Involvement of HLA-DR+ large granular lymphocytes in the induction of tumor necrosis factor by Mycobacterium avium-intracellulare complex

Expansion of large granular lymphocytes following Pseudomonas infection in a patient with adult-onset Still's disease

We report a patient who had a 4-year history of adult-onset Still's disease (AOSD) and showed a prominent increase in large granular lymphocytes (LGL) when she developed severe Pseudomonas conjunctivitis due to Pseudomonas aeruginosa, skin eruptions, liver damage, and abnormal findings in coagulation studies, without any evidence of active viral activation, hemophagocytosis, or malignancies. The increased LGL cells were CD3(+)CD8(+), and disappeared promptly after the administration of antibiotics combined with prednisolone, with subsequent stabilization of her general condition.

Mycobacterial induction of activated killer cells: possible role of tyrosine kinase activity in interleukin-2 receptor alpha expression

Mycobacterium avium is an intracellular opportunistic pathogen commonly seen in AIDS patients. M. avium-infected monocytes have been recently shown to be lysed by interleukin-2 (IL-2)-activated killer cells. Since some bacterial products can directly augment natural killer activity, we examined the ability of these microorganisms to induce killer cell activity. Coculture of M. avium with large granular lymphocytes (LGL) was found to augment the ability of LGL to lyse both tumor cells and bacterially infected autologous monocytes. The induction of tumoricidal activity by M. avium was only partially neutralized by the presence of anti-IL-2 antibodies, indicating that both IL-2-dependent and IL-2-independent mechanisms are responsible for activation of killer cells. Furthermore, only the direct interaction between bacterium and LGL could induce the expression of both IL-2 receptor alpha protein and mRNA, an effect which was abrogated by the presence of genistein, a tyrosine kinase inhibitor. Thus, M. avium was seen to induce killer cells, an activity that is concomitant with the up-regulation of IL-2 receptor alpha, or Tac antigen, expression and which involves signal transduction mechanisms mediated by tyrosine kinase activity.