Colony-stimulating factor-1 suppresses responses to CpG DNA and expression of toll-like receptor 9 but enhances responses to lipopolysaccharide in murine macrophages

During bacterial infections, the balance between resolution of infection and development of sepsis is dependent upon the macrophage response to bacterial products. We show that priming of murine bone marrow-derived macrophages (BMMs) with CSF-1 differentially regulates the response to two such stimuli, LPS and immunostimulatory (CpG) DNA. CSF-1 pretreatment enhanced IL-6, IL-12, and TNF-alpha production in response to LPS but suppressed the same response to CpG DNA. CSF-1 also regulated cytokine gene expression in response to CpG DNA and LPS; CpG DNA-induced IL-12 p40, IL-12 p35, and TNF-alpha mRNAs were all suppressed by CSF-1 pretreatment. CSF-1 pretreatment enhanced LPS-induced IL-12 p40 mRNA but not TNF-alpha and IL-12 p35 mRNAs, suggesting that part of the priming effect is posttranscriptional. CSF-1 pretreatment also suppressed CpG DNA-induced nuclear translocation of NF-kappaB and phosphorylation of the mitogen-activated protein kinases p38 and extracellular signal-related kinases-1/2 in BMMs, indicating that early events in CpG DNA signaling were regulated by CSF-1. Expression of Toll-like receptor (TLR)9, which is necessary for responses to CpG DNA, was markedly suppressed by CSF-1 in both BMMs and thioglycolate-elicited peritoneal macrophages. CSF-1 also down-regulated expression of TLR1, TLR2, and TLR6, but not the LPS receptor, TLR4, or TLR5. Hence, CSF-1 may regulate host responses to pathogens through modulation of TLR expression. Furthermore, these results suggest that CSF-1 and CSF-1R antagonists may enhance the efficacy of CpG DNA in vivo.

Donor pretreatment with progenipoietin-1 is superior to granulocyte colony-stimulating factor in preventing graft-versus-host disease after allogeneic stem cell transplantation

The granulocyte colony-stimulating factor (G-CSF) and Fit-3 receptor agonist progenipoietin-1 (ProGP-1) has potent effects on dendritic cell (DC) expansion and may be an alternative to G-CSF for the mobilization of stem cells for allogeneic stem cell transplantation (SCT). We studied the ability of stem cell grafts mobilized with this agent to induce graft-versus-host disease (GVHD) to minor and major histocompatibility antigens in the well-described B6 --> B6D2F1 SCT model. ProGP-1, G-CSIF, or control diluent was administered to donor B6 mice. ProGP-1 expanded all cell lineages in the spleen, and unseparated splenocytes from these animals produced large amounts of interleukin 10 (IL-10) and transforming growth factor beta (TGFbeta) whereas the expression of T-cell adhesion molecules was diminished. Transplantation survival was 0%, 50%, and 90% in recipients of control-, G-CSF-, and ProGP-1-treated allogeneic donor splenocytes, respectively (P < .0001). Donor pretreatment with ProGP-1 allowed a 4-fold escalation in T-cell dose over that possible with G-CSF. Donor CD4 T cells from allogeneic SCT recipients of ProGP-1 splenocytes demonstrated an anergic response to host antigen, and cytokine production (interferon gamma [IFNγ], IL-4, and IL-10) was also reduced while CD8 T-cell cytotoxicity to host antigens remained intact. Neither CD11c(hi) DCs nor CD11c(dim)/B220(hi) DCs from ProGP-1-treated animals conferred protection from GVHD when added to control spleen. Conversely, when equal numbers of purified T cells from control-, G-CSF-, or ProGP-1-treated allogeneic donors were added to allogeneic T-cell-depleted control spleen, survival at day 60 was 0%, 15%, and 90%, respectively (P < .0001). The improved survival in recipients of ProGP-1 T cells was associated with reductions in systemic tumor necrosis factor alpha generation and GVHD of the gastrointestinal tract. We conclude that donor pretreatment with ProGP-1 is superior to G-CSIF for the prevention of GVHD after allogeneic SCT, primarily due to incremental affects on T-cell phenotype and function

