Gamma interferon and interleukin 2, but not interleukin 4, are detectable in γ/δ T-cell cultures after activation with bacteria

Abstract

Mycobacterium tuberculosis- or group A streptococcus-activated γ/δ T cells from normal healthy individuals were negatively sorted and restimulated in vitro for 48 h. Significant amounts of gamma interferon were detected after restimulation with M. tuberculosis, group A streptococci, or Listeria monocytogenes. In contrast, interleukin 4 was undetectable in the culture supernatants. Our findings provide indirect evidence for the involvement of γ/δ T cells in immunity against tubercle bacilli and probably other bacteria.