Ch 6: Diseases of the Immune System Flashcards
1
Q
what are the three main things that make up the immune system
A
epithelial barriers, leukocytes, and proteins
2
Q
what is innate, natural, or native immunity
A
portion of the immune system that is present at birth
responds to all pathogens in the same way
dominant response for the first 12 hours of exposure
include first and second line of defense
3
Q
what is adaptive, specific, or acquired immunity
A
respond individually to unique glycoprotein markers (antigens Ag)
takes 3-5 days for the response to kick in then it becomes that dominant response
include third line of defense
4
Q
explain the first line of defense
A
surface barriers block entry of pathogens into the body
includes epithelial cells and secretory molecules
epithelial cells: skin and mucous membranes that line all open passageways into the body
secretory molecules: peptides like lysozymes, defensins, collectins, and lactoferrin
defense is constant, broadly specific, and has no memory
5
Q
explain the second line of defense
A
inflammatory response against tissue injury and infection
defense is immediate, nonspecific, and has no memory
cells and proteins involved are always in the bloodstream
cells: mast cells, granulocytes, NK cells, platelets, and endothelial cells
proteins: complement system, clotting factors, kinins, and cytokines
6
Q
explain the third line of defense
A
initiated when the immune system signals cells of adaptive immunity
cells: T and B lymphocytes, macrophages, and dendritic cells
proteins: antibodies, complement, and cytokines
delayed first response but immediate second response
specific response with memory by B and T lymphocytes and antibodies
7
Q
what is the cell-mediated immunity (cellular) portion of the adaptive immune system
A
defense against intracellular microbes, foreign cells from transplanted organs, and cancer cells
brought about by: helpter T lymphocytes (CD4), cytotoxic killer T lymphocytes (CTL or CD8), and regulatory T lymphocytes (Treg)
8
Q
what do the helper T lymphocytes of the adaptive immune system do
A
stimulate B lymphocytes to destroy microbes
and make antibodies (immunoglobulins)
9
Q
what do cytotoxic killer T lymphocytes do in the adaptive immune system
A
kill infected cells
10
Q
what do regulatory T lymphocytes in the adaptive immune system do
A
limit immune responses
prevent reactions again self antigens
11
Q
what is the antibody-mediated immunity (humoral) portion of the adaptive immune systen
A
carried out by B cells from bone marrow and their antibody proteins
protect against extracellular microbes and their toxins
12
Q
explain how T cells are made and differentiated
A
lymphoid stem cells divide in the bone marrow
immature T cells leave the bone marrow then go to the thymus to mature and make clones
mature naive cells go to lymphoid organs
13
Q
what does the thymus screen for
A
immunocompetent cells: destroys clones that cannot recognize antigens
self tolerance: destroys clones that recognize your own cells as foreign
14
Q
what is immunocompetent
A
ability to mount a normal response to a foreign antigen
15
Q
how does activating a tell cell work
A
each T cell has a T cell receptor complex embedded in its plasma membrane thats made of signal 1 and 2
signal 1 binds to MHC complexes on antigen presenting cell
singal 2 binds to an additional signal on antigen presenting cell
T cell is now activated once both signals are bound
16
Q
what are MHC complexes made of
A
MHC 1 or 2 molecule with a peptide antigen
17
Q
what is a major histocompatibility complex molecule
A
cell surface glycoprotein
found on all nucleated cells except erythrocytes
serve as docking sites for specific components of antigens
class 1 and 2 MHC molecules
18
Q
what are class 1 MHC molecules
A
found on surface of plasma membrane on nearly all nucleated cells
present endogenous antigens such as bacteria, cancer cells, or viruses
19
Q
which MHC class do cytotoxic T cells interact with
A
class 1 MHC molecules
kills diseased cell
20
Q
what are class 2 MHC molecules
A
found only on surfaces of antigen-presenting cells (APC)
present exogenous antigens
21
Q
which cells are antigen presenting cells
A
macrophages, dendritic, and B cells
22
Q
which class of MHC molecule do helper T cells interact with and what do they do
A
class 2 MHC molecules
stimulate other parts of the innate and adaptive defenses to combat threat
23
Q
what are the three things that a naive CD4 T cell can differentiate into
A
Th1, Th2, and Th17
24
Q
what does a Th1 T cell do
A
activate macrophages
25
what does a Th2 T cell do
stimulate IgE production
activate mast cells and eosinophils
26
what do Th17 T cells do
recruit neutrophils and monocytes
