The role of natural killer cells and lymphokine activated killer cells in the pathogenesis of hepatic injury in hepatitis A [corrected].

In order to clarify the mechanism of liver damage in hepatitis A, we studied the role of Natural Killer (NK) cells and Lymphokine Activated Killer (LAK) cells in non-specific immunological reactions using hepatitis A (HAV) infected cells (JTC-12.P3 cell) using the 51Cr release assay. No significant difference in specific cytotoxicity was observed between uninfected cells (JTC) and HAV-infected cells (JTC-HAV) to fresh and Poly I:Cor rIL-2 pretreated peripheral blood mononuclear cells (PBMC) from healthy donors or patients with acute hepatitis A. But in an experiment employing fresh and rIL-2 pretreated PBMC from cynomolgus monkey as effectors, a significant difference in NK and LAK sensitivity between JTC and JTC-HAV was noticed. Cytotoxicity assay was then carried out using as effectors fresh or rIL-2 pretreated cells of B, NK and T cell fractions obtained after separation of PBMC from monkey by the E-rosette formation method. Both fresh and rIL-2 pretreated B/NK cells showed significantly higher cytotoxicity for JTC-HAV than JTC, but neither fresh or rIL-2 pretreated T cells showed cytotoxicity for JTC-HAV or JTC. These results imply that both NK and LAK cells may play a part in the mechanism of hepatocellular injury.