Immunology. Sinking surveillance's flagship.
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Animals↗
Biomedical subjects
G Klein
Publications and source records attributed to G Klein.
Constitutive IL-10 production accounts for the high NK sensitivity, low MHC class I expression, and poor transporter associated with antigen processing (TAP)-1/2 function in the prototype NK target YAC-1.
Tumor cells that are treated with rIL-10 or transfected with the IL-10 gene show phenotypic changes. These include low but peptide-inducible expression of MHC class I, low sensitivity to specific CTL-mediated lysis, and increased NK sensitivity. In vitro-established mouse tumor lines were screened for IL-10 expression and production, and a large proportion of plasmocytomas or T cell lymphomas were found to produce IL-10. Since one of these lines was the prototype NK target cell YAC-1, we investigated whether the high IL-10 production of this cell line was related to its high NK sensitivity and its defects in MHC class I expression. The decrease in H-2 expression following the in vitro culture of in vivo-passaged YAC-1 cells was accompanied by a gradual increase in IL-10 production, whereas the reverse was found when passing in vitro-grown YAC-1 in vivo as an ascites tumor in syngenic mice. In addition, differences in YAC-1 MHC class I expression correlated with alterations in the functional activity of TAP-1/2 proteins. YAC-1 cells that were transduced with a retroviral IL-10 antisense construct (Y-IL-10 AS) only produced about half of the IL-10 that was produced by YAC-1 transduced with the control construct (Y-IL-10 Mock). Relative to Y-IL-10 Mock cells, the expression of H-2 on Y-IL-10 AS cells was markedly increased, and NK sensitivity was decreased. These data argue for a mechanism wherein IL-10 production is causally related to the low H-2 expression, decreased TAP function, and high NK sensitivity of YAC-1 cells.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
bcl-2 rearrangement detected by pulsed-field gel electrophoresis (PFGF) in B-chronic lymphocytic leukemia (CLL) cells.
B-chronic lymphocytic leukemia (CLL) is characterized by an accumulation of long-lived, resting B cells expressing the Bcl-2 protein. However, less than 10% of the CLL patients shows bcl-2 gene rearrangement in blood cells, using traditional Southern blotting analysis. In the present study, rearrangement of the bcl-2 gene in CLL cells was studied by pulsed-field gel electrophoresis (PFGE). With this method, large DNA fragments (> 50-10,000 kb) could be analyzed. Blood CLL cells from 9 of 9 patients and 2 of 2 CLL cell lines showed rearranged bcl-2 gene. In comparison, healthy blood B cells and lymphoblastoid cell lines (LCLs) established from normal peripheral blood lymphocytes of the patients showed only germ line configuration. Thus, the possibility of restriction fragment length polymorphisms (RFLPs) in this gene could be excluded. The primary cell involved in CLL might be a progenitor B cell that has accidentally rearranged the bcl-2 gene. As a consequence, such cells express stable amount of Bcl-2 protein and do not enter apoptosis. During prolonged survival, such cells may acquire secondary changes including chromosomal translocations and mutations.
B-Lymphocytes↗
Taxonomy and physiology of probiotic lactic acid bacteria.
The current taxonomy of probiotic lactic acid bacteria is reviewed with special focus on the genera Lactobacillus, Bifidobacterium and Enterococcus. The physiology and taxonomic position of species and strains of these genera were investigated by phenotypic and genomic methods. In total, 176 strains, including the type strains, have been included. Phenotypic methods applied were based on biochemical, enzymatical and physiological characteristics, including growth temperatures, cell wall analysis and analysis of the total soluble cytoplasmatic proteins. Genomic methods used were pulsed field gel electrophoresis (PFGE), randomly amplified polymorphic DNA-PCR (RAPD-PCR) and DNA-DNA hybridization for bifidobacteria. In the genus Lactobacillus the following species of importance as probiotics were investigated: L. acidophilus group, L. casei group and L. reuteri/L. fermentum group. Most strains referred to as L. acidophilus in probiotic products could be identified either as L. gasseri or as L. johnsonii, both members of the L. acidophilus group. A similar situation could be shown in the L. casei group, where most of the strains named L. casei belonged to L. paracasei subspp. A recent proposal to reject the species L. paracasei and to include this species in the restored species L. casei with a neotype strain was supported by protein analysis. Bifidobacterium spp. strains have been reported to be used for production of fermented dairy and recently of probiotic products. According to phenotypic features and confirmed by DNA-DNA hybridization most of the bifidobacteria strains from dairy origin belonged to B. animalis, although they were often declared as B. longum by the manufacturer. From the genus Enterococcus, probiotic Ec. faecium strains were investigated with regard to the vanA-mediated resistance against glycopeptides. These unwanted resistances could be ruled out by analysis of the 39 kDa resistance protein. In conclusion, the taxonomy and physiology of probiotic lactic acid bacteria can only be understood by using polyphasic taxonomy combining morphological, biochemical and physiological characteristics with molecular-based phenotypic and genomic techniques.
