Comparative safety study of three inactivated BTV-8 vaccines in sheep and cattle under field conditions.

After massive epidemics of bluetongue disease in 2006 and 2007, Germany has started a compulsory vaccination program against bluetongue virus serotype 8 (BTV-8). Since the available vaccines had not yet been registered and only limited data were available on their performance, a safety study was conducted with three different inactivated monovalent vaccines under consideration for use in Germany. A total of 1007 sheep and 893 cattle were vaccinated and subsequently compared with 638 control animals (324 sheep and 314 cattle). During the study, all animals remained in good health condition. After the initial immunisation, only local swellings were observed in a small number of animals. Following revaccination, several sheep developed more distinct local reactions and a temporary rise in body temperature. Severe systemic reactions were not detected in any of the study groups. Among cattle, neither fever, nor a decrease in milk production and only temporary low-grade local reactions were observed. Overall, our results demonstrate a high level of safety of all vaccines tested.

Monocyte enrichment from leukapharesis products for the generation of DCs by plastic adherence, or by positive or negative selection.

BACKGROUND: DCs for use in immunotherapy are frequently generated from peripheral blood monocytes. However, there are different approaches to monocyte enrichment. METHOD: Plastic adherence is a widely used method for the enrichment of monocytes collected in a leukapheresis procedure. Alternatively,monocytes may be enriched by positive selection using magnetic beads coupled to CD14 Abs, or by cell depletion using beads coupled to Abs against CD2 and CD19 to remove non-monocytes. RESULTS: Positive selection resulted in the highest purity of immature DCs (97 +/- 1%), but in a low yield (8 +/- 3%). In contrast, depletion of non-monocytes gave a good yield (21 +/- 6%), but insufficient purity (42 +/- 10%). Conventional adherence procedures resulted in a good yield (25 +/- 5%) and reasonable purity (72 +/- 4%). All three monocyte enrichment procedures resulted in DCs that underwent maturation upon exposure to a combination of lipopolysaccharide and IFN-gamma. These DCs had a typical immune phenotype, they released similar amounts of IL-12, and had the capacity to support MLR. CONCLUSION: Our data provide a basis to choose a monocyte enrichment procedure that favors high purity or a high yield. However, if a manual open system suffices, plastic adherence is a reasonable alternative.

Innate antimicrobial peptide protects the skin from invasive bacterial infection.

In mammals, several gene families encode peptides with antibacterial activity, such as the beta-defensins and cathelicidins. These peptides are expressed on epithelial surfaces and in neutrophils, and have been proposed to provide a first line of defence against infection by acting as 'natural antibiotics'. The protective effect of antimicrobial peptides is brought into question by observations that several of these peptides are easily inactivated and have diverse cellular effects that are distinct from antimicrobial activity demonstrated in vitro. To investigate the function of a specific antimicrobial peptide in a mouse model of cutaneous infection, we applied a combined mammalian and bacterial genetic approach to the cathelicidin antimicrobial gene family. The mature human (LL-37) and mouse (CRAMP) peptides are encoded by similar genes (CAMP and Cnlp, respectively), and have similar alpha-helical structures, spectra of antimicrobial activity and tissue distribution. Here we show that cathelicidins are an important native component of innate host defence in mice and provide protection against necrotic skin infection caused by Group A Streptococcus (GAS).

Processing site and gene structure for the murine antimicrobial peptide CRAMP.

Cathelicidins are a mammalian gene family notable for the presence of an antibiotic peptide encoded at the carboxy-terminal domain of the nascent pre-pro-protein. Following proteolytic release, this peptide has direct antimicrobial activity. To understand the function and regulation of cathelicidin we investigated the peptide processing site and gene structure of the mouse cathelicidin CRAMP. Amino acid sequencing of the purified native 5 kDa peptide identified the functionally critical amino terminal sequence of mature CRAMP. Characterization of the CRAMP gene (Cnlp) showed homology in structure and sequence identity in several potential transcription factors binding sites found in the human cathelicidin LL-37. Overall, CRAMP shows striking similarities with LL-37, making it a useful model for study of human cathelicidin function and regulation.

