Failure to identify alveolar echinococcosis in trappers from South Dakota in spite of high prevalence of Echinococcus multilocularis in wild canids

Echinococcus multilocularis causes a rare but potentially lethal zoonotic disease in humans. This tapeworm has been known to be endemic in foxes (Vulpes vulpes) and coyotes (Canis latrans) within the northern United States since the 1960s. One purpose of this study was to provide recent data on the prevalence of E. multilocularis in foxes and coyotes from eastern South Dakota. In a survey conducted from 1987 to 1991 and involving 137 foxes and 9 coyotes from this area, 74.5% of the foxes and 4 of the coyotes were infected. To assess the possible prevalence of alveolar echinococcosis in a group at presumptive high risk, we also conducted a serological survey of members of the South Dakota Trappers Association in 1990 and 1991. Serum samples from 115 trappers were evaluated for the presence of E. multilocularis antibodies using enzyme-linked immunosorbent assay tests involving a purified antigen called Em2, a crude E. multilocularis antigen, and a recombinant E. multilocularis antigen called II/3-10. None of the trappers showed antibody evidence for the presence of E. multilocularis. Roughly half of the surveyed individuals had trapped more than 50 foxes during their life, and almost one-fourth had trapped more than 1,000 foxes.

Induction of interleukin-12/p40 by superantigens in macrophages is mediated by activation of nuclear factor-kappaB

Multimerization of the MHC class II molecule by superantigens results in activation of cellular signal transduction pathways in macrophage and B cells. Here we show that superantigen staphylococcal enterotoxin B (SEB) induces IL-12/p40 secretion in macrophages. SEB-induced expression of the IL-12/p40 gene involves activation and nuclear translocation of nuclear factor kappaB (NF-kappaB). The NF-kappaB heterodimer bound to the NF-kappaB consensus sequence of the IL-12/p40 gene promoter is p50/C-Rel. Inhibition of PKC and PKA activation results in suppression of activation and translocation of NF-kappaB. We conclude that signals for IL-12/p40 gene transcription from MHC class II molecules follow activation of PKC and PKA, which in turn leads to the activation and translocation of NF-kappaB to the nucleus. Our study suggests that superantigens are capable of influencing the nature of the immune response by regulating cytokine production. Induction of IL-12 production by superantigens may therefore play a role in the regulation of Th 1-mediated immune response and autoimmune disease.

Does Chlamydia pneumoniae play a role in the pathogenesis of multiple sclerosis?

It is proposed that the genome of human cytomegalovirus (HCMV) consists of two unique sequences, L and S, bounded by two sets of redundant sequences (P. Sheldrick et al. unpublished data). In this arrangement the terminal sequences (TR1 and TR8) are repeated in an intenal inverted form (IR1 and IR8) and delimit L and S. After restriction endonuclease cleavage of the DNA, four o.5 M and four 0.25 M fragments are found, indicating that HCMV DNA preparations consist of four equimolar populations differing only in the relative orientation of the L and S components. Cleavage of the CMV DNA with the restriction endonucleases BglII, HindIII and XbaI results in 32, 27 and 21 fragments, respectively. The arrangement of these fragments has been determined using molecular hybridization techniques, identification of terminal fragments and the identification of linkage groups by double-digestion. In this report the physical maps for the restriction endonucleases BglII, HindIII and XbaI are presented.

mCRY1 and mCRY2 are essential components of the negative limb of the circadian clock feedback loop

We determined that two mouse cryptochrome genes, mCry1 and mCry2, act in the negative limb of the clock feedback loop. In cell lines, mPER proteins (alone or in combination) have modest effects on their cellular location and ability to inhibit CLOCK:BMAL1 -mediated transcription. This suggested cryptochrome involvement in the negative limb of the feedback loop. Indeed, mCry1 and mCry2 RNA levels are reduced in the central and peripheral clocks of Clock/Clock mutant mice. mCRY1 and mCRY2 are nuclear proteins that interact with each of the mPER proteins, translocate each mPER protein from cytoplasm to nucleus, and are rhythmically expressed in the suprachiasmatic circadian clock. Luciferase reporter gene assays show that mCRY1 or mCRY2 alone abrogates CLOCK:BMAL1-E box-mediated transcription. The mPER and mCRY proteins appear to inhibit the transcriptional complex differentially.

Mucosal immunity in extrinsic allergic alveolitis: salivary immunoglobulins and antibody against inhaled avian antigens among pigeon breeders

BACKGROUND

Inhaled antigens from pigeons can cause extrinsic allergic alveolitis (EAA); a model disease of pulmonary inflammation. Among pigeon breeders, serum antibody and sensitized lymphocytes specific for these antigens have been described primarily, but not always, with disease. Antibody activity within the lung may have a closer association with disease, however, sampling by alveolar lavage at bronchoscopy is impractical for screening, therefore we used saliva to quantify the mucosal antibody response.

OBJECTIVE

To establish: (a) if antibody activity against inhaled avian antigens was detectable in the saliva of pigeon breeders, (b) if the distribution of saliva antibody and total immunoglobulin levels were quantitatively or qualitatively different from serum, and (c) whether the hypersensitivity symptoms of EAA were associated more with the mucosal or the systemic humoral immune response.

MEASURES

Saliva and serum total and avian antigen-specific IgG, IgA (IgA1 and IgA2) antibody activity in 87 pigeon breeders and 24 control subjects with no avian exposure. Albumin levels were used as a protein reference and cotinine levels confirmed smoking status. Specific hypersensitivity symptoms and various exposure indices to pigeons were established by interview.

RESULTS

Absolute levels and relative proportions (vs albumin) of IgG, IgA and IgA1 in saliva, and IgG in serum, were significantly higher in pigeon breeders compared with controls, suggesting mucosal inflammation. Avian antigen-specific antibody of all isotypes was readily demonstrable in saliva (predominantly IgA) and serum (predominantly IgG) from pigeon breeders, and there were no significant titres in controls. The levels of IgG antibody in saliva and in serum correlated significantly (r = 0.52, P < 0.001), and both correlated with the raised immunoglobulin levels. In both saliva and serum the IgG rather than the IgA antibody activity was associated with symptoms of EAA.

