HIV-1-specific CTL responses primed in vitro by blood-derived dendritic cells and Th1-biasing cytokines

Vaccine strategies designed to elicit strong cell-mediated immune responses to HIV Ags are likely to lead to protective immunity against HIV infection. Dendritic cells (DC) are the most potent APCs capable of priming both MHC class I- and II-restricted, Ag-specific T cell responses. Utilizing a system in which cultured DC from HIV-seronegative donors were used as APC to present HIV-1 Ags to autologous T cells in vitro, the strength and specificity of primary HIV-specific CTL responses generated to exogenous HIV-1 Nef protein as well as intracellularly expressed nef transgene product were investigated. DC expressing the nef gene were able to stimulate Nef-specific CTL, with T cells from several donors recognizing more than one epitope restricted by a single HLA molecule. Primary Nef-specific CTL responses were also generated in vitro using DC pulsed with Nef protein. T cells primed with Nef-expressing DC (via protein or transgene) were able to lyse MHC class I-matched target cells pulsed with defined Nef epitope peptides as well as newly identified peptide epitopes. The addition of Th1-biasing cytokines IL-12 or IFN-alpha, during priming with Nef-expressing DC, enhanced the Nef-specific CTL responses generated using either Ag-loading approach. These results suggest that this in vitro vaccine model may be useful in identifying immunogenic epitopes as vaccine targets and in evaluating the effects of cytokines and other adjuvants on Ag-specific T cell induction. Successful approaches may provide information important to the development of prophylactic HIV vaccines and are envisioned to be readily translated into clinical DC-based therapeutic vaccines for HIV-1.

Autologous human monocyte-derived dendritic cells genetically modified to express melanoma antigens elicit primary cytotoxic T cell responses in vitro: enhancement by cotransfection of genes encoding the Th1-biasing cytokines IL-12 and IFN-alpha

DNA-based immunization strategies designed to elicit cellular antitumor immunity offer an attractive alternative to protein- or peptide-based approaches. In the present study we have evaluated the feasibility of DNA vaccination for the induction of CTL reactivity to five different melanoma Ags in vitro. Cultured, monocyte-derived dendritic cells (DC) were transiently transfected with plasmid DNA encoding human MART-1/Melan-A, pMel-17/gp100, tyrosinase, MAGE-1, or MAGE-3 by particle bombardment and used to stimulate autologous PBMC responder T cells. CTL reactivity to these previously identified melanoma Ags was reproducibly generated after two or three stimulations with genetically modified DC. Co-ordinate transfection of two melanoma Ag cDNAs into DC promoted CTL responders capable of recognizing epitopes from both gene products. Coinsertion of genes encoding the Th1-biasing cytokines IL-12 or IFN-alpha consistently enhanced the magnitude of the resulting Ag-specific CTL reactivity. Importantly, DC transfected with a single melanoma Ag cDNA were capable of stimulating Ag-specific CTL reactivity restricted by multiple host MHC alleles, some of which had not been previously identified. These results support the inherent strengths of gene-based vaccine approaches that do not require prior knowledge of responder MHC haplotypes or of relevant MHC-restricted peptide epitopes. Given previous observations of in situ tumor HLA allele-loss variants, DC gene vaccine strategies may elicit a greater diversity of host therapeutic immunity, thereby enhancing the clinical utility and success of such approaches.

Serotonin regulates synaptic connections in the dentate molecular layer of adult rats via 5-HT1a receptors: evidence for a glial mechanism

The present study sought to verify effects of 5-HT on synaptic density at the ultrastructural level, to determine whether the 5-HT1a receptor is important for the maintenance of synaptic connections and to obtain evidence implicating S100 beta in the apparent neurotrophic actions of 5-HT. Reduction of hippocampal 5-HT with para-chloroamphetamine (PCA) resulted in a significant decline in the synaptic density of the dentate molecular layer. Reduction of norepinephrine with DSP-4 produced a slight decrease in the number of molecular layer synapses, but this difference was not statistically different from control values. 5-HT1a antagonist treatment resulted in a decline in synaptic density comparable to that observed following PCA treatment. These observations suggest that 5-HT functions to maintain synaptic connections in the dentate molecular layer via a 5-HT1a mechanism. To determine whether the change in synaptic density was due to the action of 5-HT on neuronal receptors or astrocytic receptors, a monoclonal antibody against S100 beta was infused into the lateral ventricle for seven days. Controls received infusions of normal goat serum. Half of the rats from the anti-S100 beta and control groups also received daily injections of NAN-190. Anti-S100 beta infusion resulted in a significant (p < 0.01) decrease in synapses compared to serum controls. Concomitant NAN-190 administration did not enhance synapse loss in the anti-S100 beta group. The results of this study suggest that the maintenance of synaptic connections in the dentate molecular layer is influenced by S100 beta levels that are controlled by 5-HT stimulation of astrocytic 5-HT1a receptors.