27
how are B cells formed
lymphoid stem cells divide in the bone marrow
B cells mature in the bone marrow
mature naive B cells exit bone marrow and live in lymphoid organs
B cells not exposed to their specific antigen within a few days or weeks die
28
why do only 10% of B cells finish their maturation process
prevents development of autoimmunity (body attacking itself)
29
explain how naive B cells are activated
antigen binds to receptor on B cell and becomes activated
now sensitized B cell processes antigen and presents it on its class 2 MHC molecules
B cell binds to a Th cell which secretes cytokines to activate B cell
B cell divides repeatedly into cells that can differentiate into plasma or memory B cells
plasma cells secrete antibodies
30
what is a clone
a group of B cells that binds to a specific antigen
31
what are proteins secreted by B cells called
antibodies
32
explain the structure of an antibody
Y-shaped molecule formed from four peptide chains (2 heavy (H) and two light (L) chains)
each heavy and light chain has a constant (C) and variable (V) region
antigen-binding site on V region
33
what does the constant (C) region on an antibody do
responsible for many of antibody's affects
34
what does the variable (V) region of an antibody do
responsible for antigen recognition and binding
35
what are the three shape types of antibodies
monomer (1 antibody)
dimer (2 antibodies)
pentamer (5 antibodies)
36
what are the 5 classes of antibodies
IgG, IgA, IgM, IgE, and IgD
37
which type of shape of antibody is IgM
pentamer
38
which type of shape of antibody is IgA
dimer
39
which classes of antibodies are monomers
IgG, IgE, and IgD
40
what is the agglutination/precipitation action of antibodies
antibodies clump together to enhance phagocytosis
41
what is the opsonization action of antibodies
IgG coats antigens and binds phagocytes, enhancing phagocytosis
42
what is the neutralization action of antibodies
antibodies bind pathogenic components of toxins and block toxin effects
43
what is the complement activation action of antibodies
antibodies activate complement proteins, leading to cell lysis
44
what is the stimulation of inflammation action of antibodies
IgE binds mast cells and basophils and triggers release of inflammatory mediators
45
what do B cell receptor (BCR) complexes do
found on the surface of every naive B cell
must first bind to antigen then another signal
46
what is the first signal of B cell receptor complex
antigen binds to transmembrane protein and IgD or IgM
47
what is the second signal of the B cell receptor complex
complement protein and antigen bind to transmembrane protein
48
what do B lymphocytes do
neutralize microbes, phagocytosis, and complement activation
49
what do regulatory T lymphocytes do
limit immune response to prevent the reactions against self antigens
50
what is hypersensitivity
excessive or harmful reaction to an antigen that results in disease or damage to the host
results from failure of normal regulation
51
what are the four types of hypersensitivity
type 1: immediate (IgE-mediated)
type 2: antibody-mediated (tissue-specific)
type 3: immune complex-mediated
type 4: cell-mediated (delayed-type)
52
what is type 2 hypersensitivity
IgG and IgM antibody production
antigen binds and causes lysis of cell and leukocyte recruitment
ex. autoimmune anemia
53
what is type 3 hypersensitivity
antigen-antibody complexes are deposited
recruitment of leukocytes
release of enzymes
ex. lupus
54
what is type 4 hypersensitivity
activated T lymphocytes cause macrophage activation
ex. MS and tuberculosis
55
what is immediate type 1 hypersensitivity
rapid reaction to a previously exposed antigen binding to IgE on mast cell surface
immediate reaction: vasodilation and smooth muscle spasm
late phase: eosinophils, neutrophils, basophils, monocytes, and T cell - tissue damage
ex. allergies
56
what are three examples of preformed mediators in granules
vasoactive amines (histamine)
enzymes (proteases and hydrolases)
proteoglycans (heparin)
57
what are three examples of lipid mediators
leukotrienes
prostaglandin D2
platelet-activating factor (PAF)
58
what are three examples of cytokines
TNF, IL-1, and chemokines
59
what are 5 examples of a local allergic reaction
bronchial asthma
allergic rhinitis (nasal congestion)
urticaria (hives)
food allergies
atopic dermatisis (eczema)
60
what is an example of a systemic reaction
anaphylaxis from drugs, bee stings, or food
61
what are the common allergens and response of systemic anaphylaxis
allergens: drugs, serum, venoms, peanuts
response: edema, increased vascular permability, tracheal occlusion, circulatory collapse, death
62
what are the common allergens and response of acute urticaria
