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M Kress

Publications and source records attributed to M Kress.

At least 73 records · Page 4Linked to original sources
PubMed1990

Graft-versus-host mortality induced by noncytolytic CD4+ T cell clones specific for non-H-2 antigens.

UNLABELLED: The relative contribution of individual non-H-2 Ag and of T cell subsets that initiate graft-vs-host reaction (GVHR) as well as the mechanism responsible for histopathologic lesions are still a matter of debate. To address these questions and to favor the selection of T cells primed in vivo against non-H-2 Ag important in GVHR we derived T cell clones from spleens of (DBA/2 x B10.D2)F1 (H-2d) mice developing this reaction after the graft of B10.D2 (H-2d) cells incompatible for numerous non-H-2 Ag plus Mlsa. The pattern of reactivity of eight selected clones against cells from different strains of mice including (BXD)RI strains indicated that one CD4+ clone is specific for Mlsa and seven additional clones (six CD4+ and one CD8+) are specific for four different non-H-2 Ag (Ag.I-IV) and proliferate in an H-2-restricted manner. The same series of experiments suggested that Ag.I and II are poorly polymorphic and allowed to propose the localisation of the genes controlling Ag.I (chromosome 1) and Ag.III (chromosome 4). All the clones show a triple (alpha, beta, gamma) mRNA transcript for TCR but at their surface they express the alpha/beta-heterodimer. The clone specific for Mlsa expresses V beta 6 and that specific for Ag.IV expresses V beta 8.1. Rapid mortality accompanied by clinical and histologic signs of severe GVHR was observed after administration of CD4+ clones (together with host-syngeneic bone marrow) derived early after grafting and specific for Ag.I and II but not after administration of: 1) CD8+ cytolytic clone derived early after grafting and specific for Ag.IV; 2) CD4+ clones derived late after grafting and specific for Ag.III; and 3) CD4+ clone specific for Mlsa. A clear correlation was established between the capacity of CD4+ clones to induce GVHR mortality, to mediate host-specific DTH and to release a high level of TNF. IN CONCLUSION: 1) the reaction against a single non-H-2 Ag is sufficient to provoke lethal GVHR; 2) the capacity to provoke GVHR mortality depends on antigenic specificity and functional properties of the responding clones; 3) the inflammatory process mediated by CD4+ clones may play a major role whereas the specific CD8+ T cell-mediated cytolytic activity is not necessarily lethal.

Animals↗
PubMed1990

A gene that encodes a protein consisting solely of zinc finger domains is preferentially expressed in transformed mouse cells.

We describe the cloning and characterization of the mouse MOK-2 gene, a new member of the Krüppel family of zinc finger proteins. Sequencing of both cDNA and genomic clones showed that the predicted MOK-2 protein consists of seven zinc finger domains with only five additional amino acids. The finger domains of MOK-2 are highly homologous to one another but not to those of other zinc finger proteins. MOK-2 is preferentially expressed in transformed cell lines, brain tissue, and testis tissue. Its possible role in cellular transformation is discussed.

Amino Acid Sequence↗
PubMed1989

Expression of a mouse replacement histone H3.3 gene with a highly conserved 3' noncoding region during SV40- and polyoma-induced Go to S-phase transition.

We have isolated and sequenced a mouse replacement variant histone H3.3 cDNA. It corresponds to the most abundant mRNA expressed from a unique gene by the use of one out of three polyadenylation sites. The 3' non coding region of H3.3 is very long (approximately 1100 nt) and highly conserved throughout evolution since it is about 95% homologous to the 3' non coding region of the chicken H3.3B gene. We studied the expression of the H3.3 gene during SV40- and polyoma-induced mitotic host reaction in confluent, Go-arrested primary mouse kidney cell cultures. H3.3 replacement variant mRNA steady state levels increased during the Go to S-phase transition, apparently as the result of two mechanisms: one related to cell growth, whereas the other was linked to cellular DNA synthesis. The latter mechanism was however far less pronounced than with replication histone variant mRNAs. The biological implications of these results are discussed.

Amino Acid Sequence↗
PubMed1989

SV40-induced expression of mouse gene 24p3 involves a post-transcriptional mechanism.

