bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence indicating independent assortment of framework and complementarity-determining segments of the variable regions of rabbit light chains. Delineation of a possible J minigene.
Authors: Kabat E A , Wu T T , Bilofsky H
Published: June 2004

Amino acid sequences of rabbit light chains show considerable evidence of independent assortment of framework (FR) and complementarity-determining (CDR) segments. This suggests that they are coded for by independent genetic units (minigaenes) and that individual light chains are assembled somatically by recombining these units. Identical FR sets with multiple members generally comprise chains with different specificities, whereas identical CDR sets tend to have chains of a single specificity. A J segment, which, by analogy with mouse light chains, is made up of the last two residues of CDR3 plus all of FR4, contained 18 different sets and could contribute to diversity generated by CDR3. The longest segment, FR3, had a very large number of sets. Evidence is presented showing that the number of sets could be substantially reduced by permitting FR3 to be formed by two independently assorting segments comprising residues 57-68 and 69-88.
Role of self and foreign antigenic determinants in allogeneic and self-restricted cytotoxic T cell recognition.
Authors: Levy R B , Gilheany P E , Shearer G M
Published: June 2004

Murine spleen cells were sensitized in vitro to H-2 disparate allogeneic spleen cells and assayed on syngeneic target cells conjugated with the trinitrophenyl (TNP)-self or the fluorescein isothiocyanate (FITC)-self haptens, or on syngeneic target cells expressing the male H-Y antigen (H-Y self). The results indicated that allo-induced cytotoxic T lymphocytes (CTL) contained effectors that lysed both hapten-self but not H-Y self targets. Furthermore, it was demonstrated that separate populations of those allogeneic CTL were responsible for the lysis of TNP-self and FITC-self targets. This study also showed that cytotoxic effectors generated against the H-Y antigen with lytic activity equal to or greater than that of an allogeneically induced CTL response were unable to lyse hapten-self targets. These findings provide the first evidence that H-2 alloantigens may be unique in their ability to induce effectors that lyse hapten-conjugated autologous targets. These observations are discussed with respect to the self and foreign antigenic determinants involved in allogeneic and self-restricted CTL models.
Quantitative studies on T cell diversity. I. Determination of the precursor frequencies for two types of streptococcus A-specific helper cells in nonimmune, polyclonally activated splenic T cells.
Authors: Eichmann K , Falk I , Melchers I , Simon M M
Published: June 2004

A limiting-dilution system is described that makes use of T cell growth factor T cell expansion and allows the determination of precursor frequencies for various regulatory and effector T cells in nonimmune, polyclonally, or specifically activated T cell populations. Two different sets, a frequent and a rare set, of T helper cell precursors with specificity for trinitrophenyl-group A streptococcal vaccine, could be identified: the frequent set is of the Lyt-123 phenotype, and is present at frequencies of from 1/1,000 to 1/6,000 splenic T cells. It is only active at low cell numbers, whereas it is completely inactivated at greater cell numbers, presumably by suppressor T cells of lower frequency but greater potency. The rare set is of the Lyt-1 phenotype, is present at frequencies of from 1/10,000 to 1/70,000, and is not sensitive to suppressor cells present within the tested cell numbers. We suggest that the frequent set contains primiary helper cell precursors, whereas the rare set contains helper T memory cells preselected by previous exposure to other antigens. The results are discussed with respect to other reports on the involvement of more than one set of helper cells in antibody production.
Evidence for a new segregant series of B cell antigens that are encoded in the HLA-D region and that stimulate secondary allogenic proliferative and cytotoxic responses.
Authors: Shaw S , Johnson A H , Shearer G M
Published: June 2004

Five new histocompatibility antigens, designated secondary B cell or (SB) antigens, have been identified by secondary allogeneic proliferative and cytotoxic responses. The reagents used to define the SB antigents are lymphocytes primed between donors matched for all known HLA antigens. The SB antigens stimulate weak primary allogeneic proliferative responses (a mean relative response of 8%) but strong secondary proliferative responses. Strong secondary cell-mediated cytotoxicity is generated against target antigens that are distinguishable from the SB antigens defined by proliferation. Studies by direct lysis and by cold-target inhibition indicate that these target antigens are preferentially expressed on B cells relative to T cells. The SB antigens segregate with HLA, and the gene(s) encoding the SB1, 3, and 4 antigens maps centromeric to HLA-B. The SB antigens are major histocompatibility antigens not only because they are encoded by major histocompatibility complex (MHC) genes, but also by the functional criteria that the proliferative and cytotoxic responses to SB antigens are not restricted by HLA-DR or HLA-A,-B. Parallel studies of the SB antigens and the DR antigens with respect to: (a) their preferential expression on B cells, (b) their function in secondary allogeneic proliferative and cytotoxic respones, and (c) the location of their structural gene within the MHC. However, the SB antigens and the DR antigens are clearly distinct antigens, because population studies indicate that they can occur independently, and family studies indicate that specific SB antigens segregate with HLA haplotypes having different D and DR specificities. Our data are consistent with the hypotheses that the SB antigens are a new segregant series of B cell alloantigens, and that the SB gene and the DR gene derive from a duplicated ancestral gene.
Cellular basis of graft versus host tolerance in chimeras prepared with total lymphoid irradiation.
Authors: Gottlieb M , Strober S , Kaplan H S
Published: June 2004

