Question

Caleb has a lung infection caused by the bacterium streptococcus pneumoniae an extracellular pathogen. what type of adaptive immune response will Caleb’s immune system have to the bacteria? summarize what is happening during this type of immune response

Answer 1

In bacterial pneumonia the innate response of the host is initiated by the lung epithelia signal through pattern recognition receptors promoting the activity of another innate immunity components such as: dendritic cells, alveolar macrophages and IL-17 production. On the other hand, the adaptive immune response is also important, characterized by CD4 T cells and B cells maturation and response.

The pathogens causing bacterial pneumonia (such as Streptococcus Pneumoniae) are able to stimulate both innate and adaptive response. In the case of CD4 T cells, the naïve precursors receives T cell receptor signal from class II restricted antigen (from the pathogen) leading to the differentiation into competent CD4 T cell to develop a host defense. On the other hand, the humoral immunity can be stimulated via antibody production by B cells once the antigen was presented and B cells proliferate.