Trichinella spiralis-induced mastocytosis and erythropoiesis are simultaneously supported by a bipotent mast cell/erythrocyte precursor cell.

Anti-helminth responses require robust type 2 cytokine production that simultaneously promotes worm expulsion and initiates the resolution of helminth-induced wounds and hemorrhaging. However, how infection-induced changes in hematopoiesis contribute to these seemingly distinct processes remains unknown. Recent studies have suggested the existence of a hematopoietic progenitor with dual mast cell-erythrocyte potential. Nonetheless, whether and how these progenitors contribute to host protection during an active infection remains to be defined. Here, we employed single cell RNA-sequencing and identified that the metabolic enzyme, carbonic anhydrase (Car) 1 marks a predefined bone marrow-resident hematopoietic progenitor cell (HPC) population. Next, we generated a Car1-reporter mouse model and found that Car1-GFP positive progenitors represent bipotent mast cell/erythrocyte precursors. Finally, we show that Car1-expressing HPCs simultaneously support mast cell and erythrocyte responses during Trichinella spiralis infection. Collectively, these data suggest that mast cell/erythrocyte precursors are mobilized to promote type 2 cytokine responses and alleviate helminth-induced blood loss, developmentally linking these processes. Collectively, these studies reveal unappreciated hematopoietic events initiated by the host to combat helminth parasites and provide insight into the evolutionary pressure that may have shaped the developmental relationship between mast cells and erythrocytes.

Autoantibodies Against Carbonic Anhydrase I and II in Patients with Acute Myeloid Leukemia.

OBJECTIVE: Cancer, one of the principal causes of death, is a global social health problem. Autoantibodies developed against the organism's self-antigens are detected in the sera of subjects with cancer. In recent years carbonic anhydrase (CA) I and II autoantibodies have been shown in some autoimmune diseases and carcinomas, but the mechanisms underlying this immune response have not yet been explained. The aim of this study was to evaluate CA I and II autoantibodies in patients with acute myeloid leukemia (AML) and to provide a novel perspective regarding the autoimmune basis of the disease. MATERIALS AND METHODS: Anti-CA I and II antibody levels were investigated using ELISA in serum samples from 30 patients with AML and 30 healthy peers. RESULTS: Anti-CA I and II antibody titers in the AML group were significantly higher compared with the control group (p=0.0001 and 0.018, respectively). A strong positive correlation was also determined between titers of anti-CA I and II antibodies (r=0.613, p=0.0001). CONCLUSION: Our results suggest that these autoantibodies may be involved in the pathogenesis of AML. More extensive studies are now needed to reveal the entire mechanism.

Sera of patients with spontaneous tumour regression and elevated anti-CA I autoantibodies change the gene expression of ECM proteins.

Spontaneous tumour regression after high-dose therapy and autologous stem cell transplantation is associated with the aplastic anaemia-like syndrome and the presence of polyclonal autoantibodies against carbonic anhydrase I (CA I). When tumour cells were grown in vitro in the presence of patients' sera positive for anti-CA I autoantibodies, their morphological pattern was altered. These changes were accompanied by modifications in the gene expression profile. We observed downregulation of genes of the basal lamina assembly (collagen type IV alpha 4, the laminin subunit gamma 2), the extracellular matrix (collagen type I alpha 1), the cytoskeleton (keratin 14 type I), the collagen triple helix repeat containing 1 and the proto-oncogene WNT7B. On the other hand, the expression of the CA 1 gene was increased in the tumour cells. It was also noticed that the presence of anti-CA I autoantibodies did not impair tumour cell proliferation and cell viability in vitro. These findings were observed only in the presence of patients' sera positive for anti-CA I autoantibodies.

Carbonic Anhydrate I Epitope Peptide Improves Inflammation in a Murine Model of Inflammatory Bowel Disease.