Bifidobacterium↗
An enantioselective fluorimetric assay for alcohol dehydrogenases using albumin-catalyzed beta-elimination of umbelliferone.
3-hydroxybutyl umbelliferyl ethers (R)-1 and (S)-1 are fluorogenic substrates for alcohol dehydrogenases. Their oxidation forms ketone 2, which undergoes beta-elimination of umbelliferone under catalysis by bovine serum albumin, leading to a > 20-fold fluorescence increase at lambda em = 460 +/- 20 nm (lambda ex = 360 +/- 20 nm). Enantioselectivity is determined in two separate tests with each enantiomeric substrate.
Alcohol Dehydrogenase↗
Murine cytotoxic T lymphocytes recognize an epitope in an EBNA-1 fragment, but fail to lyse EBNA-1-expressing mouse cells.
Major histocompatibility complex class I-restricted cytotoxic T lymphocytes (CTLs) specific for epitopes within eight of the nine Epstein Barr Virus (EBV)-encoded latency-associated proteins have been recovered from EBV-infected human subjects by restimulation of lymphocytes in vitro. However, human class I-restricted CTL responses capable of recognizing EBNA-1 expressing cells were not detected in these studies. We have raised a murine CTL line that recognizes an epitope within EBNA-1 by immunizing mice with a vaccinia virus encoding a COOH-terminal EBNA-1 fragment. This novel CTL line was used to investigate whether the epitope (positions 509-517 in EBNA-1, presented through Kd) was presented to CTL by mouse cells expressing full-length EBNA-1 or a deletion mutant of EBNA-1, lacking the Glycine-Alanine (Gly-Ala)-rich region. Cells expressing full-length EBNA-1 are not lysed by the CTL line, whereas cells expressing the Gly-Ala deletion mutant are recognized. These results suggest that epitopes from full-length EBNA-1 are poorly presented, and that the Gly-Ala-rich region is responsible for this phenomenon. The inefficient presentation of EBNA-1-derived epitopes may explain the absence or rarity of EBNA-1-specific CTLs in vivo, a strategy that may allow EBV to maintain persistence within the immunocompetent host without being eliminated by CTLs.
Animals↗
High levels of macrophage inflammatory protein-1alpha correlate with prolactin in female patients with active rheumatoid arthritis.
The relationship between the endocrine immune modulator prolactin and the macrophage activation parameter MIP-1alpha (macrophage inflammatory protein-1alpha) was investigated in 61 females with rheumatoid arthritis (RA). The chemokine MIP-1alpha was found to be twice as high in active than in inactive RA. Parallel to the inflammatory activity (acute phase response and joint count) and high levels of MIP-1alpha there were markable changes of serum prolactin. MIP-1alpha seems to have an influence on the pituitary hormone secretion. A significant correlation between prolactin and MIP-1alpha (r = 0.67; p < or = 0.00001) point out the bidirectional influence of the immune and endocrine system in RA.
Adult↗
Post-transplantation lymphoproliferative disease. Introduction.
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Bone Marrow Transplantation↗
Cloning, sequencing and developmental expression of the genes encoding S4 and S10 ribosomal proteins in the cellular slime mould Dictyostelium discoideum.
