bluuebunny/crossref_metadata_2025 huggingface dataset:
Binding Properties of Radiolabeled Basic Protein of Myelin: Reassessment in Relation to Diagnostic Immunoassays
Authors: BERNARD C. C. A. , SYMINGTON G. R. , MACKAY I. R.
Published: August 2010

The binding of radioiodinated basic protein of myelin ([125I]BPM) to a sheep lymphocyte cell pellet, sheep erythrocytes, and cell‐free tubes used in the assay was investigated as a possible diagnostic procedure in multiple sclerosis. [125I]BPM apparently bound to 5 × 106 sheep lymphocytes incrementally with no plateau, up to 300 ng, and also to sheep erythrocytes: when cells were transferred to fresh tubes, over 90% of the radioactivity remained (in the original tube, regardless of the tube surface. Various substances, including BPM and unrelated basic proteins, competitively inhibited the binding of basic protein of myelin to sheep cells and assay tubes. Binding was inhibited by sera from patients with multiple sclerosis, but equally so by normal sera. The large capacity of BPM to bind nonspecifically could limit its use in the above type of binding assay and would need to be allowed for in conventional radioimmunoassays.
Studies of Antibody‐Dependent Cytotoxicity in a Plaque Assay: Evidence of Human Monccyte‐Like Effector Cells
Authors: THORSTEINSSON L. , RØLAND S. S. , NATVIG J. B.
Published: August 2010

Two different methods for evaluating ‘in vitro’ cytotoxicity against antibody‐coated target cells mediated by mononuclear leukocytes were compared. One was a plaque assay for identification of the cytotoxic cell and the other the classical chromium release assay for antibody‐dependent cytotoxicity (ADCC). A marked decrease in plaque‐forming cells (PFC) was observed in a cell suspension depleted of peroxidase‐positive cells and cells with membrane‐bound Ig (B lymphocytes) by fractionation on a nylon fiber column. In contrast, the ADCC activity was considerably increased by these depletions. A similar effect was obtained by removal of phagocytic cells with iron. These results, together with the observations after depletion of E RFC (T lymphocytes) or EA‐RFC (Fc‐receptor‐bearing cells), suggest that the PFC in the assay system used were of monocytic origin and different from the cells responsible for the ADCC.
A Note on the Interpretation of Identity Reactions in Immunoelectrophoresis
Authors: DANIELSEN M. , SJÖSTRÖM H. , NORÉN O.
Published: August 2010

Immunoelectrophoretic methods, used in studies of the tissue specificity of two membrane‐bound peptidases obtained from pig, were observed to produce new types of reactions resembling those of partial immunochemical identity. In addition, the results obtained by fused rocket and rocket‐line immunoelectrophoresis suggested that the unshared antigenic determinants were situated on the heterologous antigens. When analyzed in the immunodiffusion system, the antigens showed a reaction of total immunochemical identity. Zone electrophoresis of the antigens demonstrated large differences in electrophoretic mobility. Neuraminidase treatment of the antigens almost abolished these differences, and the antigens now exhibited almost complete antigenic identity, suggesting that the precipitate patterns observed arose from the mobility differences.
Inhibition of B‐Cell Function by Concanavalin‐A‐Induced Suppressor Cells
Authors: SHAND F. L. , IVANYI J.
Published: August 2010

The in vitro immune response of normal spleen cells to the thymus‐independent antigen dinitrophenylated levan (DNP‐LE) was found to be inhibited by suppressor cells induced previously by concanavalin A (Con A) in vitro. At various suppressor to target cell ratios, the level of suppression observed was comparable to that seen in anti‐sheep erythrocyte (SRBC) responses. Consequently, it is suggested that B cells constitute a direct target for Con‐A‐induced suppressor cell activity.
Interaction Between a Synthetic Polypeptide, TIGAL, and Fc Receptors on Non‐Bursa‐Derived Chicken Lymphoid Cells
Authors: CRONE M. , JENSENIUS J. C. , KOCH C.
Published: August 2010

Autoradiographic studies have shown that radioiodinated TIGAL binds in vitro to a small but varying fraction of lymphoid cells from bursectomized, agammaglobulinemic chickens, whereas no binding of radioiodinated TGAL or a variety of other radioiodinated antigens can be observed. The binding of [125I]TIGAL is inhibited by antigen‐antibody complexes, Radioiodinated antigen‐antibody complexes are bound to a similar proportion of the lymphoid cells from bursectomized chickens, and this binding is inhibited by preincubation of the cells with un labeled TIGAL but not with TGAL. These results indicate a cross‐reaction at the level of Fc receptors between determinants on TIGAL and on IgG.
Human Leukocyte Migration Inhibitory Factor (LIF)
Authors: BENDTZEN K.
Published: August 2010

Recently reported experiments suggest that human leukocyte migration inhibitory factor (LIF) has properties of an esterase and a protease with substrate specificities directed against arginine esters and amides. Also reported previously, the synthetic phosphodiester bis‐p‐nitrophenyl phosphate (BNPP) but not various phosphomonoesters preserve LIF activity in the presence of the serine esterase inhibitor phenylmethylsulfonyl fluoride (PMSF). In this paper I demonstrate that guanosine 3′,5′‐cyclic monophosphoric acid (3′,5′‐cGMP), a naturally occurring phosphodiester, at concentrations in excess of 10−5M also protects LIF against PMSF inactivation. The effect seems specific for the diester bond, its position in the nucleotide, and the guanine base. The possibility that LIF may be a multifunctional or an allosteric enzyme regulated by 3′,5′‐cGMP is discussed.
Differences Between the Fc Receptors of Two Lymphocyte Subpopulations of Human Peripheral Blood
Authors: ARBEIT R. D. , HENKART P. A. , DICKLER H. B.
Published: August 2010

