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L Cairns

Publications and source records attributed to L Cairns.

At least 19 recordsLinked to original sources
PubMed2000

Regulation of mouse p45 NF-E2 transcription by an erythroid-specific GATA-dependent intronic alternative promoter.

The erythroid-enriched transcription factor NF-E2 is composed of two subunits, p45 and p18, the former of which is mainly expressed in the hematopoietic system. We have isolated and characterized the mouse p45 NF-E2 gene; we show here that, similar to the human gene, the mouse gene has two alternative promoters, which are differentially active during development and in different hematopoietic cells. Transcripts from the distal promoter are present in both erythroid and myeloid cells; however, transcripts from an alternative proximal 1b promoter, lying in the first intron, are abundant in erythroid cells, but barely detectable in myeloid cells. During development, both transcripts are detectable in yolk sac, fetal liver, and bone marrow. Transfection experiments show that proximal promoter 1b has a strong activity in erythroid cells, which is completely dependent on the integrity of a palindromic GATA-1 binding site. In contrast, the distal promoter 1a is not active in this assay. When the promoter 1b is placed 3' to the promoter 1a and reporter gene, in an arrangement that resembles the natural one, it acts as an enhancer to stimulate the activity of the upstream promoter la.

Alternative Splicing↗
PubMed2000

Outbreak of coccidioidomycosis in Washington state residents returning from Mexico.

In July 1996 the Washington State Department of Health (Seattle) was notified of a cluster of a flulike, rash-associated illness in a 126-member church group, many of whom were adolescents. The group had recently returned from Tecate, Mexico, where members had assisted with construction projects at an orphanage. After 1 member was diagnosed with coccidioidomycosis, we initiated a study to identify further cases. We identified 21 serologically confirmed cases of coccidioidomycosis (minimum attack rate, 17%). Twenty cases (95%) occurred in adolescents, and 13 patients (62%) had rash. Sixteen symptomatic patients saw 19 health care providers; 1 health care provider correctly diagnosed coccidioidomycosis. Coccidioides immitis was isolated from soil samples from Tecate by use of the intraperitoneal mouse inoculation method. Trip organizers were unaware of the potential for C. immitis infection. Travelers visiting regions where C. immitis is endemic should be made aware of the risk of acquiring coccidioidomycosis, and health care providers should be familiar with coccidioidomycosis and its diagnosis.

Adolescent↗
PubMed1999

Intermediate filament interactions can be altered by HSP27 and alphaB-crystallin.

HSP27 and alphaB-crystallin are both members of the small heat shock protein family. alphaB-crystalllin has been proposed to modulate intermediate filaments and recently a mutation in alphaB-crystallin has been identified as the genetic basis of desmin related myopathy. This disease is characterised in its pathology by aggregates of intermediate filaments associated with alphaB-crystallin. Here we report that HSP27 like alphaB-crystallin is associated with glial fibrillary acidic protein and vimentin intermediate filament networks in unstressed U373MG astrocytoma cells. HSP27 is also associated with keratin filaments in MCF7 cells, indicating that this association is not restricted to a particular intermediate filament type. The association of sHSPs with both the soluble and filamentous intermediate filament fractions of U373 cells was demonstrated biochemically. Heat shock or drug treatments induced a co-collapse of intermediate filaments and associated small heat shock proteins. These data show that the presence of HSP27 or alphaB-crystallin could not prevent filament collapse and suggest that the purpose of this association is more than just filament binding. Indeed, in U373MG cells the intermediate filament association with small heat shock proteins is similar to that observed for another protein chaperone, HSC70. In order to discern the effect of different chaperone classes on intermediate filament network formation and maintenance, several in vitro assays were assessed. Of these, falling ball viscometry revealed a specific activity of small heat shock proteins compared to HSC70 that was apparently inactive in this assay. Intermediate filaments form a gel in the absence of small heat shock proteins. In contrast, inclusion of alphaB-crystallin or HSP27 prevented gel formation but not filament assembly. The transient transfection of GFAP into MCF7 cells was used to show that the induction of a completely separate network of intermediate filaments resulted in the specific association of the endogenous HSP27 with these new GFAP filaments. These data lead us to propose that one of the major functions of the association of small heat shock proteins with intermediate filaments is to help manage the interactions that occur between filaments in their cellular networks. This is achieved by protecting filaments against those non-covalent interactions that result when they come into very close proximity as seen from the viscosity experiments and which have the potential to induce intermediate filament aggregation as seen in some disease pathologies.

