Block 1 Disease Flashcards
Ginigivitis and internal ulcering
Given as examples of what could happen with a deficiency in innate immunity; other scenarios given = you can have absence of appropriate leukocyte migration (lack of chemokine attractants); you also might be able to get the leukocytes to the site of invasion but cannot effectively kill
Severe Combined Immunodeficiency (SCID)
David the Bubble Boy, lived in a sterile chamber for 12 years; could not make B and T cells; X-linked recessive; Bone marrow transplant is treatment; common gamma chain deficiency; Gamma is in the signaling subunit of the receptors for several cytokines, including IL-2, 4, 7, 9, 15 and 21. When the gamma chain is not functional, immature lymphocytes cannot proliferate in response to IL-7, which is the major growth factor for these cells. Contrast this with Autosomal SCID (ADA deficiency), page 227.
Gout
Deficiency in innate immunity; PRRs recognize endogenous (host-derived) molecule uric acid, which leads to inflammation, inflammasome activation
Lupus
Deficiency at the level of adaptive immunity; see lecture 14’s SLE explanation
MS
Deficiency in adaptive immunity- adaptive immune response against self antigens
Deficiency in epithelial sloughing
Some microbes have increased capacity for colonization, adherence. If you don’t have sloughing off mechanisms (like in vaginal epithelium), you are more susceptible to certain infections; see Neisseria Gonorrhoeae (lecture 3)
Chronis Bronchiolitis
Smoking leads to torching of epithelial cilia
Cystic Fibrosis
Dehydrated mucous gets trapped, allowing for increased susceptibility of microbes for taking up residence in the lung
Crohn’s Disease
Pathogens in the gut are especially problematic when there is significant damage to the epithelial lining, as seen in Crohn’s Disease (see CC-02 notes below for more on Crohn’s Disease)
Respiratory Syncytial Virus
In the case of RSV, you can give macrophages which can be alternatively activated (differentiation to M2 state)– confers protection against the lung damage which would normally occur in such an infection (BUT, also confers asthmatic-type reaction with alternative activation macrophage pathway, not just wound repair)
Alzheimer’s
When B-amyloid aggregates in the brain, as in Alzheimer’s, can be seen by the immune system as a danger associated molecular pattern, or DAMP, and lead to inflammation
Gram negative sepsis
Dysregulated production of pro-inflammatory cytokines (“cytokine storm”), ROS, lipid metabolites , bystander cell damage produces DAMPs which feed back on the macrophages to produce even more cytokines and dysregulation
NADPH-Oxidase Deficiency; Chronic Granulomatous Disease (CGD)
Cannot convert oxygen to superoxide anion, which leads to recurrent bacterial infection (ROS is a potent microbicidal agent that aids lysosomes when lysosomal destruction is not sufficent); important to know that MPO deficiency, though also leading to lower levels of free radicals, isn’t as severe (MPO is more downstream in the pathway on slide 67); also important to know that deficiencies in any of the enzymes of the COUPLED reactions (i.e. Glutathione reductase) will have phenotype similar to that of NADPH Oxidase deficiency (CGD)
Chediak-Higashi Syndrome
Abnormal fusion of phagosomes with lysosomes. Failure to kill ingested microbes; impaired myeloperoxidase also presented in the context of a decreased ability for CD8 cells to KILL. From the book “AR immunodeficiency disease due to a defect in cytoplasmic granules of various cell types that 1. affects the LYSOSOMES of macrophages and neutrophils and 2. affects the granules of CD8 cells and NK cells. Patients show reduced resistance to infections with pyogenic (pus-causing) bacteria.
Leukocyte Adhesion Deficiency (LAD)
Leukocytes can’t bind to endothelium and thus, they cannot diapedese. Due to AR mutation that results in faulty expression of CD18 (CD11a/CD18 and CD11b/CD18) are present on neutrophils and monocytes and are pivotal to attachment to endothelium for diapedesis into the tissues
Complement System Abnormalities
Example is a C8 deficiency; increased frequency of Neisseria infection, no formation of the MAC (this is always asked about on board exams)
IRAK4 deficiency
Defect in a key enzyme in TLR signaling (the first enzyme that is recruited to MyD88) in recurrent bacterial infections (mostly Gram +) Block the signaling pathway (#1) that leads to NFKB
TLR polymorphisms
Example (TLR4), increased sensitivity to certain infections
Pneumococcus
Resistance to phagocytosis; capsular polysaccharide inhibits phagocytosis; lots of serotypes prevent vaccine development
Staphylococci
Resistance to ROS in phagocytes; production of catalase by staph breaks down reactive oxygen intermediates
Neisseria meningitides
Resistance to complement activation (alternative pathway); Sialic acid expression inhibits C3 and C5 convertases
Streptococcus
Streptococcus is gram positive and its outer surface is peptidoglycan (recognized by TLR2). Resistance to complement activation (alternative pathway); M protein blocks C3 binding to organism and C3b binding to complement receptors; How do you make a streptococcus pneumoniae conjugate vaccine? (Lecture 5, slide 31)
Pseudomonas
Resistance to antimicrobial peptide antibiotics; synthesis of modified LPS that resists action of peptide antibiotics
Neisseria gonorrhoeae
Prevent cell sloughing; increase adhesion molecules on vaginal epithelial cels– decreases sloughing, Neisseria is an encapsulated bacteria (C’ is important for defense, especially MAC, so we must vaccinate C’-suppressed folks)
Paroxysmal Nocturnal Hemoglobinuria
CD59, CD55, and GPI Deficiencies. CD59 (or protectin) inhibits formation of the MAC on autologous or allogenic cells (widely expressed on membranes)
Hereditary Angioneurotic Edema HA(N)E
C1 INH Deficiency
Candida
Yeast, attract factor H to their surface, so complement cannot be activated
Helicobacter
Usually destroyed by the lytic cascade; CD59 (the molecule that inhibits MAC formation) can be incorporated into the bug
Leishmania
Leishmania will actually use iC3b to its advantage. Phagocyte will take up parasite; then Leishmania will inhibit phagosome-lysosome fusion. Uses complement system to its advantage.
Hypersensitivity reaction to allergens
IgE reaction: sets off FC epsilon receptor chain of events (on mast cells and eosinophils) leading to granule release. The same thing occurs (normally) as a reaction to helminths, or worms
Polio
The oral attenuated polio virus functions in neutraliization of the virus by mucosal IgA antibody
Tetanus, diphtheria
The toxoid vaccine: functions by neutralizatoion of toxin by systemic IgG antibody
Hepatitis, A or B
The recombinant viral envelope proteins in vaccine: function to induce neutralization of virus by systemic IgG antibody
Pneumococcal pneumonia, haemophilus
Conjugate vaccines (composed of bacterial capsular polysaccharide and protein) work by promoting opsonization and phagocytosis mediated by IgM and IgG antibodies, directly or secondary to complement activation