bluuebunny/crossref_metadata_2025 huggingface dataset:
Tolerance induction during ontogeny. I. Presence of active suppression in mice rendered tolerant to human gamma-globulin in utero correlates with the breakdown of the tolerant state.
Authors: Waters C A , Pilarski L M , Wegmann T G , Diener E
Published: June 2004

A specific state of T- and B-cell tolerance to human gamma-globulin (HGG) was induced in utero by intravenous administration of the deaggregated antigen to pregnant BALB/cCr mice. Tolerance persisted in the offspring until the 12th-wk of age and then began to gradually disappear. Suppressor cells could only be found when responsiveness to HGG ultimately appeared in the in utero-treated animals but not when they were completely unresponsives. In contrast, HGG-specific suppressors found in animals made unresponsive to HGG as adults appear to be associated with either the establishment and/or maintenance of the unresponsive state. To the extent that these experiments are consistent with natural self-tolerance to a serum protein, we conclude that active suppression is not a prerequisite from maintenance of unresponsiveness to self.
Cellular and genetic control of antibody responses. V. Helper T-cell recognition of H-2 determinants on accessory cells but not B cells.
Authors: Singer A , Hathcock K S , Hodes R J
Published: June 2004

Requirements for helper T-cell recognition of H-2 determinants expressed on adherent accessory cells and on B cells was individually assessed in the anti-hapten PFC responses to TNP-KLH. Complicating allogeneic effects were minimized or avoided by the use of helper T cells from normal F1 hybrids, parent leads to F1 chimeras, and F1 leads to parent chimeras. The results of both in vitro and in vivo experiments demonstrated that: (a) helper T cells are not required to recognize the identical H-2 determinants on both accessory cells and B cells; (b) helper T cells are required to recognize K or I-A region-encoded determinants expressed on accessory cells; (c) no requirement was observed in vitro or in vivo for helper T-cell recognition of B-cell-expressed H-2 determinants; and (d) no requirement was observed for H-2 homology between accessory cells and B cells. The absence of required helper T-cell recognition of the identical H-2 determinants on both accessory cells and B cells was demonstrated in two ways: (a) naive of KLH-primed (A x B)F1 hybrid helper T cells collaborated equally well with B cells from either parentA or parentB in the presence of accessory cells from either parent; (b) A leads to (A x B)F1 chimeric spleen cells depleted of accessory cells collaborated equally well with accessory cells from either parentA or parentB, even though the B cells only expressed the H-2 determinants of parentA. A requirement for helper T-cell recognition of K or I-A region-encoded H-2 determinants on accessory cells was also demonstrated in two ways: (a) (A x B)F1 leads to parentA chimeric spleen cells depleted of accessory cells collaborated with accessory cells from parentA but not parentB; and (b) (A x B)F1 leads to parentA chimeric helper T cells collaborated with normal F1 B cells only in the presence of parental or recombinant accessory cells that expressed the K or I-A region-encoded determinants of parentA. Although restricted in their ability to recognize H-2 determinants on accessory cells, it was demonstrated both in vitro and in vivo that (A x B)F1 leads to parentA chimeric helper T cells were able to collaborate with B cells from either parentA or parentB. In vitro in the presence of accessory cells from parentA, (A x B)F1 leads to parentA chimeric helper T cells collaborated equally well with B cells from either parent. In addition, the inability of (A x B)F1 leads to parentA chimeric helper T cells to collaborate with (B + accessory) cells from parentB was successfully reversed by the addition of parentA SAC as added accessory cells. In vivo, upon the addition of parentA accessory cells, (A x B)F1 leads to parentA chimeric helper T cells collaborated with parentB B cells in short-term adoptive transfer experiments.
Synthesis of two classes of antibody, gammaM and gammaG or gammaM and gammaA, by identical cells. Amplification of the antibody response to pneumococcal polysaccharide type III.
Authors: Pasanen V J , Asofsky R , Baker P J
Published: June 2004

Class-specific plaque-forming cell (PFC) (gammaM, gamma1, gamma2, and gammaA) responses to type III pneumococcal polysaccharide (SSS-III) were studied in BALB/c x C57BL/6F1 (CBF1) mice with and without induction of an allogeneic effect. Gamma1, gamma2, and gammaA PFC were detected in two ways: (a) With the sequential development of the assay slides, first for direct (gammaM)PFC followed by incubation with class-specific antiimmunoglobulin and complement for the development of additional gamma1, gamma2, and gammaA PFC (gammaM-independent gamma1, gamma2, and gammaA PFC); and (b) by blocking gammaM PFC with goat anti-gammaM and simultaneously developing gamma1, gamma2, and gammaA PFC (total gamma1-, gamma2-, and gammaA-secreting PFC). The results showed that whereas gammaM PFC arose on the 3rd d after immunization, gamma1-, gamma2-, and gammaA-secreting PFC arose on the 4th to 5th d after immunization. They appeared in association with gammaM-secreting PFC because they were detected with the gammaM blocking method but not with the sequential method. By the 7th d most gamma1, gamma2, and gammaA PFC were detected by the sequential method as well, indicating that those antibodies were secreted independently of cells secreting gammaM. When the numbers of double-class-secreting PFC were evaluated on the 5th d, the following results were obtained: 83% of gammaM PFC were secreting either gamma1 (25%), gamma2 (55%), or gammaA (2%). We interpret these data as evidence for an antigen-driven class differentiation from gammaM to gammaA and from gammaM to gammaG in the majority of anti-SSS-III-secreting clones without T-cell help. When an allogeneic effect was provided by inoculation of parental BALB/c spleen cells together with antigen, the numbers of all classes of PFC were increased. Furthermore, the frequency of gammaM-gammaG (108%) or gammaM-gammaA (9%) double-class secretors was increased, and gammaM-independent gammaG and gammaA secretors were detected earlier, indicating an overall maturation-promoting effect. In addition, prolonged appearance of gammaA PFC was dependent on the allogeneic effect.
Localization of H-2 antigens on mouse trophoblast cells.
Authors: Chatterjee-Hasrouni S , Lala P K
Published: June 2004

