bluuebunny/crossref_metadata_2025 huggingface dataset:
The identification in adult bone marrow of pluripotent and restricted stem cells of the myeloid and lymphoid systems
Authors: Abramson S , Miller RG , Phillips RA
Published: June 2004

The precise relationship between the stem cells for the lymphoid system and those for the blood-forming system is unclear. While it is generally assumed that the hemopoietic stem cell, the spleen colony-forming unit (CFU-S), is also the stem cell for the lymphoid system, there is little evidence for this hypothesis. To investigate the stem cells in these two systems, we irradiated bone marrow cells to induce unique chromosome aberrations in the stem cell population and injected them at limiting dilution into stem cell-deficient recipients. Several months (between 3 and 11) were allowed for the injected cells to repopulate the hemopoietic system. At that time, the bone marrow, spleen, and thymus were examined for a high frequency of cells having the same unique chromosome aberration. The presence of such markers shows that the marker was induced in a cell with extensive proliferative capacity, i.e., a stem cell. In addition, the splenic lymphocytes were stimulated with phytohemagglutinin (PHA) or lipopolysaccharide (LPS) to search for unique chromosomes in dividing T and B cells, respectively. Finally, bone marrow cells were injected into secondary irradiated recipients to determine if the marker occurred in CFU-S and to determine whether or not the same tissue distributions of marked cells could be propogated by bone marrow cells in a second recipient. After examination of 28 primary recipients, it was possible to identify three unique patterns of stem cell regeneration. In one set of mice, a unique chromosome marker was observed in CFU-S and in PHA- and LPS-stimulated cultures. These mice provide direct evidence for a pluripotent stem cell in bone marrow. In addition, two restricted stem cells were identified by this analysis. In three recipients, abnormal karyotypes were found only in myeloid cells and not in B and T lymphocytes. These mice presumably received a marked stem cell restricted to differentiate only into myeloid progeny. In three other recipients, chromosome aberrations were found only in PHA-stimulated cells; CFU-S and cells from LPS cultures did not have cells with the unique chromosome. This pattern suggests that bone marrow contains cells committed to differentiation only into T lymphocytes. For each of the three types of stem cells, secondary recipients had the same cellular distribution of marked cells as the primary recipients. This observation provides further evidence that unique markers can be induced in both pluripotent and restricted stem cells.
Ontogeny of B-lymphocyte function. III. In vivo and in vitro studies on the ease of tolerance induction in B lymphocytes from fetal, neonatal, and adult mice
Authors: Szewczuk MR , Siskind GW
Published: June 2004

The ease of tolerance induction in B lymphocytes from fetal, neonatal, and adult mice was studied in vivo, in a cell transfer system, and in vitro. Three different tolerogens were used: ultracentrifuged BGG, DNP(6)-D-GL, and ultracentrifuged DNP(22)-BGG. Irradiated thymectomized mice were reconstituted with B cells from fetal or neonatal liver or adult spleen or bone marrow. The mice were injected with tolerogen 1 day later. They were given normal thymus cells and challenged with either BGG or DNP(44)-BGG between 4 and 14 days after tolerance induction. With BGG no difference in ease of B-cell tolerance induction was observed in mice reconstituted with B cells from 17-day fetal liver, neonatal liver, 8- day-old spleen, adult spleen, or adult bone marrow. B cells from 14-day fetal donors are relatively resistant to tolerance induction. In contrast, with DNP(6)-D-GL and DNP(22)-BGG B cells from neonatal donors were clearly more susceptible to tolerance induction than were B cells from adult donors. Comparable results were obtained in studies on tolerance induction in vitro. Neonatal B cells were more susceptible than adult B cells to tolerance induction upon culture with DNP(6)-D-GL or DNP(22)-BGG. However, neonatal and adult B cells were identical with respect to ease of tolerance induction in vitro with deaggregated BGG.

The results suggest that there are multiple mechanisms for B-cell tolerance induction. Immature B cells appear to be more susceptible to tolerance induction by some mechanisms but not by others. It is suggested that immature B cells are more susceptible to tolerance induction with moderately polyvalent antigens such as hapten-carrier conjugates. With antigens like BGG which do not haverepeated epitopes no difference between mature and fetal B cells in regard to ease of tolerance induction is observed. These observations raise questions about the importance of relative ease of tolerance induction in immature B cells as a mechanism controlling the normal induction of self tolerance.
On the occurrence of cytochrome P-450 and aryl hydrocarbon hydroxylase activity in rat brain.
Authors: Cohn J A , Alvares A P , Kappas A
Published: June 2004

The difference spectra of the carbon monoxide-complex of dithionite-reduced rat brain microsomes, compared with both reduced microsomes, alone, and the carbon monoxide-complex of oxidized microsomes, indicate the presence of small amounts of cytochrome P-450 in brain. As in liver, cytochrome P-450 in brain is degraded in vitro to its inactive form, cytochrome P-420 by methylmercury chloride. Aryl hydrocarbon hydroxylase activity is also present in rat brain microsomes and, at lower specific activity, in brain homogenates. This carcinogen metabolizing activity is increased four-fold in rats pretreated with 3-methylcholanthrene.
Maintenance of hemopoietic stem cells and production of differentiated progeny in allogeneic and semiallogeneic bone marrow chimeras in vitro.
Authors: Dexter T M , Moore M A , Sheridan A P
Published: June 2004

