Differentially Expressed Genes in Dental Pulp Tissues of Individuals With Symptomatic Irreversible Pulpitis With and Without History of COVID-19.

INTRODUCTION: Increased levels of proinflammatory markers have been reported in tissues of individuals with Coronavirus Disease 2019 (COVID-19). We hypothesize that inflamed dental pulp tissues of individuals with previous history of COVID-19 may present a differential inflammatory gene expression profile in comparison with individuals who never had COVID-19. MATERIALS AND METHODS: Dental pulp tissues were collected from 27 individuals referred for endodontic treatment due to symptomatic irreversible pulpitis. Of these, 16 individuals had a history of COVID-19 (6 months to 1 year post infection) and 11 individuals had no previous history of COVID-19 (controls). Total RNA from pulp tissue samples was extracted and subjected to RNA sequencing for comparison of differentially expressed genes (DEGs) among groups. DEGs showing log2(fold change) > 1 or < -1, and P < .05 were considered significantly dysregulated. RESULTS: RNA sequencing identified 1461 genes as differentially expressed among the groups. Of these, 311 were protein coding genes, 252 (81%) that were upregulated and 59 (19%) that were downregulated in the COVID group compared with controls. The top upregulated genes in the COVID group were HSFX1 (4.12-fold change) and LINGO3 (2.06-fold change); significantly downregulated genes were LYZ (-1.52-fold change), CCL15 and IL8 (-1.45-fold change). CONCLUSIONS: Differential gene expression in dental pulp tissues of COVID and non-COVID groups suggests potential contribution of COVID-19 on dysregulating inflammatory gene expression in the inflamed dental pulp.

Dynamic Interactions Between the Immune System and the Neuroendocrine System in Health and Disease.

The immune system and the neuroendocrine system share many common features. Both consist of diverse components consisting of receptors and networks that are widely distributed throughout the body, and both sense and react to external stimuli which, on the one hand control mechanisms of immunity, and on the other hand control and regulate growth, development, and metabolism. It is thus not surprising, therefore, that the immune system and the neuroendocrine system communicate extensively. This article will focus on bi-directional immune-endocrine interactions with particular emphasis on the hormones of the hypothalamus-pituitary-thyroid (HPT) axis. New findings will be discussed demonstrating the direct process through which the immune system-derived thyroid stimulating hormone (TSH) controls thyroid hormone synthesis and bone metamorphosis, particularly in the context of a novel splice variant of TSHß made by peripheral blood leukocytes (PBL). Also presented are the ways whereby the TSHß splice variant may be a contributing factor in the development and/or perpetuation of autoimmune thyroid disease (AIT), and how systemic infection may elicit immune-endocrine responses. The relationship between non-HPT hormones, in particular adipose hormones, and immunity is discussed.

Thyroid stimulating hormone ß-subunit splice variant is expressed in all fractional subsets of bone marrow hematopoietic cells and peripheral blood leukocytes and is modulated during bacterial infection.

Thyroid stimulating hormone (TSH), a hormone produced in the anterior pituitary, is used to regulate thyroid hormone secretion. It has been known for over three decades that TSH is made by the cells of the immune system; however, the functional role of immune system TSH is unclear. We previously demonstrated that an alternatively-spliced isoform of TSHß, referred to as the TSHß splice variant (TSHßv), is the primary form of TSHß made by hematopoietic cells in mice and humans. Most studies have linked TSHßv expression to myeloid cells of the immune system; however, it has recently been demonstrated that plasma cells in patients with Hashimoto's thyroiditis may be a source of immune system TSHßv. Here, we demonstrate that TSHßv is expressed in bone marrow precursors of lymphoid cells, monocytes, and granulocytes, as well as in mesenteric lymph node (MLN) cells. Plasma cells generated by in vitro culture with bacterial lipopolysaccharide (LPS), and MLN cells from mice infected with L. monocytogenes expressed TSHßv. There was an increase in the intensity of intracellular TSHßv expression in MLN cells following exposure to LPS, and in the proportion of TSHßv+ CD138+ MLN cells following L. monocytogenes infection. The number of TSHßv+ cells increased in MLN cells, particularly among CD138+ cells, following bacterial infection. This was confirmed by an increase in gene expression of BLIMP-1, the transcription factor for CD138, following infection. Levels of circulating thyroxine dropped significantly in mice 24 hrs post-infection. These findings suggest that immune system TSHßv may contribute to the host immune response during bacterial infection.

