Passive protection with immunoglobulin A antibodies against tuberculous early infection of the lungs.

We report on a new approach toward protection against tuberculosis, based on passive inoculation with immunoglobulin A (IgA) antibodies. In a mouse model of tuberculous lung infection, intranasal inoculations of mice with an IgA monoclonal antibody (mAb) against the alpha-crystallin antigen of Mycobacterium tuberculosis reduced up to 10-fold the lung bacterial counts at nine days after either aerosol- or intranasal challenge. This effect involved synergism between mAb inoculations shortly before and 3 days after infection.

Infection of macaques with simian immunodeficiency virus induces a species-specific antibody response to major histocompatibility complex class I and class II molecules.

Envelopes of retroviruses, including human immunodeficiency virus and simian immunodeficiency virus (SIV), contain host cell proteins that potentially represent novel targets for vaccine development. We show here that sera from rhesus macaques recognized simian major histocompatibility complex (MHC) molecules in response to infection with SIV. Antibodies from these animals did not cross-react with human MHC antigens on mitogen-activated peripheral blood mononuclear cells.

Bacillus amyloliquefaciens orthologue of Bacillus subtilis ywrO encodes a nitroreductase enzyme which activates the prodrug CB 1954.

A nitroreductase with distinct properties that can activate the prodrug 5-aziridinyl-2,4-dinitrobenzamide (CB 1954) was isolated from Bacillus amyloliquefaciens. The encoding gene was identified as a homologue of the ywrO of Bacillus subtilis, and was obtained as a PCR product by reverse genetics, cloned and the entire nucleotide sequence determined. The gene was found to reside between homologues of the B.

Induction of immunity using oral DNA vaccines expressing the measles virus nucleocapsid protein.

In this study, we have examined the feasibility of immunisation against measles with plasmid DNA administered by the oral route. After the oral administration, in two 50 microg doses, of poly(DL-lactide-co-glycolide) (PLGA)-encapsulated DNA expressing measles virus nucleoprotein, increasing titres of N-specific serum IgG antibodies were observed in three of ten C3H/He mice over a period of three months. In comparison, oral vaccination of mice with a replication-defective recombinant adenovirus expressing the same transgene induced serum IgG in all animals tested.

Induction of simian immunodeficiency virus (SIV)-specific CTL in rhesus macaques by vaccination with modified vaccinia virus Ankara expressing SIV transgenes: influence of pre-existing anti-vector immunity.

A major aim in AIDS vaccine development is the definition of strategies to stimulate strong and durable cytotoxic T lymphocyte (CTL) responses. Here we report that simian immunodeficiency virus (SIV)-specific CTL developed in 4/4 macaques following a single intramuscular injection of modified vaccinia virus Ankara (MVA) constructs expressing both structural and regulatory/accessory genes of SIV. In two animals Nef-specific responses persisted, but other responses diminished and new responses were not revealed, following further vaccination.

Comparison of large-scale mammalian cell culture systems with egg culture for the production of influenza virus A vaccine strains.

Different types of microcarriers were assessed for the large-scale culture of influenza virus in the Madin-Darby canine kidney (MDCK) cells. Both porous and solid carriers were examined. A higher titre of influenza A/PR8/34 virus was recovered from cultures using solid (1.

Tyrosine-1290 of tetanus neurotoxin plays a key role in its binding to gangliosides and functional binding to neurones.

Tetanus toxin acts by blocking the release of glycine from inhibitory neurones within the spinal cord. An initial stage in the toxin's action is binding to acceptors on the nerve surface and polysialogangliosides are a component of these acceptor moieties. Using site-directed mutagenesis, we identify tyrosine-1290 of tetanus toxin as a key residue that is involved in ganglioside binding.

Development of oral vaccines for human use.

In developed and developing countries, oral vaccine formulations that elicit protection at mucosal surfaces are attractive vaccine candidates. Research has shown that vaccine delivery using either viral or non-viral vector delivery of heterologous proteins via the oral route is highly effective. Improvements in non-viral vector uptake, specific targeting, antigen presentation and antigen release times will be required to overcome differences in the immune response following delivery.

