Which cells of the immune system are affected by HIV and leukemia and what parts of the immune response do these cells influence?

HIV primarily targets CD4+ T cells, which are crucial for orchestrating the immune response by helping activate B cells and cytotoxic T cells. In leukemia, particularly acute lymphoblastic leukemia (ALL), abnormal proliferation of lymphoid progenitor cells affects various immune cells, including B and T lymphocytes, leading to impaired immune function. Both conditions compromise the body's ability to mount effective immune responses, increasing susceptibility to infections and impacting overall immunity.