Interleukin 17-Producing γδ T Cells Increased in Patients with Active Pulmonary Tuberculosis

Although it has been known that γδ T cells may play an important role in the immune response to infection of Mycobacterium tuberculosis （M. tb）, the mechanisms by which the γδ T cells participate in the innate and/or acquired immunity to tuberculosis （TB） have not been full elucidated. In the present study, 27 patients with active pulmonary TB and 16 healthy donors （HD） were performed. We found that proportion of IL-17-producing cells among lymphocyte was similar between TB patients and HD, whereas the proportions of γδ T cells in IL-17-producing cells （59.2%） and IL-17-producing cells in γδ T cells （19.4%） in peripheral blood were markedly increased in TB patients when compared to those in HD （43.9% and 7.7%, respectively）. In addition, the proportions of IFN-T-producing γδ T cells in TB patients were obviously lower than that in HD. Upon re-stimulated with M. tb heat-treated antigen （M. tb-HAg） in vitro, fewer IL-17-producing γδ T cells were generated from HD and TB patients, whereas IFN-T-producing γδ T cells were increased in TB patients compared to that in HD. Our findings in TB patients and healthy human were consistent with other murine investigation that the IL-17- producing γδ T cells were main source of IL-17 in mouse model of BCG infection, suggesting that γδ T cells might be involved in the formation of tubercular granuloma in pulmonary TB patients, but need further identification.     

Antigen-Driven Clonal Accumulation of Peritoneal γδ T Cells in vivo

How the clonality of γδ T cells changes in response to exogenous antigens is uncertain. Here we analyzed kinetics of Vγ1.1 and Vγ2 T cell clonality after intraperitoneal injection of purified protein derivatives (PPD) by the heterogeneity of the third complementarity determining region (CDR3) length in Vγ1.1-Jγ4-Cγ4 and Vγ2-Jγ1-Cγ1 junctions. The V-J junctions were analyzed in intrahepatic lymphocytes (IHL), spleen cells, and peritoneal exudate cells (PEC) by polyacrylamide gel electrophoresis. γδ T cells expressing Vγ1.1 and Vγ2 genes were heterogeneous in normal mice. Accumulation of specific Vγ1.1 T cell clones was transiently detected 7 days after the injection in PEC, but no accumulation was observed in IHL and spleen cells. The accumulated clones disappeared by 4 weeks. Transient accumulation of Vγ2 T cell clones was also observed in PEC at the early phase after the injection. These results suggest that γδ T cells with specific TCR respond to PPD and temporary accumulate in the peritoneal cavity, but not in liver and spleen.     

Cerebellar Liponeurocytoma,an Unusual Tumor of the Central Nervous System – Ultrastructural Examination

Cerebellar liponeurocytoma is a rare tumor of the central nervous system which shows neuronal and variable astrocytic differentiation, along with foci of lipomatous differentiation. It is usually located in the cerebellum, and may be mistaken for medulloblastoma with lipidized cells or lipomatous ependymoma. Histopathological examination, supplemented by immunohistochemistry and electron microscopy, is required to distinguish between these entities. This 35-year-old male presented with vomiting and headache for three months, followed by gait imbalance. Neurological examination showed positive cerebellar signs with ataxic gait. Magnetic resonance imaging showed a lesion measuring 4.4?cm×?4.3?cm×?3.9?cm involving the cerebellum. The patient underwent midline suboccipital craniotomy to excise the tumor. Histopathological examination showed a circumscribed, cellular tumor composed of round to polygonal cells with moderate cytoplasm and minimal pleomorphism. Clear intracytoplasmic vacuoles were seen within the tumor cells. These tumor cells were immunopositive for synaptophysin, NSE, and MAP-2, confirming their neurocytic origin. On ultrastructural examination, lipid vacuoles as well as dense-core neurosecretory granules were identified within these neurocytic cells, confirming the diagnosis of liponeurocytoma. No cilia, microvilli, or gap junctions were identified in the tumor cells, ruling out the possibility of lipomatous ependymoma. The differentiation of liponeurocytoma from its morphological mimics is imperative, as their treatment differs drastically. The role of electron microscopy is extremely important in this differential diagnosis.     