allergens: insect bites and allergy testing
response: local increase in blood flow and vascular permability
63
what are the common allergens and response of allergic rhinitis
allergens: pollen and dust-mite feces
response: edema and irritation of nasal mucosa
64
what are the common allergens and response of asthma
allergers: cat dander, pollen, dust-mite feces
response: bronchial constriction, increased mucous production, airway inflammation
65
what are the common allergens and response of food allergies
allergens: tree nuts, peanuts, shellfish, milk, eggs, and fish
response: vomiting, diarrhea, pruritis (itching), urticaria, and anaphylaxis
66
explain anaphylactic shock
hypersensitivity reaction involving 2 or more body systems
systemic release of histamine that cause spasm of respiratory tract, vasodilation causing vascular shock, and increased capillary permeability causing edema
causes: heterologous proteins, hormones, enzymes, polysaccharides, drugs, food allergens, and insect toxins
67
what are 6 treatments for type 1 hypersensitivity reactions
epinephrine (anaphylaxis shock)
bronchodilators (beta agonists and albuterol)
steroids (methylprednisolone)
antihistamines (H1 antagonists
avoidance
immunotherapy (desensitization)
68
what is antibody-mediated (type 2) hypersensitivity
IgG or IgM antibodies react with antigens and cause disease
three types: opsonization and phagocytosis, inflammation, and cellular dysfunction
69
explain how opsonization and phagocytosis of antibody-mediated (type 2) injury works
opsonized cells binds to a phagocyte
phagocyte engulfs cell
ex. transfusion reactions, hemolytic disease of fetus, AIHA, and certain drug reactions
70
explain how complement and Fc receptor-mediated inflammation of antibody-mediated (type 2) injury works
deposited antibodies cause activation of leukocytes with Fc receptors
activation of leukocytes causes release of its substances like lysosomal enzymes which causes inflammation
ex. Goodpasture syndrome
71
explain how antibody-mediated (type 2) cellular disfunction works
antibodies impair normal function of cell surface receptors but don't cause cell damage
ex. Myasthenia gravis and Grave's disease
72
what is hemolytic disease of the fetus and newborn (erythroblastosis fetalis)
when a Rh-negative mother has a Rh-positive fetus
during childbirth, Rh-positive fetus cells can enter material bloodstream, making the female form antibodies again Rh-positive cells (sensitization)
if she has another Rh-positive baby, these antibodies will attack the fetus's red blood cells
73
what is Goodpasture syndrome
a type of type 2 hypersensitivity
complement and Fc receptor mediated inflammation
autoantibody attacks noncollagenous protein in basement membranes of kidney glomeruli and lung alveoli
presents with: glomerulonephritis and necrotizing hemorrhagic interstitial pneumonitis
74
what is myasthenia gravis
type of type 2 hypersensitivity
antibodies block acetylcholine receptors at neuromuscular synapse which prevents muscle activation through antibody mediated cellular dysfunction
presents with: muscle weakness, especially ocular muscles, thymus hyperplasia, and thymoma
treated with: immunosuppressive drugs and plasmapheresis
75
what is Graves' Disease (hyperthyroidism)
type of type 2 hypersensitivity
antibodies stimulate TSH receptors leading to over expression and production of thyroxine (T4) and triiodothyronine (T3) through antibody-mediated cellular dysfunction
most common in women 20-40 yrs
presents with: goiter, ophthalmopathy, and weight loss
76
what is autoimmune hemolytic anemia (AIHA)
a type of type 2 hypersensitivity
antibodies attack red cell membrane proteins by opsonization and phagocytosis of red blood cells
presents with: hemolysis and anemia
77
what is immune complex-mediated (type 3) hypersensitivity
antigen-antibody complexes (IgG) or immune complexes not cleared by phagocytes produce tissue damage mainly by eliciting inflammation at sites of deposition
typically deposit in capillary beds in kidneys (glomerulonephritis), small blood vessels (vasculitis), and synovial membranes of joints (arthritis)
deposition triggers activation of compliment system, inflammation, then tissue damage
antigens can be exogenous or endogenous
78
what type of hypersensitivity reaction is post streptococcal glomerulonephritis and what does it present with
local type 3 (immune complex-mediated)
presents with nephritis
78
what type of hypersensitivity reaction is systemic lupus and what does it present with
type 3 (immune complex-mediated)
presents with: nephritis, skin lesions, and arthritis
79
what type of hypersensitivity reaction is polyarteritis nodosa and what does it present with
