Establishment of a pure culture of distinct cell types from bovine placental cotyledon

Methods are described to establish distinct cell cultures from bovine placental cotyledon. The villous tissue of the bovine placental cotyledon is collected and dissociated with 0.125% trypsin. The cells are then cultured in three different media: a serum-free medium, a growth factor supplemented medium, and a medium with 10% serum. A polygonal cell line grew out of the serum-containing medium, a fan-shaped cell line grew out of the serum-free medium, and an epitheloid cell line grew out of the growth factor supplemented medium. These cells maintained their morphology when grown in serum containing medium. The preference of distinct cells for different media in vitro reflects the in vivo physiological regulation of these cells. These distinct cultures re ideal to study the extrinsic and interactive factors in bovine placenta.

Infection of mice with the agent of human granulocytic ehrlichiosis after different routes of inoculation

Population kinetics of the agent of human granulocytic ehrlichiosis (aoHGE) were examined after needle and tickborne inoculation of C3H mice. Blood, skin, lung, spleen, liver, kidney, brain, lymph node, and bone marrow samples were analyzed by using real-time polymerase chain reaction (PCR) at various intervals after inoculation, using a p44 gene target. The highest number of copies of the p44 gene target occurred in blood and bone marrow samples, emphasizing aoHGE leukocytotropism. Numbers of copies of the p44 gene target in other tissues reflected vascular perfusion rather than replication. Needle-inoculated infected mice had earlier dissemination, but kinetics of infection in both groups were parallel, with declining rates of infection by day 20 and recovery in some mice on days 20-60 after inoculation. On the basis of an aoHGE lysate ELISA, mice seroconverted by day 10 after inoculation. Therefore, real-time PCR is useful for quantitative studies with the aoHGE in experimental infections, and results showed that needle inoculation can be used to study the aoHGE infection because of its similarity to tickborne inoculation.

Glycoprotein Ib/IX/V binding to the membrane skeleton maintains shear-induced platelet aggregation

The extracellular domain of glycoprotein (Gp) Ibalpha serves as the von Willebrand factor (vWf) receptor that triggers shear stress-dependent platelet aggregation. Its intracellular domain associates with actin-binding protein-280 (filamin 1a) that binds directly to filamentous actin, thereby linking the membrane skeleton to GpIbalpha. We examined the functional significance of GpIbalpha interactions with actin during platelet aggregation in response to 120 dyn/cm(2) shear stress. Lysates of resting and sheared platelets were centrifuged at approximately 13,000xg for 15 min, and GpIbalpha was immunoprecipitated from the lysate supernatant. GpIbalpha and coimmunoprecipitated proteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotted with antibodies specific for GpIbalpha and actin. We observed a significant increase in the amounts of actin coimmunoprecipitating with GpIbalpha as platelets aggregated in response to shear stress. Actin/GpIbalpha interactions reached a maximum after 90 s of shear stress. Monoclonal antibody (mAb) blockade of vWf binding to GpIbalpha inhibited shear stress-induced platelet aggregation and actin associating with GpIbalpha. Pretreatment of platelets with cytochalasin D resulted in the inhibition of actin binding to GpIbalpha in sheared platelets and in an increase in the rate and magnitude of platelet disaggregation. These data indicate that shear stress causes changes in the association between GpIbalpha and the actin-based membrane skeleton. The increased interaction between GpIbalpha and the actin-based membrane skeleton results from shear-induced vWf binding to GpIbalpha and is mechanoprotective in that it maintains shear-induced aggregation of activated platelets.

Physical origin of the Gouy phase shift

We show explicitly that the well-known Gouy phase shift of any focused beam originates from transverse spatial confinement, which, through the uncertainty principle, introduces a spread in the transverse momenta and hence a shift in the expectation value of the axial propagation constant. A general expression is given for the Gouy phase shift in terms of expectation values of the squares of the transverse momenta. Our result also explains the phase shift in front of the Kirchhoff diffraction integral.

