bluuebunny/crossref_metadata_2025 huggingface dataset:
HIV-induced deletion of antigen-specific T cell function is MHC restricted
Authors: MANCA F , NEWELL A , VALLE M , HABESHAW J , DALGLEISH A G
Published: July 2010

When antigen-specific T cells are pulsed by antigen-presenting cells (APC) in the presence of HIV they are functionally deleted following subsequent exposure to syngeneic APC in the absence of HIV. Recombinant soluble HIV envelope (gp 120) is able to induce a similar effect which, unlike that induced by HIV, is reversible. Neither HIV nor gp120 affect the ability to respond to IL-2. Thus it is only antigen-specific responses involving the T cell receptor pathways and CD4/MHC class II interaction that appear to be inhibited by HIV-1 and gp120. Furthermore, the functional impairment caused by HIV-1 is specific to the T cells that respond to the antigen in co-culture with HIV, as there is no apparent effect on ‘bystander’-activated T cells specific for another antigen. Antigen-specific T cell lines may be deleted by A signalling mechanism which involves molecules other than gp120/CD4 but still requires MHC class II restriction.
Induction of intercellular adhesion molecule-1 (CD54) on human hepatoma cell line HepG2: influence of cytokines and hepatitis B virus-DNA transfection
Authors: VOLPES R , VAN DEN OORD J J , DESMET V J , YAP S-H
Published: July 2010

Human hepatocyte expression of intercellular adhesion molecule-1 (ICAM-1)(CD54) was studied in vitro by exposing the well differentiated human hepatoblastoma cell line HepG2 to various cytokines. In addition, hepatitis B virus (HBV)-DNA transfected HepG2 cells were also analysed. Expression of ICAM-1 on HepG2 cells was then revealed with an immunohistochemical procedure. Untreated HepG2 cells were unreactive, but showed strong cytoplasmic ICAM-1 immunoreactivity after treatment with interferon-gamma (IFN-γ). This induction was completely inhibited by addition of a neutralizing antibody directed to IFN-γ, IL-1, IL-6, tumour necrosis factor-α (TNF-α) and IFN-α used alone or in combination, did not induce ICAM-1 expression, neither did they inhibit the IFN-γ-induced expression of this adhesion molecule on HepG2 cells. Untreated hepatitis B virus-DNA transfected HepG2 cells expressed membranous ICAM-1. These results indicate that IFN-γ is the main cytokine trigger for ICAM-1 expression on HepG2 cells, suggesting that in areas of liver inflammation this adhesion molecule is up-regulated on hepatocytes by locally released IFN-γ. In addition, expression of ICAM-1 by hepatitis B virus-DNA transfected HepG2 cells suggests other, still unknown, triggering mechanisms in the induction of such adhesion molecules, for instance gene activation by viral genome, or autocrine virus-induced hepatocellular cytokine production.
Regulation of IL-2β receptor expression and β-chain mRNA by human thymocytes
Authors: REEM G H , HAN X , MARCELLI A
Published: July 2010

The high affinity form of the human IL-2 receptor (IL-2R) has two known components, the IL-2Rα (p55) and the IL-2Rβ chain (p75). We have previously shown that recombinant IL-2 (rIL-2) could induce the expression of the α-chain (p55) on T cells and thymocytes, and increase this expression following suboptimal activation with concanavalin A (Con A) in combination with IL-2. An increase in the accumulation of IL-2Rα-specific mRNA induced by rIL-2 in T cells and thymocytes had also been documented. We report here that the expression of IL-2Rβ on the cell surface can be demonstrated on human thymocytes by the binding of Mik β1, a MoAb directed against an epitope of the β-chain. The IL-2Rβ chain is constitutively expressed on freshly isolated thymocytes; this expression can be increased in thymocytes activated with Con A in combination with IL-2 or tetradecanoylphorbol 13-acetaie (TPA). Blocking the formation of high affinity receptors with a MoAb directed against the α-chain of the receptor results in an increase in the display of IL-2Rβ as evidenced by binding of MoAb Mik β1. The accumulation of IL-2Rβ specific mRNA is observed in freshly isolated thymocytes and it is increased in thymocytes cultured with rIL-2 alone, with Con A. and further enhanced by the addition of rIL-2 in combination with Con A or with TPA. Cyclosporine (CsA), which inhibits the accumulation of lymphokine-specific mRNA of thymocytes, does not inhibit the induction of the accumulation orIL-2Rβ-specific mRNA. This is analogous to its effect on the expression of the α-chain (p55), and the accumulation of α-chain-specific mRNA.
The expression of HLA-DR by monocytes from black and from white donors: different requirements for protein synthesis
Authors: MCPEEK M , SALKOWTTZ J , LAUFMAN H , PEARL D , ZWILLING B S
Published: July 2010

Epidemiologic data indicates that blacks may be more susceptible than whites to infection by Mycobacterium tuberculosis. Resistance to the in vivo to growth of Mycobacteria in mice correlates with the persistence of MHC class II expression by peritoneal macrophages. The expression of HLA-DR by human monocytes from different groups of individuals also differs. The increase in the expression of HLA-DR by monocytes that occurs upon in vitro culture was prevented by the protein synthesis inhibitor cycloheximide (CHX) in a majority of black donors. In contrast, the increase in HLA-DR expression by monocytes from the majority of white donors was unaffected.
MHC restriction of synovial fluid lymphocyte responses to the triggering organism in reactive arthritis. Absence of a class I-restricted response
Authors: HASSELL A B , PILLING D , REYNOLDS D , LIFE P F , BACON P A , GASTON J S H
Published: July 2010