BACKGROUND: Carbonic anhydrase I (CA I), a major cecal bacterial antigen, improves inflammatory bowel disease (IBD) symptoms in a murine model. The aim of this study was to identify the responsible epitope region within the CA I protein and evaluate its effect on inflammation using a murine IBD model. METHODS: Candidate peptides within the CA I protein sequence that interact with major histocompatibility complex class II were chosen and their immune responses were evaluated using mesentery lymph nodes (MLNs) from a CD4CD25 T-cell transfer murine colitis model. Mice were treated with regulatory dendritic cells (Reg-DCs)-pulsed CA I peptide. We assessed their clinical signs, histopathology, induction of cytokines and transcription factors, and generation of CD103CD11c dendritic cells and regulatory T cells (Tregs). RESULTS: We identified 4 candidate epitope peptides of CA I. Among these, Reg-DCs pulsed with CA I 58-73 peptide (Reg-DCsCA I 58-73) alone ameliorated colitis. Reg-DCsCA I 58-73-treated mice showed higher mRNA expression levels of forkhead box protein 3, aldehyde dehydrogenase family 1a2, transforming growth factor-ß, and interleukin (Il)10, when compared with lower mRNA expression of retinoic acid-related orphan receptor gamma and Il17a in MLNs. Compared with control mice, these mice also showed higher numbers of Foxp3CD4CD25 Tregs and CD103CD11c dendritic cells in MLNs and colon. Administration of Reg-DCsCA I 58-73 induced antigen-specific Tregs in MLNs of colitic mice. CONCLUSIONS: CA I 58-73 peptide induces antigen-specific therapeutic effect in a murine IBD model using Reg-DCs, indicating that CA I 58-73 is a candidate epitope for IBD immunotherapy.

Proteomic surveillance of putative new autoantigens in thyroid orbitopathy.

AIMS: Thyroid orbitopathy (TO) is an autoimmune inflammatory disorder characterised by several ocular manifestations. Several autoantigens have been proposed to be involved in the pathogenesis of TO, but the autoantigen system and the mechanism of TO would be rather complex. In this study, an immunoproteomic method was used to survey novel autoantigens expressed in the orbital fat tissue of patients with TO. METHODS: We used immunoproteomic, ELISA and immunohistochemical staining methods to survey novel autoantigens expressed in the orbital fat tissue of patients with TO. RESULTS: Six protein spots showing high reactivity with the serum from the patients with TO were detected as candidate orbital autoantigens, and two of them (carbonic anhydrase 1 (CA1) and alcohol dehydrogenase 1B (ADH1B)) were further verified by ELISA and immunohistochemical staining. We found that CA1 and ADH1B could attribute target autoantigens in this autoimmune disease. We discovered anti-CA1 and anti-ADH1B antibody prevalence to be higher in patients with TO (68.57%/51.43%) or Graves' disease (GD) (72%/48%) than in healthy controls respectively. Immunohistochemical staining study revealed the significantly enhanced expressions of CA1 and ADH1B in orbital fat of TO compared with that in healthy controls. CONCLUSIONS: We found that CA1 and ADH1B could attribute target autoantigens in this autoimmune disease. The high prevalence of these autoantibodies against CA1 and ADH1B in patients with TO and GD clarifies the potential clinical role for anti-CA1 and anti-ADH1B antibodies as biomarkers for GD and TO.

Overlap of epitopes recognized by anti-carbonic anhydrase I IgG in patients with malignancy-related aplastic anemia-like syndrome and in patients with aplastic anemia.

High titers of anti-carbonic anhydrase I (anti-CA I) autoantibodies were detected in the sera of patients with malignancies who developed an aplastic anemia-like (AA-like) syndrome after a high-dose therapy (HDT) and autologous stem cell transplantation (ASCT). It was found, that the presence of these anti-CA I autoantibodies is associated with spontaneous tumor regression. The main immunodominant epitopes of carbonic anhydrase isoform I (CA I) have previously been identified using epitope extraction technique in combination with mass spectrometric detection and bioinformatic verification. Similarly, the sera of patients with bona fide aplastic anemia (AA) who poorly responded to immunosuppressive treatment with anti-thymocyte globulin (ATG) demonstrated high titers of anti-CA I antibodies. In order to reveal differences between these antibodies, we applied the same methodology of epitope mapping procedure. Surprisingly, the anti-CA I antibodies from the both groups of patients compatibly recognized the same four candidate CA I epitopes--DGLAV, NVGHS, SLKPI, SSEQL. This finding may indicate common pathophysiological mechanisms in these two syndromes. However, at this moment it remains unresolved if anti-CA I antibodies are implicated in marrow or tumor suppression or are just an epi-phenomenon.

