The immune system, despite its immense complexity, really has only a few ways to kill bacteria:

• Neutrophils and macrophages can capture and digest extracellular bacteria (ones that live free in tissues and the bloodstream).
• Peptides (protein fragments) can punch holes in bacterial membranes or cross the membranes to disrupt bacterial processes.
• T-cells can kill cells infected by intracellular bacteria (ones that take up residence within cells).

It’s this last mechanism that I want you to pay attention to. The conventional wisdom has long held that T-cells can only kill intracellular bacteria indirectly by eliminating the cells they’ve infected. But a paper by Judy Lieberman, MD, PhD, of Boston Children’s Hospital’s Program in Cellular and Molecular Medicine, reveals that T-cells have a hitherto unnoticed way of directly killing intracellular bacteria And she only found it because of HIV/AIDS. …