SV40 and polyoma virus induce a mitotic host reaction in confluent, Go-arrested primary mouse kidney cell cultures. To define the primary effects of infection we constructed a cDNA library corresponding to polyA+ mRNA isolated shortly after onset of polyoma T-antigen synthesis. By differential screening of the library we have isolated and then sequenced cDNA recombinant 24p3; determined by Northern blotting, 24p3 mRNA steady state levels increased in parallel with polyoma and SV40 T-antigen synthesis. Since this rapid and early increase was particularly striking (14-20 fold) in SV40-infected cells, we studied the molecular mechanism of induction in this virus-cell system. We show that wt SV40 large T-antigen is required for the increase in 24p3 mRNA levels. The results tend to exclude that this increase is due to an SV40-induced stabilization of the 24p3 mRNA, or to an SV40-induced stimulation of transcription of the 24p3 gene; they are compatible with the working hypothesis that SV40 large T-antigen increases the efficiency of processing, possibly splicing, of the 24p3 pre-mRNA. The biological implications of these results are discussed.

Amino Acid Sequence↗
PubMed1988

Vitellogenin gene expression in male rainbow trout (Salmo gairdneri).

Estrogen has a marked effect on the expression of vitellogenin, the egg yolk precursor protein in the liver of egg-laying vertebrates. cDNA clones specific for trout vitellogenin mRNA have been used to study the expression of the vitellogenin genes in rainbow trout (Salmo gairdneri). The steady-state levels of vitellogenin mRNA in the liver of male rainbow trout were measured during primary and secondary stimulation with estradiol. The kinetics of induction in trout appear to be very similar to those seen in Xenopus and chicken in that a lag of approximately 2 days is observed in the accumulation of serum vitellogenin during primary induction. This lag is not observed during the secondary stimulation. The primary induction of vitellogenin mRNA in trout liver, using a single injection of estradiol (3 mg/kg body wt) results in a short-lived rise, reaching a maximum level of 260 ppm total RNA on Day 2. Using silastic implants of estradiol to induce a primary response produces a large increase in the steady-state level of vitellogenin mRNA which reaches a maximum of 2750 ppm total RNA on Day 10. During secondary stimulation, using silastic tubing the maximum level reached was 1200 ppm of the total RNA on Day 7, approximately half the level seen in the primary induction using the silastic implants. The difference in these two levels is due to an increase in the steady-state levels of rRNA, which appear to increase between Days 10 and 21 after the primary stimulation. These results demonstrate that the induction of vitellogenesis in the trout by estradiol involves changes in the steady-state levels of a number of different mRNA and rRNA sequences and resembles that seen in Xenopus and chicken.

Amino Acid Sequence↗
PubMed1988

[Sequential treatment of progressive metastatic colorectal cancer with 5-fluorouracil/folinic acid, dipyramidole and mitomycin C].

A number of reports have described enhanced therapeutic activity of 5-fluorouracil (5-FU) when combined with high-dose folinic acid (dl-CF). In the present phase-II study 35 patients with colorectal cancer were entered into a first-line chemotherapeutic protocol consisting of dl-CF 200 mg/m2 i.v. push directly followed by 340 mg/m2 5-FU i.v. pushon - days 1-5. Thus far a response rate of 37.5% (12 PR) has been achieved, and minor responses or no change were registered in 43.7% (14 MR or NC), lowering the rate of primary therapeutic failures to 18.8%. Median time to progression was 6.2 months. Toxic side effects consisted mainly of diarrhea, nausea and mucositis. As second-line therapy 5-FU/dl-CF and dipyramidole p.o. were administered to 10 patients with resulting 4 NC. Mitomycin C was given to 9 patients as a third-line regimen with resulting 5 NC for 2-4 months.

Adult↗
PubMed1988

X-ray diffraction studies on muscle during rapid shortening and their implications concerning crossbridge behaviour.

