Enzyme-mediated depletion of methylthioadenosine restores T cell function in MTAP-deficient tumors and reverses immunotherapy resistance

Chromosomal region 9p21 containing tumor suppressors CDKN2A/B and methylthioadenosine phosphorylase (MTAP) is one of the most frequent genetic deletions in cancer. 9p21 loss is correlated with reduced tumor-infiltrating lymphocytes (TILs) and resistance to immune checkpoint inhibitor (ICI) therapy. Previously thought to be caused by CDKN2A/B loss, we now show that it is loss of MTAP that leads to poor outcomes on ICI therapy and reduced TIL density. MTAP loss causes accumulation of methylthioadenosine (MTA) both intracellularly and extracellularly and profoundly impairs T cell function via the inhibition of protein arginine methyltransferase 5 (PRMT5) and by adenosine receptor agonism. Administration of MTA-depleting enzymes reverses this immunosuppressive effect, increasing TILs and drastically impairing tumor growth and importantly, synergizes well with ICI therapy. As several studies have shown ICI resistance in 9p21/MTAP null/low patients, we propose that MTA degrading therapeutics may have substantial therapeutic benefit in these patients by enhancing ICI effectiveness.

Bypassing evolutionary dead ends and switching the rate-limiting step of a human immunotherapeutic enzyme

The Trp metabolite kynurenine (KYN) accumulates in numerous solid tumours and mediates potent immunosuppression. Bacterial kynureninases (KYNases), which preferentially degrade kynurenine, can relieve immunosuppression in multiple cancer models, but immunogenicity concerns preclude their clinical use, while the human enzyme (HsKYNase) has very low activity for kynurenine and shows no therapeutic effect. Using fitness selections, we evolved a HsKYNase variant with 27-fold higher activity, beyond which exploration of >30 evolutionary trajectories involving the interrogation of >109 variants led to no further improvements. Introduction of two amino acid substitutions conserved in bacterial KYNases reduced enzyme fitness but potentiated rapid evolution of variants with ~500-fold improved activity and reversed substrate specificity, resulting in an enzyme capable of mediating strong anti-tumour effects in mice. Pre-steady-state kinetics revealed a switch in rate-determining step attributable to changes in both enzyme structure and conformational dynamics. Apart from its clinical significance, our work highlights how rationally designed substitutions can potentiate trajectories that overcome barriers in protein evolution.

Influenza vaccination in the elderly boosts antibodies against conserved viral proteins and egg-produced glycans

Seasonal influenza vaccination elicits a diminished adaptive immune response in the elderly, and the mechanisms of immunosenescence are not fully understood. Using Ig-Seq, we found a marked increase with age in the prevalence of cross-reactive (CR) serum antibodies that recognize both the H1N1 (vaccine-H1) and H3N2 (vaccine-H3) components of an egg-produced split influenza vaccine. CR antibodies accounted for 73% ± 18% of the serum vaccine responses in a cohort of elderly donors, 65% ± 15% in late middle-aged donors, and only 13% ± 5% in persons under 35 years of age. The antibody response to non-HA antigens was boosted by vaccination. Recombinant expression of 19 vaccine-H1+H3 CR serum monoclonal antibodies (s-mAbs) revealed that they predominantly bound to non-HA influenza proteins. A sizable fraction of vaccine-H1+H3 CR s-mAbs recognized with high affinity the sulfated glycans, in particular sulfated type 2 N-acetyllactosamine (Galβ1-4GalNAcβ), which is found on egg-produced proteins and thus unlikely to contribute to protection against influenza infection in humans. Antibodies against sulfated glycans in egg-produced vaccine had been identified in animals but were not previously characterized in humans. Collectively, our results provide a quantitative basis for how repeated exposure to split influenza vaccine correlates with unintended focusing of serum antibody responses to non-HA antigens that may result in suboptimal immunity against influenza.

Prevalent, protective, and convergent IgG recognition of SARS-CoV-2 non-RBD spike epitopes

The molecular composition and binding epitopes of the immunoglobulin G (IgG) antibodies that circulate in blood plasma after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are unknown. Proteomic deconvolution of the IgG repertoire to the spike glycoprotein in convalescent subjects revealed that the response is directed predominantly (>80%) against epitopes residing outside the receptor binding domain (RBD). In one subject, just four IgG lineages accounted for 93.5% of the response, including an amino (N)-terminal domain (NTD)-directed antibody that was protective against lethal viral challenge. Genetic, structural, and functional characterization of a multidonor class of "public" antibodies revealed an NTD epitope that is recurrently mutated among emerging SARS-CoV-2 variants of concern. These data show that "public" NTD-directed and other non-RBD plasma antibodies are prevalent and have implications for SARS-CoV-2 protection and antibody escape.

Intentional Stent Stenosis to Prevent Hyperperfusion Syndrome after Carotid Artery Stenting for Extremely High-Grade Stenosis

BACKGROUND AND PURPOSE

Intracranial hemorrhage due to hyperperfusion syndrome is a severe carotid artery stent placement complication of extremely high-grade stenosis, causing hemodynamic insufficiency. To prevent hyperperfusion syndrome, we attempted intentional residual stent stenosis and implemented "gentle" carotid artery stent placement, defined as carotid artery stent placement using a closed-cell stent coupled with slight balloon predilation, without balloon postdilation. Gradual stent expansion was expected. We investigated the incidence of hyperperfusion syndrome and long-term outcomes after gentle carotid artery stent placement.

MATERIALS AND METHODS

We included patients who underwent carotid artery stent placement for extremely high-grade stenosis from January 2015 to March 2019. We defined extremely high-grade stenosis as carotid stenosis with conventional angiographic "slow flow" and a reduced MCA signal intensity on MRA. A reduced MCA signal intensity was defined as MCA with a relative signal intensity of <0.9 in the ipsilateral compared with the contralateral MCA. We evaluated the stent diameter, CBF on SPECT, hyperperfusion syndrome, and intracranial hemorrhage. We defined hyperperfusion syndrome as a triad of ipsilateral headache, seizure, and hemiparesis.

RESULTS

Twenty-eight of the 191 patients met our inclusion criteria. After carotid artery stent placement, their median minimal stent diameter was 2.9 mm, which expanded to 3.9 mm at 4 months. Neither cerebral hyperperfusion syndrome nor intracranial hemorrhage occurred.

CONCLUSIONS

The gentle carotid artery stent placement strategy for intentional residual stent stenosis may prevent hyperperfusion syndrome in high-risk patients. Stents spontaneously dilated in 4 months.

