bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunoglobulin heavy chains from anti-inulin myeloma proteins: evidence for a new heavy chain joining segment.
Authors: Rudikoff S , Potter M 
Published: December 2022

Abstract
Immunoglobulin heavy chains have been shown to be encoded by at least 3 widely separated genetic elements, designated variable (V), diversity (D), and joining (J), which undergo rearrangement during somatic differentiation to produce the active gene form. The D segment codes for a portion of the 3rd hypervariable region and thus potentially contributes significantly to structural diversity in this portion of the molecule. Heavy chains from anti-inulin proteins are unusual in that they essentially lack a 3rd hypervariable region. Thus, if a D segment exists in these proteins, it is extremely short, possibly 1 to 2 amino acids, and more likely serves a framework function rather than introduces structural diversity in the 3rd hypervariable region. We have completed the heavy chain variable region amino acid sequence from proteins AMPC1 and T957 bringing to 6 the number of complete sequences from this group. All of these proteins lack a 3rd hypervariable region. In addition, substitutions are found within the J segments of AMPC1 and T957, which are unlikely to be generated by the recombination event. The occurrence of Pro at position 105 in both of these J segments in contrast to the Gln found in all other heavy chains using this J segment suggests the possible existence of a previously unidentified J segment gene.
In vivo effects of anti-asialo GM1. I. Reduction of NK activity and enhancement of transplanted tumor growth in nude mice.
Authors: Habu S , Fukui H , Shimamura K , Kasai M , Nagai Y , Okumura K , Tamaoki N 
Published: December 2022

Abstract
Intravenous injection of anti-asialo GM1, which has been shown to eliminate natural killer (NK) activity in vitro in the presence of complement, completely abolished NK activity against lymphoma cell line (YAC-1) in spleen cells from athymic nude mice as well as from conventional mice. An immunofluorescence study revealed a decreased number of asialo GM1 positive cells in the spleens of mice injected with anti-asialo GM1 than in those of mice injected with normal rabbit serum. In the nude mice with reduced NK activity, incidence of tumor take and the growth were enhanced when syngeneic (RL male-1), and allogeneic (YAC-1) tumors and human tumors were transplanted subcutaneously. These results strongly suggest that NK cells play an important role in transplanted-tumor growth in vivo.
The membrane attack mechanism of complement: photolabeling reveals insertion of terminal proteins into target membrane.
Authors: Hu V W , Esser A F , Podack E R , Wisnieski B J 
Published: December 2022

Abstract
We have utilized a membrane-restricted, photoactivable glycolipid probe to investigate the protein-lipid interactions involved in complement (C) mediated lysis of a target membrane. The purified C proteins C5b-6, C7, C8, and C9 were added to artificial membrane vesicles containing the 14C-labeled photoreactive probe anchored in the outer monolayer of the membrane, and 6-carboxyfluorescein trapped in the lumen as an indicator for effective lysis. Irradiation of the membrane samples at different stages of functional complex assembly resulted in labeling of each of the 5 terminal C proteins, indicating that all 5 proteins become inserted into the hydrophobic milieu of the membrane during some stage of complex assembly. However, at the final stage of complex assembly, only C9 appeared to be labeled. Because we can demonstrate that the photoreactive probe has no strong affinity for C9 over the other terminal components (C5b-C8), the extensive change in labeling specificity during assembly is evidence for substantial changes in protein-lipid and possibly protein-protein interactions during formation of the C lesion.
Specificity of H-2-linked Ir gene control in mice: demonstration of T helper cells recognizing branched synthetic polypeptides in low responder mice.
Authors: Stötter H , Imm A , Meyer-Delius M , Rüde E 
Published: December 2022

Abstract
This report provides evidence for the presence of T helper cells capable of recognizing the polypeptide antigens T6-A--L and (H,G)-A--L in low responder mice of H-2k and H-2b haplotypes, respectively. Mice were primed in vivo with the T6-A--L-avidin-(H,G)-A--L complex or, in the case of T6-A--L in H-2k mice, with the cross-reactive and permissive antigen T6-S--L. T helper cells cooperating with DNP-primed B cells could be rechallenged in vitro with the DNP-conjugates of T6--A--L or (H,G)-A--L, although the cells were of low responder type with respect to these antigens. This implies that T cell-macrophage interaction required for restimulation is apparently not defective in these low responders. The implications of these results for the concept of Ir gene control are discussed.
Suppression of phagocytosis and chemotaxis by cell wall components of Staphylococcus aureus.
Authors: Musher D M , Verbrugh H A , Verhoef J 
Published: December 2022

