Biomedical subjects

B H Toh

Publications and source records attributed to B H Toh.

At least 73 records · Page 4Linked to original sources

PubMed1995

A novel method for isolating mononuclear cells from the stomachs of mice with experimental autoimmune gastritis.

Autoimmune gastritis induced in BALB/c mice by neonatal thymectomy is a CD4+ T cell-mediated disease. The disease is characterised by mononuclear cell infiltrates in the gastric mucosa, loss of gastric parietal and chief cells and autoantibodies to the gastric H/K ATPase. Here we describe a simple non-enzymatic method for isolating cellular infiltrates from stomachs of gastric mice by injection of medium directly into stomach walls, causing swelling and rupture. Using this method, large numbers of viable lymphocytes were released from stomachs for analysis by flow cytometry. An 8.3 fold increase in the total number of lymphocytes from diseased stomachs compared to normal controls was observed. Total cell numbers of CD4+ and B cells were increased 4.8 fold and 39.5 fold respectively, in diseased stomachs compared with controls. No change was observed in the CD8+ T cell population. This method will allow detailed quantitative analysis of cellular infiltrates during the development of the gastric lesion and enrichment of pathogenic T cells for analysis and cloning. This procedure may have general application for the isolation of cellular infiltrates from lesion sites of other organs.

Animals↗

PubMed1994

A new chromosomal protein essential for mitotic spindle assembly.

Assembly of the mitotic spindle, the machinery responsible for chromosomal segregation, is regulated by Cdc2 kinase and requires mitotic chromatin. However, the molecular identity of the kinase substrate and chromatin factor is unknown. Here we have cloned a human complementary DNA encoding an evolutionarily conserved chromosomal protein of relative molecular mass 47,000 (M(r) 47K) which has three consensus motifs for Cdc2 kinase-mediated phosphorylation. The protein is phosphorylated only during mitosis and is associated with polypeptides having M(r)s of 31K, 67K and 200K. Mitotic arrest is induced by antisense messenger RNA or by affinity-purified autoantibody. In the arrested cells, the chromosomes remain unsegregated and the mitotic spindle is absent. We propose that the chromosomal protein is activated by phosphorylation at the interphase/mitosis transition by Cdc2 kinase, and that the protein, alone or as a complex, is a previously unidentified Cdc2 kinase substrate and chromatin factor necessary for spindle assembly.

3T3 Cells↗

PubMed1994

Heterogeneity of human anti-Golgi auto-antibodies: reactivity with components from 35 to 260 kDa.

The Golgi auto-antigens recognized by five human autoimmune sera were characterized with anti-Golgi auto-antibodies. The five sera showed strong anti-Golgi reactivity, together with weak anti-nuclear reactivity, as assessed by indirect immunofluorescence using the human HEp2 epithelial cell line. The Golgi auto-antigens recognized by the autoimmune sera were identified by immunoprecipitation and immunoblotting of post-nuclear supernatants. These sera reacted with at least 14 components of molecular mass (M(r)) 35-260 kDa; three components were detected only by immunoprecipitation, six components detected only by immunoblotting and five components appear to be detected by both techniques. We have previously shown that a patient with Sjögren's syndrome has auto-antibodies specific for a 230 kDa Golgi auto-antigens; a bacterial fusion protein containing auto-epitope(s) of this Golgi auto-antigen is not recognized by the other four autoimmune sera. Taken together, this study shows that the five anti-Golgi autoimmune sera recognize distinct sets of auto-antigens which include both conformational and/or sequential epitopes.

Autoantibodies↗

PubMed1994

A homologue of the human regulator of mitotic spindle assembly protein (RMSA-1) is present in crane fly and is associated with meiotic chromosomes.

In a previous study, we have shown that a newly identified chromosomal protein, RMSA-1 (Regulator of Mitotic Spindle Assembly-1), identified and cloned using a human autoimmune, serum, is essential for mitotic spindle assembly; we proposed that RMSA-1 was a previously unknown physiological substrate for cdc 2 kinase. In the present study, we show that this protein is present in crane fly and is associated with the chromosomes of spermatocytes. A 31 kDa molecule in extracts from crane-fly nuclei, isolated from larvae, pupae and adults, reacts with affinity-purified anti-RMSA-1 autoantibody, shown by immunoblotting. The autoantibody reacts, as shown by immunofluorescence, with crane-fly spermatocyte chromosomes in prophase through anaphase of both meiosis-1 and meiosis-II but does not react with preprophase or telophase nuclei or with spermatid nuclei. In all meiotic stages, the crane-fly sex chromosomes stain more intensely than the autosomes. We conclude that, since RMSA-1 is present in insect and mammalian cells, it is conserved across a variety of animal species. Further, since RMSA-1 binds to chromosomes in meiotic cells, it also may be essential for assembly of the meiotic spindle.