Prevalent, protective, and convergent IgG recognition of SARS-CoV-2 non-RBD spike epitopes in COVID-19 convalescent plasma

Although humoral immunity is essential for control of SARS-CoV-2, the molecular composition, binding epitopes and effector functions of the immunoglobulin G (IgG) antibodies that circulate in blood plasma following infection are unknown. Proteomic deconvolution of the circulating IgG repertoire (Ig-Seq ¹ ) to the spike ectodomain (S-ECD ² ) in four convalescent study subjects revealed that the plasma response is oligoclonal and directed predominantly (>80%) to S-ECD epitopes that lie outside the receptor binding domain (RBD). When comparing antibodies directed to either the RBD, the N-terminal domain (NTD) or the S2 subunit (S2) in one subject, just four IgG lineages (1 anti-S2, 2 anti-NTD and 1 anti-RBD) accounted for 93.5% of the repertoire. Although the anti-RBD and one of the anti-NTD antibodies were equally potently neutralizing in vitro , we nonetheless found that the anti-NTD antibody was sufficient for protection to lethal viral challenge, either alone or in combination as a cocktail where it dominated the effect of the other plasma antibodies. We identified in vivo protective plasma anti-NTD antibodies in 3/4 subjects analyzed and discovered a shared class of antibodies targeting the NTD that utilize unmutated or near-germline IGHV1-24, the most electronegative IGHV gene in the human genome. Structural analysis revealed that binding to NTD is dominated by interactions with the heavy chain, accounting for 89% of the entire interfacial area, with germline residues uniquely encoded by IGHV1-24 contributing 20% (149 Å ² ). Together with recent reports of germline IGHV1-24 antibodies isolated by B-cell cloning ^3,4 our data reveal a class of shared IgG antibodies that are readily observed in convalescent plasma and underscore the role of NTD-directed antibodies in protection against SARS-CoV-2 infection.

Carotenoid accumulation in the eyespot apparatus required for phototaxis is independent of chloroplast development in Euglena gracilis

Euglena gracilis exhibits photomovements in response to various light stimuli, such as phototactic and photophobic responses. Our recent study revealed that carotenoids in the eyespot apparatus are required for triggering phototaxis in this alga. However, the role of chloroplasts in eyespot formation is not understood. Here, we isolated carotenoid-less (cl) strains of E. gracilis from cells silenced gene expression of phytoene synthase (EgcrtB). Unlike WT, the culture colors of cl1, cl3, and the non-photosynthetic mutant SM-ZK were orange, while that of cl4 was white. Electron microscope observations showed that SM-ZK, cl1, and cl3 had no developed chloroplast and formed a normal eyespot apparatus, similar to that of WT, but this was not the case for cl4. Carotenoids detected in WT were diadinoxanthin, neoxanthin, and β-carotene. However, the most abundant species of SM-ZK, cl1, and cl3 was zeaxanthin, and there was no diadinoxanthin or neoxanthin. Photomovement analysis showed that SM-ZK, cl1, and cl3 exhibited negative phototactic and photophobic responses, similar to those of WT, whereas cl4 lacked negative phototaxis. Taken together, the formation of the eyespot apparatus required for phototaxis is independent of chloroplast development in E. gracilis, suggesting that this property is different from other photosynthetic flagellates.

Light dependent accumulation of β-carotene enhances photo-acclimation of Euglena gracilis

Carotenoids are essential components of photosynthetic organisms including land plants, algae, cyanobacteria, and photosynthetic bacteria. Although the light-mediated regulation of carotenoid biosynthesis, including the light/dark cycle as well as the dependence of carotenoid biosynthesis-related gene translation on light wavelength, has been investigated in land plants, these aspects have not been studied in microalgae. Here, we investigated carotenoid biosynthesis in Euglena gracilis and found that zeaxanthin accumulates in the dark. The major carotenoid species in E. gracilis, namely β-carotene, neoxanthin, diadinoxanthin and diatoxanthin, accumulated corresponding to the duration of light irradiation under the light/dark cycle, although the translation of carotenoid biosynthesis genes hardly changed. Irradiation with either blue or red-light (3 μmol photons m^-2 s^-1) caused a 1.3-fold increase in β-carotene content compared with the dark control. Blue-light irradiation (300 μmol photons m^-2 s^-1) caused an increase in the cellular content of both zeaxanthin and all trans-diatoxanthin, and this increase was proportional to blue-light intensity. In addition, pre-irradiation with blue-light of 3 or 30 μmol photons m^-2 s^-1 enhanced the photosynthetic activity and tolerance to high-light stress. These findings suggest that the accumulation of β-carotene is regulated by the intensity of light, which may contribute to the acclimation of E. gracilis to the light environment in day night conditions.

One step ultra-high-throughput sequencing of the paired antibody VH:VL and TCRβ:α repertoires using cell lysate resistant xenopolymerase in emulsion

Antibodies and T cell receptors (TCRs) have critical roles in adaptive immunity and thus the determination of their sequences is essential for understanding immune responses in infections or vaccinations, for the discovery of therapeutic antibodies, and for the engineered T cell therapies. Antibodies are composed of variable heavy (VH) and light (VL) chains, and TCRs are composed of variable TCRα/γ and TCRβ/δ chains. Since those chains are encoded by two different transcripts, the determination of functional sequences requires single-cell sequencing. Emulsification of single-cells followed by barcoding of the transcripts or fusion of VH:VL or TCRβ:α transcripts using overlap extension RT-PCR allows high-throughput single-cell sequencing; however, because cell lysate in emulsion inhibits the RT-PCR reaction, these methods require complex microfluidics devices to bypass the inhibition which most of biomedical laboratories cannot access. We discovered recently engineered xenopolymerase, RTX, has an exceptional cell lysate resistance that can overcome this limitation. By employing this unique feature of RTX, we have developed a one-step emulsion-based ultra-high-throughput sequencing method for paired antibody VH:VL and TCRβ:α repertoires not requiring microfluidics or any other specialized equipment. Using this methodology, we obtained high yields (5,000 to &gt;20,000/sample) of paired VH:VL or TCRβ:α clonotypes at low cost. As a demonstration, we applied the methodology to the peripheral blood plasmablasts and T follicular helper (TFH) cells from a seasonal influenza vaccine recipient and discovered high-affinity influenza-specific antibodies and TCRβ:α.