Abstract
The ability of S. aureus to resist phagocytosis by polymorphonuclear leukocytes (PMN) is thought to be an important virulence factor for this microorganism. We have studied the effect of 3 major cell wall components of S. aureus, peptidoglycan, protein A, and teichoic acid, on PMN function. Phagocytosis and chemotaxis were both inhibited by prior incubation of PMN with peptidoglycan. This effect was dose- and time-related; incubation with as little as 2.5 micrograms/ml for 30 min produced a discernible suppressive effect. Suppression of PMN function was independent of the presence of human serum but was abolished by rabbit antiserum to peptidoglycan. Addition of peptidoglycan to PMN stimulated a prolonged chemiluminescence response that was greater when the peptidoglycan was first incubated in normal serum, perhaps reflection opsonization of this particulate material. Although protein A also suppressed phagocytic and chemotactic capabilities of PMN, this effect was observed only in the presence of serum and was eliminated by absorbing Ig. Centrifugation of the serum + protein A mixture showed that the suppressive effect was contained in the precipitated sediment. Complexes of Ig alone were not suppressive. Teichoic acid in concentrations less than or equal to 100 micrograms/ml had no adverse effect on PMN function. These studies describe ways in which peptidoglycan and protein A may interfere with phagocytosis and chemotaxis of human PMN, thus giving evidence for the role of these cell wall components as virulence factors.
T cell-replacing factor- (TRF) induced IgG secretion in a human B blastoid cell line and demonstration of acceptors for TRF.
Authors: Muraguchi A , Kishimoto T , Miki Y , Kuritani T , Kaieda T , Yoshizaki K , Yamamura Y 
Published: December 2022

Abstract
IgG-secretion was induced in a human B blastoid cell line, CESS, by the addition of partially purified T cell-derived helper factor(s) (TRF), which had been obtained from PHA-stimulated human T cells. The number of IgG-producing cells in CESS cells reached its maximal level (10% of total cells) within 48 hr after the addition of TRF. TRF did not affect the proliferation of CESS cells and the block of cell proliferation with hydroxyurea did not inhibit the increase of IgG-producing cells, showing that TRF induced IgG-production in CESS cells without any requirement of cell division. TRF activity was completely removed by CESS cells but TCGF-activity in the same preparation was not absorbed with CESS cells. On the other hand, TCGF-dependent human killer cells absorbed TCGF activity but not TRF activity in the same preparation. The binding of 125I-labeled factor(s) on CESS cells was also demonstrated. These results showed the presence of acceptors for TRF on the surface of CESS cells and this cell line will provide useful means for the chemical characterization of acceptors and for the study of the mechanisms of the signal transmission through acceptors.
Proteolysis of the monomeric and dimeric C5b-9 complexes of complement: alteration in the susceptibility to proteases of the C9 subunits associated with C5b-9 dimerization.
Authors: Yamamoto K , Migita S 
Published: December 2022

Abstract
The C5b-9 monomer having the sedimentation coefficient of 23S was extracted from the rabbit erythrocyte membranes that had been treated with a limiting amount of C9-deficient human serum and of 125I-C9. Upon proteolysis by trypsin and chymotrypsin, the C9 subunits of this complex were cleaved by these enzymes at multiple sites, yielding fragments with m.w. ranging fro 40,000 to 19,000. The uncomplexed C9 was also cleaved by both enzymes at multiple sites. By contrast, the C9 subunits of the C5b-9 dimer were found to be totally insusceptible to chymotrypsin under the conditions studied (37 degrees C; 24 hr) and only partially susceptible to trypsin (33% of the C9 subunits were cleaved by trypsin into 2 fragments during incubation at 37 degrees C for up to 24 hr). Therefore, these results indicate that, although the binding of C9 molecules to the C5b-8 complex (C5b-9 monomer formation) does not significantly affect the susceptibility to proteases of the C9 molecules, C5b-9 dimer formation markedly limits the accessibility of proteases to the C9 subunit molecules. A implication of this finding to a role for C9 in C5b-9 dimerization is discussed.
Lymphocyte collaboration is required for induction of murine monocyte procoagulant activity by immune complexes.
Authors: Schwartz B S , Edgington T S 
Published: December 2022