Animals↗

PubMed1994

Cell cycle-associated autoantibodies: markers for autoimmunity and probes for molecular cell biology.

Antinuclear autoantibodies are useful diagnostic markers for systemic autoimmune diseases and as probes for the molecular cell biology of nuclear proteins. Here, we review a subset of autoantibodies to nuclear and cytoplasmic proteins involved in the cell cycle. We propose a classification of these autoantibodies into S-phase (DNA Synthesis) and M-phase (Mitosis) autoantibodies. S-phase autoantibodies are represented by autoantibodies to PCNA (Proliferating Cell Nuclear Antigen), the auxiliary protein of DNA polymerase delta. M-phase autoantibodies are represented by autoantibodies to mitotic spindle components viz. centrosomes, condensed chromosomes, centromeres, mitotic spindle proper and intercellular bridge. We have included autoantibodies to nuclear lamins as M-phase autoantibodies as lamins play a key role in reversible breakdown and reformation of nuclear membranes during mitosis. The usefulness of these autoantibodies as diagnostic markers in systemic autoimmune disease is tempered by their presence in patients with "atypical" autoimmune diseases and in normal individuals. However, as molecular probes, they have proven to be unique and invaluable tools for shedding new light on the workings of the cell cycle.

Animals↗

PubMed1993

An autoimmune disease with multiple molecular targets abrogated by the transgenic expression of a single autoantigen in the thymus.

Many autoimmune diseases are characterized by autoantibody reactivities to multiple cellular antigens. Autoantigens are commonly defined as targets of the autoimmune B cell response, but the role, if any, of these autoantigens in T cell-mediated autoimmune diseases is generally unknown. Murine experimental autoimmune gastritis is a CD4+ T cell-mediated organ-specific autoimmune disease induced by neonatal thymectomy of BALB/c mice. The murine disease is similar to human autoimmune gastritis and pernicious anemia, and is characterized by parietal and chief cell loss, submucosal mononuclear cell infiltrates, and autoantibodies to the alpha and beta subunits of the gastric H/K ATPase. However, the specificity of T cells that cause the disease is not known. To examine the role of the H/K ATPase in this T cell-mediated disease, transgenic mice were generated that express the beta subunit of the H/K ATPase under the control of the major histocompatibility complex class II I-Ek alpha promoter. We show that transgenic expression of the gastric H/K ATPase beta subunit specifically prevents the onset of autoimmune gastritis after neonatal thymectomy. In addition, thymocyte transfer experiments suggest that tolerance of pathogenic autoreactive T cells is induced within the thymus of the transgenic mice. We conclude that the beta subunit of the gastric H/K ATPase is a major T cell target in autoimmune gastritis and that thymic expression of a single autoantigen can abrogate an autoimmune response to multiple autoantigens.

Animals↗

PubMed1993

Gastric parietal cell development: expression of the H+/K+ ATPase subunits coincides with the biogenesis of the secretory membranes.

The early development of the parietal cell in the embryonic murine gastric mucosa was investigated with particular attention paid to the biogenesis of the secretory membranes and the localization of the gastric H+/K+ ATPase alpha and beta subunits. Gastric glands were recognized in the day 18 foetus. However, at this stage in development no parietal cells could be distinguished ultrastructurally in the glands, and no immunoreactivity was detected with monoclonal antibodies to either the alpha or beta subunits of the gastric H+/K+ ATPase. In the 19 day embryo, parietal cells were recognizable morphologically by the presence of slender microvilli on the apical (lumenal) surface and differentiating intracellular canaliculi in the apical cytoplasm. Both subunits of the proton pump were found to be specifically associated with the apical and canalicular membranes and with the membranes of relatively large vesicles distributed in the subapical cytoplasm and the cytoplasm surrounding the canaliculi. In the parietal cells of the day 1 neonate, the intracellular canaliculi had extended basally to form the extensive compartments typical of parietal cells in the adult animal. Again, profiles of vesicles showing H+/K+ ATPase immunoreactivity were present in the pericanalicular cytoplasm. These results indicate that the intracellular canaliculi are formed by expansion of the apical surface and suggest that the delivery of newly synthesized gastric H+/K+ ATPase alpha and beta subunits to the apical plasma membrane is mediated by typical Golgi transport vesicles. The large immunoreactive vesicles that occur in the apical and pericanalicular cytoplasm of the developing cells may represent artefacts generated by fixation-induced fragmentation of the differentiating canalicular membrane system during preparation.

