B. pertussis

It seems likely that many such (recombinant) subunit vaccines will gain future regulatory approval. One such example is that of Bordetella pertussis subunit vaccine. B. pertussis is a Gramnegative coccobacillus. It is transmitted by droplet infection and is the causative agent of the upper respiratory tract infection commonly termed whooping cough . 

Fig. 14. Structural prediction and modeling of a fragment of FHA from B. pertussis containing Rl-repeats. (A) Successive stages in the modeling. From top to bottom identification of the consensus sequence repeat, generation of 2D template of the coil, and the modeled 3D structure. In the consensus sequence, letters indicate residues that are conserved at the level of >60% identity, x is any residue and filled circles represent bulky nonpolar residues. Apolar residues are in red glycine in green. In the 2D template, open circles denote any (but mainly polar) residues, while filled circles denote conserved, mainly nonpolar, residues. Circles inside the coil contour indicate side chains located inside the structure and circles outside the contour denote side chains facing the solvent. Arrows indicate /(-strands. (B) A fragment of the crystal structure of FHA (Clantin et al, 2004) (on the top, in green color) and the 3D model (bottom, in brown).

In a few cases, 3-hydroxy fatty acids that contain additional functional groups were characterized. Thus (i )-3-hydroxydodec-(5Z)-enoic add [A5-12 l(3-OH)] was identified in ester linkage in lipid A of the chloridazon-de-grading bacterium P. immobile (105). Unsaturated 3-hydroxy fatty adds are also present in R. trifolii (81) and R. meliloti (82). In an extract of L. pneumophila, 2,3-dihydroxy-12-methyltridecanoic acid [12-Me-13 0(2,3-diOH)] and 2,3-dihydroxytetradecanoic acid [ 14 0(2,3-diOH)] were identified in amide-linkage (138). It remains, however, to be established, whether these 2,3-dihydroxylated fatty acids are lipid A constituents. Small amounts of 2-methyl-3-hydroxy-fatty adds have been detected in B. pertussis (139). 

For the analysis of fatty acids amide-linked to GlcN(I), several chemical degradation procedures are available. One comprises periodate oxidation of 0-deacylated and 2H-reducedlipid A (lipid A-OH ). Following permethyl-ation, g.l.c.-m.s. analysis revealed a 2-deoxy-1 -deuterio-1,3-di-O-methyl-2-(iV-methyl-3-methoxyacylamido)glycerol derivative in which the amide-finked fatty acid at GlcN(I) was identified as 14 0(3-OH) in B. pertussis (93), and as 16 0(3-OH) and 18 0(3-OH) in R. trifolii 81). 

Pertussis (whooping cough) B. pertussis 40 to 50 mg/kg/day, given in divided doses 5 to 14 days... 

Similarly, ADP ribosyiation of the a subunit ofG, caused by pertussis toxin in the epithelial cells lining the airways of patients having a B pertussis infection inhibits exchange of GDP for GTP that ordinarily activates G,. 

A number of B. pertussis (polypeptide) antigens have been expressed in E. coli and other recombinant systems. Several of these are being evaluated as potential subunit vaccines, including B. pertussis surface antigen, adhesion molecules and pertussis toxin. Pertussis toxin has been shown to protect mice from both aerosol and intracerebral challenge with virulent B. pertussis. The bacterial proteins that mediate surface adhesion protect mice from aerosol but not intracerebral challenge. Future pertussis subunit vaccines may well contain a combination of two or more pathogen-derived polypeptides. 

Genetic manipulation of B. pertussis has resulted in acellular toxoids which are claimed to be devoid of toxicity, and acellular vaccines have been introduced in the United States and Japan for the treatment of older children. Trials have demonstrated that the efficacy of acellular vaccines is comparable to whole-cell vaccines but have virtually no side effects. 

Some bacteria produce effects similar to those of cholera toxin in different ways. For example, among a variety of toxic proteins produced by Bacillus anthracis, the causative agent of anthrax, is an adenylate cyclase that is able to enter the host s cells.s Similarly, B. pertussis, in addition to... 

The necessity of establishing the presence of a structural element present in many endotoxins may be questioned, but it should be remembered that B.pertussis is a rather singular microorganism in every respect (6) whose classification itself is uncertain, and it has been observed by MacLennan, who first isolated this endotoxin (7), that the lethal toxicity of this material was considerably lower than that of enterobacterial endotoxins, an observation confirmed by both Kasai (8) and Nakase ( ). 

One such assay is based on the synthesis of adenosine 3 ,5 -cydic monophosphate (cAMP) by adenylate cyclase [59]. The adenylate cyclase from B. pertussis can be split into two functionally complementary fragments, T18 and T25, allowing protein dimerization to be assayed based on dimerization of T18 and T25 and reconstitution of... 

Various bacterial vectors have been used to express a number of bacterial B. pertussis, S. pneumoniae, Y. pestis, and L. monocytogenes), viral (herpesvirus, influenza virus, human immunodeficiency virus, simian immunodeficiency virus, and hepatitis B virus), and parasitic (5. mansoni, and L. major) antigens. Significant improvements in attenuation of bacteria, and the stability, localization, and expression levels of heterologous antigens are required to market the bacterial vector-based vaccines for use in humans or animals. 

Bordetella pertussis for use with alum-precipitated proteins B. pertussis is heat-inactivated and mixed with alum-... 

Acellular pertussis vaccines contain selective components of the B. pertussis organism. All acellular vaccines contain pertussis toxin (PT), and some contain one or more additional bacterial components (e.g., filamentous hemagglutinin [FHA], pertactin [a 69-kDa outer membrane protein], and fimbriae types 2 and 3). Acellular pertussis vaccine is recommended for all doses of the pertussis schedule at 2, 4, 6, and 15 to 18 months of age. A fifth dose of permssis vaccine is given to children 4 to 6 years of age. Pertussis vaccine is administered in combination with diphtheria and tetanus (DTaP). Although the permssis vaccine is not recommended for individuals 7 years of age and older, booster doses for adolescents and adults may be incorporated into future recommendations because members of these groups are important reservoirs of infection. 

G proteins typically are activated by a ligand-stimulated receptor and act as a primary signal transducer. The presence of these proteins in mammalian and nonmammalian sperm was first detected in assays of the ribosyltransferase activity of b. pertussis exotoxin (Bentley et al., 1986 Kopf et al., 1986). A number of a subunits are expressed during mammalian spermatogenesis, including members of the pertussis toxin- sensitive G group and G , as well as the pertussis toxin-insensitive G /j, and G (Glassner et al., 1991 Karnik et al., 1992 Ward and Kopf, 1993 Walensky and Snyder, 1995). 

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