3.1 Immune Failures Flashcards
what is an example of evasion by antigenic variation?
- Person is infected by different stereotypes of a bacteria (ex: S. pneumoniae)
- antibodies clear infection, but they are specific to that stereotype 3. they can NOT protect against another stereotype (will need a new antibody)
________ is when an antigenic shift occurs when RNA segments are exchanged between viral strains in a secondary host
Genetic Recombination
which virus uses genetic recombination?
Flu (it is made of 8 separate RNA segments held together by protein linkage → when inside cell, linkages come apart and recombination occurs)
_______ is a complete change in antigenicity
Antigenic shift
- pig infected with human and avian strands of flu virus
- recombination of human and avian RNA produces new virus
- no humans will have antibodies for this
This is an example of what?
antigenic shift
SARS-Co-2 is a single strand of RNA that can have _________ but NOT ______
point mutations
recombination
what can lead to a pandemic?
antigenic shift
_______ is when certain viruses can become latent/ hidden from immune response, but when activated they can cause a recurrent infection
latent
herpes is an example of ______
latency
Superantigens produced by gram _______ bacteria and have a _____ response
positive, nonspecific
what are the steps of a superantigen reaction?
- Superatigen binds to MHC →
- binds to certain types of Beta chain on TCR
- APC already activated so B7/CD28 interact
- massive response of IL-2, gamma IF, TNF-a
superantigen reactions have which kinds of cytokines?
IL2, gamma IF, TNF-a
_____ immunodeficiency diseases are seen at birth (genetic or developmental, dominant, recessive, or x-linked)
Primary (congenital)
what are examples of primary diseases?
- Bruton’s/X-linked Agammaglobulinemia:
- X-linked Hyper-IgM syndrome
- Selective IgA deficiency:
- DiGeorge’s syndrome:
- SCID:
- Severe combined immunodeficiency disease
- Chronic granulomatous disease (CGD)
- Leukocyte adhesion deficiency (LAD)
- Complement deficiencies
____________ is a B cell defect
Bruton’s/X-linked Agammaglobulinemia
can you handle viral infections if you have Bruton/s agammaglobulinemia?
yes, you still have CMI
what is the cause of Brutons disease?
loss of Bruton’s Tyrosine kinase (results in lack of B cell development, B cell stopped when Pre-B cell tries to leave BM)
what is treatment for brutons?
IV-IG monthly
X-linked Hyper-IgM syndrome is a disease in which people have a Lack of receptor for __________
CD40L or CD154 (expressed by CD4+ T-cells)
if you have X-linked Hyper-IgM syndrome, there is no response to ________ antigens causing only ____ to be produced
T dependent
IgM
what is the most common IDD?
selective IgA deficiency
in someone with Selective IgA deficiency you would Expect to find _____ in their saliva/secretions
IgM
_______ is a lack of thymus, which is a T-cell defect
DiGeorge’s syndrome
In people with Digeorges syndome, if there are no TH2+ cells, what is the result of this?
can’t respond to T-dependent antigen, only can make B1 responses
are antibody levels lower or higher in people with DiGeorges syndome?
Lower
_______ is an IDD that results in a lac of cell mediated immunity and humoral immunity (T-cell dependent)
SCID
what are the different types of SCIDs?
- XSCID: lack of IL2 receptor and Gamma chain
- RAG deficiency: no T or B rearrangement or recombo
- ADA def: build up metabolic products that are toxic to T,B, NK cells
RAG doesn’t affect _______ cells bc they dont go through recombination
NK
___________ happens when there is a Defect in patients phagocytic cells
Chronic granulomatous disease (CGD)
what happens in the cells in CGD? which cells does this effect?
- can phagocytize a microbe but are unable to destroy them
-Can’t form O2 radicals and hydrogen peroxide
-Affects neutrophils and macrophages
_________ is a primary immunodeficiency that causes individuals to be abnormally susceptible to developing frequent soft-tissue infections, gum inflammation, and tooth loss.
Leukocyte adhesion deficiency (LAD)
compare Type 1 vs Type 2 LAD
- Type I: lack of a specific integrin on PMNs (LFA-1) –> Leukocyte cant interact with ICAM1 –> no diapedesis –> neutrophil cant enter tissue to kill (can roll but not diapedesis)
-Type II: lack of selectin receptor on PMNs (cant roll or do diapedesis)
what are the different types of complement deficiencies?
-Lack of early C components (C1, 2, 4):
-Lack of C3:
-Lack of membrane attack complex:
-Lack/Non-fxn of C1-esterase inhibitor:
what is the result of lack of early C components?
this deficiency leads to immune-complex diseases, often autoimmune disease
what is the result of lack of C3?
leads to pyogenic bacterial infections and higher susceptibility to capsulated bacteria
what is the result of having a lack of MAC?
infection w/ neisseria SPP
what is the result of lack/non-function of C1-esterase inhibitor?
leads to deficiency in hereditary angioneurotic edema (HANE)
_________ Prevents the non-specific activation of C1 and can cause random swelling
hereditary angioedema
Some primary immune diseases have been cured from patient through ____________
bone marrow transplant
Secondary (acquired) IDDs occur ________
after birth
what are some causes of secondary IDDs?
- Malnutrition in developing countries
- Malignancy: Problems w/ infections and immunosuppression caused by treatment/disease
- Infections: Microbe causes immunodeficiency (HIV & measles virus)
___________________ is an example of a secondary IDD that is caused by HIV
Acquired immunodeficiency syndrome (AIDS)
what does HIV infect and have an effect on?
-HIV infects CD4+ T cells all CD4+ subsets, monocytes, macrophages and DC
-Large effect on CD4+ T cells and cell mediated immune responses
___________ is used in treating patients w/ autoimmune diseases & in transplant setting
Immunosuppressive therapy
_______ occur when microbes held in check by immune system cause infection in an immunocompromised host and may be life threatening
opportunistic infections