Effects of neonatal serotonin depletion on the development of rat dentate granule cells

The appearance of serotonergic (5-HT) neurons and projections early in central nervous system (CNS) development has resulted in the hypothesis that 5-HT is an important factor in neuronal differentiation and synaptogenesis. Studies of the effects of 5-HT on the development of molluscan and mammalian neurons in vitro support this hypothesis, but mammalian in vivo studies have produced equivocal results. The present study reinvestigated the role of 5-HT in CNS development using the dentate granule cell as a model. Dentate granule cells were chosen for this study of the effects of 5-HT depletion on neuronal development because they are generated in the early postnatal period. Thus, 5-HT depletion could be effected by the treatment of rat pups with either parachloroamphetamine (PCA) or 5,7-dihydroxytryptamine (5,7-DHT) thereby avoiding problems inherent in maternal treatment paradigms. The morphology of Neurobiotin-filled granule cells was studied on P14, P21, P60 and P120 (P0 = day of birth). The parameters measured were total dendritic length, number of dendritic segments and dendritic spine density (number of spines/50 microns dendritic length). Granule cells from vehicle-treated controls were similar to those previously reported in studies of normal granule cell development in all respects. In particular, the decrease in dendritic spine density from P14 to P120 observed in Golgi preparations was verified in our population of intracellularly filled granule cells. Transient depletion of 5-HT by neonatal PCA treatment resulted in a decrease dendritic length that was not statistically different from control values. However, dendritic spine density was reduced by about 27% at all ages studied. 5,7-DHT treatment produces a permanent, severe depletion of 5-HT. Spine densities in granule cells from 5,7-DHT-treated pups were also about 38% lower than controls. Total dendritic length in cells from 5,7-DHT-treated rats was reduced to a degree comparable to that observed in PCA-treated pups. The number of granule cell dendritic segments was also less than that observed in control and PCA-treated rats but this difference was not statistically significant. These observations suggest that reduction of 5-HT in the early postnatal period can result in changes in the morphology of dentate granule cells, particularly at the level of the synapse as reflected by the permanent reduction in synaptic spine density. The comparison of results from cases with permanent and transient reduction of 5-HT indicates that the developmental influence of 5-HT is most important during the first three postnatal weeks.

5-HT1a receptors mediate the neurotrophic effect of serotonin on developing dentate granule cells

We have previously reported that neonatal (P3) serotonin (5-HT) depletion results in a significant decrease in the number of dendritic spines per 50 microns of dendritic length on dentate granule cells. This effect is specific and permanent. Neither total dendritic length nor the number of dendritic segments is affected by 5-HT depletion. The area dentata contains a dense 5-HT1a receptor population that is present in the at birth. Therefore, 5-HT1a receptors represented a likely candidate for the mediation of the effects of 5-HT on developing granule cells. The present study used the drugs buspirone and NAN-190, which have been shown to be an agonist and antagonist respectively at postsynaptic 5-HT1a receptors in vivo, to test the idea that neurotrophic actions of 5-HT result from 5-HT1a receptor stimulation. Following 5-HT depletion with PCA, pups received daily injections of buspirone (1.0 mg/kg) from P5 to P14. Granule cell morphology was then studied using intracellular filling with Neurobiotin on P14, P21 and P60. Buspirone treatment prevented the loss of dendritic spines previously shown to follow 5-HT depletion with PCA. No other morphological parameters were significantly changed by buspirone treatment. Naive pups received daily injections of NAN-190 from P3 to P14. One group received 1.0 mg/kg while a second group received 3.5 mg/kg. Both doses of NAN-190 resulted in dendritic spine loss comparable to that obtained with neonatal PCA treatment. This loss was permanent suggesting that the first two postnatal weeks may represent a critical period for the action of 5-HT on developing granule cells. Significant, dose-dependent changes in total dendritic length and number of dendritic segments reminiscent of the effects of norepinephrine depletion were also observed in NAN-190-treated rats. We suspect that this change is the result of the action NAN-190 at alpha receptors and is therefore distinct from the specific effect of 5-HT on the number of dendritic spines. The NAN-190 experiment also shows that the loss of dendritic spines is a function of decreased stimulation of 5-HT1a receptors and not the loss of 5-HT terminal membrane.