The sequences of the rps4 and rps10 genes encoding the Dictyostelium discoideum homologues of the basic ribosomal proteins S4 and S10 were determined from cDNA and genomic DNA clones. They are expressed respectively as 266 and 153 amino-acid-long proteins. In both cases, the N-terminal methionine is cleaved in the mature proteins. S4 contains two putative nuclear targeting signals and displays a strong overall identity (around 60%) to eukaryotic S4 homologues. The rps10 gene harbours a 314-bp intron located close to its 5'-coding end. The overall identity between D. discoideum S10 and eukaryotic homologues is around 38% and rises to 53% in the N-terminal domain. Southern blots suggest that both S4 and S10 are encoded by single genes that are regulated during development. The corresponding mRNAs decrease sharply after 8 h of differentiation.
Amino Acid Sequence↗
Cloning and characterization of the dnaK heat shock operon of the marine bacterium Vibrio harveyi.
We cloned the DNA region of the Vibrio harveyi chromosome containing the heat shock genes dnaK and dnaJ and sequenced them. These genes are arranged in the chromosome in the order dnaK-dnaJ, as in other proteobacteria of the alpha and gamma subdivisions. The dnaK gene is 1923 nucleotides in length and codes for a protein of 640 amino acid residues, with a predicted molecular mass of 69,076 Da and 81.2% similarity to the DnaK protein of Escherichia coli. The V. harveyi dnaJ gene has a coding sequence of 1158 nucleotides. The predicted DnaJ protein contains 385 amino acids, its calculated molecular mass is 41,619 Da and it has 74.7% similarity to the DnaJ protein of E. coli. Northern hybridization experiments with RNA from V. harveyi cells and a DNA probe carrying both the dnaK and dnaJ genes showed a single, heat-inducible transcript, indicating that these genes form an operon. Primer extension analysis revealed five heat-inducible transcriptional start sites upstream of the dnaK gene, two of which (T1 and T4) are preceded by sequences typical of the E. coli heat shock promoters recognized by the sigma 32 (sigma32) factor. Location of these promoters is highly similar to that of the E. coli dnaK promoters. No transcriptional start sites were detected upstream of the dnaJ gene. The V. harveyi dnaKJ operon cloned in a plasmid in E. coli cells was transcribed in a sigma32 dependent manner and the size of the transcript, the kinetics of transcription, and the transcriptional start sites were as in V. harveyi cells. This indicates a high conservation of the transcriptional heat shock regulatory elements between E. coli and V. harveyi, both belonging to the gamma subdivision of proteobacteria. We tested the ability of the cloned dnaKJ genes to complement E. coli dnaK and dnaJ mutants and found that V. harveyi DnaJ restored a thermoresistant phenotype to dnaJ mutants and enabled lambda phage to grow in the mutant cells. V. harveyi DnaK did not suppress the thermosensitivity of dnaK mutants but complemented the dnaK deletion mutant with respect to growth of lambda phage. V. harveyi DnaK, in contrast to DnaJ, failed to modulate the heat shock response in E. coli. Our results suggest that the DnaK chaperone may be more species specific than the DnaJ chaperone.
Amino Acid Sequence↗
Comparative sensitivity of 20 bioassays for soil quality.
Increasing evidence suggests that the use of a single bioassay will never provide a full picture of the quality of the environment. Only a test battery, composed of bioassays of different animal and plant species from different trophic levels will reduce uncertainty, allowing an accurate assessment of the quality of the environment. In the present study, a test battery composed of 20 bioassays of varying biological endpoints has been compared. Apart from lethality and reproductive failure in earthworms, springtails, nematoda, algae and vascular plants, these endpoints also included bioavailibility of metals (bacteria), heat-shock induction (nematodes, algae), DNA damage (bacteria, earthworm, vascular plants), beta-galactosidase (Daphnia) and esterase activity (algae) and a range of immunological parameters (earthworm). Four chemicals (cadmium, phenol, pentachlorophenol and trifluralin)--each representing a different toxic mode of action--were applied in a dilution series (from 1 mg/kg up to 1000 mg/kg) onto OECD standard soil. The tests have been performed both on these artificially contaminated soil samples and on aqueous extracts subsequently obtained from these soils. The results show that the immunological parameters and the loss of weight in the earthworms were among the most sensitive solid-phase assays. Esterase inhibition and heat-shock induction in algae were shown to be extremely sensitive when applied to soil extracts. As previously shown at the species level, no single biological endpoint was shown to be the most sensitive for all four modes of toxic action.