Farm and personal characteristics of the clientele of a community-based animal-health service programme in northern Malawi.

The social background, farm characteristics, indicators of income and self-evaluation returns of 96 randomly selected users of a Basic Animal Health Service (BAHS) programme in northern Malawi were compared with those of 96 matched past-users and 96 non-users, respectively. All 288 farms were visited between July and October 1997. Data analysis was performed using univariate and multivariate techniques. The results showed that, on average, BAHS users had larger cattle herds (16.3) than part-users (14.7) or non-users (12.4). Similarly, the annual yields of crops were higher for users compared to either of the other groups. Users occupied better houses and owned a larger number of farm and household items than did part-users or non-users. A third of all farmers were engaged in additional income generation to lessen the risk of poverty. However, analysis of the livestock management and the educational background of the farmers suggested that usage of the BAHS programme was not only determined by already existing 'wealth'. Improved livestock husbandry and management measures, which do not require capital investment, were more frequently applied by users compared to either of the other groups. Non-users and part-users had attained a lower level of education, were less open towards improved farming methods and felt less knowledgeable than BAHS users. The average straight-line distances from farms using BAHS to their respective village animal health worker (2.2 km) or veterinary assistant (2.9 km) were similar but varied according to ecological zone. Intensified extension and awareness meetings in villages will be required to get more non-users involved in BAHS.

Characteristics and performance of village animal health workers and veterinary assistants in northern Malawi.

Fourty-two village animal health workers called keymen (KM) and 84 veterinary assistants (VA) involved in a Basic Animal Health Service (BAHS) Programme in northern Malawi were interviewed during 1998. The general characteristics and perceptions of both groups were analysed using uni- and multivariate techniques. Detailed sales and treatment patterns of six KM and 12 VA were evaluated for the period September 1996 to August 1997. Results indicated an overall job-satisfaction for 82% of KM and 83 % of VA. Estimated weekly involvement in livestock service delivery, particularly of KM, was 3.7 days on average. Total annual drug sales of KM and VA between 1996 and 1997 on average were equivalent to US$ 124 and US$ 218 respectively. Most livestock remedies were issued for treatment of calves, followed by adult cattle, chickens and small ruminants. The changes suggested by VA and KM in order to improve field performance focused on regular refresher training by the BAHS programme.

Peptide localization and gene structure of cryptdin 4, a differentially expressed mouse paneth cell alpha-defensin.

Paneth cells in crypts of the small intestine express antimicrobial peptides, including alpha-defensins, termed cryptdins in mice. Of the known Paneth cell alpha-defensins, the cryptdin 4 gene is unique, because it is inactive in the duodenum and expressed at maximal levels in the distal small bowel (D. Darmoul and A. J. Ouellette, Am. J. Physiol. 271:G68-G74, 1996). With a cryptdin 4-specific antibody, immunohistochemical staining of ileal Paneth cells was strong and specific for cytoplasmic granules, demonstrating that this microbicidal peptide is a secretory product of Paneth cells in the distal small intestine. Consistent with the pattern of cryptdin 4 mRNA distribution along the length of the gut, the cryptdin 4 peptide was not detected in duodenum. Structurally, the cryptdin 4 gene resembles other Paneth cell alpha-defensin genes. Its two exons, transcriptional start site, intron, splice sites, and 3' flanking sequences are characteristic of the highly conserved mouse alpha-defensin genes. However, in the region upstream of the transcriptional initiation site, the cryptdin 4 gene contains a repeated 130-bp element that is unique to this alpha-defensin gene. Every independent cryptdin 4 genomic clone examined carries the repeated element, which contains putative recognition sequences for TF-IID-EIIA, cMyc-RS-1, and IgHC.2/CuE1.1; the repeat proximal to the start of transcription replaces DNA at the corresponding position in other mouse alpha-defensin genes. We speculate that this unique duplicated element may have a cis-acting regulatory role in the positional specificity of cryptdin 4 gene expression.

Comparison between a live and an inactivated vaccine against Newcastle disease in village chickens. A field study in northern Malawi.