BALB/c mice given allogeneic (C57BL/Ka) bone marrow cells after toal lymphoid irradiation become stable chimeras approximately 80% donor-type and 20% host-type cells in the spleen. The chimeras doe not develop graft vs. host disease (GVHD). Purified cells of C57BL/Ka origin from the chimeras mediated GVHD in lightly irradiated C3H (third party), but not in BALB/c (host-strain) mice. Thus graft vs. host tolerance in the chimeras could not be explained by complete immunodeficiency of donor-type cells, serum blocking factors, or suppressor cells of host (BALB/c) origin. Clonal deletion or suppression of lymphocytes reactive with host tissues remain possible explanations. The transfer of donor-type chimeric spleen cells to BALB/c recipients given 500-550 rad whole-body irradiation WBI led to stable mixed chimerism in approximately 50% of recipients. The cells were presumably acting as tolerogens because similarly irradiated BALB/c mice given (BALB/c X C57BL/Ka)F1 spleen or bone marrow cells also became stable mixed chimeras.
Growth of factor-dependent hemopoietic precursor cell lines.
Authors: Dexter T M , Garland J , Scott D , Scolnick E , Metcalf D
Published: June 2004

Cell lines have been produced from long-term cultures of mouse bone marrow that require a factor, present in WEHI-3 conditioned medium (CM) or in spleen CM, for their sustained growth. The cell lines were obtained from nonvirus-treated cultures, are nonleukemic, maintain a normal karyotype, and form colonies showing granulocyte maturation when plated in soft agar. Granulocyte/macrophage (GM) colony-stimulating factor is not the inductive moiety involved in the maintenance of proliferation of these cells. It is suggested that the cell lines represent a self-renewing population of cells ancestral to GM colony-forming cells, which may be responding to a hitherto unrecognized regulator.
Systemic immune unresponsiveness induced in adult mice by anterior chamber presentation of minor histocompatibility antigens.
Authors: Streilein J W , Niederkorn J Y , Shadduck J A
Published: June 2004

The ability to introduce carefully controlled numbers of viable cells into the anterior chamber of mouse eyes made it possible to examine the interrelationship between presentation of antigens into the anteior chamber and into conventional body sites and their synergistic/antagonistic effects on the immune system. P815 mastocytoma (DBA/2; H-2d) cells are syngeneic with BALB/c hosts at the major histocompatibility locus, but differ at multiple minor histocompatibility loci. When P815 cells were injected subcutaneously, they were rejected by BALB/c recipients who became specifically immune. By contrast, when P815 cells were injected intracamerally, they grew progressively into massive intraocular tumors; moreover, these BALB/c hosts proved subsequently unable to reject subcutaneously injected P815 cells, and, more impressively, failed to reject DBA/2 skin allografts placed orthotopically. Minor histocompatibility antigens, presented first through the anterior chamber of mouse eyes, elicit a suppressive rather than an aggressive host immune response that protects cells that bear these antigens from a destructive alloimmune reaction at both intracameral and systemic sites.
Selective turnover and shedding of H-2K and H-2D antigens is controlled by the major histocompatibility complex. Implications for H-2-restricted recognition.
Authors: Emerson S G , Murphy D B , Cone R E
Published: June 2004

Lactoperoxidase-catalyzed cell surface radioiodination and incorporation of [3H]-leucine were employed to radiolabel H-2K and H-2D antigens of murine spleen cells. The fate of H-2 antigens was monitored by in vitro culture of labeled cells and isolation of labeled antigens from detergent lysates of the cells and culture supernates obtained at different times during culture. H-2Kk antigens were found to be rapidly turned over and shed by CBA/J cells, whereas the turnover of H-2Dk antigens was extremely slow. Analysis of the membrane residence times of surface-labeled H-2K and H-2D antigens on spleen cells from various H-2-congenic and -recombinant strains demonstrated variations in the shedding rates of H-2K and H-2D antigens, which were controlled by genes mapping in the major histocompatibility complex. These variations show a striking correlation with published, genetically controlled quantitative variations in the cytotoxic response of T lymphocytes to chemically modified or virus-infected syngeneic cells.
Immunogenic variants obtained by mutagenesis of mouse mastocytoma P815. II. T lymphocyte-mediated cytolysis.
Authors: Boon T , Van Snick J , Van Pel A , Uyttenhove C , Marchand M
Published: June 2004

Tumor cell variants that were rejected by syngeneic mice (tum-) were obtained from mastocytoma P815 by mutagenesis (as described in the accompanying report (13). A considerable T lymphocyte-mediated lysis was observed upon incubation of these tum- variants with peritoneal exudate cells collected a few days after an intraperitoneal challenge of immune animals. Spleen cells from these animals were cytolytic after stimulation in vitro with the immunizing variant. New antigens, absent from the original P815 tum+ cells, were detected on 15 of the 21 tum- variants that were tested. All these antigens appeared to be different. No new antigen was detected on any of 10 mutagenized P815 clones that had retained their ability to form tumors. We compared the evidence obtained in vivo and in vitro for the presence of specific antigens on five tum- variants. Three variants were shown both in vivo and in vitro to carry an individual antigen. One showed no specificity either in vivo or in vitro. However, for one variant, no specificity was observed in vivo, although cytolysis tests demonstrated the existence of a singular antigenic specificity.
Antigen- and receptor-driven regulatorymechanisms. The failure of idiotype- coupled spleen cells to induce unresponsiveness in animals lacking the appropriate VH genes is caused by the lack of idiotype-matehed targets
Authors: Sy M-S , Dietz MH , Nisonoff A , Germain RN , Benacerraf B , Greene MI
Published: June 2004