CONCLUSIONS

Antibody activity in saliva and serum, representing the mucosal and systemic responses, respectively, were both strongly stimulated by inhaled antigens. The IgG antibody titres of saliva and serum correlated significantly and were a useful index of inflammation, as measured by the raised total immunoglobulin levels, and symptoms. This suggests that IgG antibody in serum may reflect clinical and immunological sensitization of the lung mucosa. Collecting saliva is noninvasive, and saliva antibody measurement is a convenient method for monitoring EAA, especially in children, and will facilitate sampling for example in epidemiological studies of antibody prevalence.

Chlamydia pneumoniae infection of the central nervous system in multiple sclerosis

Our identification of Chlamydia pneumoniae in the cerebrospinal fluid (CSF) of a patient with multiple sclerosis (MS) led us to examine the incidence of this organism in the CSF from 17 patients with relapsing-remitting MS, 20 patients with progressive MS, and 27 patients with other neurological diseases (OND). CSF samples were examined for C pneumoniae by culture, polymerase chain reaction assays, and CSF immunoglobulin (Ig) reactivity with C pneumoniae elementary body antigens. C pneumoniae was isolated from CSF in 64% of MS patients versus 11% of OND controls. Polymerase chain reaction assays demonstrated the presence of C pneumoniae MOMP gene in the CSF of 97% of MS patients versus 18% of OND controls. Finally, 86% of MS patients had increased CSF antibodies to C pneumoniae elementary body antigens as shown by enzyme-linked immunosorbent assay absorbance values that were 3 SD greater than those seen in OND controls. The specificity of this antibody response was confirmed by western blot assays of the CSF, using elementary body antigens. Moreover, CSF isoelectric focusing followed by western blot assays revealed cationic antibodies against C pneumoniae. Infection of the central nervous system with C pneumoniae is a frequent occurrence in MS patients. Although the organism could represent the pathogenetic agent of MS, it may simply represent a secondary infection of damaged central nervous system tissue. A therapeutic trial directed at eliminating C pneumoniae from the central nervous system may provide additional information on its role in MS.

Sputum endothelin-1 is increased in cystic fibrosis and chronic obstructive pulmonary disease

Many patients with cystic fibrosis (CF) have airflow obstruction, with peribronchial and peribronchiolar fibrosis. Endothelin (ET)-1 is a potent bronchoconstrictor with mitogenic activity for airway smooth muscle. Do the levels of ET-1 in sputum support the putative role of ET-1 in contributing to airway remodelling with airflow obstruction in CF? The levels of ET-1 in plasma, saliva and sputum from 12 adult patients with CF not in exacerbation (spontaneous sputum), 17 normal control subjects (induced sputum) and as an additional control population, nine patients with stable chronic obstructive pulmonary disease (COPD) (seven spontaneous sputum) were measured. Total and differential sputum cell counts were performed. Median (interquartile range) sputum ET-1 level was elevated in CF (77.6 (29.0-122.8) pg x mL(-1)) compared to normal subjects (6.00 (2.8-14.8) pg x mL(-1)) and COPD (16.4 (6.8-38.2) pg x mL(-1)), and in COPD compared to normal subjects. There was a slight elevation of plasma ET-1 level in CF (5.3 (3.2-6.0) pg x mL(-1)) compared to normal subjects (3.1 (1.7-4.4) pg x mL(-1)) and COPD (3.3 (2.7-4.2) pg x mL(-1)). Sputum and saliva ET-1 levels were significantly higher than plasma levels in all groups, suggesting local production or release in the respiratory tract. Sputum differential cell counts revealed pronounced neutrophilia in CF and COPD compared to normal subjects. Sputum endothelin-1 concentrations are elevated in cystic fibrosis sputum compared to chronic obstructive pulmonary disease, and in cystic fibrosis and chronic obstructive pulmonary disease compared to normal subjects. The role of endothelin-1 in contributing to airflow obstruction through bronchoconstriction and mitogenesis in cystic fibrosis needs now to be explored.

Tyrphostin B42 inhibits IL-12-induced tyrosine phosphorylation and activation of Janus kinase-2 and prevents experimental allergic encephalomyelitis

IL-12 is a macrophage-derived cytokine that induces proliferation, cytokine production, and cytotoxic activity of T and NK cells. Signaling through its receptor, IL-12 induces these cellular responses by tyrosine phosphorylation and activation of Janus kinase-2 (Jak-2), Tyk-2, Stat3, and Stat4. We have used tyrphostin B42 (AG490), a Jak-2 inhibitor, to determine the role of Jak-2 kinase in IL-12 signaling and IL-12-induced T cell functions. Treatment of activated T cells with tyrphostin B42 inhibited the IL-12-induced tyrosine phosphorylation and activation of Jak-2 without affecting Tyk-2 kinase. In contrast, treatment with tyrphostin A1 inhibited the tyrosine phosphorylation of Tyk-2 but not that of Jak-2 kinase. Inhibition of either Jak-2 or Tyk-2 leads to a decrease in the IL-12-induced tyrosine phosphorylation of Stat3, but not of Stat4, protein. While inhibition of Jak-2 lead to programmed cell death, the inhibition of Jak-2 or Tyk-2 resulted a decrease in IFN-gamma production. We have further tested the in vivo effects of tyrphostin B42 in experimental allergic encephalomyelitis, a Th1 cell-mediated autoimmune disease. In vivo treatment with tyrphostin B42 decreased the proliferation and IFN-gamma production of neural Ag-specific T cells. Treatment of mice with tyrphostin B42 also reduced the incidence and severity of active and passive EAE. These results suggest that tyrphostin B42 prevents EAE by inhibiting IL-12 signaling and IL-12-mediated Th1 differentiation in vivo.

Superantigens augment antigen-specific Th1 responses by inducing IL-12 production in macrophages

Superantigens (SAg) are microbial proteins that mediate antigen-presenting cell (APC)-T cell interaction by cross-linking MHC class II molecules with subsets of TcRVbeta. SAgs are implicated in the pathogenesis of several infectious, inflammatory, and autoimmune diseases. In this study, we examined the influence of SEB on interleukin-12 (IL-12) production and the activation of antigen-specific Th1 responses. Addition of SEB augmented the antigen-induced proliferation of HS-17, a murine MBPp91-103 peptide-specific TcRVbeta6+ CD4+ Th1 clone. SEB augments HS-17 T cell proliferation through its interaction with IA(S) molecules on macrophages, but not with the TcRVbeta6 on HS-17 cells. On binding to IA(S), SEB induces IL-12 production in macrophages, which in turn augments antigen-induced proliferation of HS-17 T cells. Treatment with anti-IA(S) nmAb 10-3.6 inhibited the antigen- and SEB-induced IL-12 production and T cell proliferation. These results suggest that SAgs augment antigen-specific T cell responses by inducing IL-12 production in macrophages.