A total of 156 chickens in two villages in Malawi were marked and sampled. One hundred and fifteen of these were vaccinated against Newcastle disease immediately after blood sampling, using the V4 heat-resistant strain applied by eye-drop in one village and the inactivated Newcavac vaccine in the other village. A second blood sample was collected 4 weeks after vaccination. The samples were examined using an indirect ELISA test kit. The titre group median ranged from 2 to 3 before vaccination. Both vaccines led to a positive immune response. Newcavac induced higher and more homogeneous titres compared with the V4 vaccine. There was also an increase in the median of the control group where V4 live vaccine had been applied. The differences between the median titres induced by V4, Newcavac and controls were statistically significant.

Differences in the concentrations of small, anionic, antimicrobial peptides in bronchoalveolar lavage fluid and in respiratory epithelia of patients with and without cystic fibrosis.

Affinity-purified rabbit polyclonal (PAB96-1) and mouse monoclonal (1G9-1C2) antibodies to synthetic H-DDDDDDD-OH, an antimicrobial anionic peptide (AP) originally isolated from ovine pulmonary surfactant, were prepared and used to assess the concentrations of AP-like molecules in human respiratory tract samples. In bronchoalveolar lavage fluids, concentrations of AP-like molecules measured by enzyme-linked immunosorbent assay were significantly lower in 13 patients with cystic fibrosis (CF) (mean +/- standard deviation [SD], 0.78 +/- 0.46 mM) than in 34 patients without CF (1. 30 +/- 0.66 mM) (P = 0.01). In pulmonary tissues of three patients without CF, very little antigen was stained in the apical cytoplasm of the bronchial and bronchiolar epithelium yet robust staining was seen in the alveolar epithelium. In pulmonary tissues of three patients with CF, robust staining of antigen was seen in the apical cytoplasm of the bronchial and bronchiolar epithelium yet no staining was seen in the alveolar epithelium. These results show that AP-like molecules are present in healthy human respiratory tract samples and differ in concentration and location of expression in patients with and without CF.

Antimicrobial peptides as mediators of epithelial host defense.

Mammalian epithelial surfaces are remarkable for their ability to provide critical physiologic functions in the face of frequent microbial challenges. The fact that these mucosal surfaces remain infection-free in the normal host suggests that highly effective mechanisms of host defense have evolved to protect these environmentally exposed tissues. Throughout the animal and plant kingdoms, endogenous genetically encoded antimicrobial peptides have been shown to be key elements in the response to epithelial compromise and microbial invasion. In mammals, a variety of such peptides have been identified, including the well-characterized defensins and cathelicidins. A major source of these host defense molecules is circulating phagocytic leukocytes. However, more recently, it has been shown that resident epithelial cells of the skin and respiratory, alimentary, and genitourinary tracts also synthesize and release antimicrobial peptides. Both in vitro and in vivo data support the hypothesis that these molecules are important contributors to intrinsic mucosal immunity. Alterations in their level of expression or biologic activity can predispose the organism to microbial infection. The regulatory and developmental aspects of antimicrobial peptide synthesis are discussed from a perspective that emphasizes the possible relevance to pediatric medicine.

Detection of anionic antimicrobial peptides in ovine bronchoalveolar lavage fluid and respiratory epithelium.

