bluuebunny/crossref_metadata_2025_split huggingface dataset:
The set of naturally processed peptides displayed by DR molecules is tuned by polymorphism of residue 86
Authors: Demotz Stéphane , Barbey Catherine , Corradin Giampietro , Amoroso Antonio , Lanzavecchia Antonio 
Published: March 2007

AbstractThe response to tetanus toxoid (TT) was studied in immune donors that carry two alleles of DR5 that differ only at DRβ residue 86: DRB1*1101 (G86, abbreviated 1101) and DRB1*1104 (V86, abbreviated 1104). A large number of TT‐specific T cell clones was isolated and the epitopes recognized in association with 1101 and 1104 were mapped. We found that two epitopes (p2 and p32) can be recognized in association with both 1101 and 1104 while three epitopes (p23, p27 and p30) are recognized in association with 1101, but never in association with 1104.The sets of naturally processed self peptides displayed by 1101 and 1104 were characterized using alloreactive T cell clones. We found that all 1104 alloreactive clones recognize both 1104 and 1101, while ˜30% of the alloreactive 1101 clones fail to recognize 1104. Thus it is apparent that both naturally processed TTand self peptides displayed on 1104 molecules represent a fraction of those displayed on 1101 molecules.The mechanism responsible for this differential presentation was investigated by comparing the capacity of 1101 and 1104 antigen‐presenting cells to present TTor synthetic peptides to specific T cells and by measuring the binding of these peptides to DR molecules. Three sets of results suggest that V86 acts as a constraint to the binding of naturally processed peptides: (i) all 1104‐restricted or alloreactive T cell clones recognize TT‐ or allo‐epitopes presented by 1101 as well, thus ruling out a major effect of V86 as a residue determining T cell restriction specificity; (ii) presentation of naturally processed peptides correlates in general with the capacity of long synthetic peptides to bind to 1101 or 1104 and (iii) while the naturally processed p30 epitope discriminates between 1101 and 1104, a short synthetic peptide binds equally well to and is comparably recognized in association with both 1101 and 1104.Taken together these results suggest that the natural polymorphism at residue 86 might be a molecular switch that finely tunes the complexity of the peptide collection presented on DR molecules.
Protective immunity induced in rat schistosomiasis by a single dose of the Sm28GST recombinant antigen: Effector mechanisms involving IgE and IgA antibodies
Authors: Grezel Delphine , Capron Monique , Grzych Jean‐Marie , Fontaine Josette , Lecocq Jean‐Pierre , Capron Andre 
Published: March 2007

AbstractRats immunized by a single dose of the recombinant Sm28GST antigen, using either aluminium hydroxide or Bacillus Calmette‐GuSrin adjuvant, were significantly protected (up to 59% reduction in worm burden) against a challenge infection with Schistosoma mansoni cercariae. A follow‐up study of the humoral response revealed the presence of high levels of IgE and IgA antibodies together with specific IgG. Sera from once Sm28GST‐immunized rats induced a cytotoxic response for schistosomula targets in the presence of normal rat eosinophils, similar to the one induced by sera from twice immunized rats. Depletion or competition studies indicated the participation of both IgE and IgA antibodies in eosinophil‐dependent cytotoxicity mechanisms.These results suggest the existence, in immunized rats exhibiting protection against schistosomiasis, of an original effector mechanism implying eosinophils and IgA antibodies, together with documented effector mechanisms involving IgE and eosinophils. In addition, they raise questions concerning the role of IgA antibodies in schistosomiasis.
Cross‐linking of surface IgM, but not surface IgD receptors, by soluble monoclonal antibodies primes murine B cells to secrete immunoglobulin in response to lymphokines
Authors: Phillips Catherine , Klaus Gerry G. B. 
Published: March 2007

AbstractWe have previously reported the development of a two‐step culture system in which soluble anti‐μ monoclonal antibodies prime small resting murine B cells to secrete immunoglobulin (Ig) in response to restimulation with a mixture of interleukin‐4 (IL‐4) and IL‐5. Here we have extended these studies to investigate the effects of engaging surface IgD (sIgD).We find that, unlike anti‐μ, three different anti‐5 monoclonal antibodies did not prime B cells to secrete Ig. In addition, these anti‐δ antibodies inhibited anti‐μ‐stimulated priming for Ig secretion, while enhancing DNA synthesis in response to anti‐μ,. Furthermore, anti‐δ antibodies still inhibited anti‐μ‐induced priming when added 24‐48 h after anti‐μ. These results therefore suggest that triggering of sIgD on B cells induces a dominant inhibitory signal which is not necessarily dependent upon co‐ligation of sIgM and sIgD receptors. In addition, these findings raise the possibility that ligating sIgM or sIgD receptors on mature B cells in the absence of Tcell help, may produce different downstream effects.
The T cell receptor αβ V‐J shuffling shows lack of autonomy between the combining site and the constant domain of the receptor chains
Authors: Casorati Giulia , Traunecker André , Karjalainen Klaus 
Published: March 2007

