bluuebunny/crossref_metadata_2025 huggingface dataset:
Spleen cells from adult mice given total lymphoid irradiation or from newborn mice have similar regulatory effects in the mixed leukocyte reaction. I. Generation of antigen-specific suppressor cells in the mixed leukocyte reaction after the addition of spleen cells from adult mice given total lymphoid irradiation.
Authors: Okada S , Strober S
Published: June 2004

We added spleen cells from adult BALB/c mice treated with total lymphoid irradiation (TLI) to the mixed leukocyte reaction (MLR) using a variety of responder and stimulator cells. The spleen cells nonspecifically suppressed the uptake of [3H]-thymidine and the generation of cytolytic cells regardless of the responder-stimulator combination used. We also examined the effect of the spleen cells on the generation of antigen-nonspecific and antigen-specific suppressor cells in the MLR. The experimental results suggest that the spleen cells from TLI-treated mice inhibit the generation of nonspecific suppressor cells, but do not inhibit the generation of antigen-specific suppressor cells. Thus, alloantigenic stimulation of normal responder cells in vitro in the presence of spleen cells from TLI-treated mice generates large numbers of antigen-specific suppressor cells, but few cytolytic cells or nonspecific suppressor cells. Similar nonspecific inhibition of the MLR was observed with neonatal spleen cells. This in vitro system provides a regulatory model for the induction and maintenance of tolerance in vivo, in which adult mice given TLI or neonatal mice accept allogeneic bone marrow transplants without graft-vs.-host disease.
Biochemical characterization of a second family of human Ia molecules, HLA-DS, equivalent to murine I-A subregion molecules.
Authors: Goyert S M , Shively J E , Silver J
Published: June 2004

In mice, two families of structurally distinct Ia molecules, one designated I-A and the other I-E, have been identified and characterized. The HLA-DR molecules represent one family of human Ia molecules equivalent to the murine I-E molecules on the basis of amino acid sequence homology. We describe the isolation and biochemical characterization of a second family of human Ia molecules, designated HLA-DS for second D-region locus, equivalent to the murine I-A molecules. The human HLA-DS molecules consist of two polypeptide chains, DS alpha (37,000 mol wt) and DS beta (29,000 mol wt), with 73% amino acid sequence identity to the murine I-A molecules. Furthermore, the HLA-DS molecules are closely linked genetically to HLA-DR molecules, a situation analogous to that observed in mice. The similarity in molecular weights of the DR and DS molecules might explain why others have failed to identify the latter in man.
Primary in vitro cytotoxic T cell response to non-major histocompatibility complex alloantigens in normal mice.
Authors: Macphail S , Yron I , Stutman O
Published: June 2004

We have shown for the first time that it is possible to consistently generate a primary in vitro cytotoxic T cell (Tc) response to non-major histocompatibility complex alloantigens using responder cells from a normal mouse strain. This was achieved by carrying out, in the generating phase, a limiting dilution procedure in which it appears that suppressor cells that inhibit Tc activation or expansion are too dilute to manifest their effect. Moreover, the response was observed in mouse serum-(MS) as well as fetal calf serum- (FCS) supplemented media, an important finding in the light of the anomalous nonspecific effects induced by FCS. The cytotoxic response produced in MS-supplemented media was shown to be highly specific in both the generating and effector phases, whereas the responses in FCS had a strong nonspecific component.
Thymic hormone-containing cells. Characterization and localization of serum thymic factor in young mouse thymus studied by monoclonal antibodies.
Authors: Savino W , Dardenne M , Papiernik M , Bach J F
Published: June 2004

The characterization and distribution of cells containing the serum thymic factor (FTS) in the thymus of young mice was studied by immunofluorescence using monoclonal anti-FTS antibodies. FTS+ cells were distributed throughout the thymic parenchyma but were more frequent in the medullary region than in the cortex. FTS-containing cells presented a stellate or globular aspect, and some of them exhibited fluorescent cytoplasmic granules. The epithelial nature of FTS+ cells was confirmed by double-labeling experiments using an anti-keratin antiserum (as an epithelial cell marker). Nevertheless, only a minority of keratin-positive epithelial reticular cells contained FTS. All controls, including the incubation of sections from nonthymic tissues with the anti-FTS antibodies, were negative. Taken together, these results confirm the exclusive localization of FTS-containing cells within the mouse thymus.
Selective abrogation of antigen-specific human B cell responses by antigen-ricin conjugates.
Authors: Volkman D J , Ahmad A , Fauci A S , Neville D M
Published: June 2004

The feasibility of selectively eliminating human antigen-specific B cell responses by treating cells in vitro with antigen covalently linked to a cell toxin was examined. Tetanus toxoid (TT) was conjugated to the toxin ricin via a thioether linkage. Peripheral blood mononuclear cells from recently immunized subjects were preincubated for 2 h with TT-ricin in the presence of lactose. Antigen was then removed, and the cells from recently immunized subjects were preincubated for 2 h with TT-ricin in the presence of lactose. Antigen was then removed, and the cells were stimulated with pokeweed mitogen to induce antibody production. TT-specific antibody production was completely abrogated by preincubation with TT-ricin but not by TT alone or a mixture of TT and ricin. In contrast, polyclonal immunoglobulin production was not diminished by TT-ricin. This selective abrogation was also seen when B cells alone were preincubated with TT-ricin and a source of T cell help was later provided. T cell blastogenic responses to TT remained intact after TT-ricin exposure. Thus, antigen-toxin conjugates are capable of selectively eliminating specific antibody-producing B cell clones, while leaving intact the remainder of the B cell repertoire.
Production of autoreactive I region-restricted T cell hybridomas.
Authors: Glimcher L H , Shevach E M
Published: June 2004

