bluuebunny/crossref_metadata_2025_split huggingface dataset:
Occurrence of Complement Activation Specific Neonantigens on Peripheral Blood Leukocytes
Authors: Sundsmo J. S. , Kolb W. P. , Curd J. G. , Müller-Eberhard H. J. 
Published: January 2023

Abstract
Human terminal C complexes C5b-6, C5b-7, C5b-8, and C5b-9 express neoantigenic determinants (neoAg; Kolb, W. P. and Müller-Eberhard, H. J., Proc. Nat. Acad. Sci. 72, 1687, 1975). Complex-specific antiserum (anti-neoAg) detected neoAg on 27 ± 11% of viable human peripheral blood leukocytes (PBL) when prepared from defibrinated blood by Ficoll-Hypaque sedimentation. Specificity of anti-neoAg was established by immunodiffusion, by agglutination of EAC1-7, but not EA, E, or EAC4,2,3b, and by inhibition of EAC1-7 agglutination by C5b-9 complex. Specificity of the fluorescent staining reaction was established by inhibition of staining with C5b-9, but not with fresh serum, and by fluorescent staining of EAC1-7, but not EAC4,2,3b, EA, or E. In addition to neoAg, the individual components, C5, C6, C7, C8, and C9 were detected on PBL and the coincidence of C5 and neoAg on the same cells was 83%, and of C8 and neoAg 79%.
Characterization of the Primary IgM Response to Gat and GT: Conditions Required for the Detection of IgM Antibodies
Authors: Waltenbaugh Carl , Dessein Alain , Benacerraf Baruj 
Published: January 2023

Abstract
Primary IgM antibody responses to synthetic linear copolymers of L-glutamic acid, L-tyrosine, and L-alanine were investigated. The appearance of primary IgM anti-GAT antibodies was detected in BALB/c mice by using a solid phase radioimmunoassay (SPRIA) procedure. This finding was verified for GAT in responder mice and GAT-MBSA and GT-MBSA in nonresponder mice in an indirect plaque forming cell (PFC) assay by using a rabbit antiserum directed against the μλ myeloma protein, MOPC 104E. Facilitated IgM PFC could be inhibited by a purified μκ myeloma protein, TEPC 183. Maximal facilitated IgM plaque response was found to precede the IgG response by several days. A direct plaque assay was developed for the detection of IgM anti-GAT plaques using poly-L-lysine (PLL) to couple GAT to sheep erythrocytes (SRBC). GAT-SRBC coupled by the PLL method optimally couple 4 to 5 times less antigen to the indicator cell surface than does the CrCl3-coupling method routinely employed in our laboratory. These findings were extended to a conventional antigen, chicken gamma globulin (CγG). We found that a less dense epitope coat on the indicator cell surface favors detection of direct IgM PFC, whereas a more densely coated indicator cell favors the detection of facilitated IgM and IgG PFC responses.
The Identification of Actin as a Major Lymphocyte Component
Authors: Barber Brian H. , Delovitch Terry L. 
Published: January 2023

Abstract
Lymphocytes derived from pig mesenteric lymph node and mouse spleen have been shown to contain a major protein component which a) co-migrates on one-dimensional SDS-PAGE with purified pig muscle actin, and b) possesses the same isoelectric point as muscle action on two-dimensional gel electrophoresis. Further, limited proteolytic digestion of the lymphocyte actin-comigrating band by S. aureus V8-protease revealed extensive primary sequence homology with purified muscle actin. Based on the virtual identity of molecular size, charge, and primary sequence, we conclude that the actin-comigrating band represents lymphocyte actin. The appearance of lymphocyte actin as a nonspecific “contaminant” of immune precipitates has also been discussed.
Activation of the Classical Complement Pathway by Nephritic Factor Bound to the Alternative Pathway C3/C5 Convertase
Authors: Sobel Alain T. , Cooper Neil R. , Schreiber Robert D. 
Published: January 2023