Novel Splicing of Immune System Thyroid Stimulating Hormone ß-Subunit-Genetic Regulation and Biological Importance.

Thyroid stimulating hormone (TSH), a glycoprotein hormone produced by the anterior pituitary, controls the production of thyroxine (T4) and triiodothyronine (T3) in the thyroid. TSH is also known to be produced by the cells of the immune system; however, the physiological importance of that to the organism is unclear. We identified an alternatively-spliced form of TSHß that is present in both humans and mice. The TSHß splice variant (TSHßv), although produced at low levels by the pituitary, is the primary form made by hematopoietic cells in the bone marrow, and by peripheral leukocytes. Recent studies have linked TSHßv functionally to a number of health-related conditions, including enhanced host responses to infection and protection against osteoporosis. However, TSHßv also has been associated with autoimmune thyroiditis in humans. Yet to be identified is the process by which the TSHßv isoform is produced. Here, a set of genetic steps is laid out through which human TSHßv is generated using splicing events that result in a novel transcript in which exon 2 is deleted, exon 3 is retained, and the 3' end of intron 2 codes for a signal peptide of the TSHßv polypeptide.

Involvement of Ly6C, 4-1BB, and KLRG1 in the activation of lamina propria lymphocytes in the small intestine of sanroque mice.

Roquin is an E3 ligase that regulates mRNA stability. Mice with a mutation in the Rc3h1 gene and Roquin protein, referred to as Roquinsan/san or sanroque mice, develop broad-spectrum chronic inflammatory conditions and autoimmune pathologies. Our laboratory recently reported that sanroque mice also develop extensive inflammation that is localized in the small intestine but is rare in the colon. Here, we demonstrate that small intestinal intraepithelial lymphocytes (IELs) are present in the epithelium of sanroque mice but that cell recoverability is low using standard extraction techniques even though lamina propria lymphocytes (LPLs) can be recovered in normal numbers. In studies aimed at characterizing T cell costimulatory markers and activation molecules on LPLs in sanroque mice, we identified Ly6C and 4-1BB (CD137) as being expressed at elevated levels on sanroque small intestinal LPLs, and we show that both of those subsets, in conjunction with cells expressing the KLRG1 T cell activation molecule, are sources of IL-17A, IFN-γ, and TNFα. TNFα was primarily produced by 4-1BB+, KLRG1-cells, but was also made by some 4-1BB-, KLRG1-cells, and 4-1BB-, KLRG1+ cells. These findings collectively suggest that the small intestinal inflammatory response in sanroque mice is driven, at least in part, by LPL activation through Ly6C and 4-1BB signaling, and they provide further evidence in support of using the sanroque mouse as an animal model of chronic small intestinal inflammation.

Splenic Leukocytes Traffic to the Thyroid and Produce a Novel TSHß Isoform during Acute Listeria monocytogenes Infection in Mice.