Autoantigenicity of carbonic anhydrase 1 in patients with abdominal aortic aneurysm, revealed by proteomic surveillance.

Abdominal aortic aneurysm (AAA) is sometimes detected in patients with atherosclerosis. One of the histological characteristics of AAA walls is infiltration of inflammatory cells, in which autoimmunity may be involved. Thereby, we here surveyed autoantigens in AAA walls by proteomics. Specifically, we separated proteins extracted from AAA wall samples by 2-dimensional electrophoresis and detected candidate autoantigens by western blotting. One of the detected candidates was carbonic anhydrase 1 (CA1). ELISA confirmed that the autoantibodies to CA1 were detected more frequently in AAA patients (n=13) than in healthy donors (n=25) (p=0.03). Interestingly, some serum samples from the AAA patients reacted to CA1 of the AAA walls stronger than to CA1 of peripheral blood mononuclear cells from healthy donors. Our data indicate that CA1 in the AAA walls would be modified to express neo-epitope(s) and that the autoimmunity to CA1 may be involved in the pathogenesis of AAA.

Oral administration of carbonic anhydrase I ameliorates murine experimental colitis induced by Foxp3-CD4+CD25- T cells.

IBDs are thought to involve uncontrolled innate and adaptive immunity against intestinal self-antigens and bacterial antigens. Mouse CA I is a major cecal bacterial antigen in fecal extracts and is implicated in the pathogenesis of IBD. We show here that oral tolerization to CA I induced antigen-specific protection from intestinal inflammation in a murine model. Oral administration of CA I but not irrelevant antigen (KLH) ameliorated CD4(+)CD25(-) T cell transfer murine colitis and DSS-induced murine colitis. Next, we investigated the mechanisms involved in the therapeutic effects of oral administration, such as induction of ALDH1a2, transcription factors, cytokines, CD103(+)CD11c(+) DCs, and generation of Tregs. Oral administration of CA I induced ALDH1a2 mRNA expression in the MLN and colon. When compared with PBS-treated mice, CA I-treated mice had higher Foxp3(+)CD4(+)CD25(+) Treg and CD103(+)CD11c(+) DC numbers in the MLN and colon; had higher TGF-ß production in the MLN and colon; had lower RORγt mRNA expression in the MLN and colon; and had lower IL-17 mRNA expression and production in the MLN. These results demonstrate that oral administration of CA I induced antigen-specific immune tolerance by generating Foxp3(+)CD4(+)CD25(+) Tregs and inhibiting Th17 cells in a murine colitis model, thus suggesting that oral tolerization with CA I is an effective therapeutic strategy for IBD regulation.

Carbonic anhydrase I is recognized by an SOD1 antibody upon biotinylation of human spinal cord extracts.

We recently reported the presence of a novel 32 kDa protein immunoreactive to a copper, zinc superoxide dismutase (SOD1) antibody within the spinal cord of patients with amyotrophic lateral sclerosis (ALS). This unique protein species was generated by biotinylation of spinal cord tissue extracts to detect conformational changes of SOD1 specific to ALS patients. To further characterize this protein, we enriched the protein by column chromatography and determined its protein identity by mass spectrometry. The protein that gave rise to the 32 kDa species upon biotinylation was identified as carbonic anhydrase I (CA I). Biotinylation of CA I from ALS spinal cord resulted in the generation of a novel epitope recognized by the SOD1 antibody. This epitope could also be generated by biotinylation of extracts from cultured cells expressing human CA I. Peptide competition assays identified the amino acid sequence in carbonic anhydrase I responsible for binding the SOD1 antibody. We conclude that chemical modifications used to identify pathogenic protein conformations can lead to the identification of unanticipated proteins that may participate in disease pathogenesis.

Identification of carbonic anhydrase I immunodominant epitopes recognized by specific autoantibodies which indicate an improved prognosis in patients with malignancy after autologous stem cell transplantation.