[Establishment of trans-inactivation system for haloalkane dehalogenase gene in Arabidopsis thaliana]

With haloalkane dehalogenase gene (dhlA) of Xanthobacter autothophicus as a negative selection marker, a novel trans-inactivation system for transgenes in plants was developed. After the Arabidopsis plants were transformed with dhlA, one plant was shown dhlA post-transcriptional silencing by nuclear run-off transcriptional analysis. The Arabidopsis plants containing silencing locus were crossed to those efficiently expressed dhlA, referred as a homologous transgenic locus, and 96% of F1 plants became the homologous dhlA inactivated in trans. When the F1 plants were selfed, and the silencing locus and the homologous locus were separated in some progenies, 42 of the 200 progenies exhibited DhlA activity, and 158 no DhlA activity, and the proportion of the DhlA-expressing plants to the dhlA-silencing ones was 3.76 to 1, which suggested that the silencing locus inactivated in trans the homologous transgenic locus as a Mendelian dominant factor.

Higher-order transverse modes of ultrashort isodiffracting pulses

We present a family of space-time nonseparable analytic solutions describing spatiotemporal dynamics of isodiffracting single-cycle and few-cycle pulses with Hermite-Gaussian and Laguerre-Gaussian transverse profiles. These solutions are space-time localized wave packets propagating in free space. The transverse field profile acts as a spatially dependent filter, modifying the pulse spectrum and removing certain frequencies. The consequences of those effects in the time domain are the distortions of pulse envelope and temporal wave form and the creation of "dark pulses" at certain transverse positions. In addition, due to the space-time coupling, the instantaneous transverse field pattern changes inside the pulse, as well as with propagation distance. These higher-order mode solutions can be used to analyze reflected or scattered terahertz pulses, and to understand the wave-form distortions of terahertz signals in applications. They are also capable of modeling pulsed fields of phase locking of both transverse and longitudinal modes in total mode-locked lasers.

Effects of emulsifiers on the controlled release of paclitaxel (Taxol) from nanospheres of biodegradable polymers

Paclitaxel (Taxol) is an antineoplastic drug effective for various cancers especially ovarian and breast cancer. Due to its high hydrophobicity, however, an adjuvant such as Cremophor EL has to be used in its clinical administration, which causes serious side-effects. Nanospheres of biodegradable polymers could be an ideal solution. This study investigates the effects of various emulsifiers on the physical/chemical properties and release kinetics of paclitaxel loaded nanospheres fabricated by the solvent extraction/evaporation technique. It is shown that phospholipids could be a novel type of emulsifiers. The nanospheres manufactured with various emulsifiers were characterized by laser light scattering for their size and size distribution; scanning electron microscopy (SEM) and atomic force microscopy (AFM) for their surface morphology; zeta potential analyser for their surface charge; and, most importantly, X-ray photoelectron spectroscopy (XPS) for their surface chemistry. The encapsulation efficiency and in vitro release profile were measured by high performance liquid chromatography (HPLC). It is found that dipalmitoyl-phosphatidylcholine (DPPC) can provide more complete coating on the surface of the products which thus results in a higher emulsifying efficiency compared with polyvinyl alcohol (PVA). Our result shows that the chain length and unsaturation of the lipids have a significant influence on the emulsifying efficiency. Phospholipids with short and saturated chains have excellent emulsifying effects.

RAPD-PCR typing of Acinetobacter isolates from activated sludge systems designed to remove phosphorus microbiologically

AIMS

This study investigated whether there were differences in RAPD fingerprints between already described genomic species of Acinetobacter and those from activated sludge systems. Whether plant-specific populations of acinetobacters exist was also examined.

METHODS AND RESULTS

Fifty-two isolates of Acinetobacter from four biological phosphorus removal (EBPR) systems of different configurations, and the known genomic species, were characterized using RAPD-PCR, and fragments separated on agarose gels. Patterns were analysed using Gel Pro software and data analysed numerically. RAPD-PCR produced patterns suggesting that many environmental isolates differ from known genomic species. In two cases, strains from individual plants clustered closely enough together to imply that there may be plant-specific populations of acinetobacters.

CONCLUSION

The data suggest that current understanding of the taxonomic status of Acinetobacter may need modifying to accommodate non-clinical isolates, as many of the clusters emerging after numerical analysis of RAPD-PCR fragments from activated sludge isolates were quite separate from the clusters containing the already described genomic species. Some evidence was also obtained from the clusters generated to support a view that particular populations of Acinetobacter may occur in individual activated sludge plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

These data suggest that the current understanding of the systematics of Acinetobacter, based as it is almost exclusively on clinical isolates, may need drastic revision to accommodate environmental strains. They also suggest that a re-examination of the importance and role of Acinetobacter in the activated sludge process may be appropriate.