A/J anti-p-azobenzenearsonate (ABA) antibodies bearing cross-reactive idiotypic (CRI) determinants, when coupled to spleen cells and then injected intravenously into naive animals, stimulate suppressor T cell (Ts) responses. Moreover, previous studies have demonstrated that the ability of such idiotype-coupled spleen cells to induce immune unresponsiveness to subsequent immunization with ABA-coupled spleen cells is linked to Igh-1 genes. Thus, CRI bearing antibodies from A/J mice, when conjugated to normal BALB/c spleen cells in vitro and then injected intravenously to syngeneic BALB/c mice, failed to induce tolerance in these animals. However, spleen cells taken from these animals transferred significant degrees of suppression to Igh-1 congenic C.AL-20 but not to H-2 congenic, Igh-1 distinct B10.D2 mice. Therefore, the failure of CRI-coupled spleen cells to induce suppressor cell- mediated unresponsiveness in animals unable to express the appropriate VH genes (i.e. BALB/c and B10.D2) appears to be caused by the lack of idiotype- matched targets. The notion that the ability to express certain Vn genes in the recipient animal is a prerequisite for suppressor cell function was further supported by the observation that suppressor cells induced in C.AL-20 mice failed to transfer any degree of suppression to BALB/c mice. The ability to transfer suppression from BALB/c mice to C.AL-20 mice is a T cell- dependent phenomenon, since in vitro treatment with anti-Thy 1.2 antiserum and complement completely abrogated suppressor cell function. Furthermore, these suppressor T cells are antigen specific and can be enriched on idiotype-coated petri dishes, indicating they possess anti-idiotypic receptors. Therefore, appropriate anti-idiotype and idiotype interaction is essential for the manifestation of suppressor T cell function in ABA-specific suppressor pathways.
The role of H-2-linked genes in helper T cell function. VII. Expression of I region and immune response genes by B cells in bystander help assays.
Authors: Marrack P , Kappler J W
Published: June 2004

The mode of action by bystander helper T cells was investigated by priming (responder X nonresponder) (B6A)F1 T cells with poly-L-(Tyr, Glu)-poly-D,L-Ala--poly-L-Lys [(TG)-A--L] and titrating the ability of these cells to stimulate an anti-sheep red blood cell (SRBC) response of parental B cells and macrophages in the presence of (TG)-A--L. Under limiting T cell conditions, and in the presence of (TG)-A--L, (TG)-A--L-responsive T cells were able to drive anti-SRBC responses of high-responder C57BL/10.SgSn (B10) B cells and macrophages (M0), but not of low-responder (B10.A) B cells and M0. Surprisingly, the (TG)-A--L-driven anti-SRBC response of B10.A B cells was not restored by addition of high-responder acessory cells, in the form of (B6A)F1 peritoneal or irradiated T cell-depleted spleen cells, or in the form of B10 nonirradiated T cell-depleted spleen cells. These results suggested that (TG)-A--L-specific Ir genes expressed by B cells controlled the ability of these cells to be induced to respond to SRBC by (TG)-A--L-responding T cells, implying that direct contact between the SRBC-binding B cell precursor and the (TG)-A--L-responsive helper T cells was required. Analogous results were obtained for keyhold limpet hemocyanin (KLH)-driven bystander help using KLH-primed F1 T cells restricted to interact with cells on only one of the parental haplotypes by maturing them in parental bone marrow chimeras. It was hypothesized that bystander help was mediated by nonspecific uptake of antigen [(TG)-A--L or KLH] by SRBC-specific b cells and subsequent display of the antigen on the B cell surface in association with Ir of I-region gene products, in a fashion similar to the M0, where it was then recognized by helper T cells. Such an explanation was supported by the observation that high concentrations of antigen were required to elicit bystander help. This hypothesis raises the possibility of B cell processing of antigen bound to its immunoglobulin receptor and subsequent presentation of antigen to helper T cells.
Alloreactive and H-2-restricted Lyt 23 cytotoxic T lymphocytes derive from a common pool of antecedent Lyt 123 precursors.
Authors: Hardt C , Pfizenmaier K , Röllinghoff M , Klein J , Wagner H
Published: June 2004

If the collaborative requirement of Lyt 1 T helper cells is bypassed by the Lyt 1 T cell-derived mediator of T help, termed Il-2, upon antigenic stimulation, PNA+ Lyt 123 thymocytes differentiate into either alloreactive or H-2-restricted PNA- Lyt 23 cytotoxic effector cells. Along the differentiation pathway from Lyt 123 leads to 23 effector cells, cytolytic activity is carried out by T cells that still express the Lyt 123 phenotype. The data establish that Lyt 23 CTL are produced by differentiation from antecedent Lyt 123 cells.
Novel surface antigen expressed on dividing cells but absent from nondividing cells.
Authors: Judd W , Poodry C A , Strominger J L
Published: June 2004

Radioimmunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to study the distribution on human lymphoid cells of a previously undescribed surface antigen recognized by several heteroantisera. A glycoprotein with a 90,000 mol wt (under reducing conditions) was detected on all cell lines tested including T, B, null, and myeloid cell lines, although the amount of antigen present varied considerably. The antigen was absent from normal peripheral blood lymphocytes (PBL), B and T cells, monocytes, granulocytes, thymocytes, and erythrocytes. After stimulation with lectins or allogeneic B cells, the antigen was induced on PBL T cells. A limited number of leukemic T cells tested all expressed the antigen, as did melanoma cell line and human embryonic lung fibroblasts. Hence, the antigen was present only on dividing lymphoid cells and absent from nondividing cells, but was also present on the two examples of dividing non-lymphoid cells tested. Under nonreducing conditions, the 90,000-mol wt band normally present disappeared to be replaced by another at approximately 200,000 mol wt. The glycoprotein bound to lectins from lentil and ricin, but not to wheat germ agglutinin. It could be readily labeled metabolically by [35S]methionine or by surface iodination, and appeared to be a major membrane protein on some cell lines.
Serological identification and cellular distribution of three F9 antigen components.
Authors: Morello D , Condamine H , Delarbre C , Babinet C , Gachelin G
Published: June 2004

Using an affinity chromatography technique, IgM, IgG1, IgG2a,b anti-F9 antibodies have been isolated from the anti-F9 serum; their activities have been analyzed by IF test on a variety of cell types, teratocarcinoma-derived cell lines, and embryos. The anti-F9 antibodies react with at least three independent antigenic determinants not expressed on the same cell types, and that appear along different time-course during embryonic development.
Limited proteolysis by macrophage elastase inactivates human alpha 1-proteinase inhibitor.
Authors: Banda M J , Clark E J , Werb Z
Published: June 2004

Inflammatory mouse peritoneal macrophages secrete a metalloproteinase that is not inhibited by alpha 1-proteinase inhibitor. This proteinase, macrophage elastase, recognizes alpha 1-proteinase inhibitor with macrophage elastase does not involve a stable proteinase-inhibitor complex and results in the proteolytic removal of a peptide of apparent molecular weight 4,000-5,000 from the inhibitor. After degradation by macrophage elastase, alpha 1-proteinase inhibitor is no longer able to inhibit human granulocyte elastase, a serine proteinase implicated in the pathogenesis of emphysema. Macrophage elastase apparently does not degrade human granulocyte elastase-alpha 1-proteinase inhibitor complexes or release active granulocyte elastase from these complexes. The ability of macrophage elastase to degrade alpha 1-proteinase inhibitor is inhibited by EDTA and alpha 2-macroglobulin.
Antigen-specific helper T cells required for dominant production of an idiotype (THId) are not under immune response (Ir) gene control.
Authors: Bottomly K , Maurer P H
Published: June 2004

Responder and nonresponder mice primed with poly-(L-glutamic acid,L-lysine,L-phenylalanine) (GLPhe), the response to which is under the control of immune response (Ir) genes, were used as a source of both types of helper T cells required for a T15 idiotype dominated T-dependent anti-phosphorylcholine (PC) response. It was found that the activity of one of the helper T cells needed for an anti-PC response was under major histocompatibility complex (MHC)-linked Ir gene control, and only GLPhe-primed responder mice could be used as a source of these cells. These T cells (ThMHC) whose presence is required for in vivo T-B collaboration are found in normal and anti-mu-treated mice, and their activity depends on the hapten being physically linked to the carrier molecule. By contrast, the activity of the second helper T cell (ThId) required for a T15-dominated anti-PC response was present in both GLPhe-primed responder and nonresponder mice. The ThId cell set that is missing or deficient in anti-mu treated mice can be restored by the addition of T cells from normal, carrier-primed donors and restimulating with the priming carrier. When T cells from GLPhe-primed donors are used as a source of ThId cells, both responder and nonresponder donors provide helper cells capable of inducing syngeneic B cells to produce a T15 dominated anti-Pc response. These results are interpreted to suggest that idiotype recognizing helper T cells (ThId) recognize antigen independent of known Ir gene products.
Maternally transmitted target antigen for unrestricted killing by NZB T lymphocytes.
Authors: Fischer Lindahl K , Bocchieri M , Riblet R
Published: June 2004

A new target antigen for unrestricted killing was defined by NZB T lymphocytes which were immunized and restimulated with H-2-identical BALB/c spleen cells. These effector cells killed nearly all target cells tested, irrespective of their H-2 type, but did not kill NZB target cells. The response was shown to have three major components: unrestricted killing specific for Qed-1b, H-2d-restricted killing specific for minor histocompatibility antigens, and unrestricted killing specific for a new antigen, Mta. Mta is present on normal and mitogen-stimulated T and B lymphocytes and on several tumor lines. It was found on cells from 26 mouse strains tested, including two substrains of NZB, representing 9 different H-2 types and 14 different non-H-2 backgrounds. Analysis of the NX8 recombinant inbred lines (derived from Mta-NZB/Icr and Mta+C58/J parents) suggested that Mta is maternally transmitted. This was confirmed by typing of reciprocal F1 hybrids and backcrosses between positive and negative strains: Mta+ females bear Mta+ offspring and Mta- females Mta- offspring, irrespective of the phenotype of the males.
Activation of macrophages for enhanced release of superoxide anion and greater killing of Candida albicans by injection of muramyl dipeptide.
Authors: Cummings N P , Pabst M J , Johnston R B
Published: June 2004

