Calcium oxalate crystals are present in the vacuoles of many species, and may be distributed evenly throughout the leaf or restricted to specialized cells called idioblasts

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IFN-ϒ acts directly by inducing an antiviral state in nearby cells.

IL-2 acts indirectly by assisting the development of cytotoxic T lymphocyte(CTL) precursors into an effector population.

Both IL-2 and IFN-ϒ activate NK cells.

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Viruses Employ Several Different Strategies to Evade Host Defense Mechanisms

Hepatitis C virus, inhibiting the action of PKR.

Herpes simplex virus TAP.

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Adenoviruses and cytomegalo virus use to reduce the surface expression of class I MHC molecules, 

Measles virus and HIV, reduce levels of class II MHC molecules on the surface, 

Vaccinia virus, secreting a protein that binds to the C4b complement component.

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Influenza virus

Influenza are surrounded by an outer envelope, a lipid bilayer derived from the plasma membrane of the infected cell.

Viral specific Protein 

Hemagglutinin (HA) 

Neuraminidase (NA)

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HA trimers are responsible for the attachment of the virus to host cells, binding to the sialic acid. 

NA is an enzyme that cleaves N-acetyl neuraminic (sialic) acid

Within the envelope, consists of eight different strands of single- stranded RNA (ssRNA) associated with protein and RNA polymerase.