New materials in hydrothermal synthesis

In this Account we describe the hydrothermal synthesis of some new materials including microporous crystals, ionic conductors, complex oxides and fluorides, low-dimensional aluminophosphates, inorganic-organic hybrid materials, and particularly condensed materials such as diamond and inorganic helical chains. Hydrothermal synthesis in biology and environment sciences is also introduced. The increasing interest in hydrothemal synthesis derives from its advantages in terms of high reactivity of reactants, easy control of solution or interface reactions, formation of metastable and unique condensed phases, less air pollution, and low energy consumption.

Analysis of methadone and its metabolites in meconium by enzyme immunoassay (EMIT) and GC-MS

An EMIT-ETS d.a.u. immunoassay screening method for methadone in meconium and a gas chromatography-mass spectrometry (GC-MS) method for methadone and its metabolites including 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyrroline (EMDP) in meconium were described. The GC-MS method showed good linearity (r2 > or = 0.998) over a concentration range of 25-2000 ng/g with limits of detection of 10, 25, and 10 ng/g for methadone, EDDP, and EMDP, respectively, and a limit of quantitation of 25 ng/g for all three analytes. Fifty pooled meconium samples were screened using a cutoff of 200 ng/g, and all samples screened negative. GC-MS analysis of all samples showed four samples to contain methadone (35.2 to 79.9 ng/g), EDDP (28.5 to 557.2 ng/g), or both, with no detectable amount of EMDP. The negative results on the four specimens at the cutoff used may be explained by the fact that EMIT-ETS d.a.u. antibody for methadone was specific to the parent drug. The results point to the fact that immunoassays should be directed to EDDP for detection of prenatal exposure of methadone through analysis of meconium specimens.

[The association and linkage analysis between the FcgammaR II a-131 and system lupus erythematosus]

OBJECTIVE

To shed light on the relationship between FcgammaR II a-131 and systemic lupus erythematosus(SLE) in southern Chinese Han population.

METHODS

A population-based and family-based study was carried out. FcgammaR II a-131 of each subject was measured by using PCR-allele specific oligonucleotide hybridization(ASO) method.

RESULTS

(1) The distribution of FcgammaR II A-131 genotype in cases is significantly different from that in controls (P<0.05). So is the frequency of FcgammaR II aR-131 allele (P < 0.01) which suggests that subjects who have R131 allele tend to be more susceptible to SLE. The subjects with R/R131 homozygous genotype have a higher risk of suffering from SLE. (2) The distribution of FcgammaR II a-131 varies in different races, with identical distribution type among Chinese and Japanese. (3) The results of family-based association analysis and transmitted/disequilibrium test(TDT) suggest that there is not any linkage evidence between FcgammaR II a-131 and SLE. Possibly, the sample size was too small to get positive result.

CONCLUSION

This study suggests that FcgammaR II a-131 is a major factor predisposing to the development of SLE in southern Chinese Han population.

Cavity phase engineering for stable enhanced terahertz pulse trains

We show that the cavity round-trip Gouy phase leads to pulse-to-pulse variation of the absolute phase and temporal profile of circulating few- or single-cycle pulses in empty resonators. This pulse-to-pulse variation can be eliminated by the proper insertion of a lens into the cavity. An application to terahertz resonators with phase-locked feedback is discussed.

[Evaluation of derma and fat combined pedicled superficial temporal fascia flap for reconstruction of facial depression]

OBJECTIVE

To evaluate the curative effect of derma and fat combined pedicled superficial temporal fascia flap for reconstruction of facial depression.

METHOD

Postoperative follow-up and comparative study were performed. 10 cases of facial depression deformities were involved, in which 5 cases were hemifacial atrophy, and 5 cases were branchial arch maldevelopment.

RESULTS

Postoperative follow-up for 1-3 years showed that the method produced better results in branchial arch depression than in hemifacial atrophy. The combined tissue used in plomb of branchial arch maldevelopment had a low ratio of anaphase absorption, maintaining a satisfactory long-term full contour. In plomb of hemifacial atrophy, the anaphase absorption ratio of the was combined tissue approximately 20%-40%.

CONCLUSIONS

The noxa of depression ought to be noticed when this method is used in reconstruction of facial depression. The exorbitant plomb is inadvisable for facial depression of branchial arch maldevelopment. However, in facial depression of hemifacial atrophy, in considering anaphases absorption, the suitable exorbitant plomb is reasonable for better future results.