The presence of H-2 antigens of the paternal and maternal haplotypes on mouse trophoblast cells was examined at several stages of pregnancy by using a sensitive immunolabeling technique followed by quantitative radioautography. Results revealed the presence of H-2 antigens (determined by the K or D loci) of both parental haplotypes on the F1 trophoblast cells. At 14-16 d of gestation, the antigen density was equivalent to that on adult thymocytes and there was a further 50% increase on day 18. H-2 antigens of both parental haplotypes are also found to be expressed on 11-13 d trophoblast cells.
Human megakaryocytes. I. Characterization of the membrane and cytoplasmic components of isolated marrow megakaryocytes.
Authors: Rabellino E M , Nachman R L , Williams N , Winchester R J , Ross G D
Published: June 2004

Human marrow megakaryocytes have been isolated with high purity and yield by processing marrow cells sequentially through density centrifugation and velocity sedimentation. Analysis of the isolated cells for various platelet-associated components by immunofluorescence demonstrated that fibrinogen, plasma factor VIII antigen (factor VIII:AGN) platelet myosin, platelet glycoproteins I and III are present on the membrane and in the cytoplasm of over 90% of marrow megakaryocytes. Parallel studies of human and mouse megakaryocytes and platelets for IgG receptor (FcR), complement receptor type one (CR1) (C3b receptor), complement receptor type two (CR2) (C3d receptor), and Ia antigen by fluorescence and (or) rosette formation methods were performed. FcR were present on most human megakaryocytes and platelets. The Ia antigen was detected on a proportion (10-15%) of human megakaryocytes but it was undetectable on human platelets. CR1 was found on 20-40% of mouse megakaryocytes and also on a proportion of mouse platelets. These differentiation markers may be of use in monitoring megakaryocyte maturation.
Mechanisms of idiotype suppression. I. In vitro generation of idiotype-specific suppressor T cells by anti-idiotype antibodies and specific antigen.
Authors: Kim B S
Published: June 2004

Normal BALB/c spleen cells are unresponsive in vitro to the phosphorylcholine (PC) determinant in the presence of anti-idiotype antibodies specific for the TEPC-15 myeloma protein (T15) which carries an idiotypic determinant indistinguishable from that of most anti-PC antibodies in BALB/c mice. The possibility that idiotype-specific suppressor cells may be generated during the culture period was examined by coculturing the cells with untreated syngeneic spleen cells. Cells that had been preincubated with anti-T15 idiotype (anti-T15id) antibodies and a PC-containing antigen, R36a for 3 d, were capable of specifically suppressing the anti-PC response of fresh normal spleen cells, indicating that idiotype-specific suppressor cells were generated during the culture period. The presence of specific antigen also appeared to be necessary because anti-T15id antibodies and a control antigen, DNP-Lys-Ficoll, were not capable of generating such suppressor cells. Suppressor cells were induced only in the population of spleen cells nonadherent to nylon wool and the suppressive activity was abrogated by treatment with anti-Thy 1.2 serum and complement. These results indicate that anti-idiotype antibodies and specific antigen can generate idiotype-specific suppressor T cells in vitro. These in vitro results may reflect in vivo mechanisms of idiotype suppression.
Regulation of T-cell-mediated lympholysis by the murine major histocompatibility complex. I. Preferential in vitro responses to trinitrophenyl-modified self K- and D-coded gene products in parental and F1 hybrid mouse strains.
Authors: Levy R B , Shearer G M
Published: June 2004

Spleen cells from H-2b,k,d C57Bl/10 congenic mice were sensitized in vitro to trinitrobenzenesulfonate (TNBS)-modified autologous spleen cells. Cold target competition studies at the lytic phase demonstrated three distinct patterns of cytotoxic responsiveness: (a) H-2b spleen cells generated approximately equivalent CTL responses against Kb and Db modified self products, (b) H-2d spleen cells generated preferential responses against Dd modified self products, and (c) H-2k spleen cells generated cytotoxic responses which could only be detected against Kk self products in association with TNP. F1 spleen cells were sensitized against autologous TNBS-treated cells. The results showed that, although H-2b parental cells generated approximately equivalent Kb-TNP- and Db-TNP-specific CTL, the presence of the H-2b haplotype did not result in the generation of (a) Dk-TNP CTL response by (H-2b x H-2k) spleen cells, nor (b) a Db CTL response by (H-2b x H-2a) F1 spleen cells. Additionally, (H-2d x H-2k) F1 cells failed to generate detectable Dd-TNP-specific CTL, although H-2d parental cells generated D-regional-specific CTL. The findings demonstrated that these F1 response patterns paralleled those of the H-2k and H-2a parents, i.e. weak or no D-region TNP-specific CTL were induced. Because (H-2d x H-2a) F1 responders stimulated with H-2d TNBS-treated cells did generate good Dd TNP responses, the results illustrated that the presence of responder genes was not sufficient to result in a D-region TNP CML. It is suggested that the absence of Kk alleles on the stimulating population is necessary for the generation of D-region TNP CTL in these F1's. Mechanisms which could account for these response patterns in parental F1 mice are discussed including immunodominance, suppression, T-cell response , and Ir-gene defects.
The in vitro generation and sustained culture of nude mouse cytolytic T-lymphocytes.
Authors: Gillis S , Union N A , Baker P E , Smith K A
Published: June 2004