The Fc receptors of human peripheral blood lymphocytes bearing stable membrane Ig (B cells) and those bearing cytophilic membrane Ig (UL cells) were evaluated for binding avidity and interaction with human ‘Ia‐like’ alloantigens. Titration experiments showed that binding of soluble antigen–antibody complexes to UL cells was readily detected at low concentrations (5–10μg/ml), whereas high concentrations (400–800 μg/ml) were necessary to detect binding to most B lymphocytes. Binding at all concentrations was dependent on an intact Fc portion of the antibody molecule within the antigen–antibody complex. F(ab')2 fragments of antibodies against: human ‘Ia‐like’ antigens inhibited binding of complexed Ig to B cells but not UL cells. These differences are compatible with the possibility that the Fc receptors of the two cell populations are distinct molecular entities or, alternatively, are the same molecules and differ in quantity, distribution, or mobility on the surface of the two cell types.
Cross‐Reaction of a Minor Variant of the al Allotypic Specificity with Anti‐a2 Antibodies
Authors: ROLAND J. , BRÉZIN C , CAZENAVE P.‐A.
Published: August 2010

Certain samples of hare IgG can combine wish cross‐linked anti‐a2 antisera prepared in the a3/a3 rabbit. This cross‐reaction permitted the isolation, on hare IgG immunoadsorbent, of anti‐a2 cross‐reacting antibodies (anti‐a2(Lv) antibodies). The binding of labeled rabbit a2 IgG to insolubilized anti‐a2(Lv) antibodies is inhibited by a1 IgG, demonstrating a cross‐reactivity with a2. The percentage of a1 IgG cross‐reacting with anti‐a2 antiserum (a1(2) IgG) is about 0.5% of total a1 IgG. The a1(2) molecules represent another variant (or set of variants) of the a1 specificity. Demonstration of this variant of a1 IgG brings to seven the minimum number of described a1 variants, and its low concentration among a1 IgG (0.5%) is in favor of a larger number of variants of allotypic specificities. Arguments in favor of common ancestor genes for allotypy in lagomorphs are given.
Immunoglobulins in Families of Myeloma Patients
Authors: FESTEN J. J. M. , MARRINK J. , de WAARD‐KUIPER E. H. , MANDEMA E.
Published: August 2010

The serum immunoglobulin levels of 200 first‐degree relatives and 23 spouses of 32 patients with myelomatosis were compared with those of age‐ and sex‐matched control persons. First‐degree relatives of myeloma patients appeared to have higher serum levels of IgG (P < 0.05), IgA (P < 0.05), and IgM (P < 0.01) than their age‐ and sex‐matched controls. The spouses as a group did not differ from their controls in this respect. No statistically significant difference in the incidence of M‐components among family members (0.6%) and spouses (4.3%) was found compared with the incidence in the general population (0.9%). Myelomatosis as such appeared to be more frequent than in the general population (P < 0.05).
Depression of Human Neutrophil Motility by Influenza Virus In Vitro
Authors: RUUTU P. , VAHERI A. , KOSUNEN T. U.
Published: August 2010

After in vitro treatment of human peripheral neutrophils for 60 min at 37°C with purified influenza A virus, their random locomotion (no chemoattractant), chemokinesis (migration in the presence of a chemoattractant without a gradient), and chemotaxis were depressed, as determined by a modification of the Boyden method. The inhibition was accentuated by the presence of human serum devoid of antibodies to the virus. A strain of influenza B virus did not depress neutrophil motility at the same concentration and agglutinated the neutrophils at higher concentrations. Antiserum treatment partly abolished the inhibitory activity of the influenza virus. Inactivation of the virus infectivity with Tween 80 and ether did not change the ability of the virus to inhibit neutrophil motility. Bacterial neuraminidase did not inhibit neutrophil motility. Pretreatment of neutrophils with amantadine hydrochloride, which has been reported to block viral replication in its early stages, did not modify the depression of neutrophil motility by influenza A virus. The results give additional support to the suggested mechanism of depressed neutrophil function as a cause of bacterial superinfection after influenza.
In Vivo Responses of Alloreactive Lymphocytes Stimulated In Vitro
Authors: CORLEY R. B. , KINDRED B.
Published: August 2010

Populations of mouse lymphocytes enriched in specific alloreactive cells by priming in a mixed lymphocyte response (MLR) include cells which, when injected into congenic nude mice, enable them to make alloantibody after immunization. Helper cells for the priming H‐2 alloantigins (H‐2b or H‐2k) were enriched relative to helper tells for the other H‐2 type. Furthermore, the alloantibody responses of nude mice reconstituted with lymphocytes primed twice in vitro were virtually monospecific for the priming alloantigens. These studies suggest that lymphocytes that proliferate in MLR include lymphocytes capable of giving specific help for H‐2 antigens in vivo. Nude mice reconstituted with MLR‐primed lymphocytes, made less antibody to bacteriophage T4 and x than mice reconstituted with unprimed cells, and fewer mice responded. Priming of cells a second time in MLR further depleted the population of phage helper cells. Similar results were sometimes, but not always, obtained when testing reconstituted nude mice for their ability to make anti‐sheep erythrocyte (SRBC) responses. These results suggest that lymphocytes primed against H‐2b or H‐2k alloantigens do not have specificity for antigens of T4 or x. These alloreactive cells may also lack specificity for SRBC. However, the results do not allow a definitive conclusion to be drawn.
Specific Suppression of MLC and CML by Anti‐Idiotypic Antibodies in the Mouse
Authors: WIGHT E. , BINZ H.
Published: August 2010

Rabbit antisera directed against idiotypic determinants of alloreactive mouse CBA anti‐C57BL/6 T blasts were raised in the following manner: first, a rabbit serum directed against nonspecific CBA blasts cells was prepared by injecting CBA concanavalin A blasts three times at monthly intervals into a rabbit. Second, specific CBA anti‐C57BL/6 T lymphoblasts were induced in a mixed lymphocyte culture (MLC), were purified by gravity sedimentation through a fetal calf serum gradient, and. finally, were incubated with the anti‐blast serum from the first step. During this incubation, presumably all epitopes of the blast cell population were blocked by anti‐blast antibodies, except for the greatly amplified set of CBA anti‐C57BL/6 alloreactive idiotypes. The mixture was then Injected into fresh rabbits, which were boosted with similar mixtures after 3 and 6 weeks. Blood samples were removed 10 days after each injection. Such sera, when used together with complement, inhibited specifically the stimulation of CBA cells by C57BL/6 antigens in MLC and the CBA anti‐C57BL/6 killer cells.
Acute‐Phase Proteins or Tumour Markers: The Role of SAA, SAP, CRP and CEA as Indicators of Metastasis in a Broad Spectrum of Neoplastic Diseases
Authors: WEINSTEIN P. S. , SKINNER M. , SIPE J. D. , LOKICH J. J. , ZAMCHECK N. , COHEN A. S.
Published: August 2010