Simultaneous analysis of delta9-THC and its major metabolites in urine, plasma, and meconium by GC-MS using an immunoaffinity extraction procedure

A simple extraction procedure for delta9-tetrahydrocannabinol (delta9-THC) and its metabolites from various biological specimens was developed based on immunoaffinity chromatography. Using the affinity resin prepared by immobilization of THC antibody onto cyanogen bromide-activated Sepharose 4B, delta9-THC and its major metabolites including 11-nor-delta9-THC-9-carboxylic acid (delta9-THCCOOH), 11-hydroxy-delta9-THC (11-OH-delta9-THC), and 8beta,11-dihydroxy-delta9-THC (8beta,11-diOH-delta9-THC) were extracted simultaneously from plasma or urine after enzyme hydrolysis. The samples were derivatized as TMS derivatives and analyzed by gas chromatography-mass spectrometry in EI mode with SIM monitoring. Greater than 87% extraction recovery of the four analytes was obtained from both plasma and urine at 5 and 50 ng/mL concentration levels. The method was also used for meconium analysis with some modification. The extraction recovery from meconium, however, was lower than that of plasma and urine, ranging from 52 to 72% at the 10-ng/g level. All compounds showed good linearity within the tested ranges up to 100 ng/mL (g). The limits of detection ranged from 0.5 to 2.5 ng/mL in plasma and urine, and from 1.0 to 2.5 ng/g in meconium. Analysis of 24 meconium specimens showed that 11-OH-delta9-THC is indeed an important metabolite in meconium.

Endothelial-like cells from the bovine placental cotyledon

A cell-line was established from bovine placental cotyledon. When cultured in M199 with 10% fetal bovine serum, this cell-line had a doubling time of about 18 h. With immunohistochemistry, it was demonstrated that this cell-line expressed vimentin and angiotensin-converting enzyme (ACE). While both molecules are expressed in endothelial cells, ACE is usually considered to be a specific marker for endothelial cells. Furthermore, cells were shown to take up Dil-Ac-LDL (acetylated low-density lipoprotein labeled with 1,1'-dioctadecyl-3,3,3'-tetramethylindo-carbocyanine perchlorate). This characteristic feature has been used to identify endothelial cells. Finally, when cultured on matrigel, this cell-line formed tube-like structures similar to those formed by endothelial cells. Tube-formation on matrigel is a physiological property specific to endothelial cells. In conclusion, these three lines of evidence strongly suggest that this cell-line is endothelial cell in nature. Further studies using an endothelial cell-line from bovine placenta may help to elucidate the cause of bovine placental retention, a major cause for economic loss in bovine industry. Furthermore, an endothelial cell-line could be an important tool in research areas such as tissue remodeling, angiogenesis, and cancer.

In vivo and in vitro modulation of immune stimulatory capacity of primary dendritic cells by adenovirus-mediated gene transduction

Dendritic cells (DCs) are potent antigen-presenting cells which are key leukocytes in the initiation of cell-mediated organ graft rejection, antiviral immunity, and antitumor responses. In this study we demonstrate that genetic modification of primary human and mouse DCs by adenoviral gene transfer is an effective means of induction and modulation of antigen presentation by DCs. An adenovirus vector (AdLacZ) was used to express an intracellular model antigen beta-galactosidase (beta-gal) in DCs. Our results show that 30-40% of precursor dendritic cells (PDCs) derived from human umbilical cord blood and circulating mature blood DCs express high levels beta-galactosidase (beta-gal) after infection with AdLacZ with no cytopathic effect observed. In vitro, AdLacZ transduced PDCs and DCs demonstrated a 10- to 20-fold higher mixed lymphocyte reaction (MLR) stimulatory capacity as compared to that of monocytes. In vivo, immunization with AdLacZ transduced mouse DCs resulted in more potent cytotoxic T lymphocyte (CTL) responses against the predicted H-2 restricted beta-gal epitope as compared to CTL responses obtained by beta-gal peptide pulsed DCs. Modulations of the MLR stimulatory capacity of DCs were examined by expression of mouse B7 and CTLA-4Ig. The results show that expression of mouse B7 by a recombinant adenoviral vector (Ad7) significantly enhances the MLR stimulatory capacity of human DCs. In contrast, expression of CTLA-4Ig (AdCTLA-4Ig) reduces the MLR stimulatory capacity of the transduced cells. We conclude that recombinant adenovirus can readily be used for genetic modulation DC-induced immune responses in vivo and in vitro. DCs targeted for induction of specific antigen responses or for modulation of the immune stimulatory capacity may have a potential use in the control of transplantation rejection or viral infections.