We produced autoreactive T cell hybridomas that can be induced to secrete interleukin 2 by co-culture with either syngeneic splenic stimulator cells or syngeneic Ia-positive B cell-B lymphoma hybridomas. These autoreactive hybridomas arose from the fusion of pork insulin-primed lymph node T cells with the AKR thymoma BW 5147 and occurred at a higher frequency than the expected insulin-specific hybridomas. Mapping studies using recombinant strains and blocking studies using monoclonal anti-Ia antibodies localized the stimulatory determinant to the I-Ad subregion of the major histocompatibility complex. These T cell hybridomas did not appear to be directed at any foreign antigen present in the culture system because activation occurred in serum-free, insulin-free medium (Iscove's medium). Such hybridomas should prove to be a potent tool in studying the biologic significance and function of the autoreactive response.
A cloned cell line mediating natural killer cell function inhibits immunoglobulin secretion.
Authors: Nabel G , Allard W J , Cantor H
Published: June 2004

We previously described a cloned cell line that combines information for a unique display of cell surface antigens and specialized function similar to activated natural killer (NK) cells. In addition to conventional cellular targets such as the YAC-1 and MBL-2 lymphomas, this cloned line also lysed lipopolysaccharide-activated B lymphocytes. To determine whether some NK cells can inhibit B cell function, we tested the ability of NK-like clones to suppress Ig secretion in vitro and in vivo. These cloned cells suppressed Ig secretion when they constituted as few as 0.2% of the total cell population and inhibition did not require identity at the H-2 locus. We suggest that some NK cells might recognize non-major histocompatibility complex gene products on activated B lymphocytes and lyse these cells, and this might represent a fundamental cell-cell interaction that regulates antibody secretion by activated B cells.
Inducible expression of insulin receptors on T lymphocyte clones.
Authors: Braciale V L , Gavin J R , Braciale T J
Published: June 2004

This study demonstrates that the insulin receptors are expressed on the surface of some T cell clones after specific antigenic stimulation. The insulin receptors on these lymphocytes are physicochemically similar to insulin receptors present on cells which express the receptors constitutively (adipocytes, hepatocytes, etc.). The kinetics of expression of insulin receptors on cloned, noncytotoxic T cells after specific antigenic stimulation closely parallels that of [3H]thymidine incorporation in such cultures.
Multiple human beta interferon genes.
Authors: Sagar A D , Sehgal P B , Slate D L , Ruddle F H
Published: June 2004

Analysis of human beta interferon (IFN) mRNA preparations obtained from poly(I) . poly (C)-induced human diploid fibroblasts (FS-4) and from several similarly induced human-mouse somatic cell hybrids by electrophoresis through agarose-CH3HgOH tube gels led to the detection of at least five translationally active human IFN-beta mRNA species. The results obtained are consistent with the existence of IFN-beta genes on different human chromosomes. Marked cell-dependent variability in the expression of these IFN mRNA species was observed.
Effect of cationized antibodies in performed immune complexes on deposition and persistence in renal glomeruli.
Authors: Gauthier V J , Mannik M , Striker G E
Published: June 2004

To study the interaction of positively charged antibodies in immune complexes with the fixed negative charge on the glomerular capillary wall, chemical cationization of antibody was accomplished with the maintenance of antigen-binding activity. These cationized antibodies bound rapidly to glomeruli but did not persist. Large-latticed immune complexes formed with these cationic antibodies showed rapid deposition and persistence in renal glomeruli, even when administered in small doses. Electron-dense deposits were present at the anionic sites in the glomerular basement membrane at 1 min and 1 h, with extensive subendothelial deposits present from 12 to 72 h. By 14 d, the deposits were seen in the subepithelial region and the glomerular mesangium. The administration of small-latticed immune complexes prepared with cationized antibody revealed initial deposition without persistence in glomeruli in a manner similar to cationized antibodies alone. Thus, the positive charges on antibodies in immune complexes contribute to the deposition and persistence of the complexes in glomeruli, particularly in the subendothelial area.
Genetic control of the immune response to myoglobins. Both low and high responder T cells tolerant to the other major histocompatibility complex help high but not low responder B cells
Authors: Kohno Y , Berzofsky JA
Published: June 2004