Two hundred and seventy‐seven patients with a broad spectrum of neoplastic diseases, including 10 classes of solid tumours and three classes of haematologic malignancies, were retrospectively surveyed, and from the same sample of plasma or serum their concentrations of serum amyloid A (SAA), serum amyloid P component (SAP), C‐reactive protein (CRP), and carcinoembryonic antigen (CEA) were measured. SAA levels varied from 105 ng/ml to 105,000 ng/ml, and mean SAA levels were higher in patients with metastatic tumours than in those with limited disease (P<0.001). Similarly, CRP levels varied from less than 8 μg/ml to 328 μg/ml and were significantly higher in the metastatic disease category. In contrast, SAP levels varied from 32 μg/ml to 120 μg/ml and showed no difference in patients with limited or metastatic disease, although an overall slight elevation was present. CEA levels were available in 150 patients and were significantly higher in patients with advanced lung or breast cancer than in patients with limited disease. The correlation between mean SAA and CRP levels was significant (r=0.74, P<0.001), suggesting that SAA originates as an acute‐phase protein rather than as a tumour cell product. However, the consistent elevation of SAA in all tumour types and the more marked elevation in metastatic disease may make its measurement useful in malignancy.
Glucocorticosteroids in Renal Transplantation
Authors: HAYRY P. , AHONEN J. , KOCK B. , EKLUND B. , KAUSTE A. , KOSKIMIES S. , VON WILLEBRAND E.
Published: August 2010

In a previous clinical trial we demonstrated that. by increasing the postoperative administration of methylprednisolone from 1.0 to 3.5 mg/kg/day. ihe onset of the first inflammatory rejection episode was significantly delayed and the size of the inflammation was reduced. The ‘high initial’ steroid treatment specifically depleted blast cells and macrophages from the in situ inflammatory infiltraie. In ihis trial we demonstrate that the ‘high initial’ glueocorticosteroid administration significantly improves 1‐year cadaver allograft survival from 44% to 68% (P = 0.00.3) without increasing the number of complications. Although the ‘high initial’ steroid administration only partially overcomes the impact of HLA‐AB incompatibility, it seems to overcome entirely the impact of absence of blood transfusions. The ‘high initial’ steroid administration also makes the first episodes of inflammation easier to overcome: less steroids are needed to counteract the first rejection, and, as a consequence, only 30% more steroids were used in the ‘high initial’ versus the ‘low intial’ steroid programme.
Quantification of the C3d Split Products of Human Complement by a Sensitive Enzyme Linked Immunosorbent Assay
Authors: MOLLNES T. E.
Published: August 2010

A double‐antibody biotin‐avidin enzyme‐linked immunosorbenl assay (ELISA) for quantification of the C3d split products is described. Polyethylene glycol MXJO was used to precipitate large C3 molecules, and the C3d‐containing supernatant was used in the assay. C3d was measured in ethylenediamineietraacetic acid plasma from 40 healthy blood donors, and the normal range wa.s defined. Twenty‐two patients were tested, and 12 of these had increased levels of C3d. No correlation was observed between total C3 and C3d in these patient;., There was a close correlation between C3d measured hy ihis method and by the double‐decker rocket immunoelectrophoresis method. The C3d ELISA method is very sensitive, easy lo perform, and lime‐saving and economical compared with most C3d methods already described. A procedure lo define the lower detection limit and examine the reliabiliiy of an ELISA method in general is discussed.
Myelopeptides—Bone Marrow Mediators with Immunostimulating and Endorphin‐Like Activity
Authors: PETROV R. V. , MIKHAILOVA A. A. , ZAKHAROVA L. A. , VASILENKO A. M. , KATLINSKY A. V.
Published: August 2010

Bone marrow cells, produce soluble mediators with structural and functional heterogeneity. They were found to stimulate antibody production at the peak of the immune response, owing to compounds of a peptide nature (M1 2000–1300). Active material was isolated by means of gel chromatography and electrophoresis. This material positively reacts with ninhydrin, and has maximum absorption close to 278 nm. Its antibody‐stimulating activity decreased or stopped completely after treatment with proteolytic enzymes. Apart from the immunostimulating activity, bone marrow mediators have opiate‐like activity. They have an analgetic effect, and interact with the opiate receptors of brain nerve cells. After a physicochemical and functional analysis, we concluded that bone marrow produces regulatory peptides that were previously unknown. We called them myelopeptides.
Biochemical Characterization of the T‐Cell Mitogen Derived from Mycoplasma arthritides.
Authors: KIRCHNER H. , BREHM G. , NICKLAS W. , BECK R. , HERBST F.
Published: August 2010

A biochemical procedure is described to purify the T‐cell mitogen in the supernatant of cultured Mycoplasma arthritidis organisms. The mitogenic material was bound on an affigel blue column. The eluate of this column was then acylated at 0°C for 1.5 h and subsequently chromatography on a Sepharose C1 6B and a Superose 12HR column were performed. SDS‐PAGE showed a major band at MW 26,000 and some minor bands at 50,000. With this material biological tests were performed, including induction of lymphoproliferation and interferon induction in murine spleen cell cultures. Purified Mycoplasma arthritidis supernatant (MAS) vigorously stimulated spleen cell cultures of A/J, CBA, C3H/He, and DBA/2 mice, whereas a low‐grade hut definitive response was observed in C57BL/6 spleen cells. Cultures of Balb/c nu/nu mice, in contrast to those of their euthymic littermates, were non‐reactive. When induction of interferon was tested, a marked response to purified MAS was observed in CBA and C3H/HeJ spleen cell cultures, whereas C57BL/6 spleen cells were non‐reactive.
The Terminal Complement Complex in Sera Deficient in the Eighth Component of Complement (C8)
Authors: MOLLNES T. E. , LEA T. , ROGDE S. , TEDESCO F.
Published: August 2010