Synovial fluid mononuclear cells (SFMC) from patients with reactive arthritis (ReA) show marked proliferative responses to preparations of the organism triggering the arthritis. Initial studies with MHC-specific MoAbs have indicated that a significant element of these proliferative responses is mediated by class II MHC-restricted CD4+ T cells. It is imperative to establish the presence or absence of a class I-restricted response, for two reasons. Firstly, the association of ReA with the MHC class I molecule. HLA B27, raises the possibility of there being a B27-restricted response to the triggering organism. Secondly, a number of the organisms associated with ReA are intracellular pathogens, whose antigens might be expected to be presented by class I MHC molecules. In an effort to identify a class I MHC-restricted pathogen-specific response in the SFMC of ReA patients, we have assessed the proliferative responses of SFMC depleted of CD4+ T cells. Responses were grossly diminished by CD4+ T cell depletion. We also investigated Chlamydia-specific cytotoxicity in the SFMC of patients with sexually acquired ReA in a system using productive chlamydial infection to produce both targets and effectors. Significant antigen specific cytotoxicity was not seen. These experiments do not provide evidence to support the existence of pathogen-specific responses by CD8+, class 1-restricted synovial fluid T cells in ReA.
Expression of antigen reactive with a monoclonal antibody to HTLV-1 P19 in salivary glands in Sjögren's syndrome
Authors: SHATTLES W G , BROOKES S M , VENABLES P J W , CLARK D A , MAINI R N
Published: July 2010

To examine the possible involvement of retroviruses in Sjögren's syndrome (SS), labial salivary gland sections from 99 individuals were probed with three MoAbs to core (gag) proteins of human T cell leukaemia virus-1 (HTLV-1) and two MoAbs to HIV-1. Sections from 31% of 39 patients with primary SS (pSS) contained an epithelial cytoplasmic protein reactive with a MoAb(197) to the p19 group specific antigen (gag) of HTLV-1. The antigen was also detected in samples from 24% of 17 patients with rheumatoid arthritis (RA) and SS. 21% of 14 patients with sicca symptoms and 12.5% of 16 patients with other connective tissue diseases. It was not found in the salivary glands of 13 normal controls. A second MoAb to p19 gag, a MoAb to the p24 gag of HTLV-1 and MoAbs to HIV-1 p17and p24 gags gave negative reactions. Serum antibodies to HTLV-1 were negative, confirming that the antigen was not part of HTLV-1. The antigen showed properties consistent with an endogenous retrovirus in that it was absent in healthy tissues or resting cells but inducible by stimulation with phytohaemagglutinin (PHA) or interferon-gamma (IFN-γ) It appeared to be distinct from the endogenous retroviral sequence HRES-1. These data suggest the presence of an endogenous retrovirus in salivary gland epithelium which could contribute to the chronic inflammation of SS.
Circulating intercellular adhesion molecule-1 (ICAM-1) antigen in sera of patients with idiopathic pulmonary fibrosis
Authors: SHIJUBO N , IMAI K , AOKI S , HIRASAWA M , SUGAWARA H , KOBA H , TSUJISAKI M , SUGIYAMA T , HINODA Y , YACHI A , ASAKAWA M , SUZUKI A
Published: July 2010

Intercellular adhesion molecule-1 (ICAM-1), a member of immunoglobulin supergene family with a five-domain structure, is known to play an important role in inflammatory diseases. An ELISA was developed using two MoAbs against human ICAM-1 in order to detect the soluble shedding ICAM-1 antigen in sera. We measured levels of circulating ICAM-1 antigen in sera of patients with idiopathic pulmonary fibrosis (IPF), pulmonary sarcoidosis, hypersensitive pneumonitis, bacterial and mycoplasmal pneumonia, and inflammatory diseases of other organs. The results clearly demonstrated that IPF had significantly high levels of circulating ICAM-1 in sera as compared with other disorders or normal controls. Moreover, immunohistochemical analysis with MoAb against human ICAM-1 disclosed that in IPF, the expression of ICAM-1 was intensively enhanced on alveolar epithelial cells. These results suggest that ICAM-1 may contribute to the pathogenesis of IPF.
Spontaneous development of pancreatitis in the MRL/Mp strain of mice in autoimmune mechanism
Authors: KANNO H , NOSE M , ITOH J , TANIGUCHI Y , KYOGOKU M
Published: July 2010

MRL/Mp mice are known to have autoimmune disease-prone genetic background, which contributes to the development of a lethal autoimmune disease at an early age in association with the lymphoproliferative gene, Ipr. In this study, we found that MRL/Mp mice, not bearing Ipr (MRL/Mp-+/+), spontaneously developed pancreatitis at a late stage of life, which was histopathologically characterized by destruction of pancreatic acinar cells with mononuclear cell infiltration. In female 34–38-weeks-old mice the incidence of pancreatitis reached 74%, whereas the male mice developed the disease with a reduced incidence, at a later stage of life and with a reduced severity. Cell infiltrates in the affected lesions were composed predominantly of CD4+ cells and to lesser extent Mac-2+ macrophages. Adoptive transfer of the spleen cells obtained from pancreatitis-bearing female mice generated pancreatitis in female normal mice, but not in the male mice. Transfer of the serum of pancreatitis-bearing mice failed to induce any pancreatic lesions. These findings indicate that pancreatitis in MRL/Mp-+/+ mice may be mediated by cellular autoimmune mechanism. This may present a useful concept for analysis of the developmental mechanisms of human chronic pancreatitis in an aspect of autoimmunity.
Elevation of activated γδ T cell receptor bearing T lymphocytes in patients with autoimmune chronic liver disease
Authors: WEN L , PEAKMAN M , MIELI-VERGANI G , VERGANI D
Published: July 2010

