bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential major histocompatibility complex-related activation of idiotypic suppressor T cells. Suppressor T cells cross-reactive to two distantly related lysozymes are not induced by one of them.
Authors: Adorini L , Harvey M A , Rozycka-Jackson D , Miller A , Sercarz E E
Published: June 2004

B10 (H-2b) mice are genetic nonresponders to hen egg-white lysozyme (HEL) and the distantly related human lysozyme (HUL). However, anti-HEL or anti-HUL primary antibody responses in vivo or in vitro can be obtained in B10 mice by immunization with the appropriate lysozyme coupled to erythrocytes. T cells able to suppress either anti-lysozyme plaque-forming cells (PFC) response are induced in B10 mice after immunization with HEL-complete Freund's adjuvant (CFA) or HUL-CFA. This cross-reactivity of HEL and HUL in the induction and the expression of suppressive activity is in marked contrast to their very low cross-reactivity at the PFC level. These results suggest that either HEL or HUL can stimulate a suppressor T cell which recognizes a particular epitope present on both lysozymes. Suppressor cells induced by HEL or HUL bear the same predominant idiotype found on the majority of anti-HEL antibodies, and on the small proportion of anti-HUL antibodies cross-reactive with HEL. B10.Q (H-2q) mice are responders in vivo to HEL-CFA, but not to HUL-CFA. In contrast to B10, HEL-CFA priming in B10.Q micr induces helper cells whereas HUL-CFA priming induces suppressor cells. These suppressor cells are cross-reactive with HEL and are fully able to suppress HEL-specific helper cells. The presence of HEL-specific suppressor cell precursors in B10.Q mice which are not activated by HEL, seems to implicate differential choice by the antigen presenting system as a basis for Ir gene control, rather than the absence of a regulatory cell type from the T cell repertoire.
An autosomal dominant gene regulates the extent of 9-O-acetylation of murine erythrocyte sialic acids. A probable explanation for the variation in capacity to activate the human alternate complement pathway.
Authors: Varki A , Kornfeld S
Published: June 2004

Nydegger et al. (4) have reported that the difference in susceptibility of erythrocytes from different inbred murine strains to lysis by the human alternate complement pathway is determined by an autosomal locus. We have found a good correlation between the degree of O-acetylation of the erythrocyte sialic acid residues and the susceptibility to complement lysis, whereas there was no correlation between total erythrocyte sialic acid content and complement sensitivity. The major O-acetylated species in all the murine strains is 9-O-acetyl-N-acetylneuraminic acid. We propose that the autosomal dominant locus, which determines complement sensitivity, acts by influencing the extent of 9-O-acetylation of the erythrocyte sialic acid residues. By using recombinant inbred strains, we determined that this genetic locus is probably located on chromosome 9. The nature of the gene product remains unknown.
Two distinct antigen-specific suppressor factors induced by the oral administration of antigen.
Authors: Mattingly J A , Kaplan J M , Janeway C A
Published: June 2004

The feeding of sheep erythrocytes (SRBC) to mice leads to the production of two distinct T cell-derived suppressor factors by spleen cells. Each has been characterized for specificity, genetic restrictions, and cellular interactions. Fraction I has a 60,000-75,000 mol wt, is specific for antigen, and is suppressive of primary in vitro anti-SRBC responses at all times. It is not restricted by major histocompabitility complex (MHC)- or Igh-linked genes, but it fails to suppress spleen cells derived from any strain of mouse with a B10 background. It acts on an Lyt-2+ T cell to increase suppressive activity. An antiserum has been prepared against this factor that reacts with other, unrelated T cell suppressor factors. Fraction II has an approximately 30,000-40,000 mol wt, is specific for antigen, and has a dual effect on in vitro anti-SRBC responses. On day 3 of culture, it leads to augmentation of the response, whereas at day 5 it suppresses the response. It is not restricted by MHC genes, but it is restricted by Igh-linked genets. It acts by activating an Ly-1 t cell to both help and induce feedback suppression. These factors, and the antisera prepared against them, should allow more precise dissection of the molecular pathways by which immunoregulatory cells communicate with one another.
Immunological regulation of experimental cutaneous leishmaniasis. III. Nature and significance of specific suppression of cell-mediated immunity in mice highly susceptible to Leishmania tropica.
Authors: Howard J G , Hale C , Liew F Y
Published: June 2004

BALB/c mice have been an exceptional susceptibility to Leishmania tropica infection such that cutaneous lesions grow without restraint in all cases leading to fatal metastasis and visceralization in normal and x-irradiated, bone-marrow reconstituted (XBM) animals. Adult thymectomized, x-irradiated, bone marrow-reconstituted (ATxXBM) BALB/c mice, however, show pronounced retardation of lesion growth leading to some survival and even cures. A similar trend was also found in moderately susceptible (BALB/c X C57BL/6)F1 mice, in contrast with the "resistant" CBA strain, in which, as previously known, ATxXBM animals showed impairment of normal, spontaneous self-healing. These convere effects are paralleled by respective leishmania-specific delayed-type hypersensitivity (DTH) reactivities, prior thymectomy leading to diminution in CBA and augmentation in BALB/c and (BALB/c X C57BL/6)F1. Anti-leishmanial DTH responses, amplfiable by cyclophosphamide pretreatment, can be detected in BALB/c mice within 10 d of infection with 2 X 10(7) promastigotes, but becomes near-totally suppressed by day 25-35. No such suppressin is found in CBA, C57BL/6, or (BALB/c X C57BL/6)F1 mice together with varying degrees of immune control of lesion development or regression. Suppression of DTH in BALB/c mice is leishmania specific and does not extent to 2,4-dinitrofluorobenzene (DNFB) or sheep erythrocytes specificities. Spleen cells from suppressed L. tropica-infected mice when transferred to normal BALB/c mice impaired the induction of DTH to leishmanial antigen. This property resided in the T cell-enriched fraction and not in the T cell-depleted fraction. It is concluded that a major component of the striking inability of BALB/c mice to control L. tropica infection involves profound impairment of a potentially curative cell-mediated immune response by suppressor T cell generation. The possibility is discussed that this may be secondary to rapid amastigote (antigen) accumulation in macrophages expressing the primary genetic "defect."
Macrophages elicited with heat-killed bacillus Calomette-Guérin protect C57BL/6J mice against a syngeneic melanoma.
Authors: Freedman V H , Calvelli T A , Silagi S , Silverstein S C
Published: June 2004