The terminal complement complex (TCC) was quantified in sera from patients with a genetic deficiency of C8α‐γ or C8β The individual sera contained only trace amounts of TCC compared with a normal serum pool. The content of TCC increased after mixing the two sera, which was consistent with reconstitution of C8 activity. Only a moderate increase in TCC was obtained after zymosan activation of the individual sera, whereas activation of the mixture resulted in high amounts of TCC. C8 was demonstrated in the TCC of both deficient sera. These results may indicate that functional C8 is present in trace amounts despite the genetic deficiency, and that the terminal pathway may function to some extent although not enough to be detectable in less sensitive assays.
Connectivity and HIV‐1 Infection: Role of CD4+ T‐Cell Counts and HIV‐1 RNA Copy Number
Authors: Padierna‐Olivos L. , Moreno‐Altamirano M. M. B. , Sánchez‐Colón S. , Massó‐Rojas F. , Sánchez‐García F. J.
Published: August 2010

Following primary infection with human immundeficiency virus (HIV)‐1, antibodies against specific HIV‐1 epitopes are elicited. However, non‐HIV‐1 specific antibodies, including autoantibodies, also arise. In fact, it has been proposed that such autoantibodies have an important role in the pathogenesis of HIV‐1 infection. Because an imbalance in connectivity has been associated with autoimmune processes, we investigated the connectivity status of HIV‐1‐infected individuals. Moreover, we tested the possible role of viral load and CD4+ T‐cell counts, in connectivity, because these parameters appear to be important in the prognosis of HIV‐1 infection. Results show that indeed, there is an alteration in connectivity in these patients, both for immunoglobulin (Ig)G and IgM, which is an immune alteration not previously identified in HIV‐1 infection. In addition, our results show that viral load and CD4+ T‐cell counts are both equally important in defining the characteristic pattern of connectivity in HIV‐1‐infected individuals, and that neither is independently responsible for alterations in patient connectivity status.
Synchronous Deletion of Mtv‐Superantigen‐Reactive Thymocytes in the CD3medium/high CD4+CD8+ Subset
Authors: Sheard M. A. , Sharrow S. O. , Takahama Y.
Published: August 2010

Multiple model systems have demonstrated that negatively selected thymocytes can be deleted during the immature CD4+CD8+ CD3low stage after high affinity interaction of T‐cell receptors (TCRs) with antigen:major histocompatibility complex (MHC) complexes. Superantigens (SAGs) derived from endogenous mammary tumour viruses (Mtv) induce negative selection of Mtv‐SAG‐reactive thymocytes regardless of which peptide antigen is presented by MHC molecules. In this study, the timing of deletion of multiple subsets of Mtv‐SAG‐reactive CD4+CD8+ thymocytes was investigated by a 4 colour flow cytometry in SJL × CBA/J cross‐bred mice. Deletion of Vβ3+, Vβ5+, Vβ11+, and Vβ17+ Mtv‐SAG‐reactive thymocytes was found to occur synchronously in the most mature CD3medium and early CD3high subsets of CD4+CD8+ thymocytes, in contrast with reports showing that the deletion of Mtv‐SAG‐reactive thymocytes can occur at different stages in particular model systems.
Effects of Interleukin‐12 in the Long‐term Protection Conferred by a Mycobacterium avium Subunit Vaccine
Authors: Silva R. A. , Pais T. F. , Appelberg R.
Published: August 2010

The effects of the addition of recombinant interleukin (IL)‐12 to a mycobacterial subunit vaccine were analyzed in terms of the longevity of the protective immunity generated. BALB/c mice were immunized with culture filtrate proteins from Mycobacterium avium with dimethyl‐dioctadecilammonium bromide (DDA) as an adjuvant. This subunit vaccine induced protection against a challenge by M. avium which lasted for at least 6 months while waning with time until 1 year postvaccination. Whereas the addition of IL‐12 enhanced the initial protective efficacy of this subunit vaccine during the first 6 months, it accelerated the loss of protective efficacy observed at 1 year postvaccination. These data confirm the adjuvant properties of IL‐12 in vaccines against mycobacteria and raise the possibility of late counter‐protective untoward effects.
Cytokines Involved in Toxoplasmic encephalitis
Authors: Sarciron M. E. , Gherardi A.
Published: August 2010

Reactivation of cerebral toxoplasmosis occurs in approximately 30% of acquired immune deficiency syndrome (AIDS) patients who are seropositive for Toxoplasma gondii and a change in the levels of cytokines during this relapse is observed. Several cytokines are able to initiate meningeal inflammation and may play a role in the immunopathogenesis of the disease. The induction of a type 1 inflammatory cytokine response is a key event in the initiation of immunity to T. gondii. Interleukin (IL)‐10 production in infected brain facilitates the persistence of parasites by down‐regulating the intracerebral immune response. The in vivo and in vitro models are very numerous and this may explain the heterogeneity of the results. The role of gamma interferon is important because it is the principal mediator inducing a host resistance against T. gondii. Several cytokines stimulating or decreasing interferon (IFN)‐γ levels are reported. The particular case of AIDS patients whose humoral response is altered, is studied.
Alterations during Positive Selection in the Thymus of nackt CD4‐Deficient Mice
Authors: Nepomnaschy I. , Lombardi G. , Bekinschtein P. , Berguer P. , Francisco V. , De Almeida J. , Buggiano V. , Pasqualini C.D. , Piazzon I.
Published: August 2010