To study the possible role of T cells bearing the γδ T cell receptor (TCR) heterodimer in the pathogenesis of autoimmune chronic active hepatitis (AI-CAH) and primary sclerosing cholangitis (PSC) in children, we measured levels of γδ+ T cells in the peripheral blood, assessed the proportion of cells bearing the disulphide-linked (BB3+) and non-disulphide-linked (A13+) subtypes of the receptor, and studied the co-expression of TCR-γδ and the activation markers HLA-DR and IL-2 receptor (IL-2R), and the memory cell marker CD45RO. Percentage levels and absolute numbers of γδ+ T cells were higher in both groups of patients than in controls (P <0.01), mainly as a result of an increase in both percentage levels and absolute numbers of the A13+ subtype (P <0.001). Coexpression of IL-2R and TCR-γδ was not found in controls but was present in some patients with AI-CAH (four out of 17) and PSC (six out of 12) at low levels (median 2.3%, range 1.7–5.0%). Expression of HLA-DR on γδ+ T cells was similar in both groups of patients and controls. The majority of γδ+ T cells in children with AI-CAH and PSC also expressed CD45RO (74.7 ± 18.4% and 79.8±24.3%, respectively) at levels significantly higher than in controls (53.3±17.2%, P <0.01). These results suggest that autoimmune liver diseases in children are associated with an expansion and activation of γδ+ T cells in the peripheral blood, which may be important in the pathogenesis of these disorders.
IL-8 as a circulating cytokine: induction by recombinant tumour necrosis factor-alpha
Authors: SHERON N , WILLIAMS R
Published: July 2010

Tumour necrosis factor-alpha (TNF-α) is a pivotal cytokine at the centre of a cascade of cytokines and inflammatory mediators which modulate the host response to infection and trauma, and in particular the metabolic changes resulting in shock and subsequent multi-organ failure. The cytokine IL-8–predominantly an activator and chemotactic factor for circulating polymorphonuclear neutrophil leucocytes–is produced in response to TNF-αin vitro, and high circulating levels of IL-8 are found in septic primates. We have studied the release of IL-8 into the circulation of subjects with chronic hepatitis B undergoing a 10 week pilot trial of recombinant TNF-α (rTNF-α) therapy in doses of 15-100 μg/m2, A marked dose-dependent increase in plasma IL-8 levels was seen commencing at 30-60 min after the start of rTNF-α infusion and peaking between 2 and 3 h (mean peak level 4300 ng/l). The temporal pattern of IL-8 production exactly echoed that of IL-6, another component of the cytokine cascade, but peak plasma levels of IL-8 were up to 17 times higher than those of IL-6. This study confirms in vitro data suggesting that IL-8 is a component of the acute circulating cytokine cascade with a potential role in the modulation of the acute immune and metabolic response to infection and trauma.
T cell regulation of the chronic peritoneal neutrophilia during mycobacterial infections
Authors: APPELBERG R
Published: July 2010

Intraperitoneal infection of mice with mycobacteria induces the persistent mobilization of neutrophils to the infected peritoneal cavities. The recruitment of the neutrophils was mediated by the immune system since it was enhanced by immunization and reduced in T cell-deficient nude and SCID mice. Anti-mitotic treatments with cyclophosphamide or X-rays led to a reduction in the number of mononuclear cells in the peritoneal cavity of infected mice, followed by a reduction in neutrophil numbers despite the presence of a normal circulating pool of neutrophils. The depletion of T cells with antibodies during mycobacterial i.p. infection led to a reduction in the number of neutrophils. Such a reduction was more extensive if the antibodies were administered early. Our data suggest that T cells are partially involved in the direct recruitment of neutrophils during chronic mycobacteriosis but they also play a role in the priming of other cell types for the mobilization of these phagocytes.
Comparison of the properties of the CsA analogs monoacetyl CyC (o-acetyl-threonine2 cyclosporin) and methyl-alanyl CsA (N-methyl-L-alanyl6 cyclosporin); monoacetyl cyclosporin is immunosuppressive without binding to cyclophilin
Authors: EL ROUBY S , SHI Y , REEM G H
Published: July 2010

Cyclosporin (CsA) is an immunosuppressant which binds to cyclophilin (Cyp). The relationship between Cyp binding and immunosuppression has been questioned since one of the analogs of CsA, N-methyl-L-alanyl6 cyclosporin (methyl-atanyl CsA) binds to Cyp but is not immunosuppressive. We compared the immunosuppressive properties of CsA, methyl-alanyl CsA and o-acetyl-threonine2 cyclosporin (monoacetyl CyC), since monoacetyl CyC does not bind to Cyp when tested in cell-free assays and its immunosuppressive properties had not been tested. Cyp is a peptidyl-prolyl isomerase which is abundant in all human tissues, yet the activities of CsA are mostly confined to inhibition of T cell and thymocyte activation, and to neuro- and nephro-toxicity and are independent of inhibition of the isomerase. Activation of thymocytes and of T cells is regulated by the binding of a nuclear factor(s) (NFs) to the NF-AT region (– 285 to – 255) of the IL-2 promoter. We studied inhibition of binding to the NF-AT region of NFs derived from primary cultures of thymocytes treated with CsA or its analogs. In addition, we compared the effect of CsA and its analogs on the expression of the IL-2 gene in a stably transfected Jurkat-cell line (Fgl 5) which contains three copies of NF-AT and the reporter enzyme β-galactosidase; and on inhibition of proliferation induced by concanavalin A(Con A) or IL-2. We found that monoacetyl CyC which does not bind to Cyp is immunosuppressive by our criteria when tested in cultured cells due to either a different mechanism of action or to metabolic activation.
CD3+ CD57+ lymphocytes are not likely to be involved in antigen-specific rejection processes in long-term allograft recipients
Authors: REIPERT B , SCHEUCH C H , LUKOWSKY A , REINKE P , FIETZE E , DÖCKE W D , STAFFA G , CZERLINKSI S , HETZER R , VOLK H D
Published: July 2010