We have demonstrated that a murine cytotoxic peritoneal cell can be elicited by intraperitoneal immunization with heat-killed Mycobacterium bovis, strain Bacillus Calmette-Guérin (BCG). When these cells are injected together with cells of clone B(5)59 of B16 melanoma in a Winn-type transfer assay into syngeneic C57BL/6J mice, the tumorigenic potential of the melanoma is completely abrogated. Similarly, mice immunized intraperitoneally with dead BCG are protected against intraperitoneal challenge with a number of B16 melanoma cells sufficient to cause tumors in 100% of control mice. However, mice immunized intraperitoneally with dead BCG are not protected against tumor formation when B16 melanoma cells are injected subcutaneously. Co-injection of BCG-elicited peritoneal cells with B16 melanoma cells into nude or sublethally irradiated (650 rad) mice inhibits tumor formation in > 85% of the mice, indicating that additional participation of host bone marrow- or thymus-derived leukocytes is not required to eradicate the tumor implant. The effector cell in the BCG-induced peritoneal exudate is adherent and phagocytic and is a mononuclear phagocyte. Nonadherent lymphoid cells from the same BCG-induced peritoneal exudate and from thioglycollate-broth-elicited granylocytes and macrophages neither prevent nor delay B16 tumor formation.
Presence of highly conserved idiotypic determinants in a family of antibodies that constitute an intrastrain cross-reactive idiotype.
Authors: Lamoyi E , Estess P , Capra J D , Nisonoff A
Published: June 2004

It has been shown that A/J anti-p-azophenylarsonate antibodies that share a major cross-reactive idiotype (CRI) comprise a family of closely related, but nonidentical, molecules. Our results demonstrate that 12 of 14 monoclonal hybridoma products that express the CRI have in common at least one highly conserved idiotypic determinant. It is proposed that this reflects conservation of a portion of the amino acid sequence, presumably in hypervariable regions. That the conserved determinant(s0 are located in the region of the hapten-binding site is indicated by the ability of haptens to inhibit idiotype-anti-idiotype interactions involving the conserved, or public determinants.
Expression of an idiotype (Id-460) during in vivo anti-dinitrophenyl antibody responses. I. Mapping of genes for Id-460 expression to the variable region of immunoglobulin heavy-chain locus and to the variable region of immunoglobulin kappa-light-chain locus.
Authors: Dzierzak E A , Janeway C A , Rosenstein R W , Gottlieb P D
Published: June 2004

The genetic contro of the expression of an idiotype (Id-460) associated with the 2,4-dinitrophenyl (DNP)-binding BALB/c myeloma protein MOPC 460 was studied using congenic strains of mice. It was shown that the expression of high levels of Id-460 during secondary in vivo anti-DNP-ovalbumin responses was determined by genes governing immunoglobulin heavy-chain variable and kappa-light chain variable regions (V kappa). Appropriate alleles at both loci were required for the expression of Id-460. Genes in the major histocompatability complex and the X-linked immune deficiency gene found in strain CBA/N did not greatly affect Id-460 expression. The V kappa gene controlling Id-460 expression can be differentiated from Lyt-3, and it is the first instance in which expression of an idiotype subdivides the V kappa genes associated with the Lyt-3a allele. Although it is likely that the V kappa gene(s) involved are structural, the involvememt of a regulatory gene linked to the structural gene can not be excluded.
Defective B cell tolerance in adult (NZB X MZW)F1 mice.
Authors: Goldings E A , Cohen P L , McFadden S F , Ziff M , Vitetta E S
Published: June 2004

Hapten-specific tolerance was induced in vitro by trinitrophenyl-human gamma globulin (TNP32HGG) to a comparable degree in B cells from adult autoimmune (NZB X NZW)F1 (B/W) mice and normal BDF1, CBA/J, and DBA/1J mice. When a lower epitope density tolerogen (TNP7HGG) was used, B/W mice were significantly less sensitive than normal mice to the induction of B cell tolerance. This finding of defective B cell tolerance in adult B/W mice is consistent with previous reports that document other B cell abnormalities that may relate to the expression of autoimmune disease.
NZB cytotoxic lymphocyte responses. Kinetic analyses.
Authors: Huston D P , Steinberg A D
Published: June 2004

