Recurrent infections: ear infections, dermatitis, pharyngitis, bronchitis, pneumonia, etc * Treatment: Antibiotics (chronic, low-dose), IV Ig (passive immunity w/ antibodies

Question 31

Primary immunodeficiencies patho: DeGeorge's syndrome

Answer 31

* Lack of development of thymus gland’ aplastic (doesn’t work) or hypoplastic (reduced function) * T cells can’t mature * Congenital (random mutational event) * Associated with other developmental disorders: heart defects, hypoparathyroidism  hypocalcemia (tetany) * Severe recurrent infections: viral, fungal, protozoan, and bacterial * B-cell levels may be normal, but may have abnormal antibody response due to decreased helper T cells * Treatment: antibiotics/anti-infectives

Question 32

Chronic Mucocutaneous Candidiasis

Answer 32

• Autosomal recessive causing selective T-cell response o Normal T-cell response to non-fungal pathogens o Cannot respond to Candida • Normal antibody responses • Accompanied by endocrine dysfunction, parathyroid and adrenal glands

Question 33

SCID

Answer 33

* Severe Combined Immune Deficiency Syndrome * Inherited X-linked * No immune system: lack B and T cells * Severe recurrent infections and/or neoplasms * Cannot live outside sterile environment * Treatment: bone marrow transplant or gene therapy

Question 34

Define HIV, what is the patho, and define the cells primarily infected

Answer 34

• Human immunodeficiency virus • AIDS = Acquired immunodeficiency syndrome • Defective cell-mediated immunity, especially decrease of CD4 or helper T cells • Caused by retrovirus • Retroviruses infect human cell and reverse transcriptase (enzyme) forces human DNA to use viral RNA • This new DNA is incorporated into the human cell’s DNA and is now template for viral replication • HIV attaches to and infects helper T cells and macrophages • At risk for opportunistic infections and tumor formation • Found in all body fluids, transmitted through blood, semen, vaginal/cervical secretions, amniotic fluid, and breast milk • Classification based on CD4 counts o >500 ul o 200-400 ul o