Differential influence of interleukin-12 in the pathogenesis of autoimmune and virus-induced central nervous system demyelination

Experimental allergic encephalomyelitis (EAE) and Theiler's murine encephalomyelitis virus (TMEV) disease are two demyelinating diseases of the central nervous system (CNS) that serve as animal models for multiple sclerosis. Th1 cells are thought to play a role in the pathogenesis of CNS demyelination in both these diseases. We show here the differential influence of interleukin 12, a critical cytokine for the development of Th1 cells in EAE and TMEV disease.

Prevention of experimental allergic encephalomyelitis via inhibition of IL-12 signaling and IL-12-mediated Th1 differentiation: an effect of the novel anti-inflammatory drug lisofylline

Experimental allergic encephalomyelitis (EAE) is an inflammatory, CD4+ Th1-mediated autoimmune disease, which serves as a model for multiple sclerosis. We examined the effect of a novel anti-inflammatory drug, lisofylline (LSF), on EAE induced either by injection of mouse spinal cord homogenate or following transfer of myelin basic protein-reactive T cells. Orally administered LSF significantly inhibited EAE in both cases, decreasing peak clinical scores by >70% and >80%, respectively. In addition, analysis of representative spinal cord sections from LSF-treated mice showed complete lack of demyelination and lymphocyte infiltration. The reduction in EAE correlated with the inhibition of Th1 differentiation by LSF in vivo, as indicated by a reduction in T cell IFN-gamma production ex vivo after Ag restimulation. The inhibition of Th1 differentiation in vivo is consistent with a block in IL-12 receptor signaling, because LSF blocked IL-12-driven Th1 differentiation and T cell proliferation in vitro, yet had no effect on IL-12 secretion from APCs ex vivo or in vitro.

The potential role of a late gene expression factor, lef2, from Bombyx mori nuclear polyhedrosis virus in very late gene transcription and DNA replication

Several late gene expression factors (Lefs) have been implicated in fostering high levels of transcription from the very late gene promoters of polyhedrin and p10 from baculoviruses. We cloned and characterized from Bombyx mori nuclear polyhedrosis virus a late gene expression factor (Bmlef2) that encodes a 209-amino-acid protein harboring a Cys-rich C-terminal domain. The temporal transcription profiles of lef2 revealed a 1.2-kb transcript in both delayed early and late periods after virus infection. Transcription start site mapping identified the presence of an aphidicolin-sensitive late transcript arising from a TAAG motif located at -352 nucleotides and an aphidicolin-insensitive early transcript originating from a TTGT motif located 35 nucleotides downstream to a TATA box at -312 nucleotides, with respect to the +1 ATG of lef2. BmLef2 trans-activated very late gene expression from both polyhedrin and p10 promoters in transient expression assays. Internal deletion of the Cys-rich domain from the C-terminal region abolished the transcriptional activation. Inactivation of Lef2 synthesis by antisense lef2 transcripts drastically reduced the very late gene transcription but showed little effect on the expression from immediate early promoter. Decrease in viral DNA synthesis and a reduction in virus titer were observed only when antisense lef2 was expressed under the immediate early (ie-1) promoter. Furthermore, the antisense experiments suggested that lef2 plays a direct role in very late gene transcription.

Relationship of cesarean delivery to lower birth weight-specific neonatal mortality in singleton breech infants in the United States

OBJECTIVE

The preferred route of delivery for breech presentation has been controversial. We compared the birth weight-specific neonatal mortality of vaginal births to cesarean births in singleton births with breech presentation.

METHODS

A total of 371,692 singleton live births with breech presentation were selected for the study from the United States birth cohorts for the years 1989-1991. Differences in birth weight specific mortality were compared using a z-statistic for differences in proportions and by logistic regression.

RESULTS

Compared to primary vaginal births, primary cesarean births had significantly lower neonatal mortality for all birth weight groups, despite increased prevalence of fetal malformations in the cesarean as compared with vaginally delivered group. This mortality difference was greatest in the first hour of life. Difference in overall neonatal (less than 28 days) mortality rate ranged from a low of 1.6-fold in the 500-749 g group (726.6 per 1000 vaginal births compared with 456.3 per 1000 cesarean births, P < .001) to as high as about three-fold in the 1250-1499 g group (232.9 per 1000 vaginal births compared to 72.5 per 1000 cesarean births, P < .001). In the group with birth weights over 2500 g, neonatal mortality in the primary vaginal births was 5.3 per 1000 and in the primary cesarean births, 3.2 per 1000 (P < .001). Similarly, repeat cesarean births had significantly lower birth weight-specific neonatal mortality, compared with vaginal births after previous cesarean.

CONCLUSION

Singleton live births with breech presentation delivered by cesarean had lower birth weight-specific neonatal mortality as compared with vaginal births.

TGF-beta inhibits IL-12-induced activation of Jak-STAT pathway in T lymphocytes

IL-12 is a macrophage-derived heterodimeric cytokine, capable of inducing proliferation, cytokine production, and cytotoxic activity of NK cells and T cells, and is critical for the development of Th1 responses. TGF-beta is an immunosuppressive cytokine that inhibits IL-12-mediated responses in NK and T cells. To determine the mechanism of action of TGF-beta, we examined its inhibitory effect on IL-12 signal-transduction pathway in T cells. Stimulation of activated T cells with IL-12 leads to tyrosine phosphorylation and activation of Jak-2 and Tyk-2 kinases and STAT3 and STAT4 transcription factors. Treatment of activated T cells with TGF-beta blocked IL-12-induced tyrosine phosphorylation and activation of both Jak-2 and Tyk-2 kinases. Furthermore, inhibition of Jak kinases by TGF-beta was associated with a decrease in tyrosine phosphorylation of STAT3 and STAT4 proteins. Abrogation of IL-12-induced Jak-Stat pathway by TGF-beta resulted in decreased T cell proliferation and IFN-gamma production, and increased apoptotic cell death. These findings highlight that TGF-beta inhibits IL-12-mediated responses by blocking IL-12 signal transduction in T cells.