[The impact of hepatitis B virus infected patients or donors on the outcome of hematopoietic stem cell transplantation]

OBJECTIVE

To investigate the impact of recipients and/or donors infected with hepatitis B on the outcome of hematopoietic stem cells transplantation (HSCT).

METHODS

We analyzed retrospectively the transplantation outcome in 26 of 164 hematological diseases patients who and whose donors were infected with hepatitis prior to transplantation.

RESULTS

(1) Three of the 26 patients developed VOD after HSCT, the incidence (11.5%) is significant higher than that in patients and donors who did not infected with HBV (P < 0.05). (2) Two of 5 patients transfused hematopoietic stem cells from HBsAg + donors developed hepatitis B. (3) Four patients with allogeneic stem cell transplantation developed hepatic failure (HF) which occurred during cyclosporin (CsA) being tapered off or withdrawal. The incidence of HF in patients and/or donors infected with HBV (15.4%) is obviously higher than that in patients and donors who did not (0.08%, P < 0.01). (4) In 4 patients with HbeAg +, 2 patients died of HF after allogeneic HSCT, the other 2 patients survived after autologous HSCT.

CONCLUSION

Donors and recipients infected with hepatitis B are not contraindication of HSCT, but patients with allogeneic HSCT are in danger to develop LF during CsA being tapered off or withdrawal.

Lyme arthritis resolution with antiserum to a 37-kilodalton Borrelia burgdorferi protein

A 37-kDa protein from Borrelia burgdorferi (the agent of Lyme disease) was identified as a target for immune-mediated resolution of Lyme arthritis. Studies in a mouse model have shown that arthritis resolution can be mediated by antibodies (against unknown target antigens) within immune sera from actively infected mice. Immune sera from infected mice were therefore used to screen a B. burgdorferi genomic expression library. A gene was identified whose native product is a putative lipoprotein of approximately 37 kDa, referred to here as arthritis-related protein (Arp). Active and passive immunization of mice with recombinant Arp or Arp antiserum, respectively, did not protect mice from challenge inoculation. However, when Arp antiserum was administered to severe combined immunodeficient (SCID) mice with established infections and with ongoing arthritis and carditis, treatment selectively induced arthritis resolution without affecting the status of carditis or influencing the status of infection, including spirochetemia. The selective arthritis-resolving effect of Arp antiserum mimics the activity of immune serum from immunocompetent mice when such serum is transferred into SCID mice with established infections. The arp gene could not be amplified from unrelated B. burgdorferi isolates but hybridized with those isolates only under very-low-stringency conditions. Arp antiserum reacted against proteins of similar size in a wide range of B. burgdorferi isolates.

Electrophoretic affinity chromatography: method validation

A new method for preparative-scale separation of biomolecules, electrophoretic affinity chromatography (EAC), is proposed in this paper. Separation by EAC is carried out in a long and ribbon-like multicompartment electrolyser separated by membranes, in which the two central compartments are used for packing the gel matrix and for sample loading respectively. Next to the central compartments are the elution compartments and electrode compartments. The electric field is applied perpendicular to the fluid flow in the compartments. Adsorption and desorption steps may both be carried out in the presence of an electric field, which transports the target components into the gel compartment for adsorption and the impurities into the elution compartments for washing. After the adsorption step an elution solution is introduced and the product is released from the gel matrix and washed out. Separation of human serum albumin (HSA) from human serum gives HSA product of high purity, as demonstrated by isoelectric focusing analysis. The characteristics of electrophoretic binding of HSA on Blue Sepharose Fast Flow are examined. The preliminary results show that this new method has advantages in terms of high rate of mass transfer and ease of scaling up, which are of particular interest when large-scale separation of biomolecules is considered.

