Lipopolysaccharide induces retroviral antigen expression in 129/J mouse lymphocytes: evidence for assembly of a defective viral particle

In contrast to those of many other mouse strains, spleen cell cultures of 129/J mice do not release reverse transcriptase activity into the supernatant upon stimulation with bacterial lipopolysaccharide. We report here that lipopolysaccharide induced the expression of intracellular viral proteins in 129/J spleen cells. Furthermore, we found that stimulated spleen cells released retroviral particles. We conclude that 129/J mice are inducible with lipopolysaccharide but that the virus produced is a defective particle deficient in reverse transcriptase activity.