Vasoactive intestinal peptide inhibits IL-12 and nitric oxide production in murine macrophages

Vasoactive intestinal peptide (VIP) is a naturally occurring neuropeptide widely distributed in the nervous system. In this study, we investigated the effect of VIP on IL-12, TNF alpha and nitric oxide (NO) production in macrophages following activation with lipopolysaccharide (LPS) or superantigens. In vitro studies show that at physiologic concentrations, VIP inhibited IL-12 and NO but not TNF alpha production in macrophages which were stimulated with LPS or superantigens. The inhibitory effect of VIP on IL-12 production appeared to be cAMP mediated since other cAMP inducing agents were also potent in inhibiting IL-12 production. Since IL-12 plays a critical role in T cell function, we suggest that naturally occurring neural hormones can regulate the type and direction of the immune response.

Mechanism of inhibition of LPS-induced IL-12p40 production by IL-10 and TGF-beta in ANA-1 cells

IL-12, a macrophage-derived proinflammatory cytokine, consists of two polypeptide subunits (p40 and p35) encoded by two separate genes. The p35 subunit is constitutively expressed, whereas the p40 subunit is induced after activation. The bioactive interleukin-12 (IL-12; p70) influences the development of Th1 responses and is a potent activator of natural killer (NK) and T cells. In contrast to IL-12, transforming growth factor beta (TGF-beta) and IL-10 inhibit production of proinflammatory cytokines, including IL-12, and attenuate Th1-mediated immune response. We have examined the molecular mechanisms by which TGF-beta and IL-10 inhibit production of the IL-12p40 subunit in LPS-stimulated murine macrophage cell line. We show that both IL-10 and TGF-beta suppress IL-12p40 production by inhibiting the transcription of IL-12p40 gene. At equal concentrations, IL-10 was more potent than TGF-beta in inhibiting IL-12p40 gene transcription. TGF-beta also reduces the stability of IL-12p40 mRNA, accounting thereby to an additional mechanism of inhibition of IL-12 production.

Expression of individual members of a tRNA(Gly)1 multigene family in vivo follows the same pattern as in vitro

Individual members of a tRNA(Gly)1 multigene family from Bombyx mori are transcribed to different levels in vitro in homologous nuclear extracts but their transcription status in vivo is not known. Two sets of tRNA(Gly)1 belonging to the extreme groups of highly transcribed and barely transcribed copies have been examined for their expression patterns in vivo in B. mori-derived cell lines following transfection. We have developed a sensitive and reliable method for directly quantifying the transcription levels of transfecting tRNA genes without relying on the biological activity of the transcript. The strategy involved the insertion of synthetic oligodeoxyribonucleotide sequences into the coding region of the transfecting gene and monitoring the transcripts in an RNase protection assay using an antisense probe that clearly distinguished them from the endogenous tRNAs. The oligonucleotide insertion did not significantly affect the transcriptional status of the genes, even though the distance between the A and B boxes was enhanced by 10-15 nt. In vivo also the transcription of tRNA(Gly)1 reached very high levels, whereas the transcripts arising from tRNA(Gly)1-6:7 accounted for only 2-5% of the former, closely resembling the transcription patterns in vitro. These individual gene copies having identical coding sequences and consequently the same internal conserved regions, differed only in their flanking sequences which modulate their transcription levels.

TGF-beta inhibits IL-2-induced tyrosine phosphorylation and activation of Jak-1 and Stat 5 in T lymphocytes

Signaling through IL-2R, IL-2 induces tyrosine phosphorylation and activation of Jak-1 and Jak-3 kinases and Stat 3 and Stat 5 transcription factors leading to cell cycle progression of activated T cells from G1 to S phase. TGF-beta is an immunosuppressive cytokine, which inhibits T cell proliferation at G1 to S phase transition. We examined the effect of TGF-beta on IL-2R signal transduction pathway in activated T cells. We show here that treatment of activated T cells with TGF-beta inhibited IL-2-induced tyrosine phosphorylation and activation of Jak-1 and Stat 5 but not Jak-3 and Stat 3. TGF-beta also inhibited IL-2-induced expression of alpha- and beta-chains of IL-2R and induced apoptotic cell death in T cells. These results suggest that TGF-beta-induced growth arrest and apoptosis are associated with the modulation of IL-2-induced activation of Jak-Stat pathway in T cells.

TGF-beta inhibits IL-2-induced tyrosine phosphorylation and activation of Jak-1 and Stat 5 in T lymphocytes

Signaling through IL-2R, IL-2 induces tyrosine phosphorylation and activation of Jak-1 and Jak-3 kinases and Stat 3 and Stat 5 transcription factors leading to cell cycle progression of activated T cells from G1 to S phase. TGF-beta is an immunosuppressive cytokine, which inhibits T cell proliferation at G1 to S phase transition. We examined the effect of TGF-beta on IL-2R signal transduction pathway in activated T cells. We show here that treatment of activated T cells with TGF-beta inhibited IL-2-induced tyrosine phosphorylation and activation of Jak-1 and Stat 5 but not Jak-3 and Stat 3. TGF-beta also inhibited IL-2-induced expression of alpha- and beta-chains of IL-2R and induced apoptotic cell death in T cells. These results suggest that TGF-beta-induced growth arrest and apoptosis are associated with the modulation of IL-2-induced activation of Jak-Stat pathway in T cells.

Successful treatment of established relapsing experimental autoimmune encephalomyelitis in mice with a monoclonal natural autoantibody

We postulated that humoral autoimmunity can play a beneficial role in CNS demyelinating diseases such as multiple sclerosis. We previously demonstrated that monoclonal natural autoantibody SCH94.03 suppresses CNS inflammation and promotes remyelination in a virus-induced model of chronic progressive multiple sclerosis. To further investigate the relationship between natural autoimmunity and CNS demyelination, we examined the effect of SCH94.03 treatment on clinical relapses and pathological disease in SJL/J mice with established adoptive-transfer relapsing experimental autoimmune encephalomyelitis. Treatment with SCH94.03 after recovery from the initial episode of clinical disease reduced relapse rates by half, prolonged relapse onset by 6 days and reduced spinal cord demyelination and meningeal inflammation by 40%. These results are consistent with the hypothesized immunomodulatory function of natural autoantibodies, and are the first direct demonstration that natural humoral autoimmunity can be beneficial in an autoimmune T-cell-mediated CNS demyelinating disease.