The Force Awakens: Illuminating the Role of Kynurenine in Cancer Progression and Treatment

Cancer is the second leading cause of death in the United States, with an estimated 40% of all Americans expected to be diagnosed with cancer in their lifetime. Despite progress in treatment options, major obstacles in current therapies must be overcome to limit their harmful side effects on patients. To evade immune clearance, many cancers elevate tryptophan (Trp) catabolism in the tumor microenvironment (TME) by upregulating the enzyme indoleamine 2,3-dioxygenase (IDO). As a result, cancer cells (1) monopolize extracellular tryptophan and (2) release L-kynurenine into the TME, an independent immune signal. This change in metabolism generates immune suppression in the TME, but whether the cause arises from Trp depletion or the accumulation of the IDO product kynurenine (L-Kyn) remains highly controversial. Kynurenine is known to induce immunosuppressive phenotypes through aryl hydrocarbon receptor (AhR) activation. However, the functional role of this binding is still poorly understood, despite an explosion of interest and information in the field. Our strategy uses the enzyme kynureninase (KynU) to degrade kynurenine into non-toxic products, thereby restoring anti-tumor immunity without harming the tryptophan metabolism of healthy cells. Moreover, this work aims to determine kynurenine’s molecular effect on T cells to better understand why its depletion successfully relieves tumor burden.

A facile technology for the high-throughput sequencing of the paired VH:VL and TCRβ:TCRα repertoires

Natively paired sequencing (NPS) of B cell receptors [variable heavy (VH) and light (VL)] and T cell receptors (TCRb and TCRa) is essential for the understanding of adaptive immunity in health and disease. Despite many recent technical advances, determining the VH:VL or TCRb:a repertoire with high accuracy and throughput remains challenging. We discovered that the recently engineered xenopolymerase, RTX, is exceptionally resistant to cell lysate inhibition in single-cell emulsion droplets. We capitalized on the characteristics of this enzyme to develop a simple, rapid, and inexpensive in-droplet overlap extension reverse transcription polymerase chain reaction method for NPS not requiring microfluidics or other specialized equipment. Using this technique, we obtained high yields (5000 to >20,000 per sample) of paired VH:VL or TCRb:a clonotypes at low cost. As a demonstration, we performed NPS on peripheral blood plasmablasts and T follicular helper cells following seasonal influenza vaccination and discovered high-affinity influenza-specific antibodies and TCRb:a.

Carotenoids in the eyespot apparatus are required for triggering phototaxis in Euglena gracilis

Carotenoids are the most universal and most widespread pigments in nature. They have played pivotal roles in the evolution of photosensing mechanisms in microbes and of vision in animals. Several groups of phytoflagellates developed a photoreceptive organelle called the eyespot apparatus (EA) consisting of two separable components: the eyespot, a cluster of carotenoid-rich globules that acts as a reflector device, and actual photoreceptors for photobehaviors. Unlike other algal eyespots, the eyespot of Euglenophyta lacks reflective properties and is generally considered to act as a shading device for the photoreceptor (paraflagellar body, PFB) for major photomovements. However, the function of the eyespot of Euglenophyta has not yet been fully proven. Here, we report that the blocking carotenoid biosynthesis in Euglena gracilis by suppressing the phytoene synthase gene (crtB) caused a defect in eyespot function resulting in a loss of phototaxis. Raman spectroscopy and transmission electron microscopy suggested that EgcrtB-suppressed cells formed eyespot globules but had a defect in the accumulation of carotenoids in those packets. Motion analysis revealed the loss of phototaxis in EgcrtB-suppressed cells: a defect in the initiation of turning movements immediately after a change in light direction, rather than a defect in the termination of cell turning at the appropriate position due to a loss of the shading effect on the PFB. This study revealed that carotenoids are essential for light perception by the EA for the initiation of phototactic movement by E. gracilis, suggesting one possible photosensory role of carotenoids in the EA for the phototaxis.

Determinants governing T cell receptor α/β-chain pairing in repertoire formation of identical twins

The T cell repertoire in each individual includes T cell receptors (TCRs) of enormous sequence diversity through the pairing of diverse TCR α- and β-chains, each generated by somatic recombination of paralogous gene segments. Whether the TCR repertoire contributes to susceptibility to infectious or autoimmune diseases in concert with disease-associated major histocompatibility complex (MHC) polymorphisms is unknown. Due to a lack in high-throughput technologies to sequence TCR α-β pairs, current studies on whether the TCR repertoire is shaped by host genetics have so far relied only on single-chain analysis. Using a high-throughput single T cell sequencing technology, we obtained the largest paired TCRαβ dataset so far, comprising 965,523 clonotypes from 15 healthy individuals including 6 monozygotic twin pairs. Public TCR α- and, to a lesser extent, TCR β-chain sequences were common in all individuals. In contrast, sharing of entirely identical TCRαβ amino acid sequences was very infrequent in unrelated individuals, but highly increased in twins, in particular in CD4 memory T cells. Based on nucleotide sequence identity, a subset of these shared clonotypes appeared to be the progeny of T cells that had been generated during fetal development and had persisted for more than 50 y. Additional shared TCRαβ in twins were encoded by different nucleotide sequences, implying that genetic determinants impose structural constraints on thymic selection that favor the selection of TCR α-β pairs with entire sequence identities.

Determinants of TCRα-β chain pairing in generating TCR diversity

Advances in next-generation sequencing have allowed insights into the enormous diversity of the human T cell receptor (TCR). Earlier studies have suggested that ~108 unique TRB genes exist at the periphery. In contrast, the factors that determine the pairing of TCRα and TCRβ chains have remained elusive due to the lack of high-throughput single-cell sequencing technology. We have developed a high-throughput single-cell sequencing technology that enables identification of &gt;3×104 paired TRA:TRB sequences per sample and have conducted sequencing of naïve and memory CD4+ and of total T cells from 15 healthy individuals, including six pairs of monozygotic twins. We found that the frequencies of TRAV:TRBV pairing are essentially determined by the frequencies of the individual gene segments, suggesting the absence of structural constraints in the pairing of the α and β chains. Twins are more similar in the frequencies of TRAV and TRBV combinations than are unrelated individuals, but this difference was explained by a genetic influence on AV and BV gene segment frequencies. Twins and unrelated individuals were compared for the sharing of identical TCR sequences. TRA sequence sharing among twins was comparable to that among unrelated individuals, but TRB sharing was significantly higher in twins. Sharing of the entire TCR was regularly found in twins but not detected for naïve CD4+ T cells from unrelated individuals. Results were similar for naïve and memory T cells, with the genetic influence more prominent in memory T cells, suggesting the additional influence of peripheral selection. In support of this interpretation, the sharing of identical TCR sequences in unrelated individuals correlated with the number of shared MHC class II alleles.