Abstract
Nephritic Factor (NF), the potent alternative pathway activator, which is occasionally found in association with certain types of nephritis has recently been identified as an IgG class autoantibody specific for the C3 convertase of the alternative pathway. In these studies we have examined the possibility that the cell-bound NF-stabilized C3 convertase binds and activates the first component of the classical pathway of complement. bound C1q, and the extent of binding was dependent upon the number of NF molecules bound per cell and decreased parallel to the dissociation and release of NF from the cells. Interaction of C1 with bound NF resulted in its activation as shown by the proteolytic conversion of proenzyme C1s to its activated form C1s̅. As was the case with C1q binding, C1 activation was dependent on the number of NF molecules bound per cell. Thus the NF-stabilized C3 convertase binds and activates C1.
Comparisons of Myeloma Proteins from NZB and BALB/c Mice: Structural and Functional Differences of Heavy Chains
Authors: Loh E. , Hood J. M. , Riblet R. , Weigert M. , Hood L. 
Published: January 2023

Abstract
The N-terminal sequences from heavy variable regions of 47 myeloma proteins of the NZB mouse have been analyzed. Sixteen of these VH regions have unblocked α amino groups and have been analyzed over their N-terminal 20 residues by automatic sequence analysis. These sequence data along with the antigen-binding profiles and immunoglobulin class distribution are compared with comparable data from BALB/c myeloma proteins. These comparisons suggest that the NZB and BALB/c populations of myeloma proteins are distinct from one another. The genetic implications of this conclusion are discussed.
High Responder Rabbits to SRBC, a Familial Incidence
Authors: Bratcher Ray L. 
Published: January 2023

Abstract
Three litters of rabbits from our closed colony when immunized with multiple i.v. injections of SRBC gave unusually high titers compared to other rabbits immunized in a similar fashion. Data suggest that this response is a familial occurrence. The antisera from the high responding rabbits also exhibited other unique properties in addition to the high agglutinin titers. The early bleedings had significantly higher amounts of IgG anti-SRBC antibodies but similar amounts of IgM anti-SRBC antibodies relative to normal rabbits immunized with SRBC. The IgG antibodies from the high responders were low avidity antibodies and may exhibit limited heterogeneity.
Differences in the Behavior of the Membrane and Membrane-Associated Filamentous Structures in Normal and Chronic Lymphocytic Leukemia (CLL) Lymphocytes
Authors: Zucker-Franklin Dorothea , Liebes Leonard F. , Silber Robert 
Published: January 2023

Abstract
Ultrastructural studies of the membrane and membrane-associated cytoskeletal structures were carried out to help elucidate functional differences between normal and chronic lymphocytic leukemia (CLL) lymphocytes. A membrane-cross-linking ligand consisting of latex particles coated with anti-lymphocyte Ig permitted, because of its size, ultrastructural analysis of the site where the ligand had attached. In normal lymphocytes capped regions showed deep cytoplasmic invaginations and extensive polymerization of actin-like (7 nm) filaments in the adjacent submembranous zone. The presence of numerous bundles of intermediate filaments (10 nm) between the nucleus of the cell and the pole that carried the cap suggests a new role for these filaments in the capping process. CLL lymphocytes on the other hand showed deep cytoplasmic invaginations at sites of ligand binding over the entire cell surface. Actin-like filaments had also polymerized in the submembranous cytoplasm and had become attached to the plasma membrane by periodic cross bridges adjacent to these invaginations. However, organized arrays of intermediate (10 nm) filaments were not seen in CLL cells. Freeze-fracture studies after exposure of unfixed cells to glycerol revealed that the intramembranous particles (IMP) of normal lymphocytes had formed tight clusters whereas the IMP of CLL lymphocytes had either not been displaced at all or had formed only loose aggregates. This suggests the existence of a structural abnormality in the CLL Cell membrane that could interfere with IMP movement.
Helper Cells Activated by Allogeneic H-2K or H-2D Differences Have a Ly Phenotype Distinct from Those Responsive to I Differences
Authors: Swain Susan L. , Panfili Peter R. 
Published: January 2023