Abstract
Both aggregated IgG and soluble immune complexes composed of human serum albumin and specific antibody at a 4:1 ratio were demonstrated to rapidly induce an increase in procoagulant activity (PCA) of murine peripheral blood mononuclear cells. Direct cytologic assays as well as fractionation of cells by adherence to plastic established the monocyte as the cell producing PCA, and demonstrated further that almost all monocytes, rather than a subpopulation, participated in the response. Monocytes that were depleted of lymphocytes did not respond to these stimuli with production of PCA; that is, induction of monocyte PCA was observed only when stimulation was performed in the presence of lymphocytes. Induction was equally efficient when only the lymphocyte was stimulated by aggregated IgG or soluble immune complexes, washed free of unbound stimulus, and added to monocytes. This suggests a unidirectional pathway by which the stimulus triggers lymphocytes after which there is direct lymphocyte-mediated induction of monocytes to produce PCA. Evidence for participation of soluble lymphocyte products was not obtained, and it is suggested that this series of events may be mediated by direct lymphocyte contact with responding monocytes. The role of this pathway in the genesis of immunologically initiated tissue lesions is discussed.
Characterization and isolation of IgE class-specific suppressor factor (IgE-TsF) I. The presence of the binding site(s) for IgE and of the H-2 gene products in IgE-TsF.
Authors: Suemura M , Shiho O , Deguchi H , Yamamura Y , Böttcher I , Kishimoto T 
Published: December 2022

Abstract
IgE-specific reverse plaque assay for the direct comparison of the IgE and IgG antibody responses was established and the method was employed for the assessment of the activity of IgE class-specific suppressor factor (IgE-TsF). In the in vitro culture system, the addition of IgE-TsF to DNP-KLH-primed spleen cells inhibited an antigen-induced increase of IgE-producing cells but did not show any effect on the IgG or IgM responses. Absorption of IgE-TsF with IgE-producing hybridoma cells removed the suppressor activity but IgM-producing hybridoma cells did not absorb the suppressor activity. The suppressor activity of IgE-TsF was removed by murine IgE-conjugated Sepharose column but not by IgM-, IgG-, or human IgE-conjugated column. The suppressor activity was eluted from IgE-column with glycine-HCI buffer, pH 3.2, or acetate buffer, pH 4.0, and the suppressor factor eluted from IgE-column was reabsorbed by anti-H-2d conjugated column. The results showed that IgE-specific suppressor factor was composed of the binding sites for IgE molecules and the H-2 gene products.
Anti-immunoglobulin antibodies. II. Expression of individual and cross-reactive idiotypes on syngeneic and homologous anti-idiotype antibodies.
Authors: Bona C , Kearney J 
Published: December 2022

Abstract
Syngeneic anti-(anti-Id) antibodies were prepared against BALB/c anti-A48Id antibodies, BALB/c anti-460Id monoclonal antibodies, and A/J anti-J558 IdI monoclonal antibodies. With these anti-(anti-Id) antibodies we identified cross-reactive idiotypes on syngeneic and homologous anti-A48Id and anti-460Id antibodies. By contrast, tbe idiotypic determinants of A/J anti-J558 IdI monoclonal antibodies were not shared by other syngeneic, homologous, or xenogenic anti-J558 IdI or IdX antibodies. These results suggest that idiotype-antiidiotype reactions that serve as regulatory controls within the immune system are characteristic for each particular antigen system, strain, or species and that such interactions make the system self-limited with respect to the whole antild repertoire.
Flow microfluorometric analysis of H-2L expression.
Authors: Potter T A , Hansen T H , Habbersett R , Ozato K , Ahmed A 
Published: December 2022

Abstract
The cell surface expression of H-2L, a major transplantation antigen, was compared by flow microfluorometry to the expression of products of H-2K and H-2D loci, using monoclonal antibodies. By this methodology, the ontogeny and tissue distribution of Ld antigens were found to be indistinguishable from those of the K and D antigens. In a reciprocal blocking assay, using fluorescein-labeled test reagents, it was shown that monoclonals anti-H-2.65 and anti-H-2.64 did not inhibit the binding of each other. These results suggest that the alloantigenic determinants H-2.64 and H-2.65 are located at distinct sites on Ld molecules. Quantitative comparisons using the fluorescein-labeled monoclonal reagents indicated that Ld molecules are expressed at 2- to 3-fold lower levels on the cell surface compared with K and D molecules. These findings give new credence to a "3-locus" model for the major histocompatibility complex of man and mouse, where H-2L and HLA-C share several homologies that are unique and distinguish them from the other histocompatibility loci.
A fourth heavy chain variable region subgroup, w, with 2 variants defined by an induced auto-antiserum in the rabbit.
Authors: Roux K H 
Published: December 2022