Animals↗

PubMed1993

Alpha and beta subunits of the gastric H+/K(+)-ATPase are concordantly targeted by parietal cell autoantibodies associated with autoimmune gastritis.

We have previously shown that parietal cell autoantibodies predominantly react with a 60-90 kDa gastric autoantigen, subsequently identified as the beta subunit of the gastric H+/K(+)-ATPase (EC 3.6.1.3) (proton pump) whereas Karlsson et al showed that these autoantibodies primarily target the 95 kDa alpha subunit of the pump. In view of these discordant results, we have reassessed the reactivity of parietal cell autoantibodies with the two subunits of the gastric H+/K(+)-ATPase. We show here that all 26 parietal cell autoantibody-positive sera immunoblot both subunits under appropriate, but mutually exclusive, conditions. Thus, reactivity of anti-parietal cell autoantibodies with the 95 kDa alpha subunit is optimal when the SDS-PAGE is carried out with samples which are reduced but not boiled. Whereas reactivity with the 60-90 kDa beta subunit is optimal with samples which are boiled but not reduced. Autoantibody reactivity with the beta subunit is critically dependent on the presence of a full complement of N-linked glycans since partially deglycosylated protein, and recombinant beta subunit expressed in COS cells, bearing high mannose N-glycans, failed to bind to the autoantibody. These studies also suggest that B cell auto-epitopes are located on the lumenal domain of the beta subunit. Reactivity of parietal cell autoantibodies with a bacterial fusion protein incorporating the catalytic cytoplasmic domain of the alpha subunit suggests the presence of auto-epitopes in this region of the molecule.

Animals↗

PubMed1992

Human autoantibodies as reagents to conserved Golgi components. Characterization of a peripheral, 230-kDa compartment-specific Golgi protein.

We have used a serum from a patient with Sjögren's syndrome containing high titer (100,000) anti-Golgi autoantibodies and lower titer (20,000) anti-nuclear autoantibodies to characterize the Golgi complex. The Sjögren's syndrome serum immunoprecipitated a number of components of molecular mass 35-230 kDa from detergent extracts of [35S]methionine-labeled HeLa cells; at high dilution, the serum precipitated one major 230-kDa component. Using the Sjögren's syndrome serum, cDNA clones encoding the Golgi autoantigen were isolated from a lambda gt11 HeLa cell cDNA library. Autoantibodies from the Sjögren's syndrome serum, affinity purified from a recombinant bacterial fusion protein generated from one of the cDNA clones, showed Golgi staining of human, mouse, and chicken cells by immunofluorescence. The purified autoantibodies immunoprecipitated and immunoblotted a 230-kDa component. A rabbit antiserum raised to the recombinant fusion protein specifically stained the Golgi complex by immunofluorescence and reacted with a 230-kDa protein by immunoprecipitation and immunoblotting. The 230-kDa protein was recovered in both the 100,000 x g sedimentable and soluble fractions in cell lysates and in the aqueous phase of Triton X-114 extracts. The 230-kDa autoantigen was dissociated from the Golgi complex by 15-min brefeldin A treatment, dissociation kinetics similar to that of mannosidase II. However, unlike mannosidase II, autoantigen staining was markedly reduced after drug treatment. Removal of brefeldin A resulted in reassociation of the autoantigen with the Golgi complex. The epitopes recognized by the affinity purified human and rabbit antibodies were ultrastructurally localized to the cytosolic face of one side of the Golgi stack, probably the trans-face. Taken together, the 230-kDa protein is a conserved, peripheral membrane component specifically associated with one Golgi compartment. We suggest that this peripheral Golgi protein may have a role in the compartment-specific structural organization of the Golgi or in sorting and transport of proteins.

3T3 Cells↗

PubMed1992

Rapid purification of the gastric H+/K(+)-ATPase complex by tomato-lectin affinity chromatography.

