ABSTRACT
Selected parameters of cellular immunity relating to cytokine gene activation and responsiveness to interleukin-2 (IL-2) were analyzed in 27 patients with active pulmonary tuberculosis and no human immunodeficiency virus type 1 infection. Cytokine mRNAs were not expressed by peripheral blood mononuclear cells (PBMC) of normal controls. In PBMC of tuberculosis patients, messages for IL-1, IL-8, and tumor necrosis factor-alpha were uniformly expressed, whereas PBMC of only 5 of 18 patients expressed IL-6. PBMC of 7 patients (all of those with systemic symptoms) expressed interferon-gamma mRNA and none expressed IL-2 mRNA. Most patients' cells demonstrated IL-4 mRNA. Limiting dilution analysis of IL-2-responsive cells in PBMC revealed that tuberculosis patients had 10-fold fewer IL-2-responsive cells than did controls.
Subject(s)
Cytokines/biosynthesis , Cytokines/genetics , Gene Expression Regulation , Interleukin-2/pharmacology , Tuberculosis, Pulmonary/immunology , Cytokines/blood , Gene Expression Regulation/drug effects , Humans , Immunity, Cellular , Leukocyte Count , Lymphocytes/drug effects , Lymphocytes/immunology , Lymphocytes/metabolism , RNA, Messenger/biosynthesis , RNA, Messenger/isolation & purification , Reference Values , Transcriptional Activation , Tuberculin Test , Tuberculosis, Pulmonary/blood , Tuberculosis, Pulmonary/geneticsABSTRACT
We have established a long-term culture system to study macrophages chronically infected with mycobacteria. Monocytes are infected with Bacillus Calmette-Guerin (BCG) and support exponential intracellular replication without profound perturbation of normal host cell function. We have used this system to investigate lymphokine-activated killer (LAK)-mediated cytolysis. We have found that interleukin 2 stimulation of peripheral blood lymphocytes generates a cytotoxic activity against human monocytes. A CD56- subpopulation of LAK cells specifically recognizes and lyses BCG-infected cells. Lysis of the host cell has no effect on parasite viability and results in the liberation of bacteria capable of infecting more cells.