The thyroid stimulating hormone beta-subunit (TSHß) with TSHα form a glycoprotein hormone that is produced by the anterior pituitary in the hypothalamus-pituitary-thyroid (HPT) axis. Although TSHß has been known for many years to be made by cells of the immune system, the role of immune system TSH has remained unclear. Recent studies demonstrated that cells of the immune system produce a novel splice variant isoform of TSHß (TSHßv), but little if any native TSHß. Here, we show that within three days of systemic infection of mice with Listeria monocytogenes, splenic leukocytes synthesized elevated levels of TSHßv. This was accompanied by an influx of CD14+, Ly6C+, Ly6G+ cells into the thyroid of infected mice, and increased levels of intrathyroidal TSHßv gene expression. Adoptive transfer of carboxyfluorescein succinimidyl ester (CFSE)-labeled splenic leukocytes from infected mice into non-infected mice migrated into the thyroid as early as forty-eight hours post-cell transfer, whereas CFSE-labeled cells from non-infected mice failed to traffic to the thyroid. These findings demonstrate for the first time that during bacterial infection peripheral leukocytes produce elevated levels of TSHßv, and that spleen cells traffic to the thyroid where they produce TSHßv intrathyroidally.

MicroRNA signatures differentiate Crohn's disease from ulcerative colitis.

BACKGROUND: Excessive and inappropriate immune responses are the hallmark of several autoimmune disorders, including the inflammatory bowel diseases (IBD): Crohn's disease (CD) and ulcerative colitis (UC). A complex etiology involving both environmental and genetic factors influences IBD pathogenesis. The role of microRNAs (miRNAs), noncoding RNAs involved in regulating numerous biological processes, to IBD pathology, in terms of initiation and progression, remains ill-defined. In the present study, we evaluated the relationship between colon, peripheral blood, and saliva whole miRNome expression in IBD patients and non-inflammatory bowel disease (non-IBD) controls to identify miRNAs that could discriminate CD from UC. Quantitative real-time PCR (qRT-PCR) was used to validate and assess miRNA expression. RESULTS: Microarray analysis demonstrated that upwards of twenty six miRNAs were changed in CD and UC colon biopsies relative to the non-IBD controls. CD was associated with the differential expression of 10 miRNAs while UC was associated with 6 miRNAs in matched colon tissues. CD was associated with altered expression of 6 miRNAs while UC was associated with 9 miRNAs in whole blood. Expression of miR-101 in CD patients and miR-21, miR-31, miR-142-3p, and miR-142-5p in UC patients were altered in saliva. CONCLUSIONS: Our results suggest that there is specific miRNA expression patterns associated with UC versus CD in three separate tissue/body fluids (colon, blood, and saliva). Further, the aberrant miRNA expression profiles indicate that miRNAs may be contributory to IBD pathogenesis, or at least reflect the underlying inflammation. Scrutinizing miRNA expression in saliva and blood samples may be beneficial in monitoring or diagnosing disease in IBD patients. A panel of miRNAs (miR-19a, miR-21, miR-31, miR-101, miR-146a, and miR-375) may be used as markers to identify and discriminate between CD and UC.

A role for IL-10 in the transcriptional regulation of Roquin-1.

Roquin-1, a RING finger E3 ubiquitin ligase, functions as a modulator of inflammation; however, nothing is known about how Rc3h1 expression is regulated. Here, we describe an opposing relationship between Roquin-1 and the IL-17 proinflammatory cytokine by demonstrating that enforced expression of Rc3h1 restricts Il17a expression, and that exposure of T cells to IL-10, a cytokine with immunosuppressive activity, increases Rc3h1 expression. Luciferase reporter assays conducted using eight transcription factor plasmids (STAT1, STAT3, STAT5, GATA2, c-Rel, IKZF1, IKZF2, and IKZF3) demonstrated that STAT1, STAT3, GATA2, and c-Rel increased Rc3h1 promoter activity, whereas IKZF2 decreased activity. Gene expression of those five transcription factors increased in T cells exposed to IL-10. Transcription factor-specific siRNAs suppressed the IL-10 effect on Rc3h1 transcription. These findings identify a role for IL-10 in regulating Rc3h1 transcription, and they have implications for understanding how Roquin-1 controls the immune response.

Hematopoietic not systemic impairment of Roquin expression accounts for intestinal inflammation in Roquin-deficient mice.