In isometric contraction, a high proportion of crossbridges are always in the attached state and crossbridge cycling is slow. During shortening, crossbridges must be entering the detached state at a higher rate, as they come to the end of their working strokes. The size of the population of detached crossbridges will then depend on the re-attachment rate and it is therefore of some interest to find out whether a significant detached population can be detected. Observations on the equatorial X-ray diffraction pattern indicate that this is the case at higher speeds of shortening, for example at a speed where the detachment rate must be of the order of 200 per second. In a muscle under these conditions, the 59 A and 51 A actin layer line reflections decrease in intensity compared to their values during isometric contraction. This decrease does not appear to be associated with a change in structure of the actin-troponin-tropomyosin complex, since the second actin layer-line reflection remains virtually unchanged in intensity. Thus the change is likely to arise from either a different total number of attached crossbridges, or a different number of attached crossbridges in the tension generating state. The result provides some further evidence for specific helical labelling of the actin structure by crossbridges during contraction, as do some recent electronmicroscope studies of rapidly frozen contracting muscle.

Actins↗
PubMed1987

X-ray diffraction studies of the structural state of crossbridges in skinned frog sartorius muscle at low ionic strength.

Low-angle X-ray diffraction diagrams were obtained from chemically skinned frog sartorius muscles under low ionic strength relaxing conditions. Experiments on single muscle fibres from rabbit muscle and on muscle proteins in solution have suggested the presence of a 'low ionic strength attached state' of the myosin crossbridges to actin, in which the overall ATP splitting and force-generating cycle is still blocked. This opened up the possibility that structural information about one of the intermediate states in the crossbridge cycle might be obtained under these conditions. Using synchrotron radiation as a high intensity X-ray source we were able to record the appropriate diffraction diagrams with short exposure times and were able to compare the same muscles at normal and at low ionic strength. Changes in the intensities of the equatorial reflections an increase in the 143 A meridional intensity can be interpreted in a similar way. However, these attached bridges do not give rise to changes in the actin-based layer line reflections, nor is their presence associated with a weakening of the myosin layer line pattern. These results provide further evidence for the existence of bound states of crossbridges, in which their orientation relative to actin is not sharply defined.

Actins↗
PubMed1987

Cloning and characterization of a cDNA from Xenopus laevis coding for a protein homologous to human and murine p53.

A Xenopus laevis oocyte cDNA library was screened with a murine p53 cDNA probe for the presence of p53-related clones. Several such clones were isolated and analysed. The nucleotide sequence of the largest cDNA clone (2.2 kb) showed a high degree of homology with the human (68%) and murine (70%) p53 coding sequences. This clone contains a single large open-reading frame, coding for a protein of 363 amino acids, which is 51% homologous to human p53 and 57% homologous to murine p53. Furthermore, five highly conserved internal regions were found in all three proteins. The three proteins have a highly similar amino acid composition (including, notably, the presence of a high proportion of proline residues), and they display a comparable distribution of charged amino acids and hydropathic index profile. The in vitro transcription-translation products of the X. laevis clone were successfully immunoprecipitated by human anti-p53 sera, demonstrating that there is at least one epitope in common between the X. laevis protein and human, and possibly murine, p53.

Amino Acid Sequence↗
PubMed1986

Structural changes during activation of frog muscle studied by time-resolved X-ray diffraction.

The pattern given by contracting frog muscle can be followed with high time resolution using synchrotron radiation as a high-intensity X-ray source. We have studied the behaviour of the second actin layer-line (axial spacing of approximately 179 A) at an off-meridional spacing of approximately 0.023 A-1, a region of the diagram that is sensitive to the position of tropomyosin in the thin filaments. In confirmation of earlier work, we find that there is a substantial increase in the intensity of this part of the pattern during contraction. We find that the reflection reaches half its final intensity about 17 milliseconds after the stimulus at 6 degrees C. The changes in the equatorial reflections, which arise from movement of crossbridges towards the thin filaments, occur with a delay of about 12 to 17 milliseconds relative to this change in the actin pattern. In over-stretched muscle, where thick and thin filaments no longer overlap, the changes in the actin second layer-line still take place upon stimulation with a time course and intensity similar to that observed at full overlap. This indicates that tropomyosin movement, in response to calcium binding to troponin, is the first structural step in muscular contraction, and is the prerequisite for myosin binding. A change in intensity similar to that found in contracting muscle is seen in rigor, where tropomyosin is probably locked in the active position. During relaxation the earlier stages in the decrease in intensity of the second actin layer-line take place significantly sooner after the last stimulus than tension decay. In over-stretched muscles the intensity decay is appreciably faster than in the same muscles at rest length, where attached crossbridges may interfere with the return of tropomyosin to its resting position.