We sought to examine the role of immune response (Ir) genes in helper T cells. To eliminate allogeneic effects, we used neonatally tolerized mice. The results bear not only on the mechanism of Ir genes, but also on the development of the T cell repertoire. B 10.BR (H-2(k)) or C57BL/10 (H-2(b)) mice, which were low responders to myoglobin (Mb), were neonatally tolerized to high responder H-2(d) alloantigens, and B10.D2 mice, which were high responders to Mb, were neonatally tolerized to low responder H-2(k) or H-2(b) alloantigens. Spleen cells from these tolerized mice did not show any reactivity in mixed-lymphocyte reaction or cell-mediated lympholysis against alloantigens used in tolerization. Mb-immune F(1) B cells were helped comparably by Mb-immune tolerized low or high responder T cells. Thus, low responder T cells functioned equivalently to high responder T cells. The failure of nonimmune T cells from tolerized low responder mice to help F(1) B cells and antigen-presenting cells (APC) indicated that collaboration between B10.BR or C57BL/10 T cells and F(1) B cells was not caused by a positive allogeneic effect. Spleen cells from tolerized mice were contaminated with 2-4 percent chimeric F(1) cells, as judged by fluorescence-activated cell sorter analysis, and no F(1) alloantigens were detectable in the thymus. However, removal of chimeric F(1) T cells from the tolerized cell population by treatment with anti-H-2 and complement did not change the helper activity of tolerized low responder T cells. These data indicated that helper activity in the T cell population from low responder mice was not due to F(1) cells. Also, the level of contamination was not sufficient to quantitatively account for the help. In examining the genetic restriction of these tolerized T cells, we found that T cells from tolerized low responder B10.BR or C57BL/10 mice helped F(1) or high responder B10.D2 B cells and APC but not syngeneic B10.BR or C57BL/10 B cells and APC, which were immunized with Mb-coupled fowl gamma globulin instead of Mb to prime low responder B cells with Mb. On the other hand, high responder B 10.D2 tolerized T cells helped syngeneic B 10.D2 B cells but not allogeneic low responder B10.BR B cells.

These data indicated that clones of helper T cells specific for Mb exist in low responder mice, and these are not phenotypically different from those in high responder mice, in that both help high responder and F(1) but not low responder B cells and APC. These data are discussed in terms of the mechanism for Ir gene control, and the mechanism of T cell repertoire development- whether intra- or extrathymically-in neonatally tolerized mice.
H-2-controlled suppression of T cell response to lactate dehydrogenase B. Characterization of the lactate dehydrogenase B suppressor pathway.
Authors: Baxevanis C N , Ishii N , Nagy Z A , Klein J
Published: June 2004

We characterized the cell types involved in the H-2-controlled suppression of T cell response to lactate dehydrogenase B (LDHB). The suppressor effector (Tse) was found to be an Lyt-1+2+, J+ cell that recognizes antigen together with Ek molecules of antigen-presenting cells (APC). To become functional, the Tse cell requires a second signal from a nonspecific, Lyt-1+2-, J+ suppressor-inducer (Tsi) cell. The Tsi-Tse interaction is not subject to any genetic restriction. The target cell of suppression is an Lyt-1+2-, J- (most likely T helper [Th]) cell that recognizes LDHB in the context of A molecules on APC. The suppression is manifested in inhibition of the antigen-specific, A-restricted proliferation of Th cells. The interaction between Tse and Th is restricted by the A region of the H-2 complex. Because this restriction is determined by the receptor of Th cells, the mechanism of Th-Tse interaction most likely involves a concomitant recognition of LDHB and A region-controlled molecules by Th cells on the surface of Tse cells.
Cooperative interaction of factor B and other complement components with mononuclear cells in the antibody-independent lysis of xenogeneic erythrocytes.
Authors: Hall R E , Blaese R M , Davis A E , Decker J M , Tack B F , Colten H R , Muchmore A V
Published: June 2004

Synergistic cytotoxicity is a term used to describe a cytotoxic system in which xenogeneic erythrocyte target cells are lysed in the presence of nonimmune human mononuclear effector cells and antibody-depleted normal human serum. Neither the mononuclear cells nor the serum alone are cytolytic to the target erythrocytes. Previous studies have shown that the serum activity is not immunoglobulin and is heat-labile, suggesting a similarity to serum complement. In this report, sera deficient in various complement components as well as highly purified single complement components were tested with whole mononuclear cell populations and purified monocytes and lymphocytes to further characterize this cytotoxicity system. Whole mononuclear cell populations failed to mediate target cell lysis in sera deficient in C5 or factor B. However, C3-deficient serum, even in the presence of anti-C3 antibody, supported synergistic cytotoxicity normally. Purified lymphocytes were also normally cytotoxic in C3-deficient serum but failed to lyse targets in sera deficient in C5, C7, C8, or depleted of factor B. Purified monocytes failed to lyse the target cells only in factor B-depleted serum and could lyse the target cells in serum-free medium when purified factor B alone was added. Monocyte-mediated cytotoxicity induced by factor B was inhibited 73-100% by adding lymphocytes back to the purified monocytes. Thus, both lymphocytes and monocytes can serve as effector cells in this form of cytotoxicity but require cooperative interaction with different sets of complement components. In addition, lymphocytes can modulate the monocyte-mediated form of target cell lysis associated with factor B.
Generation of cytolytic T lymphocytes in thymectomized, irradiated, and bone marrow-reconstituted mice.
Authors: Duprez V , Hamilton B , Burakoff S J
Published: June 2004

A model system has been developed to study extrathymic T cell differentiation. Mice have been thymectomized, lethally irradiated, and reconstituted with bone marrow cells depleted of Thy-1-positive cells. After 8 wk, the spleen cells of these 5athymic, bone marrow-reconstituted chimeras contain Thy-1-positive pre-cytolytic T lymphocytes (CTL) that are able to respond to antigen only when exogenous interleukin 2 is added to culture.. The phenotype of these pre-CTL is similar to that of thymocytes, suggesting that they may be an immature T cell. Initial evaluation of the CTL repertoire of these athymic mice demonstrates that the CTL generated to trinitrophenyl-modified syngeneic cells are H-2 restricted and that the CTL generated to alloantigens have many of the cross-reactivities observed in normal but not in nude mice. The discrepancies observed in the CTL repertoire between these thymectomized chimeras and nude mice are discussed.
Lymphocyte abnormality associated with HLA-B8 in healthy young adults.
Authors: McCombs C C , Michalski J P
Published: June 2004