We have previously shown that tomato lectin binds specifically to the 60-90 kDa membrane glycoprotein of parietal cell tubulovesicles, the beta-subunit of the gastric H+/K(+)-ATPase (proton pump) [Callaghan, Toh, Pettitt, Humphris & Gleeson (1990) J. Cell Sci. 95, 563-576; Toh, Gleeson, Simpson, Mortiz, Callaghan, Goldkorn, Jones, Martinelli, Mu, Humphris, Pettitt, Mori, Masuda, Sobieszczuk, Weinstock, Mantamadiotis & Baldwin (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 6418-6422]. Here we have exploited this interaction for the development of a rapid single-step chromatography procedure for the purification of an active pig gastric proton pump complex. Initially, H+/K(+)-ATPase-enriched membranes, prepared from pig gastric microsomes by density-gradient centrifugation, were extracted in 1% Triton X-100 and passed through a 1 ml tomato lectin-Sepharose 4B column. The bound material, eluted with 20 mM-chitotriose, showed a major band with an apparent molecular mass of 95 kDa, and a faint broad band of 60-90 kDa, by SDS/PAGE. N-Glycanase treatment of the bound material resulted in the appearance of a 35 kDa band, the size of the protein core of the 60-90 kDa glycoprotein beta-subunit. The two components were identified as the 95 kDa alpha-subunit and the 60-90 kDa beta-subunit of the gastric H+/K(+)-ATPase, by immunoreactivity with monospecific antibodies, and by tryptic peptide sequences of the tomato-lectin-bound material. The beta-subunit was present in approximately equimolar amounts to the catalytic alpha-subunit. Whereas the gastric H+/K(+)-ATPase was not active after solubilization in 1% Triton X-100, solubilization of density-gradient-purified membranes in the non-ionic detergent, C12E8, followed by chromatography of the extract on tomato lectin-Sepharose 4B, resulted in the purification of the gastric H+/K(+)-ATPase complex which exhibited K(+)-dependent phosphatase activity. This is the first report of a rapid purification of a partially active solubilized gastric H+/K(+)-ATPase complex.

Adenosine Triphosphatases↗

PubMed1992

The mouse gastric H,K-ATPase beta subunit. Gene structure and co-ordinate expression with the alpha subunit during ontogeny.

The gastric H,K-ATPase (EC 3.6.1.3) is responsible for acid secretion into the stomach and is composed of two subunits, alpha and beta. The structure of the gene encoding the mouse beta subunit and the expression of both subunits during ontogeny are reported. The gene spans approximately 12 kilobase pairs and contains 7 exons. The positions at which introns interrupt the coding regions of the mouse H,K-ATPase beta subunit and mouse Na,K-ATPase (EC 3.6.1.37) beta 2 subunit genes are identical. The alternative beta subunit isoform of the Na,K-ATPase, beta 1, has a similar but not identical gene structure. Primer extension and S1 nuclease analysis of RNA isolated from mouse stomachs aged between 2 and 25 days indicated that major transcription-initiation sites are between 22 and 25 base pairs 5' of the translation initiation site at all ages. The expression of the H,K-ATPase alpha and beta subunit genes during ontogeny (day 1-40) was found to be co-ordinated. Protein levels of both the ATPase alpha and beta subunits were very low until day 15 and then increased to adult levels by day 30. In any mucosal cell throughout ontogeny, expression of the beta subunit gene invariably coincided with the expression of the alpha subunit gene. Cells detected by anti-H,K-ATPase beta subunit antibodies in sections from 10- and 30-day-old mice all had typical morphology of parietal cells and were arranged in glandular structures. Co-ordinate expression of the two subunit genes suggest that the regulatory mechanisms will be similar and that the beta subunit may be required for localization and function of the catalytic alpha subunit.

Adenosine Triphosphatases↗

PubMed1992

Autoimmune gastritis: tolerance and autoimmunity to the gastric H+/K+ ATPase (proton pump).

The alpha and beta subunits of the gastric H+/K(+)-ATPase (proton pump) have been identified as the major molecular targets of parietal cell autoantibodies associated with pernicious anaemia and with murine experimental autoimmune gastritis (EAG) induced by neonatal thymectomy. Recent studies with EAG suggest that the mechanisms of peripheral tolerance and autoimmunity to extrathymic autoantigens are mediated by subsets of "regulator" and "effector" CD4+ T cells, respectively. The persistence of "effector" CD4+ autoreactive T cells in the periphery may be a direct consequence of the delayed developmental expression of the target autoantigen. We hypothesize that cytokines produced by the "regulator" T cells prevent the clonal expansion of the "effector" autoreactive T cells, and that neonatal thymectomy induces organ-specific autoimmunity in genetically susceptible individuals by the reduction of the "regulator" T cell population.

Animals↗

PubMed1992

Diagnostic ELISA for parietal cell autoantibody using tomato lectin-purified gastric H+/K(+)-ATPase (proton pump).