Cytofluorometric investigation of peripheral blood lymphocytes in 380 long-term (> 1 year post-transplantation) allograft recipients showed a significant increase in the proportion of CD3+57+ lymphocytes (> 20%) in 20% of patients with renal allografts, 66% of patients with cardiac allografts and 44% of patients with liver allografts. Most of these CD3+ 57+ cells expressed the CD8 antigen and a variable proportion the HLA-DR antigen. A retrospective analysis showed a poorer prognosis for the clinical outcome in those patients with elevated numbers of CD3+57+ cells in peripheral blood. However, CD57+ lymphocytes could rarely be detected in renal infiltrates by immunohistology. Using the Southern blot technique to analyse the T cell receptor rearrangement of separated CD57+ cells, no clonal or oligoclonal expansion of T cell clones could be detected. Nevertheless, there might be a bias towards the use of particular TCR-Vβ gene families in at least some patients, as shown by analysis with monoclonal antibodies. In summary, CD57+ T cells are not likely to be directly involved in the rejection process. The data support the idea of a polyclonal and/or superantigendriven expansion, but not of an antigen-driven expansion of these cells.
T cell redistribution kinetics after secondary infection of BALB/c mice with respiratory syncytial virus
Authors: KIMPEN J L L , OGRA P L
Published: July 2010

BALB/c mice were infected intranasally with live respiratory syncytial virus (RSV) and reinfected 4 weeks later. At regular intervals thereafter groups of animals were killed and T cell subsets were determined in blood, spleen and bronchoalveolar lavage (BAL) with flow cytometry employing T cell subset-specific MoAbs. Total lymphocyte counts in the peripheral blood decreased 1–3 days after infection, returning to preinfection levels on day 8 (P= 0.0111). Simultaneously, a marked increase of lymphocytes was noted in the BAL, reaching a maximum at day 8 (P < 0.0001). Both CD4+ and CD8 + T cells decreased in the blood on day 1–3 (P < 0.0097 and P = 0.003 respectively), and increased in the BAL progressively towards a maximum at day 8 (P < 0.0001). In BAL, CD4+ cells increased 35-fold and CD8+ cells 27-fold during the first week after reinfection. On the other hand, in the spleen a significant decline of CD4+ and CD8+ cells was noted 1 day post-infection (P= 0.0002). It is concluded that a strong T cell redistribution response among systemic and mucosal tissues occurs after reinfection with RSV. The kinetics of this response differ both quantitatively and qualitatively from the T cell response after primary infection. The magnitude of cell traffic is more pronounced in blood, spleen and BAL than after primary infection. CD4+ T cells are more intensively distributed to the lungs than after primary infection.
No restriction of intrathyroidal T cell receptor Vα families in the thyroid of Graves' disease
Authors: McINTOSH R S , WATSON P F , PICKERILL A P , DAVIES R , WEETMAN A P
Published: July 2010

Recently it has been reported that the intrathyroidal T cells in Graves'disease display restriction in Vα T cell receptor (TcR) gene family usage, although this is not found with TcR Vβ gene families in the same individuals. We have performed a qualitative analysis of TcR Vα family usage in 12 patients with Graves'disease by reverse transcription and polymerase chain reaction (PCR) amplification of RNA extracted from isolated, unstimulated intrathyroidal lymphocytes and from snap-frozen whole thyroid specimens. No restriction was observed, with 10–15 Vα gene families being amplified in all cases. The pattern of usage was similar to that in peripheral blood lymphocytes derived from normal subjects (n = 3) and from patients with Graves'disease (n = 3), as well as that present in the thyroids of patients with non-autoimmune toxic multinodular goitre (n = 4). These results indicated that there is no marked restriction of the unselected intrathyroidal T cell population in patients with Graves'disease who have been treated with antithyroid drugs.
High frequency of spontaneous interferon-gamma-producing cells in human tonsils: role of local accessory cells and soluble factors
Authors: QUIDING M , GRANSTRÖM G , NORDSTRÖM I , FERRUA B , HOLMGREN J , CZERKINSKY C
Published: July 2010

The frequency of mononuclear cells (MNC) spontaneously secreting interferon-gamma (IFN-γ) has been examined in freshly isolated cell suspensions from human palatine tonsils. Two-site reverse enzyme-linked immunospot (ELISPOT) analyses, involving short term (20 h) incubation of MNC in the absence of any added exogenous stimulus, revealed that tonsillar MNC suspensions contain exceptionally large numbers of cells secreting IFN-γ. No significant differences were observed when comparing the frequency of IFN-γ-producing cells between cell suspensions obtained from hyperplastic and tonsillitis specimens. Cell-sorting experiments disclosed that spontaneous tonsillar IFN-y production was essentially contributed by CD4+ T cells, and required the presence of accessory cells and/or soluble factors to be detected. Thus, depletion of plastic adherent cells or monocytcs from the tonsillar MNC suspensions resulted in reduced numbers of detectable IFN-γ-secreting cells. Addition of very small numbers of autologous monocytes restored spontaneous IFN-γ production in tonsillar MNC cultures depleted of monocytes. Neutralization of endogenous IL-1β and IL-2, as well as blocking of the IL-2 receptor, also decreased IFN-γ production from unfractionated tonsillar cells. Addition of exogenous IL-1β restored IFN-γ production in cultures of tonsillar MNC depleted of plastic adherent cells. Furthermore, IL-1β synergized with IL-2 by increasing intracellular as well as cell-free levels of IFN-γ in cultures of unfractionated tonsillar MNC. This study further establishes that the tonsils are highly active immunological organs containing large numbers of T cells spontaneously producing IFN-γ whose detection is contingent upon the presence of functional accessory cells. It also demonstrates that concomitant production of IL-1β and IL-2 occurs in tonsils and is necessary to maintain ongoing synthesis and extracellular accumulation of IFN-γ in these organs.
Increased IL-6 gene expression and production in patients with common variable immunodeficiency
Authors: PANDOLFI F , PAGANELLI R , OLIVA A , QUINTI I , POLIDORI V , FANALES-BELASIO E , GUERRA E , AIUTI F
Published: July 2010

