HIV

HIV infection and immunity, specifically in the case of Mr. Timothy Ray Brown (“The Unluckiest Man in the World”). Here’s help with each question based on your worksheet:

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Q1: Why might Mr. Brown’s therapy stop working after years?

Answer:

HIV can mutate quickly, especially in its envelope proteins. This allows the virus to escape the effects of antiretroviral therapy (HAART). Over time, these mutations can lead to drug resistance, making the therapy less effective.

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Q2: What two host cell membrane proteins are involved in HIV entry?

Answer:

1. CD4 receptor (main receptor on helper T cells)
2. Co-receptor – either CCR5 or CXCR4

These are required for HIV to bind and fuse with the host cell membrane before entering.

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Q3: What immune cell does HIV infect?

Answer:

CD4+ T cells (also called Helper T cells)

HIV specifically infects these cells, which are central to immune system function. Their destruction leads to immune suppression and eventually AIDS if untreated.