Animals↗
Foulds' dangerous idea revisited: the multistep development of tumors 40 years later.
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Animals↗
Requirement of the CD8+ or CD4+ T lymphocyte subsets for the rejection of lymphoma and fibrosarcoma grafts studied in gene knockout hosts.
Rejections of the retrovirus induced lymphomas (ALC and RBL-5) and the methylcholanthrene (MCA) induced fibrosarcoma (MC57X) grafts were tested in syngeneic CD8 and CD4 single and double knockout C57BL/6 mice. The results with the lymphomas showed that the CD8+ T cell deficiency prevented the development of rejection response induced by immunization. Deficiency of the CD4+ T subset abrogated also the rejection of ALC. Immunity against the fibrosarcoma cells developed in both type of single knockout mice, but not in the ones which lacked both CD4+ and CD8+ T cells. Thus CD8+ T cells were required for rejection of the lymphoma cells, while the CD4+ T cells only mediated a weak response. In absence of CD8+ T cells, CD4+ T cells were sufficient to reject the fibrosarcoma cells.
Animals↗
Simultaneous detection of two independent antigens by double staining with two mouse monoclonal antibodies.
Simultaneous detection of two antigens by immunostaining usually requires primary antibodies from two different species or a hapten modification of one of the antibodies if they are from the same species. A novel double staining method is described for immunodetection of two independent antigens using two mouse monoclonal antibodies. The principle of the method is the following: The first antigen is detected by a monoclonal antibody that is diluted so extensively that it cannot be recognized with conventional detection systems. A highly sensitive biotin-tyramide amplification system is used to identify this antibody. The second antigen is stained with a monoclonal antibody by dilution and detected by conventional immunostaining. The method was tested for both alkaline-phosphatase staining on paraffin sections and immunofluorescence staining on cultured cells in cytospin preparation. The absence of cross-reaction in the former system was demonstrated by the mutually exclusive detection of T- and B-cells in human lymph nodes or T-cells and carcinoma cells in nasopharyngeal carcinoma biopsies. Similarly, the EBV encoded EBNA2 and ZEBRA proteins showed a mutually exclusive staining by immunofluorescence on B95-8 cells. The method could be used to demonstrate co-expression of two independent antigens in the same cells, such as PCNA and keratin in carcinoma cells in paraffin sections and for EBNA2 and LMP1 EBV proteins in immunofluorescence preparations of B95-8 cells.
Alkaline Phosphatase↗
Cell binding properties of collagen type XIV for human hematopoietic cells.
Collagen XIV, which belongs to the subclass of fibril-associated collagens with interrupted triple helices (FACITs), is a homotrimeric molecule consisting of three alpha 1 (XIV) chains. Collagen type XIV is strongly expressed in the native human bone marrow, as shown by immunofluorescence staining and immunoblotting with an affinity-purified antibody. Hematopoietic cell lines of myeloid (KG1a, U937, K562) and lymphoid (U266, IM-9) origin were able to attach firmly to purified human collagen XIV preparations. Attachment of these cells was shown to be concentration-dependent. However, other hematopoietic cell lines tested were unable to adhere to collagen XIV, indicating restriction of this cellular interaction. The cellular receptors involved in cell binding to collagen type XIV are probably membrane-bound heparansulfate proteoglycans, since only the the addition of heparin inhibited attachment of the hematopoietic cells to collagen XIV in a concentration-dependent manner. Antibodies against the beta 1-integrin subunit could not interfere with binding to collagen type XIV. Using purified fragments of collagen XIV, it could be demonstrated that at least two different heparin-sensitive adhesion sites are present in the N-terminal globular domain and in the triple-helical domain. These data indicate that collagen XIV represents another collagen type expressed in human bone marrow with strong cell binding properties for defined populations of hematopoietic cells.
Bone Marrow Cells↗
Mitogenic and adhesive effects of tenascin-C on human hematopoietic cells are mediated by various functional domains.