Roquin, an E3 ligase, is involved in curtailing autoimmune pathology as seen from studies using mice with mutated (Rc3h1(san/san)) or disrupted (Rc3h1(gt/gt)) Rc3h1 gene. The extent to which intestinal immunopathology is caused by insufficient Roquin expression in the immune system, or by Roquin impairment in non-hematopoietic cells, has not been determined. Using bone marrow cells from Rc3h1(gt/gt) mice transferred into irradiated normal mice (Rc3h1(gt/gt) → NL chimeras), we show that inflammation developed in the small intestine, kidney, lung, liver, and spleen. Proinflammatory cytokine levels were elevated in lamina propria lymphocytes (LPLs). Inflammation in the liver was accompanied by areas of hepatocyte apoptosis. Lung inflammation consisted of an influx of both T cells and B cells. Small intestinal LPLs had increased numbers of CD44(hi), CD62L(lo), KLRG1(+), ICOS(+) short-lived effector cells, indicating an influx of activated T cells. Following oral infection with L. monocytogenes, Rc3h1(gt/gt) → NL chimeras had more liver pathology and greater numbers of bacteria in the Peyer's patches than NL → NL chimeras. These findings demonstrate that small intestinal inflammation in Rc3h1(san/san) and Rc3h1(gt/gt) mice is due to a failure of Roquin expression in the immune system and not to insufficient systemic Roquin expression.

Biological Impact of the TSHß Splice Variant in Health and Disease.

Thyroid stimulating hormone (TSH), a glycoprotein hormone composed of α and ß chains, is produced by thyrotrope cells of the anterior pituitary. Within the conventional endocrine loop, pituitary-derived TSH binds to receptors in the thyroid, resulting in the release of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). T4 and T3 in turn regulate nearly every aspect of mammalian physiology, including basal metabolism, growth and development, and mood and cognition. Although TSHß has been known for years to be produced by cells of the immune system, the significance of that has remained largely unclear. Recently, a splice variant of TSHß (TSHßv), which consists of a truncated but biologically functional portion of the native form of TSHß, was shown to be produced by bone marrow cells and peripheral blood leukocytes, particularly cells of the myeloid/monocyte lineage. In contrast, full-length native TSHß is minimally produced by cells of the immune system. The present article will describe the discovery of the TSHßv and will discuss its potential role in immunity and autoimmunity, inflammation, and bone remodeling.

Small intestine inflammation in Roquin-mutant and Roquin-deficient mice.

Roquin, an E3 ubiquitin ligase that localizes to cytosolic RNA granules, is involved in regulating mRNA stability and translation. Mice that have a M199R mutation in the Roquin protein (referred to as sanroque or Roquin(san/san) mice) develop autoimmune pathologies, although the extent to which these occur in the intestinal mucosa has not been determined. Here, we demonstrate that Roquin(san/san) mice reproducibly develop intestinal inflammation in the small intestine but not the colon. Similarly, mice generated in our laboratory in which the Roquin gene was disrupted by insertion of a gene trap cassette (Roquin(gt/gt) mice) had small intestinal inflammation that mimicked that of Roquin(san/san) mice. MLN cells in Roquin(san/san) mice consisted of activated proliferating T cells, and had increased numbers of CD44(hi) CD62L(lo) KLRG1(+) short-lived effector cells. Proportionally more small intestinal intraepithelial lymphocytes in Roquin(san/san) mice expressed the ICOS T cell activation marker. Of particular interest, small intestinal lamina propria lymphocytes in Roquin(san/san) mice consisted of a high proportion of Gr-1(+) T cells that included IL-17A(+) cells and CD8(+) IFN-γ(+) cells. Extensive cytokine dysregulation resulting in both over-expression and under-expression of chemotactic cytokines occurred in the ileum of Roquin(san/san) mice, the region most prone to the development of inflammation. These findings demonstrate that chronic inflammation ensues in the intestine following Roquin alteration either as a consequence of protein mutation or gene disruption, and they have implications for understanding how small intestinal inflammation is perpetuated in Crohn's disease (CD). Due to the paucity of animal models of CD-like pathophysiology in the small intestine, and because the primary gene/protein defects of the Roquin animal systems used here are well-defined, it will be possible to further elucidate the underlying genetic and molecular mechanisms that drive the disease process.