Abstract
Helper activity for the primary in vitro response to sheep erythrocytes was induced by recognition of foreign major histocompatibility antigens. The Lyt phenotypes of helper activity induced by differences in the whole haplotype, K or D antigens, I region antigen, or by differences at the M1s locus were determined. All allohelper cells expressed Ly1. In a single spleen cells suspension helper activity generated in response to the whole haplotype, I region, or M1s antigens was derived from an Ly2-negative population, whereas helper activity generated to K or D alone was derived from a population of Ly2-positive cells. Mixtures of anti-Ly1 and anti-Ly2 treated populations were unable to generate helper activity in response to K or D differences. Such helper activity was therefore dependent on the presence of Ly12 cells. It was concluded that the Ly phenotype of the helper cells is not determined solely by the T cell function but is influenced by the region of the major histocompatibility complex that is recognized. Possible interpretations of these findings are discussed.
Terminal Deoxynucleotidyl Transferase (TdT) in Chick Embryo Lymphoid Tissues
Authors: Sugimoto Masanobu , Bollum F. J. 
Published: January 2023

Abstract
The development of terminal deoxynucleotidyl transferase (TdT) was studied in the thymus and other lymphoid organs of embryonic and post-hatch chickens with an immunofluorescent procedure based on anti-TdT IgG purified on an immunoabsorbent column. TdT-positive cells were virtually absent in the thymus on day 11 of embryonic development and first became detectable on day 12. These cells then increased linearly to attain a plateau level of approximately 70% at about day 19. TdT-positive cells displayed network staining in the nucleus and some cytoplasmic staining. Most TdT-positive thymocytes were small, compared to TdT-negative cells.
A few TdT-positive cells (fewer than 1/105) were observed in the bursa of Fabricius in 20-day embryonic and 3- and 8-day post-hatch chickens. Positive cells were extremely rare in both the spleen and bone marrow. The brain and liver were TdT-negative.
These observations suggest that TdT-positive cells differentiate in situ from TdT-negative lymphoid cells in the thymus of embryonic chickens. The possible relationship of TdT to immune function is supported by the correlation of the kinetics of TdT-positive cell development in the present experiment with earlier observations on the morphologic, serologic, and functional development of embryonic chicken thymocytes.
Generation of T Helper Cells in Vitro
Authors: McDougal J. S. , Shen F. W. , Elster P. 
Published: January 2023

Abstract
In the thymocyte-macrophage (T-Mø) culture system for the in vitro induction of murine T helper cells, cortisone-resistant, nylon wool-purified thymocytes (CRNPT) are cultured with macrophages from antigen-primed donors. The particulate antigens, sheep erythrocytes (SRBC) or vaccine prepared from cell walls of Group A Streptococcus (SAV), were used to prime T-Mø cultures. The native CRNPT population contained Ly1, Ly23, and Ly123 cells in the proportions 45:3:46, but after 4 days of culture with antigen-pulsed macrophages the proportions were 88:2:2. The Ly1 T cell populations selected from such cultures by treatment with anti-Ly2 serum plus complement exhibited antigen-specific helper or suppressor functions in vitro, depending on the mode of the PFC assay: when assayed for their effect on T celldepleted spleen populations, helper function was manifest; when assayed with intact spleen cell populations, suppression was manifest. Our data do not indicate whether these two functions are mediated by the same Ly1 cells or by two subpopulations of Ly1 cells. The generation of Ly1 helper cells from CRNP thymocytes in 4-day T-Mø culture required the initial presence of the Ly123 members of this population. Manifestation of suppression by the same Ly1 population required the presence of Ly123 cells in the splenic populations used for PFC assay.
Cytotoxic Cells Induced During Lymphocytic Choriomeningitis Virus Infection of Mice
Authors: Welsh Raymond M. , Zinkernagel Rolf M. , Hallenbeck Linda A. 
Published: January 2023

