Increased Resistance to Infection and Accompanying Alteration in Properdin Levels Following Administration of Bacterial Lipopolysaccharides

Abstract

The attention of immunologists has long been focused on acquired immunity produced by specific antigens. In the classical sense this type of immunity to infection, which generally is of a high order, depends upon the appearance of protective antibodies. The obvious importance of such artificial immunity, and the relative ease with which these antigens and antibodies could be studied, contributed to the comparative neglect of other components of bacterial cells which may also give rise to protective reactions. Nevertheless, it has been recognized that there is also a type of resistance which transcends the limits of antigenic specificity, and from time to time this kind of protection against infection was observed even though demonstrable antibodies could not be detected. In fact it was noted by a number of workers that the injection of various substances of bacterial and of other origin produced an increase in normal resistance. While the level of resistance thus achieved was lower than that which followed the injection of specific immunizing agents, it was sufficient to indicate that it might nonetheless contribute to immunity.These observations extend back to some of the early work in microbiology and were first brought together by Kolle and Prigge (1). The more recent literature has been assembled by Brandis (2) who also reported the rapid production of a protective effect against challenge with Salmonella derby by the injection into mice of a number of bacterial vaccines or unrelated products. He called this effect "proimmunity" and considered it to be a result of non-specific stimulation of the cellular defenses of the host. Rowley (3) showed that mice injected with cell walls of Esckerichla coil, Salmonella typhimurlum, or zyrnosan (4), within the first few hours were more susceptible than normal mice to challenge with E. coll.

Improved Innate Immunity of Endotoxin-Tolerant Mice Increases Resistance toSalmonella entericaSerovar Typhimurium Infection despite Attenuated Cytokine Response

“…Published data are conflicting as to the activity of the complement system in endotoxin tolerance (24,36). Since it is feasible that an increase in complement activity in the course of an acute-phase response elicited by endotoxin administration could account for improved phagocytosis in our model, we determined complement activity (50% hemolytic complement values) of sera from LPS-tolerant and control mice.…”

Functional role of antibody against "core" glycolipid of Enterobacteriaceae.

“…with four additional 3-ml injections given each time to dogs and 0.5 ml to rabbits i.v. All animal challenge experiments were carried out more than 1 wk after completion of immunization to minimize "nonspecific" protective effects secondary to administration of lipopolysacchari(les (10,19,20).…”

Understanding How Lipopolysaccharide Impacts CD4 T-Cell Immunity

“…As reviewed elsewhere, LPS initially gained interest as the component of gram negative bacteria responsible for toxicity and pyrogenicity, 3 but later studies revealed that it could generate protection from subsequent infection that correlated with increased antibody levels. [4][5][6] Findings that LPS-unresponsive mice are susceptible to gram-negative infections further highlighted the importance of this molecule in immune protection. 3 Therefore, a large body of research has been devoted towards investigating the adjuvant effects of LPS on lymphocytes.…”