Quantization and fractional quantization of currents in periodically driven stochastic systems. I. Average currents.

This article studies Markovian stochastic motion of a particle on a graph with finite number of nodes and periodically time-dependent transition rates that satisfy the detailed balance condition at any time. We show that under general conditions, the currents in the system on average become quantized or fractionally quantized for adiabatic driving at sufficiently low temperature. We develop the quantitative theory of this quantization and interpret it in terms of topological invariants. By implementing the celebrated Kirchhoff theorem we derive a general and explicit formula for the average generated current that plays a role of an efficient tool for treating the current quantization effects.

Quantization and fractional quantization of currents in periodically driven stochastic systems. II. Full counting statistics.

We study Markovian stochastic motion on a graph with finite number of nodes and adiabatically periodically driven transition rates. We show that, under general conditions, the quantized currents that appear at low temperatures are a manifestation of topological invariants in the counting statistics of currents. This observation provides an approach for classification of topological properties of the counting statistics, as well as for extensions of the phenomenon of the robust quantization of currents at low temperatures to the properties of the counting statistics which persist to finite temperatures.

A defect in the synthesis of Interferon-γ by the T cells of Complement-C5 deficient mice leads to enhanced susceptibility for tuberculosis.

Interferon-γ (IFNγ) plays a major role during host defense against Mycobacterium tuberculosis (Mtb). T cells produce IFNγ in response to IL-12 and IL-18 secreted from Mtb infected macrophages. IFNγ in turn, induces nitric oxide secretion in macrophages that kills Mtb. IFNγ knockout mice are thus hyper-susceptible to tuberculosis. We reported earlier that Complement-C5 deficient (C5(-/-)) congenic mice are more susceptible to tuberculosis and showed reduced IL-12 synthesis in their macrophages. Using C5(-/-) congenic mice that carry a deletion in the C5 gene and the wild type C5(+/+) mice, we demonstrate here that, the C5(-/-) derived CD3(+) T cells, have an additional defect in the synthesis of IFNγ. C5(-/-) T cells produced lower levels of IFNγ upon stimulation by antigen presenting cells (APCs) infected with Mtb or when stimulated directly with a combination of IL-12 and IL-18. The latter was in part due to a reduced phosphorylation of STAT4 following IL-12/IL-18 stimulation. Addition of C5a peptide to IL-12/IL-18 partially restored STAT4 phosphorylation and IFNγ synthesis in C5(-/-) T cells indicating that IL-12/IL-18 mediated signaling within CD3(+) T cells involves C5a peptide. Finally, C5(-/-) T cells derived from M. bovis BCG or Mtb infected mice showed a reduced expression of T-bet (T-box expressed in T cells) transcription factor, which correlated well with a reduced T cell secretion of IFNγ. Since T-bet mediated IFNγ synthesis facilitates Th1 expansion, C5(-/-) mouse derived T cells appear to have an intrinsic defect in the production of IFNγ, which is related to C5 deficiency and this may explain their increased susceptibility to infection with Mtb and BCG.

Selective upregulation of microRNA expression in peripheral blood leukocytes in IL-10-/- mice precedes expression in the colon.

