Cellular vaccine therapy for cancer

Observations that cells of the immune system are able to kill tumor cells both in vitro and in animal models have provided a compelling rationale for pursuit of a strategy whereby immune cells are administered as a therapeutic vaccine to patients with cancer. The successful outcome of this approach depends upon the ability to deliver this therapy in a manner in which a potent immune response is elicited. By harnessing the capacity of dendritic cells that are pivotal in priming the immune response and using gene therapy approaches to optimise the immune response, this may ultimately prove efficacious in the management of human cancer. Promising reports from recent clinical trials suggest that this may well be a realistic goal.     

In Vivo Complementation of ureB Restores the Ability of Helicobacter pylori To Colonize

The objective of this study was to determine (i) if complementation of ureB-negative Helicobacter pylori restores colonization and (ii) if urease is a useful reporter for promoter activity in vivo. Strains used were M6, M6DeltaureB, and 10 recombinant derivatives of M6 or M6DeltaureB in which urease expression was under the control of different H. pylori promoters. Mice were orally inoculated with either the wild type or one of the mutant strains, and colonization, in vivo urease activity, and extent of gastritis were determined. Of eight M6DeltaureB recombinants tested, four colonized mice. Of those, three had the highest in vitro urease activity of any of the recombinants, significantly different from that of the noncolonizing mutants. The fourth colonizing recombinant, with ureB under control of the cag-15 promoter, had in vitro urease activity which did not differ significantly from the noncolonizing strains. In vivo, urease activities of the four colonizing transformants and the wild-type control were indistinguishable. There were no differences in gastritis or epithelial lesions between mice infected with M6 and those infected with the transformants. These results demonstrate that recovery of urease activity can restore colonizing ability to urease-negative H. pylori. They also suggest that cag-15 is upregulated in vivo, as was previously suggested by demonstrating that it is upregulated upon contact with epithelial cells. Finally, our results suggest that total urease activity and colonization density do not contribute to gastritis due to H. pylori.     

Lung dendritic cells are primed by inhaled particulate antigens, and retain MHC class II/antigenic peptide complexes in hilar lymph nodes for a prolonged period of time

Intratracheal (IT) administration of heat-killed Listeria monocytogenes (HKL) results in an influx of macrophage and dendritic cell (DC) precursors into the lung interstitium. Low-density, FcR+, interstitial lung cells isolated from rats instilled 24 hr before with HKL or vehicle alone, were > 90% Mar1+. After culturing with granulocyte-macrophage colony-stimulating factor (GM-CSF) for 3 days, up to 24% of the loosely adherent cells were DC that stimulated allogeneic T-cell proliferation in an mixed lymphocyte reaction (MLR) assay. After only an overnight incubation with GM-CSF, however, the capacity of interstitial Mar1+ cells to stimulate HKL immune T-cell proliferation without exogenous antigen was low. By contrast, when DC were isolated as major histocompatibility complex (MHC) class II+ cells from rat lungs at 1, 3, 7 and 14 days after HKL instillation and cultured overnight with GM-CSF, their antigen presentation capacity without added exogenous antigen was robust, but declined over the 2-week period. Interestingly, hilar lymph node DC maintained their HKL antigen-presenting capacity for up to 2 weeks after instillation of HKL. Following IT administration of PKH-26 labelled HKL, fluorescent or immunolabelled organisms were detected in OX62+ DC in airway epithelium, lung interstitium and hilar lymph nodes in situ and in MHC class II+ DC isolated from these sites. We conclude that newly immigrated Mar1+ lung DC precursors, while efficient in endocytosing particulate antigens, are incapable of eliciting a significant proliferative response from HKL-sensitized T cells. By contrast, MHC class II+ DC isolated from lungs and incubated overnight with GM-CSF induce vigorous antigen-specific T-cell proliferation. Antigen-loaded lung DC in hilar lymph nodes maintain their antigen presentation capacity for up to 2 weeks.     

Results of unrelated cord blood transplant in fanconi anemia patients: risk factor analysis for engraftment and survival.

We retrospectively analyzed results of unrelated cord blood transplantation (UCBT) in 93 Fanconi anemia (FA) patients. Median age at transplantation was 8.6 years (1-45). The units transplanted were HLA-A, -B, or -DRB1 identical in 12 cases, 1 HLA mismatch in 35 cases, and 2 or 3 HLA differences in 45 cases. The median number of nucleated cells (NC) and CD34+ cells infused of recipient weight was 4.9x10(7)/kg and 1.9x10(5)/kg, respectively. Participating centers selected the preparative regimen of their choice, in 57 patients (61%), it included Fludarabine. Graft-versus-host disease (GVHD) prophylaxis consisted mostly of cyclosporine with prednisone. Cumulative incidence (CI) of neutrophil recovery was 60+/-5% at day +60. In multivariate analysis, Fludarabine containing regimen and NC infused>or=4.9x10(7)/kg were associated with higher probability of recovery. CI of grade II-IV acute and of chronic GVHD (aGVHD, cGVHD) was 32%+/-5% and 16%+/-4%, respectively. Overall survival (OS) was 40%+/-5%. In multivariate analysis, factors associated with favorable outcome were use of Fludarabine in the conditioning regimen, number of NC infused>or=4.9x10(7)/kg, and negative cytomegalovirus (CMV) serology in the recipient. In conclusion, factors easily modifiable such as donor selection and a Fludarabine-containing regimen can considerably improve survival in FA patients given a UCBT. These data are the basis for designing prospective protocols.     

