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V Folsom

Publications and source records attributed to V Folsom.

11 recordsLinked to original sources
PubMed1993

The impact of sexual and physical abuse on eating disordered and psychiatric symptoms: a comparison of eating disordered and psychiatric inpatients.

The authors compared rates of physical and sexual abuse in women with eating disorders (N = 102) and general psychiatric disorders (N = 49). Relationships between sexual abuse and severity of eating disordered and psychiatric symptoms were also examined. While high rates of sexual abuse were found in the eating disordered sample, these rates were not significantly higher than those found in the general psychiatric population. No relationship between a history of sexual abuse and severity of eating disordered symptoms was found. However, within the eating disordered group, sexually abuse subjects reported more severe psychiatric disturbances of an obsessive and phobic nature than nonabused subjects. These findings suggest that while sexually abusive experiences may be related to increased psychological distress, they do not serve to increase eating disordered symptomatology.

Adolescent↗
PubMed1991

Upstream elements of the MHC class II E beta gene active in B cells.

The MHC class II (Ia) molecules are heterodimeric cell surface glycoproteins that have a limited tissue distribution and are essential for an Ir. These proteins are known to both display a limited tissue distribution and be responsive to up-regulation by cytokines such as IL-4. To begin to identify the molecular basis for both of these phenomena in B cells, we performed a deletional analysis of the upstream region of the murine E beta gene. We show that there are several cooperating positive as well as negative control elements in the E beta upstream region. The sequence between -2679 and -66 is a strong transcriptional element containing several sequences that act synergistically as positive elements. The negative elements are located more proximal to the transcription start site. Furthermore, two consensus motifs, termed X and Y, which are located in the proximal upstream region of all class II genes, are necessary for the transcriptional activity of more distal elements. Additionally, we identify an IL-4-responsive element located within 666 bp upstream of the transcription initiation site.

Animals↗
PubMed1990

Interferon gamma regulates binding of two nuclear protein complexes in a macrophage cell line.

Interferon gamma (IFN-gamma) is a potent inducer of major histocompatibility complex (MHC) antigens during normal immune responses and in abnormal responses in autoimmune disease. In this report we identify two nuclear factors whose binding to the murine E beta class II MHC beta-chain gene is regulated by this cytokine. IFN-gamma stimulation of murine macrophages results in the appearance of increased binding of one protein complex, complex A, and decreased binding of a second, faster migrating protein complex, complex B. Although the contact residues for both of these proteins lie within the highly conserved Y-box transcriptional element, their binding specificity differs. The protein in complex B is a CCAAT-box-binding protein that may be similar or identical to NF-Y or YB1, previously identified class II Y-box-binding proteins. The DNA sequence requirements for the binding of the slower migrating complex, complex A, are not limited to CCAAT-box sequences but include sequences upstream of the Y box. These upstream sequences are required both for IFN-gamma-induced gene transcription and for IFN-gamma-induced modulation of binding activity. These data suggest a model in which upstream sequences contribute to formation of a lymphokine-regulated complex downstream. The IFN-gamma-induced binding protein described as complex A in this report differs from the IFN-gamma, -alpha, or -beta-induced nuclear factors previously identified.

Animals↗
PubMed1989

Detection of DNA targets with biotinylated and fluoresceinated RNA probes. Effects of the extent of derivitization on detection sensitivity.

The substituted nucleotide aminohexyl-ATP (AH-ATP) was used for synthesis of RNA probes from a plasmid template using the T7 phage promoter. Following synthesis, RNA probes were modified by reaction with N-hydroxysuccinimide (NHS) esters of biotin or fluorescein. Nearest-neighbor analysis was used to quantitate both the incorporation of the substituted nucleotide into RNA and the subsequent modification of the incorporated nucleotide by the NHS esters. The results indicate that AH-ATP is efficiently incorporated into RNA and that modification of the amine group is also efficient. The T7 polymerase shows a bias for ATP over AH-ATP and truncated transcripts are produced if 100% AH-ATP is used for synthesis. However, the use of 50% AH-ATP in the synthesis reaction yields full-length RNA probes that contain on average one amine-labeled nucleotide every 12 bases. This RNA is readily modified by the respective NHS esters to obtain one biotin group per 15-18 total RNA bases or one fluorescein group per 25-35 bases. Probes modified with biotin or fluorescein were used to detect picogram levels of target DNA in a dot blot hybridization format.