IL-10(-/-) mice, an animal model of Th1-mediated inflammatory bowel disease, were screened for the expression of 600 microRNAs (miRNAs) using colonic tissues and PBLs from animals having either mild inflammation or severe intestinal inflammation. The development of colonic inflammation in IL-10(-/-) mice was accompanied by upregulation in the expression of 10 miRNAs (miR-19a, miR-21, miR-31, miR-101, miR-223, miR-326, miR-142-3p, miR-142-5p, miR-146a, and miR-155). Notably, the expression of all of these miRNAs plus miR-375 was elevated in PBLs of IL-10(-/-) mice at a time when colonic inflammation was minimal, suggesting that changes in specific miRNAs in circulating leukocytes may be harbingers of ensuing colonic pathology. In vitro exposure of colonic intraepithelial lymphocytes to IL-10 resulted in downregulation of miR-19a, miR-21, miR-31, miR-101, miR-223, and miR-155. Interestingly, unlike IL-10(-/-) mice, changes in miRNAs in PBL of dextran sulfate sodium-treated mice were minimal but selectively elevated in the colon after pathology was severe. We further show that miR-223 is a negative regulator of the Roquin ubiquitin ligase, Roquin curtails IL-17A synthesis, and the 3' untranslated region of Roquin is a target for miR-223, thus defining a molecular pathway by which IL-10 modulates IL-17-mediated inflammation. To identify additional miRNAs that may be involved in the regulation of Roquin, transcriptome analysis was done using cDNAs from HeLa cells transfected with 90 miRNA mimics. Twenty-six miRNAs were identified as potential negative regulators of Roquin, thus demonstrating functional complexity in gene expression regulation by miRNAs.

Immunological regulation of metabolism--a novel quintessential role for the immune system in health and disease.

The hypothalamus-pituitary-thyroid (HPT) axis is an integrated hormone network that is essential for maintaining metabolic homeostasis. It has long been known that thyroid stimulating hormone (TSH), a central component of the HPT axis, can be made by cells of the immune system; however, the role of immune system TSH remains enigmatic and most studies have viewed it as a cytokine used to regulate immune function. Recent studies now indicate that immune system-derived TSH, in particular, a splice variant of TSHß that is preferentially made by cells of the immune system, is produced by a subset of hematopoietic cells that traffic to the thyroid. On the basis of these and other findings, we propose the novel hypothesis that the immune system is an active participant in the regulation of basal metabolism. We further speculate that this process plays a critical role during acute and chronic infections and that it contributes to a wide range of chronic inflammatory conditions with links to thyroid dysregulation. This hypothesis, which is amenable to empirical analysis, defines a previously unknown role for the immune system in health and disease, and it provides a dynamic connection between immune-endocrine interactions at the organismic level.

Differential cytokine patterns in mouse macrophages and gingival fibroblasts after stimulation with porphyromonas gingivalis or Escherichia coli lipopolysaccharide.

BACKGROUND: A major cause of chronic inflammatory periodontal disease is Porphyromonas gingivalis, a non-motile, Gram-negative, rod-shaped, anaerobic bacterium. Within gingival tissue, both macrophages and fibroblasts participate in the immune response to foreign entities by releasing cytokines and expressing molecules to recruit and activate lymphocytes. However, the contribution of gingival macrophages and fibroblasts to the immune response to P. gingivalis infection is not fully known. METHODS: The AMJ2-C8 cell line (AM cells), a mouse alveolar macrophage cell line, and ESK-1 cells, a mouse gingival fibroblast cell line made in our laboratory, were treated with lipopolysaccharide (LPS) from either P. gingivalis or Escherichia coli. The expression of immune response molecules was quantified by real-time polymerase chain reaction and enzyme-linked immunoassay. RESULTS: AM and ESK-1 cells responded differently to P. gingivalis and E. coli LPS stimulation. The ESK-1 gingival fibroblast cell line was more responsive to E. coli LPS stimulation as seen by elevated levels of interleukin (IL)-6, inducible nitric oxide, and monocyte chemotactic protein-1 expression relative to stimulation by P. gingivalis LPS. Conversely, the AM macrophage cell line was more responsive to P. gingivalis LPS stimulation, particularly for interleukin IL-1ß, IL-6, and monocyte chemotactic protein-1, relative to stimulation by E. coli LPS. CONCLUSION: These findings demonstrate that E. coli LPS induces a stronger cytokine and chemokine response in gingival fibroblasts, whereas P. gingivalis LPS induces a stronger response in macrophages.

Soluble gp130 promotes intestinal epithelial hyperplasia during reovirus infection.