Abstract
The target specificities of natural killer (NK) cells induced in mice by lymphocytic choriomeningitis virus (LCMV) were examined. All continuous and early passage cell lines tested were lysed by LCMV-induced NK cells, regardless of the target cell's origin (syngeneic, allogeneic, xenogeneic) or morphology (epithelia, fibroblast, lymphoblast, neuroblast, teratoma). Continuous cell line targets were lysed by LCMV- or vaccinia virus-induced NK cells from all tested strains of mice. Some target cells were more sensitive to lysis than other targets, but this relative sensitivity did not vary with the strain of mouse donating the effectors or with the time after inducing NK cells by the virus infection. LCMV-induced NK cells did not appear to recognize LCMV antigens on the surface of infected cells, nor could any correlation be made between retrovirus antigen expression and susceptibility to lysis. In contrast to this apparent lack of specificity in lysing continuous cell lines, we confirmed that some specificity could be demonstrated by using cold target inhibition experiments.
When primary peritoneal cells were used as targets, LCMV-induced NK cells from different strains of mice had restricted ranges of target specificities. NK cells from most homozygous mice lysed heterologous cells at much higher efficiency than isologous cells, but susceptibility to lysis was not directly related to H-2. In some strains of mice both isologous and heterologous targets were lysed. Spleen cells from F1 hybrid mice of certain strains lysed target cells from either parental strain. NK cell-mediated lysis of primary peritoneal cell targets did not require exogenous serum sources and was not significantly influenced by the presence of unlabeled target cells with varied susceptibilities incorporated into cytotoxicity assays.
We hypothesize that there may be two types of recognition mechanisms of the NK cell population: one that is “nonspecific,” resulting in the lysis of continuous or transformed cells, and another that is “specific,” resulting in a more selective lysis of primary cells. The vague specificities sometimes demonstrated against continuous cell targets by cold target inhibition experiments could be explained if the continuous cell line targets also expressed the specific recognition sites found on primary cells.
Mouse C4 (Ss): Three-Step Purification of Its C4c Fragment and Production of a Monospecific Antiserum
Authors: Ferreira Arturo , Nussenzweig Victor 
Published: January 2023

Abstract
We report here that a large fragment of mouse C4 (C4c) can be easily purified from serum with good recoveries, and used to produce a monospecific antiserum. The method of isolation of C4c is based on the observation that C4 is easily activated and fragmented in mouse serum. The fragments bind to the C4-binding protein (C4-bp), a newly described macromolecular component of the complement system. The high m.w. complexes were precipitated by dialysis of the serum against 0.1 M acetate buffer, pH 5.0, and purified by passage of the dissolved precipitate through a Sephadex G-200 column. The complexes were dissociated at high salt concentration, and the C4 fragments were isolated by passage of the mixture through a second Sephadex G-200 column. One of the C4 fragments (C4c) was used to immunize rabbits, and a monospecific antiserum was obtained, which showed a reaction of identity between C4 and Slp. Therefore the C4c fragment of C4 and the Slp protein are structurally related.
Establishment and Characterization of BALB/c Lymphoma Lines with B Cell Properties
Authors: Kim K. Jin , Kanellopoulos-Langevin Colette , Merwin Ruth M. , Sachs David H. , Asofsky Richard 
Published: January 2023