Persistent Antibody Clonotypes Dominate the Serum Response to Influenza over Multiple Years and Repeated Vaccinations

Humans are repeatedly exposed to influenza virus via infections and vaccinations. Understanding how multiple exposures and pre-existing immunity impact antibody responses is essential for vaccine development. Given the recent prevalence of influenza H1N1 A/California/7/2009 (CA09), we examined the clonal composition and dynamics of CA09 hemagglutinin (HA)-reactive IgG repertoire over 5 years in a donor with multiple influenza exposures. The anti-CA09 HA polyclonal response in this donor comprised 24 persistent antibody clonotypes, accounting for 72.6% ± 10.0% of the anti-CA09 HA repertoire over 5 years. These persistent antibodies displayed higher somatic hypermutation relative to transient serum antibodies detected at one time point. Additionally, persistent antibodies predominantly demonstrated cross-reactivity and potent neutralization toward a phylogenetically distant H5N1 A/Vietnam/1203/2004 (VT04) strain, a feature correlated with HA stem recognition. This analysis reveals how "serological imprinting" impacts responses to influenza and suggests that once elicited, cross-reactive antibodies targeting the HA stem can persist for years.

Low Temperature Stress Alters the Expression of Phytoene Desaturase Genes (crtP1 and crtP2) and the ζ-Carotene Desaturase Gene (crtQ) Together with the Cellular Carotenoid Content of Euglena gracilis

Carotenoids participate in photosynthesis and photoprotection in oxygenic phototrophs. Euglena gracilis, a eukaryotic phytoflagellate, synthesizes several carotenoids: β-carotene, neoxanthin, diadinoxanthin and diatoxanthin. Temperature is one of the most striking external stimuli altering carotenoid production. In the present study, to elucidate the regulation of carotenoid synthesis of E. gracilis in response to environmental stimuli, we functionally identified phytoene desaturase genes (crtP1 and crtP2) and the ζ-carotene desaturase gene (crtQ) of this alga and analyzed expression of those genes and the composition of major carotenoids in cells grown under cold (20�C) and high-intensity light (HL; 240 �mol photon m-2 s-1) conditions. 20�C-HL treatment increased the transcriptional level of the phytoene synthase gene (crtB), and crtP1 and crtP2, whose products catalyze the early steps of carotenoid biosynthesis in this alga. Cultivation at 20�C under illumination at 55 �mol photon m-2 s-1 (low-intensity light; LL) decreased the cell concentration, Chl and total major carotenoid content by 61, 75 and 50%, respectively, relative to control (25�C-LL) cells. When grown at 20�C-HL, the cells showed a greater decrease in cell concentration and photosynthetic pigment contents than those in 20�C-LL. β-Carotene, neoxanthin and diadinoxanthin contents were decreased by more than half in 20�C-LL and 20�C-HL treatments. On the other hand, when subjected to 20�C-LL and 20�C-HL, the cells retained a diatoxanthin content comparable with control cells. Our findings suggested that diatoxanthin plays crucial roles in the acclimation to cold and intense light condition. To the best of our knowledge, this is the first report on a photosynthetic organism possessing dual crtP genes.

The Force Awakens: Illuminating the role of kynurenine in cancer progression and treatment

Cancer is the second leading cause of death in the US and, despite progress in treatment options, there is a critical need for novel treatments that specifically target cancerous cells. Our immune system routinely identifies potential cancer cells and eliminates them without the need for clinical intervention. However, to evade immune clearance, many cancers elevate tryptophan catabolism in the tumor microenvironment (TME) by upregulating the enzymes indoleamine 2, 3-dioxygenase (IDO) or, alternatively, tryptophan 2, 3- dioxygenase (TDO). This results in greater tryptophan turnover, accumulation of IDO/TDO product, kynurenine (L-kyn), and immune suppression in the TME. Whether the resulting immunosuppression arises from tryptophan depletion or L-kyn accumulation remains highly controversial. This work aims to (1) clarify L-kyn’s effect on T-cells and (2) whether its depletion can relieve tumor burden. Exposing T cells to L-kyn in vitro results in gene expression changes consistent with regulatory T-cell generation and the suppression of naïve T-cell proliferation; establishing L-kyn as a key therapeutic target for depletion to relieve TME immune suppression. Using a pharmacologically optimized kynureninase (KynU) enzyme, we tested L-kyn depletion therapy in murine cancers. KynU administration potently inhibits tumor growth, reduces L-kyn concentration, and results in a significant increase in the infiltration and proliferation of polyfunctional T-lymphocytes. Our ongoing study of KynU’s efficacy and L-kyn’s in vitro effects will illuminate details of L-kyn’s elusive mechanism of action, resolving critical mechanisms of tumor tolerance while creating a more innovative and effective cancer treatment strategy.

Identification of tumor-reactive B cells and systemic IgG in breast cancer based on clonal frequency in the sentinel lymph node

A better understanding of antitumor immune responses is the key to advancing the field of cancer immunotherapy. Endogenous immunity in cancer patients, such as circulating anticancer antibodies or tumor-reactive B cells, has been historically yet incompletely described. Here, we demonstrate that tumor-draining (sentinel) lymph node (SN) is a rich source for tumor-reactive B cells that give rise to systemic IgG anticancer antibodies circulating in the bloodstream of breast cancer patients. Using a synergistic combination of high-throughput B-cell sequencing and quantitative immunoproteomics, we describe the prospective identification of tumor-reactive SN B cells (based on clonal frequency) and also demonstrate an unequivocal link between affinity-matured expanded B-cell clones in the SN and antitumor IgG in the blood. This technology could facilitate the discovery of antitumor antibody therapeutics and conceivably identify novel tumor antigens. Lastly, these findings highlight the unique and specialized niche the SN can fill in the advancement of cancer immunotherapy.

Clinicopathologic Impact of Early Medullary Ray Injury in Patients Following Kidney Transplantation

BACKGROUND

Previously, we explored the histopathologic characteristics of medullary ray injury (MRI) inducing interstitial fibrosis and tubular atrophy (IF/TA) to determine its etiologies, which include calcineurin inhibitor (CNI) toxicity and urologic complications. However, we did not examine the effects of these etiologies on long-term kidney allograft prognosis, because biopsy timing differed among cases.

AIM

We examined the influence of early MRI on kidney allograft prognosis using protocol biopsies taken within a 3-month time frame.

METHODS

We defined early MRI as tubular degeneration with interstitial edema or mild fibrosis localized to the medullary ray. We divided 53 protocol biopsies into 2 groups, with and without early MRI. Early MRI+ cases with isometric vacuolization were classified as CNI toxicity; those with Tamm-Horsfall protein in the interstitium and a thyroidlike appearance were classified as urinary tract system abnormalities; remaining cases were classified as "others." We compared changes in serum levels of creatinine (sCr) over 3 years and fibrosis extent at 1 year.

