Immune and mitogenic responses by BALB/c, C3H/HeJ, and nude mice to Brucella abortus bacterin and lipopolysaccharide

Abstract

The immunogenic and mitogenic properties of Brucella abortus 1119-3 bacterin (BA) and biologically active B. abortus lipopolysaccharide (BA-LPS) were studied using normal and athymic (nude) BALB/c and C3H/HeJ mice. Although BA stimulated 2-mercaptoethanol-sensitive (2-ME-S) primary and secondary antibody responses in all mice, nude mice, in contrast to normal BALB/c and C3H/ HeJ mice, did not make substantial 2-mercaptoethanol-resistant (2-ME-R) antibody responses. Similarly, all mice injected with BA-LPS made 2-ME-S primary responses, and the secondary response of thymus-bearing mice contained a substantial 2-ME-R component. Collectively, these observations suggest that although both BA and BA-LPS can stimulate thymus-independent 2-ME-S antibody synthesis, thymus-derived cells are required for optimal immune responses containing a 2-ME-R component. The antibody responses of normal BALB/c and C3H/HeJ mice to BA and BA-LPS were qualitatively and quantitatively similar. Both BA and BA-LPS were mitogenic for spleen cells from normal and nude BALB/c and C3H/HeJ mice but not for thymus cells from normal BALB/c or C3H/HeJ mice, suggesting that both preparations are B-cell mitogens.There are conflicting reports (5,12,16,21,37) about the ability of the brucellae to elicit the biological and immunological responses evoked by the Enterobacteriaceae. These early reports, based on various animal models, either confirmed or denied the cytotoxic, pyrogenic, and antigenic properties of killed Brucella abortus cells (BA) or B. abortus lipopolysaccharide (BA-LPS). The properties attributed to the BA-LPS were further clouded because different investigators have used products ofvarious purification procedures as the endotoxin preparation. In 1960, Redfearn (Ph.D. thesis, Univ. of Wisconsin, Madison, Wisc.) reported that, unlike enterobacterial LPS which partitions into the aqueous-phase, BA-LPS extracted by the Westphal procedure partitions into the phenol phase. Leong et al. (16) thoroughly documented that this phenol-phase-extracted BA-LPS shares many of the physiological, structural, and chemical properties of aqueous-phase-extracted enterobacterial LPS. Their results also indicated homology between BA-LPS and Escherichia coli LPS.Although many immunological responses by animals to endotoxin preparations from the Enterobacteriaceae have been well characterized (7,9,15,24,27,35), investigation of the immu-nological properties of BA-LPS has been largely neglected. We have studied several aspects of the immunological response by mice and mitogenic responses of murine cell cultures to BA and BA-LPS in light of several known immunogenic characteristics of E. coli bacterin and LPS. Congenitally athymic (nude) mice were used to investigate the role of T lymphocytes in the response to both BA and BA-LPS. C3H/ HeJ mice, shown to have a genetically controlled low response to the endotoxins of E. coli and Salmonella (27,30,32,36) were included in these studies to determine if this genetic defect would also limit the C3H/HeJ response to BA ...

Characterization of Biological Activities of Brucella melitensis Lipopolysaccharide

“…Experimental results in the present study also suggests that B. melitensis and B. abortus LPSs may exhibit similar biological actions. Interestingly, B. abortus LPS can activate spleen cells from LPS-resistant C3H/HeJ mice (28,32). However, it could not necessarily be reproduced by our preparation of B. melitensis LPS (data not shown).…”

Induction of immune and adjuvant immunoglobulin G responses in mice by Brucella lipopolysaccharide

“…Comparative investigations, both in vivo and in vitro, with endotoxin preparations from different organisms which have different properties should also prove useful. For example, Spellman and Reed (40) have reported that a crude preparation of B. abortius LPS induced "T-independent" primary IgM responses and "TD" secondary responses in both euthymic BALB/c and C3H/HeJ mice as determined by 2-mercaptoethanol sensitivity of the bacterial agglutinins. Athymic BALB/c mice also made secondary responses with some mercaptoethanol-stable agglutinin.…”

Lipopolysaccharides (LPS) of Oral Black-Pigmented Bacteria Induce Tumor Necrosis Factor Production by LPS-Refractory C3H/HeJ Macrophages in a Way Different from That ofSalmonellaLPS

“…While C3H/HeJ cells are profoundly refractory to some highly purified LPS, however, the cells remain responsive to other endotoxins (e.g., Boivin) in which the endotoxin protein or lipid A-associated protein (35) is known to be bioactive. In addition, LPS from Brucella abortus (21,33), Pseudomonas aeruginosa (29), Porphyromonas (Bacteroides) gingivalis (5,7), and Bacteroides fragilis (12) are also known to activate C3H/HeJ cells. LPS isolated from rough (R-form) mutant members of the family Enterobacteriaceae had also been thought capable of stimulating C3H/HeJ cells, but Manthey and Vogel (19) clearly demonstrated that the effect disappeared when protein associated with the LPS was removed by repurification.…”