Immunity to lentiviruses

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APOBECS - family of proteins (cytidine deaminases) - innate immunity

Lentiviruses have protein they use specifically to block APOBECS

Viral particle infects cell with APOBECS and cause the cells to make mistakes when replicating

*lions have 2 APOBECS that can inhibit lentiviruses (lions have evolved ability to control infection more efficiently than cats)

TRIM5 - binds to caspid and reduces the susceptibility of cells to infection of lentiviruses (drags virus away from destruction) - restricts HIV

Tetherin - stops virus from getting out - limites infection to one cell = stops spread (sticks across the bridge and stops membranes from coming apart - prevents budding)

*HIV is doubly adapted to circumvent immunity - has antagonist of tetherin and APABECS

Post infection - branching of new viral species

- cat does not only have one virus - has whole host of mutated viruses circulating its body

- resistant to neutralising antibodies - mutated sufficiently

- within the same cat, some viruses are neutralised and some are not

- virus keeps changing and evolving in order to evade the antibody

*virus has exposed loop on its surface, and is able to deliberately make mistakes when copying that sequence = infinitely variable