RESULTS

The sCr levels were significantly higher in the MRI+ group than the MRI- group at 3 years (P = .024). Examining the 3 MRI+ subgroups, only the MRI+ urinary tract system abnormalities group had significantly high sCr levels compared to the MRI- group (P = .019). The MRI+ group showed significant signs of IF/TA at 1 year.

CONCLUSIONS

Early MRI after kidney transplantation was significantly more likely to develop IF/TA at 1 year and had higher sCr levels at 3 years. In such cases, intervention might preserve graft function over the long term.

Identification of a novel alpha-fetoprotein-expressing cell population induced by the Jagged1/Notch2 signal in murine fibrotic liver

The liver is well known to possess high regenerative capacity in response to partial resection or tissue injury. However, liver regeneration is often impaired in the case of advanced liver fibrosis/cirrhosis when mature hepatocytes can hardly self‐proliferate. Hepatic progenitor cells have been implicated as a source of hepatocytes in regeneration of the fibrotic liver. Although alpha‐fetoprotein (AFP) is known as a clinical marker of progenitor cell induction in injured/fibrotic adult liver, the origin and features of such AFP‐producing cells are not fully understood. Here, we demonstrate a unique and distinct AFP‐expressing cell population that is induced by the Jagged1/Notch2 signal in murine fibrotic liver. Following repeated carbon tetrachloride injections, a significant number of AFP‐positive cells with high proliferative ability were observed along the fibrous septa depending on the extent of liver fibrosis. These AFP‐positive cells exhibited features of immature hepatocytes that were stained positively for hepatocyte‐lineage markers, such as albumin and hepatocyte nuclear factor 4 alpha, and a stem/progenitor cell marker Sox9. A combination of immunohistological examination of fibrotic liver tissues and coculture experiments with primary hepatocytes and hepatic stellate cells indicated that increased Jagged1 expression in activated hepatic stellate cells stimulated Notch2 signaling and up‐regulated AFP expression in adjacent hepatocytes. The mobilization and proliferation of AFP‐positive cells in fibrotic liver were further enhanced after partial hepatectomy, which was significantly suppressed in Jagged1‐conditional knockout mice. Finally, forced expression of the intracellular domain of Notch2 in normal liver induced a small number of AFP‐expressing hepatocytes in vivo. Conclusion: Insight is provided into a novel pathophysiological role of Jagged1/Notch2 signaling in the induction of AFP‐positive cells in fibrotic liver through the interaction between hepatocytes and activated hepatic stellate cells. (Hepatology Communications 2017;1:215‐229)

Successful treatment of monomorphic primary central nervous system post-transplantation lymphoproliferative disorder 5 years after kidney transplantation

A 31-year-old man underwent living-related kidney transplantation in 2004 as a consequence of primary focal segmental glomerulosclerosis (FSGS). Four years after the transplantation, we confirmed nephrotic syndrome caused by recurrent FSGS. We performed plasmapheresis and low-density lipoprotein adsorption. We also combined steroid therapy with a reduction in the dose of tacrolimus and an increased dose of mycophenolate mofetil. The nephrotic syndrome improved dramatically with this combined therapeutic approach. However, 10 months after these treatments, he revisited our hospital because of altered consciousness. We detected multiple tumor masses in his brain that were ring enhanced on contrast magnetic resonance imaging. Consequently, we suspected primary central nervous system post-transplantation lymphoproliferative disorder (CNS-PTLD). We performed a craniotomy to biopsy the brain tumors. The biopsy specimen showed Epstein-Barr virus-associated diffuse large B-cell lymphoma. There is no definitive treatment for CNS-PTLD. Therefore, we treated the primary CNS-PTLD successfully with whole-brain radiation and discontinuation of immunosuppression therapy.

Simple biodosimetry method for use in cases of high-dose radiation exposure that scores the chromosome number of Giemsa-stained drug-induced prematurely condensed chromosomes (PCC)

There is a need for quick dose estimation by a simple method in radiation accidents. This study develops a simple and rapid dose estimation protocol for victims of such accidents, in particular those involving high radiation doses. Human peripheral blood lymphocytes (PBL) were gamma-irradiated in vitro at several dose points up to 60 Gy, and were stimulated with phytohaemagglutinin-P (PHA-P) for 2 days to obtain dividing cells. PBL were then forced to condense prematurely, using 50 nM calyculin A, and the obtained chromosome spreads were Giemsa stained. The G2-PCC (prematurely condensed chromosomes) index and chromosome number for each radiation dose point were scored. G2-PCC were stably induced using calyculin A within 24 h delays in stimulation of PBL with PHA-P. The chromosome number of G2-PCC increased steeply with radiation doses up to 30 Gy at a rate of 0.31 Gy(-1) and then decreased at 0.30 Gy(-1) up to 40 Gy. More than 10% of G2-PCC index remained up to a 15 Gy dose. Even after 40 Gy irradiation, about 2% PCC index was obtained, and this value was enough to score a sufficient number of chromosome spreads for analysis. Therefore, the combined use of chromosome number and G2-PCC index allows biodosimetry to be done easily and rapidly. If PCC are not induced using calyculin A, it is strongly suggested that the radiation dose is over 50 Gy. A rapid and easy dose estimation for large dose exposure whole-body was realized by combined analysis of Giemsa-stained chromosome number of G2-PCC and PCC index using calyculin A. This simple method will be of use for rapid decision making of therapy for radiation accident victims. This method also has potential for use as a biodosimeter for partial-body exposure accidents.

Mitotic arrest caused by an X-ray microbeam in a single cell expressing EGFP-aurora kinase B

Although the highest radiosensitivity of cells in the M phase among the other cell phases, such as the G(1), S and G(2) phases, has been known, the exact mechanism of radiosensitivity in mitotic cells remains unclear. Recently, mitotic arrest caused by DNA-damaging reagents has been shown, and the molecular mechanism in the arrest has been discussed in detail. In this study, abnormal cell-cycle progression in the M phase was investigated when a single mitotic cell in each mitotic stage was irradiated with a 5.35 keV X-ray microbeam focused on the cell nucleus. An X-ray microbeam irradiation system installed at BL-27 in Photon Factory, High Energy Accelerator Research Organization (HEARO, Tsukuba) was used. HeLa cells, genetically modified and expressing enhanced green fluorescent protein-tagged aurora kinase B, were used as irradiated samples in order to recognise the stage of each cell in the M phase. Thus, 10 Gy irradiation concentrated at the nucleus of a single cell elongated the cell-cycle progression in the M phase by delaying the metaphase/anaphase transition. The dose dependence of the elongation of the M phase was also examined. An irregular distribution of DNA in anaphase cells was observed after irradiation.