We have reported that abnormal lymphocyte function in Sjogren's syndrome occurs almost exclusively in patients with HLA-B8. We now report that most clinically normal individuals with this antigen have a similar impairment of cellular immunity. This finding suggests that the lymphocyte abnormality in Sjogren's syndrome is not secondary to the disease process or medication and might have primary etiological significance. The lymphocyte abnormality is expressed as a decreased proliferative response to suboptimally stimulating concentrations of phytohemagglutinin (PHA) and concanavalin A (Con A). In contrast, the response to optimally stimulating concentrations of PHA and Con A is unaffected. The imparied mitogen responsiveness appears to be intrinsic to the T lymphocytes, as it can be demonstrated in purified T cell preparations.
Anti-phosphorylcholine antibodies of the T15 idiotype are optimally protective against Streptococcus pneumoniae.
Authors: Briles D E , Forman C , Hudak S , Claflin J L
Published: June 2004

In the mouse, most anti-PC antibody is found in one of the three murine anti-PC idiotype families: T15, M603, or M511. The antibodies within each of these idiotypic families have characteristic fine specificities for phosphorylcholine (PC)-analogues. In this paper we compare the ability of hybridoma IgM anti-PC antibodies of the three idiotype families to protect mice from fatal infection with S. pneumoniae. Antibody bearing the T15 idiotype was approximately 8 times as effective as antibody with the M603 idiotype and approximately 30 times as protective as antibody with the M511 idiotype. Reports by others have shown that the heavy chains of virtually all mouse anti-PC antibodies are produced by translocation of a single variable region gene and that the direct translation of this gene (in the absence of somatic mutations) results in heavy chains characteristic of the T15 idiotype. Thus, our findings suggest that the T15 germ line heavy chain variable region gene may have been selected through evolution to code for antibody binding PC-containing pathogens such as S. pneumoniae. Our observations may also explain the existence of regulatory mechanisms that result in maintenance of T15 idiotype expression in murine anti-PC immune responses.
The acute-phase response in (NZB X NZW)F1 and MRL/l MICE.
Authors: Rordorf C , Schnebli H P , Baltz M L , Tennent G A , Pepys M B
Published: June 2004

The acute-phase plasma protein response to disease activity in murine models of autoimmune lupus-like disease was investigated by measurement of the concentration of serum amyloid P component (SAP) in NZB X W and MRL/l mice. The levels of SAP, which is a major acute-phase protein in mice, did not rise at all in response to progression of disease in NZB X W mice between the ages of 1 and 9 mo. This resembles the behavior of acute-phase proteins such as C-reactive protein and serum amyloid A protein in human systemic lupus erythematosus, and just as in human lupus, where the occurrence of intercurrent microbial infection can stimulate an acute-phase response, so injection of bacterial lipopolysaccharide or casein into the NZB X W mice stimulated "normal" acute-phase SAP production. In marked contrast, MRL/l mice developed greatly increased levels of SAP, which correlated closely with progression of their pathology as they aged. The disease profile of the MRL/l strain includes rheumatoid factors and spontaneous polyarthritis and their SAP response resembles the behavior of acute phase proteins in human rheumatoid arthritis. Different patterns of acute-phase response in different autoimmune disorders may thus be a reflection of the genetic predisposition to particular diseases and/or contribute to their pathogenesis. The existence of animal counterparts for the various clinical patterns of human acute-phase protein production will assist in experimental investigation of the underlying mechanisms and of the biological role of the acute-phase response.
Suppression of macrophage oxidative metabolism by products of malignant and nonmalignant cells.
Authors: Szuro-Sudol A , Nathan C F
Published: June 2004

Each of 11 tumors tested produced a factor that markedly suppressed the ability of macrophages to release H2O2 or O.2- in response to phorbol myristate acetate or zymosan. Four of seven normal cell types produced a similar activity, which was 3.5-7 times lower in titer than that in tumor cell-conditioned medium (TCM), and which was much more rapidly reversible in its effects. TCM caused 50% inhibition of H2O2 release when it was present in the medium for 48 h at a concentration of 13%, or when 100% TCM was present in the medium for 18 h. The H2O2-releasing capacity of macrophages incubated in TCM only returned to control levels by 6 d after its removal. TCM prevented augmentation of H2O2-releasing capacity by lymphokines. The titer of suppressive activity in TCM depended on both the concentration of tumor cells and the duration of their incubation. TCM did not augment the activity of catalase, myeloperoxidase, glutathione peroxidase, or glutathione reductase or the content of glutathione within macrophages, suggesting that decreased synthesis rather than increased catabolism was responsible for reduced secretion of H2O2. Suppression of the release of H2O2 or O.2- by TCM appeared to be a relatively specific effect, in that TCM increased macrophage spreading and adherence to glass while exerting little influence on rates of phagocytosis, synthesis of protein, or secretion of lysozyme, plasminogen activator, or arachidonic acid and its metabolites. Thus, tumor cells and some normal cells can secrete a factor that selectively deactivates macrophage oxidative metabolism.
Anti-immunoglobulin antibodies. III. Properties of sequential anti-idiotypic antibodies to heterologous anti-gamma globulins. Detection of reactivity of anti-idiotype antibodies with epitopes of Fc fragments (homobodies) and with epitopes and idiotopes (epibodies).
Authors: Bona C A , Finley S , Waters S , Kunkel H G
Published: June 2004

