Question

Question 1: Describe what is happening during the latency period of an HIV infection. Is latency a misnomer?

Question 2: How does a drop in the number of CD4+T cells result in immunodeficiency? What parts of the immune system are affected?

Question 3: How does the immune system response create the severe symptoms of bacterial meningitis? What are some consequences?

Answer 1

ANS :

Latency Period

About 6 weeks after HIV infection, a stage with no signs or symptoms, known as the clinical “latency” period. During this stage there is a very slow reduction in the number of CD4 T cells with time, and an associated gradual increase in the amount of HIV particles in the body

ANS :A severe decrease of CD4 T cells predisposes humans to opportunistic infections. In adults, HIV is certainly the most common cause of CD4 lymphocytopenia, but other causes, such as infections, autoimmune diseases, immunosuppressive therapy, lymphoma and idiopathic forms need to be considered.immunodeficiency syndrome (AIDS) pathogenesis is a progressive depletion of CD4+ T-cell populations in close association with progressive impairment of cellular immunity and increasing susceptibility to opportunistic infections (OI). Disease progression in untreated human immunodeficiency virus (HIV) infection can take many years, and it was originally hypothesized to be a consequence of slow, viral-mediated CD4+ T-cell destruction. However, massive CD4+ memory T-cell destruction is now known to occur quite early in infection, almost always without overt immunodeficiency. In most individuals, this initial destruction is countered by CD4+ memory T-cell regeneration that preserves CD4+ T-cell numbers and functions above the threshold associated with overt immunodeficiency.

ANS : Bacterial meningitis is very serious and can be deadly. Death can occur in as little as a few hours. Most people recover from meningitis. However, permanent disabilities (such as brain damage, hearing loss, and learning disabilities) can result from the infection. bacterial meningitis mimic human cells to evade the body's innate immune system has been revealed. Meningitis involves an inflammation of the membranes covering the brain and the spinal cord as the result of an infection