Circulating parietal cell autoantibodies, a useful diagnostic marker for autoimmune gastritis and pernicious anaemia, are currently routinely tested by serum immunofluorescence reactivity with frozen sections of rodent stomach. The major molecular targets of these parietal cell autoantibodies have recently been demonstrated to be the alpha- and the beta-subunits of the gastric H+/K(+)-ATPase (proton pump). We have demonstrated that tomato lectin binds specifically to the beta-subunit of the proton pump and concomittantly co-purifies the alpha-subunit. In the present study, we have exploited the latter observation for the development of a diagnostic ELISA for the detection of parietal cell autoantibodies and compared the performance of this assay with an ELISA using crude gastric membranes. The ELISAs were tested on 72 parietal cell autoantibody-positive sera, 72 parietal cell autoantibody-negative sera and 72 disease-control sera. The ELISA using lectin-purified canine proton pump was superior to that using crude canine gastric membranes in that it was about two-fold more sensitive (82% vs. 43%). With an assay sensitivity of 82% and a specificity of 90%, we propose that the ELISA using the lectin-purified proton pump is a rapid, simple, sensitive and specific diagnostic immunoassay for parietal cell autoantibodies.

Autoantibodies↗

PubMed1991

Reverse immunoaffinity chromatography: application to the purification of the 60- to 90-kDa gastric parietal cell autoantigen associated with autoimmune gastritis.

Previous attempts to purify autoantigens by affinity chromatography using the total IgG from autoantibody-positive sera have not been very successful. We describe here a novel method using parietal cell autoantibodies, isolated on a crude autoantigen immunoabsorbent column, for the purification of the 60- to 90-kDa gastric parietal cell antigen targeted in autoimmune gastritis. The 60- to 90-kDa parietal cell antigen was first enriched 2.5-fold from a 0.5% Triton X-100 extract of total pig gastric mucosal membranes by DEAE-Sepharose 4B chromatography. The fraction containing the 60- to 90-kDa antigen was directly coupled to CNBr-activated Sepharose 4B to produce an immunoadsorbent column for the "reverse" purification of the specific parietal cell autoantibodies from pooled gastric parietal cell autoantibody-positive human sera. A 0.5% Triton X-100 extract of pig gastric mucosal membranes was initially precleared by sequential passage through Protein A-Sepharose 4B and normal human Ig-Sepharose 4B columns. The 60- to 90-kDa gastric parietal cell antigen (approximately 10 micrograms) was then purified from this precleared Triton X-100 membrane extract by affinity chromatography on a 1-ml column of purified autoantibody-Sepharose 4B, followed by preparative sodium dodecyl sulfate-polyacrylamide gel electrophonesis. This method, incorporating a "reverse" immunoaffinity chromatography step, has general applicability for the purification of tissue autoantigens using highly specific autoantibodies present in the sera of humans and experimental animals with a variety of other autoimmune diseases.

Animals↗

PubMed1991

Monoclonal antibodies specific for the core protein of the beta-subunit of the gastric proton pump (H+/K+ ATPase). An autoantigen targetted in pernicious anaemia.

The gastric H+/K(+)-transporting adenosine triphosphatase (H+/K+ ATPase) (proton pump) consists of a catalytic alpha-subunit and a recently proposed 60-90-kDa glycoprotein beta-subunit. Using dog gastric membranes as the antigen, we have produced two murine monoclonal antibodies, 4F11 (IgG1) and 3A6 (IgA), which are specific for the 60-90-kDa glycoprotein. The monoclonal antibodies (1) specifically stained the cytoplasm of unfixed and formalin-fixed dog gastric parietal cells; (2) specifically reacted by ELISA with gastric tubulovesicular membranes; (3) recognised epitopes located on the luminal face of parietal cell tubulovesicular membranes, the site of the proton pump, by immunogold electron microscopy; (4) immunoblotted a 60-90-kDa molecule from tubulovesicular membranes and a 35-kDa component from peptide N-glycosidase-F-treated membrane extracts; (5) immunoblotted the 60-90-kDa parietal cell autoantigen associated with autoimmune gastritis and pernicious anemia, purified by chromatography on parietal cell autoantibody- or tomato-lectin-Sepharose 4B affinity columns, and the 35-kDa protein core of this autoantigen; this autoantigen has amino acid sequence similarity to the beta-subunit of the related Na+/K(+)-transporting adenosine triphosphatase (Na+/K+ ATPase) [Toh et al. (1990) Proc. Natl Acad. Sci. 87, 6418-6422]; (6) co-precipitated a molecule of 95 kDa with the 60-90-kDa molecule from 125I-labelled detergent extracts of dog tubulovesicular membranes; and (7) co-purified the catalytic alpha-subunit of the H+/K+ ATPase with the 60-90-kDa molecule by immunoaffinity chromatography of tubulovesicular membrane extracts on a monoclonal antibody 3A6-Sepharose 4B column, indicating a physical association between the two molecules. These results provide further evidence that the 60-90-kDa glycoprotein is the beta-subunit of the gastric H+/K+ ATPase. We conclude that the monoclonal antibodies specifically recognise luminal epitopes on the 35-kDa core protein of the 60-90-kDa beta-subunit of the gastric proton pump, a major target molecule in autoimmune gastritis and pernicious anaemia. These monoclonal antibodies will be valuable probes to study the structure and function of this associated beta-subunit, as well as the ontogeny of the gastric proton pump.