In the adult organism, the extracellular matrix molecule tenascin-C is prominently expressed in the bone marrow. Bone marrow mononuclear cells can adhere to plastic-immobilized tenascin-C, and in the present study we have used bacterial expression proteins to map the domains of tenascin-C responsible for binding of hematopoietic cells. A strong binding site was found to be located within the fibrinogen-like domain, and this binding could be inhibited by heparin, suggesting interactions with membrane-bound heparan sulfate proteoglycans. A second strong binding site was identified within the fibronectin type III-like repeats 6-8, and was also inhibitable by heparin. Adhesion to both attachment sites could not be blocked by various anti-integrin antibodies. A third hematopoietic cell binding site is located in the fibronectin type III-like repeats 1-5, which harbor an RGD sequence in the third fibronectin type III-like repeat. Binding to this domain, however, seems to be RGD-independent, since RGD-containing peptides could not inhibit cell binding; the addition of heparin also did not block adhesion to this domain. Since contradictory results had been reported on a proliferative effect of soluble tenascin-C, we also analyzed its activity on hematopoietic cells. The heterogeneous bone marrow mononuclear cells show a striking proliferative response in the presence of tenascin-C which is concentration-dependent. This result indicates a strong mitogenic activity of tenascin-C on primary hematopoietic cells. Using recombinant fragments of human tenascin-C, we identified several mitogenic domains within the tenascin-C molecule. These adhesive and mitogenic effects of tenascin-C suggest a direct functional association with proliferation and differentiation of hematopoietic cells within the bone marrow microenvironment.
Binding Sites↗
Interferon-gamma in the treatment of systemic sclerosis: a randomized controlled multicentre trial.
We report the results of a randomized controlled multicentre study on interferon-gamma (IFN-gamma) treatment of systemic sclerosis as determined by skin sclerosis, renal and other organ involvement, global assessment, subjective symptoms and quality of life. Forty-four patients were enrolled into the trial, 27 in the treatment group and 17 in the control group. All patients presented with type I or type II scleroderma. Twenty-nine patients (64%) finished the study. The mean duration of Raynaud's phenomenon and skin sclerosis was 15.3 and 10.8 years, respectively. The skin scores tended to improve in the treatment group (P > 0.05). Mouth aperture increased significantly from 38.5 to 47.7 mm in the treatment group (P < 0.001). Subanalysis of IFN-gamma treated patients with normalized skin sclerosis scores >/=1 showed significant improvement in both skin involvement and subjective symptoms (P < 0.05). Organ involvement improved in eight of 18 treatment patients and in three of 11 control patients. It worsened in three of 18 treatment patients and in four of 11 control patients. One control patient died due to cardiorespiratory failure during the study. No deterioration of renal function occurred during IFN-gamma treatment. There was a significant improvement in quality of life parameters in the control group but not in the treatment group. Plasma levels of neopterin increased significantly during IFN-gamma treatment but not in the control group, whereas N-terminal procollagen III peptide levels did not change in either group. There was a high frequency of mild to moderate influenza-like adverse events during IFN-gamma treatment. Only four of nine drop-out patients, however, experienced symptoms most probably associated with IFN-gamma treatment. We conclude that IFN-gamma therapy has mild beneficial effects on skin sclerosis and disease-associated symptoms in type I and II scleroderma. IFN-gamma treatment was associated with acceptable tolerability and did not induce major renal dysfunction in our patients.
Adolescent↗
The supply of and demand for informal and professional care for patients with rheumatoid arthritis.
The objective of this study is to determine supply of, and demand for, informal care for rheumatoid arthritis (RA) patients and to evaluate the factors that contribute to the amounts of help needed and received from professional and informal care providers at home. Data were collected by questionnaire from 229 RA patients and 174 informal caregivers. Most of the help required is also received, though 24% of the patients did not receive help for one or more tasks. Most help given at home is by informal caregivers. The amount of help needed is related primarily to the patient's physical condition, sex, and self-efficacy expectations towards coping with RA. The amount of help received from informal caregivers is largely explained by the physical condition and the marital status of the patient, the sex of the caregiver, the patient's self-efficacy expectations towards coping with RA, and the age of the patient. The amount of help received from health professionals is related primarily to the marital status and the physical condition of the patient.
Activities of Daily Living↗