In addition to allowing for the long-term culture of both murine and human cytolytic T lymphocytes, T-cell growth factor (TCGF) functions as the key proliferation-inducing second signal in both T-cell antigen sensitization and mitogenesis. The observation that thymocytes responded normally to T-cell mitogens in the presence of TCGF, prompted the investigation of the effect of TCGF on nude mouse lymphocyte responses in vitro. We found that spleen, lymph node, and bone marrow cells, isolated from nude mice, were incapable of producing TCGF yet responded normally to T-cell mitogen sensitization provided stimulation was conducted in the presence of TCGF. Nude mouse spleen cells were also capable of responding to alloantigen sensitization in mixed lymphocyte cultures (NLMC) conducted in the presence of TCGF. Thy-1 antigen-positive cells harvested from TCGF-supplemented nude mouse MLC effectively mediated the cytolysis of alloantigen-specific target cells as tested in standard 51Cr-release assays. Cytolytic nude mouse effector cells have remained in TCGF-dependent culture for over 3 mo during which they have continued to mediate significant levels of alloantigen-specific cytolytic reactivity. These results suggest that prothymocytes present in nude mice are capable of responding to immunologic stimuli by differentiating, in vitro, into cytolytic T lymphocytes and that furthermore, a major function of the thymus may be to effect the maturation of TCGF-producing cells.
Tumors induced by murine sarcoma virus contain precursor cells capable of generating tumor-specific cytolytic T lymphocytes.
Authors: Chapdelaine J M , Plata F , Lilly F
Published: June 2004

Leukocyte fractions extracted from the tumor mass and the lymphoid organs of C57BL/6 (B6) mice carrying murine sarcoma virus-induced tumors contained primed cytolytic T-lymphocyte (CTL) precursor cells, in addition to active cytotoxic T cells. These leukocyte fractions gave a secondary response when stimulated in vitro with syngeneic tumor cells, generating large numbers of specific CTL. The activity of these CTL (H-2b) was apparently H-2-restricted, because it was ineffective on tumor targets bearing strongly cross-reacting tumor-specific antigens but with the H-2d haplotype. Furthermore, only H-2b cells bearing the Friend, Moloney, Rauscher-associated antigen, such as Rauscher leukemia virus-induced RBL-5 cells and Friend leukemia virus-induced HFL/b cells, were lysed efficiently. B male GV cells (H-2b cells induced by Gross leukemia virus) were not affected by the same CTL. We propose the existence of a dynamic state involving the migration of primed CTL precursor cells between the lymphoid organs and the tumor mass, as well as the differentiation of these precursor cells within the tumor mass into highly specific CTL.
Anti-Friend virus antibody is associated with recovery from viremia and loss of viral leukemia cell-surface antigens in leukemic mice. Identification of Rfv-3 as a gene locus influencing antibody production.
Authors: Doig D , Chesebro B
Published: June 2004

A single genetic locus, Rfv-3, influenced Friend virus (FV) viremia, loss of FV-induced cell-surface antigens from leukemia cells, and generation of anti-FV antibodies. 30--90 d after FV infection leukemic spleen cells from (B10.A X A)F1 and (B10.A X A.BY)F1 mice (Rfv-3r/s) were found to have low FV-induced cell-surface antigen expression compared to leukemic spleen cells from A and A.BY mice (Rfv-3s/s). In addition, these F1 mice recovered from viremia and generated cytotoxic anti-FV antibodies. A and A.BY mice did not recover from viremia and failed to generate anti-FV antibodies. Anti-FV leukemia cell antibody appeared to mediate FV-antigen loss because decrease of FV cell-surface antigens occurred at the same time as anti-FV antibody appeared in the plasma of F1 mice, and passive transfer of anti-FV antisera induced modulation of FV cell-surface antigens. Rfv-3 did not influence an intrinsic ability of FV antigens to be modulated from Rfv-3s/s leukemia cells because FV antigen loss from Rfv-3s/s spleen cells occurred after transfer of cells to an immune environment.
Qat-4 and Qat-5, new murine T-cell antigens governed by the Tla region and identified by monoclonal antibodies.
Authors: Hämmerling G J , Hämmerling U , Flaherty L
Published: June 2004

Two new lymphocyte antigens, provisionally designated Qat-4 and Qat-5 have been identified with two different hybridoma-derived, monoclonal AKR antiC57BL/6 antibodies. These antigens are governed by genes located to the right (distal) end of the H-2 complex, within the Qa-2,3 region. Qat-4 and Qat-5 antigens which do not seem to be identical with Qa-2,3 or TL antigens are absent from Ig/ lymphocytes and thymocytes. They are only present on a fraction of peripheral T cells. Thus, Qat-4 is expressed on 70%, and Qat-5 on 30% of splenic and lymph node T cells, Qat-4 is also found on the majority of Ig- cells from athymic nude mice. These findings illustrate the complexity of the chromosome segment between the H-2D and Tla loci and they emphasize the role of major histocompatibility complex-associated genes for the differentiation of T cells into different subpopulations with possibly distinct immunologic functions.
Production of auto-anti-idiotypic antibody during the normal immune response to TNP-ficoll. I. Occurrence in AKR/J and BALB/c mice of hapten-augmentable, anti-TNP plaque-forming cells and their accelerated appearance in recipients of immune spleen cells
Authors: Schrater AF , Goidl EA , Thorbecke GJ , Siskind GW
Published: June 2004