The adjuvant muramyl dipeptide (MDP) has been shown to affect a number of macrophage functions in vitro. We studied the effect of subcutaneous injection of MDP into mice. Cultured peritoneal macrophages from treated mice displayed increased spreading, total cell protein, and specific activity of beta-glucosaminidase a constituent of macrophage lysosomes, and of lactate dehydrogenase. Generation of superoxide anion (O2-) by MDP-treated macrophages stimulated by contact with phorbol myristate acetate was enhanced by over fivefold to levels achieved by macrophages from bacillus Calmette-Guérin-infected mice. The enhancement in stimulated O2- release was noted by 1 h after injection of MDP, peaked by 3 h, and remained high for at least 48 h. Priming for enhancement of O2- release by MDP was similar in athymic nude mice and in normal littermates, suggesting that mature T lymphocytes are not involved in this MDP effect. Priming for enhanced stimulated O2- release, and morphologic and enzymic changes, were not achieved by injection of the D-D stereoisomer of MDP. Phagocytosis of Candida albicans was only slightly greater by macrophages from mice give MDP, but MDP-stimulated cells killed two times more C. albicans in vitro than did cells from untreated animals. When MDP was given 18 h before, simultaneously with, or 24 h after lethal infectious challenge with C. albicans, treated mice were protected compared with controls. These results suggest that injection of MDP effectively and rapidly activates macrophages in the recipient animal. This agent should serve as an important probe of macrophage physiology and, perhaps ultimately, as a means of enhancing host defense in humans.
Biochemical and biological characterization of lymphocyte regulatory molecules. V. Identification of an interleukin 2-producing human leukemia T cell line.
Authors: Gillis S , Watson J
Published: June 2004

To isolate a stable tumor cell line capable of producing human interleukin 2 (IL-2; formerly referred to as T cell growth factor), 16 human T and B leukemia cell lines were screened for constitutive and mitogen-stimulated IL-2 production. We found that the T cell leukemia line designated Jurkat-FHCRC produced > 200 U/ml of IL-2 activity after a 24-h stimulation with T cell mitogens. Peak mitogen-induced IL-2 activity was found in supernates harvested from 24-h Jurkat-FHCRC cell cultures stimulated with either 1% phytohemagglutinin or 20 microgram/ml concanavalin A. Addition of the fatty acid derivative phorbol myristate acetate to mitogen-stimulated cultures increased Jurkat-FHCRC IL-2 production to concentrations > 400 U/ml. IL-2 activity observed in such cases represented between 100--300 times that produced in conventional cultures of mitogen- or alloantigen-stimulated normal human peripheral blood or splenic lymphocytes. Jurkat-FHCRC-derived conditioned medium demonstrated equal capacity to promote the sustained in vitro proliferation of either murine or human activated T cell lines confirming the ability of Jurkat-FHCRC cells to produce human IL-2. These studies identify a new source of human IL-2 and establish a valuable reagent for the isolation and further molecular characterization of this immunoregulatory molecule.
Helper and killer T cells do not express B cell immunoglobulin joining and constant region gene segments.
Authors: Kronenberg M , Davis M M , Early P W , Hood L E , Watson J D
Published: June 2004

We have analyzed four kinds of T cells for rearrangement and expression of immunoglobulin genes. These cells include: (a) whole thymus; (b) WEHI-22, a T-cell lymphoma; (c) HT-1, an major histocompatibility complex-restricted T helper line; and (d) CTLLi6, an H-2 alloreactive killer cell line. None of the B-cell joining and constant gene segments are rearranged in the T cells. The monoclonal cells do not express any C kappa, C lambda, Cmu or C alpha RNA species. Small amounts of C kappa, C alpha, and Cmu sequences are present in RNA prepared from the thymus, although the significance of this RNA for T-cell antigen receptor synthesis is uncertain. The data support the hypothesis that expression of B-cell joining and C gene segments is unnecessary for T-cell helper and T-cell killer activity.
Cytotoxic T lymphocyte responses by chimeric thymocytes. Self-recognition is determined early in T cell development.
Authors: Kruisbeek A M , Hodes R J , Singer A
Published: June 2004

In this study the cytotoxic T lymphocyte (CTL) recognition pattern of thymocytes from recently reconstituted parent leads to F1 and F1 leads to parent radiation bone marrow chimeras was investigated. Chimeric thymocytes were entirely of donor origin approximately 4 wk after irradiation and reconstitution but were not capable of autonomously generating either alloreactive or trinitrophenyl (TNP)-modified-self-reactive CTL responses. However, in the presence of interleukin-2 (I1-2), the the putative T helper cell product, CTL could be generated in vitro by thymocytes from recently reconstituted chimeras. Experiments with thymocytes from A leads to A X B and A X B leads to A chimeras revealed the following: (a) thymocytes from both types of chimeras were nonreactive to either A or B parental major-histocompatibility complex (MHC) determinants even though they were alloreactive to third-party stimulator cells; and (b) thymocytes from these chimeras were restricted to the recognition of TNP in association with MHC determinants syngeneic to the chimeric host. Thus, these experiments demonstrate that even at the earliest time CTL effectors of donor origin from the thymuses of chimeras can be studied, their self-receptor repertoire has already been restricted to recognition of host MHC determinants. These results support the concept that the host environment influences the self-recognition capacity of T cells at the pre- or intrathymic stage of differentiation.
Tumorigenicity and lysis by natural killers.
Authors: Collins J L , Patek P Q , Cohn M
Published: June 2004