Cytotoxic lymphocyte (CTL) responses of unprimed NZB spleen cells peaked on day 4 of culture as did cells from primed NZB or BALB/c mice. In contrast, primary BALB/c and DBA/2 responses peaked on day 6 of culture. Thus, NZB CTL generation was similar to the accelerated in vitro generation of CTL from the spleen cells of alloantigen-primed NZB and BALB/c mice. To evaluate the kinetics of these CTL responses, multiple-time-point analyses were performed during the initial 90 min of the 51Cr-release assays. Analyses were done on days 4 and 6. On day 4, NZB CTL had an initial velocity of lysis slightly greater than that of BALB/c or DBA/2 CTL; however, it was far less than that of secondary NZB and secondary BALB/c CTL. These studies indicate that NZB mice can generate primary CTL responses at an accelerated rate. Such augmented primary responses are unique and may explain recently described abnormal NZB T cell recognition as well as resistance of NZB CTL to suppressor signals.
Monoclonal antibodies to guinea pig Ia antigens. II. Effect on alloantigen-, antigen-, and mitogen-induced T lymphocyte proliferation in vitro.
Authors: Burger R , Shevach E M
Published: June 2004

Four xenographic monoclonal antibodies to guinea pig Ia antigens were tested for their inhibitory effects on antigen-, alloantigen-, and mitogen-induced T cell proliferation. All four monoclonal antibodies reacted with strain 2 Ia antigens, and all four were capable of inhibiting the strain 13 against strain 2 mixed leukocyte reaction (MLR) by 50-70%; the two monoclonals that reacted with strain 13 Ia antigens were also capable of inhibiting the strain 2 against strain 13 MLR. In contrast, an analysis of the effects of a single monoclonal antibody on the responses to several antigens demonstrated a selective monoclonal pattern of inhibition in that the responses to some, but not all, antigens were inhibited. These results suggest that monoclonal antibodies react with different parts of Ia molecules that may have different functional roles and that certain parts of an Ia molecule participate in the presentation of certain antigens, whereas other regions of the same molecule present different antigens.
Immunoregulatory role of maternal idiotypes. Ontogeny of immune networks.
Authors: Wikler M , Demeur C , Dewasme G , Urbain J
Published: June 2004

Specific idiotypie can be induced in randomly chosen rabbits by preimmunization with anti-idiotypic antibodies (Ab2). Rabbits that synthesize anti-anti-idiotypic antibodies (Ab3) when injected with antigen produce antibodies that display idiotypic specificities that are also found on the starting idiotype. When female rabbits actively producing Ab3 are crossed with naive males, a significant proportion of the offsprings (approximately 40%) produce antibodies that were idiotypically cross-reactive with the starting idiotype, as compared to 3% of the controls. This conclusion was obtained using 5 female rabbits and their 32 surviving offspring. Maternal idiotypes have therefore strong immunoregulatory properties and influence the emergence of the available idiotypic repertoire.
Human prothymocytes. Membrane properties, differentiation patterns, glucocorticoid sensitivity, and ultrastructural features.
Authors: Galili U , Polliack A , Okon E , Leizerovitz R , Gamliel H , Korkesh A , Schenkar J G , Izak G
Published: June 2004

Thymic precursor cells (prothymocytes) comprise a large proportion of the fetal thymic cell population, but are less frequently encountered in the postnatal thymus, where they compose < 1% of the entire population. In the present study we attempted to characterize a number of properties of the prothymocytes obtained from human fetal thymic tissues after depletion of the E-rosette thymocyes on a Ficoll-Hypaque gradient. The prothymocytes are larger than the thymocytes and show a different nuclear chromatin pattern. This subset of cells lacks the E-rosetting and natural-attachment capacities and, unlike thymocytes, does not bind the lectin peanut agglutinin. Human prothymocytes are highly sensitive to the in vitro cytolytic effect of hydrocortisone, whereas the thymocytes are resistant. Long-term in vitro culture of prothymocytes resulted in the expression of thymocyte characteristics together with a burst of mitotic activity. Results of this study indicate that the rate of the prothymocyte proliferation is regulated by the small thymocytes present in the same suspension.
Macrophage variants in oxygen metabolism.
Authors: Damiani G , Kiyotaki C , Soeller W , Sasada M , Peisach J , Bloom B R
Published: June 2004

Whereas phagocytic cells from normal individuals have the capacity to kill ingested bacteria and parasites, those from patients with several uncommon genetic deficiency diseases are known to be defective in bactericidal activity. Studies on neutrophils of these patients have revealed fundamental defects in their ability to reduce molecular oxygen and metabolize it to superoxide anion, hydrogen peroxide, and oxygen radicals. In the present experiments, we describe a clone of a continuous murine macrophage-like cell line, J774.16, that, upon appropriate stimulation, activates the hexose monophosphate shunt, and produces superoxide anion and hydrogen peroxide. With nitroblue tetrazolium to select against cells capable of being stimulated by phorbol myristate acetate to reduce the dye to polymer--formazan--which is toxic fot cells, we have selected for variants that are defective in oxygen metabolism. Four of these subclones have been characterized and found to be lacking in the ability (a) to generate superoxide anion, as measured by cytochrome c reduction; (b) to produce hydrogen peroxide, as measured by the ability to form complex I with cytochrome c peroxidase; and (c) to be stimulated to oxidize glucose via the hexose monophosphate shunt. These variants appear to represent a useful model for studying the molecular basis for macrophage cytocidal activity.
Elimination of syngeneic sarcomas in rats by a subset of T lymphocytes.
Authors: Fernandez-Cruz E , Woda B A , Feldman J D
Published: June 2004