We have studied IL-6 gene expression and production by in vitro stimulated peripheral blood mononuclear cells (PBMC) isolated from common variable immunodeficiency (CVI) patients. A strong hybridization signal for the IL-6 probe was observed in mRNA extracted from phyto-haemagglutinin (PHA)- and PHA/phorbol myristate acetate (PMA)-stimulated PBMC from most of 12 CVI patients analysed. IL-6 production by PHA-stimulated PBMC from 28 CVI patients was evaluated in ELISA and found to be significantly (P < 0.0001) higher than in normal controls. IL-6 production, however, did not correlate with the lymphocyte populations examined, nor with the absolute number of monocytes. We have also showed that IL-6 was able to increase IgM secretion by several Epstein Barr virus (EBV)-transformcd cell lines derived from both normal donors and CVI patients, but it failed to modify substantially the amounts of IgM and IgG produced in vitro by PBMC derived from CVI patients and activated with pokeweed mitogen (PWM) or anti-IgM. Our data indicate that IL-6 gene expression and production is increased in CVI, but CVI cells do not respond to IL-6 with increased production of immunoglobulin.
Increased epithelial expression of HLA-DQ and HLA-DP molecules in salivary glands from patients with Sjogren's syndrome compared with obstructive sialadenitis
Authors: THRANE P S , HALSTENSEN T S , HAANAES H R , BRANDTZAEG P
Published: July 2010

Salivary gland specimens from 10 patients with primary Sjogren's syndrome (pSS) were examined by two-colour immunofluorescencc with various combinations of monoclonal and polyclonal antibody reagents of the following specificities: human leucocyte antigen (HLA) class I and II (DR, DP and DQ). CD3, CD45 (leucocyte common antigen), various cytokeratins, and factor VHI-related antigen. Tissue specimens from 10 normal glands and 10 glands with obstructive sialadenitis (no known autoimmunity) served as controls. Only some intercalated ducts and scattered acini of the normal major glands expressed HLA class II determinants (< 5% of total epithelial area); the relative proportion of positive elements indicated differential expression (DR> DP> DQ). SS glands contained substantial T cell infiltrates and increased numbers of activated (DR+) T cells; adjacent epithelium showed extensive differential expression of HLA class 11 determinants (DR> DP> DQ). Glands with obstructive sialadenitis showed similarly increased epithelial expression of HLA-DR but with surprisingly small amounts of concomitant H LA-DP and -DQ expression. Epithelial HLA class II expression probably depends on cytokines as an inductive event, which is not unique for SS but particularly prominent in this disorder. Our results suggest that epithelial expression of HLA-DP or -DQ, rather than -DR. might be a prerequisite for the autoimmune process of SS to develop in genetically susceptible individuals.
Lupus autoantibodies discriminate between the highly homologous Sm polypeptides B/B' and SmN by binding an epitope restricted to B/B'
Authors: HUNTRISS J D , LATCHMAN D S , WILLIAMS D G
Published: July 2010

The ubiquitous Sm polypeptides B/B’ (28 and 29 kD) and the highly homologous tissue-specific Sm N polypeptide (29 kD) share several autoepitopes recognized by systemic lupus crythematosus (SLE) sera. Previous studies on the antigenicity of nuclear antigens recognized by human autoantibodies have not discriminated between ubiquitous and tissue-specific forms. We set out to examine whether a tissue-specific nuclear antigen, Sm N. is autoantigenic in SLE by comparing the immunoreactivity of the most unique sequences in this polypeptide. Synthetic peptides from the two regions of least sequence homology that occur between Sm N and Sm B/B', a dodccamer (amino acid residues 179–190 containing five substitutions) and an undecamer (residues 203–213 containing four substitutions) were coupled to a carrier protein. These conjugates were used to quantify IgG anti-peptide antibodies in sera from patients with SLE. Of 43 sera with anti-Sm specificity, six bound to the B/B’ 179-190 peptide but not to the N version. None of 17 anti-Sm-negative SLE sera bound these peplides. The second region of least sequence homology between N and B/B’ (203–213) was not antigenic. Our data suggest that a subset of SLE patients with anti-Sm reactivity have IgG autoantibodies capable of discriminating between Sm N and SmB/B' polypeptides by binding a previously unreported SmB/B'-specific autoepitope. The data also indicate that brain and heart-specific anti-Sm antibodies do not exist in SLE sera, suggesting that these tissues do not participate in the induction or maintenance of the autoimmune anii-Sm response.
Time-course of adhesion molecule expression in rectal mucosa of gluten-sensitive subjects after gluten challenge
Authors: ENSARI A , AGER A , MARSH M N , MORGAN S , MORIARTY K J
Published: July 2010

