BIOL 104 Lecture Notes - Lecture 9: Antigenic Shift, Neuraminidase, Reassortment
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I(cid:374)flue(cid:374)za ((cid:862)the flu(cid:863: fro(cid:373) the italia(cid:374) (cid:449)ord for (cid:862)i(cid:374)flue(cid:374)(cid:272)e(cid:863, 30,000 us deaths/year, 100,000 hospitalizations/year. Some people have higher susceptibility: elderly (>65 years, children (<2 years, pregnant women, the immune-compromised. Some cells become memory cells that (cid:862)re(cid:373)e(cid:373)(cid:271)er(cid:863) the a(cid:374)tige(cid:374: this is why you only get some viral infections once (chicken pox) Va(cid:272)(cid:272)i(cid:374)es (cid:862)pri(cid:373)e(cid:863) your i(cid:373)(cid:373)u(cid:374)e syste(cid:373) (cid:449)ith (cid:448)iral a(cid:374)tige(cid:374)s. Why do you have to keep getting flu shots: the virus keeps changing! Influenza changes through two mechanisms: antigenic drift, antigenic shift. There are multiple types of na and ha proteins: neuraminidase (na) n1-n9, hemagglutinin (ha) h1-h16 (cid:862)a(cid:374)tige(cid:374)i(cid:272) drift(cid:863, the (cid:448)iral poly(cid:373)erases (cid:373)ake a lot of errors i(cid:374) the ha a(cid:374)d na rnas ((cid:374)o (cid:862)proofreadi(cid:374)g(cid:863)) The virus contains 8 strands of rna in its genome: 8 genes code for 11 proteins. What happens if two different viruses infect this cell: the virus that buds off is different from the virus that enters.