Simple biodosimetry method for cases of high-dose radiation exposure using the ratio of the longest/shortest length of Giemsa-stained drug-induced prematurely condensed chromosomes (PCC)

The aim was to develop a simple biodosimetry method for as rapid as possible estimation of absorbed radiation doses in victims of radiation accidents, in particular after high-dose exposure. Human peripheral blood lymphocytes (PBL) were gamma-irradiated in vitro with several doses up to 40 Gy stimulated with phytohaemagglutinin-P (PHA-P) for 2 days and their chromosomes condensed prematurely using 50 nm calyculin A. Chromosome lengths of Giemsa-stained G2 prematurely condensed chromosomes (PCC) were measured using image analysing software and the ratio of the longest/shortest chromosome length was calculated. The length ratio (LR) of the longest/shortest Giemsa-stained chromosome s increased with a good correlation to the square root of the radiation dose (D) up to 40 Gy, i.e. LR = (4.90 x D0.5) + 2.14. The LR of the longest/shortest chromosome might be used as an index for estimating the radiation dose. The blood samples should not be cooled until the start of separation/stimulation of the lymphocytes. A rapid and easy estimation of large doses after whole-body exposure was identified by measuring the ratio of the longest/shortest length of Giemsa-stained G2-PCC induced by calyculin A. This simple protocol will be particularly useful for making therapy decisions for victims of ionizing radiation exposure and has potential for use as a biodosimeter for partial-body exposure accidents.

Changes in peripheral lymphocyte subpopulations after direct moxibustion

We measured peripheral lymphocyte subpopulations after direct moxibustion using moxa cones the size of a half-rice grain. In humans at 2 hrs after the direct moxibustion, NK cell percentage decreased and CD4/CD8 ratio increased significantly. Although the same trends were observed in the control session, those changes were not statistically significant. In rabbits at 3 and 12 hrs after direct moxibustion, CD4/CD8 ratio significantly increased, and recovered at between 24 and 72 hrs after treatment. Similarly, the CD4/CD8 ratio significantly increased in the control session, but they seemed to have a shorter duration. Although it is not yet clear whether the effects are beneficial, we found that direct moxibustion influences the immune system at least transiently.

Systematic review of adverse events following acupuncture: the Japanese literature

CONTEXT

Many Japanese cases of adverse events after acupuncture are not listed in medical databases such as Medline. Therefore, they are not easily accessible to researchers outside Japan.

OBJECTIVE

To complement existing reviews of adverse events after acupuncture in the West and to provide more detailed discussion and analysis.

DATA SOURCES

Literature search using 'Igaku Chuo Zasshi (Japana Centra Revuo Medicina) CD-ROM version' covering the period of 1987-1999.

STUDY SELECTION

Case reports of adverse events, which were suspected to be due to acupuncture treatment, were included. Experimental studies, surveys, and news articles were excluded.

DATA EXTRACTION

Two independent reviewers extracted data from located articles in a pre-defined structured way, and assessed likelihood of causality in each individual case.

DATA SYNTHESIS

89 articles which reported 124 cases were located. The most frequent adverse events were: pneumothorax (25 cases), spinal cord injury (18 cases), acute hepatitis B (11 cases), and localized argyria (10 cases). There were two fatalities from infections. Forty-eight events were caused by needle breakage including 26 cases of intentionally embedded needle and 16 cases of accidental breakage. There were also 10 cases of injury from self-treatment.

CONCLUSION

Although it has already been demonstrated that severe adverse events seem to be uncommon in standard practice, many serious cases of negligence have been found in the present review, suggesting that training system for acupuncturists (including medical doctors) should be improved and that unsupervised self-treatment should be discouraged.

Sleep-wake rhythm during stay in an intensive care unit: a week's long-term recording of skin potentials

To monitor the sleep-wake cycle of patients during their stay in the intensive care unit (ICU), we tried continuous and long-term recording of skin potential (SP) levels in patients after surgery. A graph of the week-long SP showed the sleep-wake pattern to be evident until the fourth day. It disappeared beginning on the fifth day, resulting finally in delirium with a relatively high mean SP level. In another record, the administration of sedative agents to calm the excitement lowered the mean SP level and suppressed SP responses evoked by frequent day and night treatment or nursing care. Continuous monitoring of arousal level by SP will be of help in prevention of ICU syndrome.

[Construction of scales to measure thematic tendencies of paranoid ideation]

In order to measure thematic tendencies of paranoid ideation in non-clinical samples, Delusional Ideation Checklist (DICL) was developed. A wide range of items indicating themes of delusion were collected. From the results of factor analysis on the data of 308 college students, eight scales were constructed. They were: alienation, belittlement, persecution, other-harming, guardedness, self-conceit, favoredness, and other-manipulation. These scales could be classified in terms of emotion: positive versus negative, and direction: self versus others, and could deal with themes of paranoid ideation in a comprehensive and systematic way. Alpha coefficients of the scales were between .66 and .87, and test-retest reliability between .49 and .71. To examine content validity, ten psychiatrists were asked to rate diagnostic importance for each scale item. Six scales were rated as significantly more important in the diagnosis of paranoid schizophrenia than that of anxiety neurosis. Current data revealed that ordinary students experienced delusional ideation more frequently than psychiatrists would expect.

Incidence of adverse reactions associated with acupuncture

OBJECTIVES

To determine the type, severity, and incidence of acupuncture adverse reactions that are observed in standard practice.

DESIGN

A survey based on observation and interview by the therapists.

SETTING

Tsukuba College of Technology Clinic in Japan.

SUBJECTS

All patients who underwent acupuncture treatment during a period of 4 months from April to July 1998.

OUTCOME MEASURES

Type, severity, and incidence of acupuncture adverse reactions.

RESULTS

A total of 391 patients were treated in 1,441 sessions, involving a total of 30,338 needle insertions. The incidence of recorded systemic reactions in individual patients was: tiredness (8.2%); drowsiness (2.8%); aggravation of preexisting symptoms (2.8%); itching in the punctured regions (1.0%); dizziness or vertigo (0.8%); feeling of faintness or nausea during treatment (0.8%); headache (0.5%); and chest pain (0.3%). The incidence of recorded local reactions, expressed as a percentage of needle insertions, was: minor bleeding on withdrawal of the needle (2.6%); pain on insertion of the needle (0.7%); petechia or ecchymosis (0.3%); pain or ache in the punctured region after the treatment (0.1%); subcutaneous haematoma (0.1%); and pain or discomfort in the punctured region during the needle retention (0.03%).