Attempts were made to elucidate the cause of the downward regulation of the splenic plaque-forming cell (PFC) response in AKR/J and BALB/c mice between days 4 and 7 after a single intravenous injection of 2,4,6,trinitrophenyl- lys-Ficoll(TNP-F). AKR/J spleen cells, taken 7 d after injection of TNP-F, were transferred, together with TNP-F, into normal AKR/J mice. The day-3 or -4 PFC response of the recipients was much lower than that of recipients of normal cells. However, the suppression was only apparent because the presence of 10(-8)-10(-7) M 2,4,6-trinitrophenyl-ε-amino-n-caproic acid (TNP- EACA) (or 10(-7)-10(-6) M 2,4,-dinitrophenyl-ε-amino-n-caproic acid) in the PFC assay caused a dramatic increase in observed PFC, averaging 298 percent on day 3 and 122 percent on day 4. Recipients of normal cells showed no such hapten-augmentable PFC. T-depleted immune spleen cells did not cause any apparent suppression of the response to TNP-F, but hapten-augmentable PFC in recipient spleens were again prevalent. Suppression of the PFC response, as well as hapten-augmentable PFC, were seen after transfer of immune serum. It was postulated that hapten augmentation of PFC was caused by displacement of auto-anti-idiotypic antibody from the surface of blocked antibody- synthesizing cells.

Further studies showed that such hapten-augmentable PFC occurred in the spleens of a large percentage of both AKR/J and BALB/c mice examined after day 4 of the primary response to TNP-F. Thus, it was hypothesized that the downward regulation of the magnitude and, possibly, also of the heterogeneity of the splenic-PFC response was due to an auto-antibody response to one or more major idiotypes of the anti-TNP response.
The generation and specificity of cytotoxic T cells raised against syngeneic tumor cells bearing AKR/gross murine leukemia virus antigens
Authors: Green WR , Nowinski RC , Henney CS
Published: June 2004

Efforts were made to generate C57BL/6 cytotoxic effector cells to a syngeneic leukemia (E{male}G2) bearing AKR/Gross virus antigens. As we were unable to induce significant cytotoxic activity by immunization with up to 10(8) irradiated E{male}G2 cells, even when cells from such primed animals were subsequently restimulated with E{male}G2 cells in vitro, C57BL/6 mice were immunized with an aliogeneic, virus-producing AKR leukemic cell line (AKR SL3).

Peritoneal exudate cells and, to a lesser degree, spleen cells from these mice showed significant lytic activity toward the immunizing allogeneic tumor but not toward E{male}G2. When spleen cells were harvested from animals {approximately equal to}10 d after injection of AKR SL3 and rechallenged in vitro with either E{male}G2 or AKR.H-2(b) SL1, another tumor that displays AKR/Gross virus antigens, then a vigorous cytotoxic response against E{male}G2 and AKR. H-2(b) SL1 was obtained.

Effector cells generated by AKR SL3 priming followed by in vitro stimulation with E{male}G2 or AKR.H-2(b) SL1 lysed only cells of H-2(b) haplotype which were strongly positive for the display of serologically detectable AKR/Gross virus antigens. Thus, AKR SL3 cells were not lysed nor were EL4 cells (H-2(b); but only weakly positive for gp70). Cells not bearing the MuLV antigens tested for, such as P815 mastocytoma cells and spleen cell "blasts" from C57BL/6 and CBA (H-2(k)) mice, were also insusceptible to attack. The cytotoxic effector cells induced bore Thy 1.2 alloantigen and were of the Lyt 1+2+ phenotype.

Collectively, these findings are consistent with the conclusion that the cytotoxic T cells raised against E{male}G2 are directed against AKR/Gross virus-associated antigens and are H-2 restricted. It will be of interest to determine the relevance of such effector cells to the known resistance of the C57BL/6 mouse to AKR/Gross virus-induced leukemia.
In vitro model for natural tolerance to self-antigens. Inhibition of the development of surface-immunoglobulin-negative lymphocytes into T-dependent responsive B cells by antigen.
Authors: Teale J M , Layton J E , Nossal G J
Published: June 2004

Neonatal and adult splenic cell suspensions were labeled with fluorescein isothiocynate-anti-Ig and fractionated into surface-immunoglobulin- (s-Ig) positive and s-Ig-negative subpopulations by the fluorescence-activated cell sorter. The subpopulations were then tested by splenic focus assay for both frequency and tolerance susceptibility of clonable 2,4,-dinitrophenol (DNP) precursors. It was shown that both adult, and neonatal, s-Ig-negative subsets contained clonable DNP-specific B-cell precursors. However, because these precursors result in fewer clones secreting IgG, they appeared to be less mature than the s-Ig-positive precursors. In the absence of helper T cells, it was found that exposure of s-Ig-negative lymphocytes to tolerogen during the process in which they were acquiring surface receptors resulted in nearly total abrogation of potential DNP clones. This finding provides compelling evidence for clonal abortion.
Effect of cytochalasin B on the maturation of enveloped viruses.
Authors: Griffin J A , Compans R W
Published: June 2004

