Question

Antigen presenting cells link innate and adaptive immune responses. In the theoretical scenario where phagosomes cannot be formed, phagocytosis is made ineffective.

a. Could any APCs continue processing and presentation of an antigen in this scenario? How? Explain in less than 25 words.

b. Would any cytotoxic T cells activity be observed? Explain in less than 25 words.

c. Could any antibody production occur? If so, what class(es) could be made? Explain in less than 25 words.

Answer 1

a. Yes professional antigen presenting cells(APCs) like macrophages Phagocyte the exogenous antigen and fuse with endosome. Small fragments of this antigen express on the surface membrane of macrophages with the help of Major histocompatibility complex II (MHC II). So exogenous antigen presentation is done by this scenario.

b. No cytotoxic T cell involved in this type of presentation. As here MHC II molecule involved so it present antigen to the Helper T cell. Cytotoxic T Cell are involved in endogenous antigen presentation with MHC I molecule.

c. Yes antibody production occur when T cell stimulate B cells. The Plasma B cell produce first class of antibody that is IgM and the memory B cell memories the antigen which entered into the body.