Immunology Review Hy

Interferons secretd upon Virus infection

• Inf Alpha, Beta synthesized in response to virus infection –> Secreted out and bind to Inf receptors in neihhbouring cells –> paracrine/autocrine signalling –> Transcription of antiviral enzymes RNase L (endonuclease that degrades RNA in the cell) and ProteinKinaseR –> PKR —(-)-> elF-2 –> Active only in double stranded RNA –> Thus only infects cells with viral replication and does not hinder uninfected cells

• Induce MHC I –> T, NK cell activity increase

Cladribine, Coformycin: ADA inhibtors

• Hairy cell leukemia

Chronic Lung Transplant Rejection

• Submucosal lymphocytic inflammation in the walls of small airways
• ingrowth of granulation tissue –> airway obliterans –> slowly worsening dyspnea and dry cough –> months to years

Hyperacute lung rejection

• hemorrhagic/ischemia –> fibrinoic necrosis –> antibodies to donor HLA/ABO groups of donor

ACute lung rejection

• Ab to donor HLA. Cell mediated immune response
• perivascular mononuclear infiltrates –> expand into alveolar walls

Acute vs Chronic

• acute: pervascular mononuc infiterates
• chronic: submucosal lymphocytic inflammation

Endotoxic shock: Lipopolysaccharide –> Lipid A

Dendritiv/APC –> IL12 –> Th1 –> InfGamma/IL2 –> +Macs –> phaglolysosomes destroy bacteria particularly intracellular (TB) –> Tb.

• Tb Cavitation –> upperloabs –> takes months! (unlike abscess)