A culture system is described in which bone marrow-derived adherent cells can support prolonged proliferation and differentiation of genetically incompatible stem cells and precursor cells. The results suggest that the reactive cells responsible in vivo for host transplantation resistance and for graft-versus-host disease are selectively lost or inhibited in such cultures, which may provide a vehicle for studying some of the cellular mechanisms involved in transplantation resistance.
Human histocompatibility determinants and virus antigens: effect of measles virus infection on HLA expression.
Authors: Haspel M V , Pellegrino M A , Lampert P W , Oldstone M B
Published: June 2004

Histocompatibility antigens on the surface of human lymphoblastoid cells were quantified by a microadsorption technique. During the course of measles virus infection, no quantitative or qualitations in surface HLA antigens were observed. In contrast, infection with poliovirus type 1 or vesicular stomatitis virus, or treatment with puromycin (50 microgram/ml) resulted in a significant decrease in surface HLA. These experiments suggest that an inhibition of host protein synthesis rather than the insertion of virus-specificied antigens into the membrane results in a net decrease in amounts of this cell surface antigen. The HLA antigens also appear to be both functionally and structurally distinct from measles virus surface antigens. Pretreatment of cells with HLA-directed antibody did not prevent the infection of these cells by measles virus, thus HLA antigens appear unrelated to the measles virus receptor site on the plasma membrane. Electron microscopic studies revealed that measles virus maturation occurs at membrane sites devoid of demonstrable HLA. Furthermore, HLA antigens could not be detected on the surfaces of mature infectious virions.
Dengue viruses and mononuclear phagocytes. I. Infection enhancement by non-neutralizing antibody
Authors: Halstead SB , O'Rourke EJ
Published: June 2004

Cultured mononuclear peripheral blood leukocytes (PBL) from nonimmune human beings and monkeys are nonpermissive to dengue 2 virus (D2V) infection at multiplicities of infection of 0.001-0.1, but become permissive when non-neutralizing dengue antibody is added to medium. D2V infection occurred in PBL prepared from anti-coagulated but not from defibrinated plasma. Infection enhancement was produced by multiple lots of heterotypic anti-dengue raised in several mammalian species. Homotypic anti-dengue neutralized D2V at high concentrations but enhanced at low concentrations; enhancement end point in one serum was 1:320,000. The infection-enhancing factor was a noncytophilic antibody of the IgG class. D2V infection occurred in the absence of heat-labile complement components but did not occur when complexes were prepared with anti- dengue F(ab)(2). Treatment of PBL with several proteases increased permissiveness to D2V infection by immune complexes but not by virus alone. Two rhesus monkey serums collected 14 days after D2V infection contained an IgG antibody with high-titered enhancing activity but with no hemagglutination-inhibition or neutralizing activity. Virus-antibody complexes are irreversibly attached to PBL within 15 min and completely internalized in 60 min. There was considerable variation in cellular infection in different experiments, however, maximum virus yields usually exceeded 1,000 plaque-forming units per 1 x 10(6) PBL occurring between 2 and 4 days in culture. In vitro antibody-dependent infection of PBL provides a possible model for study of pathogenetic mechanisms in infants with dengue shock syndrome who passively acquire maternal anti-dengue IgG.
Activation of the alternative complement pathway with rabbit erythrocytes by circumvention of the regulatory action of endogenous control proteins
Authors: Fearon DT , Austen KF
Published: June 2004

Cleavage of C3 by the alternative complement pathway occurs in at least two distinct phases: continuous low grade generation of C3b by the interaction of native C3, B, D, and P, and subsequent amplified cleavage of C3 by the interaction of C3b, B, D, and P which forms the amplification convertase, P,C3b,Bb. Transition to C3b-dependent amplification is necessary to achieve substantial C3 cleavage and is normally limited by the combined action of C3b inactivator (C3bINA) and βlH. An activator of the alternative pathway, such as rabbit erythrocytes (E(r)), provides sites that protect bound C3b and P,C3b,Bb from the action of these regulatory proteins and permits C3b deposited by the low grade fluid phase reaction to assemble a membrane-associated amplification convertase which can deposit additional protected C3b.

Under conditions in which the control proteins, C3bINA and β1H, almost completely inactivated C3b bound to sheep erythrocytes (E(s)), which does not activate the alternative pathway, the function of C3b bound to E(r) was diminished by less than one-fifth. Further, the P- stabilized amplification convertase on E(r) was 10-fold less sensitive to β1H-mediated decay-dissociation than the convertase on E(s). The addition of E(r) to a regulated mixture of purified C3, B, D, P, C3bINA, and β1H resulted in amplified inactivation of C3 and B by formation of the amplification convertase on E(r) as indicated by its lysis with subsequent exposure to C3-C9. In contrast, E(s) did not advance the low grade fluid phase inactivation of C3 and B to amplified inactivation and the cell was not converted to an intermediate susceptible to lysis by C3- C9. Since E(r) and E(s) did not differ in their inefficient fixation of C3b generated during an unregulated fluid phase reaction, the activating capacity of E(r) must reside in its protection of bound C3b and P, C3b,Bb from the regulatory proteins rather than in enhanced capacity to bind C3b from the fluid phase. When the reaction is limited to low grade fluid phase turnover, introduction of E(r) but not E(s) results in a 100-fold increase in the deposition of C3b, indicating that surface-dependent activation of the alternative pathway is characterized by efficient deposition of C3b on the initiating surface. Thus, the activating surfaces advance the interaction of the alternative pathway proteins to the amplification phase because of the selective inability of the regulatory proteins to deal with their substrates when deposited on these surfaces and results in a specificity that is not necessarily dependent on adaptive immunity.
Preleukemic expression of TL antigens in x-irradiated C57BL/6 mice.
Authors: Stockert E , Old L J
Published: June 2004

