Question

A 5 year-old patient presents to his pediatrician with another of what has been a series of infections. Flow cytometry of the boy's blood reveals that the patient is severely deficient in CD4 T cells. CD8 T cells and B cells are at normal levels. Which of the following statements would be true for this patient's case? Select all that apply.

A.) T-cell dependent activation of B cells is not occurring in the patient.

B.) The patient's immune system will only be able to respond to T-dependent antigens

C.) The patient is only able to activate CD8 T cells and will therefore only respond to intracellular pathogens.

D.) T-cell dependent activation of B cells is occurring in the patient.

E.) T-cell independent activation of B cells is occurring in the patient.

F.) The patients immune system will only be able to respond to T-independent antigens.

Answer 1

Statement A and E are correct. In option A as helper T cells when activated they release cytokines to activate B cell. As patient is deficient in CD4+ T cells; only possible way should b T independent activation of B cell. Same states the statement E.

Statements B is incorrect as CD4+ cells are unable to activate but B cells activates.

Statement C is not true as B cells also respond to soluble antigens.

Statement D is incorrect as no helper cells are present.

Statement F is incorrect T_c​​​​​​ cells responds to T dependent intracellular pathogens.