Murine anti-V region antibodies against a human monoclonal protein Gl with anti-gamma-globulin activity and bearing the Wa cross-reactive idiotype were prepared in several strains of mice. Antibodies were obtained that were specific for the Gl idiotype, the Wa cross-reactive idiotype, and for various framework antigenic determinants that were distinguished by a variety of procedures. Synthesis of such antibodies were found to be independent of MHC and Igh gene complexes. These anti-V region antibodies, produced by a majority of mouse strains investigated, also share a cross-reactive idiotype recognized by BALB/c anti-anti-V region Gl antibodies. A fraction of BALB/c anti-anti-V region Gl antibodies displayed human Fc gamma binding activity and, therefore, can be considered homobodies, as described in other systems. Two of the anti-idiotype antibodies obtained in this system exhibited a peculiar property: they interacted not only with their own antigen (IgM Gl), but also with the Fc fragment with which IgM Gl reacts. Thus, A/J anti-V region Gl antibodies bind to the human Fc gamma fragment in addition to IgM Gl. Similarly, a monoclonal CB6 F1 anti-anti-V region Gl antibody interacted with the V region of IgM Gl as well as with the syngeneic anti-V region antibodies. We called these anti-idiotypic antibodies epibodies because they interact with epitopes of the primary antigen. These homobodies and epibodies, obtained by immunization across heterologous barriers, represent new examples of recognition of the internal image of the antigen within the immune system.
Variable major proteins of Borrellia hermsii.
Authors: Barbour A G , Tessier S L , Stoenner H G
Published: June 2004

Borrelia hermsii, a relapsing fever agent, manifests antigenic variation in vivo and in vitro. We studied three mouse-passaged serotypes of strain HS1 (7, 14, and 21) and a HS1 derivative obtained after multiple in vitro passages (C serotype). All four serotypes had two major proteins in whole cell lysates fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. One major protein species (pII) had the same apparent subunit molecular weight (or approximately 3.9 X 10(4) in all the serotypes. In contrast, the other abundant protein in lysates, pI, had a different apparent molecular weight in each serotype. In one gel the molecular weights of pIc, pI7, pI14, and pI21 were 1.9, 4.2, 4.1, and 4.0 X 10(4), respectively. Serotype-specific mouse antisera bound to both hemologous and heterologous pIIs, to homologous pI, but not to heterologous pI in Western blots. Hybridomas were raised from spleens of mice infected with B. hermsii. Monoclonal antibodies were identified by immunofluorescence assays using whole organisms. Monoclonal antibodies specific for serotype 7 (H1826) or for serotype 21 (H3326) bound only to pI7 or pI21, respectively, in Western blots. The surface location of the pI was suggested not only by the immunofluorescence studies but also by the labeling of pI7 and pI21 when whole cells of serotypes 7 and 21 were incubated with 125I in the presence of Iodogen. Under the same circumstances, pII was relatively poorly labeled. These studies have identified the variable pI proteins of B. hermsii as serotype-specific antigens. A change from one pI to another may be the basis of antigenic variation of Borrelia species during relapsing fever.
Regulation of azophenylarsonate-specific repertoire expression. 1. Frequency of cross-reactive idiotype-positive B cells in A/J and BALB/c mice.
Authors: Sigal N H
Published: June 2004

A large proportion of p-azophenylarsonate (ARS)-specific antibodies from A/J mice share a cross-reactive idiotype (CRIA) that comprises a family of closely related but nonidentical clonotypes. I determined that only 2.6 % (7 out of 267) A/J ARS-specific monoclonal antibodies generated in the splenic focus system possess the predominant CRIA. Because ARS-specific B cells are present at a frequency of 1/68,000 B cells, the frequency of the entire idiotype family is 1 per 2.8 X 10(6) splenic B cells. Thus, there is a striking discrepancy between the representation of this idiotype at the clonal precursor cell level and the serum antibody response. In addition, BALB/c mice have the potential to generate CRIA-positive precursor cells within their nonimmune repertoire. When A/J mice are immunized with ARS-protein conjugates, the serum antibody response and precursor cell population are both dominated by CRIA. The frequency of CRIA-positive B cells increases over 100-fold after immunization, whereas CRIA-negative precursor cells may initially decrease, followed by a later rise in frequency. Finally, although ARS-specific precursor cells are present in high frequency at birth, CRIA-positive monoclonal anti-ARS antibodies are not observed during the early neonatal period. These data provide evidence to suggest that complex regulatory networks influence precursor cell and serum antibody expression.
Genetic control of immune response to myoglobin. Ir gene function in genetic restriction between T and B lymphocytes.
Authors: Kohno Y , Berzofsky J A
Published: June 2004