Adenosine Monophosphate↗
PubMed1985

The beta 1 domain of the mouse E beta chain is important for restricted antigen presentation to helper T-cell hybridomas.

We have constructed a hybrid E beta gene by replacing the second exon of the Ed beta gene (which encodes the majority of the beta 1 protein domain) with the corresponding exon from the Eb beta gene. The hybrid gene has been introduced into a d haplotype host, the lymphoma beta-cell line A20-2J, and an E alpha E beta dimer composed of the endogenous Ed alpha chain and the product of the hybrid Ed beta/Eb beta gene was immunoprecipitated from extracts of transfected cells with an Ed alpha Eb beta-specific monoclonal antibody. Transfected cells have acquired the ability to present antigen to Ed alpha Eb beta-restricted helper T-cell hybridomas, indicating that the second exon of the gene for the E beta chain encodes sequences required for the restricted recognition of the antigen-presenting cell by the class II-restricted responder T-cell.

Animals↗
PubMed1984

Functional and inducible expression of a transfected murine class II major histocompatibility complex gene.

Using the spheroplast fusion technique, we have introduced the cloned E beta b gene into two d haplotype cell lines, the B lymphoma line A20-2J and the macrophage tumor line P388D1. Analysis with a monoclonal antibody indicates that the product of the transfected E beta b gene associates with the endogenous E alpha chain to form an E alpha dE beta b complex. While expression of E alpha dE beta b is constitutive in A20-2J cells transfected with the E beta b gene, surface expression of E alpha dE beta b is detected in transfected macrophage cells only after treatment of cells with culture supernatants from concanavalin A (Con A)-stimulated T cells. Transfected B lymphoma cells and transfected Con A supernatant-treated macrophage cells have acquired the ability to present antigen to E alpha dE beta b-restricted T-cell hybridomas. The observed inducible expression of the transfected gene in the macrophage host indicates that sequences responsible for regulated expression of the E beta b gene may be associated with the transfected gene. In combination with directed mutagenesis, the system described here provides a means to study (i) E beta b sequences that are important in determining the restriction specificity of the E molecule and (ii) sequences associated with the E beta gene that may be important in the regulation of E beta chain expression.

Alleles↗
PubMed1983

DNase I-hypersensitive sites in the chromatin of immunoglobulin kappa light chain genes.

We have used DNase I as a probe to examine the chromatin structure of mouse immunoglobulin kappa light chain genes in rearranged and unrearranged chromosomes--i.e., in nuclei from myeloma cells and from brain and liver cells. Tissue-specific DNase I-hypersensitive sites are observed 0.7 and 1.7 kilobases upstream from the 5' end of the C kappa gene in the J kappa -C kappa intron region in myeloma nuclei but not in naked DNA or in brain or liver nuclei. In myeloma cells expressing one functional kappa light chain polypeptide, but with more than one rearranged allele, one DNase I-hypersensitive site is found 0.3 kilobases upstream from the start of the coding region of the V kappa sequence in both functionally rearranged and nonfunctionally rearranged alleles but not in cross-hybridizing V kappa genes in the germ line context. Thus, during the development of B lymphocytes, the commitment of immunoglobulin kappa light chain gene expression seems to be associated with the presence of DNase I hypersensitivities that reflect changes of chromosomal structure surrounding the single copy C kappa gene. In contrast, the germ line V kappa multigene family seems to be located in a chromosomal region that does not exhibit change of DNase I hypersensitivity in response to commitment of immunoglobulin expression; a V kappa gene acquires DNase I hypersensitivity only after it is translocated adjacent to the J kappa -C kappa intron region. The DNase I-hypersensitive site 5' to the V kappa sequence is similar in location to hypersensitive sites found for other eukaryotic genes and is probably associated with the promoter region. However, the DNase I-hypersensitive sites in the J kappa -C kappa intron region are not associated with any known promoters. In addition, the DNA sequences surrounding the C kappa-proximal DNase I-hypersensitive site have several stretches of homology with sequences within the 72-base-pair tandem repeat of simian virus 40, which has been shown to modulate the transcriptional activity of neighboring genes. This DNase I-hypersensitive site in the intron region may be significant for the differential expression of the translocated V kappa genes.