Anomalous appearance of TL (thymus-leukemia) antigens is a characteristic feature of radiation-induced leukemias of C57bl/6 mice. We now report that thymocytes of irradiated C57BL/6 mice express TL antigens long before the development of overt leukemia. Thus, TL is a marker for preleukemic changes occurring during radiation leukemogenesis. Low levels of murine leukemia virus (MuLV)-related antigens are also detected on preleukemic thymocytes. Comparative tests on individual mice show no direct correlation between TL and MuLV antigen expression.
Evidence for differences in erythrocyte surface receptors for the malarial parasites, Plasmodium falciparum and Plasmodium knowlesi.
Authors: Miller L H , Haynes J D , McAuliffe F M , Shiroishi T , Durocher J R , McGinniss M H
Published: June 2004

Human erythrocytes lacking various blood group determinants were susceptible to invasion by Plasmodium falciparum including Duffy-negative erythrocytes that are refractory to invasion by Plasmodium knowlesi. Erythrocytes treated with trypsin or neuraminidase had reduced susceptibility of P. falciparum and normal susceptibility to P. knowlesi. Chymotrypsin treatment (0.1 mg/ml) blocked invasion only by P. knowlesi. The differential effect of enzymatic cleavage of determinats from the erythrocyte surface on invasion by these parasites suggests that P. falciparum and P. knowlesi interact with different determinants on the erythrocyte surface.
Novel idiotypic and antigen-binding characteristics in two anti-dinitrophenyl monoclonal antibodies.
Authors: Sigal N H
Published: June 2004

Monoclonal anti-dinitrophenyl antibodies generated in the splenic focus system from B cells of adult BALB/c mice were studied for the presence or absence of murine anti-T15 (M anti-T15) reactivity and for their ability to bind phosphorylcholine (PC). Two foci of the 680 clones analyzed bound PC, and one of these antibodies reacted with M anti-T15 and anti-Fab on a 1:1 weight basis. The discovery of a clonotype reactive with M anti-15 but not with rabbit anti-T15 (R anti-T15) serum, the converse of the R anti-T15+, M anti-T15- clonotype identified in the PC-specific repertoire, points to the novel idiotypic relationships which may be found among homogeneous antibodies binding diverse antigens. The R anti-T15-, M anti-T15+ clonotype may represent a distinct set of hypervariable region sequences inserted into the T15 framework or may be a somatic variant of the T15 germ-line sequence. In addition, the maximum frequency with which this clonotype occurs within the B-cell pool is estimated.
Molecular internalization of a region of myelin basic protein
Authors: Whitaker JN , Chou CHJ , Chou FCH , Kibler RF
Published: June 2004

The conformation of myelin encephalitogenic or basic protein (BP) was investigated with a double-antibody radioimmunoassay by studying the reaction of BP or its fragments with antibodies produced in two rabbits against peptide 43-88 linked to rabbit serum albumin. Both antisera reacted well with peptide 43-88 but showed little or no reaction with BP. Absorption of these antisera with a BP-immunoadsorbent did not remove the antibody activity against peptide 43-88. Within the region of peptide 43- 88 it was shown that peptides 68-88 and 79-88 gave an equivalent or better reaction than peptide 43-88, whereas peptides 43-67 and 64-73 had very little reactivity. In the BP fragments containing region 43-88, peptide 1-88 showed the best reactivity, peptide 20-166 showed minimal reactivity, while peptide 1-115 showed none.

These data document the internal position of at least a portion of peptide 43-88 and all of residues 79-88 in the BP molecule. The much greater reactivity of peptide 1-88 as compared to peptide 1-115 suggests that the region or a portion of the region of BP containing residues 89- 115 participates in the conformational alignment of BP restricting access to peptide 79-88. After absorption with BP, neither of the antisera prepared to peptide 43-88 reacted with PNS myelin in fixed tissue sections but continued to react with CNS myelin in similarly treated sections. The present findings demonstrate the need to consider the role of shielded antigenic determinants in the investigation of antigens or of immune responses.
Streptococcal-induced cell-mediated-immune destruction of cardiac myofibers in vitro.
Authors: Yang L C , Soprey P R , Wittner M K , Fox E N
Published: June 2004

We have demonstrated that T lymphocytes from the spleens of adult guinea pigs sensitized to group A streptococcal antigens are cytotoxic for cultured fetal guinea pig heart cells. Lymphocyte cytotoxicity, measured by 51Cr release from target cells, was stimulated by sensitization in vivo with group A whole cells, cell walls, and purified protoplast membranes emulsified with complete Freund's adjuvant (CFA). Sensitization with group C streptococcal antigens in CFA or CFA alone produced lymphocytes with little or no specific cytotoxic activity. Target cells of cultured fetal skeletal muscle, liver, or skin were relatively refractory to effector cell cytotoxicity. The presence of antigenic determinants on the membranes of cultured myofibers, cross-reacting with group A streptococcal cellular antigens, was confirmed by immunofluorescence. These data are discussed in terms of a model for poststreptococcal rheumatic myocarditis in which cell-mediated autoimmune mechanisms may participate.
Sharing of Ia antigens between species. I. Detection of Ia specificities shared by rats and mice.
Authors: Sachs D H , Humphrey G W , Lunney J K
Published: June 2004