Established subcutaneous Moloney sarcomas (MST-1) of large size and long duration were eliminated from syngeneic rats by intravenous infusion of varying numbers of specific syngeneic effector T lymphocytes. Spleen cells from BN rats in which tumor had regressed were cultured in an in vitro mixed lymphocyte tumor cell culture (MLTC) to augment cytotoxicity of effector cells. In the MLTC a T cell subset was expanded in response to MST-1 antigens and transformed into blast elements. With these changes, there was an increase in the W3/25 antigen on the T cell surface, a decrease of W3/13 antigen, and an increase in the number of T cells with Ia antigens. The subset associated with elimination of established tumors was a blast T cell W3/25+, W3/13+, as detected by monoclonal antibodies to rat T antigens. The W3/25+ subset was poorly cytotoxic in vitro for MST-1 and apparently functioned in vivo as an amplifier or helper cell in the tumor-bearing host. The W3/25- population was a melange of cells that included (W3/13+, W3/25-) T cells, null cells, Ig+ cells, and macrophages, and was associated with enhancement of tumor in vivo, suggesting the presence of suppressor cells.
Human homologue of murine T200 glycoprotein.
Authors: Omary M B , Trowbridge I S , Battifora H A
Published: June 2004

We report the identification of the human homologue of murine T200 glycoprotein. Peptide-mapping experiments suggest that the structure of the glycoprotein is highly conserved between the two species. Many of the properties of human T200 homologue are similar to those of murine T200 glycoprotein: it is broadly distributed within the hematopoietic system but is not detectable on nonhematopoietic cells; there are also structural differences between the forms of the glycoprotein found on T and B lymphoblastoid cell lines. These results suggest the homologous glycoproteins may play similar functional roles in both species.
Effects of soluble immune complexes on Fc receptor- and C3b receptor-mediated phagocytosis by macrophages.
Authors: Griffin F M
Published: June 2004

The effects of ingestion of soluble immune complexes upon macrophage phagocytic function was studied. Ingestion of immune complexes severely impaired the macrophage's ability to ingest IgG-coated particles but did not alter its ability to interact with particles by means other than its Fc receptors. Treatment of macrophages that had ingested immune complexes with supernates containing the previously described lymphokine that augments macrophage complement receptor function failed to enhance the cells' interaction with either IgG-coated erythrocytes or zymosan particles but markedly enhanced their ability to phagocytize via their complement receptors. The possible significance of these findings in immunologically mediated inflammation is discussed.
Clonal analysis of F1 hybrid helper T cells restricted to parental or F1 hybrid major histocompatibility determinants.
Authors: Sproviero J F , Imperiale M J , Zauderer M
Published: June 2004

Antigen-specific major histocompatibility complex (MHC)-restricted helper T cell precursors were induced to proliferate in cultures of keyhole limpet hemocyanin-primed lymph node cells. Clones of F1 hybrid helper T cells were isolated in limiting-dilution cultures. Each positive culture at a limiting-dilution of lymph node cells gave rise to > 10 helper T cells with a single MHC-restricted specificity. This made it possible to independently assay specific helper activity of isolated clones in secondary cultures with B cells of diverse origin. Different clones with helper activity restricted to either parental or unique F1 hybrid MHC determinants were found to occur at approximately equal frequency. The results are discussed in relation to hybrid Ia specificities and dual-complementing MHC-linked Ir genes.
T lymphocyte-mediated suppression of myeloma function in vitro. III. Regulation of antibody production in hybrid myeloma cells by T lymphocytes.
Authors: Abbas A K , Burakoff S J , Gefter M L , Greene M I
Published: June 2004

To investigate the mechanisms by which T lymphocytes regulate myeloma function in vitro, the effects of regulatory T cells on antibody secretion by a hybrid myeloma cell line were examined. Suppressor T cells (Ts) specific for idiotypic determinants on M315 (IgA, lambda 2 anti-2,4-dinitrophenol and anti-2,4,6-trinitrophenol [TNP]) and MPC 11 (IgG2b, kappa) myeloma proteins inhibit antibody secretion by the appropriate parental myeloma cells. When cocultured with a hybrid cell line derived by fusion of MOPC 315 and MPC 11 myelomas, the idiotype-reactive Ts inhibit secretion of only the immunoglobulin (Ig) bearing the relevant idiotype. In contrast, syngeneic TNP-reactive cytolytic T lymphocytes (CTL) inhibit antibody secretion by TNP-binding MOPC 315 cells but not by MPC 11 cells in the presence of soluble TNP-keyhole limpet hemocyanin (KLH), and this inhibition probably represents a prelytic effect of the CTL. Such TNP-reactive CTL, in the presence of TNP-KLH, inhibit both IgA and IgG secretion by the MOPC 315-MPC 11 hybrid, which is consistent with a prelytic effect. Thus, myeloma hybrids are a useful tool for investigating the effector function of regulatory T cells. These results are discussed with reference to the mechanisms of action of regulatory T cells and their relevance to modulation of physiologic humoral immune responses.
Effects of blocking helper T cell induction in vivo with anti-Ia antibodies. Possible role of I-A/E hybrid molecules as restriction elements.
Authors: Sprent J
Published: June 2004