Overlapping epitopes in human immunodeficiency virus type 1 gp120 presented by HLA A, B, and C molecules: effects of viral variation on cytotoxic T-lymphocyte recognition

Human immunodeficiency virus (HIV)-specific cytotoxic T lymphocytes (CTL) are thought to exert immunologic selection pressure in infected persons, yet few data regarding the effects of this constraint on viral sequence variation in vivo, particularly in the highly variable Env protein, are available. In this study, CD8+ HIV type 1 (HIV-1) envelope-specific CTL clones specific for gp120 were isolated from peripheral blood mononuclear cells of four HIV-infected individuals, all of which recognized the same 25-amino-acid (aa) peptide (aa 371 to 395), which is partially contained in the CD4-binding domain of HIV-1 gp120. Fine mapping studies revealed that two of the clones optimally recognized the 9-aa sequence 375 to 383 (SFNCGGEFF), while the two other clones optimally recognized the epitope contained in the overlapping 9-aa sequence 376 to 384 (FNCGGEFFY). Lysis of target cells by the two clones recognizing aa 375 to 383 was restricted by HLA B15 and Cw4, respectively, whereas both clones recognizing aa 376 to 384 were restricted by HLA A29. Sequence variation, relative to the IIIB strain sequence used to identify CTL clones, was observed in autologous viruses in the epitope-containing region in all four subjects. However, poorly recognized autologous sequence variants were predominantly seen for the A29-restricted clones, whereas the clones specific for SFNCGGEFF continued to recognize the predominant autologous sequences. These results suggest that the HLA profile of an individual may not only be important in determining the specificity of CTL recognition but may also affect the ability to recognize virus variants and suppress escape from CTL recognition. These results also identify overlapping viral CTL epitopes which can be presented by HLA A, B, and C molecules.

Time-of-flight Laue fiber diffraction studies of perdeuterated DNA

The diffractometer SXD at the Rutherford Appleton Laboratory ISIS pulsed neutron source has been used to record high resolution time-of-flight Laue fiber diffraction data from DNA. These experiments, which are the first of their kind, were undertaken using fibers of DNA in the A conformation and prepared using deuterated DNA in order to minimise incoherent background scattering. These studies complement previous experiments on instrument D19 at the Institut Laue Langevin using monochromatic neutrons. Sample preparation involved drawing large numbers of these deuterated DNA fibers and mounting them in a parallel array. The strategy of data collection is discussed in terms of camera design, sample environment and data collection. The methods used to correct the recorded time-of-flight data and map it into the final reciprocal space fiber diffraction dataset are also discussed. Difference Fourier maps showing the distribution of water around A-DNA calculated on the basis of these data are compared with results obtained using data recorded from hydrogenated A-DNA on D19. Since the methods used for sample preparation, data collection and data processing are fundamentally different for the monochromatic and Laue techniques, the results of these experiments also afford a valuable opportunity to independently test the data reduction and analysis techniques used in the two methods.

DNA hydration studied by neutron fiber diffraction

The development of neutron high angle fiber diffraction to investigate the location of water around the deoxyribonucleic acid (DNA) double-helix is described. The power of the technique is illustrated by its application to the D and A conformations of DNA using the single crystal diffractometer, D19, at the Institut Laue-Langevin. Grenoble and the time of flight diffractometer, SXD, at the Rutherford Appleton ISIS Spallation Neutron Source. These studies show the existence of bound water closely associated with the DNA. The patterns of hydration in these two DNA conformations are quite distinct and are compared to those observed in X-ray single crystal studies of two-stranded oligodeoxynucleotides. Information on the location of water around the DNA double-helix from the neutron fiber diffraction studies is combined with that on the location of alkali metal cations from complementary X-ray high angle fiber diffraction studies at the Daresbury Laboratory SRS using synchrotron radiation. These analyses emphasize the importance of viewing DNA, water and ions as a single system with specific interactions between the three components and provide a basis for understanding the effect of changes in the concentration of water and ions in inducing conformational transitions in the DNA double-helix.