A mouse anti-rat xenogeneic antiserum, B10.D2 anti-BN, has been found to react with a subpopulation of lymphoid cells of certain mouse strains. The corresponding alloantiserum, B10.D2 anti-B10.BR, reacted in analogous fashion with lymphoid cells of BN rats. In the case of the cross-reaction on mouse cells, mapping studies indicated that at least part of the reactivity was with the product of gene(s) determined by the I-A subregion of the H-2 complex. Chemical isolation studies with radiolabeled cell surface preparations indicated that the antigens detected in both mouse and rat had mol wt characteristic of Ia antigens (35,000 and 28,000 dalton molecules). Testing of fractionated spleen cell populations revealed that the cross-reactive antigens were expressed predominatly on B cells, but that a subpopulation of T cells were also reactive. Wider strain and species distribution studies are in progress to determine the extent of such Ia cross-reactions between species and to further assess the practical and theoretical importance of such cross-reactions.
Evolution of an idiotypic determinant: anti-Val.
Authors: Karol R A , Reichlin M , Noble R W
Published: June 2004

An antibody population which reacts only with human sickle cell hemoglobin (HbS) and not with normal human hemoglobin, has been isolated from goat, sheep, and guinea pig antisera. These antibody populations termed anti-Val (Val), isolated from an individual goat (no. 6) and sheep (no. 26) have been used to elicit anti-idiotypic responses in rabbits. These anti-idiotypic sera were used to study the idiotypic cross-reactions between the goat and sheep anti-Val. Strong cross-reactions were present using either Ra anti-goat anti-Val or Ra anti-sheep anti-Val. Guinea pig anti-Val did not cross-react with these anti-idiotypic sera. Binding of HbS to the anti-Val of the goat and sheep could be blocked by the anti-idiotypic sera, but the binding of HbS to the guinea pig anti-Val could not. These data demonstrate idiotypic cross-reactivity between two closely related species.
In vitro generation of tumor-specific cytotoxic lymphocytes. Secondary allogeneic mixed tumor lymphocyte culture of normal murine spleen cells
Authors: Gillis S , Smith KA
Published: June 2004

In vivo or in vitro immunity to murine leukemia virus (MuLV)-induced leukemia cells which do not effectively produce virus, has been difficult to demonstrate. Because immunizations with allogeneic murine leukemia cells have been used to confer syngeneic tumor immunity to virus- producing cells, we attempted to generate lymphocytes, cytotoxic to syngeneic nonproducer leukemia cells, by stimulating normal murine spleen cells with allogeneic nonproducer leukemia cells in mixed tumor lymphocyte culture (MTLC) reactions in vitro. Secondary allogeneic MTLC of normal C57BL/6 or DBA/2 spleen cells effectively produced syngeneic tumor-specific cytotoxic lymphocytes. Target cells lysed in lymphocyte- mediated cytolysis (LMC) assays, included both Friend and Rauscher virus- induced syngeneic murine leukemia cells and chemically-induced hematopoietic tumor cells. Syngeneic tumor cells were lysed regardless of whether they produced infectious MuLV or expressed viral antigens gp-71, p-30, or p-12 at the cell surface. Syngeneic normal cells (thymus, lymph node, or Concanavalin A-stimulated spleen cells) used as targets in LMC assays were uneffected by lymphocytes harvested from secondary allogeneic MTLC. Several other in vitro culture treatments including secondary syngeneic MTLC and repetitive mixed lymphocyte culture stimulations were incapable of generating tumor-specific cytotoxic lymphocytes.

Based upon these results, we propose that secondary MTLC stimulation of normal spleen cells with allogeneic nonproducer leukemia cells selects for the proliferation of two subpopulations of antigen-specific cytotoxic lymphocytes. The population capable of effecting syngeneic tumor cell lysis is directed against tumor-associated cell surface antigens which may be distinct from viral structural proteins or glycoproteins. The growth of these tumor-specific cytotoxic lymphocytes may be enhanced by a soluble allogeneic effect factor produced by the proliferation of the second subpopulation of lymphocytes generated in repetitive allogeneic MTLC, namely those lymphocytes with specificities directed against differing histocompatibility antigens.
Suppression of in vitro Epstein-Barr virus infection. A new role for adult human T lymphocytes.
Authors: Thorley-Lawson D A , Chess L , Strominger J L
Published: June 2004

Studies have been performed on in vitro infection by Epstein-Barr virus (EBV) of subpopulations of human lymphocytes. B cells of adult peripheral or fetal cord blood transform with equal efficiency, whether assayed by DNA synthesis induction or by outgrowth of transformed lymphocytes. In contrast, unfractionated adult lymphocytes transform much less efficiently than those from fetal cord. Reconstitution experiments of different cell preparations indicated that this difference was due to a suppression of B-cell proliferation by adult Ig-negative lymphocytes which fetal Ig-negative lymphocytes were unable to perform. Separation of Ig-negative lymphocytes into various subpopulations revealed that the suppression was performed by T cells. Macrophages and null cells play little or no role in suppression. The relevance of this phenomenon to infection and recovery from EBV infection during and after infectious mononucleosis is discussed.
C6: synthesis by the liver in vivo.
Authors: Hobart M J , Lachmann P J , Calne R Y
Published: June 2004

The allotype of the sixth component of complement was determined in a patient before and after liver transplantation. The C6 phenotype changed from A before transplantation to B (the donor phenotype) within 10 days of the transplant and remained wholly of the donor phenotype at 17 wk. This demonstrates that the liver is the exclusive or predominant site of C6 synthesis in vivo in man.
Induction and properties of cytoplasmic factor(s) which enhance nuclear nonhistone protein phosphorylation in lymphocytes stimulated by anti-Ig.
Authors: Nishizawa Y , Kishimoto T , Kikutani H , Yamamura Y
Published: June 2004

