摘要:

AbstractRestricted T cell receptor (TCR) VB gene usage by T cells for recognition of antigens involved in the production of experimental autoimmune encephalomyelitis (EAE) offers the possibility of selective immunotherapy. We determined the preferential VB gene usage of lymph node‐derived clones from SJL/J mice to recognize the encephalitogenic epitope PLP 139‐151 and from PL/J mice to recognize the newly described encephalitogenic epitope PLP 43‐64. In addition, the VB gene usage for recognition of PLP 139‐151 by T cell lines derived from SJL/J spinal cords was analyzed. Lymph node‐derived SJL/J lines and clones specific for PLP 139‐151 expressed VB2, VB4, and VB17a preferentially, and PL/J lines and clones specific for PLP 43‐64 expressed VB2 and VB8.2 preferentially. A VB4+ SJL/J clone and a VB8.2+ PL/J clone were encephalitogenic. Encephalitogenic SJL/J lines derived from spinal cord expressed VB2, VB10, VB16, and VB17a preferentially, with a predominance of VB2. Candidate TCR peptides were synthesized and tested from the VB gene families VB4, VB8.2, and VB17a, based on our data and previous data on BP‐induced EAE in mice. Treatment of relapsing EAE (R‐EAE) in SJL/J mice with VB4 and VB17a peptides reduced clinical and histological disease severity, and treatment of R‐EAE in (PLxSJL)F1 mice with VB4 and VB8.2 peptides also reduced clinical and histological disease. The use of TCR peptide therapy may have applications for the treatment of human autoimmune diseases such as multiple sclerosis. ©

ISSN:0360-4012    

DOI:10.1002/jnr.490350202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractAn immortalized clonal cell line (AP‐16) has been established from glial cultures obtained from neonatal mouse cerebra by multipassages under serum‐free conditions. Immunofluorescent experiments showed that AP‐16 cells expressed a marker for glial progenitors (A2B5) and did not express markers for oligodendrocytes (galactocerebroside) or mature astrocytes (glial fibrillary acidic protein: GFAP). Treatment with transforming growth factor‐β1 (TGF‐β1) or fetal calf serum (FCS) for 2 days induced AP‐16 cells to differentiate into A2B5‐negative, GFAP‐positive, phenotypically mature astrocytes. AP‐16 cells depended on epidermal growth factor for survival, and their growth was inhibited by FCS. These results indicate that AP‐16 cells retained the properties of astrocyte progenitors. An enzyme‐linked immunosorbent assay showed that AP‐16 cells synthesized fibronectin and laminin, and that the expression of fibronectin was increased by TGF‐β1. AP‐16 cells should be useful for studying the roles of TGF‐β1 in the differentiation of astrocyte pr

ISSN:0360-4012    

DOI:10.1002/jnr.490350203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractWe analyzed cis‐acting elements regulating the expression of the gene encoding adhesion molecule on glia (AMOG) in primary cultured astrocytes from newborn rat cerebrum and cerebellum. The relative promoter activities among the series of 5‐ sequential deletion mutants are similar to those observed in B103 (rat neuroblastoma cell line) cells. The previously identified AMRE (AMOG regulatory element) of the GAGGCGGGG sequence functions as a positive regulatory element, not only in B103 cells, but also in astrocytes. Binding factors to the element were identified as Sp1 based on the following observations using nuclear extracts from the astrocytes and B103 cells: (1) The interaction of the factors with AMRE analyzed by DNase I footprinting and methylation interference analyses was similar to that of Sp1; (2) The binding of the factors to AMRE competed with an oligonucleotide containing the authentic Sp1 consensus sequence; (3) Sp1‐specific antibody interfered with the formation of the AMRE gel retardation complexes. The functional implications of the factors in AMOG gene regulation are discussed. © 1993 Wiley‐L