We studied the genetic restrictions on the interaction between T cells, B cells, and antigen-presenting cells (APC) involved in the H-2-linked Ir gene control of the in vitro secondary antibody response to sperm whale myoglobin (Mb) in mice. The B cells in this study were specific for Mb itself, rather than for a hapten unrelated to the Ir gene control, as in many previous studies. Low responder mice immunized in vivo with Mb bound to an immunogenic carrier, fowl gamma globulin (F gamma G), produced B cells competent to secrete anti-Mb antibodies in vitro if they received F gamma G-specific T cell help. However, (high-responder X low responder) F1 T cells from Mb-immune mice did not help these primed low responder (H-2k or H-2b) B cells in vitro, even in the presence of various numbers of F1 APC that were demonstrated to be component to reconstitute the response of spleen cells depleted by APC. Similar results were obtained with B6 leads to B6D2F1 radiation bone marrow chimeras. Genotypic low responder (H-2b) T cells from these mice helped Mb-primed B6D2F1B cells plus APC, but did not help syngeneic chimeric H-2b B cells, even in the presence of F1 APC. In contrast, we could not detect any Ir restriction on APC function during these in vitro secondary responses. Moreover, in the preceding paper, we found that low responder mice neonatally tolerized to higher responder H-2 had competent Mb-specific helper T cells capable of helping high responder but not low responder B cells and APC. Therefore, although function Mb-specific T cells and B cells both exist in low responder mice, the Ir gene defect is a manifestation of the failure of syngeneic collaboration between these two cell types. This genetic restriction on the interaction between T cells and B cells is consistent with the additional new finding that Lyb-5-negative B cells are a major participant in ths vitro secondary response because it is this Lyb-5-negative subpopulation of B cells that have recently been shown to require genetically restricted help. The Ir gene defect behaves operationally as a failure of low responder B cells to receive help from any source of Mb-specific T cells either high responder, low responder, or F1. The possible additional role of T cell-APC interactions, either during primary immunization in vivo or in the secondary culture is discussed.
In vitro regulation of IgA subclass synthesis. I. Discordance between plasma cell production and antibody secretion.
Authors: Conley M E , Koopman W J
Published: June 2004

To investigate the in vitro regulation of IgA subclass synthesis, peripheral blood lymphocytes from healthy adults were cultured with the polyclonal B cell activator, pokeweed mitogen. Although 50% of the IgA plasma cells from a 7-d culture were positive for cytoplasmic IgA1 and 50% were positive for IgA2, less than 10% of the IgA released into the culture supernatant was IgA2. This discrepancy could not be explained by failure of the assay to detect in vitro synthesized IgA2, selective loss or destruction of IgA2 in culture media, delayed release of IgA2, or failure of IgA2 plasma cells to produce J chain. The results suggest that additional signals may be required for the differentiation of plasma cells into immunoglobulin-secreting cells.
Antigen-specific suppression in genetic responder mice to L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT). Characterization of conventional and hybridoma-derived factors produced by suppressor T cells from mice injected as neonates with syngeneic GAT macrophages.
Authors: Sorensen C M , Pierce C W
Published: June 2004

Spleen cells from C57BL/10 mice injected with syngeneic B10 L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT)-pulsed macrophages (GAT-M phi) within 18 h of birth were unable to respond to soluble GAT, GAT-methylated bovine serum albumin, or B10 GAT-M phi as adults. Spleen cells from these neonatally treated mice responded at control levels to GAT presented in allogeneic M phi and to sheep erythrocytes. Partially purified T cells from these neonatally treated mice suppressed responses by syngeneic virgin, but not primed, spleen cells in an antigen-specific manner and acted during the early phases of the response. These responder GAT-specific suppressor T cells (GAT-TSR) were sensitive to anti-Thy-1 + C and 500-rad irradiation and have the phenotype Ly-1-2+, I-J+; GAT-TSR cells can only suppress responses by spleen cells syngeneic with the GAT-TSR cells at the I-J subregion of H-2. Restimulation of these Ts cells with syngeneic GAT-M phi induces an antigen-specific suppressor factor within the supernatant fluid. The factor, GAT-TsFR, is a glycoprotein with a molecular weight between 48,000 and 63,000, as determined by gel filtration chromatography using isotonic buffers; it bears serologically detectable determinants encoded by the I-J subregion of the H-2 complex, has an antigen-binding site for GAT and L-glutamic acid50-L-tyrosine50, and shares idiotypic determinants with anti-GAT antibodies. The presence of GAT-TsFR in the first 36 h of in vitro culture is required for significant suppression. Furthermore, only responses by spleen cell syngeneic with the cells producing GAT-TsFR at the I-J subregion are suppressed. The fusion of GAT-TsFR-producing cells with BW5147 resulted in generation of two hybridomas with properties and characteristics identical to those of the conventional GAT-TsFR with one exception: conventional and hybridoma 372.D6.5 GAT-TsFR only suppress responses by spleen cells of the I-Jb haplotype, whereas suppression mediated by the second hybridoma GAT-TsFR (372.B3.5) is genetically unrestricted. These hybridoma GAT-TsFR are compared with nonresponder GAT-Ts factor (GAT-TsF) and these responder and nonresponder GAT-TsF are considered in the context of suppressor pathways.
Clonal heterogeneity in the functional requirement for Lyt-2/3 molecules on cytolytic T lymphocytes: analysis by antibody blocking and selective trypsinization.
Authors: MacDonald H R , Glasebrook A L , Cerottini J C
Published: June 2004