AbstractIn order to assess the structural independence of the T cell receptor (TCR) combining site from the rest of the molecule we have generated two recombinant chains consisting of aTCR V‐J α region linked to the Cβ and aTCR V‐J β linked to the Cα. If the V and C domains of the TCR form independent domains, as has been shown for the Ig molecules, we would expect to obtain a functional chimeric TCR. Interestingly, it was found that the shuffled molecules are produced intracellularly in T cell hybridomas, but are not expressed on the cell surface. To explain this failure of the shuffled molecules we propose that the TCR has a more compact structure, compared to the Ig, and that it is indispensable to keep a longitudinal inter‐domain contact between the V‐J and C portion to have a functional molecule.
A promoter element of the human serine esterase granzyme B gene controls specific transcription in activated T cells
Authors: Haddad Patrick , Wargnier Alain , Bourge Jean‐François , Sasportes Maryline , Paul Pascale 
Published: March 2007

AbstractThe human granzyme B gene encodes a serine protease expressed specifically in cytoplasmic granules of cytotoxic T lymphocytes, released upon effector‐target cell interaction. Previous studies have shown that granzyme B mRNA was induced in T lymphocytes after antigenic or mitogenic stimulation. To study the regulation of human granzyme B gene expression during lymphocyte activation we analyzed its 5′ flanking region using chloramphenicol acetyl transferase (CAT) reporter gene constructs. We show that a 208‐bp fragment (‐148 to +60) containing an NF‐AT (nuclear factor of activated T cells)‐binding site promotes CAT expression in phytohemagglutinin‐activated T lymphocytes, in immobilized monoclonal anti‐CD3 antibody‐activated Jurkat T cell line while it is inactive in unstimulated PEER and Jurkat T cells lines or B Epstein‐Barr virus‐transformed cell lines.
Expression and control of the natural autoreactive IgG repertoire in normal human serum
Authors: Hurez Vincent , Kaveri Srinivas‐ V. , Kazatchkine Michel D. 
Published: March 2007

AbstractWe have investigated the autoreactive repertoire expressed by serum IgG of healthy individuals of various age groups using a large panel of self antigens. Natural IgG autoantibodies against all self antigens of the panel were found in the purified IgG fraction of the serum of all donors that were tested. The mean binding activity to self antigens of IgG of pregnant women was higher than that of IgG purified from the serum of infants, young adults and aged individuals. No increase in IgG autoreactivity was observed with aging neither in the purified IgG fraction of serum nor in whole serum. Whereas autoantibody activity was easily detectable in purified IgG, it was low in serum. No difference was observed, however, between the binding activity of purified IgG and of IgG in serum in the case of foreign antigens nor in the case of anti‐thyroglobulin autoantibodies of patients with Hashimoto's thyroiditis. Purified IgM from normal serum bound to F(ab')2 fragments of autologous IgG in a dose‐dependent fashion and inhibited the binding of autologous IgG to self antigens. Our results thus indicate that autologous IgM contributes to regulate expression of the natural IgG autoreactive repertoire through V region‐dependent interactions, resulting in low levels of IgG autoreactivity in serum under physiological conditions.
Normal T cell receptor Vβ usage in a primary immunodeficiency associated with HLA class II deficiency
Authors: Rieux‐Laucat Frédéric , le Deist Franchise , Selz Franchise , And Alain Fischer , de Villartay Jean‐Pierre 
Published: March 2007

AbstractThe human Tcell receptor was studied using an anchored‐polymerase chain reaction (A‐PCR) and hybridization with Vβ‐specific oligonucleotide probes, together with the few anti‐Vβ monoclonal antibodies (mAb) available. After confirming the semiquantitative and reproducible nature of the A‐PCR technique, we assessed the complete Vβ repertoire in sorted CD4+ and CD8+ lymphocyte populations from three normal donors. These experiments confirmed the absence of Vβ‐restricted deletions in human peripheral cells, in contrast to several mouse strains. This feature makes it difficult to study negative selection in man, given the apparent absence of an endogenous superantigen corresponding to the Mis system in the mouse. To investigate human Vβ repertoire shaping, we studied VP usage in CD4+ and CD8+ T cells from children with an inherited immunodeficiency characterized by defective expression of human leukocyte antigen class II molecules. An initial study using anti‐Vβ monoclonal antibodies failed to show significant abnormalities in Vβ usage. Four patients analyzed using the A‐PCR method all had a polyclonal Vβ repertoire, suggesting normal positive selection and raising questions as to the importance of VP major histocompatibility complex (MHC) interactions and the role of thymic MHC density in shaping the Vβ repertoire.
Cloning and expression of murine CD27: comparison with 4‐1BB, another lymphocyte‐specific member of the nerve growth factor receptor family
Authors: Gravestein Loes A. , Blom Bianca , Nolten Linda A. , de Vries Evert , Horst Gerda Van Der , Ossendorp Ferry , And Jannie Borst , Loenen Wil A. M. 
Published: March 2007

AbstractCD27 is a member of the nerve growth factor receptor family, that includes two types of tumor necrosis factor receptor, CD40 and Fas/Apo‐1. Human CD27 has been found only on lymphocytes. In T cells, its expression strongly increases in a transient fashion upon antigenic stimulation, suggesting that CD27 plays a role during T cell activation. To analyze the function of CD27, we have identified the murine CD27 at the cDNA and protein level. Murine CD27 shows an identity of 65% compared with human CD27. The amino‐terminal cysteine‐rich region, i.e. the putative ligand‐binding domain, and the carboxy‐terminal part of the cytoplasmic domain are approximately 80% identical in man and mouse. Murine CD27 has 29% identity to 4‐IBB, another lymphocyte‐specific member of the receptor family defined only at the cDNA level. Murine CD27 and 4‐1BB have 39% homology in the cysteine‐rich domain and share a conserved region in the cytoplasmic tail. Expression studies identified murine CD27 mRNA in thymus and spleen, but not in non‐lymphoid tissues, while 4‐IBB mRNA was not detected in any tissue tested. In resting T cells, only murine CD27 mRNA was found, while in activated T cells murine CD27 as well as 4‐1BB were present at high levels. Murine CD27 and 4‐1BB mRNA are expressed with different kinetics during T cell activation, suggesting that these molecules play different roles in this process. Peptide antisera identified murine CD27 as a 45‐kDa protein on thymocytes and activated T cells, while 4‐1BB was precipitated as a 35‐40‐kDa protein from activated T cells.
The transcription factor Pit‐l/GHF‐1 is expressed in hemopoietic and lymphoid tissues
Authors: Delhase Mireille , Vergani Patricia , Malur Anagha , Hooghe‐Peters Elisabeth L. , Hooghe Robert J. 
Published: March 2007

AbstractThe expression of the Pit‐l/GHF‐1 transcription factor (hereafter Pit‐1), which controls the expression of growth hormone (GH) and prolactin (PRL) in the pituitary gland, has been documented in human and rat hemopoietic and lymphoid tissues and cell lines. Pit‐1 mRNA was detected by in situ hybridization in about 1 % of rat bone marrow cells and in the spleen red pulp and marginal zone. Pit‐1 was also expressed in human tonsils (mantle zone), in the thymus (rat and human, non‐lymphoid cells), in lipopolysaccharide‐stimulated rat peritoneal cells and in non‐hepatocyte cells in the liver (rat and human). A detailed investigation of the rat spleen showed a very similar distribution for Pit‐1, GH and PRL mRNA and Pit‐1, GH and PRL proteins (detected by immunocytochemistry). Using polymerase chain reaction followed by Southern hybridization, the expression of Pit‐1 could be confirmed in human and rat spleen, bone marrow and thymus. HL60 and RAJI leukemic cells were also positive. The sequence of fragments amplified from rat spleen and from human bone marrow completely matched published sequences of rat and human pituitary Pit‐1, respectively. Expression of GH and PRL in lymphoid tissues has been documented. The straightforward hypothesis would therefore be that Pit‐l's main function in lymphoid tissues is controlling GH and PRL expression, as in the pituitary gland. GH and PRL may be hemopoietic and lymphoid growth and differentiation factors.
Serum soluble interleukin‐6 receptor in MRL/lpr mice is elevated with age and mediates the interleukin‐6 signal
Authors: Suzuki Hiroshi , Yasukawa Kiyoshi , Saito Takashi , Narazak Masashi , Hasegawa Atsuhiko , Taga Tetsuya , Kishimoto Tadamitsu 
Published: March 2007