Abstract
An antiserum recognizing previously undescribed antigenic determinants (designated subgroup w) of the heavy chain VH region was produced by immunizing a rabbit, homozygous for the VH haplotype a1x-y- with IgG from another a1x-y- rabbit, suppressed for a1. The antiserum gives a single fused precipitin band against sera from homozygous rabbits suppressed for the a1, a2, or a3 allotypes. By gel diffusion analysis, the determinant was found to be distinct from previously described a, x, and y allotypes, and was detectable on IgG, F(ab')2 gamma and the gamma-heavy chain. Radioinhibition analysis revealed 2 patterns of inhibition suggesting 2 variants of w that are closely linked to VH allotypes. Variant w34 was detected at very low levels (0.042 to 5.6 micrograms/mg IgG) in normal rabbits expressing the a1x-y-, a1-y33,30, and a3x32y- VH haplotypes. Variant w35 was detectable in a 2x32y33,- rabbits. Sera from homozygous a allotype-suppressed rabbits representing each of the 4 VH haplotypes similarly exhibited either w34 or w35 patterns of inhibition as described above. The level of w34 in a1- and a3-suppressed rabbits exhibited a dramatic 230-fold median increase. In contrast, w35 levels for a2-suppressed rabbits fell within the normal range. In addition to reacting with essentially all normal and suppressed sera, the antiserum reacted with preimmune serum from the same rabbit. Thus, anti-w represents an induced auto-antibody. These observations are further discussed with regard to rabbit and mouse VH populations.
Transplantation in miniature swine. IX. Swine histocompatibility antigens: isolation and purification of papain-solubilized SLA antigens.
Authors: Metzger J J , Gilliland G L , Lunney J K , Osborne B A , Rudikoff S , Sachs D H 
Published: December 2022

Abstract
Histocompatibility antigens have been purified by papain treatment of crude cellular membranes obtained from spleen and mesenteric lymph nodes of individual miniature swine that are homozygous at the major histocompatibility complex. The purification protocol included ultracentrifugation, gel filtration, ion-exchange chromatography, and in some instances preparative isoelectric focusing. This procedure was applied to the preparation of sLA antigens from the 3 haplotypes available in our partially inbred miniature swine herd. The purity of the SLAdd molecules was evidenced by: 1) a single activity peak of approximately 50,000 daltons on gel-permeation chromatography; 2) the antigen elution as a symmetrical peak from ion-exchange resins and from isoelectric focusing columns; 3) the presence of 2 predominant polypeptide chains on SDS-PAGE at apparent m.w. 43,000 and 13,000 daltons; and 4) specific immunoprecipitations by alloantisera and by anti-beta 1 microglobulin antisera. The antigenic activity of SLA products was analyzed by inhibition of complement-mediated cytotoxicity and by removal on anti-beta 2-microglobulin affinity columns. Heavy and light chains were separated by gel-filtration on Sephacryl S-200 in 6 molar guanidine. These SLA products, which have thus been shown to be pure by a variety of criteria, are now readily available for structural analysis and for analysis of biologic activity.
Long-term in vitro culture of murine mast cells. I. Description of a growth factor-dependent culture technique.
Authors: Tertian G , Yung Y P , Guy-Grand D , Moore M A 
Published: December 2022

Abstract
A feeder layer independent long-term in vitro culture system for murine mast cells is described. Concanavalin A-activated murine splenic leukocyte-conditioned medium, prepared under conditions optimal for T cell growth factor production, has been found also to contain a growth-promotion activity for murine mast cells identified by their morphology, characteristic ultrastructure of the granules, positive reactions with toluidine blue and alcian blue, presence of receptors for IgG and IgE, as well as presence of histamine, serotonin, L-Dopa, 5-hydroxytryptophan, and sulfated products within the cytoplasm. After 2 to 3 wk of culture in the presence of the conditioned medium, mast cell lines were established from various sources initially devoid of matured mast cells. Such sources included spleen and bone marrow of athymic nude mice, long-term cultured marrow cells as well as T cell-depleted normal marrow. Cultured mast cells are absolutely dependent upon the conditioned medium-derived growth factor(s) for growth and viability. Death ensues within 24 hr in the absence of the factor(s). Established mast cell lines have been maintained in exponential growth for over 1 yr by passaging in the conditioned medium every 3 to 7 days.
Induction of human immunoglobulin secretion. I. Synergistic effect of B cell mitogen Cowan I plus T cell mitogens or factors.
Authors: Saiki O , Ralph P 
Published: December 2022