Persistent rat cytomegalovirus (RCMV) infection of the salivary glands contributes to the anti-RCMV humoral immune response

The salivary glands are the major sites of persistent replication of rat cytomegalovirus (RCMV). At several months post infection (pi), infectious RCMV is usually still produced in the salivary glands but not in any other organ or tissue of the rat. To investigate whether the persistence of RCMV in the salivary glands is crucial to the pathogenesis of viral infection, we monitored the progression of RCMV-induced disease in rats from which the salivary glands had been surgically removed (desalivated) as well as in sham-operated rats, both after a lethal and sublethal challenge with RCMV. Desalivation did not have a significant effect on either RCMV-induced morbidity or mortality. As expected, at 1 year pi, relatively high levels of infectious virus were detected in the salivary glands of sham-operated rats, whereas neither infectious virus nor RCMV DNA could be detected in liver, spleen and lungs of these animals. Infectious virus and viral DNA were also undetectable in organs from desalivated animals at 1 year pi. Surprisingly, a difference was found between desalivated and sham-operated rats in the titers of anti-RCMV IgG antibodies, which were significantly higher in sham-operated rats than in desalivated animals at 183, 295 and 365 days pi. This finding indicates that the persistence of RCMV in the salivary glands may contribute significantly to the anti-RCMV humoral immunity of infected rats.     

Intracellular mechanisms governing the acute phase of β-endorphin secretion from the corticotrope in vitro

It is not certain which protein kinase (A, C or both) is involved in the acute phase of β-endorphin (β-EP) release stimulated in the corticotrope by vasopressin (VP) and corticotropin-releasing factor (CRF). We have employed an isolated ovine anterior pituitary cell superfusion system to determine the dynamic effects of forskolin, a protein kinase A (PKA) stimulator, and phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator. Both secretagogues stimulated β-EP release within 5 min and therefore both PKA and PKC are potential mediators of the acute phase of hormonal stimulation of the corticotrope. Pretreatment with PMA specifically desensitized the pituitary cell columns to subsequent PMA exposure while not significantly altering sensitivity to forskolin or 50 mM KCl.     

A member of a conserved Plasmodium protein family with membrane-attack complex/perforin (MACPF)-like domains localizes to the micronemes of sporozoites

Pore-forming proteins are employed by many pathogens to achieve successful host colonization. Intracellular pathogens use pore-forming proteins to invade host cells, survive within and productively interact with host cells, and finally egress from host cells to infect new ones. The malaria-causing parasites of the genus Plasmodium evolved a number of life cycle stages that enter and replicate in distinct cell types within the mosquito vector and vertebrate host. Despite the fact that interaction with host-cell membranes is a central theme in the Plasmodium life cycle, little is known about parasite proteins that mediate such interactions. We identified a family of five related genes in the genome of the rodent malaria parasite Plasmodium yoelii encoding secreted proteins all bearing a single membrane-attack complex/perforin (MACPF)-like domain. Each protein is highly conserved among Plasmodium species. Gene expression analysis in P. yoelii and the human malaria parasite Plasmodium falciparum indicated that the family is not expressed in the parasites blood stages. However, one of the genes was significantly expressed in P. yoelii sporozoites, the stage transmitted by mosquito bite. The protein localized to the micronemes of sporozoites, organelles of the secretory invasion apparatus intimately involved in host-cell infection. MACPF-like proteins may play important roles in parasite interactions with the mosquito vector and transmission to the vertebrate host.     

Genomic instability occurs in colorectal carcinomas but not in adenomas

Genomic instability, as demonstrated by the presence of additional alleles at short tandemly repeated (STR) loci, has recently been observed in colorectal tumours from individuals with hereditary non-polyposis colorectal cancer (HNPCC), and in some sporadic tumours. These neoplasms have been called replication error positive (RER⁺). In this study, we confirm the presence of genomic instability in a proportion of unselected colorectal carcinomas but find no evidence of instability in adenomas. We further report replication errors in a tetranucleotide sequence, and in STRs within two tumour suppressor genes. 108 colorectal adenocarcinomas and 46 adenomas were analysed for the presence of variant bands at 4–15 microsatellite markers. Seven (6.5%) of carcinomas were RER⁺, four of which originated from the proximal colon. Analysis of the adenomas and of matched adenoma-carcinoma and carcinoma-metastatic samples from four patients suggests that the replication errors may occur during the development of carcinomas but are rare in adenomas. © 1993 Wiley-Liss, Inc.     

Association between Fruit and Vegetable Intakes and Mental Health in the Australian Diabetes Obesity and Lifestyle Cohort

Increasing prevalence of mental health disorders within the Australian population is a serious public health issue. Adequate intake of fruits and vegetables (FV), dietary fibre (DF) and resistant starch (RS) is associated with better mental and physical health. Few longitudinal studies exist exploring the temporal relationship. Using a validated food frequency questionnaire, we examined baseline FV intakes of 5845 Australian adults from the AusDiab study and estimated food group-derived DF and RS using data from the literature. Perceived mental health was assessed at baseline and 5 year follow up using SF-36 mental component summary scores (MCS). We conducted baseline cross-sectional analysis and prospective analysis of baseline dietary intake with perceived mental health at 5 years. Higher baseline FV and FV-derived DF and RS intakes were associated with better 5 year MCS (p < 0.001). A higher FV intake (754 g/d vs. 251 g/d, Q4 vs. Q1) at baseline had 41% lower odds (OR = 0.59: 95% CI 0.46–0.75) of MCS below population average (<47) at 5 year follow up. Findings were similar for FV-derived DF and RS. An inverse association was observed with discretionary food-derived DF and RS. This demonstrates the association between higher intakes of FV and FV-derived DF and RS with better 5 year mental health outcomes. Further RCTs are necessary to understand mechanisms that underlie this association including elucidation of causal effects.