bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of a Vimentin‐Like Function Associated Molecule (FAM) on Rat NK Cells: Evidence for Receptor Function
Authors: EVANS D. L. , HARRIS D. T. , LEARY J. H. , JOHN A. L. ST , JASO‐FRTEDMANN L. 
Published: July 2006

Monoclonal antibody (MoAb) 5C6 specifically binds to fish, rat and human NK cells and inhibits cytotoxicity. The molecule recognized by this MoAb is a 50–53–kDa membrane protein on rat leukaemic NK (CRC) cells. In the present study, we have obtained a partial internal amino acid sequence from a purified 42‐kDa fragment of the CRC‐function associated molecule (FAM). Three tryptic peptide fragments were sequenccd and each showed homology to intermediate filament vimentin sequences as deduced from (GenBank) mouse cDNA sequences. Amino acid composition analysis indicated that similar to cytoskeletal vimentin, the FAM contained a high percentage of non‐polar amino acids. To further assess the similarities between this protein and vimentin., two commercially available anti‐vimentin MoAbsand one anti‐vimentin polyclonal antibody were tested for binding and inhibition of NK cytotoxicity. All anti‐vimentin MoAbs inhibited killing by rat NWNA cells of appropriate targets. Anti‐vimentin MoAb 13.2 bound to 41% of NWNA cells compared with approximately 58% binding for MoAb 5C6. Capping and sequential binding experiments showed that MoAb 5C6 effectively removed, from CRC‐cell membranes, the protein recognized by MoAb V9. Sequential addition of these two MoAbs (MoAb 13.2 followed by MoAb V9) to CRC cells did not produce competitive binding.Biochemical and Western blot analysis of the vimentin‐like protein obtained from CRC cells indicated that this protein has a molecular weight of 48–50 kDa, with an isoelectric point of pH 6.1–6.3. This protein is cross‐reactive by Western blot analysis with anti‐vimentin and anti‐intermediate filament (IFA) antigen MoAbs but not with anti‐desmin or anti‐actin M oAbs. The molecular weight heterogeneity (43 versus 48 50 k Da) of the CRC protein was also examined. Western blot analysis of the CRC extract after different in vitro incubation times at 37°C and 4°C demonstrated that the 50 53–kDa ‘native’ protein degraded to a 42‐kDa protein by 24 and 48 h respectively. This degradation was inhibitable by 10 mm EGTA.Evidence is presented which indicates that a vimentin‐like protein on transformed rat NK cells may be an antigen binding receptor which initiates target cell lysis.
Binding of Leukaemic Blasts to Various Subpopulations of Lymphokine‐Activated Killer Cells
Authors: PALUCKA A. K. , PORWIT A. , REIZENSTEIN P. 
Published: July 2006

Conjugate formation by natural killer (NK)‐resistant and N K‐sensitive leukaemic cell lines with fresh and IL‐2‐stimulated (lymphokine‐activated killer, LAK) peripheral blood lymphocytes (PBL) was studied by a flow cytofluorometry method with double staining, A significant difference in binding of NK‐resistant T‐cell lymphoma (HuT 78) and NK‐sensitive myeloid (K562) blasts to fresh PBL was observed (P<0.01). Activation of lymphocytes with IL‐2 resulted in a significant increase of binding and killing of both K562 and HuT 78. However, in the case of blasts from NK‐resistant cell line Daudi a similar conjugate formation with fresh PBL and LAK effectors was observed, despite a significant increase in killing. Various subpopulalions of LAK effectors (CD3, CD16 and CD56 positive) displayed similar binding activity towards myeloid (K562) and lymphoid (Raji) blasts, which shows that conjugate formation occurs not only with NK‐cell‐derived. but also with T‐cell‐derived LAK cells. The blocking of CD71 antigen (transferrin receptor) on K562 blasts inhibited binding of cytotoxic lymphocytes, which was mostly due to the blocking of binding of CD56+ subpopulation.Our results indicate that the resistance of leukaemic blasts to cell‐mediated cytotoxicity may depend on different (and probably several) steps of this process.
Characterization of a Tryptase mRNA Expressed in the Human Basophil Cell Line KU812
Authors: BLOM T. , HELLMAN L. 
Published: July 2006