Change in Resonance Properties of the Central Nervous System in 6–11 Year-Old Children

Basic and reactive characteristics of EEG in children of 6–11 years were studied under conditions rhythmic photostimulation. We showed that the efficiency of photostimulated entrainment reaction determines functional maturity of the corresponding brain oscillators. __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 140, No. 10, pp. 377–380, October, 2005     

Levels of Circulating Th17 Cells and Regulatory T Cells in Ankylosing Spondylitis Patients with an Inadequate Response to Anti−TNF-α Therapy

Purpose

To investigate the effects of TNF-α blockage on levels of circulating Th17, Treg and their related cytokines in ankylosing spondylitis (AS) patients with different response to anti-TNF-α therapy.

Methods

The frequencies of circulating Th17 and Treg and serum levels of related cytokines were determined using flow cytometry analysis and ELISA, respectively, in 222 AS patients both before (baseline) and 6 months after anti-TNF-α therapy. Therapeutic response was defined according to ASAS (Assessment in Spondyloarthritis International Society) response criteria.

Results

Significantly higher baseline circulating Th17 and serum TNF-α, IL-6, IL-17, IL-23 were observed in active AS patients than in healthy controls. After anti-TNF-α therapy, 168 patients (75.7 %) were responders and 54 (24.3 %) were non-responders. Frequencies of Th17 significantly decreased in responders, but significantly increased in non-responders. Treg increased significantly in responders but decreased significantly in non-responders. Levels of TNF-α, IL-6, IL-17, and IL-23 were significantly decreased in responders. In contrast, IL-17 and IL-23 significantly increased in non-responders. TGF-β were significantly increased only in responders, whereas no significant changes were seen in IL-10 in either responders or non-responders. Spearman correlation analysis showed that frequencies of Th17 and levels of TNF-α, IL-6, IL-17, and IL-23 were positively correlated with BASDAI score. They were also positively correlated with BASFI score except for IL-6. Treg were found to be negatively correlated with BASDAI score.

Conclusions

The beneficial effect of anti-TNF-α therapy in AS might not only neutralize the effects of TNF-α but also down-regulate Th17 and Th17-related cytokines accompanied by up-regulating the Treg/TGF-β axis in responders.     

Vγ9-Vδ2+ γδ T Cells from a Patient with Felty Syndrome That Exhibit Aberrant Response to Triggering of the CD3 Molecule Can Regulate Immunoglobulin Secretion by B Cells

Expanded populations of T lymphocytes bearing γδ T cell receptors have been detected in several patients with Felty syndrome. The goal of this study was to functionally characterize these lymphocytes in a newly described patient with this disease. For this, fluorescence-activated cell sorter analysis of T cell surface antigens, proliferation, and tumor necrosis factor α enzyme-linked immunosorbent assays, as well as quantitative assays of immunoglobulins secreted by pokeweed mitogen-driven B cells were performed. The γδ cells, that expressed a CD3⁺CD4^-Vγ9^-Vδ2⁺Cδ⁺ phenotype, and constituted 60% of the peripheral blood T cells, did not proliferate after triggering with anti-CD3, but did secrete tumor necrosis factor α and the addition of these cells to pokeweed mitogen-stimulated B cells from the patient decreased their secretion of immunoglobulin M while augmenting IgG secretion. These data suggest that the expanded anergic Vγ9^-Vδ2⁺ γδ cells can play an immunoregulatory role in the patient.     

Olfactory Ensheathing Glia: Drivers of Axonal Regeneration in the Central Nervous System?

Olfactory ensheathing glia (OEG) accompany olfactory growing axonsin their entry to the adult mammalian central nervous system (CNS).Due to this special characteristic, considerable attention has beenfocused on the possibility of using OEG for CNS regeneration. OEGpresent a large heterogeneity in culture with respect to theircellular morphology and expressed molecules. The specificcharacteristics of OEG responsible for their regenerativeproperties have to be defined. These properties probably resultfrom the combination of several factors: molecular composition ofthe membrane (expressing adhesion molecules as PSA-NCAM, L1 and/orothers) combined with their ability to reduce glial scarring and toaccompany new growing axons into the host CNS. Their capacity toproduce some neurotrophic factors might also account for theirability to produce CNS regeneration.     

