Neurons induce an immune response during M. tuberculosis infection. HT22, Neuro-2a, and primary neuronal cultures were infected with M. tuberculosis, and IL-1β, IL-6, and IL-10 were measured in the culture supernatants after 48 h by ELISA. The results represent the means and SD of combined data from 4 to 6 experiments; each experiment was performed in triplicate. ND, not detected.