RT Journal Article
SR Electronic
T1 Bacterial induction of human activated lymphocyte killing and its inhibition by lipopolysaccharide (LPS).
JF The Journal of Immunology
JO J. Immunol.
FD American Association of Immunologists
SP 2662
OP 2669
VO 136
IS 7
A1 Tarkkanen, J
A1 Saxén, H
A1 Nurminen, M
A1 Mäkelä, P H
A1 Saksela, E
YR 1986
UL http://www.jimmunol.org/content/136/7/2662.abstract
AB Peripheral blood lymphocytes were incubated with glutaraldehyde-fixed Salmonella bacteria. This resulted in rapid activation of nonspecific cytotoxic potential of the lymphocytes. Both originally noncytotoxic, high-density Percoll-fractionated cells, and cytotoxic natural killer (NK) cell-enriched low-density cells were activated. The induction of originally noncytotoxic cells into activated killer (AK) cells was apparently independent of interferon (IFN), whereas the activation of the NK cell-enriched fractions also involved IFN production. Neither the AK nor NK activity were associated with significant bactericidal activity. The IFN-independent induction of AK activity was not dependent on the O-antigenic polysaccharide part of the lipopolysaccharide (LPS) on the bacterial cell surface, because both smooth (S) strains with differing O-antigenic structures (S-4,12 and S-6,7) and a rough (Re) strain without O-antigen were effective inducers. Isolated LPS, and especially alkali-hydrolyzed (O-deacylated, detoxified) LPS (ALPS) interfered with the induction of cytotoxicity. At concentrations of 10 to 30 micrograms/ml, ALPS totally inhibited the induction of AK activity without affecting the endogenous NK activity. Thus contact with bacteria can lead to the emergence of AK cells, and a bacterial product can effectively block this activation. These phenomena stress the complexity of interactions with host defenses that can take place during bacterial infection.