3.1.11 Immune Failures Flashcards
What is evasion of immune response?
- Caused by antigenic variation and stereotypes
- Same microorganism can express different antigens on its surface
-Antibody in first immune response is useless when it interacts w/ different antigen
___ is important in influenza viral infections
Genetic recombination
Is there genetic recombination in covid?
No
Antigenic shift can lead to ___. Why?
Pandemic
Results in new virus that humans don’t have antibodies for and the entire population is vulnerable
Describe latency
- Once you’re infected (w/ certain illnesses) you have it for your whole life
- Certain viruses become latent and hidden from immune response
- When activated, they cause recurrent infection
Herpes virus is an example of
Latency
Superantigens are produced by ___ bacteria. They stimulate a ___ response. What do they bind to and what do they connect?
Gram +
Ineffective and nonspecific response
Binds to MHC and connect MHC to T cell receptor
Superantigens have a big response of
IL-2
Gamma IF
TNF alpha
Can primary/ secondary immunodeficiency diseases be genetic or developmental?
Primary
NOT secondary
When does primary and secondary immunodeficiency diseases occur?
Primary at birth
Secondary after birth
Cause and treatment of Bruton’s agammaglobulinemia. What phase of B cycle is it stuck in? What’s a major problem with this disease?
Loss of tyrosine kinase results in lack of antibodies ( B cell defect)
IV-IG monthly
early B cell phase, WONT go to immature B cell phase
recurrent urinary tract infections
Cause of X-linked hyper-IgM syndrome
Lack of receptor for CD40 ligand or CD154 which is expressed by CD4+ T cells
What antibody is produced in X-linked hyper-IgM syndrome? Will macrophages be activated? why/why not?
IgM
No, b/c CD4 normally interacts w/ macrophage and releases gamma IF to activate macrophage to destroy, but since there’s no CD40 ligand, CD4 can’t be activated to interact
Symptom: patients become neutropenic and can develop sores/blisters in mouth
is for what syndrome?
X-linked hyper-IgM syndrome
What is the most common primary immunodeficiency? Describe it. What antibody is found in saliva?
Selective IgA deficiency
IgA is foreign
IgM found in saliva
Digeorge’s syndrome is also called
thymic hypoplasia
Describe Digeorge’s syndrome
What’s an example?
Lack of thymus (T cell defect)
Patients have problems w/ viral infections, fungal infections, intracellular bacterial infections (ex: tuberculosis), parasitic infections…
nude mouse (hairless mouse)
Result of Digeorge’s syndrome
antibody levels are lower than normal b/c lack of CD4+ TfH+ T cells
___ disease lacks cell mediated immunity and humoral immunity
What’s an example?
severe combined immunodeficiency disease
Scid mice
XSCID, RAG deficiency, ADA deficiency are examples of. what are each of their gene defects?
severe combined immunodeficiency disease
XSCID = IL-2 receptor gamma chain
RAG deficiency = RAG1 & RAG2
ADA deficiency = ADA
Chronic granulomatous disease is a defect in ___. What can’t they produce? What does this affect?
patients phagocytic cells
O2 radicals and hydrogen peroxide
affects neutrophils and macrophages
Leukocyte adhesion deficiency has 2 types. What are they?
Type I: lack of a specific integrin on PMNs (LFA-1)
- most common
Type II: lack of selectin receptor on PMNs (neutrophil)
What is the common theme in leukocyte adhesion deficiency?
Patients can develop widespread pyogenic bacterial infections, diapedesis won’t occur (neutrophils can’t respond and kill microorganism)
IL-8 is a ___ which is also a ___
Chemokine
Cytokine
Within complement deficiencies, there is a lack of what 4 things?
Early C components (C1, 2, 4)
C3
membrane attack complexes (C5-9)
C1-esterase inhibitor
In complement deficiencies, a lack of early C components (C1, 2, 4) is associated w/
immune-complex diseases, often autoimmune disease
In complement deficiencies, a lack of C3 leads to
pyogenic bacterial infections
- deficiency in susceptibility to capsulated bacteria
In complement deficiencies, a lack of membrane attack complex (C5-9) leads to
infection w/ neisseria SPP
In complement deficiencies, a lack of C1-esterase inhibitor leads to
hereditary angioneurotic edema (HANE)
complement deficiencies can affect ___ components/leads to defects in taking up of ___
early complement
immune complexes
3 causes of secondary response
Malnutrition
Malignancy
Infections
AIDS is caused by ___ , which infects ___
HIV
HIV infects CD4+ T cells all CD4+ subsets
How can primary immune diseases be cured from patient? What are the steps?
Through BM transplant
Steps:
- Irradiation and chemotherapy (destroys bone marrow)
- Bone marrow infusion (Take donor blood w/ activated stem cells)
- Healthy patient
Immunosuppressive therapy is used in treating patients w/
autoimmune diseases & in transplant setting
Opportunistic infections are caused by
microbes held in check by immune system but in the immunocompromised host the infection may be life threatening
Infections may be caused by
parasites, bacteria, fungi and viruses