To examine the role of Ia antigens in controlling T cell activation in vivo, unprimed (CBA X B6)F1 (H-2k X H-2b) T cells were positively selected to sheep erythrocytes (SRC) for 5 d in irradiated F1 mice in the presence of large doses of anti-Iak antibody. With selection in the presence of broad-spectrum anti-Iak antibody (A.TH anti-A.TL antiserum), the activated T cells were markedly reduced in their capacity to collaborate with either B10.BR (I-Ak I-Bk I-Jk I-Ek I-Ck) (kkkkk) or B10.A(4R) (kbbbb) B cells but gave good helper responses with B10 (bbbbb) and (B10 X B10.BR)F1 B cells. Because there was no evidence for suppression, these findings were taken to imply that the anti-Iak antibody bound to Ia determinants on radioresistant macrophagelike cells of F1 host origin and blocked the activation of the IGk-restricted subgroup of F1 T cells but did not affect activation of the Iab-restricted T cell subgroup. Analogous experiments in which F1 T cells were selected to SRC in F1 mice in the presence of monoclonal anti-I-Ak antibody gave different results. In this situation, the reduction in T cell help for Iak-bearing B cells applied to B10.A(4R) B cells but not to B10.BR B cells. With selection of F1 T cells in B10.A(4R) mice, by contrast, anti-I-Ak antibody blocked T cell help for both B10.A(4R) and B10.BR B cells. These data suggested that genes telomeric to the I-A subregion were involved in controlling T cell activation and T-B collaboration. Because no evidence could be found that I-B through I-C determinants per se could act as restrictions elements, the working hypothesis for the data is that Iak-restricted T cells consist of two subgroups of cells: one subgroup is restricted by I-A-encoded molecules, whereas the other is restricted by I-A/E hybrid molecules encoded by two separated genes situated in the I-A and I-E subregions, respectively. The notion that A/E hybrid molecules serve as restriction elements is in line with the findings of other workers that these molecules can act as alloantigens and control responses to certain antigens under double Ir gene control.
Amyloid P-component is a constituent of normal human glomerular basement membrane.
Authors: Dyck R F , Lockwood C M , Kershaw M , McHugh N , Duance V C , Baltz M L , Pepys M B
Published: June 2004

Glomerular and other vascular basement membranes were found to contain an antigen that was immunochemically indistinguishable from serum amyloid P-component. There was no immunological cross-reactivity between antisera to serum amyloid P-component and to collagen types I, III, IV, or V. The amyloid P-component antigen was confined to the endothelial aspect, the lamina rara interna, of glomerular basement membrane. It could not be eluted by high-ionic-strength saline, EDTA, dithiothreitol, or either polar or nonpolar detergents, but was released into solution when isolated glomerular basement membrane was digested by highly purified bacterial collagenase. Most of these P-component molecules and their constituent polypeptide chains were of higher molecular weight and lower isoelectric point than serum amyloid P-component. These findings indicate that, as well as being a normal plasma protein and a universal constituent of amyloid deposits, P-component is also a normal matrix glycoprotein of basement membrane in which it is covalently linked to collagen and/or other matrix proteins. This may be relevant both to the pathogenesis of amyloidosis and to other aspects of physiology and pathology of basement membranes.
Role of accessory cells in B cell activation. III. Cellular analysis of primary immune response deficits in CBA/N mice: presence of an accessory cell-B cell interaction defect.
Authors: Boswell H S , Nerenberg M I , Scher I , Singer A
Published: June 2004

The effect of the X-linked CBA/N genetic defect on the ability of mice to generate primary responses to thymic-dependent and thymic-independent antigens was assessed by comparing the ability of abnormal (CBA/N x DBA/2)F1 male mice and normal (DBA/2 x CBA/N)F1 male mice to generate 2,4,6-trinitrophenyl (TNP)-specific plaque-forming cell responses to TNP-keyhole limpet hemocyanin (KLH), TNP-conjugated Ficoll (TNP-Ficoll), TNP-Brucella abortus (BA), and TNP-lipopolysaccharide (LPS). The reciprocal F1 combinations used in this study differ genetically only in the origin of their X chromosome, but differ immunologically in that (CBA/N x DBA/2)F1 male mice express all the CBA/N immune abnormalities, whereas (DBA/2 x CBA/N)F1 male mice are immunologically normal. Analysis of thymic-dependent responses to TNP-KLH revealed that abnormal F1 mice were capable of generating primary responses in vivo to high doses of TNP-KLH, but failed to generate responses to suboptimal doses of TNP-KLH that were still immunogenic for normal F1 mice. Furthermore, under limiting in vitro micro-culture conditions, the abnormal F1 mice failed to generate primary thymic-dependent responses to any dose of TNP-KLH, even though under the identical conditions normal F1 mice consistently responded to a wide antigen dose range. The cellular basis of the failure of abnormal F1 mice to respond in vitro to TNP-KLH was investigated by assaying the ability of purified populations of accessory cells, T cells, and B cells from these mice to function in responses to TNP-KLH. The results of these experiments demonstrated that helper T cells and antigen-presenting accessory cells from abnormal F1 mice were competent and functioned as well as the equivalent cell populations from normal F1 mice. Instead, the failure of CBA/N mice to generate primary in vitro responses to TNP-KLH was solely the result of a defect in their B cell population such that B cells from these mice failed to be triggered by competent helper T cells and/or competent accessory cells. Similarly, the failure of abnormal F1 mice to respond either in vivo or in vitro to TNP-Ficoll was not the result of defective accessory cell presentation of TNP-Ficoll, but was the result of the failure of B cells from these mice to be activated by competent TNP-Ficoll-presenting accessory cells. In contrast to the failure of B cells from abnormal F1 mice to be activated in vitro in response to either TNP-KLH or TNP-Ficoll, B cells from abnormal F1 mice were triggered to respond to TNP-BA and TNP-LPS, antigens that did not require accessory cell presentation. The specific failure of B cells fron abnormal F1 mice to be activated in responses that required antigen-presentation by accessory cells suggested the possibility that the X-linked CBA/N genetic defect resulted in B cell populations that might be deficient in their ability to interact with antigen-presenting accessory cells...
Dynamics of leukotriene C production by macrophages.
Authors: Rouzer C A , Scott W A , Hamill A L , Cohn Z A
Published: June 2004