Three small antimicrobial anionic peptides (AP) were originally isolated from an ovine pulmonary surfactant. However, their presence in bronchoalveolar lavage (BAL) fluid and tissues of the respiratory tract is unknown. In this study, we made affinity-purified rabbit polyclonal and mouse monoclonal antibodies to synthetic H-DDDDDDD-OH. Antibody specificity was assessed by a competitive enzyme-linked immunosorbent assay (ELISA), and the exact epitope binding sites were determined with analog peptides synthesized on derivatized cellulose. These antibodies were used to detect AP in BAL fluid by ELISA and in respiratory tissues by Western blot analysis and immunocytochemistry. BAL fluid from 25 sheep contained 0.83 +/- 0.33 mM AP (mean +/- standard deviation; range, 0.10 to 1.59 mM) and was antimicrobial. The presence of AP in BAL fluid was confirmed by reverse-phase high-pressure liquid chromatography fractionation followed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry on those fractions which were positive by competitive ELISA and demonstrated antimicrobial activity. In Western blots, polyclonal antibody PAB96-1 and monoclonal antibody 1G9-1C2 (5.0 micrograms/ml) detected four bands in solubilized turbinate and tracheal epithelial cells (53.7, 31.2, 28.0, and 25.7 kDa) and five bands in lung homogenates (53.5, 37.1, 31.2, 28.0, and 25.7 kDa). Only a single band was seen in solubilized liver and small-intestine homogenates, and no bands were seen in blots containing BAL fluid, albumin, or kidney or spleen homogenates. In pulmonary-tissue sections, both antibodies PAB96-1 and 1G9-1C2 identified accumulated protein in the apical cytoplasm of the bronchial and bronchiolar epithelia, in the cytoplasm of pulmonary endothelial cells, and in an occasional alveolar macrophage. As a first step in identifying a candidate AP precursor gene(s), degenerate oligonucleotides representing all possible coding combinations for H-GADDDDD-OH and H-DDDDDDD-OH were synthesized and used to probe Southern blots of sheep genomic DNA. Following low-stringency washes and a 2-day exposure, strongly hybridizing bands could be identified. One degenerate oligonucleotide, SH87, was used as a hybridization probe to screen a sheep phage genomic library. Two independent phage contained the H-GADDDDD-OH coding sequence as part of a larger predicted protein. AP may originate as part of an intracellular precursor protein, with multistep processing leading to the release of the heptapeptide into mucosal secretions. There it may interact with other innate pulmonary defenses to prevent microbial infection.

Antimicrobial peptides: an emerging concept in cutaneous biology.

Antimicrobial peptides are part of the host defense systems of plants, insects, fish, amphibia, birds, and mammals. These small proteins were previously thought of as an evolutionarily ancient system of immune protection with little relevance to the normal function of human skin. Recent developments have found that mammalian skin expresses these gene-encoded peptide antibiotics during inflammatory events such as wound repair, contact dermatitis, and psoriasis. The presence of these peptides in the skin forms a barrier for innate host protection against microbial pathogenesis. Furthermore, antimicrobial peptides also act on animal cells by stimulating them to change behaviors such as syndecan expression, chemotaxis, and chloride secretion. The combination of effects on host cells with antimicrobial action in a single molecule represents an efficient defense and response system against injury. Understanding the action of antimicrobial peptides in skin may yield further insight into the mechanism of innate cutaneous disease control and provide new approaches to therapy of wounds and inflammatory dermatitis.

Antimicrobial peptide expression is developmentally regulated in the ovine gastrointestinal tract.

Antimicrobial peptides are abundant components of the innate immune system present in species throughout the plant and animal kingdoms. In mammals, these immune peptides have been localized to epithelial tissues of the pig, mouse, rat, cow and human gastrointestinal tracts. We have identified in sheep two members of the beta-defensin antimicrobial peptide gene family that are expressed in a unique pattern throughout the gastrointestinal tract. Sheep beta-defensin 1 mRNA is the most prevalent from tongue to colon with the exception of the distal ileum, where beta-defensin 2 mRNA predominates. Sheep beta-defensin expression varies significantly between animals and is developmentally regulated both pre- and postnatally. These changes in antimicrobial peptide expression may correlate with anatomical differentiation as well as physiologic adaptations to extra-uterine life.

Localization and genomic organization of sheep antimicrobial peptide genes.

Antimicrobial peptides are an abundant and diverse component of animal innate immunity. Within mammalian species, defensins and cathelicidins are the two principal antimicrobial peptide families. We identified and sequenced ten new sheep genes which encode potential antimicrobial peptides including two beta-defensins and eight cathelicidins. We mapped the two-exon beta-defensin genes to sheep chromosome 26 and the four-exon cathelicidin genes to sheep chromosome 19 using sheep-hamster somatic cell hybrids in conjunction with flow-sorted sheep chromosomes. These assignments confirm homology between sheep, cattle, mouse, and human antimicrobial peptide gene families. Contig construction for the sheep cathelicidin gene family demonstrates that three genes, OaDodeA, OaDodeB, and OaMAP-34, are present head-to-tail in a 14.5 kb region, and that four proline/arginine-rich genes, OaBac5, OaBac7.5, OaBac11, and OaBac6, are arranged head-to-tail in a region covering 30.5 kb. This richly diverse family of sheep cathelicidin peptides is encoded in a gene array which may reflect the mechanism of its evolution.