The maturation of two enveloped viruses, influenza and vesicular stomatitis, occurs in cells treated with cytochalasin B. Virions produced in the presence of 50 microgram/ml cytochalasin B (CB) appear to be as infectious as those from control cells, indicating that polymerized actin is not required for the assembly of functional viral components. CB inhibits the release of influenza virus from treated cells, a phenomenon which appears to be a result of the synthesis of an aberrant neuraminidase (NA) glycoprotein; virions grown in CB-treated cells had a 90% reduction in specific enzymatic activity. We found that both influenza viral glycoproteins (NA and Hemagglutinin glycoprotein) had faster electrophoretic mobilities and were more heterogeneous in CB-treated cells as compared with controls. We also observed complete inhibition of incorporation of labeled glucosamine into viral glycoproteins in the presence of the drug. It was of interest that CB-induced inhibition of glycosylation appeared to cause loss of neuraminidase function, whereas hemagglutinating activity was not noticeably impaired. The presence of altered glycoproteins did not significantly diminish the infectivity of either influenza virus or vesicular stomatitis virus. Our results indicate that no step in the maturation of enveloped viruses is dependent upon an intact cytoskeletal network.
Generation of unique mono-hydroxy-eicosatetraenoic acids from arachidonic acid by human neutrophils.
Authors: Goetzl E J , Sun F F
Published: June 2004

Incubation of [3H]arachidonic acid with the 17,000-g supernatant from homogenates of human neutrophils in the presence of indomethacin generated the unique metabolites 9-OH-5,7,11,14-eicosatetraenoic acid (9-HETE) and 8-HETE, in addition to 12-HETE, 11-HETE and 5-HETE. The human neutrophil chemotactic activity of the HETE products exhibited a rank-order of potency with 5-HETE greater than 8-HETE = 9-HETE greater than 11-HETE = 12-HETE. The expression of chemokinetic activity as well as chemotactic activity suggested that the endogenous production of these principles may influence the mobility of human neutrophils.
The induction of hapten-specific immunological tolerance and immunity in B lymphocytes. VI. Differential tolerance susceptibility in adult spleen as a function of B-cell maturation level.
Authors: Fidler J M
Published: June 2004

The maturation level of the B-lymphocyte subpopulations involved in trinitrophenyl (TNP)-specific immunological tolerance in adult mice induced by the injection of trinitrobenzenesulfonic acid (TNBS) was investigated using in vitro antigen-specific and nonspecific polyclonal stimulation. The maturity of the B-cell subsets being studied was defined by the antigen or polyclonal activator which evoked a response. Thus, the thymic independent (TI-1) antigen TNP-lipopolysaccharide (TNP-LPS) and the polyclonal stimulant LPS were used to activate immature, neonatal-type B lymphocytes, whereas mature, adult-type B cells were responsive to the TI-2 antigen, TNP-Ficoll, and the nonspecific activator, purified protein derivative (PPD). Whereas unresponsiveness in TNP-LPS-reactive (immature) B cells 4 d after TNBS treatment was previously shown to be the result of functional deletion, partially reversible receptor blockade was detected in this study early after tolerogen treatment. By the 24-h point, tolerance was irreversible, as assessed by 24-h of antigen-free incubation and cocultivation of tolerant cells with control splenocytes. Tolerance was induced more rapidly in immature, TI-1 B cells than in mature TI-2 B lymphocytes. B lymphocytes reactive to TNP-Ficoll were also less susceptible to receptor blockade. Using LPS as a nonspecific probe for immature B cells, 60% tolerance in high affinity TNP-specific cells was induced within 12 h of TNBS treatment, and complete unresponsiveness by 24 h. In contrast, no significant decrease in response to the mature B-cell activator, PPD, occurred until day 2. Furthermore, the 50% tolerance level was achieved in TNP-specific LPS-reactive B cells by 100 times less tolerogen than required for PPD-responsive cells. Thus, TNBS-induced unresponsiveness in cells reactive to TNP-LPS is initially a result of reversible receptor blockade which leads within 4 d to functional deletion. Immature, TI-1 B lymphocytes, which give polyclonal responses to LPS and antigen-specific responses to TNP-LPS, are rendered tolerant to TNBS more rapidly and at lower tolerogen does than mature, TI-2 mouse B cells which react polyclonally to PPD and specifically to TNP-Ficoll. Moreover, these data show that both the immature and the mature B lymphocyts with these characteristic tolerance susceptibilities and specific and nonspecific immune response patterns are present in the adult mouse spleen.
Suppression of IgE antibody production in SJL mice. IV. Interaction of primed and unprimed T cells.
Authors: Itaya T , Ovary Z
Published: June 2004

The mechanism of selective anti-hapten IgE antibody production was studied in SJL mice. Using an adoptive transfer method of spleen cells into syngeneic recipients irradiated with a sublethal dose of 600 rads, it was demonstrated that for the suppression of anti-dinitrophenyl (DNP) IgE antibody production the interaction of two subsets of T cells is necessary. DNP-primed B cells and carrier-primed T helper cells are taken from donors primed with small amounts of DNP-carrier conjugates. Without injection of other cells, high titer and persistent anti-DNP antibodies are produced in the recipients. The two subsets of T cells that are active in suppression of IgE are taken from two types of donors: one donor is immunized (hyperprimed) with larger amounts of carrier protein twice, the other is an unprimed donor. The carrier for hyperpriming the first type of donor may be unrelated to the carrier used for priming the helper T cells. To bring about anti-DNP IgE suppression it is necessary that the animals should be challenged with the same DNP-carrier conjugate used for priming the B and T helper cells. If the hyperprimed donors were immunized with a heterologous, unrelated carrier, then this heterologous unconjugated carrier must also be injected together with the homologous DNP-carrier conjugate. In these conditions, anti-DNP IgE antibody production is suppressed, but the production of anti-DNP IgG1 antibody is not diminished.
Hybrid resistance to EL-4 lymphoma cells. I. Characterization of natural killer cells that lyse EL-4 cells and their distinction from marrow-dependent natural killer cells.
Authors: Kumar V , Luevano E , Bennett M
Published: June 2004