Adhesive interactions between endothelium and circulating ceils, such as monocytes, neutrophils and lymphocytes, are crucial for localizing the inflammatory response. We investigated the inflammatory response of rectal mucosa to local gluten challenge as a dynamic model of antigen-induced tissue injury, during which the expression of adhesion molecules on leucocytes and endothelial cells could be sequentially observed. Expression of ELAM-I, lCAM-1 and VCAM-1 was monitored in 10 treated and eight untreated patients with gluten sensitivity (eoeliac disease), and in five disease controls for up to 4 h (short challenge), while a further seven treated coeliacs were monitored for up to 24 h (Iongchallenge) following reetal gluten challenge. In the former, Ihc expression of VCAM-1 and ELAM-I was significantly raised 4 h after gluten challenge compared with controls, VCAM-1 and ELAM-l expression was also increased in mucosac of treated patients. but to a lesser extent, VCAM-1 expression continued to increase for up to 24 h after gluten, while ELAM-l had begun to wane by 4 h, reaehing basal levels by 24 h, In eontrast, the expression of ICAM-1 did not change in any of the disease groups studied. These findings relate to significant increases in lymphocytes (CD3+ cells) after 8 h, and neutrophils (CD15+ cells) after 4h in the lamina propria. This approach has permitted novel studies of the infiammatory response to a defined antigen in sensitized (gluten-sensitive) human patients.
The human T cell receptor Vβ repertoire of normal peripheral blood lymphocytes before and after mitogen stimulation
Authors: WONG F S , HIBBERD M L , WEN L , MILLWARD B A , DEMAINF A G
Published: July 2010

Milogen stimulation of T cells in vitro has been employed in the analysis of the T cell antigen receptor (TCR) repertoire and as a method of generating T cell lines and clones. It has been suspected for some time that mitogen stimulation may bias the repertoire. We have addressed this problem employing a semi-quantitative technique utilizing the polymerase chain reaction (PCR) and flow cytometry. Using this PCR method and a panel of primers to 22 Vβ subgroups, the Vβ repertoire of both unstimulated and phytohaemagglulinin (PHA)-stimulated peripheral T cells from eight healthy individuals was investigated. The samples were also analysed by flow cytometry using anti-Vβ2, Vβ5 and Vβ8 MoAbs. A significant increase in the expression of Vβ6, Vβ7.2 and Vβ 10.1 was found in all eight samples of PHA-stimulated T cells compared with unstimulatcd T cells using the PCR method. In contrast, no differences were found between unstimulaled and PHA-stimulated T cells by flow cytometry. These results question the validity of using milogen-stimulated T cells to investigate TCR gene usage.
Expression of glutamic acid decarboxylase (GAD) in the α, β and δ cells of normal and diabetic pancreas: implications for the pathogenesis of type I diabetes
Authors: VIVES-PI M , SOMOZA N , VARGAS F , ARMENGOL P , SARRI Y , WU J Y , PUJOL-BORRELL R
Published: July 2010

One of the paradoxes of insulin-dependent diabetes mellitus is that the destruction of the pancreatic islets’ endocrine cells is restricted to the insulin-producing β cells, whereas the main autoantibodies, islet cell antibodies (ICA), are directed against all endocrine islet cells. GAD has recently been proposed as the main target of the humoral and cellular autoimmune attack to the islets, and since in rat pancreas this enzyme was expressed only in the β cells, this provided an explanation for the cell specificity of the destructive process. The finding of GAD-positive cells in the islets of two diabetic patients, one of whom had completely lost the β cells, led us to study in detail thedistribution of GAD in normal human islet ceils using a panel of GAD aniiscra and the double indirect immunofluorescence technique on cryostat sections, monolayer cultures and cytosmears. The results showed that GAD is present not only in the cytoplasm of β cells but also in 69% of the α and 27% of the δ cells. GAD was not present, however, on the surface of the islet cells. These results suggest that the cellular distribution of GADcan not by itself explain the selectivity of β cell destruction in insulin-dependent diabetes mellitus.
Pinealectomy ameliorates collagen II-induced arthritis in mice
Authors: HANSSON I , HOLMDAHL R , MATTSSON R
Published: July 2010

To extend our previous findings that exposure to constant darkness (stimulation of endogenous melatonin release) as well as treatment with exogenous melatonin magnifies the severity of collagen-induced arthritis in mice, we have examined the effects of melatonin cutback by removing the pineal gland. Two strains of mice, DBA/1 and NFR/N, were subjected to surgical pinealectomy. The melalonin levels in sera were reduced by approximately 70% by the pinealectomy compared with the corresponding sham-operated controls. After 3–4 weeks of rest the mice were immunized with rat type II collagen to induce autoimmune arthritis, and the animals were kept in constant darkness during the experiments. In comparison with the controls, all groups of pinealectomized mice showed reduced severity of the arthritis by means of (i) a slower onset of the disease, (ii)a less severe course of the disease (reduced clinical scores), and (iii) reduced serum levels of anti-collagen II antibodies. These effects were not significant in all experiments, but the trends were always the same. Thus, the present results strengthen the hypothesis that high physiological levels of melatonin (which can be induced by exposure to darkness) stimulate the immune system and cause exacerbation of autoimmune collagen II arthritis, while inhibition of melatonin release (pinealectomy or exposure to light) has a beneficial effect.
Adjuvant treatment increases the resistance toMycobacterium aviuminfection of Mycobacteria-susceptible BALB/c mice
Authors: CASTRO A P , ÁGUAS A P , SILVA M T
Published: July 2010