Heterologous promoter recognition leading to high-level expression of cloned foreign genes in Bombyx mori cell lines and larvae

The baculovirus expression system using the Autographa californica nuclear polyhedrosis virus (AcNPV) has been extensively utilized for high-level expression of cloned foreign genes, driven by the strong viral promoters of polyhedrin (polh) and p10 encoding genes. A parallel system using Bombyx mori nuclear polyhedrosis virus (BmNPV) is much less exploited because the choice and variety of BmNPV-based transfer vectors are limited. Using a transient expression assay, we have demonstrated here that the heterologous promoters of the very late genes polh and p10 from AcNPV function as efficiently in BmN cells as the BmNPV promoters. The location of the cloned foreign gene with respect to the promoter sequences was critical for achieving the highest levels of expression, following the order + 35 > + 1 > -3 > -8 nucleotides (nt) with respect to the polh or p10 start codons. We have successfully generated recombinant BmNPV harboring AcNPV promoters by homeologous recombination between AcNPV-based transfer vectors and BmNPV genomic DNA. Infection of BmN cell lines with recombinant BmNPV showed a temporal expression pattern, reaching very high levels in 60-72 h post infection. The recombinant BmNPV harboring the firefly luciferase-encoding gene under the control of AcNPV polh or p10 promoters, on infection of the silkworm larvae led to the synthesis of large quantities of luciferase. Such larvae emanated significant luminiscence instantaneously on administration of the substrate luciferin resulting in 'glowing silkworms'. The virus-infected larvae continued to glow for several hours and revealed the most abundant distribution of virus in the fat bodies. In larval expression also, the highest levels were achieved when the reporter gene was located at + 35 nt of the polh.

Anticandidal activity of Santolina chamaecyparissus volatile oil

A search for naturally occurring drugs with antifungal activity lead to Santolina oil, a volatile oil distillate of Santolina chamaecyparissus. The studies revealed that Santolina oil was effective in controlling experimental candidiasis in vitro and in vivo. It had a synergistic effect on clotrimazole in controlling Candida albicans in vitro. It significantly controlled experimental vaginal candidiasis and experimental systemic candidosis. Santolina oil was able to control the superficial cutaneous mycoses. It is recommended as a potential candidate for further studies, including clinical studies.

Regulation of microglial activation by TGF-beta, IL-10, and CSF-1

Microglia are the resident macrophages of the brain and as such are active participants in immune responses in the central nervous system. Normal resting microglia express low levels of MHC class I and class II antigens and do not produce proinflammatory cytokines. However, microglial immune functions are induced in areas of infection or injury. To understand regulation of cytokines that are secreted by and act upon microglia, we examined production of interleukin (IL) -12, tumor necrosis factor-alpha (TNF-alpha), and nitric oxide (NO) by lipopolysaccharide (LPS)-stimulated microglia. We observed secretion of IL-12, TNF-alpha, and NO following stimulation of microglia with LPS. Addition of IL-10 suppressed TNF-alpha, IL-12, and NO production. Transforming growth factor-beta (TGF-beta) also inhibited TNF-alpha and NO but did not affect IL-12 secretion. IL-12 secretion became sensitive to TGF-beta inhibition when microglia were cultured in the absence of CSF-1. In addition to its effect on the response to TGF-beta, CSF-1 suppressed the response of microglia to LPS. These data suggest that CSF-1 may contribute to the immunologically privileged status of the central nervous system.

Vaccination with peptides from MHC class II beta chain hypervariable region causes allele-specific suppression of EAE

In our earlier studies we showed that successful immunotherapy of EAE in SJL/J mice can be achieved either by the use of antibodies to MHC class II antigens or by vaccination with synthetic peptide analogs of the beta chain of MHC class II molecules. We proposed that inhibition of EAE following vaccination with synthetic peptides derived from the beta chain of mouse I-A, was in part due to the generation of auto-anti-MHC class II antibodies that interfered with T cell sensitization. In our present study we show that suppression of EAE following vaccination results in poor sensitization of MBP reactive T cells, and that the lack of immune response is allele-specific. In F1(SJL(I-AS) x Balb/cI-Ad) mice, in which susceptibility to EAE is linked closely to the I-AS allele, vaccination with peptides from beta chain of I-AS results in inhibition of proliferative response to MBP and prevents the development of EAE. Vaccination with peptide from the beta chain of I-Ad did not affect either the development of immune response to MBP or the induction of EAE, indicating allele-specific suppression. Since global immunosuppression is not induced by vaccination with I-A peptides, we propose that this strategy can be extended to human autoimmune diseases wherein a clear association between certain MHC class II alleles and autoimmune disease is evident.

Interferon-beta 1b treatment decreases tumor necrosis factor-alpha and increases interleukin-6 production in multiple sclerosis

MS is presumed to be a T-cell-mediated chronic inflammatory disease of the CNS. We examined proliferation and cytokine secretion of mononuclear cells after stimulation with OKT3 [anti-CD3] monoclonal antibody (MAb) or concanavalin A (Con A) in subjects with stable relapsing-remitting MS (RR MS) before and after initiating interferon (IFN)-beta 1b treatment. There was no significant difference in pretreatment to on-treatment anti-CD3 mAb or Con A-induced proliferation in RR MS patients. There was significantly increased Con A-induced secretion of tumor necrosis factor (TNF)-alpha, IFN-gamma, interleukin (IL)-2, IL-6, and IL-10 and decreased IL-4 secretion in on-treatment compared with pretreatment peripheral blood mononuclear cell samples. However, on-treatment CD3-mediated secretion of TNF-alpha was significantly decreased, and IL-6 secretion was significantly increased compared with pretreatment values. IFN-gamma was also decreased in on-treatment cultures stimulated with anti-CD3 MAb, but these values did not reach statistical significance. Systemic side effects from IFN-beta 1b were associated with increased IL-6 secretion. There were no significant changes in CD3-mediated IL-4, IL-10, transforming growth factor (TGF)-beta, or IL-2 secretion or Con A-induced TGF-beta secretion. IFN-beta 1b (Betaseron) decreases CD3-mediated TNF-alpha secretion but increases another inflammatory cytokine, IL-6, that could potentially counteract its beneficial immunomodulatory effects.