Detailed analysis of the natural killer (NK) activity directed at nontumorigenic cell lines and their transformed tumorigenic derivatives has revealed a paradox. On the one hand, a correlation has been found between the tumorigenic potential of chemically transformed fibroblast cell lines and their sensitivity to NK cells in vitro. Nontransformed cells (N-type cell lines) and cells tumorigenic in normal mice (C-type cell lines) are resistant to NK-mediated lysis. In contrast, cell lines that are tumorigenic in ATxFL mice (these mice are very low in NK activity), but not in normal mice (I-type cell lines) are sensitive to NK-mediated lysis. These findings support the concept that NK activity is involved in host surveillance against tumors. On the other hand, NK-resistant fibroblasts, whether taken directly form animals or derived as tumorigenic or nontumorigenic cell lines, compete with NK-sensitive target cells to inhibit their lysis by NK effectors. Not only are both NK-sensitive and -resistant cells recognized by NK effectors but both receive lytic signals from NK effector cells. Target cell resistance is a result of a protein synthesis-dependent mechanism that prevents lysis such that in the presence of inhibitors of protein synthesis all fibroblasts tested are NK sensitive. Those fibroblasts that are normally sensitive to NK-mediated lysis must be deficient in their ability to produce or respond to this counterlytic mechanism. These findings are in contrast with the general findings when lymphoid cells are studied as NK targets where sensitivity appears to be a result of recognition by NK effectors. Because our findings show that transformed and normal cells express the same recognition determinants, in order for NK activity to play an important in vivo role in tumor surveillance, a mechanism must operate to permit NK effectors to find their targets in vivo. In the absence of a special discrimination mechanism, the killing of NK-sensitive transformants that arise autochronously would be less than optimal as a consequence of competition by the normal, NK-resistant, cells.
T cell abnormalities in NZB mice occur independently of autoantibody production.
Authors: Taurog J D , Raveche E S , Smathers P A , Glimcher L H , Huston D P , Hansen C T , Steinberg A D
Published: June 2004

By means of a series of crosses and backcrosses, ZB.CBA/N mice were prepared bearing largely NZB autosomal genes, but having X chromosomes derived only from CBA/N mice. The CBA/N X chromosome carries a gene, xid, that is associated with the lack of a B cell subset necessary for most of the spontaneous autoantibody production by NZB mice. These ZB.CBA/N mice failed to develop autoantibodies to T cells, erythrocytes, or DNA. The availability of mice that were mostly NZB, but which failed to make autoantibodies, especially anti-T cell antibodies, allowed us to study possible T cell regulatory defects in NZB mice in the absence of either antibodies reactive with such T cells or other autoantibodies. We found that such mice had derangements of T cell regulation as did the NZB mice. These observations strongly suggest that the t cell abnormalities of NZB mice are not caused by the B cell hyperactivity of these mice, but rather represent independent defects. Thus, NZB mice appear to have primary defects in both the B cell population and the T cell population. Whether or not these are separate, or derive from a common precursor cell abnormality, remains to be determined.
Human complement in the arachidonic acid transformation pathway in platelets.
Authors: Polley M J , Nachman R L , Weksler B B
Published: June 2004

Arachidonate-mediated release of 14C serotonin and thromboxane B2 (TXB2) is significantly enhanced in the presence of complement. Only purified complement components C5, C6, C7, C8, and C9 are required for this reactivity. No known activating mechanism of the classical or alternative pathway is required, nor is C3. In the absence of exogenously added complement, platelet membrane-bound complement components play an essential role in modulating arachidonate-mediated serotonin release. Incubation of platelet membranes with arachidonate and C5--C9 led to the production of dimers of the membrane attack complex (C5b--9) on the platelet surface. These macromolecular complexes were eluted from the platelet membrane and were identified physicochemically and morphologically. The possibility arises that C3 in association with C5--C9 is required for mobilization of the arachidonic acid from the phospholipid of the platelet membrane. Once the arachidonic acid is mobilized, C3 is no longer required, C5--C9 being sufficient to modulate this pathway leading to enhanced production of TXB2.
A monoclonal antibody that recognizes B cells and B cell precursors in mice.
Authors: Coffman R L , Weissman I L
Published: June 2004

The monoclonal antibody, RA3-2C2, appears to be specific for cells within the B cell lineage. This antibody does not recognize thymocytes, peripheral T cells, or nonlymphoid hematopoietic cells in the spleen or bone marrow. Nor does it recognize the pluripotent hematopoietic stem cells, the spleen colony-forming unit, All sIg+ B cells and most plasma cells are RA3-2C2+. In addition, approximately 20% of nucleated bone marrow cells are RA3-2C2+ but sIg-. This population contains B cell precursors that can give rise to sIg+ cells within 2 d in vitro.
Major histocompatibility complex antigen expression on the epithelium of the developing thymus in normal and nude mice.
Authors: Jenkinson E J , Van Ewijk W , Owen J J
Published: June 2004

The expression and distribution of antigens coded by the K and I regions of the major histocompatibility complex in the developing thymus of normal and nude mice has been investigated using monoclonal antibodies. Both immunohistological studies of intact rudiments and in vitro labeling of cultures derived from microdissected rudiments indicate that, while K region antigens are present on epithelial and mesenchymal elements, I region antigens are only detectable on the epithelium. This view is also substantiated by the selective absence of I region antigens in the abnormal nude thymic rudiment where the defect is considered to be epithelial in nature. The findings are considered in relation to the role of the thymus in providing an environment for the differentiation and selection of developing T cells, and it is proposed that the Ia-expressing epithelial elements play a central role in these functions.
Evolutionary conservation of surface molecules that distinguish T lymphocyte helper/inducer and cytotoxic/suppressor subpopulations in mouse and man
Authors: Ledbetter JA , Evans RL , Lipinski M , Cummingham-Rundles C , Good RA , Herzenberg LA
Published: June 2004

We describe the biochemical properties and cell surface distributions of three human T cell antigens (Leu-1, Leu-2a, and Leu-2b) which we postulate to be the homologues of the Lyt-1, Lyt-2, and Lyt-3 antigens that distinguish functional T cell subsets in the mouse. Leu-l, like Lyt-1, is on all thymocytes and peripheral T cells and is present in greater amounts on the helper/inducer subset than on the cytotoxic/suppressor subset. Both antigens increase in parallel fashion during T cell maturation in the thymus and each antigen is carried on a single 67,000-molecular weight (relative) (M(r)) polypeptide chain. Surprisingly, Leu-1 and Lyt-1 each are also expressed in readily detectable amounts on some B celI Ieukemias but not detectably so on normal B cells.