While it is well established that murine cytolytic T lymphocytes (CTL) express the Lyt-2/3 molecular complex on their surface, conflicting results have been reported concerning the role of this complex in CTL activity. In the present study this question was reinvestigated at the clonal level. Although different (H-2b anti-H-2d) CTL clones expressed comparable amounts of Lyt-2/3 molecules, as assessed by quantitative flow microfluorometry, the activity of some clones was inhibited by low doses (10 ng) of monoclonal anti-Lyt-2 or anti-Lyt-3 antibodies (in the absence of complement), whereas other clones were not inhibited by either antibody at doses as high as 5 microgram. Treatment of these clones with doses of trypsin sufficient to cleave Lyt-2/3 antigenic determinants from the cell surface resulted in a similar dissociation: clones that were inhibited by antibodies lost cytolytic activity, whereas "uninhibited" clones were unaffected by trypsin treatment. Moreover, the dissociation observed among different alloreactive clones could be demonstrated with self-H-2-restricted (H-2b anti-MSV) clones exhibiting cross-reactivity with normal H-2d products. The lytic activity of these clones against the relevant syngeneic target cells was unaffected by anti-Lyt-2 antibodies or trypsin, whereas their cross-reactivity on H-2d target cells was abolished by either treatment. These results provide direct evidence for clonal heterogeneity in the requirement for Lyt-2/3 molecules in CTL-mediated lysis. It is proposed that the function of Lyt-2/3 molecules is to stabilize the interaction between CTL receptors and the corresponding antigens on the target cells and that the requirement for such a stabilization is correlated with low number and/or affinity of CTL receptors.
Surface antigens of melanocytes and melanomas. Markers of melanocyte differentiation and melanoma subsets.
Authors: Houghton A N , Eisinger M , Albino A P , Cairncross J G , Old L J
Published: June 2004

The surface antigens of melanocytes from newborn and adult skin have been analyzed with monoclonal antibodies detecting cell surface antigens of malignant melanoma. Antigenic markers that distinguish early, intermediate, and mature stages in melanocyte differentiation have been defined. The characteristics of the normal melanocyte precursor have been inferred from the features of melanomas that express early markers of melanocyte differentiation. A rudimentary surface antigen map of cells undergoing melanocyte differentiation and a new classification of melanomas based on the expression of melanocyte differentiation antigens are proposed.
Loss of stem cell repopulating ability upon transplantation. Effects of donor age, cell number, and transplantation procedure.
Authors: Harrison D E , Astle C M
Published: June 2004

Long-term functional capacities of marrow cell lines were defined by competitive repopulation, a technique capable of detecting a small decline in repopulating abilities. There was little or no difference between cells from old and young donors, but a single serial transplantation caused a large decline in repopulating ability. Varying the numbers of marrow cells transplanted into the initial carrier from 10(5) to 10(7) did not alter the ability of the carrier's marrow cells to repopulate in competition with previously untransplanted cells. This ability was improved only in carriers that had received 10(8) marrow cells, although deleterious effects of transplantation were still present. These effects were not solely caused by cell damage from the transplantation procedure, because transplantation by parabiosis, or recovery from sublethal irradiation without transplantation, reduced repopulating abilities as much as transplanting 10(5) to 10(7) marrow cells. The transplantation effect also was not caused solely by irradiation, because the same effect appeared in unirradiated W/Wv carriers. The transplantation effect was more pronounced when donors were identified by hemoglobin type than by chromosome markers, implying that nonerythroid cell lines may be less affected by transplantation than erythroid precursor cells. When the effects of a lifetime of normal function and a single transplantation were compared, the latter caused 3-7 times more decline in repopulating abilities of phytohemagglutinin-responsive cell precursors, and at least 10-20 times more decline in erythroid cell precursors. Stem cell lines can be serially transplanted at least five times before losing their ability to repopulate and save lethally irradiated recipients or to cure genetically anemic mice. Therefore, if transplantation causes an acceleration of the normal aging process, these figures suggest that stem cells should be able to function normally through at least 15-50 life spans.
Regulation of murine macrophage Ia antigen expression by a lymphokine with immune interferon activity.
Authors: Steeg P S , Moore R N , Johnson H M , Oppenheim J J
Published: June 2004

A culture supernatant of concanavalin A-activated spleen cells (Con A supernatant) induced murine macrophages to express Ia antigens in vitro. Biochemical characterization of the Con A supernatant indicated that the macrophage Ia antigen regulatory activity shares molecular weight, pI, and hydrophobic and affinity characteristics with immune interferon (IFN-gamma). Antiserum to mouse IFN-gamma neutralized both the macrophage Ia antigen regulatory and IFN-gamma bioactivities of the Con A supernatant. Furthermore, both partially purified murine IFN-gamma (10(7) U/mg protein sp act) and IFN-containing culture supernatants of the murine BFS T cell line-induced macrophage Ia antigen expression in vitro. Culture supernatants containing colony-stimulating factor, interleukin 1, interleukin 2, macrophage migration inhibitory factor, and a macrophage-activating activity that were distinct from IFN-gamma did not induce macrophage Ia antigen expression. Taken together, the data indicate that the in vitro expression of Ia antigens on macrophages is regulated by an activity that has the characteristics of interferon.
Primary cell-mediated lympholysis response to a maternally transmitted antigen.
Authors: Smith R , Huston D P , Rich R R
Published: June 2004