The expression of a tryptic serine protease was detected in the cell line KU812 by Northern blot analysis with an oligonucleotide probe directed against a conserved region present in all of the five presently cloned human mast cell tryptases. PCR primers designed for the amplification of a nearly full‐length copy of tryptase mRNAs were used to study the identity of the KU812 tryptase. Ten clones were characterized and all were found to be identical to one of the tryptases previously cloned from a human skin cDNA library. This tryptase has been thought to originate from mast cells of the skin.Two possible explanations may account for the observed identity between the presumed mast cell tryptase and the KU812 tryptase. Firstly, it is possible that the KU812 tryptase is a basophil‐specific tryptase which has previously been cloned from a human skin cDNA library containing low levels of cDNA copies derived from basophils in the starting material. Secondly, the KU812 cell line, and possibly normal basophils, express a tryptase which is identical to one of the tryptases expressed in normal skin mast cells. We cannot at present rule out any of the two possibilities, but we favour the second explanation as being the most likely.
Preferential Vδ1 Expression among TcR γ/δ ‐Bearing T Cells in Human Oral Epithelium
Authors: PEPIN L. F. , ROGER T. , MORISSET J. , SEMAN M. 
Published: July 2006

The oral cavity is a septic area colonized by various bacterial species, and the oral mucosa is frequently submitted to microtraumas. Several mechanisms are implicated in the defence of the oral tissue, but little is known concerning the eventual presence and role of γ/δ T cells at this site.Samples of healthy keratinized oral mucosa were examined with immunochemica! techniques using anti‐CD3, CD4, CD8, CD22, TcRδ1, Vδl and Vδ2 monoclonal antibodies. Whatever the site examined. γ/δ T cells represent at most 2% of the T‐cell population, a value similar to that found in other tissues. In the connective tissue, under the basement membrane, Vδ2+γ/δ T cells are predominant whereas the epithelium mostly contains Vδ+γ/δ T cells. The significance of this preferential Vδ1 intraepithelial presence is discussed.
Recombinant Human Interleukin‐8 Restores Function in Neutrophils from Patients with Myelodysplastic Syndromes Without Stimulating Myeloid Progenitor Cells
Authors: ZWIERZINA H. , HOLZINGER I. , GAGGL S. , WOLF H. , SCHÖLLENBERGER S. , LAM C. , BAMMER T. , GEISSLER D. , LINDLEY I. 
Published: July 2006

Prognosis in myelodysplastic syndrome (MDS) is not only correlated closely with blast cell count in bone marrow and chromosomal abnormalities but also correlated with decreased leucocyte count and function leading to acquisition of lethal infections. Recently, clinical trials in MDS have focused on the application of haemopoietic growth factors such as G‐CSF or GM‐CSF, which have proven to increase neutrophil count and function. However, these cytokines carry the risk of stimulating the malignant clone, particularly in patients with increased blast cell count. Therefore, investigation of cytokines which are able to stimulate neutrophil function without the potential risk of stimulating haemopoietic progenitor cells may be relevant for MDS.As the stimulatory effect of interleukin‐8 on neutrophil function is well known, we investigated whether recombinant human IL‐8 is also able to improve the function of neutrophils gained from patients with MDS. Using three different techniques—the E. coli killing assay (8 patients), the production of reactive oxygen as determined by cytochrome c reduction (7 patients) and chemiluminescence (8 patients)—a significant stimulation of neutrophil function at a concentration of 10 nM IL‐8 was found in all test systems. No correlation with FAB classification was evident. On the other hand, IL‐8 only mildly stimulated growth of myeloid progenitor cells in bone marrow culture of healthy individuals and MDS patients. This minimal stimulation was blocked by a neutralizing antibody directed against GM‐CSF, suggesting an indirect effect of IL‐8 via secondary GM‐CSF release.Thus, IL‐8 is able in vitro to repair the functional abnormalities of neutrophils from patients with MDS but has only a marginal influence on myeloid progenitor cells.
Serum Amyloid‐P Component of the Armenian Hamster: Gene Structure and Comparison with Structure and Expression of the SAP Gene from Syrian Hamster
Authors: RUDNICK C. M , DOWTON S. B. 
Published: July 2006

Serum amyloid P(SAP), a phylogenetically conserved pentraxin, is an integral component of all amyloid deposits. Regulation of expression of SAP gene expression is quite different in two related hamster species. In Syrian hamsters, the resting serum levels of SAP are determined by gender, and the direction of alteration following inflammation is divergent. In Armenian hamsters, SAP is not a prominent acute‐phase reactant and there is no gender dimorphism of expression.The structure and expression of the SAP gene of the Armenian hamsters was investigated by isolation of genomic clones, nucleotide sequence analysis, and RNA studies. The gene structure of Armenian hamster SAP is similar to the genes of all other pentraxins studied. While the upstream regions of the SAP genes of Syrian and Armenian hamsters are quite similar, important differences in potential enhancer sites have been recognized by comparing the corresponding sequences of SAP genes from both species. Little alteration in hepatic levels of transcripts encoding SAP or CRP, the other pentraxin, were noted following administration of lipopolysaccharide to Armenian hamsters. This relative lack of response occurred despite a marked acute phase reaction documented for serum amyloid A mRNA levels.
B Cells Carrying Surrogate Receptors in their Membranes Process and Present Antigen to Specific Murine T Cells
Authors: GONTIJO C. M. , MÖLLER G. 
Published: July 2006