Leu-2a and Leu-2b are antigens found only on suppressor/cytotoxic cells in the human and are very similar to the murine Lyt-2 and Lyt-3 antigens. In both species, the two antigens are on the same disulfide- linked multimeric molecules. Disulfide-bond reduction in both species yields subunits of similar size and charge. Lyt-3 and Leu-2b are extremely sensitive to trypsin digestion on viable cells whereas Lyt-2 and Leu-2a are much less so.

A different membrane antigen, Leu-3, is an exclusive marker of the helper/inducer subset in man. No mouse homologue for this 55,000-M(r) protein is known.

The maintenance of the homologous molecules on functionally distinct T cell subpopulations in two evolutionarily distant species suggests that the Lyt and Leu antigens perform essential functions for the cells on which they are found.
Antigen-specific T cell clones restricted to unique F(1) major histocompatibility complex determinants. Inhibition of proliferation with a monoclonal anti-Ia antibody
Authors: Sredni B , Matis LA , Lerner EA , Paul WE , Schwartz RH
Published: June 2004

The existence of T cells specific for soluble antigens in association with unique F(1) or recombinant major histocompatibility complex (MHC) gene products was first postulated from studies on the proliferative response of whole T cell populations to the antigen poly(Glu(55)Lys(36)Phe(9))(n) (GLφ). In this paper we use the newly developed technology of T lymphocyte cloning to establish unequivocally the existence of such cells specific for GLφ and to generalize their existence by showing that F(1)- specific cells can be isolated from T cell populations primed to poly(Glu(60)Ala(30)Tyr(10))(n) (GAT) where such clones represent only a minor subpopulation of cells. Gl.4b-primed B10.A(5R) and GAT-primed (B10.A × B10)F(1) lymph node T cells were cloned in soft agar, and the colonies that developed were picked and expanded in liquid culture. The GLφ-specific T cells were then recloned under conditions of high-plating efficiency to ensure that the final colonies originated from single cells. T cells from such rigorously cloned populations responded to stimulation with GILφ but only in the presence of nonimmune, irradiated spleen cells bearing (B10.A × B10)F(1) or the syngeneic B 10.A(5R) recombinant MHC haplotype. Spleen cells from either the B10 or B 10.A parental strains failed to support a proliferative response, even when added together. (B10 × B10.D2)F(1) and (B10 × B10.RIII)F(1) spleen cells also supported a proliferative response but (B10 × B10.Q)F(1) and (B10 X B10.S)F(1) spleen cells did not. These results suggested that the T cell clones were specific for GL[phi} in association with the β(AE)(b)-α(E) (k,d,r,) Ia molecule and that recognition required both gene products to be expressed in the same antigen-presenting cells. Support for this interpretation was obtained from inhibition experiments using the monoclonal antibody Y-17 specific for a determinant on the β(AE)(b)-αE Ia molecule. Y-17 completely inhibited the proliferative response of a GLφ-specific clone but had no effect on the response of either a PPD-specific or GAT-specific clone, both of which required the β(A)-α(A) Ia molecule as their restriction element. No evidence could be found for the involvement of suppressor T cells in this inhibition. We therefore conclude that the phenomenon of F(1)-restricted recognition by proliferating T cells results from the presence of antigen- specific clones that must recognize unique F(1) or recombinant Ia molecules on the surface of antigen-presenting cells in addition to antigen in order to be stimulated.
Antiphosphocholine antibodies found in normal mouse serum are protective against intravenous infection with type 3 streptococcus pneumoniae.
Authors: Briles D E , Nahm M , Schroer K , Davie J , Baker P , Kearney J , Barletta R
Published: June 2004

The antiphosphocholine (PC) antibody in normal mouse sera (NMS) provides protection against intravenous infection with encapsulated strain WU2 of type 3 Streptococcus pneumoniae. Mice unable to make anti-PC antibody, as a result of suppression with anti-T-15 idiotype or inheritance of the xid gene of CAB/N mice, are highly susceptible to infection with strain WU2. Mice inheriting the xid gene can be protected with NMS from immunologically normal mice or with IgM hybridoma anti-PC antibody. The protective effect of NMS can be removed with PC-containing immunoabsorbents.
Specific selection of antigen-reactive lymphocytes into antigenically stimulated lymph nodes in sheep.
Authors: Hopkins J , McConnell I , Lachmann P J
Published: June 2004