This work employs an epitope mapping of carbonic anhydrase (CA), isoform I (CA I), for detection of the main immunodominant epitopes. Our interest has arisen from an observed spontaneous tumor regression in patients who developed an aplastic anemia type syndrome after a high-dose therapy with autologous stem cell transplantation and whose sera contained high titer of anti carbonic anhydrase (anti-CA) autoantibodies. There are many indications that the presence of these autoantibodies may provide significant survival benefit for the patients. Western blot analysis confirmed strong immunoreactivity of the patients' sera with several CA isoforms and the CA I has been selected for our study as a highly abundant and widely distributed isoform. The applied analytical approach consists of specific fragmentation of CA I protein followed by immunospecific isolation of peptides reacting with polyclonal anti-CA I autoantibodies of patients in spontaneous remission. We improved the standard epitope mapping schema by incorporating the benefits of magnetic carriers and biomagnetic separation techniques. Mass spectrometry has been applied for detection and identification of epitopes and the acquired results were verified by bioinformatic tools. The candidate epitopes of CA I (NVGHS, DGLAV, SSEQL, and SLKPI) are discussed herein as potential therapeutic targets. This work highlights the usefulness of the epitope mapping technique based on magnetic microspheres for effective and rapid determination of immunodominant epitopes of the target protein.

Serum anti-carbonic anhydrase I and II antibodies and idiopathic recurrent pregnancy loss.

In up to 50% of recurrent pregnancy losses (RPL), the underlying pathophysiological mechanisms remain undetermined. Immunological factors may be involved. The objective of this study was to compare serum concentrations of autoantibodies to carbonic anhydrase (CA) I and II in women with and without RPL. Serum anti-CA-I and anti-CA-II concentrations in 29 women with RPL and 39 women without RPL on menstrual cycle day 3 were assessed and compared for this prospective age-matched controlled study. The mean serum anti-CA-I (0.287 +/- 0.177 versus 0.184 +/- 0.093, P = 0.003) and anti-CA-II (0.496 +/- 0.240 versus 0.344 +/- 0.108, P = 0.001) antibody concentrations were significantly higher in women with RPL, compared with controls. For serum anti-CA-I, an absorbance higher than 0.463 was taken as positive (mean + 3 SD of controls) and was detected in four of 29 patients with RPL (13.79%, 0.287 +/- 0.177). For serum anti-CA-II, an absorbance higher than 0.668 was taken as positive (mean + 3SD of controls) and was detected in seven of 29 patients with RPL (24.14%, 0.496 +/- 0.240). All patients with positive anti-CA-I antibody also had positive anti-CA-II antibody. Antibodies specifically reactive to CA-I and CA-II were found to be present at a higher frequency in the serum of subjects with RPL.

Increased serum anti-carbonic anhydrase II antibodies in patients with Graves' disease.

Carbonic anhydrase II (CA II) has an important role in thyroid hormone synthesis via regulating iodide (I-) transport across thyroidal cell membranes and the existence of autoantibodies against CA I and/or CA II have been shown in sera from patient with various autoimmune diseases such as Sjögren's Syndrome, Systemic Lupus Erythmatosus, type 1 diabetes, primary biliary cirrhosis and ulcerative colitis. The aim of this study was to investigate the presence of anti-CA I and CA II antibodies in autoimmune thyroid disease and the relationships between the autoantibodies and other clinical parameters. We studied 40 autoimmune thyroid patients (20 Hashimoto's thyroiditis, HT and 20 Graves' disease, GD ) and 21 healthy control subjects. Serum anti-CA I and CA II antibodies were screened by ELISA. Positive rate of anti-CA II (25%) antibody was significantly higher in GD patients as compared to HT patients and control subjects (p<0.05). There were no significant changes in positive rate of anti-CA I antibody. In addition, a significant correlation between serum anti-CA antibodies titers and other studied clinical parameters was not found. The results suggest that anti-CA II antibodies may be involved in the pathogenesis of GD.

Serological and proteomic evaluation of antibody responses in the identification of tumor antigens in renal cell carcinoma.

