Lecture 19 Flashcards

(29 cards)

1
Q

What is a primary immunodeficiency?

A
  • inherited disorders with defects in 1+ components of the immune system
  • infections are hallmarks
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2
Q

What are secondary immunodeficiencies?

A
  • non-inherited, acquired
  • caused by environmental facotrs
  • infections are hallmarks
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3
Q

What are combined immunodeficies

A
  • impairments in both B- and T-cell function
  • inherited mutations
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4
Q

What defect causes pyogenic (pus-forming) bacterial infection in primary immunodeficiencies?

A

defect in antibody, complement or phagocyte function

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5
Q

What defect typically causes persistent fungal or viral infection in primary immunodeficiencies?

A

defect in T-cell function

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6
Q

What are Combined Immunodeficiencies limited to the immune system? (give examples, cells affected, immune defect and antibody level)

A
  • Yc and RAG-1/2 deficiency
  • T, B and NK cells
  • deficient T, B and NK cell development
  • low antibody
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7
Q

What are Combined Immunodeficiencies with defects in tissues outside the immune system? (give examples, cells affected, immune defect and antibody level)

A
  • FOXN1 and Job syndrome
  • thymic epithelium, TH17 and TFH cell development affected
  • Deficient/defective T cell, TH17 and TFH cell development
  • decreased antibody / high IgE
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8
Q

What areantibody deficiencies? (give examples, cells affected, immune defect and antibody level)

A
  • Bruton’s X-linked agammaglobulinemia, AID deficiency, Selective IgA deficiency
  • B cells affected
  • defective Ig class-switching and somatic hypermutation / absent mature B cells
  • low antibody, IgG/IgA low + IgM increased, low-absent IgA
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9
Q

What is immune dysregulation? (give examples, cells affected, immune def

A
  • perforin deficiency, IL-10 deficiency
  • CTLs, NK cells and multiple others
  • impaired CTL and NK-cell cytotoxicity and no IL-10
  • normal antibody
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10
Q

What are phagocyte defects? (give examples, cells affected, immune defect and antibody level)

A
  • Elastase deficiency, GATA2 deficiency
  • neutrophiles, monocytes, DCs
  • neutrophil, monocyte, DC deficiency
  • normal antibody
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11
Q

What are innate immunity defects? (give examples, cells affected, immune defect and antibody level)

A
  • IL-12p40 deficiency, IFN-y receptor 1 deficiency
  • DCs, monocytes, macrophages and multiple others
  • IFN-y secretion and signaling
  • normal antibody
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12
Q

What are Autoinflammatory disorders? (give examples, cells affected, immune defect and antibody level)

A
  • Muckle-Wells syndrome
  • neutrophils, monocytes
  • inflammasome hyperactivity
  • normal antibody
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13
Q

What are Complement deficiencies? (give examples, cells affected, immune defect and antibody level)

A
  • C1q deficiency, MASP deficiency
  • apoptotic cells / none
  • deficient activation of classical / lectin complement pathway
  • normal antibody
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14
Q

What are phenocopies of inborn errors of immunity? (give examples, cells affected, immune defect and antibody level)

A
  • APECED deficiency
  • T cells
  • impaired negative selection of T cells
  • normal with autoantibodies
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15
Q

What does adenosine deaminase deficiency disrupt and subsequently cause? what can it be treated with?

A
  • disrupts S-phase of cell cycle
  • lack of circulating T and B cells
  • causes SCID in infancy, can be treated with bone marrow transplantation
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16
Q

What does Omenn syndrome cause?

A
  • partial loss of V(D)J recombinase activity through mutations in RAG1 or RAG2 alleles
  • peripheral T cells are autoreactive
17
Q

How does FOXN1 mutation affect T cells?

A

lack of thymic function, leads to abnormal T-cell development

18
Q

How does DiGeorge syndrome affect T cells?

A
  • thymus is absent
  • abnormal T-cell development and function
19
Q

How does Bare Lymphocyte Syndrome affect T cells?

A
  • MHC class I or II deficiency
  • improper activation of CD8 (MHC class I)
  • mutation in TFs responsible for MHC II expression
20
Q

How does X-linked Agammaglobulinemia affect B cells?

A
  • failure of B cell precursors to mature into B cells and then plasma cells
  • low levels of all isotypes
  • reduced B cell #s
21
Q

What is Hyper IgM syndrome?

A
  • affects Igs
  • only males
  • caused by mutation in CD40 ligand
  • low levels of IgG, IgA and IgE (IgM might be low, normal or elevated)
22
Q

What is chronic granulomatous disorder?

A
  • defects in phagocytes where they cannot kill certain pathogens
  • vulnerability to severe recurrent bacterial and fungal infefctions
23
Q

what is leukocyte adhesion deficiency?

A
  • defects in migration of phagocytes
  • patients are deficient in the expression of 3 integrins containing CD18 (LFA-1, Mac-2, Gp 150/195
24
Q

What is Chediak-Higashi syndrome?

A
  • defects in phagocytes
  • impaired lysis of phagocytosed bacteria
  • abnormal NK cell function
  • defective lysosomal function in macrophages, DCs and neutrophils
25
What are mechanisms of immune evasion?
* antigenic variation - pathogen expresses diff surface antigens w/o changing bacterial genus and species * pathogenic bacteria target complement cascase to subvert immunity
26
What is viral latency?
when viruses incorporate their viral genomes into target cells and undergo a state of latency (dormancy). reactivation of viral genome expression and protein expression eventually.
27
What is the HIV protein that we talked about in lecture and what does it do?
* gp120 * recognizes CD4, CCR5, CXCR4 receptors
28
What is the life cycle of HIV?
* virus particle binds to CD4 and co-receptor on T cell * Viral envelope fuses w cell membrane allowing viral genome to enter cell * reverse transcriptase copies viral RNA genomes into double stranded cDNA * viral cDNA integrated into host DNA * T-cell activation induces low-level transcription of provirus * tat and rev gene translation * tat amplifies transcription of viral RNA * rev increases transport of singly spliced or unspliced viral RNA to cytoplasm * other late proteins are translated and assembled into virus particles which bud from the cell
29
How does HIV work?
* after initial infection, viral genome titre increases dramatically * initial decrease in CD4 T cells until viral latency * during progression, viral titre remains unchanged, but CD4 cells continue to decrease in number * if untreated, CD4 levels decrease to extent that allows onset of infection until patient succumbs