Characteristics of Beet Soilborne Mosaic Virus, a Furo-like Virus Infecting Sugar Beet

Beet soilborne mosaic virus (BSBMV) is a rigid rod-shaped virus transmitted by Polymyxa betae. Particles were 19 nm wide and ranged from 50 to over 400 nm, but no consistent modal lengths could be determined. Nucleic acids extracted from virions were polyadenylated and typically separated into three or four discrete bands of variable size by agarose-formaldehyde gel electrophoresis. RNA 1 and 2, the largest of the RNAs, consistently averaged 6.7 and 4.6 kb, respectively. The sizes and number of smaller RNA species were variable. The molecular mass of the capsid protein of BSBMV was estimated to be 22.5 kDa. In Northern blots, probes specific to the 3´ end of individual beet necrotic yellow vein virus (BNYVV) RNAs 1–4 hybridized strongly with the corresponding BNYVV RNA species and weakly with BSBMV RNAs 1, 2, and 4. Probes specific to the 5´ end of BNYVV RNAs 1–4 hybridized with BNYVV but not with BSBMV. No cross-reaction between BNYVV and BSBMV was detected in Western blots. In greenhouse studies, root weights of BSBMV-infected plants were significantly lower than mock-inoculated controls but greater than root weights from plants infected with BNYVV. Results of serological, hybridization, and virulence experiments indicate that BSBMV is distinct from BNYVV. However, host range, capsid size, and the number, size, and polyadenylation of its RNAs indicate that BSBMV more closely resembles BNYVV than it does other members of the genus Furovirus

Tracking dendritic cells in vivo

The reasons why certain vaccine adjuvants and/or delivery systems are more or less effective at inducing immune responses or promoting the preferential induction of particular types of response are unknown. While vaccine antigen discovery has benefited from a systematic approach, our limited understanding of the interactions of adjuvants with cells of the immune system has hampered rational adjuvant discovery and handicapped the development of new and more effective vaccines. It is well accepted that the component parts of the immune system do not work in isolation and their interactions occur in distinct and specialised micro- and macro-anatomical locations. Consequently, significant obstacles to the systematic investigation of adjuvant effects have been the complexity of the physiological environments that adjuvants interact with and the difficulty in directly investigating these interactions dynamically in vivo. Here we describe some of the immunological and microscopical techniques that have enabled the analysis of the immune cells and their interactions, in vivo, in real time. It is only by performing such detailed and fundamental studies in vivo that we can fully understand the cellular and molecular interactions that control the immune response. These types of systematic analyses of the events involved in adjuvant action are a prerequisite if we are truly to design, build and target vaccines effectively

The vaginal microbiota of guinea pigs

The vaginae of four guinea pigs were swabbed and samples cultured aerobically on horse blood agar, in 5 per cent carbon dioxide on MRS agar or anaerobically on anaerobic horse blood agar. Vaginal microbiota consisted almost exclusively of gram-positive bacteria including Corynebacterium, Streptococcus, Enterococcus, Staphylococcus and Lactobacillus species

The vaginal microbiota of guinea pigs

The vaginae of four guinea pigs were swabbed and samples cultured aerobically on horse blood agar, in 5 per cent carbon dioxide on MRS agar or anaerobically on anaerobic horse blood agar. Vaginal microbiota consisted almost exclusively of gram-positive bacteria including Corynebacterium, Streptococcus, Enterococcus, Staphylococcus and Lactobacillus species

Genetic modification of a vaginal strain of Lactobacillus fermentum and its maintenance within the reproductive tract after intravaginal administration

Many micro-organisms cause important diseases of the female genital tract. Because systematic vaccination does not usually provide a good immune response at mucosal sites, commensal lactobacilli from the female genital tract were developed as vehicles to deliver continued doses of foreign antigen directly to the genital mucosal surface with the aim of stimulating strong local mucosal immune responses. Lactobacilli were shown to be common inhabitants of the genital tract of the animal model studied, the guinea-pig. One species, Lactobacillus fermentum, was found in all guinea-pigs studied and was chosen for genetic manipulation. Improved methods of electroporation were developed to enable the routine transformation of L. fermentum BR11 strain with the broad host range plasmid pNZ17. This recombinantly modified Lactobacillus strain was shown to possess good segregational stability over 120 generations in the absence of antibiotic selection. When this recombinant L. fermentum strain was administered to the vaginal tract of three guinea-pigs it persisted for only 5 days. Despite the relatively short period of persistence in these initial experiments, this novel vaccine approach could provide an effective means of stimulating mucosal immunity in the female genital tract

Dissecting the components of the humoral immune response elicited by DNA vaccines

Although DNA vaccines appear to be efficient at inducing strong cellular immune responses, a number of questions remain regarding their ability to induce humoral immunity. The essential components for generating an antibody response include B and T cell recognition of antigen, subsequent activation, clonal expansion of each lymphocyte type and migration of T cells into B cell follicles to provide help, all leading to germinal centre formation and antibody production. We have employed a double adoptive transfer system based on ovalbumin (OVA)-specific CD4+ DO11.10 T cells and hen egg lysozyme (HEL)-specific MD4 B cells to assess all of these parameters in the context of DNA vaccination in vivo. We find that vaccination with DNA constructs expressing an OVA–HEL gene fusion (encoding contiguous T and B cell epitopes) can induce T cell activation, clonal expansion and migration into B cell follicles accompanied by B cell activation, blastogenesis, expansion and antibody production. These findings show that DNA vaccination can induce all of the components required for humoral immunity and also provide a system for in depth analysis of factors that influence the development of antibody responses. Such strategies may facilitate the rational design of vaccines capable of inducing effective humoral immunity