Sheep were primed to a variety of antigens and the efferent lymphatic from a popliteal lymph node was cannulated. The cannulated node was challenged repeatedly with PPD and all the lymph and cells removed from the animal. During this time the PBL were monitored for reactivity to all antigens (purified protein derivative of tuberculin [PPD], johnin, and keyhole limpet hemocyanin [KLH]) by the vitro transformation assay. The response of these cells to PPD was found to be gradually eliminated after repeated challenge of the cannulated node with that antigen. The response to the other antigens was unimpaired. No depletion of this response to PPD occurred in cannulated sheep when the antigen was given into a noncannulated node. In vivo delayed-type hypersensitivity skin test and helper T cell assays confirmed that there is a specific selection of antigen-reactive cells from the recirculating lymphocyte pool into antigen-stimulated lymph nodes.
Adjuvant polyarthritis. V. Induction by N-acetylmuramyl-L-alanyl-D-isoglutamine, the smallest peptide subunit of bacterial peptidoglycan.
Authors: Chang Y H , Pearson C M , Chedid L
Published: June 2004

N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP), an apparently nonimmunogenic bacterial peptidoglycan-derived small peptide, was found to induce a polyarthritis the rat similar to that induced by Freund's complete adjuvant when injected in the form of an oil emulsion. An oil emulsion of its isomer, N-acetylmuramyl-L-alanyl-L-isoglutamine, which unlike MDP has no immunostimulatory activity, failed to induce the disease.
A clonal analysis of the IgE response and its implications with regard to isotope commitment.
Authors: Teale J M , Liu F T , Katz D H
Published: June 2004

In a clonal analysis of the IgE response, it was found that a small proportion of primary or nonimmune B cells in spleen and mesenteric lymph nodes can be stimulated by antigen to produce IgE-secreting clones. In addition, there appears to be no substantial difference in the frequency of such cells between the classical low and high IgE responder strains. An analysis of immune, or memory, B cells revealed substantial increases in the frequency of B cells secreting IgE as compared with primary B cells, although the actual proportion of B cells secreting IgE remained relatively low. When the IgE-secreting clones derived from either primary or secondary B cells were reanalyzed for the presence of other isotypes, it was found that all clones secreting IgE were secreting at least one other isotype, with the majority secreting two or three other isotypes in addition to IgE. This demonstrates that there is no distinct subpopulation of B cells committed to IgE expression per se.
Effector T lymphocytes in lymphocytic choriomeningitis virus-infected mice. Cytolytic activity of Lyt-23 spleen cells in vitro does not correlate with elimination of infectious virus from spleens.
Authors: Varho M , Lehmann Grube F , Simon M M
Published: June 2004

The T lymphocytes from mice recovering from infection with lymphocytic choriomeningitis virus were selected for subclasses by treatment with anti-Lyt antisera and complement. Lyt-23 cells and mixtures of lyt-1 and Lyt-23 cells caused up to one-half the destruction of cultivated target cells as compared with untreated T lymphocytes; Lyt-1 cells alone were not cytotoxic. Selected and unselected spleen T cells were also inoculated intravenously into previously infected mice. Whereas unselected cells reduced infectious virus in the spleens of the recipients approximately 100-fold, only marginal effects, which were not preferentially associated with one particular subclass, were seen with selected LYT-23 or Lyt-1 lymphocytes or a mixture of both. Apparently the Lyt-23 cells, shown to by cytolytic for infected cells in vitro, did not cause elimination of a measurable quantity of the virus from mice.
Accumulation of protoporphyrin IX from delta-aminolevulinic acid in bovine skin fibroblasts with hereditary erythropoietic protoporphyria. A gene-dosage effect.
Authors: Sassa S , Schwartz S , Ruth G
Published: June 2004

Bovine skin fibroblasts accumulated protoporphyrin IX when incubated in culture with the porphyrin-heme precursor, delta-aminolevulinic acid (ALA). Fibroblasts from cattle homozygous for erythropoietic protoporphyria (EPP) and with the clinical symptoms of the disease accumulated approximately sixfold greater amounts of protoporphyrin IX than cells from normal control animals. Cells from obligatory heterozygous animals, which are clinically normal, accumulated an intermediate level of protoporphyrin IX. When these cells were incubated with ALA and CaMg EDTA, all types of cells accumulated approximately the same amount of protoporphyrin IX (approximately 500 nmol/mg protein), suggesting that ferrochelatase activity was equally low after inhibition by treatment with CaMg EDTA in all cells. Thus the ratio of protoporphyrin IX accumulation from ALA in cultures treated with CaMg EDTA compared with controls treated with ALA alone was greatest in normal cells, least in EPP cells, and intermediate in the heterozygote cells. These findings suggest that the amount of protoporphyrin IX accumulation from ALA reflects the extent of deficiency of ferrochelatase and is proportional to the dosage of abnormal EPP gene in cultured fibroblasts. Similarly, stimulation of porphyrin accumulation by CaMg EDTA reflects diminished ferrochelatase activity in these cells. Thus, the results of this study demonstrate the usefulness of estimating protoporphyrin IX formation from ALA for the detection of an EPP gene defect in cultured bovine skin fibroblasts.
Genetic studies in NZB mice. V. Recombinant inbred lines demonstrate that separate genes control autoimmune phenotype.
Authors: Raveche E S , Novotny E A , Hansen C T , Tjio J H , Steinberg A D
Published: June 2004

The genetic basis for autoimmunity in NZB mice has been investigated through analysis of recombinant inbred lines produced by mating NZB mice with two different non-autoimmune strains. Several genes (at least six) were found to be necessary for the production of eight traits characteristic of the NZB mice that were studied. No fundamental genetic defect (an "autoimmunity gene") was identified that could give rise to the various autoimmune traits studied. This study strongly suggests that NZB disease results from the actions of several separate genes that together result in the characteristic manifestations of autoimmunity.