systemic type 3 (immune complex-mediated)
presents with systemic vasculitis
80
what type of hypersensitivity reaction is reactive arthritis and what does it present with
systemic type 3 (immune complex-mediated)
presents with acute arthritis
81
what type of hypersensitivity reaction is serum sickness and what does it present with
systemic type 3 (immune complex-mediated)
presents with arthritis, vasculitis, and nephritis
82
what type of hypersensitivity reaction is Arthus reaction (experimental) and what does it present with
local type 3 (immune complex-mediated)
presents with cutaneous vasculitis
83
what is serum sickness
a type of systemic immune complex disease (type 3)
reaction due to foreign proteins
serum is injected and immune complex forms
once formed, it deposits in vessels, kidneys, and synovial joints leading to inflammation, fever, joint pain (arthralgia), lymph node enlargement, proteinuria, and urticaria
reaction occurs one week after injection
84
what is Arthus Reaction
a type of local immune complex disease (type 3)
injected antigens and preformed antibodies react and lead to fibrinoid necrosis of vessel
leads to a localized area of skin tissue necrosis
85
what is cell mediated (type 4) hypersensitivity
aka delayed-type hypersensitivity (DTH)
inflammation resulting from cytokines produced by antigen activated CD4+ helper T cells
two types: delayed hypersensitivity and T-cell mediated cytotoxicity
86
what is the delayed-type (type 4) hypersensitivity
antigen is administered to someone who has already encountered antigen (immune)
cutaneous reactions takes 1-2 days
helper T cells recognize antigens and bind to MHC molecules as foreign
cells are destroyed by macrophages and neutrophils
ex. TB reaction, contact dermatitis, IBD
87
what is the T-cell mediated cytotoxicity (type 4) hypersensitivity
antigen is presented by antigen presenting cells
cytotoxic T cell kills the APC and therefore antigen by releasing mediators which induce apoptosis
cytokines are produced as a result which causes an inflammatory reaction
ex. type 1 diabetes and viral hepatitis
88
what is contact dermatitis
delayed-type hypersensitivity reaction
allergen such as poison ivy, metals, or other chemicals form complexes with skin proteins
APC displays allergen which activates helper T cells
macrophages and neutrophils destroy cells which causes inflammation and a itchy rash
reaction only happens on any contacts after the first
89
what is type 1 diabetes mellitus
a type of type 4 hypersensitivity
destruction of pancreatic beta cells by cytotoxic T cells
leads to insufficient insulin production
usually develops before 15 yrs
treated with insulin injections
90
autoimmune diseases affect what percentage of the U.S. population
5-10%
91
what is an autoimmune disease
immune reaction against self antigens caused by adaptive immunity
immune system recognizes self antigens as foreign and attacks them
92
what are the two main types of autoimmune disorders
organ specific vs systemic
93
what is central tolerance
immature B and T lymphocyte clones recognize self antigens and either kill them or render them harmless
94
what is peripheral tolerance
silencing of potentially auto reactive T and B cells in peripheral tissues
95
what are the two factors that lead to failure of self-tolerance and development of autoimmunity
inheritance of susceptibility genes which leads to a failure of self-tolerance
environmental triggers like infections promote activation of self-reactive lymphocytes
96
what is molecular mimicry
a mechanism of autoimmune reactions
microbes express antigens that share amino acid sequences with self antigens
immune response against these microbes can activate self-reactive lymphocytes
97
explain what happens when an infection upregulates the expression of costimulators on APCs
a mechanism of autoimmune reactions
APC presents self antigen which activates APC
activated APC expresses costimulatory molecules which leads to activation of self-reactive T cells
98
what is exposure of sequestered antigens
a mechanism of autoimmune reactions
sustentacular cells (nurse cells or Sertoli cells) surround spermatogenic cells to provide support
form blood-testis barrier which prevents immune system cells in bloodstream from detecting newly formed antigens on sperm cells
99
what is systemic lupus erythematous (SLE)
multi systemic disease of autoimmune origin, typically due to type 3 hypersensitivity
causes injury to skin, joints, kidney, and serosal membrane
produces antinuclear antibodies (ANA)
diagnosed by looking for antibodies agains DNA and Smith antigen
presents with: arthritis, molar and discoid rash, vasculitis, renal disorders, photosensitivity, etc.