Cell Compartmentation↗
PubMed1997

Expression in hematopoietic cells of GATA-1 transcripts from the alternative "testis" promoter during development and cell differentiation.

GATA-1 is a transcription factor expressed both in the hematopoietic system and in the Sertoli cells of the testis, and is essential for correct erythropoiesis. Hematopoietic and Sertoli cells transcribe GATA-1 from two different promoters: the proximal (erythroid) is active in hematopoietic cells; the distal (testis) is active in Sertoli cells. We investigated by RT-PCR the possibility that GATA-1 might be transcribed from the testis promoter also in hematopoietic cells. Testis promoter-derived transcripts are present at low levels in vivo at all stages of hematopoietic development. Purified multipotent progenitors, fractionated into populations expressing low or high levels of GATA-1, do not contain any "testis" transcripts. However, when grown in vitro, they rapidly express GATA-1 from the testis promoter in the presence of Erythropoietin (Epo) but not in that of other growth factors. This result reflects an Epo-dependent differentiation event, rather than a direct effect of Epo. Indeed, immortalized progenitor cell lines which respond to both Epo and SCF, continue to express testis-derived transcripts when switched from Epo to SCF.

Alternative Splicing↗
PubMed1997

Molecular heterogeneity of regulatory elements of the mouse GATA-1 gene.

The GATA-1 gene encodes a transcription factor expressed in early multipotent haemopoietic progenitors, in more mature cells of the erythroid, megakaryocytic and other lineages, but not in late myeloid precursors; its function is essential for the normal development of the erythroid and megakaryocytic system. To define regulatory elements of the mouse GATA-1 gene, we mapped DNaseI-hypersensitive sites in nuclei of erythroid and haemopoietic progenitor cells. Five sites were detected. The two upstream sites, site 1 and site 2, represent a new and a previously defined erythroid enhancer respectively. The site 1 enhancer activity depends both on a GATA-binding site (also footprinted in vivo) and on several sites capable of binding relatively ubiquitous factors. A DNA fragment encompassing site 1, placed upstream of a GATA-1 minimal promoter, is able to drive expression of a simian virus 40 (SV40) T-antigen in the yolk sac, but not bone-marrow cells, obtained from mice transgenic for this construct, allowing in vitro establishment of immortalized yolk-sac cells. A similar construct including site 2, instead of site 1, and previously shown to be able to immortalize adult marrow cells is not significantly active in yolk-sac cells. Sites 4 and 5, located in the first large intron, have no enhancer activity; they include a long array of potential Ets-binding sites. MnlI restriction sites, overlapping some of the Ets sites, are highly accessible, in intact nuclei, to MnlI. Although these sites are present in all GATA-1-expressing cells studied, they are the only strong sites detectable in FDCP-mix multipotent progenitor cells, most of which do not yet express GATA-1. The data indicate that appropriate GATA-1 regulation may require the co-operation of different regulatory elements acting at different stages of development and cell differentiation.

Animals↗
PubMed1994

Retroviral immortalization of phagocytic and dendritic cell clones as a tool to investigate functional heterogeneity.

We have developed a method to generate immortalized phagocytic and dendritic cell clones from various mouse tissues such as spleen, thymus, brain and bone marrow. The clones were phenotypically characterized and shown to retain the ability to respond to immune or inflammatory signals, e.g., IFN-gamma. Functional cytokine activity and nitric oxide production were maintained in activated macrophages, microglial and dendritic cell clones. Immune functions, such as antigen presentation was exhibited by all clones whereas tissue-specific properties such as the ability to respond to corticotropin-releasing hormone and produce beta-endorphin was shown in microglial cell clones but not in macrophage cell clones, indicating that heterogeneity of cells of the mononuclear-phagocytic lineage can be maintained in vitro after the immortalization procedure. Moreover, the continuous proliferation of the clones could be inhibited by various stimuli and further differentiation of the cells could be achieved in vitro.

