Question

HIV targets CD4+ white blood cells, leading to a gradual decrease of that cellular subpopulation an HIV-positive patient. Describe four impacts this may have on the adaptive immune system (8pts) and at least one potential impacts innate immune system (2pts). Note: not being able to make multiple kinds of cells only counts as one impact (ex. “Cell-type A, type B, and type C are not produced” all counts as one).

Answer 1

Impact on adaptive immune system

a) Activation of chronic immune system – The number of CD4+ and CD8+ T-cell, NK cell, and B cell population increases at a tremendous rate after getting infected with HIV virus. This leads to increased cell division

b) Induces production of viral gene factors such Nef, Tat, Vpr, and Vpu

c) High level of proinflammatory cytokines and chemokines such as I IFNs, IL-6, MIP-1β, RANTES etc.

d) Generation of non-neutralising antibodies to structural proteins such as P17 and P24 to prevent entry of the virus into the cells

Impact on Innate immune system

Reduced activity of natural killer cell with lytic activity. This is due to the reduced major histocompatibility complex (MHC) I antigens expression