A Novel Mutation in a Patient with Hyperparathyroidism–Jaw Tumour Syndrome

Hyperparathyroidism–jaw tumour syndrome (HPT-JT) is a rare variant of familial hyperparathyroidism, characterized by primary hyperparathyroidism (PHPT) due to one or multiple parathyroid adenomas, and benign tumours of the mandible and maxilla. It has an autosomal dominant pattern of inheritance, and is associated with mutations that deactivate the cell division cycle protein 73 homolog (CDC73) gene, also known as hyperparathyroidism 2 (HRPT2), located on the long arm of chromosome 1, that encodes for the tumour suppressor protein parafibromin. In the majority of cases, PHPT is the presenting symptom, but up to 30 % of HPT-JT cases initially present with an ossifying fibroma of the maxillofacial bones. HPT-JT may result in severe hypercalcemia-related complications and an elevated risk of parathyroid carcinoma. For this reason, early identification of the disease is important. We present the case of a 23-year-old woman who was found to have jaw tumours and was later diagnosed with PHPT. Genetic analysis revealed a novel mutation in exon 1 of CDC73. This report contributes to the understanding of the genetics of this rare syndrome. It also highlights the fact that HPT-JT should be considered and CDC73 mutation analysis should be performed in cases of early-onset PHPT associated with ossifying fibromas of the jaw.     

Modulation of Neuroimmune Responses on Glia in the Central Nervous System： Implication in Therapeutic Intervention against Neuroinflammation

It has long been known that the brain is an immunologically privileged site in normal conditions. Although the cascade of immune responses can occur as long as there is a neuronal injury or a potent immune stimulation, how the brain keeps glial cells in a quiescent state is still unclear. Increasing efforts have been made by several laboratories to elucidate how repression oi~ immune responses is achieved in the neuronal environment. The suppression factors include neurotransmitters, neurohormones, neurotrophic factors, anti-inflammatory factors, and cell-cell contact via adhesion molecules or CD200 receptor. This review discusses how these factors affect the cascade of cerebral immune responses because no single factor listed above can fully account for the immune suppression. While several factors contribute to the suppression of immune responses, activation of glial cells and their production of pro-inflammatory factors do occur as long as there is a neuronal injury, suggesting that some neuronal components facilitate immune responses. This review also discusses which signals initiate or augment cerebral immune responses so that stimulatory signals override the suppressive signals. Increasing lines of evidence have demonstrated that immune responses in the brain are not always detrimental to neurons. Attempt to simply clear off inflammatory factors in the CNS may not be appropriate for neurons in neurological disorders. Appropriate control of immune cells in the CNS may be beneficial to neurons or even neuroregeneration. Therefore, understanding the mechanisms underlying immune suppression may help us to reshape pharmacological interventions against inflammation in many neurological disorders.     

Characteristics of the Vδ2 CDR3 Sequence of Peripheral γδ T Cells in Patients with Pulmonary Tuberculosis and Identification of a New Tuberculosis-Related Antigen Peptide

Antigen-specific γδ T cells may play an important role in the immune response to Mycobacterium tuberculosis. However, little is known about the characteristics of the length distribution of the δ2-chain complementarity determining region 3 (δ2 CDR3) of the γδ T-cell receptor (TCR) in patients with active pulmonary tuberculosis (TB) on a large scale. In addition, M. tuberculosis-activated γδ T cells potentially inhibit intracellular mycobacterial growth, but phosphoantigen-activated γδ T cells do not. Only a few M. tuberculosis-related antigen peptides or proteins that are recognized by γδ TCR have been identified. Twenty-four healthy donors (HDs) and 27 TB patients were included in the present study. The gene-scanning technique found that the δ2 CDR3 length distribution patterns of γδ TCR in TB patients were perturbed, and each pattern included different predominant CDR3 sequences. The predominant δ2 CDR3 sequences of γδ TCRs, which originated from TB patients and HD γδ T cells that were stimulated by M. tuberculosis heat resistance antigen (Mtb-HAg), were used as probes to screen peptides recognized by γδ TCR using a phage display library. We identified four peptides that bound to the predominant δ2 CDR3 fragments and showed homology to M. tuberculosis genes in a BLAST search. Notably, one peptide was related to M. tuberculosis H37Rv (QHIPKPP), and this fragment was confirmed as a ligand for the γδ TCR. Two fragments, Ag1 and Ag2, activated γδ T cells from HD or TB patients. In summary, the δ2 CDR3 lineage of TB patients apparently drifts, and the predominant δ2 CDR3 sequence that recognizes M. tuberculosis may exhibit specificity. The identified M. tuberculosis-related antigen peptides may be used as vaccines or adjuvants for protective immunity against M. tuberculosis.     

