Lecture 15 Flashcards
(18 cards)
What causes congenital immunodeficiencies?
- genetic defects that lead to blocks in maturation or functions of different components of immune system
- defects that block maturation of B cells, T cells, or both
Severe combined immunodeficiency (SCID)
-defects in both B and T cells
X-SCID caused by gamma-c mutations
- affect only male children
- mutation in γc chain
Major cytokine involved in NK cell proliferation and maturation
IL-15
mutation of aenosine deaminase (ADA)
accumulation of toxic purine metabolites
-result in more of a block in T cell maturation than B cell
X-linked Agammaglobulinemia
- block in B cell maturation since pre-B cells fail to expand and caused reduced serum Igs
- mutation in bruton tyrosine kinase (BTK)
X-linked hyper-IgM syndrome
- defect in B cell switching
- so main serum Ab is IgM
- mutations in CD40 ligand
Common variable immunodeficiency
- poor Ab response to infection and reduced serum levels
- mutation in receptors for B cell growth
Bare lymphocyte syndrome
-failure to express MHC II
Defects in TCR complex expression/signaling
-mutations in CD3 proteins
Defects in Th1 differentiation
-mutation in receptors for IL-12 or IFN-gamma
Defects in Th17 differentiation
-mutation in genes encoding IL-17
Chronic granulomatous disease
-mutations in genes for enzyme phagocyte oxidase
Leukocyte adhesion deficiency
-mutations in genes encoding integrins
HIV is a retrovirus which infects which T cells?
CD4+ T cells
What is the life cycle of HIV?
- infection of cells
- production of DNA copy of viral RNA
- integration into host genome
- expression of viral genes
- production of viral particles
HIV binds to which chemokine receptors on human cells?
-CXCR4 and CCR5
What are the clinicopathologic manifestations of full-blown AIDS?
-increased susceptibility to infections and some cancers as consequence of immune deficiency