Mta-specific cytotoxic T lymphocyte (CTL) can be generated in primary cultures of (NZB X B10.D2)F1 spleen cells with H-2-compatible BALB/c stimulator cells. The CTL lyse reciprocal Mta+ (B10.D2 X NZB)F1 as well as H-2-disparate targets, such as B10, B6, and B6-Tlaa; they do not lyse targets from NZB or any F1 hybrid of an NZB mother. The lysis of 51Cr-labeled B10 targets is completely inhibited by unlabeled targets from Mta+ (B10.D2 X NZB)F1, but not from the reciprocal Mta- F1, thus demonstrating H-2-unrestricted lysis of Mta.
Human melanoma antigen AH is an autoantigenic ganglioside related to GD2.
Authors: Watanabe T , Pukel C S , Takeyama H , Lloyd K O , Shiku H , Li L T , Travassos L R , Oettgen H F , Old L J
Published: June 2004

AH antigen, initially defined by an antibody present in a melanoma patient, is a cell surface antigen found on approximately 65% of melanoma cell lines. Absorption analysis indicates that AH is a differentiation antigen marking normal and malignant cells of neuroectodermal origin. The AH determinant has been found to be related to GD2 ganglioside.
Combining site specificities of mouse hybridoma antibodies to dextran B1355S.
Authors: Newman B , Sugii S , Kabat E A , Torii M , Clevinger B L , Schilling J , Bond M , Davie J M , Hood L
Published: June 2004

The combining sites of 12 mouse hybridoma antibodies to dextran B1355S have been characterized by quantitative precipitin assay. All antibodies preferentially bind the immunizing antigen B1355S and two other class I dextrans, B1498S and B1501S, but show substantial differences in the extents to which they cross react with class I dextrans, suggesting their clustering into five groups. Three myeloma proteins, CAL20 TEPC1035, J558, and MOPC104E, which bind dextran B1355S, each fall into a different group. There appears to be a substantial, but imperfect, correlation of DH region structure and individual idiotypic determinants with dextran binding patterns. Proteins with RY DH segments and IdI (J558) idiotypes are in groups 1 or 3, and proteins with YD DH segments and IdI (MOPC104E) idiotypes are exclusively in group 5. However, identical patterns of precipitin curves accompany very different sequences in CDR3. Antibodies of group 1, which react only with class II dextrans, differ the most in primary sequence, a finding suggesting that subsites responsible for cross reactivity with class I dextrans may be blocked and that this may be effected by side chains of different amino acids. This finding delineates a new aspect of the relationship of variability in amino acid sequence to antibody complementarity.
The "Ly-1 B" cell subpopulation in normal immunodefective, and autoimmune mice.
Authors: Hayakawa K , Hardy R R , Parks D R , Herzenberg L A
Published: June 2004

A small subpopulation of normal murine splenic B cells carrying all of the classic B cells markers (IgM, IgD, Ia, and ThB) also carries Ly-1, one of the major T cell surface molecules. This "Ly-1 B" subpopulation (identified and characterized by multiparameter FACS analyses) consists of relatively large, high IgM/low-IgD/low-Ly-1 lymphocytes that represent approximately 2% of the spleen cells in normal animals and, generally, 5-10% of spleen cells in NZB mice. Ly-1 B are clearly detectable in all normal mouse strains tested as well as NZB, CBA/N, other X-id mice and nude (nu/nu) mice. They are found primarily in the spleen; are either absent or very poorly represented in lymph node, bone marrow, and thymus; appear early during ontogeny, and comprise about a third of the small number of lymphocytes present in 5-d-old mice. NZB and (NZB x NZW)F1 mice have more Ly-1 B than all other strains and, furthermore, have a unique Ly-1 B population that secretes IgM when cultured under usual conditions in the absence of added antigen. The IgM secretion by these Ly-1 B cells accounts for the previously reported "spontaneous" IgM secretion by NZB spleen cells in culture. Studies with FACS-sorted cells show that the presence of Ly-1 on these IgM-secreting cells distinguishes them from the (Ly-1 negative) IgM-secreting "direct" plaque-forming cells generated in NZB mice after stimulation with sheep erythrocytes.
Decreased glycolipid antigen expression in lymphoma cell variants escaping from anti-glycolipid serotherapy.
Authors: Young W W , Tamura Y , Johnson H S , Miller D A
Published: June 2004

Mice challenged with L5178Y lymphoma cells expression high levels of the glycolipid asialo GM2 (gangliotriosylceramide) were protected from tumor growth by passive administration of a monoclonal antibody specific for the glycolipid; in a few antibody-treated mice, ascites cells eventually proliferated which contained a reduced chemical quantity of the glycolipid antigen (3). We now report that the cells emerging from antibody-treated mice had abnormal marker chromosomes identical to those in the cells used for challenge, indicating that the emergent cells were progeny of the challenge inoculum. Flow cytometric analysis revealed that asialo GM2 was undetectable on the surface of greater than 95% of the tumor cells from antibody-treated mice, whereas surface display of H-2 determinants was unchanged from that of the cells used for challenge. Tumor cells arising in challenged but untreated mice consisted of a mixture of asialo GM2-positive and -negative cells, indicating the presence of selective pressures in these mice as well. None of the cells taken from tumor bearing mice differed significantly from the challenge cells in their susceptibility to natural killer cell attack, suggesting that resistance to natural killer cell lysis was not responsible for the proliferation of these cells in vivo. When cells derived from an antibody-treated mouse were used to challenge mice, serotherapy with anti-asialo GM2 had no effect on mouse survival. These results suggest that serotherapy may complement a host anti-tumor response, from which only asialo GM2 deficient cells can escape.