DOCK2 Is a Microglial Specific Regulator of Central Nervous System Innate Immunity Found in Normal and Alzheimer’s Disease Brain

Neuroinflammation is a hallmark of several neurodegenerative diseases, including Alzheimer’s disease (AD). Strong epidemiological and experimental evidence supports the use of nonsteroidal anti-inflammatory drugs to reduce AD risk. However, poor outcome in clinical trials and toxicity in a prevention trial have shifted focus away from these cyclooxygenase (COX) inhibitors to seek additional therapeutic targets in the prostaglandin pathway. Previously, the prostaglandin E2 receptor, EP2, was shown to regulate neuroinflammation and reduce Aβ plaque burden in transgenic mice. Unfortunately, widespread EP2 distribution and a direct effect on COX2 induction make EP2 a less desirable target. In this study, we link dedicator of cytokinesis 2 (DOCK2) to the prostaglandin pathway in the brain. Additionally, we show that DOCK2 regulates microglial innate immunity independent of COX2 induction and that DOCK2⁺ microglia are associated with human AD pathology. Together, these results suggest DOCK2 as a COX2 expression-independent therapeutic target for neurodegenerative diseases such as AD.Innate immune activation of the central nervous system is associated with several neurodegenerative diseases including Alzheimer’s disease (AD).^1,2,3,4 The major cellular component of this response, activated microglia, demonstrates both beneficial and deleterious effects on surrounding neurons.^4,5,6,7,8,9 The deleterious effects include microglial secretion of a variety of molecules including prostaglandins (PGs) that can mediate paracrine neurotoxicity. Indeed, activation of the PG pathway has been linked with neurotoxicity in a number of cell culture and in vivo models.^{2,6,10,11,12,13} This is especially compelling because there are existing drugs that target the PG pathway, such as the cyclooxygenase (COX) inhibitors that inhibit PG production.Strong epidemiological evidence supports the efficacy of COX isozyme suppression in PG signaling by nonsteroidal anti-inflammatory drugs (NSAIDs) for AD therapy (reviewed in¹⁴). Recently, hard-gained knowledge about COX2 toxicity associated with NSAIDs has led academic and industry laboratories to pursue more specific targets.^15,16,17 Through a series of studies we and others have demonstrated the pro-inflammatory, pro-oxidative, and pro-amyloidogenic nature of the prostaglandin E2 receptor (EP2) in mouse brain or primary cultures from mouse brain, suggesting it as a potentially beneficial therapeutic target for AD.^4,9,18,19,20 While work to date with EP2 highlights a promising approach to PG-related therapeutics in neurodegenerative diseases, widespread organ and cellular distribution of EP make it a nonspecific therapeutic target. Moreover, EP2 activation regulates COX2 expression, at least in microglia, and so EP2 targeting may lead to a similar toxicity profile as relatively COX2-selective NSAIDs.^20,21,22,23The aims of this study were to discover and evaluate EP2-dependent regulators of microglial innate immune response that did not regulate COX2 expression. Indeed, we identified dedicator of cytokinesis 2 (DOCK2) expression as being nearly completely dependent on EP2 expression in microglia. DOCK2 was identified in 1999 as a member of the CDM family of proteins, which includes Caenorhabditis Elegans CED-5, human DOCK180, and Drosophila Melanogaster Myoblast City.²⁴ To date, the majority of studies concerning DOCK2 have shown it to act as a guanyl-nucleotide exchange factor (GEF), which positively regulates Rac- (a Rho family small GTPase) mediated cellular processes such as lymphocyte migration.^{24,25,26,27,28,29,30,31} The Rho family of small GTPases, including Rac, is known to be intimately associated with actin cytoskeleton processes as well as oxidative processes in phagocytic cells. In primary and immortalized microglial cell cultures, Rac1 activation has been shown to promote phagocytosis, including Aβ_1-42 clearance.^32,33 With the exception of DOCK2’s role in neutrophil chemotaxis, there has been no literature describing its function in phagocytic cells even though it has been implicated in macrophage phagocytosis and NADPH oxidation.^24,34,35Following our discovery, we further investigated the role of DOCK2 in microglial function relating to phagocytosis and neurotoxicity as well as regulation of COX2 expression. We also sought to establish relevance of DOCK2 expression to AD pathogenesis by evaluating its expression pattern in human brain. To date, there has been no literature providing evidence for DOCK2 expression or function in the brain. Our identification and subsequent characterization of DOCK2 in brain may highlight its potential as a microglial-specific, COX2-expression independent therapeutic target for neurodegenerative diseases, such as AD.     