We have investigated thc effect of inflammation on host resistance against infection by Mycobacterium avium. an atypical mycobactcria species that is responsible for life-threatening opportunistic infections in AIDS patients. Inflammation was induced in BALB/c mice by two intraperitoneal injections of mineral oil (Freund's incomplete adjuvant, FIA). The BALB/c strain was chosen because it is naturally susceptible to Myco. avium infection. One week after the second FIA injection, the BALB c mice were infected intravenously with 26 ± 106Myco. avium bacilli: at this time, the mice showed systemic granulocytosis because of the FIA injections. The kinetics of the murine infection was determined during 3 months by quantification of Myco. avium loads in the major target organs (liver and spleen) of the mycobacteria. The FIA treatment resulted in a significant decrease in the growth of Myco. avium in the infected BALBx mice. This enhancement in host resistance to Myco. avium infection lasted for 2 3 months. In contrast with BALB/c animals. C3B mice (naturally resistant to Myco. avium infection) did not show an increased anti-Myco. avium action in association with the FIA treatment. The anlimycobaeterial effect of the FIA injections in BALBx mice was compared with that produced by the injection of mycobacterial antigens (heat-killed Myco. tuberculosis) added to the mineral oil (i.e. Freund's complete adjuvant, FCA). The FCA treatment resulted in strong and sustained enhancements in the microbicidal capacities of BALB/c. and also of C3H mice. Data obtained with mutant athymic BALB/c mice revealed that the anti-Myco. avium effect of the FCA treatment was T cell-dependent. Our results indicate that: (i) non-immune inflammatory stimulation (FIA) of Myco. avium-susceptible hosts is able to cause a significant, albeit transient, increase in the resistance to Myco. avium infection; (ii) this protective effect is enhanced if heat-killed mycobacteria arc added to the phlogistic agent (FCA). i.e. if a T cell-dependent response is induced: and (iii) systemic increase in the number of circulating granulocytes may help host defence against Myco. avium infection.
Sera from patients with rheumatic diseases recognize different epitope regions on the 52-kD Ro/SS-A protein
Authors: BOŽIČ B , PRUIJN G J M , ROZMAN B , VAN VENROOIJ W J
Published: July 2010

Patients suffering from systemic lupus erythematosus (SLE) or Sjögren's syndrome (SS) often contain autoantibodies directed to the Ro(SS-A) complex. In this study the antigcnic determinants on two of the components of the Ro complex, i.e. the Ro60 and the Ro52 polypeptides, were investigated. Anti-Ro+ sera were selected by counter-immunoelectrophoresis. Depending on the detection method. 59–68% of the SLE patients produced anti-Ro but not anti-La antibody, while 72–81 % of the SS patients produced both anti-Ro and anti-La antibody. Immunoprecipitation of recombinant Ro-proteins showed that 61 sera (87%) were reactive with both Ro proteins, seven sera with Ro60 only, one serum with Ro52 only, and one serum did not precipitate the proteins at all. The anti-Ro60 reactivity of human sera is strongly associated with the native form of Ro60. suggesting that conformational autoepitopes are an important feature of Ro60. In the case of Ro52, frequently the residues located between amino acids 216 and 292 were essential for reactivity with the antibodies. With 70% of the lupus sera tested this appeared to be the only region important for reactivity. The antibodies of SS patients generally recognized multiple B cell epitopes located between amino acids 55 and 292. The results of this study indicate that the antigenic determinants on Ro52 are different for autoantibodies produced by lupus patients compared with those of SS patients.
CD21-CD23 ligand pair expression in children with allergic asthma
Authors: RABATIĆ S , GAGRO A , MEDAR-LASIĆ M
Published: July 2010

The CD23 antigen, a low affinity receptor for IgE, was recently shown to interact with another ligand, CD21, and the pairing of these molecules is important in T cell-B cell interaction and control of IgE production. Here, we analysed the expression of CD21 and CD23 on CD4+ and CD20+ lymphocytes in 25 allergic children and 12 age-matched non-allergic controls. Both the percentage (P<0.01) and the absolute number (P<0.00l) of CD23+ cells were increased in allergic children. There was no difference of CD21+ cells. Double positive CD4+CD23+ cells (2.5%) were only detected in one patient, in others all CD23 being expressed on B cells. The CD21 antigen was expressed only on B cells. Furthermore, allergic children had an increased mean fluorescence intensity of both the CD21 (P<0.00l) and the CD23 (P<0.001) receptor. To analyse the possible difference in B cell subsets expressing CD21 and CD23 antigens, three-colour fluorescence analysis was performed. In allergic children the subset of CD20+CD21− cells expressed more CD23 than in controls (P<0.001). These results may mean an impaired expression and possibly regulation of CD21-CD23 interaction in allergic conditions.
Antigen-presenting capacity of macrophages and dendritic cells in the peritoneal cavity of patients treated with peritoneal dialysis
Authors: BETJES M G H , TUK C W , STRUIJK D G , KREDIET R T , ARISZ L , BEELEN R H J
Published: July 2010

In this study the antigen-presenting capacity of human peritoneal cells and the influence of continuous ambulant peritoneal dialysis (CAPD) were studied. On average 6% of the peritoneal cells were dendritic cells (DC), with no difference between CAPD and control peritoneal cells. DC were enriched by selecting for non-adherent, Fc receptor-negative, low density cells. A typical spot-like CD68 positivity was seen in DC, in contrast to the pancytoplasmic staining pattern in macrophages. Peritoneal DC morphologically and functionally showed features of cells belonging to the DC lineage. Peritoneal DC were superior antigen-presenting cells for both allo-antigen, and Candida albicans antigen or purified protein derivative. CAPD peritoneal macrophages were two- to threefold better stimulator cells for allogeneic T cells compared with control macrophages. The level of integrins/adhesins or MHC class I or II, as measured semi-quantitatively on the FACS, could not account for this phenomenon. In addition, a double chamber system showed that dialysate-activated macrophages produced soluble factors that could enhance DC-induced allogeneic T cell proliferation. In conclusion, human peritoneal cells contain a relatively high percentage of classical DC. CAPD treatment does not impair the antigen-presenting capacity of peritoneal cells, but instead up-regulates the allo-antigcn-presenting capacity of peritoneal macrophages.
Macrophage depletion decreases IgG anti-DNA in cultures from (NZB · NZW)F1 spleen cells by eliminating the main source of IL-6
Authors: ALARCÓN-RIQUELME M E , MÖLLER G , FERNÁNDEZ C
Published: July 2010