Renal cell carcinoma (RCC) is relatively resistant to conventional chemotherapy and radiotherapy. However, reports of spontaneous regression along with promising results in clinical trials suggest that immunotherapuetic strategies may be of clinical benefit. Few RCC related antigens have been identified to date, and the technical difficulty and time constraints of current antigen identification techniques preclude the screening of large numbers of patients. A comparatively rapid strategy has been used to identify components of tumors that elicit an antibody response in the patient - the serological and proteomic evaluation of antibody responses (SPEAR) approach. This combines two-dimensional polyarylamide gel electrophoresis of tumor and normal kidney samples with immunoblotting using autologous patient sera and protein identification by mass spectrometry. Using the SPEAR approach to screen RCC patients for naturally occurring antitumor antibody responses, a number of candidate immunogens have been identified in patients with high-grade disease and their relative expression levels in tumor tissue compared to normal tissue have been studied. These proteins include annexins I and IV, thymidine phosphorylase (TP), carbonic anhydrase I, Mn-superoxide dismutase and major vault protein (MVP). Downstream analysis of the tissue expression of some of these proteins shows that MVP is up-regulated in 2/4 of RCC tumors but is also expressed in normal kidney whereas TP is up-regulated in 100% (11/11) of RCC cases examined with no or minimal expression in normal kidney, indicating a potential use as a therapeutic target.

Low-avidity antibodies to carbonic anhydrase-I and -II in autoimmune chronic pancreatitis.

Antibodies (Abs) to carbonic anhydrase (isoforms CA-I and CA-II) have been considered pathogenic factors in the development of autoimmune pancreatitis. Besides, such autoAbs might accelerate the pancreatic damage in alcoholic chronic pancreatitis (CP). The aim of the present study was to evaluate the presence of serum Abs to CA-I and CA-II in CP and the relative affinity of these Abs. Serum anti-CA-I and -CA-II Abs were measured in 89 patients with CP (48 alcoholic and 41 nonalcoholic) by an ELISA technique. The prevalence of those autoAbs in CP was compared with other autoimmune diseases where they have also been found. The presence of other serological manifestations of autoimmunity, such as hypergammaglobulinemia or antinuclear Abs, was determined in CP patients as well. Elevated serum levels of both anti-CA-I (24%) and -CA-II (18%) Abs were observed in CP, although their prevalence was lower than in autoimmune diseases like rheumatoid arthritis (44 and 25%, respectively) or systemic lupus erythematosus (39% for anti-CA-I Abs). Furthermore, these Abs were of low average avidity. On the other hand, a significantly higher proportion of nonalcoholic CP had anti-CA-II Abs with respect to alcoholic CP (15.2 vs. 2.4%, p < 0.05). Anti-CA-I and -CA-II Abs might be helpful in the diagnosis of autoimmune CP, and the detection of the latter Abs seems to discard alcoholic etiology. Although it does not discard any pathogenic role in autoimmune CP, the low-avidity of anti-CA Abs argues against such idea.

Identification of tumor antigens in renal cell carcinoma by serological proteome analysis.

We have investigated the suitability of proteomics for identification of tumor-associated antigens. First, we compared the proteomes of nontumorous kidney and renal cell carcinoma (RCC) by two-dimensional gel electrophoresis (2-DE) and silver staining. Protein patterns were markedly different (approximately 800 spots in RCCs versus approximately 1400 spots in kidney). 2-DE immunoblotting revealed five RCC-specific spots, reproducibly reactive with RCC-patient but not healthy donor control sera. Two of these antigens were isolated by preparative 2-DE, and identified by Edman sequencing of tryptic peptides. The first antigen, smooth muscle protein 22-alpha (SM22-alpha), is an actin-binding protein of unknown function predominantly expressed in smooth muscle cells. In situ hybridization revealed that SM22-alpha is not expressed in the malignant cells but in mesenchymal cells of the tumor stroma. The second antigen represents carbonic anhydrase I (CAI), an isoform usually not expressed in kidney. Interestingly, a different isoform (CAXII) has previously been identified by serological expression cloning as an antigen overexpressed in some RCCs. In additional assays, antibodies to recombinant CAI or SM22-alpha were detected in sera from 3/11 or 5/11 RCC patients, respectively, whereas sera from 13 healthy individuals did not react. In conclusion, serological proteome analysis may be a new tool for the identification of tumor-associated antigens.