No correlation of polymorphism of angiotensin-converting enzyme genes with left ventricular hypertrophy in essential hypertension

To investigate the correlation of polymorphism of angiotensin-converting enzyme (ACE) genes with left ventricular hypertrophy in essential hypertension, 151 patients with essential hypertension were studied. ACE genotypes were determined by PCR technology and diastolic left ventricular diameter (DLVd), systolic left ventricular diameter (SLVd), interseptal ventricular thickness (IVS), and left ventricular posterior wall thickness (LVPW) were scanned by echocardiography. Left ventricular mass (LVM) and the left ventricular mass index (LVMI) were calculated from echocardiographic findings. Results revealed that DLVd, SLVd, IVS, LVPW, LVM, and LVMI of the DD genotype group were 49.9 +/- 5.6 mm, 30.5 +/- 6.5 mm, 11.2 +/- 1.6 mm, 11.7 +/- 1.5 mm, 259.5 +/- 62.1 g, 92.7 +/- 23.5 g/m2, respectively. DLVd, SLVd, IVS, LVPW, LVM, and LVMI of the ID genotype group were 8.9 +/- 5.3 mm, 31.5 +/- 5.2 mm, 11.4 +/- 1.7 mm, 11.9 +/- 1.6 mm, 261.3 +/- 70.3 g, and 94.9 +/- 25.8 g/m2, respectively, and DLVd, SLVd, IVS, LVPW, LVM, and LVMI of the II genotype group are 48.9 +/- 5.5 mm, 31.8 +/- 6.5 mm, 11.1 +/- 1.9 mm, 11.5 +/- 1.8 mm, 250.8 +/- 82.5 g and 90.8 +/- 30.1 g/m2 respectively. There was no significant difference between the ID, DD and II genotype groups as regards DLVd, SLVd, IVS, LVPW, LVM, and LVMI (p > 0.05). These findings indicate that there is no association between the ACE gene and left ventricular hypertrophy in essential hypertension occurring in the Chinese population.

The galE gene of Campylobacter jejuni is involved in lipopolysaccharide synthesis and virulence

Lipopolysaccharide (LPS) is one of the main virulence factors of gram-negative bacteria. The LPS from Campylobacter spp. has endotoxic properties and has been shown to play a role in adhesion. We previously cloned a gene cluster (wla) which is involved in the synthesis of the Campylobacter jejuni 81116 LPS molecule. Sequence alignment of the first gene in this cluster indicated similarity with galE genes. These genes encode a UDP-glucose 4-epimerase, which catalyzes the interconversion of UDP-galactose and UDP-glucose. A Salmonella galE mutant was transformed with the galE gene from C. jejuni. The LPS analysis of wild-type, galE, and complemented galE Salmonella strains showed that the C. jejuni galE gene could restore the smooth wild-type Salmonella LPS. A UDP-glucose 4-epimerase assay was used to demonstrate that the galE gene from C. jejuni encoded this epimerase. We constructed a C. jejuni galE mutant which expressed a lipid A-core molecule of reduced molecular weight that did not react with antiserum raised against the parental strain. These results show an essential role for the galE gene in the synthesis of C. jejuni LPS. The galE mutant also showed a reduction in its ability to adhere to and invade INT407 cells. However, it was still able to colonize chickens to the same level as the wild-type strain. The serum resistance and hemolytic activity of this mutant were not changed compared to the parent strain. The ability of the mutant to take up DNA and integrate it in its genome was reduced 20-fold. These results show that LPS of C. jejuni is an important virulence factor.

A dendritic cell line genetically modified to express CTLA4-IG as a means to prolong islet allograft survival

BACKGROUND

Dendritic cells are potent antigen-presenting cells that bind allogeneic T cells. They are thus candidates for targeting immunoregulatory molecules to the alloreactive T cell compartment and suppressing the alloimmune response.

METHOD

A dendritic cell line derived from the BALB/c mouse (H2d) was genetically modified to express the immunoregulatory molecule CTLA4-Ig. The ability of these dendritic cell transfectants to downregulate the alloimmune response was tested in an islet transplant model. Allogeneic C57Bl/6 (H2b) mice were rendered diabetic with streptozocin, and they received BALB/c islet (H2d) transplants. Mice were administered 25 million untransfected or CTLA4-Ig-transfected D2SC/1 cells i.v. on the day of islet transplantation and 6 days later[fnc].

RESULT

Mice treated with CTLA4-Ig-transfected D2SC/1 cells demonstrated prolonged allograft survival (mean = 20 days, median = 17 days, SD = 9.39) compared with mice treated with untransfected D2SC/1 cells (mean = 12 days, median = 11 days, SD=2.74) or untreated control mice (mean = 11 days, median = 11 days SD = 1.41). Third party allograft survival was not prolonged in mice receiving similar treatment.

CONCLUSIONS

These results demonstrate that a genetically modified dendritic cell line can suppress the alloimmune response and prolong islet allograft survival in an allospecific manner. The findings also suggest that genetically modified dendritic cells may be useful in targeting alloreactive T cells and prolonging allograft survival.