Animals↗
PubMed1993

The regulation of IgG4. 1. An immunoassay to detect bee venom specific IgG4 subclass levels.

Serum IgG consists of 4 subclasses designated IgG1-4. IgG subclasses have differing structures and different functions. The levels of antigen specific immunoglobulin in each of the subclasses is difficult to quantitate accurately but may be of significant diagnostic and therapeutic value. IgG4 constitutes approximately 4% of total IgG level in the serum. We describe an immunoassay which is highly sensitive and specific for IgG4 directed against bee venom. The assay can be performed in a routine diagnostic laboratory enhancing its value as a clinical tool. It is potentially useful in identifying patients who fail to respond to standard immunotherapy with bee venom. This immunoassay format can also be adapted to other antigens.

Allergens↗
PubMed1989

Distribution of cells bearing "rheumatic" antigens in peripheral blood of patients with rheumatic fever/rheumatic heart disease.

Cell surfaces of some peripheral blood cells from individuals with a history of rheumatic fever/rheumatic heart disease (RHD) have been demonstrated by the use of monoclonal antibodies to be antigenically distinct from the majority of the population. Our study examines the distribution of cells bearing these "rheumatic" antigens in 23 subjects with rheumatic fever/RHD of Maori, Polynesian and Caucasian ancestry and 182 members of their families (rheumatic fever/RHD families) as well as in 46 members of families in which no member had been demonstrated to have had rheumatic fever/RHD (control families). Mononuclear cells from the blood of all cooperating family members were prepared and non-T cells isolated by sheep red blood cell rosette depletion. The binding of monoclonal antibodies 83S19.23 and D8103 to non-T cells was measured using an immunoperoxidase technique. Subjects with rheumatic fever/RHD had a significantly higher proportion of cells binding the antibodies than the unaffected members of all families. Unaffected members of rheumatic fever/RHD families had significantly higher levels of such rheumatic cells than control families. An increase in the proportion of rheumatic cells with age was noted in unaffected members of rheumatic fever/RHD families but not in rheumatic fever/RHD subjects of control families. A level of 13% 83S19.23 positive non-T cells optimally discriminated between rheumatic and nonrheumatic individuals. The relative risk for rheumatic fever/RHD with 13% or greater positive cells was 9.48. The negative predictive value of having less than 13% positive cells was 98.3%. In the population studied, 83S19.23 seems especially capable of identifying those with low risk for rheumatic fever/RHD.

Aging↗
PubMed1988

Cell surface markers and cellular immune response associated with rheumatic heart disease: complex segregation analysis.

A series of functional and cell surface markers associated with a significantly increased risk of rheumatic heart disease were analyzed for the contribution of genetic factors in their presence. Peripheral blood lymphocytes from nine large kindreds from the New Zealand Maori, Polynesian, and Caucasian populations were isolated, purified, and evaluated with lymphocyte surface markers (monoclonals 83S.19.23 and D8103), as well as studied for blastogenic response to a purified group A streptococcal extracellular product, blastogen A. Segregation analysis of blastogenic response and percent of cells positive for these cell surface markers was consistent with genetic control by single major genes; however, the contribution by polygenes varied by marker, indicating heterogeneity of genetic control of identification of cell surface glycoproteins and blastogenic response to streptococcal products.

Antibodies, Monoclonal↗
PubMed1986

Mice naturally tolerant to C5 have T cells that suppress the response to this antigen.