Natural killer (NK) cells from nonimmunized mice capable of lysing EL-4 (C57BL/6 strain H-2b) tissue culture-adapted lymphoma cells have been analyzed and compared with NK cells which lyse YAC-1 (A-strain, H-2a) lymphoma cells. A correlation was seen in the ability of inbred and B6D2F1 mice to reject C57BL/6 (B6) bone-marrow grafts and the ability of their spleen cells to lyse EL-4 cells in vitro. This suggests that hybrid or hemopoietic histocompatibility antigens, (Hh-1b), relevant in the rejection of B6 stem cells may also be the relevant target structures for the anti-EL-4 NK cells. Certain features of these NK cells are similar to the NK cells reactive against YAC-1 cells. Both types of NK cells are present in athymic nude mice, are not affected by treatment with anti-immunoglobulin plus complement, and are not depleted by techniques that remove macrophages. NK activity against both targets is stimulated 3 d after injection of Corynebacterium parvum, and 24 h after challenge with polyinosinic:polycytidylic acid. Hydrocortisone acetate and cyclophosphamide lead to reduction of NK activity within 2-3 d after administration. However, the anti-YAC and anti-EL-4 NK reactivities differed in several important respects. Treatment of mice with 89Sr, the bone-seeking isotope, to deplete marrow-dependent cells, depleted the anti-YAC-1 but not anti-EL-4 cell functions. Anti-EL-4 NK cells were unaffected by silica particles in vivo or in vitro; the NK cells reactive to EL-4 cells matured functionally much earlier in life (5 d of age) and the function did not decline with age. Irradiated mice reconstituted with syngeneic marrow or spleen cells developed functional NK cells against EL-4 targets before they developed anti-YAC-1 NK cells in their spleen. Thus anti-EL-4 NK cells that express hybrid resistance in vitro appear to differ from anti-YAC-1 NK cells and do not require an intact marrow microenvironment for functional differentiation. Despite differences in the NK-cell types involved in the lysis of YAC-1 and EL-4 cells, these two tumor cells share certain common determinants. This was ascertained both by cold competition and by utilization of YAC-1 and EL-4 cell monolayers as immunoadsorbents. We conclude that Hh-1b is the common antigen present in EL-4 and YAC-1 cells, because B6D2F1 anti-B6 (anti-Hh-1b) cytotoxic T lymphocytes lysed both the tumor cells. Our data suggest that Hh-1b antigen is recognized by both types of NK cells, but that additional determinants must be present on YAC-1 cells. Two models of NK cell lysis compatible with the data are presented.
Human complement in thrombin-mediated platelet function: uptake of the C5b-9 complex.
Authors: Polley M J , Nachman R L
Published: June 2004

Thrombin-mediated platelet aggregation and release is enhanced by the presence of C3, C5, C6, C7, C8, and C9 of human complement. The interaction of thrombin with its receptor on the platelet membrane initiates activation of complement on the platelet surface. Trypsin-mediated platelet function is not enhanced by the addition of complement, probably because trypsin has no receptor on the platelet surface so activation of complement is triggered in the fluid phase and not on the platelet surface. Activation of complement by thrombin led to production of dimers of the C5b-9 complex on the platelet surface. These complexes were eluted from the platelet membrane and were identified physicochemically and morphologically. The mechanism of complement-induced enhancement of platelet function is not clear, however, it probably is mediated via the arachidonic acid transormation pathway because this activity was blocked by known inhibitors of cyclo-oxygenase, namely, aspirin and indomethacin.
Suppressor T-cell mechanisms in contact sensitivity. III. Apparent non-major histocompatibility complex restriction is a result of multiple sets of major histocompatibility complex-specific suppressor T cells induced by syngeneic 2,4-dinitrophenyl-modified lymphoid cells.
Authors: Miller S D
Published: June 2004

This report has examined the mechanisms by which major histocompatibility complex (MHC) non-restricted suppressor T cells (Ts), induced by the i.v. injection of 2,4-dinitropheny (DNP)-modified, syngeneic lymphoid cells (DNP-LC), suppress the passive transfer of contact sensitivity mediated by syngeneic and allogeneic immune delayed hypersensitivity T cells (TDH). In terms of suppression of syngeneic TDH, it was found that the suppressive action of the Ts was only blocked by pretreatment with soluble syngeneic DNP-LC membrane preparations. Monomeric DNP-lysine, polymeric DNP-protein conjugates, and syngeneic TNP-LC membranes did not inhibit Ts function. Further experiments showed that inhibition of syngeneic suppression could be achieved by DNP-modified-membrane preparations that were only H-2D-region compatible with the Ts donor. Thus, Ts antigen receptors in this system specifically recognize DNP-modified H-2D-region determinants. In contrast, it was found that pretreatment os syninduced Ts with syngeneic DNP-LC membranes did not inhibit the ability to suppress allogeneic TDH. However, pretreatment of Ts with DNP-allogeneic membranes which were H-2D-end compatible to the allogeneic target TDH eliminated their ability to suppress the specific allogeneic TDH, leaving intact suppression of syngeneic or third party TDH. It is proposed that perturbation of the immune system by i.v. injection of syngeneic NDP-LC leads to the induction of a polyclonal wave of DNP-specific Ts activity. Some members of this set of Ts recognize DNP-self MHC determinants with moderate affinity and are thus specifically inhibited after pretreatment with those DNP-self determinants. Other members of this set display receptors which cross-react with high affinity with DNP-allogeneic determinants and thus suppress allogeneic TDH cells. These allosuppressive clones can thus be specifically inhibited only by pretreatment with DNP-LC membranes, MHC-compatible with the target TDH. The data are discussed in terms of current models of T-cell cross-reactivity and T-cell-receptor recognition.
Generation of anti-type III pneumococcal polysaccharide hybridomas from mice with an X-linked B-lymphocyte defect.
Authors: Schroer K R , Kim K J , Prescott B , Baker P J
Published: June 2004