A method for the radiochemical assay of LTC production by mouse peritoneal macrophages in vitro is presented. The method involves labeling macrophages in culture with [5,6,8,9,11,12,14,15-3H]20:4 followed by stimulation of arachidonic acid (20:4) release under the experimental conditions desired. Radiolabeled leukotriene C (LTC) is recovered from the culture medium by extraction and silicic acid chromatography in 40% yield with full retention of biological activity. Because this LTC is radiochemically pure, the quantity of LTC release may be estimated from the amount of radioactivity in the sample. Use of the radioassay to study parameters affecting LTC synthesis by macrophages indicated that the time course of LTC synthesis and its relationship to the dose of a phagocytic stimulus (zymosan) were very similar to those of prostaglandin (PG) release. LTC release was also similar to that of PG in that lower levels of both metabolites were produced by Corynebacterium parvum-elicited macrophages than by resident cells. Finally, LTC release was stimulated in response to a challenge with antigen-antibody complexes, but lower maximal levels were attained than those with zymosan. The data presented here are consistent with the hypothesis that challenge of macrophages with a phagocytic stimulus leads to the release of 20:4 by an inducible phospholipase. Cyclooxygenase and lipoxygenase then compete for the released 20:4, leading to the production of PG, hydroxyeicosatetraenoic acids, and LTC.
Lymphokine enhances the expression and synthesis of Ia antigens on cultured mouse peritoneal macrophages.
Authors: Steinman R M , Nogueira N , Witmer M D , Tydings J D , Mellman I S
Published: June 2004

Soluble products from antigen stimulated Trypanosoma cruzi-immune spleen cells enhanced the expression of Ia antigens on proteose-peptone-elicited mouse peritoneal macrophages (M phi). Acquisition of Ia paralleled M phi activation, previously shown to be mediated by this same source of lymphokine (LK). Expression of Ia and four other plasma membrane antigens was monitored by quantitative binding and radioautographic studies with 125I-monoclonal antibodies. Immune LK selectively enhanced expression of Ia and, to a lesser extent, H-2D relative to control LK from antigen-stimulated noninfected spleen. The levels of three other non-major histocompatibility complex (MHC) antigens, including the trypsin-resistant Fc receptor, were similar in cells exposed to both sources of LK. As little as 1% immune LK induced one-half maximal expression of Ia. Kinetic studies revealed that much of the Ia on freshly explanted peritoneal M phi was lost during the 1st d of culture. In the continued presence of immune LK, Ia was re-expressed on virtually all M phi by the 2nd and 3rd d. Alternatively, > 95% Ia negative populations were obtained by culturing the cells 3 d; then, addition of LK induced Ia on most cells within 1 d. Once induced, Ia persisted on the M phi surface for at least 2 d. [35S]methionine radiolabeling indicated that immune LK selectively increased radiolabeling of M phi Ia, again with other non-MHC-linked plasma membrane polypeptides as controls. LK-induced Ia-bearing M phi were tested as primary mixed leukocyte reaction stimulators. 1 x 10(5)-2 x 10(5) M phi did not stimulate 4.5 x 10(6) responding T cells, whereas 10(4) dendritic cells induced strong responses, as previously described. Because Ia-positive M phi do not actively sensitize T cells in a model immune response, we propose that M phi MHC products serve primarily as recognition sites for previously sensitized T cells, thereby enhancing T cell-mediated M phi activation.
Late clonal selection and expansion of the TEPC-15 germ-line specificity.
Authors: Fung J , Köhler H
Published: June 2004

The maturation of the antibody response to phosphorylcholine (PC) in neonatal BALB/c mice was studied. A T cell-independent class 1 1 PC-antigen, 3-(p-azophenyl phosphorylcholine)-N-acetyl-L-tyrosylglycylglycine lipopolysaccharide, was synthesized and used to immunize neonatal mice of different ages. The earliest anti-PC hemolytic plaque-forming response could be induced in 1-d-old neonates. Idiotype analysis on these early anti-PC antibodies showed that the response was not TEPC-15 dominant although TEPC-15-positive plaque-forming cells were detected. However, idiotype analysis of the anti-PC-LPS response in 7 d or older animals indicated that clonal dominance had been established. Similar results were obtained in splenic fragment culture with cells from neonatal livers and spleens. PC-specific precursors were detected in the liver of 1-d-old neonates, whereas the spleen of those animals contained no precursors for PC. Precursors for PC residing in the neonatal liver are not TEPC-15 dominant, whereas the splenic PC precursors of 5- to 6-day-old animals express the TEPC-15 idiotype dominatly. These findings demonstrate that during ontogeny PC-specific B cells appear before the TEPC-15 clone becomes dominant. Thus clonal dominance in the adult anti-PC response and late acquisition of the TEPC-15 specificity during ontogeny do not signify a particularly unique or direct relationship to the expression of genes encoded in the germline.
T cell hybrids with arsonate specificity. I. Initial characterization of antigen-specific T cell products that bear a cross-reactive idiotype and determinants encoded by the murine major histocompatibility complex.
Authors: Pacifico A , Capra J D
Published: June 2004