Abstract
Synergistic effects of B cell mitogen Staphylococcus bacteria strain Cowan I (Cowan I) plus T cell mitogens in generating immunoglobulin-secreting cells (ISC) from human peripheral blood mononuclear cells (MNC) were investigated. ISC were assayed by reverse plaque-forming cells with protein A-coated red blood cells. Low concentrations of pokeweed mitogen (PWM) plus Cowan I gave superadditive effects on ISC induction, generating 3 to 10 times as many ISC as optimal amounts of either mitogen alone. The mitogens together and separately showed similar kinetics of ISC; synergy was observed at every day tested. Plaque-forming cells of IgM, IgG, and IgA classes all showed strong synergy, together routinely representing 20% of initial MNC. At day 7 of culture, over 80% of non-E-rosetting cells were ISC. Cell donors tested gave these strong responses even if they were low responders to either mitogen alone. Cowan I plus other T cell mitogens, PHA, Con A, and protein A, also provided good signals for B cell activation. Cowan I induced marked proliferation of purified B cells, but T cell-helper signals were required for differentiation to ISC. T cell-helper factor, induced by PWM or PHA, also showed synergistic effects with Cowan I in induction of ISC. Purified B cells did not respond to T cell-helper factor(s) alone to proliferate or differentiate to ISC. These results indicate that optimal ISC induction occurs with a B cell mitogen plus T cell signals acting synergistically.
Characterization of phosphorylcholine- (PC) specific IgE-B cells in CBA/N or (CBA/N x BALB/c)F1 male mice.
Authors: Shigemoto S , Kishimoto T , Yamamura Y 
Published: December 2022

Abstract
Surface immunoglobulin isotype of precursors for PC-specific IgE response in CBA/N or NBF1 male mice was studied. Immunization of CBA/N or NBF1 male mice, which had been lethally irradiated and reconstituted with KLH-primed syngeneic spleen cells, with PC-KLH induced the PC-specific IgE, but not the IgM, response. Depletion of mu-bearing cells from KLH-primed spleen cells completely abolished the induction of the anti-PC IgE response. Depletion of T15 idiotype-bearing cells with anti-T15-coated dishes also abrogated the anti-PC IgE response in NBF1 male mice. Mice that were transferred with delta- or epsilon-bearing cell-depleted cell populations did not show the anti-PC IgE response on day 14, but they showed the anti-PC IgE response on day 21. These results indicated that PC-specific IgE-producing cells in CBA/N mice, which were defective in the anti-PC IgM response, were derived from PC-specific mu-bearing cells, and direct precursors bore mu, delta, and epsilon on their surface.
Increased natural killer cell activity in experimental American trypanosomiasis.
Authors: Hatcher F M , Kuhn R E , Cerrone M C , Burton R C 
Published: December 2022

Abstract
These studies showed that increased natural killer (NK) cell activity develops during experimental American Trypanosomiasis in mice. Increased cytotoxicity against YAC target cells by peritoneal cavity cells (PEC) was detected as early as 1 day into infection in both C3H/He and C57BL/6 mice. Peak activity occurred 2 days into infection, with significant but variable increases detected in the spleen cells (SC) from these mice. The response subsided in PEC and to a lesser extent in SC by 4 days post-infection. Similar responses were not detected in infected C57BL/6 bgJ/bgJ (beige mutant) mice until the fourth day of infection and peaked at significantly lower levels than the peak on day 2 in beige hybrid mice ([C57BL/6 +/+ X C57BL/6 bgJ/bgJ]F1). The effector cell from infected mice was sensitive to pretreatment with anti-NK 1.2 serum plus complement (C), partially sensitive to anti-Thy 1.2 + C, and insensitive to polyvalent anti-mouse immunoglobulin + C. The cytotoxic activity induced in cells from mice infected for 2 days was recovered in subpopulations nonadherent to plastic or Sephadex G-10. Thus, the anti-YAC effector cell found very early in mice infected with T. cruzi possessed many of the characteristics of natural killer (NK) cells found in normal mice. Other experiments demonstrated that injection of heat-killed preparations of blood-form trypomastigotes (BFT) induced increases in NK activity. The presence of augmented NK activity against YAC tumor cells in both resistant and susceptible strains of mice, together with the presentation of the resistance phenotype in beige mutant mice, which had a lower NK response to infection, is not indicative of a direct role for host protection during infection with T. cruzi by NK cells.