CONCLUSION

Although some adverse reactions associated with acupuncture were common even in standard practice, they were transient and mild compared to cases such as pneumothorax, cardiac injury, infection, or spinal lesions reported in other studies.

[Clinical evaluation of cases with massive ascites accumulation after discontinuation of CAPD: an attempt to establish the concept of the pre-sclerosing encapsulating peritonitis(pre-SEP) state]

Sclerosing encapsulating peritonitis(SEP) is a most serious complication of continuous ambulatory peritoneal dialysis(CAPD). Although the criteria of diagnosis and guidelines for therapy of SEP have been proposed by the Japanese SEP Study Group already, SEP is refractory to treatment when the disease process is complete. It is important to detect the latent phase of SEP(pre-SEP state) in order to treat patients at an early stage. We evaluated the characteristics of ascites in four patients with massive ascites accumulation after discontinuation of CAPD. Age and the duration of CAPD of the subjects were 53.3 +/- 9.7 years and 126.5 +/- 6.8 months, respectively. However, the patients were withdrawn from CAPD because of peritonitis or ultrafiltration failure. We also followed cytokines and parameters of collagen metabolism of ascites in two patients during adrenocorticosteroid therapy and conducted a histopathological evaluation of the peritoneum of an autopsy case who had died of pneumonia. Ascites seems to be exudative because of the high concentration of protein, cytokines and parameters of collagen metabolism such as interleukin-1 beta, interleukin-6, transforming growth factor-beta 1, procollagen 3 peptide, and type IV collagen 7S, the levels of which were 21.3 +/- 9.3 pg/ml, 8,153 +/- 7,327 pg/ml, 6.7 +/- 3.6 ng/ml, 89.3 +/- 67.8 U/ml, and 59.0 +/- 36.2 ng/ml, respectively. The histopathological findings of the peritoneum from the autopsy case showed dense fibrous tissue permeated with inflammatory infiltration and widespread infiltration of fibrin. These findings suggested that the peritoneum was inflamed when massive ascites accumulated. The amount of ascites and concentration of cytokines and parameters of collagen metabolism of ascites diminished during adrenocorticosteroid therapy. We concluded that massive and refractory accumulation of ascites appearing after the discontinuation of CAPD should be regarded as a sign of the pre-SEP state, and prophylactic treatment should be started at this stage of disease.

[L-selectin expressed on peripheral monocytes and soluble L-selectin in sera in atopic diseases]

For the purpose of assessing the involvement of L-selectin in atopic diseases, we measured L-selectin expressed on peripheral monocytes and serum soluble L-selectin (sL-selectin). We enrolled 7 patients with atopic bronchial asthma(BA), 6 patients with atopic dermatitis, 12 patients with Japanese cedar pollinosis(P), and 9 healthy controls(C). L-selectin expressed on peripheral monocytes was detected and analyzed by using flow cytometry. Serum sL-selectin was measured by enzyme-linked immunosorbent assay. Compared with the group C (81.7 on average), mean fluorescence intensity of CD 62 L on monocytes in the group BA was significantly higher (110.4 on average, p < 0.05). The group AD also showed higher tendency (101.3 on average, p < 0.08). No significant difference was found in serum sL-selectin levels among the four groups(BA: 1086 ng/mL, AD: 1226 ng/mL, P: 945 ng/mL, C: 1052 ng/mL, on average). There was a negative correlation (r = -0.69) between serum sL-selectin and age in all subjects (BA + AD + P + C). The results suggest that L-selectin is involved in the extravasation of monocytes toward local inflammatory sites in atopic diseases. Serum sL-selectin seems to stay at normal level in mild and stable atopic diseases, while the trend of high serum sL-selectin level in children may participate in the pathogenesis.

Localization of huntingtin-interacting protein-2 (Hip-2) mRNA in the developing mouse brain

Huntingtin-interacting protein-2 (Hip-2) was identified as a human protein specifically associated with huntingtin in vitro, a gene product affected in patients with Huntington disease (HD). It is a ubiquitin-conjugating enzyme identical to the previously characterized bovine E2-25k. We identified the mouse Hip-2 homologue (mHip-2) and examined its distribution patterns in the developing mouse brain in order to gain an insight into the functional significance of the Hip-2 protein in the normal brain as well as in the pathogenesis of HD. As reported with huntingtin, the mHip-2 mRNA expression developed in parallel with neuronal maturation and became distributed widely in the postnatal mouse brain. This spatiotemporal pattern of mHip-2 mRNA expression resembled that of huntingtin. We further demonstrated that mHip-2 mRNA was colocalized with huntingtin-like immunoreactivity in a single neuron. These findings suggested that the Hip-2 interacted with huntingtin in vivo and played an important role in HD pathogenesis.

[Factors influencing residual renal function of CAPD patients]

It is generally accepted that residual renal function has significant meaning in dialysis adequacy of CAPD patients. However, the factors influencing the residual renal function have not been investigated yet. We evaluated the consequences of following factors on residual urine volume in 50 CAPD patients: deterioration rate of renal function (slope of I/serum creatinine) before dialysis, renal creatinine clearance at the initial point of dialysis and the episodes of rapid reduction of residual urine volume. There was no correlation between the deterioration rate of renal function before dialysis and the residual urine volume. On the contrary, there was significant correlation between renal creatinine clearance at the initial point of dialysis and the residual urine volume in the first 4 years on CAPD. We recognized 67 episodes of rapid reduction of residual urine volume after initiation of CAPD. Inappropriate management or complications attributed to the rapid urine volume reduction in 50 episodes. The residual urine volume did not recover to the previous level in 40 episodes. We concluded that early initiation of CAPD and evasion of decreasing residual urine volume caused by inappropriate management or complications have important meaning and will preserve residual renal function of CAPD patients.

Aberrant judgmental pattern of schizophrenic patients in weight discrimination

Sixteen chronic schizophrenics and 16 normal controls were tested on a weight discrimination task in various categories and hand conditions. Schizophrenics made significantly more errors than normals when the 'equal' category was included, whereas schizophrenics' performance could approximate the normals' discriminations when the 'equal' category was excluded. In the former condition, the more inaccurate performance of schizophrenics was ascribed to the selective increase in the errors by the 'equal' judgments, which was not due to an increase in 'doubtful' judgments. These findings were assumed to reflect schizophrenics' preference to equal judgments, which seemed to be their fundamental cognitive attitude, because the same tendency was found on the various discrimination tasks of other sensory modalities. Furthermore, the present results supported neither left hemisphere dysfunction nor interhemispheric transfer deficit in schizophrenia, because schizophrenics failed to show consistently more errors in the right hand and the bimanual conditions.