Hydrogen-Atom Ordering in Lead Hydrogen Arsenate Monitored by Neutron Time-of-Flight Laue Diffraction using Single-Frame Methods

The ordering of the hydrogen atom in a single crystal of lead hydrogen arsenate in the temperature range 320 to 80 K is described. The details of the ordering at small temperature steps are determined from single frames of data collected using the neutron time-of-flight Laue method. The constrained refinements obtained from these data yield lower precision than full data sets but allow the ordering to be characterized rapidly and reliably. This is the first example of the use of this single-frame method of monitoring such phase transitions. The approach used here with neutrons, stimulated in part by synchrotron Laue diffraction, will be of interest for all time-resolved experiments with synchrotron radiation or neutrons.

Ex vivo expansion of CD4 lymphocytes from human immunodeficiency virus type 1-infected persons in the presence of combination antiretroviral agents

Expansion of CD4 lymphocytes from human immunodeficiency virus type 1 (HIV-1)-infected persons ex vivo has been limited by enhanced virus replication and cell death. The successful expansion of functional CD4 lymphocytes from HIV-1-infected persons has now been accomplished using a bispecific monoclonal antibody to CD3 and CD8 in combination with three antiretroviral agents. CD4 lymphocytes were polyclonally expanded by a factor of 10(3)-10(7) during 4-8 weeks in culture. Supernatants from most cultures were persistently HIV-1 p24 antigen-negative by day 14 and remained negative despite removal of antiretroviral agents at day 28. In such cultures, HIV-1 could not be recovered by cocultivation, and amounts of HIV-1 DNA declined or remained stable at low levels, eventually becoming undetectable in 2 cases. This approach establishes the feasibility of CD4 lymphocyte expansion in persons with HIV disease and may be useful for immune-based or gene therapies.

Transient reduction in hippocampal serotonergic innervation after neonatal parachloroamphetamine treatment

This study examined the effects of parachloroamphetamine on neonatal forebrain serotonergic (5-HT) innervation. Rat pups were treated with PCA on P3 and P4. Significant reductions in 5-HT content were observed in the hippocampal formation, frontal cortex and entorhinal cortex on P5 and P7. By P14, neocortical 5-HT had returned to normal levels while hippocampal 5-HT values remained less than control. Hippocampal 5-HT content reached normal range by P21. High affinity 5-HT uptake in hippocampal synaptosomal preparations was similarly reduced on P5 and P7 suggesting that 5-HT terminals were being lesioned by PCA. 5-HT uptake recovered significantly by P14 perhaps reflecting the extraordinary plasticity of the 5-HT projections in the neonate. However, in contrast to the complete restoration of hippocampal 5-HT content, 5-HT uptake values remained significantly less than control. No change in 5-HT content was observed in either the hypothalamus or midbrain raphe at any age studied. Thus, the rapid onset of effects, regional selectivity and transient reduction of 5-HT levels recommend the use of PCA in studies of the role of 5-HT in hippocampal development.

Calcium channel blockers in the treatment of hypertension

Physicians need to weigh the efficacy, adverse effects and cost of first-line antihypertensive agents. Calcium channel blockers lower blood pressure, improve coronary blood flow and depress cardiac contractility by relaxing smooth muscle and cardiac muscle. They have beneficial or neutral effects in hypertensive patients with angina, asthma, chronic obstructive pulmonary disease, postural hypotension, peripheral vascular disease, depression, sexual dysfunction, diabetes and hyperlipidemia. The major adverse effect of some calcium channel blockers is that they may worsen congestive heart failure in some patients. Because calcium channel blockers are metabolized in the liver, the dosage must be lowered in the elderly and in patients with hepatic disease. Diltiazem, verapamil and nifedipine represent prototypes of the three classes of calcium channel blockers, each with slightly different effects.

State unit on aging involvement with continuing care retirement community (CCRC) legislation

State units on aging (SUAs) from 29 states with continuing care retirement community (CCRC) legislation were surveyed to (a) assess staff familiarity with CCRC legislation, (b) examine interdepartmental working relationships surrounding such legislation and ask what role(s) ombudspersons are playing in CCRC oversight, (c) determine what role(s) aging units have had in developing legislation, and (d) gain insights regarding legislative impact. Results indicate that SUAs have been active in legislative development but vary greatly in the intensity of their involvement with the implementation and enforcement of CCRC regulation and in their perception of legislative impact.