An increased in vitro phosphorylation of nonhistone nuclear proteins (NHP) was observed in the nuclei isolated from rabbit lymphocytes which had been stimulated with anti-Ig for 4 h. No concomitant increase of phosphorylation in histones or 0.14 M NaCl-soluble proteins was observed. The increase of in vitro phosphorylation of NHP was also observed in the nuclei isolated from nonstimulated cells when these nuclei were preincubated for 2 h with cell-free extracts from anti-Ig-stimulated cells. The active substance in cell-free extracts was maximally induced when lymphocytes were stimulated with anti-Ig for 2 h. The induction of an increased phosphorylation of NHP in nonstimulated nuclei with the cell-free extracts was not due to decrease of the adenosine triphosphate pool in the extracts from anti-Ig-stimulated cells. The active substance in cell-free extracts was not NHP-protein kinase itself, but it probably activated NHP-protein kinase in quiescent nuclei. The active substance was nondialyzable and probably protein. It was resistant against heating at 56 degrees C for 30 min, but the activity was completely destroyed by heating at 90 degrees C for 30 min. The active substance may be responsible for the transduction of the membrane-mediated signals given through Ig receptors to nuclei.
Suppression of in vitro cytotoxic response by macrophages due to induced arginase.
Authors: Kung J T , Brooks S B , Jakway J P , Leonard L L , Talmage D W
Published: June 2004

Arginine was found to be completely depleted from cell-free supernates of mixed leukocyte cultures suppressed by the addition of excess macrophages. Partial reversal of macrophage-mediated suppression was accomplished by daily addition of a cocktail containing arginine and nonamino acid nutrients. Complete reversal of the suppression was accomplished by the addition of arginine and glucose to the medium and the nonadherent cells after their separation from the adherent macrophages. A marked increase in the enzyme arginase was found in macrophages that had been cultured 24 h in vitro in Eagle's minimum essential medium plus 10% fetal calf serum, in peritoneal cells activated by prior injection of thioglycollate, and in one spleen activated by a graft vs. host reaction.
Inhibition of T-antigen-binding cells by idiotypic antisera.
Authors: Prange C A , Fiedler J , Nitecki D E , Bellone C J
Published: June 2004

Shared idiotypy between B- and T-cell receptors specific for the antigen L-tyrosine-p-azophenyltrimethylammonium [tyr(TMA)] was studied in an antigen-binding assay using idiotypic antisera. These idiotypic reagents were prepared by inoculation of rabbits with purified anti-tyr(TMA) antibody raised in strain 13 guinea pigs. The antisera blocked 78-83% of the antigen-binding T cells (T-ABC) and 50-55% of the antigen-binding B cells (B-ABC) from tyr(TMA)-immune strain 13 and outbred lymph node cells (LNC). An excess of normal guinea pig Ig in the ABC assay did not affect the ability of the idiotypic antisera to block T- and B-ABC. Nylon wool-passed tyr(TMA)-immune LNC were trypsin treated resulting in a 75% loss of T-ABC. The trypsin-treated population was then cultured for 16 h which resulted in a return of T-ABC to 92% of pretrypsin values. 77% of these regenerated T-ABC could be blocked with idiotypic antisera. Specificity of the idiotypic antisera was tested in L-tyrosine-p-azobenzenearsonate-immune guinea pig LNC. Neither T- nor B-ABC were blocked in this heterologous system. Further blocking experiments were performed to characterize the nature of the T-ABC receptor. A variety of anti-Ig reagents, some of which block B-ABC, do not inhibit T-ABC suggesting that variable regions on T cells are not linked to Ig Constant regions.
Release from maternally-induced allotypic suppression in rabbit by Nocardia water-soluble mitogen.
Authors: Bona C , Cazenave P A
Published: June 2004

The in vitro synthesis of allotypes of b4/b5 offspring obtained from b4/b4 mothers immunized against paternal allotype b5/b5 was studied in comparison to similar offspring that had escaped from suppression and normal heterozygous b4/b5 rabbits. Nocardia water-soluble mitogen-a rabbit B-cell mitogen which is known to induce the differentiation of small lymphocytes into plasma cells and polyclonal activation of Ig, was able to break in vitro the allotypic suppression induced in vivo.
Hemagglutinin-specific cytotoxic T-cell response during influenza infection.
Authors: Ennis F A , Martin W J , Verbonitz M W
Published: June 2004

Specific cytotoxic thymus-derived (T) lymphocytes were detected in the cervical lymph nodes and spleen during influenza infection of mice. The cytotoxic T cells can distinguish target cells infected with different influenza A subtypes. Infection with parent viruses and their recombinant progeny possessing the hemagglutinin of one parent and the neuraminidase of the other demonstrated that significant cytotoxicity occurred only when the hemagglutinin of the immunizing viruses was the same as that of the virus used to infect the target cell. In addition to this specific cytotoxic response to the major surface antigen, a cross-reactive response could be detected when the relatively nonpermissive L cell was used as the target cell. These results indicate there is a specific cytotoxic T-cell response to the surface hemagglutinin, and a cross-reactive cytotoxic response, not directed to the hemagglutinin, during influenza infection. The cytotoxic T-cell response specific for the hemagglutinin antigen may play an important role in in vivo immunity to influenza.
Antigenic differences in nuclear proteins of normal liver and hepatoma
Authors: Ruoslahti E , Engvall E , Jalanko H , Comings DE
Published: June 2004

A nuclear antigen was detected in the mouse liver nonhistone protein fraction by using antibodies to whole liver cells. The antigen was purified to homogeneity from perchloric acid extracts of liver tissue. It gave a single band corresponding to tool wt 21,000 in sodium dodecyl sulfate gel electrophoresis. Amino acid and carbohydrate analysis showed predominance of the acidic amino acids, lack of proline, and absence of carbohydrate.

