Question

Once an infection begins, a pathogen has passed the passive barriers, and the human immune response kicks in. This is a multifaceted and complex series of interactions and possibilities. I want you to explain how two responses could have occurred and will likely proceed. (a) a virus is quickly opsonized and consumed by a macrophage. (b) a bacterial pathogen you have never encountered bumps into one of your B-cells that possesses a matching antibody (what happens next)

Answer 1

a.

After the virus is quickly opsonised and consumed by macrophage , two of the either things can happen; It successfully destroys the virus or the virus can trip it and use its machinery to replicate itself and spread infection.

It is engulfed using phagosome where the pH is lowered to to kill the virus, but in some cases the virus uses its to its advantage and escapes to cytoplasm.

b. a bacterial pathogen you have never encountered bumps into one of your B-cells that possesses a matching antibody (what happens next)

after that your adaptive immunity gets activated , either cell mediated immunity ( where T cells gets activated) , or humoral immunity ( where B cells get activated).

In this humoral immunity there B cells have antibodies to recognise the pathogens that our body encounters. They work as memory B cells too and stop from infection of the same pathogen if ever re-entry happens.