A 7 month old infant has chronic diarrhea, oral candidiasis, and recurrent viral and bacterial respiratory infections. Flow cytometry shows normal B cell count, low CD4 positive T cells, and markedly decreased expression of MHC class II molecules on antigen presenting cells. Which of the following processes is most directly impaired?
- A)Membrane attack complex formation
- B)Presentation of endogenous antigen to cytotoxic T cells
- C)Presentation of exogenous antigen to helper T cellsGABARITO
- D)V(D)J recombination
- E)Generation of reactive oxygen species in neutrophils
Explicação
MHC class II deficiency, also called bare lymphocyte syndrome type II, prevents antigen presenting cells from presenting exogenous peptides to CD4 positive helper T cells. Without helper T cell activation, both cellular and humoral immune responses are profoun... Ver explicação completa e trilha adaptativa →