The pet as an anxiolytic intervention

The effect of a pet on psychological consequences of stress (i.e., state and trait anxiety levels) of college students was examined under three test conditions (i.e., reading aloud, reading quietly, and interacting with a friendly but unknown dog). A repeated-measures analysis of variance with three covariates was used to examine the effect of the treatment on each dependent variable (state and trait anxiety). Reading aloud differed from baseline measure under all treatment conditions (p less than .001). Reading quietly and interacting with the dog were slightly below baseline for variables, with more effect seen by reading quietly than by interacting with the dog. Examination of interactions among variables showed no significant differences. Effects upon state anxiety were significant, while trait anxiety levels remained fairly constant throughout the treatments. Baseline differences in trait anxiety scores indicate a potentially greater benefit for pet owners than nonowners. Selected social network and relationship data related to the role of the pet during anxiety-producing times were also analyzed. While interaction with the pet produced a decrease in anxiety level, pet owners did not report the use of their own pet as a social support (i.e., as confidant) significantly more than did previous owners. Results indicated that interacting with a pet for some individuals does affect both physiological and psychological responses by lowering response levels. However, a parallel effect was also seen by reading quietly. Given the effect of pet interaction upon selected social support indicators of health in well college students, these data suggest the importance of examining this treatment with an "at-risk" group in which it is possible to control for ownership characteristics.

CCRC statutes: the oversight of long-term care service delivery

A 1987 national survey revealed 27 states with continuing care or life care legislation. State oversight staff in 22 states responded to questions concerning characteristics of the regulated continuing care retirement community (CCRC) industry, the regulation of health and human service delivery within CCRCs, and interdepartmental working relationships between oversight agencies and other state units. Discussion focuses on the regulation of long-term care service provision in the CCRC industry.

Lessons from the implementation of CCRC regulation

Oversight staff in 23 of the 30 states with legislation regulating continuing care retirement communities (CCRCs) completed a questionnaire surveying features of implementation experience such as problems encountered with the scope of regulation, the appropriateness of oversight placement, the adequacy of staff and financial resources, the use of discretionary agency authority, and attitudes toward various changes in applicable state law. These findings have relevance for consumers, legislators, lobbyists, and professionals working to make CCRCs a responsible long-term care alternative.

Psychogenic amnesia

Psychogenic amnesia is a psychiatric disorder characterized by sudden loss of memory in the absence of organic lesion or disease. The disorder most frequently occurs in association with a severe stressor, such as a natural disaster or military conflict. To facilitate effective treatment and an accurate prognosis, psychogenic amnesia must be differentiated from amnesia of structural or pharmacologic origin. Treatment may involve supportive psychotherapy, behavioral modification or pharmacotherapy. Prognosis for complete recovery is generally good.

Analysis of conformational parameters in nucleic acid fragments. IV. Intercalating drug complexes of very short chain oligonucleotides

Studies have been made of base-pairing conformational parameters in single crystal structures of very short chain oligonucleotide structures complexed with drug molecules, using data extracted from the Cambridge structural database. The planar portion of the drug has a tendency to intercalate between two bases, utilising strong stacking interactions to stabilise the configuration. The effect of the existence of a formative backbone is seen in the high occurrence of standard base-pairing schemes and a consistent C1'-C1' separation, although the choice of compounds studied does tend to emphasise complementary pairing. In addition to the modulation of the general magnitude which is reduced from that in uncomplexed oligonucleotides, there appears to be some correlation of propeller twist value with the presence of planar groups sandwiching a base-pair. The average twist in such sandwiched pairs is lower than in any other group studied to date.

Analysis of conformational parameters in nucleic acid fragments. III. Very short chain oligonucleotides. The effect of base stacking

Studies have been made of conformational parameters in single crystal structures of very short chain oligonucleotides consisting of strands with lengths in the range 2-3 bases. Using published data extracted from the Cambridge structural database for 20 such structures, a total of 14 base-pairs were found, of which 10 were hetero-pairs and 4 homo-pairs. Subjecting these to analysis to examine hydrogen bond parameters, propeller twist, buckle and C1'-C1' separation revealed an average propeller twist of 11.6 degrees, with no dependence of this parameter on hydrogen bonding details. In addition, an analysis of base stacking showed there to be no correlation between in-plane geometry and degree of inter-plane overlap.

State screening for metabolic disorders in newborns

Most states have mandatory screening programs for congenital and inherited disorders of metabolism. Physicians may be unaware of their state's requirements, and compiled lists of testing requirements are generally unavailable or incomplete. All states test for congenital hypothyroidism and phenylketonuria. Some states require that newborns be tested for up to six other specific congenital and inherited disorders of metabolism. Some states base their decision to test on demographic data, but there is no uniformity in the tests.