Soluble MHC II-peptide complexes induce antigen-specific apoptosis in T cells

Soluble major histocompatibility (MHC) class II molecules in association with antigenic peptide recognize T cell receptors (TCRs) on CD4+ T cells. Such recognition of MHC II-peptide complexes by T cells in the absence of costimulatory signals is known to induce T cell nonresponsiveness. The present study describes that recognition of TCRs by MHC class II-peptide complexes induces antigen-specific apoptosis in a T cell clone independently of nonresponsiveness. Apoptosis was demonstrated in a murine T cell clone (4R3.9) restricted for IAk in association with a peptide analog of myelin basic protein [MBP(1-14)A4]. A dose- and time-dependent T cell death was observed upon incubation of 4R3.9 T cells with purified IAk-MBP(1-14)A4 complexes. The specificity of T cell apoptosis was shown by incubating 4R3.9 T cells with irrelevant IAs-MBP(90-101) complexes. The DNA fragmentation as a result of apoptosis was demonstrated by agarose gel electrophoresis and by pulsing T cells with BrdU followed by the detection of BrdU-labeled DNA fragments using an antibody enzyme-linked immunosorbent assay. The expression level of two regulatory intracellular proteins, bcl-2 and bax, involved in apoptosis showed a decrease in bcl-2 and an increase in bax with time. Finally, the nuclear shrinkage and chromatin condensation, typical hallmark of apoptosis, have been demonstrated by transmission electron microscopy of complex-treated T cells. Since the T cell clone (4R3.9) used in this study failed to show nonresponsiveness by IAk-MBP(1-14)A4 complexes, our results suggest that apoptosis induced by purified MHC class II-peptide complexes may involve distinct pathways rather than T cell nonresponsiveness. Such antigen-specific apoptosis may have significant clinical relevance in deleting autoreactive T cells in various autoimmune diseases.

Frequency of MBP and MBP peptide-reactive T cells in the HPRT mutant T-cell population of MS patients

Somatic mutation as an index of in vivo T-cell amplification is a powerful tool to analyze the specificity and size of the autoreactive T-cell repertoire. Using this strategy, we determined the precursor frequency of T cells reactive to myelin basic protein (MBP) and overlapping MBP peptides spanning regions p84-168 in patients with MS and controls in the HPRT mutant T-cell population. Among 19 MS patients, nine had estimatable frequencies to MBP or MBP peptides, p93-112, p124-142 and p143-168 in the HPRT mutant T-cell population. Only one of the 10 controls showed measurable frequency to MBP in the HPRT mutant T-cell population. These studies suggest that increased frequency of T cells reactive to MBP and MBP peptides might indicate putative disease-related epitopes in MS.

Santolina volatile oil, a potential antifeedant for the control of the brown plant hopper, milaparvatha lugens

The essential oil of santolina chamaecyparissus reduced the survival of Nilaparvatha lugens after 72 hours. The oil is found to be a good pesticide.

Extraordinary-mode refractive-index change produced by the linear electro-optic effect in LiNbO(3) and reverse-poled LiNbO(3)

To examine aspects of an integrated photonic electric-field sensor, we calculate electro-optically induced refractive-index change in regular and reverse-poled LiNbO(3). Specifically, for y-propagating extraordinary modes, we determine how index change depends on electric-field magnitude and direction. To accomplish this, changes in index-ellipsoid shape and orientation are found by the use of a numerical eigenvalue procedure to diagonalize the impermeability tensor; then, refractive index is calculated by the use of a vector reference-frame transformation and a small perturbation approximation. A general formula is inferred from calculations for specific field directions. Electro-optic coefficients for reversepoled LiNbO(3) are obtained by application of a tensor reference-frame transformation to those of LiNbO(3). The index-calculation procedure has utility beyond the problem that is considered.

TGF-beta 2 decreases migration of lymphocytes in vitro and homing of cells into the central nervous system in vivo

Migration of leukocytes through an in vitro, cell culture model of the blood-brain barrier (BBB) composed of murine brain microvessel endothelial (En) cells and astrocytes, and in vivo in experimental allergic encephalomyelitis (EAE), was investigated. We have recently shown that the adhesiveness of cultured murine brain microvascular endothelial cells for lymphocytes can be increased significantly by pretreatment with IL-1 beta, TNF-alpha, IFN-gamma, and LPS. In the present study, we investigated the role of TGF-beta 2 on the migration of leukocytes through the BBB. In vitro migration was assessed by measuring the percentage of 51Cr-labeled leukocytes migrating through the En/astrocyte monolayers. The basal level of migration was up-regulated significantly by treating the En/astrocyte monolayers with IL-1 alpha, IFN-gamma, TNF-alpha, and LPS. The ability of these cytokines to modulate migration was dose-dependent. Treatment of En cell/astrocyte monolayers with TGF-beta 2 down-regulated the level of leukocyte migration up-regulated by IL-1 alpha, IFN-gamma, and TNF-alpha in vitro in a dose-dependent manner. TGF-beta 2 also inhibited the migration of lymphocytes into the central nervous system (CNS) in vivo in a dose-dependent fashion. Taken together, these findings strongly suggest that TGF-beta plays an important role in the reduction of lymphocyte infiltration into the CNS in inflammatory demyelinating diseases such as EAE.

TGF-beta 2 decreases migration of lymphocytes in vitro and homing of cells into the central nervous system in vivo

Migration of leukocytes through an in vitro, cell culture model of the blood-brain barrier (BBB) composed of murine brain microvessel endothelial (En) cells and astrocytes, and in vivo in experimental allergic encephalomyelitis (EAE), was investigated. We have recently shown that the adhesiveness of cultured murine brain microvascular endothelial cells for lymphocytes can be increased significantly by pretreatment with IL-1 beta, TNF-alpha, IFN-gamma, and LPS. In the present study, we investigated the role of TGF-beta 2 on the migration of leukocytes through the BBB. In vitro migration was assessed by measuring the percentage of 51Cr-labeled leukocytes migrating through the En/astrocyte monolayers. The basal level of migration was up-regulated significantly by treating the En/astrocyte monolayers with IL-1 alpha, IFN-gamma, TNF-alpha, and LPS. The ability of these cytokines to modulate migration was dose-dependent. Treatment of En cell/astrocyte monolayers with TGF-beta 2 down-regulated the level of leukocyte migration up-regulated by IL-1 alpha, IFN-gamma, and TNF-alpha in vitro in a dose-dependent manner. TGF-beta 2 also inhibited the migration of lymphocytes into the central nervous system (CNS) in vivo in a dose-dependent fashion. Taken together, these findings strongly suggest that TGF-beta plays an important role in the reduction of lymphocyte infiltration into the CNS in inflammatory demyelinating diseases such as EAE.