Immunofluorescence staining of liver sections confirmed the nuclear localization of the antigen. Its tissue distribution was studied by using radioimmunoassay. Of the various tissues extracted for analysis, the liver contained the highest amounts of the antigen, about 1 μg/mg of solubilized liver protein. Other tissues examined showed 2-4 percent of the amount of antigen present in the liver. Two transplantable hepatomas in C3H/HeJ and C57L/J mice, respectively, and three spontaneous C3H hepatomas showed greatly decreased levels of the antigen compared to normal liver. The amount of antigen in hepatomas varied from nondetectable to 2 percent of the amount of antigen found in the livers of the mice. The antigen was also found in the blood.

The antigen was found in high concentrations (up to 13 mg/ml) in the urine of normal mice. This suggests identity with the previously known mouse urinary protein (MUP). In addition to the extremely high urinary output, the properties found to be shared by MUP and the nuclear antigen included similar serum concentrations (2-60 μg/ml), a sex difference with lower values in females, same molecular size as determined by gel filtration, and immunological identity. The nuclear localization of MUP and its disappearance from hepatomas suggest that it may have an important regulatory function.
Specificity of cytotoxic effector cells directed against trinitrobenzene sulfonate-modified syngeneic cells. Failure to recognize cell surface- bound trinitrophenyl dextran
Authors: Henkart PA , Schmitt-Verhulst A , Shearer GM
Published: June 2004

Mouse splenic lymphocytes and lymphoid tumor cells were modified with the trinitrophenyl (TNP) group either by treatment with trinitrobenzene sulfonate (TNBS) (which covalently modifies cell surface proteins) or with TNP stearoyl dextran (TSD) (which binds to the cell by noncovalent forces). These cell preparations were compared for their ability to: (a) sensitive syngeneic splenic lymphocytes leading to the generation of cytotoxic effector cells; (b) serve as lysable targets in a 4-h(51)Cr- release assay for effector cells generated in (a); and (c) act as blocking cells in the lysis of TNBS-medified targets lysed by TNP self effector cells generated in (a). In none of these three experimental systems did TSD-medified syngeneic spleen or H-2-matched tumor cells act either as a sensitizing immunogen or as a target antigen, despite the demonstration that quantitatively equivalent mounts of TNP were exposed on the cell surface in the TNBS- and TSD-modified cells. In contrast, TNBS-modified spleen cells sensitized syngeneic lymphocytes to generate effectors against TNBS-modified syageneic targets. Furthermore, TNBS- modified, H-2-matched cells served as specific lysable targets and as inhibiting cells for such effectors. These results indicate that the manner in which TNP is associated with the cell surface is important in the immunogenicity and antigenicity of hapten-modified syngeneic stimulating cells in generating H-2-associated cell-mediated lympholysis (CML) reactions. These findings raise the possibility that a covalent or at least a stable linkage with cell surface proteins (possibly H-2- controlled products) is important for immunological function. Furthermore, these observations do not favor the dual receptor model for H-2-restricted syngeneic CML if it is assumed in such a model that one receptor is specific for the TNP moiety and the second for unmodified self major histocompatibility products.
Induction of specific immune unresponsiveness using purified mixed leukocyte culture-activated T lymphoblasts as autoimmunogen. I. Demonstration of general validity as to species and histocompatibility barriers.
Authors: Andersson L C , Aguet M , Wight E , Andersson R , Binz H , Wigzell H
Published: June 2004

Normal immunocompetent T lymphocytes can be induced into specific proliferation if confronted with the relevant alloantigen in vitro. Such mixed leuko-cyteculture-activated T lymphoblasts carring idiotypic receptors on their surface can be purified using velocity sedimentation and serve as immunogen if administered in adjuvant to the autologous host. Autoblast immunization can be shown to lead to specific, long-lasting unresponsiveness against the relevant alloantigens, while leaving reactivity against third-party antigens intact. When tested as to general validity, it could be shown to function in all species analyzed (mouse, rat, and guinea pig) as well as across both major and minor histocompatibility barriers. No negative side effects have been noted so far. It would thus seem clear that autoblast immunization using the above described scheme may serve as a general tool in inducing long-lasting, specific unresponsiveness in any species and across any histocompatibility barrier.
Inability of mice with a defect in B-lymphocyte maturation to respond to phosphorycholine on immunogenic carriers.
Authors: Mond J J , Lieberman R , Inman J K , Mosier D E , Paul W E
Published: June 2004

Mice with the CBA/N defect are unresponsive to the hapten phosphorylcholine (PC) even when presented on a variety of immunogenic carriers. Since these mice have the variable region gene for PC, their inability to respond may reflect deletion or suppression of the line of B lymphocytes which is responsible for the anti-PC response.
Genetic control of lymphocyte activation: lack of response to low doses of concanavalin A in lipopolysaccharide-nonresponder mice
Authors: Bick PH , Persson U , Smith E , Moller E , Hammarstrom L
Published: June 2004