First Description of an Extended-Spectrum-β-Lactamase-Producing Multidrug-Resistant Escherichia fergusonii Strain in a Patient with Cystitis

Extended-spectrum-β-lactamase (ESBL)-producing organisms have captured the attention of clinicians and laboratorians and are agents of nosocomial and community onset infections (J. D. Pitout and K. B. Laupland, Lancet Infect. Dis. 8:159-166, 2008). ESBLs in many enterobacteriaceae and in nonfermenting Gram-negative organisms have been described (K. Bush and G. A. Jacoby, Antimicrob. Agents Chemother. 54:969-976, 2010). We present the first case of a clinical isolate of multidrug-resistant Escherichia fergusonii expressing an extended-spectrum-β-lactamase (ESBL).     

Increased Circulating Th17 Cell Populations and Elevated CSF Osteopontin and IL-17 Concentrations in Patients with Guillain-Barré Syndrome

Purpose

Guillain-Barré syndrome (GBS) is an acute post-infectious immune-mediated demyelinating disease of the peripheral nervous system. Th17 cells and osteopontin (OPN) have been implicated in the development of autoimmune diseases, but little is known about their relationship and roles in the pathogenesis of GBS.

Methods

In this study, we used flow cytometry to evaluate peripheral numbers of Th17, real-time polymerase chain reaction to assay mRNA expression of RORγt, and enzyme-linked immunosorbent assay to determined OPN and IL-17 concentrations.

Results

The frequency of Th17 cells was significantly higher in the peripheral blood of acute-stage GBS patients comparison with other non-inflammatory neurological diseases (OND). In line with these observations, the levels of mRNA expression of RORγt in peripheral blood mononuclear cells and the concentrations IL-17 in both plasma and cerebrospinal fluid (CSF) were significantly higher in the acute-stage GBS than stable-stage GBS. OPN concentrations were significantly increased in the CSF of acute-stage GBS patients compared to OND. Circulating Th17 cell populations and CSF OPN levels, respectively, are correlated with GBS disability scale scores (GDSs), and there was a positive correlation between them.

Conclusion

In summary, our preliminary findings suggest that both Th17 and OPN may be associated with the pathogenesis of GBS.     

Quantitative Peripheral Blood Perturbations of γδ T Cells in Human Disease and Their Clinical Implications

Human γδ T cells, which play innate and adaptive, protective as well as destructive, roles in the immune response, were discovered in 1986, but the clinical significance of alterations of the levels of these cells in the peripheral blood in human diseases has not been comprehensively reviewed. Here, we review patterns of easily measurable changes of this subset of T cells in peripheral blood from relevant publications in PubMed and their correlations with specific disease categories, specific diagnoses within disease categories, and prognostic outcomes. These collective data suggest that enumeration of γδ T cells and their subsets in the peripheral blood of patients could be a useful tool to evaluate diagnosis and prognosis in the clinical setting.