HIV heterogeneity and proximity of homestead to roads in rural South Africa: an exploration using a geographical information system

OBJECTIVE To describe heterogeneity of HIV prevalence among pregnant women in Hlabisa health district, South Africa and to correlate this with proximity of homestead to roads. METHODS HIV prevalence measured through anonymous surveillance among pregnant women and stratified by local village clinic. Polygons were created around each clinic, assuming women attend the clinic nearest their home. A geographical information system (GIS) calculated the mean distance from homesteads in each clinic catchment to nearest primary (1 degrees) and to nearest primary or secondary (2 degrees) road. RESULTS We found marked HIV heterogeneity by clinic catchment (range 19-31% (P < 0.001). A polygon plot demonstrated lower HIV prevalence in catchments remote from 1 degrees roads. Mean distance from homesteads to nearest 1 degrees or 2 degrees road varied by clinic catchment from 1623 to 7569 m. The mean distance from homesteads to a 1 degrees or 2 degrees road for each clinic catchment was strongly correlated with HIV prevalence (r = 0.66; P = 0.002). CONCLUSIONS The substantial HIV heterogeneity in this district is closely correlated with proximity to a 1 degrees or 2 degrees road. GIS is a powerful tool to demonstrate and to start to analyse this observation. Further research is needed to better understand this relationship both at ecological and individual levels, and to develop interventions to reduce the spread of HIV infection.

When the going gets rough: effect of maternal size manipulation on larval quality

Variation in larval size has been shown to be an important factor for the post-metamorphic performance of marine invertebrates but, despite its importance, few sources of this variation have been identified. For a range of taxa, offspring size is positively correlated with maternal size but the reasons for this correlation remain unclear. We halved the size of colonies in the bryozoan Bugula neritina 1 wk prior to reproduction (but during embryogenesis) to determine if larval size is a fixed or plastic trait. We manipulated colonies in such a way that the ratio of feeding zooids to reproductive zooids was constant between treatment and control colonies. We found that manipulating colony size strongly affects larval size; halved colonies produced larvae that were similar to13% smaller than those produced by intact colonies. We entered these data into a simple model based on previous work to estimate the likely post-metamorphic consequences of this reduction in larval size. The model predicted that larvae that came from manipulated colonies would suffer similar to300% higher post-metamorphic mortality and similar to50% lower fecundity as adults. Colonies that are faced with a stress appear to be trading off current offspring fitness to maximize their own long-term fitness and this may explain previous observations of compensatory growth in colonial organisms. This study demonstrates that larval size is a surprisingly dynamic trait and strong links exist between the maternal phenotype and the fitness of the offspring. The performance of settling larvae may be determined not only by their larval experience but also by the experience of their mothers.

Localization of the Epstein-Barr virus protein LMP 1 to exosomes

The Epstein-Barr virus latent membrane protein (LMP 1) functions as a constitutively active signalling molecule and associates in lipid rafts clustered with other signalling molecules. Using immunofluorescent confocal microscopy, LMP 1 was shown to have an heterogeneous distribution among individual cells which was not related to the cell cycle stage. LMP 1 was shown to localize to intracellular compartments in cells other than the plasma membrane, Co-labelling of cells with both an LIMP 1 antibody and an antibody to the Golgi protein GS15 revealed that the intracellular LMP 1 partly co-localized with the Golgi apparatus. Further confirmation of intracellular LMP 1 localization was obtained by immunoelectron microscopy with rabbit polyclonal LIMP 1 antibodies and cryosectioning. As well as being present in intracellular foci, LMP 1 co-localized in part with MHC-II and was present on exosomes derived from a lymphoblastoid cell line. Preparations of LMP 1 containing exosomes were shown to inhibit the proliferation of peripheral blood mononuclear cells, suggesting that LIMP 1 could be involved in immune regulation. This may be of particular relevance in EBV-associated tumours such as nasopharyngeal carcinoma and Hodgkin's disease, as LMP 1-containing exosomes may be taken up by infiltrating T-lymphocytes, where LMP 1 could exert an anti-proliferative effect, allowing the tumour cells to evade the immune system.