Decreased CD3-mediated interferon-gamma production in relapsing-remitting multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that has been postulated to be T-cell mediated. We examined the proliferation and cytokine secretion of mononuclear cells after stimulation with OKT3 (anti-CD3) monoclonal antibody concanavalin A, or ionomycin plus myristic acid palmityl ester in subjects with stable relapsing-remitting MS. Control subjects demonstrated good proliferation to anti-CD3 monoclonal antibody whereas subjects with relapsing-remitting MS showed a significantly decreased anti-CD3 monoclonal antibody-mediated response. There was no difference in concanavalin or ionomycin plus myristic acid palmityl ester stimulation between control subjects and MS subjects. Secretion of interferon-gamma was significantly decreased and transforming growth factor-beta was significantly increased from cultures stimulated with anti-CD3 monoclonal antibody, but not ionomycin plus myristic acid palmityl ester or concanavalin A, in MS patients compared to control subjects. Secretion of interleukin-10 and tumor necrosis factor-alpha was not different between control subjects and MS patients following stimulation with anti-CD3 monoclonal antibody, concanavalin A, or ionomycin plus myristic acid palmityl ester, or of interleukin-2 and interleukin-4 following stimulation with anti-CD3 monoclonal antibody or concanavalin A. An abnormality of signal transduction and secretion of the immunomodulatory molecule interferon-gamma may exist in MS via the CD3 T-cell receptor complex.

The immunology of multiple sclerosis and its animal model, experimental allergic encephalomyelitis

Two questions were posed at the beginning of this article. Is EAE a good model for MS? And, is MS an autoimmune disease? The first question is easier to address than the second. EAE is the best available model for the inflammatory processes that occur in MS, and for the disease process. The latter depends somewhat on study of chronic relapsing EAE, rather than early or mono-episodic EAE, which, although of great immunological interest, is of less relevance to the established disease that presents as MS. The second question asks whether MS fulfills Koch's postulates as an autoimmune disease. MS has all the hallmarks of an inflammatory disease of the CNS. The question then is whether the inflammation is autoimmune. The evidence presented shows a considerable autoimmune component to MS inflammation, raising the subsidiary question of whether autoimmune reactivity induces MS. This remains unanswerable for the present, and it should be kept in mind that the same question also would be unanswerable by observation of EAE. The major postulate therefore remains unfulfilled. Diagnosis of MS as an autoimmune disease requires definitive identification of the autoantigen; otherwise, the possibility remains open that this is a disease resulting from the inadvertent activation and dysregulation of immune processes in the CNS that, themselves, are not directed at that organ.

Myelin basic protein peptide specificity and T-cell receptor gene usage of HPRT mutant T-cell clones in patients with multiple sclerosis

Characterization of T cells responding to autoantigens is central to understanding autoimmune disease. We have used somatic mutation at the hypoxanthine guanine phosphoribosyltransferase (HPRT) gene as an index of T-cell amplification in vivo. With this strategy we previously showed that myelin basic protein-reactive T cells can be isolated only from the HPRT mutant T-cell population cultured from the peripheral blood of multiple sclerosis patients and not from normal individuals. In this study, 165 HPRT mutant and 104 wild-type clones were examined for their reactivity to myelin basic protein and overlapping peptides of myelin basic protein. Five HPRT mutant clones that recognized myelin basic protein and myelin basic protein peptides along with three clones that responded to myelin basic protein peptide alone were isolated. All but one of the eight clones recognized peptides derived from the carboxy terminus of myelin basic protein (p84-168). Sequence analysis showed heterogeneous expression of T-cell receptor V alpha and V beta genes and CDR3s. These studies showed that in vivo amplified autoimmune T cells from patients with long-standing disease use diverse T-cell receptor elements in the recognition of C-terminal myelin basic protein peptides.

A synthetic peptide from the third hypervariable region of major histocompatibility complex class II beta chain as a vaccine for treatment of experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a class II major histocompatibility complex (MHC)-restricted, T-cell-mediated, demyelinating autoimmune disease of the central nervous system and represents a model for human multiple sclerosis. The present study demonstrates that vaccination of SJL/J mice with an 18-amino acid synthetic peptide from the third hypervariable region of the murine class II MHC IAs beta chain (IAs beta 58-75; 18-mer peptide) is capable of eliciting auto-anti-IAs antibodies specific for the IAs beta chain and preventing and treating EAE. A similar approach may be useful in the treatment of human autoimmune diseases in which susceptibility is linked to class II MHC genes.

Homologies between T cell receptor junctional sequences unique to multiple sclerosis and T cells mediating experimental allergic encephalomyelitis

The selection of T cell clones with mutations in the hypoxanthine guanine phosphoribosyltransferase (hprt) gene has been used to isolate T cells reactive to myelin basic protein (MBP) in patients with multiple sclerosis (MS). These T cell clones are activated in vivo, and are not found in healthy individuals. The third complementarity determining regions (CDR3) of the T cell receptor (TCR) alpha and beta chains are the putative contact sites for peptide fragments of MBP bound in the groove of the HLA molecule. The TCR V gene usage and CDR3s of these MBP-reactive hprt-T cell clones are homologous to TCRs from other T cells relevant to MS, including T cells causing experimental allergic encephalomyelitis (EAE) and T cells found in brain lesions and in the cerebrospinal fluid (CSF) of MS patients. In vivo activated MBP-reactive T cells in MS patients may be critical in the pathogenesis of MS.

Longitudinal study of frequency of HPRT mutant T cells in patients with multiple sclerosis

Analysis of somatic mutation in circulating peripheral blood T cells can be used as an index of in vivo T-cell amplification. The ability to assess the frequency of T cells that survive in vitro in the presence of 6-thioguanine is an index of mutation at the HPRT gene locus. In the absence of exposure to mutational agents, elevations of the HPRT mutant frequency (mF) of T cells reflects errors in DNA replication and repair that have become fixed during the process of cell division. We estimated the mF of T cells in MS patients and controls over a period of 36 months and found that the mF was consistently elevated in MS patients of all clinical subgroups. In the chronic progressive group of MS, the mF increased over a 3-year period and appeared to correlate with the clinical worsening of the disease.