100
what is Sjogren Syndrome
chronic autoimmune disease causes destruction of the lacrimal and parotid glands
least to keratoconjunctivitis (dry eyes) and xerostomia (dry mouth)
two most important antinuclear antibodies are SS-A (Ro) and SS-B (La)
101
what is systemic sclerosis (scleroderma)
chronic inflammation resulting from autoimmunity
leads to widespread damage of small blood vessels and progressive interstitial and perivascular fibrosis in skin and multiple organs
usually leads to death from renal failure, cardiac failure, pulmonary in sufficiency, or intestinal malabsorption
presents with: skin fibrosis, Raynauds, dysphagia, trouble breathing, proteinuria, etc.
102
what are the 5 main treatments of autoimmune diseases
1.) NSAIDS
2.) immunosuppressive drugs
3.) Thymectomy
4.) plasmapheresis
5.) surgery
103
what are the three immunosuppressive drugs used to treat autoimmune diseases
corticosteroids, disease modifying anti-rheumatic drugs (DMARD), and cyclosporin A
104
what are corticosteroids
drugs used to treat autoimmune disorders by inducing a transient lymphoctopenia
ex. methylprednisolone, prednisone, and cyclophosphamide
105
what are disease modifying anti-rheumatic drugs (DMARD)
drugs used to treat autoimmune disorders by interfering with pathways of inflammatory cascade
ex. rituximab and methotrexate
used mainly to treat RA and SLE
106
what is Cyclosporin A
drug used to treat autoimmune disorders by inhibiting the synthesis of interleukins like IL-2
107
how does a thymectomy treat autoimmune disorders
decreases T-cell activation
108
how does plasmapheresis help to treat autoimmune disorders
helps filter blood
109
what is an example of how surgery can help to treat an autoimmune disorder
joint replacement to combat arthritis
110
what is a host
someone who is receiving a transplant
111
what is a graft
the donor tissue/organ
112
what is a graft rejection
immunological response directed against the donor tissue
113
what is an isograft
donation from an identical twin
no response from cytotoxic T cells because antigens bound to class 1 MHC molecules are no recognized as foreign
ex. bone marrow from one twin is transplanted to another with leukemia
114
what is an autograft
donation from self
no response from cytotoxic T cells because antigens bound to class 1 MHC molecules are not recognized as foreign
ex. skin graft from one part of the body going to another
115
what is an allograft
donation from same species
can lead to a rejection reaction
ex. kidney transplant from a relative or closely matched donor
116
what is a xenograft
donation from a different species
can lead to a rejection reaction
ex. heart valves from pig or cow
117
explain how allografts are rejected
T cells recognize donor HLA antigens (alloantigens) from graft
lymphocytes and antibodies are produced against these antigens and destroy tissue grafts
direct pathway: graft APC presents alloantigen to T cell directly
indirect pathway: alloantigens picked up and presented by host APC
118
what is a hyperacute rejection
rejection is within minutes to hours after transplant
caused by antibodies specific for antigens on graft endothelial cells
direct pathway more involved
119
what is an acute rejection
rejection within days or weeks after transplant
usually T-cell mediated, less often it's B-cell/complement mediated
T-cells and antibodies are activated by alloantigens
acute cellular rejection: T-cells destroy graft cells or release cytokines
acute antibody-mediated rejection: antibodies bind to vascular endothelium and activate compliment
120
what is a chronic rejection
rejection occurs over months or years leading to loss of graft function
fibrosis leads to narrowing of graft blood vessels
mediated by T cells and antibodies
indirect pathway is more involved
121
what is graft versus host rejection (GvH)
immunologically competent cells are transplanted in an immunologically compromised host
transplanted cells recognize alloantigens as host
seen in bone marrow transplants
122
what is a primary (congenital) immunodeficiency
genetically determined, usually result of a single gene defect
can have recurrent infections later in life more rare than secondary
present with: sinusitis, bronchitis, pneumonia, ear infections, and diarrhea
123
what is a secondary (acquired) immunodeficiency
arise as a complication of other diseases
more common than primary
124
what is the main hallmark of an immunodeficiency disease
recurrent infections with opportunistic organisms
125
viral, fungal, yeast, and atypical microorganism infections lead to what deficiency
T cell deficiencies
126
bacterial infections lead to what two types of deficiencies
antibody and complement deficiencies
127
microorganisms requiring opsonization or catalase positive lead to what type of deficiency
phagocyte deficiencies
128
what are the 5 groups of primary immune deficiencies
B lymphocyte