C3H/HeJ mice do not respond to the polyclonal B-cell activator lipopolysaccharide (LPS) from Escherichia coli; this was first described by Sultzer who observed that mice of this strain did not respond to an intraperitoneal (i.p.) injection of LPS as measured by the accumulation of leukocytes in the peritoneal cavity. Neither were C3H/HeJ mice as susceptible to LPS toxcitiy (1). It was later reported that LPS-induced mitogenesis (2,3), adjuvanticity (4), and the appearance of Ia antigens on B lymphocytes as induced by LPS, (5) was also absent in C3H/HeJ mice. However, lymphocytes from these mice respond normally to the polyclonal B-cell activators purified protein derivative of tuberculin (2,6) and dextran sulfate and have also been reported to respond normally to concanavalin A (Con A) (2). Furthermore, the immune responses to sheep erythrocytes (7) and soluble thymus-dependent antigens (4) are normal in C3H/HeJ mice. Unresponsiveness to LPS in C3H/HeJ mice has been found to Be due to a defect in a single gene or a set of linked genes (3,8) which has been mapped between the major urinary protein locus and the locus coding for polysyndactyly on chromosome 4. (1)

We have reported that injection of LPS into mice of an LPS-responsive strain causes a shift in the Con A dose-response curve of cultured spleen cells, suppressing the low does response (9). Therefore, we tested the Con A proliferative response in cultures of normal or LPS-activated spleen cells from LPS-responder (C3H/Tif) and LPS-nonresponder (C3H/HeJ) mice. We report here that C3H/HeJ spleen cells respond poorly to low concentrations of Con A (0.05-0.1 μg/ml). Injection of LPS 2 days before culture inhibits the response to low doses of Con A in cultures of C3H/Tif spleen cells but has no inhibitory effect on the dose response profile of C3H/HeJ spleen cells. Furthermore, the low dose Con A response of spleen cells is dependent upon the presence of an Ia-positive cell. (2) The role of Ia-positive cells in the Con A response of C3H/Tif and C3H/HeJ spleen cells is described.
Localization of amyloid-related serum protein SAA-like material to intermediate (10 nm) filaments of cultured human embryonal fibroblasts.
Authors: Linder E , Lehto V P , Virtanen I , Stenman S , Natvig J B
Published: June 2004

Further studies are presented on the intracellular localization of the amyloid-related serum protein SAA previously shown to be produced by embryonal fibroblasts. In cultured embryonal fibroblasts, the fine fibrillar cytoplasmic immunofluorescence obtained by anti-SAA was distinguished from that of microfilaments and microtubules. By using electron microscopy and cells treated with drugs known to specifically alter intracellular fibrils, SAA was localized to 10-nm intermediate size filaments. These filaments form characteristic perinuclear bundles upon treatment with drugs such as demecolcine or vinblastine which disrupt micotubules. The results indicate that SAA is a constituent of the intracellular cytoskeleton.
Immunosuppressive factor(s) specific for L-glutamic acid50-L-tyrosine50 (GT). III. Generation of suppressor T cells by a suppressive extract derived from GT-primed lymphoid cells.
Authors: Waltenbaugh C , Thèze J , Kapp J A , Benacerraf B
Published: June 2004

Injection of mice with L-glutamic acid50-L-tyrosine50 (GT)- or L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT)-specific suppressor T-cell factor (GT-TsF or GAT-TsF) up to 5 wk before antigenic challenge challenge suppresses GT-methylated bovine serum albumin (MBSA) and GAT-MBSA plaque-forming cells responses. T suppressor cells are responsible for the suppression induced by the suppressive extract as demonstrated by adoptive transfer and sensitivity to anti-Thy-1 and complement treatment. We conclude that suppressive extract induces specific suppressor T cells. The material responsible for generation of suppressor T cells is a product of the I subregion of the H-2 complex. We have excluded that suppressive quantities of antigens are present in the extract. A/J mice, which can neither be suppressed by GT nor make GT-TsF can be suppressed by BALB/c GT-tsf. Spleen cells from BALB/c GT TsF-primed A/J mice can adoptively transfer suppression to normal syngeneic recipients. A/J mice appear to be genetically defective in cells involved in factor production. These results are discussed in the light of a two-step model for induction of antigen-specific suppressor cells.
Isolation and characterization of murine cell surface components. I. Purification of milligram quantities of Thy-1.1
Authors: Zwerner RK , Barstad PA , Acton RT
Published: June 2004

The Thy-l.1 molecule was isolated from the BW5147 murine lymphoblastoid cell line. The initial step in purification was the preparation of a crude plasma membrane fraction followed by acetone precipitation. The acetone pellet was solubilized using deoxycholate (DOC) and Thy-1.1 was purified by use of a Lens culinaris lectin affinity column and an AcA-34 gel filtration column. The purified glycoprotein with Thy-1.1 activity had a mol wt of approximately 25,000 daltons. The isolation of this molecule was effected by detecting Thy-I activity utilizing rabbit anti- mouse brain serum tested on rat thymocytes. Congenic anti-Thy-l.1 serum was ineffective in detecting Thy-l.1 after DOC solubilization. An antiserum prepared in rabbits to the purified Thy-1.1 was found to be cytotoxic to mouse and rat thymocytes. The cytotoxic activity of this antisera could be completely absorbed with AKR/Jax brain and thymus but was not absorbed by liver. In addition, AKR/Jax thymocytes totally absorbed all cytotoxic activity of the rabbit anti-purified Thy-1 serum for BW5147 cells suggesting that the cell line shares identical specificities with normal thymocytes. The purified Thy-1.1 molecule was able to totally absorb the cytotoxic activity of mouse congenic anti-Thy-1. These studies serve as a model for the isolation of other murine lymphoid cell surface components in quantities for detailed structural and functional analysis.
Neutralization of reovirus: the gene responsible for the neutralization antigen.
Authors: Weiner H L , Fields B N
Published: June 2004