ISSN:0360-4012    

DOI:10.1002/jnr.490350204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe influence of accessory cells on the generation of neurons and neuronal survival has been studied in vitro using an immortalised, cloned cell line, Ast‐1, which has many of the functional and phenotypic characteristics of cells of the astrocytic lineage. It was found that monolayers of Ast‐1 cells were equivalent to monolayers of primary astrocytes in their ability to promote the generation of neurofilament positive neurons from neuroepithelial cells obtained from embryonic day 10 (E10) mice; and both were superior to NIH 3T3 cells. Ast‐1 cell monolayers were also found to provide a suitable substrate for the prolonged survival (at least 3 days in vitro) of neurofilament positive neurons obtained from E17 mice, whereas neurons plated onto NIH 3T3 cells were all dead after 2 days. Medium conditioned by Ast‐1 cells displayed similar biological activities to that of the monolayers: It increased the number of neurons generated from the E10 neuroepithelial cells, whether they were plated directly onto glass coverslips or onto monolayers of NIH 3T3 cells; and it increased the survival of E17 neurons plated directly onto glass coverslips. In addition, the Ast‐1 conditioned medium was shown to promote the survival of the neuroepithelial cells. These results confirm that one of the mechanisms by which astrocytes or their precursors may regulate neuronal development is by secreting soluble growth factors, as has been previously documented in the case of fibroblast growth factor (FGF) (Hatten et al., 1988; Drago et al., 1991a). However, it appears in this system that FGF is not responsible for the demonstrated biological activities, and the Ast‐1 action appears to be mediated by putatively novel factor(s). © 1993 Wil

ISSN:0360-4012    

DOI:10.1002/jnr.490350205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractNeurons in the central nervous system regenerate poorly or not at all. In contrast neurons of the peripheral nervous system have the ability to regrow their nerve fibers over considerable distances. Previously it has been suggested that the absence of the reinduction of the expression of growth associated proteins such as B‐50 (GAP43) may be an important factor in the differential response of CNS and PNS neurons to injury. We studied B‐50(GAP43) mRNA expression following lesioning of a class of CNS neurons, the olfactory bulb mitral cells. Expression of B‐50 mRNA in approximately 40% of the mitral cells was upregulated in response to transection of their axons in the lateral olfactory tract (LOT). Enhanced expression persisted for 10 days postlesion but had virtually declined to control levels by 4 weeks after the lesion. A large proportion of the mitral cells gradually degenerated subsequent to LOT transection. Thus a subpopulation of mitral cells maintains their ability to upregulate B‐50, a protein characteristic of growing axons, but enhanced B‐50 expression is not accompanied by regeneration of the severed LOT. © 1993 Wiley

ISSN:0360-4012    

DOI:10.1002/jnr.490350206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractMethylamine‐modified alpha‐2‐macroglobulin (MA‐α2M) has been recently shown to inhibit the biological activity of β‐nerve growth factor (NGF) in promoting neurite outgrowth by embryonic dorsal root ganglia in culture (Koo PH, Liebl DJ, J Neurosci Res 31:678–692, 1992). The objectives of this study are to determine whether α2M can also be modified by larger aromatic biogenic amines such as 5‐hydroxytryptamine (5HT; serotonin), the nature of interaction between NGF and 5HT‐modified alpha‐2‐M (5HT‐α2M), and the effect of 5HT‐α2M on the neurite extension and the growth of embryonic sensory and cholinergic neurons in 2 disparate animal species (chicken and rats). This study demonstrates that each mole of α2M can combine with 15.2 ± 1.8 moles of 5HT, in which up to 4.5 ± 0.4 moles may be covalently bonded. As determined by gel filtration and polyacrylamide gel electrophoresis studies, both 5HT‐α2M and normal α2M combine noncovalently with NGF, but 5HT‐α2M by comparison can combine with NGF somewhat more effectively. In contrast to normal α2M, 5HT‐α2M at concentrations greater than about 0.17 μM exerts a dose‐dependent inhibition on the NGF‐stimulated neurite outgrowth by embryonic dorsal root ganglia and dissociated cells in culture, and the inhibitory effect can be overcome by higher NGF concentrations. Both 5HT‐α2M and MA‐α2M at 1.0 μM inhibit neurite extension by embryonic rat cerebral cortical cells and seriously damage these cells in culture. Such neurite‐inhibitory activity, however, can only be partially blocked by extraneously added NGF alone. Normal α2M (at 1.0 μM) and 5HT (at 188 μM), on the other hand, under the identical conditions produce very little or no effect on the normal cellular and axonal growth of these cells. We conclude that α2M can potentially interact with nucleophilic monoamines, including neurotransmitters, to form inhibitory complexes which may inhibit/regulate NGF‐promoted neurite outgrowth and neuronal survival. In addition, higher concentrations of such complexes can seriously damage certain CNS neurons which do