Adenosine Triphosphatases↗

PubMed1991

The parietal cell autoantigens recognized in neonatal thymectomy-induced murine gastritis are the alpha and beta subunits of the gastric proton pump [corrected].

Murine autoimmune gastritis, induced by neonatal thymectomy, bears a striking similarity in pathology to the human autoimmune disease, pernicious anemia. Autoantibodies to parietal cells are found in both murine and human diseases. Monoclonal immunoglobulin G autoantibodies, obtained from neonatally thymectomized mice, have previously been shown to recognize two groups of gastric parietal cell antigens. In the present study, it is shown that two of these monoclonal autoantibodies, designated 1H9 and 2B6, are directed against the alpha subunit and beta subunit, respectively, of the gastric hydrogen-potassium-stimulated adenosine triphosphatase (H+,K(+)-ATPase; proton pump). Monoclonal antibody 1H9 showed reactivity by immunoblotting with a 95-kilodalton component of dog gastric tubulovesicular membranes and with a fusion protein containing the hydrophilic domain of the alpha subunit of the H+,K(+)-ATPase. Monoclonal antibody 2B6 reacted by immunoblotting with the 60-90-kilodalton glycoprotein (beta subunit) of the tomato lectin-purified dog H+,K(+)-ATPase and with the 60-90-kilodalton autoantigen purified with human parietal cell autoantibodies. Monoclonal antibody 2B6 also reacted with the deglycosylated 35-kilodalton core protein of the tomato lectin-purified 60-90-kilodalton beta subunit and of the purified 60-90-kilodalton autoantigen. Parietal cell autoantibody-positive sera from 20 mice with experimentally induced gastritis showed reactivity predominantly with the alpha and/or beta subunit of the gastric H+,K(+)-ATPase. Therefore, it is concluded that the major molecules targeted by parietal cell autoantibodies from mice with neonatal thymectomy-induced murine autoimmune gastritis and from humans with pernicious anemia are identical.

Adenosine Triphosphatases↗

PubMed1991

Molecular targets in pernicious anaemia.

Autoimmune gastritis, leading to pernicious anaemia, is an organ-specific autoimmune disease characterized by chronic atrophic gastritis and circulating gastric parietal cell autoantibodies. The parietal cell autoantigens have recently been identified as the alpha and beta subunit of the gastric proton pump (H+, K+ ATPase). Here Paul Gleeson and Ban-Hock Toh discuss how the identification of these gastric parietal cell autoantigens and the development of a mouse model of autoimmune gastritis have paved the way for an understanding of the pathogenesis of the gastric lesion.

Anemia, Pernicious↗

PubMed1991

T cell receptor and immunoglobulin gene rearrangement analysis as a laboratory aid in the diagnosis of human malignant lymphoproliferative diseases.

The identification of clonal rearrangements of the immunoglobulin heavy chain and T cell receptor beta chain gene loci by Southern blot analysis has led to advances in the diagnosis and classification of lymphoproliferative disorders. This paper reviews our experience with this technique over a three and a half year period. Specimens from 99 patients with suspected haematological malignancy were tested for leucocyte immunophenotype and immunoglobulin or T cell receptor gene rearrangement. Genotyping provided evidence of clonality in malignancies from 28 patients and demonstrated malignant cell lineage in eight patients not formally deduced from immunophenotyping alone. Our findings suggest that this technique can be employed in conjunction with immunophenotyping to aid in the determination of malignant cell lineage derivation and identification of malignant cell clonality, as well as potentially estimating the extent of disease, detecting relapse, and monitoring disease progression.

Gene Rearrangement↗