Week 4 Flashcards
Enterococcus faecalis
Gram positive Cocci
Normal flora in gut
Highly resistant, including vancomycin
Gram Positive Cocci
Strep. pyogenes (group A)
Strep. pneumoniae
Strep. viridans (normal flora)
Staph. aureus Staph epidermidis (normal flora)
Group B beta-hemolytic strep: Strep. agalactiae
Enterococcus faecalis
Central tolerance
Deletion of self reactive clones of lymphocytes - negative selection
Peripheral tolerance
Lymphocyte interacts with antigen –> no subsequent response
Clonal anergy
T cell recognize self antigen but no Co-stimulatory signal
Functional unresponsiveness
Regulatory T cells
FoxP3, CD25 - markers for regulatory T-cells
Inhibit T cell activation
Inhibit T cell effector functions
Activation induced cell death
Apoptosis induced by apoptotic proteins
Death ligands
Receptor editing (B-cell)
New light chain rearrangement replacing original VL chain in B cell
Molecular mimicry
Normal foreign antigen response cross reacts with self antigen
(Rheumatic fever)
Celiac disease HLA typing
95% DQ2
DQ8
Used for diagnostic exclusion
Multiple Sclerosis
Autoimmune response against myelin sheath –> demyelination
Animal model: EAE
Transfer disease to healthy animal –> recipient gets disease
Insulin dependent diabetes mellitus
Insulitis in islet cells
Rheumatoid factor
Autoantibodies against Fc portion of IgG
X-linked agammaglobulinemia
Bruton’s
Defect in btk gene, disrupted B cell development
Pro –> pre blocked
Selective IgA deficiency
Deficiency in IgA
Anaphylactoid rxn to blood transfusion
Hyper IgM immunodeficiency
Lack of CD40L (t cell help)
Elevated IgM and low/no class switching to other Ig’s
X-linked
CVID - Common variable immunodeficiency
Immunoglobulin deficiency
B cell and Ig deficiency
Wide variety
Recurrent infection
Lymphoproliferative diseases
Autoimmune cytopenias
DiGeorge syndrome
Thymic aplasia:
Thymus doesn’t form –> low T cell count
Hypocalcemia, congenital heart defects
Gamma chain deficiency
SCID: Common gamma chain that is subunit of cytokine receptors (IL-2, 4, 7, 9, 15)
T cell and NK cell deficiency
B cell intact (but T cell count affects B cell activation)
Adenosine deaminase deficiency
SCID: Severe absence of T cell function
Accumulation of toxic product that kills T cells
T, B, and NK deficiency
Bare lymphocyte syndrome (II)
SCID: Lack of MHC class II expression (transcription factor defect)
No CD4+ cells –> B cells affected
Tcell receptor Excision Circles
Circular genome that is lost during T cell gene rearrangement - should have large amount as child while making T cells
Screen for TREC to diagnose immunodeficiencies
PAMPS
Pathogen associated molecular patterns
DAMPS
Danger associated molecular patterns