ISSN:0360-4012    

DOI:10.1002/jnr.490350207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractA technique for isolation of adult Schwann cells (ScC) from dorsal root ganglia (DRG) is described. Decapsulated DRG explants embedded into type I collagen gels were cultured for 3 days in serum‐free medium during which ScC migrated from the explant. These explants were then grown in serum‐supplemented medium to allow ScC proliferation. On day 10 the number of ScC isolated from DRG explants per mouse was about 2.5 × 105, and the purity was greater than 95%. This culture system provided sufficient numbers of highly purified adult ScC in a shorter culture period (2–3 times) than other methods. We used ScC from this method to determine the age‐related changes in attachment, growth, and survival of ScC cultured in serum‐free medium. The attachment capacity of adult ScC on type I collagen or polylysine was similar to that of newborn ScC. However, the collagen promoted growth and survival of adult ScC but not that of neonatal ScC, indicating age‐related differences of ScC properties in vitro. © 1993 Wi

ISSN:0360-4012    

DOI:10.1002/jnr.490350208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe cholinergic system takes part in the immune‐neuroendocrine interation. Lymphocytes have been found to express muscarinic and nicotinic cholinergic receptors, as well as acetylcholine‐esterase on their surface, and cholinergic agents modulate immune functions in vitro and in vivo. In the present study we provide evidence that purified organ resident and circulating lymphocytes, as well as various lymphoid cell lines derived from different species, exhibit choline‐acetyltransferase activity and, therefore, have the potential to produce the neurotransmitter acetylcholine. © 1993 Wiley‐L

ISSN:0360-4012    

DOI:10.1002/jnr.490350209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractHydroxylamine (0.01–30 mM), a nitric oxide (NO) generator, produced a concentration‐dependent release of [3H]dopamine ([3H]DA) from rat striatal slices. Hemoglobin (10 μM), a NO scavenger, reduced basal [3H]DA release and blocked hydroxylamine (100 μM)‐stimulated [3H]DA efflux. Tetrodotoxin (0.5 μM) had no significant effect. Sodium cyanide was used as a model compound to test the possibility that NO acted through blockade of mitochondrial electron transport. Calcium‐free experimental buffer (1 mM EGTA) reduced basal release and the hydroxylamine response, while sodium cyanide‐induced release did not change under these experimental conditions. Cadmium (200 μM), a non‐selective inhibitor of voltage‐dependent calcium channels, reduced the hydroxylamine response by 69%. Methylene blue (10 μM), an inhibitor of guanylate cyclase, produced a 3‐fold increase in the basal release but had no significant effect on the hydroxylamine response. These data suggest that NO induces calcium‐dependent [3H]DA release from the striatum via a mechanism which is independent of blockade of electron transport or activation of guanylate cyclase.

ISSN:0360-4012    

DOI:10.1002/jnr.490350210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractIn vitro binding autoradiography was used to examine the pattern and intensity of binding of [3H]glutamate to NMDA receptors, [3H]MK 801 to NMDA receptor associated channels in and [3H]PN‐200 110 to L‐type calcium channels in the hippocampus of mice aged 3–70 days. The distribution of NMDA receptors and NMDA receptor associated channels was similar but not identical at the tested ages. Beginning with postnatal day 8, high binding levels were confined mostly to the hippocampal strata: the oriens and radiatum (CA1 and CA3 with [3H]MK 801 labeling but only CA1 with NMDA displaced [3H]glutamate labeling), the moleculare (higher labeling with [3H]MK 801 than with NMDA displaced [3H]glutamate binding), and the lucidum. The binding values for NMDA receptor‐channel complex rose in the examined period (especially within the second and third week), reaching a plateau at the end of the third postnatal week. Sharp growth of binding within the second and third week of life was about 50% greater with [3H]MK 801 than with NMDA displaced [3H]glutamate labeling. L‐type calcium channels were found to be most abundant in the strata: the oriens of the CA3 field, the moleculare, and the lucidum. The time course of binding value changes for the calcium channel was similar to the time course found for the NMDA receptor‐channel complex. © 1993 Wil

ISSN:0360-4012    

DOI:10.1002/jnr.490350211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY