bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions between human eosinophils and schistosomula of schistosoma mansoni. II. The mechanism of irreversible eosinophil adherence
Authors: Butterworth AE , Vadas MA , Wassom DL , Dessein A , Hogan M , Sherry B , Gleich GJ , JR David 
Published: June 2004

Previous work (1)(1) has shown that normal human eosinophils show a preferential capacity, in comparison with neutrophils, to bind to antibody- coated schistosomula of Schistosoma mansoni. This effect is attributable to a temperature-dependent function of the eosinophil which renders its binding stable and irreversible by aggregated gamma globulin or Staphylococcus aureus protein A. In contrast, the binding of neutrophils is readily reversible by these agents.
It has now been shown that the differences observed between eosinophils and neutrophils is a property of their interaction with living schistosomula. When dead or artificially damaged schistosomula were tested, neutrophils showed a markedly enhanced capacity to adhere, in both the presence and absence of anti-chistosomular serum.
Subsequent experiments were designed to test the hypothesis that the strong, stable binding of eosinophils was attributable to degranulation, with release of granule contents which would then serve as ligands to bind the cell to the organism. First, an enhanced adherence both of eosinophils and of neutrophils could be demonstrated in the presence of eosinophil major basic protein (MBP) or of protamine, a high molecular weight cation. Second, the binding of eosinophils induced by concanavalin A (Con A) was found to differ markedly from that induced by antischistosomular serum. Con A-mediated binding of eosinophils was fully reversible by alpha-methyl-mannoside, was not associated with damage to the organism, and did not lead to degranulation of the cell, as estimated by measuring the release of MBP into the culture supernate. However, induction of degranulation of concanavalin A-bound eosinophils, but not of neutrophils, with the calcium ionophore A23187 converted the reaction into one which was no longer reversible by alpha- methylmannoside and in which damage to the organism now did occur.
These findings support the hypothesis that the stable binding of eosinophils is associated with degranulation, a process which may contribute to the preferential capacity of this cell to mediate antibody-dependent damage to schistosomula.
Evolutionary conservation of surface molecules that distinguish T lymphocyte helper/inducer and cytotoxic/suppressor subpopulations in mouse and man
Authors: Ledbetter JA , Evans RL , Lipinski M , Cummingham-Rundles C , Good RA , Herzenberg LA 
Published: June 2004

We describe the biochemical properties and cell surface distributions of three human T cell antigens (Leu-1, Leu-2a, and Leu-2b) which we postulate to be the homologues of the Lyt-1, Lyt-2, and Lyt-3 antigens that distinguish functional T cell subsets in the mouse. Leu-l, like Lyt-1, is on all thymocytes and peripheral T cells and is present in greater amounts on the helper/inducer subset than on the cytotoxic/suppressor subset. Both antigens increase in parallel fashion during T cell maturation in the thymus and each antigen is carried on a single 67,000-molecular weight (relative) (M(r)) polypeptide chain. Surprisingly, Leu-1 and Lyt-1 each are also expressed in readily detectable amounts on some B celI Ieukemias but not detectably so on normal B cells.
Leu-2a and Leu-2b are antigens found only on suppressor/cytotoxic cells in the human and are very similar to the murine Lyt-2 and Lyt-3 antigens. In both species, the two antigens are on the same disulfide- linked multimeric molecules. Disulfide-bond reduction in both species yields subunits of similar size and charge. Lyt-3 and Leu-2b are extremely sensitive to trypsin digestion on viable cells whereas Lyt-2 and Leu-2a are much less so.
A different membrane antigen, Leu-3, is an exclusive marker of the helper/inducer subset in man. No mouse homologue for this 55,000-M(r) protein is known.
The maintenance of the homologous molecules on functionally distinct T cell subpopulations in two evolutionarily distant species suggests that the Lyt and Leu antigens perform essential functions for the cells on which they are found.
Antigen-inducible, H-2-restricted, interleukin-2-producing T cell hybridomas. Lack of independent antigen and H-2 recognition
Authors: Kappler JW , Skidmore B , White J , Marrack P 
Published: June 2004

We developed a method for production of antigen-specific, H-2-restricted T cell hybrids. The tumor cell partner in the fusions was itself a T cell hybrid, FS6-14.13.AG2 (or its derivatives), which could be induced to produce the growth factor, interleukin-2 (IL-2), in response to a challenge with concanavalin A, but had no known antigen specificity. The normal T cell partner in the fusions was a population of lymph node T cell blasts that had been highly enriched in antigen-specific, H-2-restricted T cells by in vivo immunization, followed by in vitro challenge with antigen and clonal expansion in IL-2-containing medium. These fusions produced hybrids that grew constitutively in culture. A sizable proportion of the hybrids demonstrated the ability to produce IL-2 in response to a challenge with specific antigen presented by irradiated spleen cells of the appropriate H-2 type.
Four cloned antigen/H-2-specific hybrid lines were produced. AO-40.10 responded to chicken ovalbumin (OVA) when presented by I-A(k)-bearing cells. DC1.18.3 responded to the apo form of beef cytochrome c when presented with I-A(d). AODK-10.4 responded to keyhole limpet hemocyanin (KLH) presented with I-A (d). AODK-1.16 also responded to KLH presented by a product of the I region of H-2(d), but the data were consistent with either a product of the I-J-I-E(d) region or a combinatorial molecule with elements from both I-A(d) and I-E(d)/I-C(d). Coincidentally, AO-40.10 was shown to have an unexpected alloreactivity with a product of H-2(b) mapping to the K-I-A region. These hybrids should prove invaluable as sources of monoclonal material for the study of the receptor(s) on T cells with H-2-restricted antigen specificities.
We also generated T cell hybrids with two antigen/H-2 specificities by fusing an azaguanine-resistant clone of AO-40.10 to normal T cells with a different antigen/H-2 specificity. Many of the hybrids retained reactivity to OVA plus H-2(a) and to the second antigen/H-2 combination. None reacted to either OVA plus the second H-2 type or to the second antigen plus H-2(a).
One of these hybrids was successfully cloned to produce the line AOFK- 11.11.1. It retained the ability to recognize OVA plus I-A(k) inherited from one parent, and KLH plus IA(f) inherited from the other. It did not recognize OVA plus IA(f) or KLH plus I-A(k).
These results have some bearing on models describing the nature of T cell receptors for antigen recognized in association with H-2 products. They do not support models in which antigen and H-2 are recognized separately by two independent T cell receptors.
Antigen-specific t lymphocyte clones. II. Purifcation and biological characterization of an antigen-specific suppressive protein synthesized by cloned T cells
Authors: Fresno M , McVay-Boudreau L , Nabel G , Cantor H 
Published: June 2004

We have generated an antigen-specific T suppressor clone that synthesizes 70,000-mol wt peptides that have antigen-specific-binding activity. Although these data also indicated that antigen-binding peptides completely inhibited the in vitro primary response to a complex antigen, suppression might reflect the combined biologic activities of many different 70-mol wt polypeptides or polypeptides associated with the 70,000-mol wt material by noncovalent interactions. The protein responsible for antigen-specific suppression was therefore purified to virtual homogeneity after sequential separation of internally labeled supernate peptides on Sephacryl S-200 and DEAE-cellulose columns followed by isoeleetrofocusing. The resulting protein is greater than 95 percent homogeneous according to sodium dodeeyl sulfate-polyacrylamide electrophoresis and represents two peptides having two very close but distinguishable isoelectric point values of approximately 5.0.
The purified molecules are retained by columns coated with lentil lectin or antigen but not by columns coated with antisera specific for immunoglobulins, the I region of the major histocompatibility complex or Ly-1 or Ly-2 antigens. Less than 50 pg of the purified glycoprotein specifically and completely suppresses production of anti-sheep erythrocyte plaque-forming cell by mixtures of 10(6) Ly-1 cells and B cells and this is a result of inactivation of Ly-l-mediated helper function. Specific inactivation of T (Th) cells by the 70,000-mol wt molecule is rapid, specific, and requires the presence of antigen. The mechanism of specific suppression of Th function may depend upon two functionally distinct regions of the 70,000-mol wt molecule: one that binds antigen and a second that mediates suppression.
Studies on the antigenic determinants in the self-association of IgG rheumatoid factor
Authors: Nardella FA , Teller DC , Mannik M 
Published: June 2004

The number, location, and other characteristics of the antigenic determinants for self-association of IgG-rheumatoid factors (IgG-RF) were examined using the IgG-RF isolated from the plasma of one patient as a model system. Affinity chromatography was employed for isolation of the IgG-RF. Sedimentation equilibrium ultracentrifugation was used to study the various interactions.
The antigenic valence of IgG-RF Fc, normal human Fc, and rabbit Fc fragments was two for the interaction with Fab fragments from IgG-RF, as might be expected from the molecular symmetry of IgG. The antigenic valence of intact normal IgG, however, was only one, indicating that when one of the available antigenic determinants interacted with the Fab fragment of IgG-RF, the other determinant becomes sterically inaccessible. Reduction and alkylation, known to increase the flexibility of the hinge region, did not alter the antigenic valence of IgG for Fab fragments of IgG-RF. The antigenic valence of IgG-RF in self-association could not be experimentally determined but must be two to permit the observed concentration-dependent further polymer formation of IgG-RF dimers.
Unique antigenic determinants on the Fc fragments of IgG-RF were sought and not found, thus reaffirming the formation of two antigen-antibody bonds as the basis for dimerization of IgG-RF molecules.
The pFc' and Fc' fragments, representing Cγ3 domains of IgG, failed to show significant interaction with Fab fragments of IgG-RF, indicating that the antigenic determinants were not expressed by the Cγ3 regions but are located either on Cγ2 region or require intact Cγ2 and Cγ3 regions for expression. These conclusions were corroborated by the antigenic valence of one for the Fc(i) fragment, a new papain-generated intermediate fragment of Fc, composed of two intact Cγ3 domains and one intact Cγ2 domain.
Normal IgG, because of its valence of one for interaction with IgG-RF, would effectively terminate further polymerization of IgG-RF dimers. This may well in part explain the finding of smaller IgG-RF complexes in the serum than in synovial fluid of patients with rheumatoid arthritis.
Phenotypic and functional properties of murine thymocytes. I. Precursors of cytolytic T lymphocytes and interleukin 2-producing cells are all contained within a subpopulation of "mature" thymocytes as analyzed by monoclonal antibodies and flow microfluorometry
Authors: Ceredig R , Glasebrook AL , MacDonald HR 
Published: June 2004

The correlation between surface phenotype and function in subpopulations of murine thymocytes has been investigated using flow microfluorometry (FMF). C57BL/6 thymocytes stained with monoclonal antibodies directed against Lyt-2, H-2K(b), and Thy-l.2 and passed on an FACS II flow cytometer could be resolved into at least four distinct subpopulations on the basis of fluorescence and forward light scatter (FLS) measurements. (a) Medium-sized Lyt-2(+) cells that stained strongly with H-2K(b) and weakly with Thy-l.2 (5 percent of total cells); (b) medium-sized Lyt-2(-) cells with other properties as in (a) (10 percent); (c) small Lyt-2(+) cells that stained weakly with H-2K(b) and strongly with Thy-l.2 (60 percent); and (d) large Lyt-2(+) cells that stained weakly with H-2K(b) and very strongly with Thy- 1.2 (23 percent). Cortisone-resistant thymocytes (CRT) were found to correspond phenotypically to populations (a) and (b).
The distribution of cytolytic T lymphocyte precursors (CTL-P) directed against H-2(d) alloantigens in subpopulations of C57BL/6 thymocytes that had been sorted according to the phenotypic criteria described above was then investigated. CTL-P in sorted and control populations were quantitated by limiting dilution analysis of mixed leukocyte microcultures established in an excess of interleukin 2 (IL-2). These studies established that all thymus CTL-P could be quantitatively recovered in a subpopulation of cells that was cortisone-resistant, medium-sized, Lyt-2(+), H-2K(b+), and weakly stained with Thy-l.2.
In parallel studies, the production of IL-2 by subpopulations of C57BL/6 thymocytes was quantitatively assessed using a recently developed sensitive microassay system. Graded numbers of sorted or control thymocytes were stimulated with irradiated T cell-depleted allogeneic cells and assayed for their ability to support the growth of an IL-2-dependent cytolytic T lymphocyte clone. Using this method, IL-2 production was found to reside entirely in a subpopulation of cortisone-resistant, medium-sized Lyt-2(-) thymocytes. Further phenotypic analysis of this subpopulation of cells indicated that it was homogeneously H-2K(b+) and weakly staining with Thy- 1.2. Taken together with the CTL-P results, these data directly demonstrate that a subpopulation of thymocytes with a mature phenotype (i.e., cortisone- resistant, medium-sized, H-2K(b+), and weakly staining with Thy-l.2) accounts for all the functional activity in the thymus. Reasons for the apparent discrepancy between these results and other recent studies will be discussed.
Quantitative studies of in situ immune complex glomerulonephritis in the rat induced by planted, cationized antigen
Authors: Oite T , Batsford SR , Mihatsch MJ , Takamiya H , Vogt A 
Published: June 2004

Cationized human IgG can bind to the rat glomerular basement membrane (GBM), act as planted antigen, and induce in situ immune complex formation accompanied by severe glomerulonephritis. Perfusion of highly cationized human IgG (isoelectric point {more than} 9.5) via the left renal artery resulted in preferential localization within the perfused kidney (up to 56 percent of dose injected); after intravenous administration, only 4 percent was bound to the kidneys. The planted antigen was localized along the glomerular capillary walls and was accessible for antibody administered intravenously 1 h after perfusion, when virtually no antigen remained in the circulation.
Persistence of cationized human IgG in the perfused kidney was markedly prolonged when complexed with antibody; one-half the cationized human IgG was still present after 12 d. There was a difference in the disappearance rates of antigen and antibody, as cationized human IgG was removed faster from the kidney than the antibody, the binding of which remained almost unchanged during the first week. Renal perfusion of a minimum of 20 μg of cationized human IgG, followed by intravenous injection of antibody, regularly induced severe glomerulonephritis with a proteinuria of at least 100 mg/24 h. The degree and the persistence of proteinuria induced depended on the dose of cationized human IgG perfused.
Experiments using radiolabeled antigen and antibody showed that after renal perfusion of 20 μg cationized human IgG, 11.1 μg was kidney bound at the time of antibody injection. At the onset of proteinuria, 4.0 μg of antigen and 31.9 μg of anti-human IgG antibody were present in the perfused kidney. Immunofluorescence revealed immune deposits consisting of cationized human IgG and rabbit IgG (anti-human IgG) along the GBM. The staining pattern was linear (confluent) during the first 2 d and became granular during the course of the disease. Electronmicroscopically, a prominent finding was the accumulation of dense deposits, mainly in the subepithelial space and beneath the slit pores.
The QA2 subregion controls the expression of two antigens recognized by H-2- unrestricted cytotoxic T cells
Authors: Forman J , Trial J , Tonkonogy S , Flaherty L 
Published: June 2004

B6.KI mice were immunized with spleen cells from B6.K2, a Qa2-subregion congenic strain. Cytotoxic T cells were generated that recognize two target antigens controlled by this region.
One of the target antigens is Qa-2. This was demonstrated by the findings that pretreatment of target cells with monoclonal anti-Qa-2 antibody blocked lysis of target cells, and Qa-2 target antigens and serological determinants had a concordant distribution on a panel of B10.W (wild) mice. The gene controlling the Qa-2 target antigen is not polymorphic because B6.K2 and three strains of Qa-2(+) B10.W mice express the same antigens, as determined by a CTL cold target competition assay. Anti-Qa-2 CTL were H-2 unrestricted because effector cells lysed Qa-2(+) targets irrespective of their H-2 haplotype, including five B 10.W strains, and lysis was not inhibited by pretreating target cells with anti-H-2 sera. The Qa2 subregion does not act as a restricting locus for anti-minor-H antigen CTL.
A second target antigen was detected that was associated with the expression of the Qa-5 determinant. However, CTL activity could not be blocked by pretreating target cells with monoclonal anti-Qa-5. Therefore, the CTL target antigen may be expressed on a Qa-5(-) molecule. Although the Qa-5 associated CTL specificity is only detected on H-2D(b) strains, it is unlikely that CTL recognition is H-2 restricted because anti-H-2(b) sera has no effect in blocking this reactivity.
Qa-2 and H-2 class I antigens share a similar structure and serve as target antigens for unrestricted CTL. However, unlike class I H-2 genes, Qa-2 neither restricts antigen-specific CTL nor is polymorphie. Therefore, it is likely that Qa-2 and H-2 are derived from a common ancestral gene and have evolved to serve different functions.
Helper activity is required for the in vivo generation of cytotoxic T lymphocytes
Authors: Keene J-A , Forman J 
Published: June 2004

B6.T1a(a) (Qa-1(a)) mice that are primed in vivo and restimulated in vitro with Qa-1 congenic spleen cells from B6 (Qa-1(b)) animals are unable to generate anti-Qa-1(b) cytotoxic T lymphocytes (CTL). This nonresponsive pattern was observed regardless of the route of immunization or the time of testing in vitro.
Although B6.T1a(a) mice are nonresponders to Qa-1(b) when presented on B6 cells, these mice can generate anti-Qa-1(b) CTL when primed in vivo with Qa-1 and H-Y alloantigens (females primed with B6 male cells) or Qa-1 and minor-H- alloantigens (primed with sex-matched A.BY cells). Therefore, the inability to generate anti-Qa-1(b) CTL is due to a lack of helper or accessory antigens on B6 immunizing cells obligatory during in vivo priming, rather than an absence of anti-Qa-1(b) CTL precursors (CTL-P). Demonstration that the additional determinants required during in vivo priming actually function as carrier or helper determinants was shown by the requirement for linked recognition of Qa-1 and the helper determinants (H-Y) in vivo, and the fact that H-Y was not present on susceptible target ceils. Animals primed in vivo with H-Y only could not generate anti-Qa-1 CTL activity when challenged in vitro with both Qa-1 and H-Y, indicating that recognition of the helper determinant causes in vivo priming of CTL-P rather than generating helper activity that might activate unprimed CTL-P in vitro.
Whereas unprimed peripheral CTL-P require the presence of both Qa-1 (CTL) and H-Y (helper) determinants for successful in vivo priming, helper determinants were not required in vitro because primed CTL-P from B6.T1a(a) mice could be driven to CTL in vitro using sex-matched B6 stimulator cells.
The generation of anti-Qa-1(b) CTL is under immune response (Ir) gene control because F(1) mice, obtained by crossing responder A/J with nonresponder B6.T1a(a) animals, generated CTL to the Qa-1(b) alloantigen when presented on B6 spleen cells. Progeny testing of backcross mice further demonstrated that the Ir gene(s) is linked to the H-2 complex.
These data indicate that an H-2-linked Ir gene controls the recognition of helper determinants required for CTL priming in vivo. These helper determinants can be distinguished from CTL determinants and both must be recognized together for successful priming of CTL-P.
Contribution of antigen-presenting cell major histocompatibility complex gene products to the specificity of antigen-induced T cell activation
Authors: Heber-Katz E , Schwartz RH , Matis LA , Hannum C , Fairwell T , Appella E , Hansburg D 
Published: June 2004

Previous studies from our laboratory showed that B 10.A mice are high responders to pigeon cytochrome c fragment 81-104, whereas B 10.A(5R) mice are low responders. In the present studies, the C-terminal cyanogen bromide cleavage fragment and homologous synthetic peptides of tobacco horn worm moth cytochrome c were shown to be immunogenic in both B10.A and B10.A(5R) mice. These strains, however, showed different patterns of cross-reactivity when immune lymph node T cells were stimulated with cytochrome c fragments from other species. To examine the two patterns of responsiveness at a clonal level, cytochrome c fragment-specific T cell hybridomas were made and found to secrete interleukin 2 in response to antigen. The patterns of cross- reactivity of these B 10.A and B 10.A(5R) clones were similar to that seen in the whole lymph node population. Surprisingly, when these clones were tested for major histocompatibility complex (MHC)-restricted antigen recognition, they were all found to respond to antigen with both B10.A and B10.A(5R) antigen-presenting cells (APC). Furthermore, the cross-reactivity pattern appeared to be largely determined by the genotype of the APC, not the genotype of the T cell clone. That is, a given T cell clone displayed a different fine specificity when assayed with B10.A or B10.A(5R) APC. This observation indicates that the APC MHC gene product and antigen interact during the stimulation of the T cell response and that as a consequence the specificity of antigen-induced T cell activation is influenced by these MHC gene products.
(During the preparation of this manuscript it has come to our attention that results similar to our own, concerning the fine specificity of cytotoxic T cell clones, have been obtained by Dr. T. R. Hunig and Dr. M. J. Bevan, Massachusetts Institute of Technology, Boston, MA. T. R. Hunig and M. J. Bevan. 1981. Specificity of T-cell clones illustrates altered self hypothesis. Nature. 294:460.)