Lumbosacral radiculoplexopathy as a manifestation of Epstein-Barr virus infection

We report the clinical features of five patients with lumbosacral radiculoplexopathy (LSRP) and one patient with a femoral neuropathy, all of whom had serologic evidence of a recent Epstein-Barr virus (EBV) infection. After a thorough investigation, no other etiology was apparent. Pain was a prominent feature in all cases, and the prognosis was generally good, with recovery in weeks to months. We conclude that LSRP may occur as a postinfectious process following recent EBV infection.

Experimental allergic encephalomyelitis: neutralizing antibody to TGF beta 1 enhances the clinical severity of the disease

Experimental allergic encephalomyelitis (EAE) is a well established model for the human autoimmune disease multiple sclerosis. Recently, we and others have shown that the administration of TGF beta is therapeutically effective in reducing incidence and severity of EAE. Here we show that the addition of anti-TGF beta 1 to myelin basic protein (MBP)-activated lymph node cells enhance the T cell proliferative response by 28% in vitro and in vivo and that injections of anti-TGF beta 1 antibody worsen EAE both in incidence and severity. Further, an inverse relationship was observed in the amount of IL-2 and TGF beta detected in MBP stimulated culture supernatants. We show that IL-2 decreases from 248 U/ml at 48 h to non-detectable at 96 h, while TGF beta increases from 0.5 ng/ml to 1.2 ng/ml, respectively. These observations further indicate a role for endogenous TGF beta 1 in the immunoregulation of EAE.

Long-term treatment of chronic relapsing experimental allergic encephalomyelitis by transforming growth factor-beta 2

It had been demonstrated previously that the administration of transforming growth factor-beta 1 (TGF-beta 1) reduced the clinical severity of experimental allergic encephalomyelitis (EAE). Treatment with the related immunosuppressive molecule, TGF-beta 2, resulted in similar inhibition of T cell activation and proliferation in vitro. Long-term treatment was effective in reducing clinical severity of EAE and the number of relapses in mice receiving either myelin basic protein- or peptide-91-103-specific T cell lines. When examined histologically, mice that had received TGF-beta 2 demonstrated significantly less inflammation and demyelination in the central nervous system. Examination of other organs demonstrated no pathology or deleterious side effects from long-term TGF-beta 2 therapy. These findings have relevance for the use of TGF-beta 2 as a therapeutic agent for the human demyelinating disease, multiple sclerosis.

Transforming growth factor-beta 1 differentially regulates proliferation and MHC class-II antigen expression in forebrain and brainstem astrocyte primary cultures

To facilitate investigation of cytokine regulation of reactive astrogliosis, primary astrocyte cultures from neonatal murine forebrain and brainstem were established. Forebrain and brainstem astrocytes proliferated at a similar rate under basal culture conditions, and both were growth-inhibited by treatment with recombinant murine interferon-gamma. The growth of cultured brainstem astrocytes was significantly enhanced by exposure to recombinant human transforming growth factor-beta 1. In contrast, proliferation of forebrain astrocytes was not significantly affected by transforming growth factor-beta 1. The disparate responses of brainstem and forebrain astrocytes to transforming growth factor-beta 1 treatment were not limited to effects on cell growth, since transforming growth factor-beta 1 could block interferon-gamma-induced MHC class-II antigen expression on cultured brainstem astrocytes but not on forebrain cells. Results could not be attributed to use of an heterologous cytokine/cellular target system, since similar variability in transforming growth factor-beta 1 modulation of major histocompatibility complex antigen expression could be demonstrated using two human astrocytoma cell lines. This report is the first to document mitogenic response to transforming growth factor-beta 1 for neuroepithelial cells. The role of transforming growth factor-beta 1 in regulating aspects of reactive astrogliosis, particularly in the context of inflammatory demyelination, requires further investigation. Furthermore, these studies may provide insight into regional variability in the sequelae of inflammation within the central nervous system.

Analysis of TCR V beta gene usage and encephalitogenicity of myelin basic protein peptide p91-103 reactive T cell clones in SJL mice: lack of evidence for V gene hypothesis

We have analyzed the epitope specificity and encephalitogenicity of peptides that span the C terminus of MBP, p84-103. Our studies show that multiple antigenic epitopes with disease-inducing capacity exist in SJL mice. Three peptides that span this region were examined and found to be immunogenic. However, the mode of immunization (active or passive) determined the incidence and severity of EAE. In our experiments adoptive transfer of p91-103-reactive T cell lines was most consistent in the development of disease. Interestingly, the response to peptides p89-101, p91-103, and p84-102 was absent following immunization with MBP. This suggests that although p91-103 and p89-101 were encephalitogenic they were not the major immunogenic epitopes following immunization with MBP. Analysis of a panel of eight p91-103-reactive T cell clones showed significant heterogeneity in the fine specificity, the TCR V beta gene usage, and in their ability of transfer EAE. These studies suggest that in SJL mice the epitopes involved in the pathogenesis of disease are multiple and there is no clear correlation between encephalitogenicity and TCR V beta gene usage. These observations argue against the presence of a dominant TCR V beta gene in the pathogenesis of EAE in SJL mice.

Antigen-specific therapy of experimental allergic encephalomyelitis by soluble class II major histocompatibility complex-peptide complexes

Experimental allergic encephalomyelitis is a T-cell-mediated, major histocompatibility complex (MHC) class II gene-linked autoimmune demyelinating disease of the central nervous system. To develop therapies that will specifically inactivate only the autoantigen-reactive T cells, mice were treated with soluble MHC class II molecules that had been complexed with encephalitogenic peptides. Intravenous injections of 300 micrograms of complexes consisting of encephalitogenic peptide 91-103 of myelin basic protein plus I-As protein on day 0, 4, and 7 were effective in preventing experimental allergic encephalomyelitis. Similarly, administration of 45 micrograms of I-As protein complexed to peptide 139-151 from proteolipoprotein on day 1, 4, and 7 prevented mortality and significantly reduced paralysis induced by immunization with the encephalitogenic proteolipoprotein peptide. Histological examination of sections of animal brains revealed that treatment with I-As protein plus myelin basic protein 91-103 peptide prevents the development of inflammatory lesions characteristic of experimental allergic encephalomyelitis. Thus, treatment with MHC-self-peptide complexes could serve as a highly specific therapeutic modality in treating autoimmune disease when the putative autoantigen and the MHC restricting elements are known.