(CBA/N X BALB/c male)F1 mice bear on X-linked defect making them totally unresponsive to T-independent (TI), TI-2 antigens such as type III pneumococcal polysaccharide (SSS-III). We found that somatic cell hybrids between CB nonresponder spleen cells and NS1 plasmacytoma cells secreted antibody specific for SSS-III. The solid-phase binding of such antibody was completely inhibited by the addition of free antigen (SSS-III) and the amount of antibody detected in culture fluids ranged from 10 ng/ml to 10 micrograms/ml. Eight hybridoma clones were identified; all make antibody of the IgM class. These results indicate that the X-linked defect does not result in a deletion of a B-cell subset which responds to TI-2 antigens.
Site of binding of mouse IgG2b to the Fc receptor on mouse macrophages.
Authors: Diamond B , Birshtein B K , Scharff M D
Published: June 2004

Three mouse immunoglobulins with altered heavy chains have been used to study the specificity of the mouse IgG2b Fc receptor on mouse macrophages. These immunoglobulins were synthesized by variant clones derived from the MPC 11, IgG2b-producing mouse myeloma cell line. One variant, whose Fc receptor. A second variant, which makes a short heavy chain lacking the CH3 domain, binds specifically to the IgG2b Fc receptor. The third variant makes a hybrid IgG2b-IgG2a heavy chain whose CH3 domain is enterely IgG2a-like and binds to both IgG2a and IgG2b Fc receptors. These data suggest that the binding of mouse IgG2b immunoglobulins to the mouse macrophage Fc receptor involves a site within the CH2 domain and indicate that immunoglobulins with altered heavy chains are a useful tool to probe Fc receptors.
Inhibition of H-Y cell-mediated cytolysis by H-2Db antiserum.
Authors: Koo G C , Goldberg C L , Shen F W
Published: June 2004

Assays of H-Y-specific cell-mediated cytolysis (CMC) in vitro were carried out with B6 female effector cells and B6 male target cells. This lytic system depends on compatibility for H-2Db but not for H-2Kb. Antibody to H-2Db but not to H-2Kb blocked the CMC assay. However, maximal blocking required exposure to the target cells to H-2Db antibody for up to 2 h. This interval is far longer than would be required for blocking of a pre-existing H-Y:H-2Db complex, and seems more consonant with a membrane reorganization bringing H-Y and H-2Db together, as proposed from mapping studies. The question whether the postulated configurational change affecting H-Y and H-2Db is a necessary feature of CMC awaits further study.
Diacylglycerol metabolism in mast cells: a potential role in membrane fusion and arachidonic acid release.
Authors: Kennerly D A , Sullivan T J , Sylwester P , Parker C W
Published: June 2004

Purified rat peritoneal mast cells stimulated with the polycationic histamine-releasing agent compound 48/80 demonstrated a two- to four-fold increase in cellular levels of 1,2-diacylglycerol (DAG) within 1 min as detected by radioactive labeling and direct quantitation experiments. When 2-[1-14C]arachidonoyl-DAG was incubated in the presence of mast-cell homogenates, a rapid conversion to free arachidonate, and to a lesser extent, to monoacylglycerol, triglyceride, and phospholipid was observed. The release of arachidonate was proportional to the amount of broken-cell preparation added and the time of incubation, was prevented by preheating mast-cell preparations, and did not occur when 1-[1-14C]arachidonoyl-phosphatidylcholine was used as substrate, suggesting that the degradation was mediated by an enzyme with Dag-lipase activity. Although much work remains to be done to clarify the precise role of DAG in mast cells, DAG metabolism may be involved in secretion by generating substances which may faciliate membrane fusion and also in arachidonic acid-derived mediator formation by liberating esterified arachidonic acid from mast-cell lipids. Taken together, these studies indicate that the formation of DAG may play a central role in mast-cell function.
Studies on the clonal origin of multiple myeloma. Use of individually specific (idiotype) antibodies to trace the oncogenic event to its earliest point of expression in B-cell differentiation.
Authors: Kubagawa H , Vogler L B , Capra J D , Conrad M E , Lawton A R , Cooper M D
Published: June 2004

IgA myeloma proteins of kappa- and lambda-types were isolated from two patients. These were used to produce and purify anti-idiotype antibodies of both broad (myeloma-related) and narrow (individual myeloma) specificities. The anti-idiotype antibodies were conjugated with fluorochromes and used as immunofluorescent probes to trace in the patients clonal expansion at different levels of B-cell differentiation. Our results (a) confirm that B lymphocyte precursors in IgA plasma-cell myelomas are involved in the malignant process, (b) show that B lymphocytes of the malignant clone include those expressing each of the major heavy-chain isotypes, mu, delta, gamma, and alpha, and (c) provide strong circumstantial evidence that pre-B-cell members of the malignant clone are also increased in frequency. T cells expressing idiotypic determinants were not detected. These findings argue that the initial oncogenic event may occur in a B-stem cell and is not influenced through stimulation by antigen. An interesting association was the increased frequency of related clones of B lymphocytes as detected by their reactivity with anti-idiotype antibodies of broad specificity. Neither plasma cell nor pre-B-cell members of these related clones were increased in frequency. Anti-idiotype antibodies or helper T cells reactive with myeloma-related idiotypes could be responsible for this phenomenon. We discuss other implications of these findings and speculate that all of the various phenotypes of B-lineage malignancies may result from oncogenic processes affecting stem cell targets.
Production of auto-anti-idiotypic antibody during the normal immune response to TNP-ficoll. III. Absence in nu/nu mice: evidence for T-cell dependence of the anti-idiotypic-antibody response.
Authors: Schrater A F , Goidl E A , Thorbecke G J , Siskind G W
Published: June 2004