The mouse genome encodes a single homolog of the antimicrobial peptide human beta-defensin 1.

The cysteine-rich beta-defensin peptides are broad-spectrum bactericidal agents expressed in epithelial and myeloid tissues. The human beta-defensin-1 (hBD-1) gene maps adjacent to the human alpha-defensin cluster and is expressed in the respiratory, gastrointestinal and genitourinary tracts. Here, we characterize a mouse beta-defensin gene (mBD-1) which is: (1) closely related to hBD-1 both in sequence and gene organization; (2) expressed at high levels in the mouse kidney and at lower levels in brain, heart, lung, uterus, spleen, skeletal muscle, stomach, and small intestine; and (3) maps to mouse chromosome 8 at or near the location of the mouse alpha-defensin genes. These data indicate that mBD-1 is a close homolog of hBD-1, and suggest that analysis of its role in mouse host defense may provide significant insights into human epithelial innate immunity.

Small, anionic, and charge-neutralizing propeptide fragments of zymogens are antimicrobial.

Some inactive precursor proteins, or zymogens, contain small, amino terminus, homopolymeric regions of Asp that neutralize the cationic charge of the active protein during synthesis. After posttranslational cleavage, the anionic propeptide fragment may exhibit antimicrobial activity. To demonstrate this, ovine trypsinogen activation peptide, and frog (Xenopus laevis) PYL activation peptide, both containing homopolymeric regions of Asp, were synthesized and tested against previously described surfactant-associated anionic peptide. Peptides inhibited the growth of both gram-negative (MIC, 0.08 to 3.00 mM) and gram-positive (MIC, 0.94 to 2.67 mM) bacteria. Small, anionic, and charge-neutralizing propeptide fragments of zymogens form a new class of host-derived antimicrobial peptides important in innate defense.

Molecular analysis of the sheep cathelin family reveals a novel antimicrobial peptide.

Cathelin-related genes are characterized by the presence of a prepro sequence which is highly conserved both within and between species. 3' RACE analysis on sheep bone marrow RNA, using a primer based on a conserved cathelin family coding region, demonstrated the presence of at least three ovine cathelin-related cDNAs. One of these encodes a novel prepropeptide with a predicted C-terminal cleavage product RGLRRLGRKIAHG-VKKYGPTVLRIIRIAG. The chemically synthesized form of this 29 amino acid peptide is shown to be a thermostable, broad spectrum, bactericidal agent.

Mouse Paneth cell defensins: primary structures and antibacterial activities of numerous cryptdin isoforms.

Cryptdins are antimicrobial peptides of the defensin family that are produced by intestinal Paneth cells. mRNAs encoding 17 cryptdin isoforms have been characterized from a cDNA library generated from a single jejunal crypt. Six cryptdin cDNAs correspond to known peptides, and the remainder predict 11 novel Paneth cell defensins. Most cryptdin cDNAs have > or = 93% nucleotide sequence identity overall, except for cryptdin 4 and 5 cDNAs, whose respective mature peptide-encoding regions are only 74 and 78% identical to that of cryptdin 1. Cryptdin cDNAs differ at a small number of nucleotide positions: frequent substitutions were found in codons 38 and 52 of the propiece and in codons 68, 73, 76, 87, and 89 of the deduced peptides; cDNA clones with changes in codons 74, 83, and 88 were found, but there were fewer of these. The antimicrobial activities of cryptdins 1 to 6 were tested against Escherichia coli ML35 in two assays. In an agar diffusion assay, the potencies of cryptdins 1 to 3, 5, and 6 were approximately equivalent to that of rabbit neutrophil defensin NP-1 but cryptdin 4 was 30 times more active than NP-1. In a bactericidal assay system, cryptdins 1 and 3 to 6 were equally active at 10 micrograms/ml but cryptdin 2 and rabbit NP-1 were not active at this concentration. Since cryptdins 2 and 3 differ only at residue 10 (Thr and Lys, respectively), this amino acid appears to function in bactericidal interaction with E. coli. The demonstration that Paneth cells express a diverse population of microbicidal defensins further implicates cryptdins in restricting colonization or invasion of small intestinal epithelium by bacteria.