The T‐cell repertoire is shaped by the positive and negative selection of immature CD4+ CD8+ double positive (DP) thymocytes. Positive selection of DP T cells to the CD4+ CD8− and CD4− CD8+ simple positive (SP) lineages is a multistep process which involves cellular interactions between thymocytes and stromal cells. Mutant nackt (nkt/nkt) mice have been shown to have a deficiency in the CD4+ CD8− T‐cell subset both in the thymus and in the periphery. The present report suggests that nkt/nkt mice present alterations in early steps of positive selection because they show decreases in the percentages of CD69+ and CD5+ cells within the DP subset. Experiments involving bone marrow transfer and thymic chimeras demonstrate that the thymic epithelium of nkt/nkt mice is involved in the alterations registered during positive selection and dictates the ultimate fate of CD4+ SP cells.
Characterization of Proteoglycans and Glycosaminoglycans in Splenic AA Amyloid Induced in Mink
Authors: Wien T. N. , Omtvedt L. A. , Landsverk T. , Husby G.
Published: August 2010

Amyloidosis of the protein AA type is readily induced in mink using repeated injections of bacterial lipopolysaccharide (LPS). We have characterized splenic proteoglycans/glycosaminoglycans (PGs/GAGs) in mink during amyloidogenesis. Moderate to rich amounts of amyloid exhibiting green birefringence was demonstrated by polarization microscopy of the splenic section stained with Congo red in seven out of eight minks after 10 weeks of LPS‐treatment, and a significant increase in the total amount of PGs and GAGs in AA amyloid spleens was observed (two to eight times that in unstimulated animals). Intact PGs as well as free GAGs were extracted, and heparan sulfate (HS) was the most abundant GAG in the amyloid as well as in the control spleens. The GAGs showing the most pronounced increase in the amyloid spleens was of the chondroitin sulfate/dermatan sulfate (CS/DS) type and these were extracted in the form of free GAG chains. We conclude that there is a selective enrichment of PGs/GAGs in extracted splenic amyloid in the mink, which confirms to previous observations in human amyloid as well as in other animal species, supporting their pathogenic significance in the formation of AA amyloid.
Molecular Weight Dependency on the Production of the TNF Stimulated by Fractions of rye (1→3),(1→4)‐β‐d‐Glucan
Authors: Roubroeks J. P. , Skjåk‐Bræk G. , Ryan L. , Christensen B. E.
Published: August 2010

Mixed‐linkage (1→3),(1→4)‐β‐d‐glucan with a weight average molecular weight varying between 79 800 and 13 900 was purified from rye. These fractions were used for stimulation of human monocytes to produce tumour necrosis factor (TNF). A mixed‐linkage β‐glucan with a weight average molecular weight of 18 900 was found to be the most potent immunostimulator.
Crosslinking of CD30 on Activated Human Th Clones Enhances Their Cytokine Production and Downregulates the CD30 Expression
Authors: Bengtsson Å. , Scheynius A. , Avila‐Cariño J.
Published: August 2010

Signalling through CD30 has been shown to mediate pleiotropic effects, depending on the type of target cell. In the present study, we have used the agonistic anti‐CD30 monoclonal antibodies (MoAb) M44 to study phenotypic changes in human T‐cell clones of Th1 and Th2 type. Alterations in the surface expression of CD30, CD28 and CD40L following CD30 stimulation were analyzed after 24 h, and the cytokine production after CD30 crosslinking was measured at 48 h. We observed a clear reduction of surface expression of CD30 after treatment with the M44 MoAb. Our results also indicate that CD28 is significantly down modulated in the Th2 clones after CD30 crosslinking (P < 0.05, n = 5) whereas no apparent alteration was observed in the expression of CD40L. When the concentration of cytokines was measured in the supernatants after CD30 stimulation, elevated levels of interleukin (IL)‐4 and IL‐5 were observed in the Th2 clones, and elevated levels of interferon (IFN)‐γ in the Th1 clones. The enhanced cytokine production after CD30 crosslinking supports the presumption of CD30 functions as a positive regulator in activated T cells.
Clinical Relevance of Cytokine Production in HIV‐1 Infection in Children on Antiretroviral Therapy
Authors: Resino S. , Bellón J. Ma , Sánchez‐Ramón S. , Gurbindo D. , Muñóz‐Fernandez Ma A.
Published: August 2010

In order to investigate the correlation among cytokine production and antiretroviral therapy (ART), viral load, CD4+ and CD8+ T lymphocytes, 55 human immunodeficiency virus (HIV)‐1‐infected children on ART or not, and 16 uninfected controls were studied. Peripheral blood mononuclear cells (PBMCs) of HIV‐1‐infected children and controls were cultured and spontaneous and mitogen‐stimulated cytokines production was quantified in the supernatants. Viral load was quantified using standard molecular assay. CD4 and CD8 T‐lymphocyte counts were determined by flow cytometry. Cytokine production by mitogen‐stimulated PBMCs showed different profiles in HIV‐1 children whether treated or not. The tumour necrosis factor (TNF)‐α production was higher and the interleukin (IL)‐10 production was lower in the HIV‐1‐untreated group than in the HIV‐1‐treated children and controls. The IL‐2 production was reduced and the RANTES production was higher in both HIV‐1 groups compared with the controls. The interferon (IFN)‐γ and the IL‐5 production was significantly reduced in the HIV‐1‐treated children compared to the controls. Interestingly, the analysis of the correlation of HIV‐1 phenotype with cytokine production indicated an increased RANTES production in relation to nonsyncytium‐inducing viral phenotype with slow/low replication profile, whereas decreased IL‐10 levels was associated to syncytium‐inducing (SI) strains and rapid/high replication. Our findings suggest that AVT changes on the cytokine and chemokine production play an important role in the HIV pathogenesis.
IL‐21 Modulates CD4+ CD25+ Regulatory T‐Cell Homeostasis in Experimental Autoimmune Encephalomyelitis
Authors: Piao W.‐H. , Jee Y. H. , Liu R. L. , Coons S. W. , Kala M. , Collins M. , Young D. A. , Campagnolo D. I. , Vollmer T. L. , Bai X.‐F. , La Cava A. , Shi F.‐D.
Published: August 2010