We have studied ihe rote of macrophages in the produclion of IgG anli-DNA autoanlibodies by (NZB × NZW)F1 tnice(B/W). One of the main features of the syslemic lupus cryibematosus(SLE)-like disease that aftects these mice, h ihe presence of circuialing IgG autoantibodies and immune complexes, which lead lo renal failure and death by the age of 8–9 months. IgG autoantibodies are produced without in vitro siimulallon by lolal spleen eells from these miee when they reach tbe age of 6 monlhs. We have demonstrated ihat IL-6 increases ihe production of IgG autoantibodies in cultures of splenic purified B cells from the old B/W miee. The aim of this study was to show the involvement of macrophages in the production of IL-6 and consequently in the produclion of IgG anti-DNA antibodies in ritro. We show thai elimination of the macrophages by different treatments led to reduction of the content of IL-6 in ihe supernalants as well as of IgG anti-DNA autoantibodies. Addition of fresh, splenic or peritoneal macrophages restored the produclion of autoantibodies in macrophage-depleted cultures from old B/W miee. There were no ditferences in the capacity of IL-6 produelion between macrophages from old or young B/W miee. but an imporiani difference was observed between peritoneal and splenic maerophages, where the former produced mueh higher levels ol IL-6, and eonsequently were more potent inducers of IgG autoantibodies. The present results reinforee Ihe role of macrophages and lL-6 in Ihe production of IgG anti-DNA autoantibodies in B/W mice. The implieations of these results in the pathogenesis of the disease are discussed.
Prognostic value of serum immunoglobulin A antibodies to pol gene products during HIV-1 infection
Authors: QUESNEL A , POZZETTO B , MOJA P , GRATTARD F , LUCHT F R , TOURAINE J L , GAUDIN O G , GENIN C
Published: July 2010

Serum specimens from 66 HIV-t-infected subjects were tested by ELISA for the presence of IgA antibodies to HIV-t:44 samples were found positive and 37 were confirmed by immunoblot. In these subjects, the presence of anti-HIV IgA antibodies was studied in relation to the total count of circulating CD4+ lymphocytes and to the level of serum IgA. A significative correlation (P < 0·03) was found between the absence of IgA to the subunit p68 of the reverse transcriptase and a count of CD4+ cell < 400/mm3 or total IgA level over 4–25 g/l. The same pattern was observed for the IgA antibodies to the p52 subunit but the association was just not significant (P < 0·07). No significant decrease was noted for the IgA directed towards the other proteins of HIV-1, especially the products of the gag gene.
Differential requirements for HIV-1 replication in naive and memory CD4 T cells from asymptomatic HIV-1 seropositive carriers and AIDS patients
Authors: CAYOTA A , VUILLIER F , SCOTT-ALGARA D , FEUILLIE V , DIGHIERO G
Published: July 2010

One of the major routes for modulating HIV-1 expression by infected T cells is through the control of transcription initiation from the HIV-1 long terminal repeat (LTR), which is regulated either by ils own viral gene products or by several cellular DNA-binding proteins induced during T cell activation. Previous work reported preferential HIV-1 infection and replication of memory CD4 T eells from infected individuals, which was explained either by a higher viral burden of this subset or by differences between naive and memory cells in the activation of the general transcription machinery involved in HIV-1 replication. In this work, we have studied HIV-1 replication by highly purified naive and memory CD4 T eells from asymptomatic seropositive carriers (ASC) and AIDS patients following different activation signals. Our results demonstrate that viral replication in memory cells from ASC was observed after mitogenic (phytohaemagglutinin (PHA) and/or phorbol myristate acetate (PMA)) recombinant tumour necrosis factor-alpha (rTNF-α) and CD3-mediated activation. In contrast, in naive subsets, early viral replication was almost exclusively observed upon CD3-mediated activation. AIDS patients are characterized by similar levels of viral replication in both subsets after PHA and soluble or immobilized anti-CD3 MoAb activation. However, naive subsets from AIDS patienis still displayed differential requirements since they failed to replicate HIV-1 after treatmenl with PMA and rTNF-a. Taken together, these results provide evidence thai HIV-1 replication in CD4+ T cells from infected individuals is a function of the differentiation stage of the eells, the disease stage of the patient and the aetivation signal employed.
Detection of glomerular-binding immune elements in murine lupus using a tissue-based ELISA
Authors: BERNSTEIN K , BOLSHOUN D , GILKESON G , MUNNS T , LEFKOWITH J B
Published: July 2010

The glomerulonephritis in systemic lupus erythemalosus (SLE) is presumably triggered by ihe binding of circulating immune elements (autoantibodies and immune complexes) to the glomerulus; however, the nature of these elements is unclear. In order to detect and characterize such elements, we developed an ELISA using whole intact glomeruli as the substrate. With this assay, glomerular binding activity (GBA) was detected in the serum of MRLlpr, NZB × W, and B × SB mice, but not in non-autoimmune BALB/c mice. Less activity was present in the serum of C3H lpr, C57B1/6J Ipr and AKR lpr animals which develop signs of autoimmunity but only modest renal disease. The GBA in MRLlpr mice contained IgG (subclasses 1, 2a and 2b), but not IgG3. IgM. igA, orC3. GBA was not significantly decreased by preadsorption of MRL lpr serum by DNA-agarose (although anti-DNA antibodies were). Binding activity in serum, however, was diminished by DNAase treatment. Fractionation of MRL lpr serum over a molecular sizing column showed that GBA eluled in a broad peak. GBA bound to the glomerulus ex vivo in a tissue-specific fashion and was enriched in renal eluates relative to serum in vivo. In sum, the binding activity detected by this assay appeared to be a heterogeneous entity (possibly in part immune complexes containing DNA) which bound specifically to the glomerulus and which appeared to parallel the presence of renal disease. This novel assay system may help elucidate the pathogenesis of SLE nephritis and have utility as a disease marker.