T cell hybrids have been constructed between the BW5147 thymoma cell line and A/J splenocytes from mice suppressed with the p-azophenylarsonte hapten. Three independently derived cloned lines have been chracterized. Each secretes or sheds a 62,000-dalton antigen-specific product bound by rabbit antisera directed against the arsonate cross-reactive idiotype. In addition, each of the antien-specific molecules contains determinants encoded within the I region of the murine major histocompatibility complex. Peptide mapping analysis indictes that, whereas these molecules are remarkably similar, each is individually distinct in primary structure. The availability of cloned T cell lines that produce antigen-specific idiotype-positive I region-containing products should facilitate a more thorough dissection of the interrelationships of T-B interctions in the arsonate idiotypic system.
Mechanisms of autoantibody production in autoimmune MRL mice.
Authors: Pisetsky D S , McCarty G A , Peters D V
Published: June 2004

The quantitative expression of anti-DNA and anti-Sm antibodies has been investigated in autoimmune MRL-lpr/lpr and MRL-+/+ mice. Anti-Sm antibodies were detected in sera from 21/23 lpr/lpr and 10/16 +/+ mice, with individual animals showing striking variation in the time-course and magnitude of this autoantibody response. The peak antibody levels of the responding animals of each substrain did not differ significantly. For anti-DNA antibody, a different pattern of responsiveness was observed. Individual animals of each substrain produced very similar responses in terms of the magnitude and time-course of serum anti-DNA antibody. The differences in the peak levels of the two substrains were highly significant, with lpr/lpr mice demonstrating a much greater anti-DNA antibody response than +/+ mice. In lpr/lpr mice tested for both autoantibody systems, serum anti-DNA and anti-Sm antibodies showed distinct time-courses. These studies indicate that anti-DNA and anti-Sm antibodies are expressed independently in MRL mice, with the expression of anti-DNA, but not anti-Sm antibody markedly influenced by the presence of the 1pr gene. A fundamental difference in the mechanisms involved in the generation of anti-DNA and anti-Sm antibodies is suggested by the quantitative pattern of the two responses.
Analysis of histocompatibility requirements for proliferative and helper T cell activity. T cell populations depleted of alloreactive cells by negative selection.
Authors: Shih W W , Matzinger P C , Swain S L , Dutton R W
Published: June 2004

T cell populations were prepared from donors immunized with hapten-carrier conjugates and were depleted of alloreactive cells by negative selection. This was accomplished by injection of the cells into H-2-disparate irradiated recipients and recovery from the thoracic duct after 18-40 h. The genetic requirements for the proliferative and helper activity of these populations was determined. The proliferative response to antigen presented on adherent, Thy-1-negative cells was determined, and a requirement for syngeneic antigen-presenting cells (APC) was demonstrated. The same T cells were assayed for their ability to give help to hapten primed B cells. It was shown that there was a requirement for syngeneic APC and for linked recognition of hapten and carrier determinants on the same molecule by the B cell and T cell. There was no requirement for the B cell to be H-2 compatible with the T cell. The requirement for linked recognition was taken as evidence that the responses in allogeneic combinations were not a result of positive allogeneic effects. Precisely comparable restrictions were found with positively selected cells.
Degradation of connective tissue matrices by macrophages. I. Proteolysis of elastin, glycoproteins, and collagen by proteinases isolated from macrophages.
Authors: Werb Z , Banda M J , Jones P A
Published: June 2004

We have investigated the ability of neutral and lysosomal enzymes of mouse macrophages to degrade the insoluble extracellular matrices secreted by smooth muscle cells, endothelial cells, and fibroblasts. Matrices produced by smooth muscle cells contained glycoproteins, elastin, and collagens, but matrices of endothelial cells and fibroblasts contained no elastin. Sequential enzyme digestion of residual matrix revealed that plasmin, a product of macrophage plasminogen activation, degraded 50-70% of the glycoprotein in the matrices but did not degrade the elastin or the collagens. Purified macrophage elastase degraded glycoprotein and elastin components but had no effect on the collagens. The rate of elastin degradation by macrophage elastase was decreased in the presence of the glycoproteins. In contrast, human granulocyte elastase effectively degraded the matrix glycoproteins, elastin, and, to a lesser extent, collagens, Mammalian collagenase degraded only collagens. Conditioned medium from resident and inflammatory macrophages, containing mixtures of the secreted proteinases, degraded the glycoprotein and elastin components of the matrices. However, conditioned medium was less effective in degrading matrix than comparable amounts of purified macrophage elastase because > 90% of the elastase in the medium was in a latent form. Inclusion of plasminogen in the assays accelerated degradation. In the presence of plasminogen, glycoproteins were degraded readily by medium from P388D1, pyran copolymer-, thioglycollate-, and periodate-elicited macrophages and, to a lesser extent, by medium from endotoxin-elicited and resident macrophages; medium from P388D1, thioglycollate-, and periodate-elicited macrophages was most effective in elastin degradation, and resident, endotoxin-elicited and pyran copolymer-elicited macrophages degraded almost no elastin. The macrophage cathepsins D and B degraded all the matrix components at an optimum pH of 5.5 and acted with the secreted neutral proteinases to degrade the connective tissue macromolecules to amino acids and oligopeptides. These data indicate that macrophages at inflammatory sites contain and secrete proteolytic enzymes that could degrade the extracellular matrix.
Bacteriophage control of antiphagocytic determinants in group A streptococci.
Authors: Spanier J G , Cleary P P
Published: June 2004