Actins↗
PubMed1986

A transcriptional enhancer and an interferon-responsive sequence in major histocompatibility complex class I genes.

The major histocompatibility complex class I antigens play an indispensable role in cell-cell interactions. Perturbation of their expression has been shown to have deleterious physiological consequences, including the escape of transformed cells from immune detection. In an attempt to understand how class I genes are regulated, we dissected the Ld gene to identify potential control regions. By using a test vector containing the simian virus 40 early promoter placed upstream of the bacterial chloramphenicol acetyltransferase (cat) gene, we demonstrated the presence of a transcriptional enhancer within the 5'-flanking region. The sequence is functional in both orientations and has been mapped within 350 base pairs upstream of the Ld transcriptional start site. Although human adenovirus 12 can suppress endogenous class I genes, it cannot down-regulate the activity of the transiently transfected cat gene which has been placed under the control of the Ld enhancer and promoter. Our results suggested that if the human adenovirus 12-induced function regulates the expression of class I genes by a trans mechanism, then its target site must not be within 1.9 kilobases of the 5'-flanking region. Treatment of cells with interferon increases the accumulation of class I transcripts. Expression of the cat gene under the control of the Ld enhancer and promoter also can be up-regulated by interferon. Our study shows that the target sequence required for this enhancement resides, at least in part, within the same 350-base pair segment which contains the transcriptional enhancer.

Adenoviruses, Human↗
PubMed1985

Comparison of HLA class I gene sequences. Derivation of locus-specific oligonucleotide probes specific for HLA-A, HLA-B, and HLA-C genes.

The major histocompatibility complex in man contains at least 20 class I genes. Included within this family are three closely linked loci with 11-47 codominant alleles that encode the classical transplantation antigens HLA-A, -B, and -C. The study of individual HLA-A, -B, and -C genes is complicated both by the high degree of sequence homology among all members of the class I gene family and by the high degree of polymorphism exhibited by HLA-A, -B, and -C genes. Identification of potential locus-specific regions suitable for use as unique probes has been limited by the small number of nucleotide sequences available for comparison. In the present study, the nucleotide sequences of two cDNA clones, designated HLA-4 and HLA-10, that encode previously unsequenced alleles of HLA-C and HLA-A genes, respectively, are compared with those of other class I genes. From these intergenic and interallelic comparisons, it was deduced that the nucleotide sequence encoding amino acids 291-299 of the transmembrane region showed sufficient divergence between loci and similarity between alleles, to be suitable for the generation of locus-specific probes. Synthetic oligonucleotides were generated and shown to be highly locus-specific in hybridization. These probes were used successfully for the quantitation of the relative amounts of mRNA transcribed in human liver from HLA-A, -B, and -C genes; they should greatly simplify future studies of restriction fragment length polymorphisms of HLA-A, -B, and -C alleles as genetic markers of disease susceptibility.

Alleles↗
PubMed1985

An H-2K gene of the tw32 mutant at the T/t complex is a close parent of an H-2Kq gene.

Two recombinant mice have been recovered from the progeny of Ttf/tw32 + animals. They have lost the tw32 lethality factor(s) and gained tufted, presumably from the T chromosome. Southern blot analysis of class I genes of these two new partial tPA027 and tPA286 haplotypes indicates that they have retained at least part of the major histocompatibility complex of the tw32 chromosome (H-2 haplotype H-2w28). We have prepared a phage library of Eco RI-digested DNA from homozygous tPA027 animals. Upon screening the library with a cDNA probe specific for H-2K genes, we isolated a class I gene displaying all of the distinctive features of a genuine H-2K gene, and which could thus be defined as an H-2Kw28 gene. The H-2Kw28 gene is 92-95% homologous to H-2Kb and H-2Kd genes and differs significantly from the other class I genes sequenced so far. Homology with the H-2Kb sequence reaches nearly 100% in the 3' part of the H-2Kw28 gene. Moreover, the homology with an H-2Kq cDNA sequence reaches 99.8%. Several hypotheses can account for the near identity of H-2Kb, H-2Kq, and H-2Kw28 gene sequences: either recombination between H-2w28 and H-2b and H-2q sequences occurred before or at the time the strain was established, or the class I genes of the tw32 chromosome and the H-2b and H-2q genes found in inbred strains of mice have separated from each other rather recently.

Amino Acid Sequence↗