Disease relevance of Brucella

• Further observations on the inhibition of tumor growth by Corynebacterium parvum with cyclophosphamide. V. Comparison of the effects of tilorone hydrochloride, levamisole, methanol-soluble fraction of Mycobacterium butyricum, BCG, and a nonviable aqueous ether extract of Brucella abortus preparation in treatment of mice with tumors [1].
• We find that early RA patients have enhanced humoral and cellular immune responses to Epstein-Barr virus and Brucella ovis and Lactobacillus lactis antigens which contain the QKRAA sequence [2].
• Here we present crystal structures of VirB8 of Brucella suis, the causative agent of brucellosis, and ComB10, a VirB10 homolog of Helicobacter pylori, the causative agent of gastric ulcers [3].
• We have previously reported that, unlike Escherichia coli K12, intracellular pathogens from the genus Brucella survive and multiply within U937-derived phagocytes, and live Brucella organisms failed to induce TNF-alpha release upon infection [4].
• We have previously shown that immunization of mice with human immunodeficiency virus (HIV)-derived proteins or peptides conjugated to inactivated Brucella abortus induces the secretion of virus-neutralizing antibodies, predominantly of the immunoglobulin G2a (IgG2a) isotype [5].

High impact information on Brucella

• Brucella CbetaG is thus a virulence factor that interacts with lipid rafts and contributes to pathogen survival [6].
• Cellular prion protein promotes Brucella infection into macrophages [7].
• The nature of the Brucella HF-I-regulated genes that have been identified to date suggests that the corresponding gene products contribute to the remarkable capacity of the brucellae to resist the harsh environmental conditions they encounter during their prolonged residence in the phagosomal compartment [8].
• Structural comparison of pVirB8(AT) with Brucella suis VirB8 confirms that the monomers have a similar fold [9].
• Brucella coopts the small GTPase Sar1 for intracellular replication [10].

Chemical compound and disease context of Brucella

• We also found that lpsB mutants were sensitive to the cationic peptides melittin, polymyxin B, and poly-l-lysine, in a manner that paralleled that of Brucella abortus lipopolysaccharide mutants [11].
• The patient was also unable to develop normal humoral or cellular reactivity to brucella antigen, keyhole limpet hemocyanin, or dinitrochlorobenzene [12].
• Two chemicals, pyran copolymer and glucan, and one biological, Brucella abortus strain 456 ether extract, were shown to be strong stimulators of antitumor immunity [13].
• Brucella abortus lipopolysaccharide is mitogenic for spleen cells of endotoxin-resistant C3H/HeJ mice [14].
• The reversibility of the O-chain-antibody reaction was also demonstrated by showing a rapid depolarization of the labeled O-chain-antibody complex in the presence of unlabeled O-chain, suggesting that this displacement experiment could be exploited to quantify the Brucella polysaccharide antigen [15].

Biological context of Brucella

• The Brucella suis virB operon is induced intracellularly in macrophages [16].
• We propose that Sar1-dependent ERES functions, but not subsequent secretory events, are essential for the biogenesis of the Brucella replicative compartment and, thus, bacterial replication [10].
• We have previously shown that thyrotropin (TSH), which is produced by lymphocytes in response to the T cell mitogen staphylococcal enterotoxin A, enhances in vitro antibody production to T cell-dependent and independent Ag (SRBC and trinitrophenylated Brucella abortus [BA-TPN], respectively) as determined by a direct plaque-forming cell assay [17].
• These properties make lipopolysaccharide an important virulence factor for Brucella survival and replication in the host [18].
• Two putative proteins (NorMI and NorMII) similar to the multidrug efflux protein NorM of Vibrio parahaemolyticus are encoded by the Brucella melitensis 16 M genome [19].

Anatomical context of Brucella

• The present studies were designed to determine the possible immunoregulatory function of TSH on lymphocytes immunized with the T-independent antigen Brucella abortus-TNP (BA-TNP) and the cellular components involved in such function [20].
• For the first time in phagocytes, we thus characterized a primordial virulence strategy of Brucella involving the host signaling pathway, a novel point of immune intervention of this virulent pathogen [21].
• Our results show that T cell-depleted B cells precultured for 18 to 24 h with rabbit anti-Ig reagents are rendered unresponsive to challenge with either Ag, fluorescein coupled to Brucella abortus (FL-BA), or mitogen (LPS) [22].
• Ultrastructural morphometric analysis of Brucella abortus-infected trophoblasts in experimental placentitis. Bacterial replication occurs in rough endoplasmic reticulum [23].
• In this report we provide evidence, for the first time, that bacterial DNA in the context of heat-killed Brucella abortus (HKBA) engages TLR9 in dendritic cells (DC), resulting in a Th1-like cytokine response [24].

Gene context of Brucella

• Heat-killed Brucella abortus induces TNF and IL-12p40 by distinct MyD88-dependent pathways: TNF, unlike IL-12p40 secretion, is Toll-like receptor 2 dependent [25].
• Brucella abortus S2308-infected IRF-1-/- mice were dead within 2 wk postinfection, while IRF-2-/- mice contained less splenic Brucella CFU than wild-type mice at the early stage of infection [26].
• Infected ICSBP-/- mice maintained a plateau of splenic Brucella CFU throughout the infection [26].
• They also support the possibility that in mice, NO favors the elimination of Brucella, providing that IFN-gamma and antibrucella antibodies are present, i.e., following expression of acquired immunity [27].
• The intracellular, gram-negative pathogen Brucella abortus establishes chronic infections in host macrophages while downregulating cytokines such as tumor necrosis factor alpha (TNF-alpha) [28].

Analytical, diagnostic and therapeutic context of Brucella

• Immune responses and resistance to infection with Brucella abortus 2308 (S2308) were measured in mice following vaccination with B. abortus 19 (S19) or the lipopolysaccharide (LPS) O-antigen-deficient mutant, strain RB51 (SRB51) [29].
• Western blot (immunoblot) analysis of sera from cattle vaccinated with Brucella abortus S19 exhibit an elevated serologic response to Hsp62, the GroEL homolog (BaGroEL) [30].
• One- and two-dimensional gel electrophoresis and cellular immunoblotting were used to compare the protein profiles and immunogenic capabilities of salt- and sodium dodecyl sulfate-extracted components isolated from different Brucella species [31].
• Replacement of the wild-type exsA by recombination was demonstrated by Southern blot analysis of Brucella genomic DNA [32].
• Molecular cloning and characterization of cgt, the Brucella abortus cyclic beta-1,2-glucan transporter gene, and its role in virulence [33].

References