Mucosal exposure to subinfectious doses of SIV primes gut-associated antibody-secreting cells and T cells: lack of enhancement by nonneutralizing antibody.

It has been suggested that the presence of immunoglobulin and complement receptors on rectal epithelium may facilitate the entry of HIV complexed to nonneutralizing antibody. We tested this hypothesis using simian immunodeficiency virus (SIV) infection of rhesus macaques. First, in a pilot study, a nonneutralizing IgG fraction of macaque anti-SIV gp120 was shown to enhance the immunogenicity of SIV envelope following rectal immunization.

Invasiveness in chickens, stress resistance and RpoS status of wild-type Salmonella enterica subsp. enterica serovar typhimurium definitive type 104 and serovar enteritidis phage type 4 strains.

The heat and acid resistance and the ability to survive airdrying on commonly used kitchen surfaces were assessed for clinical and environmental strains of Salmonella enterica subsp. enterica serovar Typhimurium, definitive type (DT) 104. Three out of thirty-eight strains of DT 104 were found to be more sensitive in stationary phase to the stresses examined than the other strains.

Progressive maturation resistance to microcystin-LR cytotoxicity in two different hepatospheroidal models.

To develop three-dimensional (3D) cytotoxicity models further, microcystin-induced cytoskeletal disruption was tested in two different models of multicellular hepatocyte aggregate formation (hepatospheroids). Rat hepatocyte suspensions were seeded either onto poly(2-hydroxyethylmethacrylate)-treated culture wells (poly-HEMA) or in a rotating wall vessel (RWV) device which provides minimal shear forces and enhances differentiated 3D growth. Ninety percent of spheroids forming on poly-HEMA tended to fuse and form nonhomogeneous multilobular structures by day 4 of incubation.

Comparison of the immunological and protective responses elicited by microencapsulated formulations of the F1 antigen from Yersinia pestis.

Purified native F1 antigen from Yersinia pestis was used to assess controlled-release vaccine delivery systems in poly(lactide-co-glycolide) (PLG) microparticles and liposomes. Antigen encapsulated in PLG microparticles induced high serum titres when injected i.p.

Experimental Legionnaires' disease in SCID-Beige mice reconstituted with human leucocytes.

A new small animal model of experimental Legionnaires' disease is described in which the reconstitution of SCID-Beige mice with human peripheral blood leucocytes permits the in-vivo growth of Legionella pneumophila in the lungs of aerosol-challenged mice. Following infection, viable bacterial counts within the lungs of mice increased from 10(5) cfu/lung at the time of inoculation to a maximum of 10(10) cfu/lung by 48 h post-inoculation. Two types of disease were detected in the lungs of infected SCID-Beige mice.

Metabolic cooperation in oral microbial communities during growth on mucin.

Hog gastric mucin has been used as a model glycoprotein to determine the role of particular glycosidases produced by different oral bacteria in the development of stable, diverse microbial communities. The patterns of glycosidase and protease activity were determined in pure cultures of ten representative species of oral bacteria using synthetic substrates. A five-member mixed culture was established in a chemostat, comprising species with minimal glycosidase and protease activity, in which hog gastric mucin was the major carbon and energy source.

A high containment polymodal pilot-plant fermenter--design concepts.

A 225 dm3 pilot-plant bioreactor system has been designed and constructed that is suitable for biohazardous fermentations. The design enables operation at containment levels above the requirements of good industrial large-scale practice (GILSP) without secondary containment of the whole plant. The main biosafety features of the systems include the use of steam barriers on O-ring seals, supply lines and stirrer seals, multiple O-ring seals, piping of condensate lines and pressure relief systems to a 'kill tank', double filtration of inlet and off gases and a mobile isolation unit that allows localised containment of sample valve and probe entry ports.