Effect of interleukin-1α on the growth of Mycobacterium microti within J774A.1 cells

Abstract The effect of mouse recombinant interleukin-1 α on the intracellular growth of Mycobacterium microti in a murine macrophage cell line J774A.1 was investigated. Interleukin-1 α added after infection to the M. microti -infected macrophage monolayers enhanced the growth of M. microti in a concentration-dependent manner and this growth enhancement was abrogated by neutralization of interleukin-1 α with anti-interleukin-1 α antibody. Cyclic adenosine monophosphate level in J774A.1 cells was increased by the addition of interleukin-1 α . Addition of dibutyryl cyclic adenosine monophosphate to infected J774A.1 cells increased the number of intracellular bacteria in a concentration-dependent manner. These results suggest that interleukin-1 α acts as a growth enhancer for intracellular M. microti and the growth enhancing effect of interleukin-1 α may be due to enhanced cellular cyclic adenosine monophosphate level.