We examined whether C5-sufficient mice which are naturally tolerant to this antigen have suppressor T cells to C5 humoral immune response. Two congenic strains of mice B10.D2 (NSN) and B10.D2 (OSN) differing only in the presence or absence of C5 were used. Irradiated (760 rds) sufficient hosts were reconstituted with a nonadherent spleen cell suspension from either sufficient or deficient mice or a mixture of both. Hemolytic C5 levels were assayed. Sufficient spleen cells appeared to prevent the drop of C5 level caused by anti-C5 antibody made by deficient spleen cells. Spleen cell suspensions from sufficient mice primed with deficient spleen cells exhibited better anti-C5 activity than normal sufficient spleen cell suspensions. This anti-C5 activity is abrogated by treatment of the NSN spleen cell suspensions obtained from NSN primed with OSN spleen cells with anti-Thy-1.2 antiserum and complement. Suppression of the humoral response to C5 failed to affect the anti-sheep red blood cell immune response. Suppressor T cells are resistant to low-dose irradiation, cortisone treatment and adult thymectomy. In contrast, they are sensitive to high doses of irradiation and both high and low doses of cyclophosphamide treatment. Thus, C5-sufficient mice, in contrast to C5-deficient mice, appear to have antigen-specific suppressor T cells which downregulate the humoral immune response to C5. In addition, we examined the relationship of these suppressor T cells to the state of tolerance in helper T cells of C5-sufficient mice. This was done in irradiated deficient mice which were repopulated with spleen cell suspensions selectively depleted of either Lyt-1+ or Lyt-2+ T cell subsets. These chimeras were challenged with murine C5 and both the primary and secondary immune response was measured by inhibition of the C5 hemolytic activity. It was found that only spleen cell suspensions of the deficient mice selectively depleted from the Lyt-2+ subset of T cells responded to the antigen both in the primary and secondary response. In contrast, either subset of T cells from the sufficient mice failed to respond. Thus, it appears that in sufficient mice helper T cells to C5 are intrinsically tolerant or physically and/or functionally deleted. In conclusion, the data suggest that both T cell compartments are unresponsive and play a role in the mechanism of tolerance to a physiologic antigen.

Animals↗
PubMed1986

Monocyte bone degradation: in vitro analysis of monocyte activity in patients with juvenile rheumatoid arthritis.

We examined the ability of the mononuclear phagocyte in vitro to degrade 45Ca-labeled bone particles to determine whether this assay allowed us to monitor disease activity in patients with juvenile rheumatoid arthritis. The monocytes from patients with juvenile rheumatoid arthritis receiving no anti-erosive therapy (n = 10) degraded significantly more bone than did cells obtained from normal controls (n = 10, P less than 0.001) or patients with juvenile rheumatoid arthritis receiving either gold thioglucose (n = 4, P less than 0.001) or D-penicillamine (n = 6, P less than 0.005). In two patients monitored for either 8 or 11 months, results of monocyte assays were found to parallel the clinical course. We conclude that in vitro monocyte bone degradation assays may provide a means of assessing joint activity in patients with juvenile rheumatoid arthritis. Further, this study and others indicate that mononuclear phagocytes are capable of causing erosive changes.

Adolescent↗
PubMed1986

Morphological abnormalities in the lymphocytes of patients with the Wiskott-Aldrich syndrome.

Lymphocytes from 18 patients with the Wiskott-Aldrich Syndrome (WAS) were examined by scanning electron microscopy (SEM). Most peripheral blood lymphocytes from normal individuals are covered with slender microvillus projections, but a large proportion of lymphocytes from WAS patients were found to be relatively devoid of microvilli. A lymphocyte morphology scoring system was developed to quantify the density of microvilli: Grade 4 classified those lymphocytes with greater than 75% of the surface covered with microvilli with progressive decrements to grade 1, which were those without microvilli. The mean lymphocyte morphology score of eight normal individuals was 3.62 +/- .22. The mean lymphocyte score of WAS patients was substantially lower (2.89 +/- .27, P less than .001). In addition, WAS lymphocytes often were qualitatively abnormal, with short, blunted microvilli. These morphological criteria were used to diagnose WAS from the cord blood lymphocytes of one "at-risk" patient. Thus, WAS is the first primary immunodeficiency in which morphological abnormalities have been identified that can aid in diagnosis.