A palmitate‐conjugate derivative of ovalbumin which can be inserted into the membrane of B cells has been prepared. The ability of these cells to act as antigen‐presenting cells for specific T lymphocytes obtained from immunized mice was tested. It was found that the conjugates were more efficiently processed and presented than the naive form of the antigen.Palmitate‐conjugated antibodies specific to ovalbumin were also inserted into the cell membrane of normal B lymphocytes. These cells were pulsed with the antigen and tested as antigen‐presenting cells for T cells obtained from immunized mice. The antibody‐decorated B cells presented ovalbumin more efficiently than non‐decorated controls.Whether antibody‐decorated, antigen‐pulsed B cells could prime T cells in viro was investigated. Some priming activity was found.
The Primary Structure of Rabbit Serum Amyloid A Protein Isolated from Acute Phase Serum
Authors: SYVERSEN P. V. , JUUL J. , RYGG M. , SLETTEN K. , HUSBY G. , MARHAUG G. 
Published: July 2006

Serum amyloid A (SAA) protein, a sensitive acute phase protein and the precursor of protein AA in secondary amyloid, was purified from pooled acute phase rabbit serum using two different methods: isolation of protein SAA directly by octyl‐Sepharose chromatography of total serum, and dissociation and isolation of apoSAA from acute phase high density lipoprotein (HDL). The protein SAA fraction obtained was further purified using gel filtration and ion exchange chromatography.Rabbit protein SAA has 104 amino acid residues, like human SAA, and has a partially blocked N terminus. The highly conserved region from position 33 to position 63 found in SAA from all species studied was confirmed also in rabbit SAA. No microheterogeneities were observed.The amino acid sequence showed extensive N‐terminal homology with the rabbit amyloid A protein, except for the microheterogeneity in position 12 in protein AA. It also showed identical amino acid sequence with that deduced from the rabbit cDNA clone pSAA 55. Complete homologies were found with clone SAA 2, except for positions 22 and 78, clone SA8‐1, except for positions 22 and 79 and clone SA7‐3, except for position 22. This pSAA 55/SA7‐3/SA8‐l/SAA2‐like protein was the only SAA isotype found both in total serum and in the HDL fraction. Isotypes corresponding to other SAA‐like genes could not be found in this pool of acute phase rabbit sera.
Cholera Toxin Enhances Alloantigen Presentation by Cultured Intestinal Epithelial Cells
Authors: BROMANDER A. K. , KJERRULF M. , HOLMGREN J. , LYCKE N. 
Published: July 2006

In the present study we show that cholera toxin (CT) strongly potentiates antigen presentation by intestinal epithelial cells, probably by enhancing co‐stimulation. This was demonstrated in an allogeneic system using cells from the IEC‐17 rat epithelial cell line as antigen presenting cells (APC). These cells were induced by optimal concentrations of IFN‐γ to express good amounts of Ia antigen and cultured for 24–48 h in the presence or absence of CT. Thereafter the cells were thoroughly washed and added to cultures containing MHC‐incompatible spleen cells as responder cells. Epithelial cells exposed to CT demonstrated greatly enhanced ability to trigger allogen‐specific T‐cell proliferation as compared with IEC‐17 cells treated with IFN‐γ alone. The mechanism for the enhanced APC function was investigated by analysing CT‐treated IEC‐17 cells for increased class II MHC antigen expression or enhanced production of cytokines with known co‐stimulatory function. We found no significant increase in class II MHC antigen expression. By contrast, CT strongly promoted, in a dose‐dependent fashion, the production of both IL‐1 and IL‐6 cytokines by IEC‐17 cells as compared with untreated epithelial cells. This effect of CT was specific and not due to contaminating endotoxin because excess amounts of soluble toxin receptor, ganglioside GM1, added to the IEC‐17 cultures completely abrogated the cytokine response to CT.These results together with our previous findings of enhanced antigen presentation by macrophages stimulated by CT suggest that the potent adjuvant function of CT for induction of mucosal immune responses might be attributed to an enhanced co‐stimulating ability of several putative APC in the mucosal immune system: macrophages, B cells and epithelial cells.
Preparation and Reactivities of Anti‐Porcine CD44 Monoclonal Antibodies
Authors: YANG H. , HUTCHINGS A. , BINNS R. M. 
Published: July 2006