Soluble gp130 (sgp130) has been shown to suppress the inflammatory response of autoimmune pathologies; however, its effects on virus infection are not known. Here, we report that intraperitoneal treatment of mice with sgp130-Fc fusion protein at the time of oral reovirus serotype 3 infection resulted in altered morphopathological changes that were evident by less shortening of intestinal villi length and crypt depth after infection. That the effect mediated by sgp130 treatment was due to an increase in intestinal crypt cell proliferation was demonstrated by an increase in the number of crypt mitotic figures. This was further confirmed by increased immunoreactivity to the Cdc47 proliferation-associated antigen in crypts of sgp130-treated virus-infected mice compared to infected non-treated mice. These findings suggest that sgp130 may have a beneficial effect during intestinal virus infection by disrupting interleukin-6 trans-signalling, thereby reducing the local inflammatory response.

ICOS promotes IL-17 synthesis in colonic intraepithelial lymphocytes in IL-10-/- mice.

In the absence of IL-10, colonic inflammation ensues, which is characterized by high levels of IL-17. Here, we demonstrate a direct correlation between ICOS expression and IL-17 production in cIELs. IL-10(-/-) mice had increased numbers of cIELs and greater colon weight. Although the CD69 early activation antigen was expressed on cIELs from normal and IL-10(-/-) mice, ICOS was expressed only on cIELs from IL-10(-/-) mice. IL-17-producing cells in IL-10(-/-) mice consisted of CD4(+) and CD8(+) cIELs; however, CD4(+) cells were the predominant IL-17-producing cell population. Culture of cIELs from IL-10(-/-) mice with IL-23 resulted in an increase in ICOS and IL-17 expression, whereas IL-10 suppressed expression of ICOS and IL-17. This occurred in primary cultures and recall stimulation experiments. The ICOS ligand B7RP-1 was up-regulated on colonic epithelial cells and on a population of large granular leukocytes during inflammation. Culture of cIELs with B7RP-1(+) DCs enhanced IL-17A production from normal cIELs but failed to do so using cIELs from ICOS(-/-) mice. In vivo treatment of IL-10(-/-) mice with antibody to ICOS resulted in a significant reduction in colonic pathology. These findings implicate ICOS as an activational signal of Th17 cells during chronic intestinal inflammation, and they suggest that under some conditions, control of ICOS expression may help to suppress chronic intestinal inflammation.

A novel thyroid stimulating hormone beta-subunit isoform in human pituitary, peripheral blood leukocytes, and thyroid.

Thyroid stimulating hormone (TSH) is produced by the anterior pituitary and is used to regulate thyroid hormone output, which in turn controls metabolic activity. Currently, the pituitary is believed to be the only source of TSH used by the thyroid. Recent studies in mice from our laboratory have identified a TSHbeta isoform that is expressed in the pituitary, in peripheral blood leukocytes (PBL), and in the thyroid. To determine whether a human TSHbeta splice variant exists that is analogous to the mouse TSHbeta splice variant, and whether the pattern of expression of the splice variant is similar to that observed in mice, PCR amplification of RNAs from pituitary, thyroid, PBL, and bone marrow was done by reverse-transcriptase PCR and quantitative realtime PCR. Human pituitary expressed a TSHbeta isoform that is analogous to the mouse TSHbeta splice variant, consisting of a 27 nucleotide portion of intron 2 and all of exon 3, coding for 71.2% of the native human TSHbeta polypeptide. Of particular interest, the TSHbeta splice variant was expressed at significantly higher levels than the native form or TSHbeta in PBL and the thyroid. The TSHalpha gene also was expressed in the pituitary, thyroid, and PBL, but not the BM, suggesting that the TSHbeta polypeptide in the thyroid and PBL may exist as a dimer with TSHalpha. These findings identify an unknown splice variant of human TSHbeta. They also have implications for immune-endocrine interactions in the thyroid and for understanding autoimmune thyroid disease from a new perspective.