Abstract The homeostasis of CD4 + CD25 +  regulatory T cells (Tregs) depends on the cytokine interleukin (IL)‐2. As IL‐21 shares sequence homology with IL‐2 and the IL‐21 receptors contain a γ‐chain common to IL‐2, we hypothesized that IL‐21 could also affect the homeostasis of Tregs. We tested this hypothesis in experimental autoimmune encephalomyelitis (EAE), an animal model of relapsing‐remitting human multiple sclerosis. We show that blockade of IL‐21 in SJL/J mice before and after the induction of EAE enhances the influx of inflammatory cells into the central nervous system (CNS). The blockade of IL‐21 leads to proliferation of proteolipid peptide (PLP139‐151)‐autoreactive CD4 +  T cells, which are capable to cause severe EAE in adoptively transferred recipient mice. Conversely, Tregs from mice where IL‐21 was blocked, lose their capacity to prevent EAE induced PLP139‐151‐reactive T cells. Notably, direct effects of IL‐21 on Tregs are confirmed by studies of blockade of IL‐21 in mice expressing a green fluorescent protein ‘knocked’ into a Foxp3 allele, in which a reduction of the number of Tregs and a downregulation of their frequency and expression of Foxp3 are observed. These data suggest a role of the IL‐21/IL‐21R axis in the homeostasis of Tregs in CNS autoimmunity.
Enumeration of Haemagglutinin‐specific CD8+ T Cells after Influenza Vaccination Using MHC Class I Peptide Tetramers
Authors: Krnic E. Kosor , Gagro A. , Drazenovic V. , Kuzman I. , Jeren T. , Cecuk‐Jelicic E. , Kerhin‐Brkljacic V. , Gjenero‐Margan I. , Kaic B. , Rakusic S. , Sabioncello A. , Markotic A. , Rabatic S. , Mlinaric‐Galinovic G. , Dekaris D.
Published: August 2010

With emergence of MHC class I tetramers loaded with CD8+ T‐cell viral epitopes, it is possible to study virus‐specific CD8 cells in humans during infection and after vaccination. MHC class I tetramers was used to detect the frequency of haemagglutinin (HA)‐specific T cells in 26 healthy influenza‐vaccinated humans. Peripheral blood was collected before, and 7, 14 and 28 days after vaccination. Four‐colour flow cytometry was used for monitoring of vaccine induced T‐cell response. In 15 donors, two‐ to fivefold increase in frequency of HA‐specific T cells was observed 7 days after vaccination. In addition, in 12 of these donors, this increase was accompanied with fourfold increase of H1N1 antibody titre. The increase in frequency of HA‐specific CD8+/IFN‐γ+ cells was low and peaked 28 days after vaccination in three of the six donors tested. Frequencies of HA‐specific CD8+ T cells and antibody titre returned to prevaccination values 1 year after vaccination. Subunit influenza vaccines have the ability to induce HA‐specific CD8+ cells. As the immune response to this vaccine decreased significantly after 1 year, our results confirm the importance of annual immunization for adequate protection.
Effects of Single Administration of Morphine on G‐protein mRNA Level in the Presence and Absence of Inflammation in the Rat Spinal Cord
Authors: Askari N. , Mahboudi F. , Haeri‐Rohani A. , Kazemi B. , Sarrami R. , Edalat R. , Ahmadiani A.
Published: August 2010

AbstractAntinociceptive potency of opioids is greater against various noxious stimuli in animals with peripheral inflammation. Opioid agonists stimulate activation of G‐protein‐coupled receptor. Changes in the resting levels of G‐protein subtypes could have an effect on intracellular signalling pathways. The present study was designed to investigate the effects of analgesic morphine treatment on the level G‐protein subunits mRNA in the presence and absence of inflammation. Our results showed that the carrageenan administration increased G‐protein subunits. Administration of analgesic dose of morphine alone and in the presence of inflammation induced different alterations in the levels of G‐protein mRNA. Taken together, the results obtained using real time RT‐PCR suggested that G‐protein genes expression levels following the acute administration of morphine between animals with and without inflammation could influence, at least in part, analgesic responsiveness.
IL‐17 Eliminates the Therapeutic Effects of Myelin Basic Protein‐Induced Nasal Tolerance in Experimental Autoimmune Encephalomyelitis by Activating IL‐6
Authors: Wang G.‐Y. , Sun B. , Kong Q.‐F. , Zhang Y. , Li R. , Wang J.‐H. , Wang D.‐D. , Lv G. X. , Li H.‐L.
Published: August 2010

Interleukin (IL)‐17 is a proinflammatory cytokine primarily secreted by Th17 cells, which are a CD4+ T‐cell subset. Th17 cells and IL‐17 are important in the pathogenesis of multiple sclerosis and in its established animal model, experimental autoimmune encephalomyelitis (EAE). However, it is unclear whether IL‐17 contributes to EAE immune tolerance. We used the myelin basic protein (MBP) peptide MBP 68–86 to induce nasal tolerance to EAE, and simultaneously interfered with the tolerance by treatment with different doses of IL‐17. We found that IL‐17 dramatically interfered with MBP 68–86‐induced immune tolerance. IL‐17 administration increased IL‐6 release, skewing T cell differentiation towards Th17 cells and decreasing the number of Treg cells. This led to an imbalance between Treg cells and Th17 cells and spurred the development of EAE.
Molecular mechanics studies on dipeptide models of diphenylalanine and its derivatives
Authors: RAO SHASHIDHAR N. , CHAN MING FAI , PROFETA SALVATORE S. , BALAJI V.N.
Published: August 2010