AbstractThe characteristics of soluble interleukin‐6 receptor (sIL‐6R) in murine sera were examined. To investigate a relationship between serum sIL‐6R level and autoimmune diseases, quantitative analysis of serum sIL‐6R in MRL/lpr mice was performed by an enzyme‐linked immunosorbent assay. The serum sIL‐6R level in MRL/lpr mice of both sexes was below the detection limit (< 1.0 ng/ml) at 8 weeks of age, but it increased in accordance with age and reached 42 ± 9.3 ng/ml in female and 31 ± 13 ng/ml in male mice at 30 weeks of age. In MRL/+ mice, although an age‐associated increase in serum sIL‐6R level was observed, it was much less extensive than that in MRL/lpr mice. Elevated serum sIL‐6R level at the age of 30 weeks was observed in female and male (NZB × NZW)F1 mice (32 ± 10 ng/ml and 17 ± 5.0 ng/ml, respectively), and male BXSB/Mpj Yaa mice (42 ± 18 ng/ml), suggesting that elevated serum sIL‐6R in aged mice is one of the characteristics of autoimmune‐prone mice. Quantitative analysis of serum IL‐6 in MRL/lpr revealed that the serum sIL‐6R level correlated well with the serum IL‐6 level. We also showed that sIL‐6R in the sera from MRL/lpr mice could mediate the IL‐6 functions through the IL‐6 signal‐transducing receptor component gpl30, suggesting that elevated production of sIL‐6R may partly contribute to development of autoimmune disease in MRL/lpr mice.
The level of N‐region diversity in T cell receptors is not pre‐ordained in the stem cell
Authors: Bogue Molly , Mossmann Horst , Stauffer Uta , Benoist Christophe , Mathis Diane 
Published: March 2007

AbstractThe αβ Tcell repertoires of adults and neonates are distinctly different. For example. Tcell receptors (TcR) from adult animals have substantial N‐nucleotide addition at their V‐D‐J junctions while those from neonatal animals do not. This dichotomy reflects a rather abrupt change in expression of the terminal deoxynucleotidyl transferase (TdT) gene in thymocytes on day 4 after birth. We have asked whether this change is due to the differentiation of successive waves of stem cells harboring different potentials for TdT expression, a scenario like the one proposed to explain developmental regulation of γδ Tcell repertoires. Reconstitution of adult severe combined immunodeficiency mice with either fetal liver or adult bone marrow precursors gave rise to T cells with substantial N‐region diversity in their TcR, even at the earliest points of reconstitution. It is most likely, then, that the abrupt change in TdT gene expression in day 4 thymocytes is due to an environmentally induced switch‐on.
Synovial IgG rheumatoid factors show evidence of an antigen‐driven immune response and a shift in the V gene repertoire compared to IgM rheumatoid factors
Authors: Randen Ingrid , Pascual Virginia , Victor Kimberly , Thompson Keith M. , Førre Øystein , Capra J. Donald , Natvig Jacob B. 
Published: March 2007

AbstractWe have established IgG rheumatoid factor (RF)‐secreting hybridoma cell lines from the synovial tissues of three patients from whom we have previously characterized several IgM RF. The IgG RF bind human and rabbit IgG and form intracellular complement‐fixing complexes indicative of a self association process in vivo. Nucleotide sequence analysis revealed that two IgG RF used VHIII gene segments, while one used a VHI gene segment. The VL gene usage consisted of a Vχ1, a Vλ2 and a Vχ4/Vχ6 hybrid, confirming our previous findings that many different VL genes can contribute to RF specificity. Although the IgG RF used VH genes from the same families that dominated the IgM RF response, two of the actual gene segments employed were not found among the IgM RF. In contrast to IgM RF, which in general were not very mutated, the IgG RF showed somatic mutations characteristic of an antigen‐driven immune response.
Membrane cofactor protein (MCP, CD46) in seminal plasma and on spermatozoa in normal and “sterile” subjects
Authors: Seya Tsukasa , Hara Tomoko , Matsumoto Misako , Kiyohara Hisakazu , Nakanishi Isao , Kinouchi Toshiaki , Okabe Masaru , Shimizu Akira , Akedo Hitoshi 
Published: March 2007