Five monoclonal antibodies (MoAbs) were raised against porcine soluble CD44. The MoAbs recognized the same antigen on the surface of porcine lymphocytes as was recognized by anti‐human CD44 MoAb Hermes‐1, but identified five different epitopes. They bound to most porcine leucocytes but not to red cells. The epitopes were susceptible to treatment with papain or bromelain, whereas trypsinization of porcine leucocytes only reduced the antigen density. The epitopes seem to be co‐expressed among various lymphoid tissues.The MoAbs also cross‐reacted to various degrees with leucocytes of humans, dogs, sheep, cattle, goats and horses, suggesting that the corresponding epitopes arc differentially conseted atnong species.
B‐ and T‐Lymphocyte Subset Numbers in the Migrating Lymphocyte Pool of the Rat: the Influence of Interferon‐γ on its Mobilization Monitored through Blood and Lymph
Authors: WESTERMANN J. , MATYAS J. , PERSIN S. , VAN DER MEIDE P. , HEERWAGEN C. , PABST R. 
Published: July 2006

The subset composition of the migrating lymphocyte pool is largely unknown. In order to determine the number of B, T, CD8 +, CD4+ and CD4+‘naive’(CD45RC+) and ‘memory’ (CD45RC−) lymphocytes in this pool, the thoracic duct lymph of the rat was drained for 7 days. The effect of lymphocyte deplction on the number of blood lymphocytes was also monitored. In addition, the influence of continuously applied interferon‐γ (IFN‐α) on the mobilization of the migrating lymphocyte pool was investigated.Within 1 week 2 × 109 thoracic duct lymphocytes (TDL) were collected, which represents about 50% of the total lymphocyte pool of an adult rat. Among the migrating lymphocytes an early and a late mobilized population could be differentiated. In the former the CD4+‘naive’ (CD45RC+) T lymphocytes constituted the largest population, whereas in the latter it was the B lymphocytes.Continuous infusion of IFN‐γ did not affect the number of lymphocytes in the blood. In contrast, in the thoracic duct IFN‐γ reduced the appearance of all lymphocyte subsets. However, the pattern of reduction over time differed markedly depending on the population (early or late mobilized) and the phenotype (B‐ or T‐tymphocyte subsets.
Phenotypic Characterization of the Human Mast‐Cell Line HMC‐1
Authors: NILSSON G. , BLOM T. , KUSCHE‐GULLBERG M. , KJELLEN L. , BUTTERFIELD J. H. , SUNDSTRÖM C. , NILSSON K. , HELLMAN L. 
Published: July 2006

The cell line HMC‐1, derived from a patient with mast cell leukaemia, is the only established cell line exhibiting a phenotype similar to that of human mast cells. This paper reports on a detailed characterization of the expression of a panel of markers for various types of immature and mature haematopoietic cells in the HMC‐1. We also studied the potential of HMC‐1 to differentiate upon treatment with conditioned media from the human T‐cell line Mo, retinoic acid or DMSO.HMC‐1 was found to express several mast cell‐related markers. A high expression of Kit, the receptor for stem‐cell factor, was detected. The majority of the cells were stained with a MoAb against the mast cell‐specific serine protease tryptase. Of particular interest was the finding that β‐tryptase mRNA, but not a‐tryptase mRNA, was expressed in HMC‐1. Using enzyme‐histochemistry we were able to show that the β‐tryptase was enzymatically active, indicating that tryptase can form active homotetramers. Both heparin and chondroitin sulfate were found to be present in approximately equal amounts. HMC‐1 lacked surface expression of the high‐affinity IgE receptor, which was confirmed by the absence of mRNA of the α‐ and β‐chains of the IgE‐receptor complex. However, a strong expression of the 7‐chain of the IgE‐receptor complex was detected. A positive staining of the monocyte/macrophage marker CD68 was obtained, as well as a strong hybridization signal for the eosinophilic/basophilic‐related differentiation marker the Charcot‐Leyden crystal. Treatment of HMC‐1 with conditioned media from the human T‐cell line Mo, retinoic acid or DMSO induced only moderate changes in the surface or intracellular expression of the studied markers. The agents tested neither induced any of the monocyte/ granulocyte markers examined, nor expression of the FceRIα‐chain.
In Vivo Study of mIgM and mIgD Cross‐Linking on Murine B Cells
Authors: DENIS O. , MACEDO‐SOARES F. , LATINNE D. , NISOL F. , BAZIN H. 
Published: July 2006