As a part of our studies on the structure and conformations of peptidomimetics, we present conformational energy calculations on model peptides with (a) diphenyl alanine and its tricyclic derivatives and (b) triphenyl alanine residues using molecular mechanics and conformational analysis methods. The energies are calculated as a function of the backbone torsions (φ and ψ), and the results are presented in terms of isoenergy contours in the φ‐ψ space. The low‐energy models adopt conformations characteristic of a variety of regular structures such as the α‐helix, γ‐turn and polyproline‐II‐type three‐ and four‐fold helices. The conformational preferences in the model peptides with diphenyl alanine and its tricyclic derivatives are sensitive to the side‐chain torsion, with some similarities to the corresponding preferences of l‐Ala dipeptide. The energy profile of the model peptide with triphenyl alanine is similar to that of the model peptide with Tle (tert‐leucine) residue. The results of our studies have implications in the design of conformationally constrained peptidomimetics with structures in the β‐ and α‐helical regions.
Solution structure of synthetic peptide inhibitor and substrate of cAMP‐dependent protein kinase. A study by 2D 1H NMR and molecular dynamics
Authors: PADILLA ANDRÉ , HAUER JENNIFER A. , TSIGELNY IGOR , PARELLO JOSEPH , TAYLOR SUSAN S.
Published: August 2010

Peptides derived from the inhibitor of cAMP‐dependent protein kinase, PKI, have been studied by 2D 1H NMR techniques. These include the inhibitor PKI(6‐22), the substrate [Ala20‐Ser21] PKI(5‐24), and a phosphorylated form of the latter [Ala20‐Ser21P] PKI(5‐24). A homologous fold was found in the three peptides which consisted of an N‐terminal segment in helical conformation to residue 13 and a C‐terminal segment poorly defined conformationally. A parallel study was carried out by molecular dynamics (MD) for the inhibitor peptide PKI (5‐24). The N‐terminal helix, as observed in the crystal structure of the catalytic subunit‐PKI(5‐24) complex, was conserved in the MD simulations with the enzyme‐free inhibitor. Similarly the Gly14‐Gly17 turn was apparent in all MD structures, whereas the C‐terminal region, residues 18‐24, was directed towards the N‐terminal helix in contrast to the extended conformation of this segment pointing away from the N‐terminal helix in the crystal structure. This is primarily due to ionic interaction between Asp9 and Arg15. Indeed, a detailed analysis of the NOE contacts by NOESY at low temperature (2°C) shows the occurrence of pH‐dependent contacts with Phe10. We conclude that the binding of short inhibitors, such as PKI (5‐24), to the enzyme involves a conformational rearrangement of the C‐terminal region. The substrate [Ala20‐Ser21] PKI (5‐24) and the product [Ala20‐Ser21P] PKI(5‐24), give very similar structures with local rearrangements involving some of the side chains. © Munksgaard 1997.
Synthesis and activity of partial retro‐inverso analogs of the antimetastatic laminin‐derived peptide, YIGSR‐NH2
Authors: ZHAO MING , KLEINMAN HYNDA K. , MOKOTOFF MICHAEL
Published: August 2010

This paper describes the synthesis and biological evaluation of six partial retro‐inverso peptidomimetic analogs of YIGSR‐NH2, a synthetic peptide from the β1 chain of laminin, which has antimetastatic activity. The intent was to improve the antimetastatic potency of YIGSR‐NH2 by limiting the in vivo enzymatic degradation through the incorporation of fraudulent peptide bonds. We have prepared the following retro‐inverso peptides, Tyr‐Ile‐Gly‐Ser‐gArg‐CHO (1), Tyr‐gIle‐mGly‐Ser‐Arg‐NH2 (2), Tyr‐glle‐mGly‐Ser‐gArg‐CHO (3), gTyr‐D‐rIle‐mGly‐Ser‐Arg‐NH2 (4), Tyr‐Ile‐Gly‐gSer‐o‐rArg‐CHO (5) and Tyr‐glle‐rGly‐D‐rSer‐D‐rArg‐CHO (6). In vitro assays for B16F10 melanoma cell adhesion showed no significant activity for these six peptides. Peptides 1‐3, 5 and 6 were further tested, in vivo, for their ability to inhibit tumor metastases to the lung in mice injected in the tail vein with B16F10 melanoma cells. All five of the retro‐inverso peptides tested showed statistically significant inhibition of metastasis, but the most active peptides were 5 and 6, which showed 57 and 69% inhibition of metastasis, respectively. © Munksgaard 1997.
Nuclear magnetic resonance studies of the C‐terminal human growth hormone fragment I179–C182–[SS]‐C189‐P191 and the related trisulfide peptide I179–C182‐[SSS]‐C189–P
Authors: STRANDBERG ERIK , KORDEL JOHAN , LUNDIN RONNY , WEHLER THOMAS , WIDMALM GÖRAN
Published: August 2010

The synthetic C‐terminal hGH fragment I179‐C182‐[SS]‐C189‐P191 and the related trisulfide peptide I179‐C182‐[SSS]‐C189‐P191 have been studied using homonuclear 1H‐NMR methods and distance geometry calculations. The 1H‐NMR spectra of both the disulfide (diS) and the trisulfide (triS) were completely assigned. Amide proton exchange rates, NOEs and the temperature dependence of the NH chemical shifts indicate a hydrogen bond in triS between Val 185 and Ser 188 stabilizing a turn in this region. 3JH, H coupling constants and NOEs were measured and used as input for distance geometry calculations. For triS two families of structures with averaged pairwise backbone root mean square deviations for Cys 182‐Cys 189 of 1.3–1.5 Å were found, only one of which is compatible with experimental data. For diS only one family of structures was found, but with such a low structural definition (backbone rmsd >2Å) that no interpretation into a consensus structure is useful. The generated structures were compared to the crystal structure of the terminal loop in hGH. complexed to its binding proteins. The resemblance was low between the solution structures of the tridecapeptides and the terminal hGH loop. © Munksgaard 1997.
Sulfonated analogues of cyclolinopeptide A Synthesis, immunosuppressive activity and CD studies
Authors: CEBRAT MAREK , LISOWSKI MAREK , SIEMION IGNACY Z. , ZIMECKI MICHAL , WIECZOREK ZBIGNIEW
Published: August 2010