AbstractA sperm protein of molecular mass 43 kDa (the spermatozoa membrane cofactor protein, smMCP) and a seminal plasma protein of 60 kDa (ssMCP) were identified by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) followed by immunoblotting with four monoclonal antibodies (mAb) against membrane cofactor protein (MCP, CD46).These proteins served as factor I cofactors for the cleavage of methylamine‐treated C3 (C3ma), the activity of which was blocked by M75, an MCP cofactor‐activity‐blocking mAb. Thus, these semen proteins are antigenic and functional homologoues of MCP. On SDS‐PAGE analysis these MCP migrated as single‐band proteins which differed from the two‐band forms of MCP expressed on other cells. smMCP was N‐glycosylated but not O‐glycosylated, while ssMCP was O‐glycosylated: after deglycosylation of these proteins bands were detected at 38‐40 kDa and 43 kDa on SDS‐PAGE, respectively. These semen MCP are therefore, structurally different from the conventional MCP. ssMCP in both normal and “sterile” subject groups was determined by sandwich enzyme‐linked immunosorbent assay. Seminal plasma in the two groups contained 250‐700 ng/ml ssMCP. The difference between the two groups was marginal, although samples from normal subjects tended to show higher concentrations of ssMCP than samples from “sterile” subjects. No molecular difference was observed with ssMCP and smMCP in the two groups by SDS‐PAGE/immunobloblotting analysis. Immunohistochemical analysis suggested that MCP was positive in glandular epithelial cells and the lumen of the prostate, and in most intra‐lumen cells of the testis. Using antibody M177, solubilized prostate and testis were analyzed by immunoblotting and compared with other cell MCP The major band of MCP in the testis, but not in the prostate, was of 60 kDa, which aligned with ssMCP. No band of testis or prostate MCP, however, aligned with smMCP. ssMCP may be produced in the testis, while the origin of smMCP remains unknown. We hypothesize that ssMCP is important in the survival of spermatozoa, protecting them against local secretion of immunoglobulin and complement in the female genital tract, and that smMCP, which is expressed on acrosome‐reacted spermatozoa, plays an essential role in the interaction of spermatozoa with oocytes.
Mouse Crry/p65 is a regulator of the alternative pathway of complement activation
Authors: Foley Sharon , Li Bin , Dehoff Marlin , Molina Hector , Holers V. Michael 
Published: March 2007

AbstractLike man, mouse has evolved a unique set of regulatory proteins which provide protection from complement‐mediated damage to self membranes. The recently described mouse protein Crry/p65 has been shown to inhibit classical complement pathway C3 deposition on cell membranes in which it is expressed. In two distinct experimental systems, we now further delineate the regulatory activity of Crry/p65 and demonstrate its inhibitory effect on alternative complement pathway C3 activation. First, significant inhibition of mouse alternative pathway C3 deposition was demonstrated on neuraminidase‐treated human K562 cells expressing recombinant Crry/p65. Second, using a baculovirus technique, recombinant Crry/p65 was synthesized as a soluble molecule and then purified. This molecule was found to inhibit mouse C3 deposition on the surface of zymosan, a potent alternative complement pathway activator. These studies, combined with our earlier findings, demonstrate that Crry/p65 can regulate both the classical and alternative complement pathways. Crry/p65 must, therefore, exert its effects prior to, or at the level of, the C3 convertases, in a fashion similar to that of human membrane cofactor protein and/or decay‐accelerating factor. These studies provide further proof of the hypothesis that Crry/p65 is an evolutionarily unique, complement regulatory protein which has developed in mouse.
Cloning and sequencing of human immunoglobulin λ. gene segments
Authors: Williams Samuel C. , Winter Greg 
Published: March 2007

AbstractTo provide the building blocks for making synthetic antibody fragments we have used the polymerase chain reaction (PCR) to clone human variable (V) gene segments of λ light chains. The PCR primers were based on the sequences of known human Vλ segments, and were used to isolate 14 new Vλ segments (including 4 pseudogenes) from a single individual. We have compiled a sequence directory from this data and other sources to include all known human Vλ segments with open reading frames and we have identified a new Vx family (Vλ IX). Almost all of the segments (22/24) have different sequences in the complementarity‐determining regions, setting a lower limit to the structural diversity of the antigen binding sites encoded by human Vλ genes in the human population.