A family of defensin-like genes codes for diverse cysteine-rich peptides in mouse Paneth cells.

Cryptdins constitute a diverse population of defensins in Paneth cells of intestinal crypts. In mice, certain intestinal mRNAs, termed "CRSIC" and "CRS4C," are considered to be cryptdin-related sequences, because their prepro-coding sequences are 94% identical to those of cryptdin-1 mRNA; however, their predicted products, which are cationic, cysteine-rich peptides are not defensins (A. J. Ouellette and J. C. Lualdi, J. Biol. Chem. 265: 9831-9837, 1990). Here we describe several mouse small intestinal mRNAs and genes that code for CRS4C prepropeptides. The 10-kDa deduced CRS4C proteins consist of a prepro sequence, potential monobasic or dibasic peptide cleavage sites, a predicted 3.7-kDa peptide that contains 7 [C]-[X]-[Y] repeats, and a C(N/K)CNPK carboxyl-terminal consensus sequence. In situ hybridization experiments showed that CRS4C mRNAs are found in Paneth cells of adult small bowel. The CRS4C genes closely resemble cryptdin genes, having a two-exon structure with highly conserved transcription start sites, intron-exon junctions, and a single intron of approximately 550 bp. Like the cryptdin genes, exon 1 of CRS4C genes consists of 5' untranslated sequences (UTS) and the prepro-coding region, and exon 2 codes for the predicted mature peptide and 3' UTS. Despite the similarity of first exons in CRS4C and cryptdin genes, their introns exhibit very little homology, and their second exons code for unrelated peptides. Analysis of introns suggests that the ancestral cryptdin and CRS4C genes may have diverged from a common ancestor in the distant past and expanded only recently. We speculate that the cryptdin/CRS genes evolved so that prepro regions encoded by exon 1 were conserved to allow the varied peptides coded by exon 2 to be directed into Paneth cell secretory granules.

Paneth cell differentiation in the developing intestine of normal and transgenic mice.

Paneth cells represent one of the four major epithelial lineages in the mouse small intestine. It is the only lineage that migrates downward from the stem-cell zone located in the lower portion of the crypt of Lieberkühn to the crypt base. Mature Paneth cells release growth factors, digestive enzymes, and antimicrobial peptides from their apical secretory granules. Some of these factors may affect the crypt stem cell, its transit-cell descendants, differentiating villus-associated epithelial lineages, and/or the gut microflora. We used single and multilabel immunocytochemical methods to study Paneth cell differentiation during and after completion of gut morphogenesis in normal, gnotobiotic, and transgenic mice as well as in intestinal isografts. This lineage emerges coincident with cytodifferentiation of the fetal small intestinal endoderm, formation of crypts from an intervillus epithelium, and establishment of a stem-cell hierarchy. The initial differentiation program involves sequential expression of cryptdins, a phospholipase A2 (enhancing factor), and lysozyme. A dramatic increase in Paneth cell number per crypt occurs during postnatal days 14-28, when crypts proliferate by fission. Accumulation of fucosylated and sialylated glycoconjugates during this period represents the final evolution of the lineage's differentiation program. Establishment of this lineage is not dependent upon instructive interactions from the microflora. Transgenic mice containing nucleotides -6500 to +34 of the Paneth cell-specific mouse cryptdin 2 gene linked to the human growth hormone gene beginning at its nucleotide +3 inappropriately express human growth hormone in a large population of proliferating and nonproliferating cells in the intervillus epithelium up to postnatal day 5. Transgene expression subsequently becomes restricted to the Paneth cell lineage in the developing crypt. Cryptdin 2 nucleotides -6500 to +34 should be a useful marker of crypt morphogenesis and a valuable tool for conducting gain-of-function or loss-of-function experiments in Paneth cells.