Cell Membrane↗
PubMed1985

HLA gene frequencies in children and adults with systemic onset juvenile rheumatoid arthritis.

The HLA genetic region was studied in 51 patients with systemic onset juvenile rheumatoid arthritis: 35 with childhood onset and 16 with adult onset (adult Still's disease). HLA genotypes were established by including family members, 261 of whom were also typed in the study. The most marked difference between patients and controls involved the HLA-DR4 gene, which occurred with a frequency of 0.348 in the childhood onset patients and 0.170 in the controls (chi 2 = 8.97, P = 0.0028, adjusted P = 0.017). In contrast, the adult onset patients showed a marginal increase in HLA-DR7, but were similar to controls with respect to HLA-DR4. HLA-Bw35 was increased in children with systemic onset disease, in accordance with earlier findings. The results suggest that patients with systemic onset juvenile rheumatoid arthritis have complex HLA associations which are different in childhood onset and adult onset disease.

Adolescent↗
PubMed1984

Characterization of a human lymphocyte surface sialoglycoprotein that is defective in Wiskott-Aldrich syndrome.

gpL115 is a lymphocyte surface component that is deficient in patients with the X-chromosome-linked immune deficiency Wiskott-Aldrich syndrome (6). The glycoprotein nature of gpL115 is demonstrated through labeling in carbohydrate moieties by [3H]NaBH4 and its synthesis by lymphocytes through labeling with [35S]methionine. Native gpL115 adheres to wheat germ lectin-Sepharose and sialidase-treated gpL115 does not adhere, indicating that native gpL115 adheres via clusters of sialic acid residues. When tested on peanut lectin, which shows specificity for the disaccharide Gal beta 1-3GalNAc, gpL115 is nonadherent and sialidase-treated gpL115 is adherent, indicating the presence of the sequence sialic acid-Gal beta 1-3GalNAc, which is characteristic for O-linked (mucin-type, acidic-type) carbohydrates. A surface glycoprotein with all the above characteristics was found on the lymphoblastoid cell line CEM. CEM cells were used as immunogen to generate the monoclonal antibody L10, an IgG1, which binds native and sialidase-treated gpL115 . Sialidase-treatment of gpL115 significantly alters its physical properties, reducing its electrophoretic mobility and changing its behavior on isoelectrofocusing. Cumulatively, these findings indicate that gpL115 , like glycophorin of erythrocytes and GPIb of platelets, is a sialoglyco protein with significant quantities of O-linked carbohydrate. On treatment with limiting sialidase concentrations, gpL115 of normal lymphocytes is transformed into a series of partially desialylated species of decreasing electrophoretic mobility. This finding resembles the situation with lymphocytes of some Wiskott-Aldrich syndrome patients. Lymphocytes of eight Wiskott-Aldrich syndrome patients were found to be deficient in 125I-labeled gpL115 . Lymphocytes from three of these patients displayed an abnormal 125I-component of apparent mol wt 135,000.

Antibodies, Monoclonal↗
PubMed1984

Safety and efficacy of a monomeric, functionally intact intravenous IgG preparation in patients with primary immunodeficiency syndromes.

Results of an open, phase II clinical trial on therapy with an iv IgG preparation in patients with primary antibody-deficiency syndromes are reported. Three hundred infusions of the product, an intact monomeric IgG preparation, were given to 16 patients for an average of 14 (+/- 0.7) months, the dose being 220 (+/- 26.9) mg/kg/month. Only two minor adverse reactions occurred. This preparation did not produce transient leukopenia on infusion. Preinfusion serum IgG levels increased continuously in the course of treatment (average values: 325 +/- 51 at the beginning of therapy, 438 +/- 59 at 6 months, 568 +/- 75 at 12 months, 631 +/- 52 at the end of treatment). The infusions were well accepted and well tolerated by the patients, and the clinical efficacy was highly superior to intramuscular immunoglobulin.

Adolescent↗