Linear and cyclic analogues of cyclolinopeptide A (CLA) in which one or both phenylalanine residues in fragment Pro6‐Pro7‐Phe8‐Phe9 were substituted by their sulfonated derivatives have been synthesized by SPPS method and cyclization with the BOP reagent. The peptides were examined for their immunosuppressive activity in the humoral and cellular immune response by PFC and DTH tests. All of the analogues retain some immunosuppressive activity of native CLA. Their CD spectra confirm that the optical activity of aromatic residues in CLA depends on their position in the peptide chain. Only the residue in position 8 seems to be optically active. CD spectrum of the cyclic analogue modified in position 9 is very similar to that of native CLA which correlates with its high biological activity. The chiroptical properties of the p‐sulfonated Phe‐residue are established. © Munksgaard 1997.
Synthesis and biological activity of novel backbone‐bicyclic Substance‐P analogs containing lactam and disulfide bridges
Authors: BITAN GAL , SUKHOTINSKY INNA , MASHRIKI YAFHA , HANANI MENACHEM , SELINGER ZVI , GILON CHAIM
Published: August 2010

A biased library of 60 novel backbone‐bicyclic Substance P analogs was prepared by the simultaneous multiple peptide synthesis method. The peptides, containing both a lactam and a disulfide ring, were synthesized by combined Boc and Fmoc chemistries, and were cyclized on the resin. Cleavage of the S‐benzyl group and oxidation of the sulfhydryl groups was enabled by adaptation of the diphenylsulfoxide‐trichloromethylsilane method to solid‐phase synthesis. The peptides were screened for NK‐1 and NK‐3 activity, and were found to be weak agonists. © Munksgaard 1997.
Conformational dynamics and kinetics of peptide antagonist interactions with interleukin‐1 receptor. Fluorescence studies using the NBD‐labelled peptide AF12415
Authors: COWLEY DAVID J. , SCHULZE ANDREAS J.
Published: August 2010

Interleukin‐1 plays a key role in the inflammatory response provoked by various disease states and inhibition of its action can bring therapeutic benefits. Steady‐state and time‐resolved studies of the intrinsic tryptophan fluorescence of the free soluble Type I form of interleukin‐1 receptor (IL‐1R) reveal that the rotational motions of the three major domains are strongly associated. Bound peptide antagonists are buried in hydrophobic regions, but a flexible association permits access to species from the aqueous phase. Ligand binding does not lead to rigidification of the receptor structure. The kinetics and mechanism of complex formation and dissociation, involving IL‐1R with receptor antagonist protein (IL‐1ra) and with peptides AF11733 (15 aa) and AF10961 (21 aa) were determined with the aid of peptide AF12415 (15 aa) labeled at its N‐terminus by the NBD fluorophore, which exhibits a five‐fold increase in emission intensity at 540 nm on binding of the peptide to IL‐1R. The magnitude of the ON rate constant, typically 1 × 106 M−1 s−1, implies the existence of an intermediate ‘encounter complex’ involving interactions of low specificity. Readjustments of the initial encounter complex leads to a final complex where very specific interactions dominate. The first‐order rate constant for this latter process is the most sensitive indicator of the true peptide affinity for the receptor binding site, and thus provides a better criterion than the apparent OFF rate (typically 2 × 10−3 s−1) for discrimination of peptide antagonists. © Munksgaard 1997.
Inhibition of bovine trypsin by the phosphorylated N‐terminal part β(1–105) of β‐casein
Authors: BOUHALLAB S. , SAPIN B. , MOLLÉ D. , HENRY G. , LÉONIL J.
Published: August 2010

The sensitivities of the R25‐I26 bond on bovine β‐casein and on its N‐terminal fragment β(1–105) to trypsin digestion were compared by monitoring the liberation of the β(1–25) product. It was shown that this peptide bond was poorly and slowly hydrolysed on β(1–105), while it is highly susceptible to trypsin attack when whole protein is used as substrate. The marked resistance of β(1–105) is linked to its inhibitory effect on trypsin activity (apparent K′i= 1.2 × 10−6, M), as demonstrated by using a related chromogenic substrate. Indeed, a preincubation step of trypsin with β(1–105) leads to a more pronounced inhibitory effect. The progress curves obtained with and without preincubation show that β(1–105) acts as a slow binding inhibitor on trypsin activity. These findings promise further insight into the action and the regulation of proteolytic enzymes. © Munksgaard 1997.
Crystal structures of heterochiral peptides
Authors: NAGARAJAN V. , PATTABHI VASANTHA , JOHNSON A. , BOBDE V. , DURANI S.
Published: August 2010

Crystal structure of a heterochiral peptide. viz. Boc‐Val1‐d‐Ala2‐Leu3‐Ala4‐OMe with a d chiral residue in the second position of a sequence, has been determined [a= 40.44(1), b= 4.887(5), c= 15.381(5) Å, β= 109.6(1)°, space group C2, Z= 4, R= 0.11]. The peptide is in a parallel β‐sheet structure terminated by a distinct local bend. The structure is stabilised by N–H⋯O as well as Cα–H⋯O hydrogen bonds. The contiguous Cα‐H⋯O hydrogen bond observed in this structure is an unique observation. © Munksgaard 1991.
Circular dichroism studies of human big‐endothelin‐1 (Big ET‐1)
Authors: WALLACE B.A. , CORDER ROGER
Published: August 2010

The circular dichroism (CD) spectra of human endothelin (ET‐1) and its precursor (Big ET‐1) have been compared in order to provide information on the secondary structure of Big ET‐1. It appears that the secondary structures of the common parts of the two molecules are very similar and that the additional C‐terminal residues in Big ET‐1 may contain both helical and sheet components, information which may be of use in modeling studies of the Big ET‐1 structure.

In studies of the pH dependence of the conformation of Big ET‐1, it was found that Big ET‐1 adopts similar structures at pH 6.0 and 7.0, but has a subtly different conformation at pH 8.0 that may result in a reduced susceptibility to proteolysis at this pH. This difference may be in the conformation of a turn‐type structure, producing a less accessible peptide bond in the molecule at the site of cleavage. © Munksgaard 1997.