Although athymic mice make an excellent immune response to the thymus-independent antigen trinitrophenyl-lys-Ficoll (TNP-F), nude mice of AKR/J and BALB/c strains lack the anti-idiotypic response that occurs in euthymic mice of both of these strains within the first 1--2 wk after injection of more TNP-F. Anti-idiotypic antibody-blocked (hapten-augmentable) anti-TNP splenic plaque-forming cells (PFC) do not occur at any time and serum anti-idiotypic antibody is absent in both congenitally athymic mice, and thymectomized, irradiated, bone marrow-reconstituted mice. Nevertheless, nu/nu mice do have PFC which can be inhibited by exposure to anti-idiotypic antibody produced in +/+ mice. As a consequence of the failure to produce anti-idiotypic antibodies, the anti-TNP PFC response is athymic as compared to euthymic mice is of greater magnitude, declines less precipitously, and shows an increase rather than a decrease in affinity between days 4 and 7 after antigen injection. It is concluded that the anti-idiotypic antibody response is thymus dependent and that athymic mice lack a helper cell required for the induction of anti-idiotypic antibodies.
T-lymphocyte response to cytochrome c. I. Demonstration of a T-cell heteroclitic proliferative response and identification of a topographic antigenic determinant on pigeon cytochrome c whose immune recognition requires two complementing major histocompatibility complex-linked immune response genes.
Authors: Solinger A M , Ultee M E , Margoliash E , Schwartz R H
Published: June 2004

The T-lymphocyte proliferative response to pigeon cytochrome c was studied in the mouse. H-2a and H-2k strains were responders to this antigen whereas H-2b, H-2d, H-2f, H-2ja, H-2p, H-2q, H-2r, H-2s, and H-2u strains were low or nonresponders. Genetic mapping demonstrated that two major histocompatibility complex (MHC)-linked Ir genes control the response, one in I-A, the other in I-E/I-C. The major antigenic determinant recognized in this response was localized by cross-stimulations with species variants and cyanogen bromide cleavage fragments of cytochrome c. It was found to be a topographic surface determinant composed of an isoleucine for valine substitution at residue 3, a glutamine for lysine substitution at residue 100 and a lysine for glutamic acid substitution at residue 104. Tobacco hornworm moth cytochrome c, which contains a glutamine at residue 100 but a terminal lysine at residue 103 (one amino acid closer to the glutamine), stimulated pigeon cytochrome c immune T cells better than the immunogen. This result demonstrates for the first time a functional T-cell heteroclitic proliferative response in a system under Ir gene control. Immunization with the cyanogen bromide cleavage fragments revealed that only pigeon cytochrome c fragment 81-104 was immunogenic. This fragment primed for a T-cell proliferative response whose specificity was nearly identical to that of the T-cell response primed for by the whole molecule, suggesting that the glutamine at 100 and the lysine at 104 form the immunodominant portion of the antigenic site. Furthermore, mixing experiments using the two cross-reacting antigens, hippopotamus cytochrome c and Pekin duck or chicken cytochrome c fragment (81-104), each of which contains only one of the two immunodominant substitutions, demonstrated that the T lymphocytes responding to the major antigenic determinant comprise a single family of clones that recognize both amino acids as part of the same determinant. Thus, two complementing MHC-linked Ir genes can control the immune response to a single antigenic determinant.
Biochemical and biological characterization of lymphocyte regulatory molecules. I. Purification of a class of murine lymphokines.
Authors: Watson J , Gillis S , Marbrook J , Mochizuki D , Smith K A
Published: June 2004

Murine spleen cells activated by concanavalin A (Con A) in culture produce a class of lymphokine molecules which possess biological activity in a number of lymphocyte response assays. Lymphokines with a mol wt of 30,000, as estimated from gel filtration studies, can be resolved into two components which differ by charge, with isoelectric point (pI) values of 4.3 and 4.9, respectively. Both components stimulate (a) the growth of established T-cell lines in culture, (b) the proliferation of thymocytes in the presence of Con A under culture conditions where Con A alone is nonmitogenic, (c) the induction of antibody responses to heterologous erythrocyte antigens in athymic (nude) spleen cultures, (d) the generation of cytotoxic T lymphocytes (CTL) in thymocyte cultures, and (e) the generation of CTL in nude spleen cultures. In each of these culture systems we suggest that the assays are detecting a single class of lymphokine which acts directly on activated T cells. Nonactivated T cells must be stimulated by either antigen or mitogen before becoming responsive to lymphokine, but do not require antigen or mitogen for continued growth with lymphokine. The two molecular species, separable by isoelectric focusing are referred to as the T-cell growth factor (TCGF). A lymphokine, similar in size (30,000 daltons) to TCGF but heterogeneous in charge (pI 3.0--4.0), stimulates immune responses to erythrocyte antigens in T-cell-depleted spleen cultures but has no stimulatory activity in the other lymphocyte assay systems described. The data have been interpreted as showing the two molecular forms of murine TCGF (pI 4.3 and 4.9) are responsible for many of the lymphokine activities described elsewhere as thymocyte mitogenic factor, nonspecific T-cell-replacing factor and killer helper factor or costimulator. The other lymphokine, separable from TCGF by charge, appears to have true T-cell-replacing activity.