At least two genes have been shown to be required for the expression of the antiphagocytic M protein molecule in group A streptococci. Evidence for phage involvement in the expression of M protein is that: (a) M- cultures of bacteria can be converted to the M+ state (resistant to phagocytosis) upon lysogenization with appropriate bacteriophages; (b) without those bacteriophages the M- recipient culture could not be detected to revert to the M+ state, even under our most stringent selective conditions; and (c) stable M+ lysogens cured of their bacteriophages returned to the M- state. Immunochemical analysis of lysogenically converted M+ strains demonstrated that they contain precipitating and antiphagocytic determinants of the parental M-76 strain (CS110) rather than M-12 determinants expressed by the phage donor strain. This information strongly suggests that the M- strain CS112 possesses the structural gene for M protein, but that it remains predominantly unexpressed. Quantitation of the M antigen produced by these strains supports the observation that the M- phage-recipient strain possesses a small amount of extractable M antigen and that phage activates its synthesis by some unknown mechanism. Various possibilities to account for the phage requirement in M protein synthesis and its role in the transition between M+ and M- states are discussed.
Production of predominantly polymeric IgA by human peripheral blood lymphocytes stimulated in vitro with mitogens.
Authors: Kutteh W H , Koopman W J , Conley M E , Egan M L , Mestecky J
Published: June 2004

Human peripheral blood lymphocytes (PBL) were cultured for various time periods (up to 8 d) in the presence of pokeweed mitogen (PWM), lipopolysaccharide, or Epstein-Barr virus. Cell-free supernates were fractionated on a standardized ultrogel AcA 22 column and the proportion of polymeric and monomeric IgA was determined by radioimmunoassay. The results demonstrate that PBL stimulated with these mitogens produce IgM and IgG with molecular characteristics identical to those found in serum, but that the IgA produced is predominantly of the polymeric type. To prove that this IgA represented disulfide bond-linked polymers rather than aggregated monomers, we have demonstrated that the high molecular weight IgA (a) maintains its polymeric form upon treatment with acidic buffers, (b) contains J chain, a glycoprotein associated only with polymeric immunoglobulins, and (c) dissociates to the monomeric form upon reduction of disulfide bonds. After 1 wk in culture, approximately 60% of the PWM-stimulated cells that contained IgA were positive for IgA2, whereas 40% were IgA1 positive as determined by immunofluorescence. Therefore, peripheral blood contains a population of lymphocytes with the potential to display, after appropriate stimulation and differentiation, characteristics similar to IgA cells found in external secretory tissues. The demonstration of the presence of such cells in the peripheral circulation suggests that these cells are precursors of IgA-producing plasma cells with the potential to populate mucosal tissues.
Systemic tolerance and secretory immunity after oral immunization.
Authors: Challacombe S J , Tomasi T B
Published: June 2004

Diminished systemic immune reaction after ingestion of antigen has been reported in several animal models. Conversely, it has been reported recently that oral immunization may lead to the production of secretory antibodies. To determine whether these events could occur concurrently, CBA/J mice were immunized intragastrically with varying doses of ovalbumin (OVA) and Streptococcus mutans. After 7 d, the animals were challenged systemically with antigen in complete adjuvant and 8 d later serum and saliva taken, and the draining lymph nodes assayed for a proliferative response. Intragastric doses of 1 mg OVA or 10(9) S. mutans led to significant suppression of the proliferative response, and intragastric doses of 10 mg OVA or 2.5 X 10(9) S. mutans led to the production of detectable salivary antibodies using hemagglutination. Serum antibodies were not detected after intragastric administration of OVA or S. mutans. Suppression of the proliferative response could be detected from 2-60 d after intragastric administration of OVA, and 2-21 d after S. mutans. Prior intragastric immunization with heterologous antigens did not suppress the response to OVA or S. mutans. Transfer of 40 X 10(6) mesenteric lymph node cells from mice given 20 mg OVA or 10(9) S. mutans led to suppression of the proliferative response in syngeneic recipients. Salivary antibodies wer removed by absorption with anti-IgA, but not anti-IgG or IgM, indicating that they were of the IgA class. It appears that intragastric administration of soluble or particulate antigens in mice may lead to the concurrent induction of salivary antibodies and systemic suppression.
In vitro generation of cytotoxic lymphocytes against radiation- and radiation leukemia virus-induced tumors. III. Suppression of anti-tumor immunity in vitro by lymphocytes of mice undergoing radiation leukemia virus-induced leukemogenesis.
Authors: Yefenof E , Meidav A , Kedar E
Published: June 2004

Adult C57BL/6 mice exposed to fractionated irradiation or inoculated with the radiation leukemia virus (RadLV), develop high incidence (80-100%) of lymphatic leukemias within 3-6 mo. RadLV-induced lymphomas can elicit cytotoxic responses in vitro in lymphocytes of preimmunized syngeneic mice, a reaction that is dependent on the expression of membrane-associated viral antigenicity. As soon as 5 d after RadLV inoculation, and during the entire leukemogenic process, suppressor T cells are detectable in the spleen that are capable of specifically abrogating generation of syngeneic anti-tumor cytotoxic cells in vitro. Mice exposed to fractionated x irradiation do not develop suppressor cells and their splenocytes may be stimulated in vitro to generate cytotoxicity toward RadLV-induced leukemias. These findings suggest that although RadLV has been isolated from radiation-induced leukemias, x-ray- and RadLV-induced leukemogenesis do not seem to involve a common viral etiology, and that induction of suppressor cells during RadLV leukemogenesis may be essential for tumor progression.