Expression of sonic hedgehog signal transducers, patched and smoothened, in human basal cell carcinoma

In basal cell nevus syndrome (BCNS) patients, mutations of a gene, patched (ptc), which encodes a putative signal transducer of sonic hedgehog protein (SHH), were found and are thought to be one of the major causes of BCNS. The SHH signaling pathway is an important developmental pathway, and ptc protein (PTC) is a suppressive component serving as a receptor for the secreted SHH. Another transmembrane protein, smoothened (SMO), forms a complex with PTC and regulates this signaling pathway. Recent transgenic studies have strengthened the importance of the SHH signaling system in the etiology of basal cell carcinoma (BCC). In this study, we examined the expression patterns of mRNA for ptc and smo in two different BCC subtypes and normal skin. We found that the expressions of ptc and smo mRNA were enhanced in the tumor nests of the nodular BCC, especially at the advancing portions, but were under the detectable level in the superficial BCC cases examined, indicating that ptc and smo mRNA expressions might be associated with BCC tumor progression and divide the BCC histologic types into two subtypes, superficial and nodular types. In addition, no obvious signals for ptc and smo mRNA were detected in the normal human epidermis, appendages, or seborrheic keratosis, indicating that the abnormal proliferation of follicular epithelial cells caused by ptc, smo and/or other genetic changes, which also cause ptc and smo overexpressions, might result in BCC tumor formation.

The signal detection ability of patients with auditory hallucination: analysis using the continuous performance test

Signal detection theory is appropriate for analyzing the problem of whether auditory hallucination arises from a sensory or judgmental disorder. In the present study the sensory discrimination ability and decision bias of psychiatric patients with auditory hallucination was investigated by using the visual continuous performance test. Based on signal detection theory the d' (d prime) and the lnbeta value (the natural logarithm of the beta value) were calculated. The d' is indicator of discriminating ability, whereas the lnbeta value is an indicator of decision bias. The psychiatric inpatients with the diagnosis of schizophrenia mainly were divided into 11 patients with auditory hallucinations (AH(+)) and 11 patients without hallucinations (AH(-)). As compared with the AH(-) group, the AH(+) group showed the same d' value and a significantly lower lnbeta value. As compared with the normal control group, the AH(+) group showed a significantly lower d' value and a nearly normal lnbeta value. These results suggest that auditory hallucination is characterized by a cognitive deficit of unreasonably maintaining a relatively risk-taking decision bias in spite of decreased discriminating ability, which opposes the interpretation of Bentall and Slade (1985). The AH(+) group was divided into subgroups with bizarre delusions (BD(+)) and without bizarre delusions (BD(-)). The BD(+) group showed a stronger tendency toward a lower d' value and normal lnbeta value, which the AH(+) group had.

Adverse events in acupuncture and moxibustion treatment: a six-year survey at a national clinic in Japan

OBJECTIVES

Many of the frequently reported adverse effects of acupuncture are serious or severe such as pneumothorax, infection, spinal cord injury, or cardiac injury. However, reviewing published case reports does not provide enough information to assess the safety of acupuncture and moxibustion. In order to investigate adverse events of acupuncture, we reviewed all the relevant cases reported by the therapists at our clinic.

SETTING

Over a 6 year period, in the national Tsukuba College of Technology Clinic in Japan, all the acupuncture and moxibustion therapists were required to report the cases of adverse events immediately upon recognition.

RESULTS

A total of 84 therapists (13 preceptors and 71 interns) participated in the treatments. The total number of treatments was 65,482. Ninety four (0.14%) adverse events were reported. There were fourteen categories: failure to remove needles (27 cases), ecchymosis or hematoma without pain (9 cases), ecchymosis or hematoma accompanied by pain (8 cases), burn injury (7 cases), discomfort (7 cases), dizziness (6 cases), nausea or vomiting (6 cases), pain in the punctured region (6 cases), minor hemorrhage (4 cases), aggravation of complaint (4 cases), malaise (3 cases), suspected contact dermatitis (3 cases), fever (3 cases) and numbness in the upper extremities (1 case).

CONCLUSION

No serious or severe cases such as pneumothorax, infection, or spinal cord injury were reported by the college preceptors and interns. The results indicate that serious or severe adverse events are rare in standard practice. We suggest that most severe or serious cases of adverse events caused by acupuncture reported in journals are actually cases of negligence. In the future, negligence should be discussed from the point of view of medical education and technical instruction for the therapists, and adverse reactions should be discussed from the point of view of incidence and prevention based on the result of further investigation.

Identification of a novel gene, OASIS, which encodes for a putative CREB/ATF family transcription factor in the long-term cultured astrocytes and gliotic tissue

Gliosis is a characteristic response of astrocytes to inflammation and trauma of the central nervous system (CNS). To study the mechanisms underlying gliosis, we performed differential display screening for genes specifically induced in long-term cultured astrocytes used as an in vitro gliosis model. We identified and characterized a gene (named OASIS, for old astrocyte specifically-induced substance) expressed in long-term cultured mouse astrocytes, or 'old astrocytes (OA)'. The OASIS gene encoded a putative transcription factor belonging to the cyclic AMP responsive element binding protein/activating transcription factor (CREB/ATF) gene family, with homology to box B-binding factor-2 (BBF-2), a Drosophila transcription factor. Its expression was developmentally regulated; OASIS mRNA was primarily expressed in the salivary gland and cartilage in the mouse embryo and it was transiently upregulated in the brain during postnatal two weeks. The expression became weaker in the adult brain. We also demonstrated that an expression of the OASIS mRNA was induced in response to the cryo-injury of the mouse cerebral cortex. The distribution pattern of the OASIS-positive cells in the injured cortex was very similar to that of the glial fibrillary acidic protein (GFAP)-positive cells. These results suggest that OASIS protein may play a role in gliotic events.

Eos: a novel member of the Ikaros gene family expressed predominantly in the developing nervous system

We identified a novel member of the Ikaros gene family, which has critical roles in the development of lymphoid lineages. This gene, which we named Eos, was expressed predominantly in the developing central and peripheral nervous system. Eos protein could interact with itself and Ikaros protein through its C-terminal portion in the yeast two hybrid assay. These findings suggested that Eos may have important roles in neural development similarly to the Ikaros family in the development of hemolymphoid tissue.