The S1 genome segment of reovirus is linked to type specificity as determined by neutralization antibody. This gene segment codes for a minor outer capsid polypeptide (sigma1). Therefore, sigma1 is the peptide responsible for induction of neutralization antibody and confers type specificity. This biologic property of reovirus was defined using hybrid recombinants clones between reovirus types 1 and 3 and 2 and 3.
Plasma cell immunoglobulin secretion. Arrest is accompanied by alterations the golgi complex
Authors: Tartakoff AM , Vassali P , Detraz M
Published: June 2004

Conditions influencing Ig secretion by plasma cells have been studied with suspensions of murine plasma cells and myeloma cells by determining the release of (3)H-Ig after a pulse of biosynthetic labeling with L- [4,5-(3)H]-leucine. Ig secretion is insensitive to a variety of hormones, mediators, cyclic nucleotide derivatives, extracellular calcium depletion, and agents acting on mierotubules or microfilaments; i.e., to a number of factors which are involved in the regulation of secretion by cells with a storage compartment. On the other hand, Ig secretion is markedly inhibited by conditions which (a) lower intracellular calcium levels (ionophore A 23187 in Ca(++)-free medium), (b) induce partial sodium/potassium equilibration (the ionophores monensin and nigericin and, in the case of myeloma cells, ouabain and incubation in K(+)-free medium) or (c) uncouple oxidative phosphorylation. The first two situations are accompanied by striking alterations of the ultrastructural appearance of the Golgi complex, different in each case. These ultrastructural observations, together with autoradiographic experiments after a short pulse with L-[4,5-(3)H]-leucine, have led to the following hypothesis: (a) under Ca(++) depletion (3)H-Ig passes to Golgi vesicles but these vesicles are incapable of fusion or migration and therefore accumulate in exaggerated numbers in the Golgi area; (b) under partial Na(+)/K(+) equilibration, (3)H-Ig passes to Golgi vesicles which have an exaggerated tendency to fuse with other Golgi elements, thereby generating large vacuoles which store increasing amounts of Ig; (c) under energy block, multiple membrane fission and fusion events are inhibited and there is therefore, little intracellular transport of (3)H-Ig or alteration of cell ultrastructure.
H-2 effects on cell-cell interactions in the response to single non-H-2 alloantigens. I. Donor H-2D region control of H-7.1-immunogenicity and lack of restriction in vivo.
Authors: Wettstein P J , Haughton G , Frelinger J A
Published: June 2004

Genes in the H-2 complex regulate the relative immunogenicity of the H-7.1 histocompatibility alloantigen, as measured by survival times of H-7.1-incompatible skin grafts in vivo. The gene controlling relative rejectability of H-7.1-incompatible grafts has been mapped to the H-2D region. H-7.1-incompatible skin grafts donated by H-2Db donors were rejected significantly more rapidly by H-2a/H-2b heterozygous recipients than similar H-7.1-incompatible grafts donated by H-2Dd donors. Further, there was absolutely no evidence of H-2 restriction in cytotoxic effector activity. In vivo cross-priming, as indicated by accelerated secondary graft rejection, was extensive. The efficiency of cross-priming was dependent upon the primary and secondary graft donor H-2 haplotypes.
Preparative purification of the rat mast cell chymase. Characterization and Interaction with granule components
Authors: Yurt R , Austen KF
Published: June 2004

The rat mast cell granule chymotrypsinlike enzyme was purified to homogeneity from 1 M NaCl solubilized membrane and granule-rich fractions of concentrated rat peritoneal mast cells by a preparative technique utilizing chromatography on Dowex 1, filtration on Sephadex G-75, and affinity chromatography with D-tryptophan methyl ester. Acid disk gel electrophoresis of the purified chymase disclosed a single stained band with activity being eluted from a replicate sliced gel in the same region. SDS-polyacrylamide gel electrophoresis of purified protein gave a single stained band that did not change in position with reduction and alkylation. Mast cell chymase is thus a cationic protein of 25,000 mol wt composed of a single polypeptide chain. The apparent K(m) of the chymase for BTEE was 1.5 x 10(-3) M and the V(max) was 67.8 μmol/min per mg. The enzyme was inhibited by TPCK and not by TLCK. The chymase complexed with native macromolecular rat mast cell heparin in molar ratios of 12:1 and 16:1, and complete heparin uptake occurred at a 40:1 ratio of chymase to heparin. Chymase activity was partially masked by combination with heparin in the isolated granule or experimental chymase-heparin complex, and soluble purified chymase was inhibited by concentrations of 5-HT comparable to those present in mast cells. It is therefore possible that the active site of chymase in the mast cell granule is largely masked by the combined effects of macromolecular heparin and 5-HT.
Expression of a new cell surface antigen on activated murine macrophages.
Authors: Kaplan A M , Mohanakumar T
Published: June 2004

A macrophage cell-surface antigen associated with pyran and Corynebacterium parvum-activated macrophages and P388D1 cells but not detectable on normal or glycogen and thioglycollate-elicited murine macrophages has been described. The antigen was demonstrated both by complement-mediated cytotoxicity and immunofluorescence, using an appropriately absorbed rabbit antiserum to P388D1. This antiserum should enable the characterization of activated macrophage cell populations on an individual cell basis and should be a useful probe to study the interactions of macrophages with tumor cells and the relationship of activation to cell-surface changes.