Disulfide bond mutagenesis and the structure and function of the head-to-tail macrocyclic trypsin inhibitor SFTI-1

SFTI-1 is a novel 14 amino acid peptide comprised of a circular backbone constrained by three proline residues, a hydrogen-bond network, and a single disulfide bond. It is the smallest and most potent known Bowman-Birk trypsin inhibitor and the only one with a cyclic peptidic backbone. The solution structure of [ABA(3,11)]SFTI-1, a disulfide-deficient analogue of SFTI-1, has been determined by H-1 NMR spectroscopy. The lowest energy structures of native SFTI-1 and [ABA(3,11)]SFTI-1 are similar and superimpose with a root-mean-square deviation over the backbone and heavy atoms of 0.26 +/- 0.09 and 1.10 +/- 0.22 Angstrom, respectively. The disulfide bridge in SFTI-1 was found to be a minor determinant for the overall structure, but its removal resulted in a slightly weakened hydrogen-bonding network. To further investigate the role of the disulfide bridge, NMR chemical shifts for the backbone H-alpha protons of two disulfide-deficient linear analogues of SFTI-1, [ABA(3,11)]SFTI-1[6,5] and [ABA(3,11)]SFTI-1[1,14] were measured. These correspond to analogues of the cleavage product of SFTI-1 and a putative biosynthetic precursor, respectively. In contrast with the cyclic peptide, it was found that the disulfide bridge is essential for maintaining the structure of these open-chain analogues. Overall, the hydrogen-bond network appears to be a crucial determinant of the structure of SFTI-1 analogues.

Contribution of the collagen I alpha 1 and vitamin D receptor genes to the risk of hip fracture in elderly women

Context and Objective: Hip fracture is partially genetically determined. The present study was designed to examine the contributions of vitamin D receptor (VDR) and collagen I alpha 1 (COLIA1) genotypes to the liability to hip fracture in postmenopausal women. Design: The study was designed as a prospective population-based cohort investigation. Subjects: Six hundred seventy-seven postmenopausal women of Caucasian background, aged 70 +/- 7 yr (mean +/- SD), have been followed for up to 14 yr. Sixty-nine women had sustained a hip fracture during the period. Main Outcome: Atraumatic hip fractures were prospectively identified through radiologists' reports. Bone mineral density (BMD) at the hip and lumbar spine was measured by dual-energy x-ray absorptiometry. Genotypes: The TaqI and SpI COLIA1 polymorphisms of the VDR and COLIA1 genes were determined. Using the Single Nucleotide Polymorphism database, VDR TT, Tt, and tt genotypes were coded as TT, TC, and CC, whereas COLIA1 SS, Ss, and ss were coded as GG, GT, and TT. Results: Women with VDR CC genotype (16% prevalence) and COLIA1 TT genotype (5% prevalence) had an increased risk of hip fracture [odds ratio (OR) associated with CC, 2.6; 95% confidence interval (CI), 1.2-5.3; OR associated with TT, 3.8; 95% CI, 1.3-10.8] after adjustment for femoral neck BMD (OR, 3.4 per SD; 95% CI, 2.3-5.0) and age (OR, 1.4 per 5 yr; 95% CI, 1.1-1.7). Approximately 20 and 12% of the liability to hip fracture was attributable to the presence of the CC genotype and TT genotype, respectively. Conclusion: The VDR CC genotype and COLIA1 TT genotype were associated with increased hip fracture risk in Caucasian women, and this association was independent of BMD and age.