In this study, we have analysed in mice the effects on the immune response of in vivo treatment with different rat monoclonal antibodies (MoAb) against IgM and IgD. Although the effects of IgD cross‐linking have been studied already, no attempt has been made to characterize the effects of in vivo IgM crosslinking, probably because of the higher IgM serum levels compared to IgD.We have used a panel of nine monoclonal rat anti‐mouse IgM and three anti‐IgD antibodies and we have characterized their isotypes, avidities, immunoglobulin (Ig) cross‐linking and internalization abilities. Our results show that injection of mice with some rat MoAb against IgM led to an important decrease of IgM serum level and internalization of membrane IgM (mIgM) on almost all B cells. Similarly, treatment with a high‐avidity anti‐IgD antibody induced disappearance of mIgD on B cells. Treatment with rat MoAb against IgM or IgD led to a synthesis of specific antibodies and there was a direct relationship between the Ig internalization abilities of rat MoAb and the induction of specific antibody production. Finally, treatment with a high‐avidity rat MoAb against IgD induced a polyclonal IgE and IgGl secretion. The significance of these results on mIg receptor functions is discussed.
Anti‐CD45 Augments Response of a Th2 Clone to TCR Cross‐Linking
Authors: WOLFF H. , JR C. JANEWAY 
Published: July 2006

The CD45 molecule is a transmembrane tyrosine phosphatase that may be associated with the T‐cell receptor (TCR). This has led to the suggestion that CD45 may be important for the regulation of signal transduction in T cells. This idea is supported by the finding that antibodies against CD45 are comitogenic in proliferation assays.In the present work, we have examined the comitogenicity of CD45 antibodies by studying the effect of CD45, CD45RA, and CD45RB monoclonal antibodies (MoAbs) on proliferation of D10 cells induced with T‐cell receptor (TCR) MoAbs. In addition interactions with some other proliferation inducing agents namely CD3 antibodies, lectins, and IL‐2, are examined here. We have found that in general the CD45 MoAbs would significantly enhance proliferation induced by a wide spectrum of TCR MoAbs and other proliferation inducing agents, with some minor quantitative differences. The CD45 and CD45RB MoAbs were equally potent in their comitogenic activity while the CD45RA antibody was somewhat less potent. The comitogenic effect was maximal when CD45 antibodies were added simultaneously with the TCR MoAb, but significant comitogenicity could be detected when CD45 MoAbs were added up to 24 h after the initiation of the culture indicating that the CD45 antibodies also affect other processes than the initial signal transduction cascade.
The Cross‐Reactive Idiotopes Recognized by the Monoclonal Antibodies 9G4 and LCI are Located in Framework Region 1 of Two Non‐Overlapping Subsets of Human VH4 Family Encoded Antibodies
Authors: POTTER K. N. , LI Y. C. , CAPRA J. D. 
Published: July 2006

The monoclonal anti‐idiotopic antibodies LCI and 9G4 bind two non‐overlapping sets of VH4 encoded antibodies. 9G4 exclusively binds VH4–21 encoded antibodies, while LCI binds antibodies derived from VH4 family gene segments V71‐2, V71‐4, VH4‐18, VH72‐I and V2‐1. The VH4–21 gene segment is utilized by most cold agglutinin (CA) antibodies with I/i specificity, while antibodies encoded by other VH4 gene segments are associated not with CA disease, but primarily with rheumatoid‐factor (RF) activity.We previously determined that the idiotope to which 9G4 binds in VH4‐21‐derived antibodies is located in framework region l (FR1). In the present study, by using mutational analysis involving individual framework‐ and complementarity‐determining region exchanges between VH4‐2I‐ and V71‐2‐encoded antibodies, we have found that the idiotope to which LCI binds in V71‐2‐derived antibodies also maps to FR1. The LC1 idiotope is heavy (H)‐chain associated, but requires pairing with a light (L) chain for LCI binding. Recombinant antibodies composed of a variety of kappa (k) and lambda L chains paired with either a V71‐2 or VH4–21 chain were produced in the baculovirus expression system. LCI bound all of the k‐containing antibodies but did not bind the V71‐2‐encoded H chain alone nor to the two A‐containing antibodies. This experiment demonstrates that not all light chains exert equivalent influence on the conformation of the H‐chain idiotope. These results indicate that the FR1 of VH4‐encoded antibodies is immunogenic and suggest a physiological role of FR l during an immune response.