Alleles↗
PubMedDate not supplied

Cell type-specific enhancer element associated with a mouse MHC gene, E beta.

Class II molecules of the major histocompatibility complex (MHC) are heterodimeric glycoproteins expressed on the surface of antigen-presenting B lymphocytes and macrophages. The genes encoding the alpha- and beta-chains of the class II heterodimers, A alpha A beta and E alpha E beta, have recently been characterized at the molecular level, and certain cloned genes were shown to be functionally expressed after introduction into cells by DNA-mediated gene transfer. One study found that a transfected Eb beta gene was expressed in a macrophage cell only after treatment of cells with gamma-interferon. DNA sequences associated with transfected Class II MHC genes may therefore have a regulatory role in their cell type-specific expression. We report here the identification of a cell type-specific transcriptional enhancer element associated with the mouse Ed beta gene.

Amino Acid Sequence↗
PubMedDate not supplied

Functional expression of a microinjected Ed alpha gene in C57BL/6 transgenic mice.

The class II major histocompatibility antigens, I-A and I-E, have been detected on the surface of certain immunocompetent cells, including B lymphocytes and monocytes. These molecules are involved in cell-cell interactions in the immune responses. Each class II antigen consists of two subunits, alpha and beta chains, and the genes encoding these subunits have been well characterized at the molecular level. To analyse the regulatory mechanism of E alpha gene expression and the role of the I-E antigen in the regulation of the immune responses, we have produced transgenic mice by microinjecting cloned Ed alpha genes into fertilized eggs of C57BL/6 mice of b haplotype. This strain of mouse carries a deletion in the upstream (5') region of the E alpha gene covering the transcriptional promoter and, therefore, does not express this gene. Interestingly, this genetic defect of the E alpha gene is accompanied by the inability of the host mouse to respond to a certain set of antigens, phenomena generally termed Ir gene control. We report here that the Ed alpha genes are expressed in these transgenic mice to form the I-Ed alpha Eb beta antigen on the surface of B lymphocytes and monocytes and that these I-E antigens are functional in terms of the induction of a mixed lymphocyte reaction and the restoration of immune responsiveness to poly(L-glutamic acid-L-lysine-L-phenylalanine) (GL-Phe).

Animals↗
PubMedDate not supplied

Unusual organization and diversity of T-cell receptor alpha-chain genes.

T lymphocytes recognize cell-bound antigens in the molecular context of the self major histocompatibility complex (MHC) gene products through the surface T-cell receptor(s). The minimal component of the T-cell receptor is a heterodimer composed of alpha and beta subunits, each of relative molecular mass (Mr) approximately 45,000 (refs 1-3). Recently, complementary DNA clones encoding these subunits have been isolated and characterized along with that of a third subunit of unknown function, termed gamma (refs 4-9). These studies revealed a primary structure for each subunit that was clearly similar to that of immunoglobulin and indicated a somatic rearrangement of corresponding genes that are also immunoglobulin-like. Recently, the analysis of the sequence organization of the T-cell receptor beta-chain and T-cell-specific gamma-chain gene families has been reported. We now present an initial characterization of the murine T-cell receptor alpha-chain gene family, and conclude that although it is clearly related to the gene families encoding immunoglobulins, T-cell receptor beta-chains and also T-cell gamma-chains, it shows unique characteristics. There is only a single constant (C) region gene segment, which is an exceptionally large distance (approximately 20-40 kilobases (kb) in the cases studied here) from joining (J) gene segments. In addition, the J cluster and the variable (V) segment number seen to be very large. Finally, in the case studied here, a complete alpha-chain gene shows no somatic mutation and can be assembled directly from V alpha, J alpha and C alpha segments without inclusion of diversity (D alpha) segments.

Animals↗