T lymphocyte
combined B and T lymphocyte
complement
phagocyte
129
what are some of the most common symptoms of primary immune deficiencies
sinusitis
bronchitis
pneumonia
ear infections
diarrhea
130
what is severe combined immunodeficiency (SCID)
defect in humoral and cell-mediated immune responses
less T cells, more B cells, and less serum immunoglobulins
131
what is adenosine deaminase deficiency (ADA)
a recessive type of severe combined immunodeficiency (SCID)
deficiency of adenosine leads to a buildup of toxic metabolites which causes damage to immature lymphocytes
treated with: hematopoietic stem cell transplantation, enzyme administration, or gene therapy
132
what are primary B-cell immune deficiencies
B-cell deficiencies
ex. X-linked agammaglobulinemia and isolated IgA deficiency
133
what is X-linked agammaglobulinemia (Bruton agammaglobulinemia)
a type of primary B-cell immune deficiency
mutated Bruton tyrosine kinase (a intracellular signaling enzyme) prevents maturation of B-cells and plasma cells
treated with: immunoglobulin replacement (intravenous immunoglobulin)
134
what is isolated IgA deficiency
a type of primary B-cell immunodeficiency
defect at terminal differentiation of IgA which leads to low serum and secretory IgA
most are asymptomatic but can lead to recurrent infections and diarrhea
increases frequency of autoimmune and allergies
135
what is DiGeorge Syndrome
a type of primary T-cell immunodeficiency
thymus, parathyroids, and thyroid C cells don't develop properly
leads to tetany (because of parathyroid glands), heart defects, facial anomalies, and poor infectious defense
treated with: thymus transplantation
136
what is X-linked hyper-IgM syndrome
defects in helper T-cell-dependent B-cell and macrophage activation caused by mutation in CD40L gene
causes elevated levels of IgM, absence of IgG, IgE, IgA, and poor defense against infections
137
what is chronic granulomatous disease (CGD)
X-linked phagocyte deficiency
defect in genes encoding oxidase enzyme which leads to defective production of ROS (bacteria killing)
macrophage walls off microbes leading to a granuloma
causes susceptibility to recurrent bacterial infections
138
what is Chediak-Higashi Syndrome
a recessive phagocytic deficiency
defect in CHS1(LYST) gene leads to defective phagosome and lysosome function and therefore susceptibility to infections and giant granular aggregates
presents with: defective melanocytes (albinism), nervous system, and platelet function
139
what is C3 deficiency
recessive complement cascade activation deficiency
leads to more infection by bacteria
140
what is C9 deficiency
recessive complement deficiency
membrane attack complex (MAC) can no longer assemble
leads to an increased susceptibility in Neisseria specie bacterias
141
what is Wiskott-Aldrich syndrome
X-linked mutation in WASP gene which leads to T-cell and B-cell defect
T-cell defect leads to progressive loss in peripheral blood and lymph nodes
B-cell defect leads to low IgM
often development of thrombocytopenia, eczema, infections, and B-cell lymphoma
treated with: hemopoietic stem cell transplantations
142
what are some conditions associated with secondary immunodeficiencies
metabolic diseases (diabetes)
malnutrition (vitamin or zinc deficiencies)
malignancies (leukemia)
medial treatments (chemo and radiation)
chronic infections (AIDS)
143
what is acquired immunodeficiency syndrome (AIDS)
disease caused by the untreated RNA retrovirus human immunodeficiency virus (HIV)
depletes the body's CD4+ helper T cells
transmitted through sexual contact, blood to blood, and perinatal
144
explain the mechanisms of HIV infection
gp120 protein binds to receptor on helper T-cell
now new recognition site on gp120 for coreceptors CCR5 and CXCR4
gp120 binds to CCR5 and CXCR4
binding causes fusion of viral and host cell membranes
virus enters cell to hijack replication machinery
145
explain the acute phase of HIV
2-4 weeks
symptoms: headaches, fever, and flu-like
lots of virus in blood
146
explain the chronic phase of HIV
months to years
no symptoms really
lots of antibodies in blood
helper T-cell destruction in blood
147
explain the progression of HIV to AIDS
extreme decline of helper T-cells
lots of infections like pneumocystis jiroveci
increased opportunity for B-cell lymphoma and Kaposi sarcoma
eventually fatal
148
what is the treatment for AIDS
antiretroviral therapy: drugs that stop HIV from entering cells or replicating once inside the cell
expensive and bad side effects
only slows progression
149
what is an autoantibody
an antibody made by the body that will attack the body's own proteins
150
what is a neoantigen
new epitopes that are not normally expressed normally
created when there is an infection, tissue is injured, self antigens are modified
can activate T cells
151
what is an antinuclear antibody
antibody elevated in autoimmune disorders