Abstract
Five spontaneously derived BALB/c tumors and one 1-ethyl-1-nitrosourea induced BALB/c tumor (BALENLM 17), have been established in culture and characterized according to their surface markers. K46, X16C, L10A, and BALENLM 17 are IgM+, IgG-, IgA-, Ig+ (staining with polyvalent anti-Ig), Ia+, Fc receptor+ and complement receptor-. A20 is IgM-, IgG-, IgA-, Ig+, Ia+, Fc receptor+, and complement receptor-. M12 is IgM-, IgG-, IgA-, Ig±, Ia-, Fc receptor+ and complement receptor-. All these lines are Thy 1.2 antigen negative, do not phagocytize latex particles, and grow as stationary suspension cultures. Therefore these six BALB/c lymphoid lines are presumably of B cell origin at various stages of differentiation. All these lines except X16C are tumorigenic in mice within a short period of time and have relatively short generation times in the range of 18 to 26 hr. Karyotype studies show that L10A, K46, X16C, and BALENLM 17 are hyperdiploid to hypotetraploid. A20 and M12 have near diploid chromosome numbers.
Killing of Schistosomula of Schistosoma Mansoni Coated with Antibody and/or Complement by Human Leukocytes in Vitro: Requirement for Complement in Preferential Killing by Eosinophils
Authors: Anwar A. R. E. , Smithers S. R. , Kay A. B. 
Published: January 2023

Abstract
The capacity of human eosinophils, neutrophils, and mononuclear leukocytes to damage schistosomula coated with antibody and/or complement has been studied by using an in vitro assay in which helminth destruction was visualised directly. Schistosomula and leukocytes were incubated either with i) antibody (Ab) alone (as baboon anti-schistosomula serum, or serum from patients with schistosomiasis or its IgG fraction); ii) complement (C) alone (by incubating schistosomula with fresh serum that led to activation by the tegument of the alternate pathway of complement as shown by immunofluorescence with anti-C3, but not anti-C4, both with normal and C2-deficient serum); or iii) the combination of Ab and C.
The efficiency of killing of schistosomula by granulocytes (i.e., mixtures of eosinophils and neutrophils) was 31 ± 7% for Ab alone, 52 ± 9% for C alone, and 70 ± 8% for Ab + C; control preparations were approximately 14%. Equivalent numbers of mononuclear leukocytes gave 22 ± 3%, 31 ± 5%, and 37 ± 4% killing with Ab alone, C alone, or Ab + C, respectively.
Schistosomula killing was directly related to the concentration of antibody with Ab alone and to the dilution of complement with C alone and Ab + C. Damage by granulocytes or mononuclear leukocytes was dependent on the ratio of effector cells to schistosomula in the three experimental systems.
Granulocyte-dependent damage was enhanced by the sequential addition, to schistosomula sensitized with antibody, of purified components of the classical pathway of complement and was directly related to the input of C3. This observation, together with the direct visualisation of C3 by immunofluorescence, suggests the participation of the classical pathway of complement in the Ab + C system.
Immunogenicity of Liposomal Model Membranes Sensitized with Dinitrophenylated Phosphatidylethanolamine Derivatives Containing Different Length Spacers
Authors: Dancey George F. , Isakson Peter C. , Kinsky Stephen C. 
Published: January 2023

Abstract
The immunogenicity of liposomes sensitized with dinitrophenylated (DNP) phosphatidylethanolamine (PE) derivatives, differing in the length of the spacer linking DNP to PE, has been examined. The magnitude of the anti-DNP response of mice was influenced by the number of methylene and amino groups interposed between DNP and the amino function of PE; generally, derivatives containing very short or long spacers were less effective immunogens than those of intermediate length. The epitope density of the derivative in the lipid bilayers, but not the dose, also affected the relative immunogenicity of the different derivatives. Incorporation of lipid A, which has been previously demonstrated to enhance liposomal immunogenicity, increased the response to those derivatives that elicited antibodies in the absence of this polyclonal B cell mitogen; however, the relative immunogenicity of the derivatives was not significantly altered. A good correlation was observed between the ability to bind low affinity IgG and IgM antibodies in vitro (determined by complement-dependent glucose release from liposomes) and in vivo immunogenicity. These results suggest that the ability of sensitized liposomes to elicit a response requires the extension of the antigenic determinant away from the surface of the lipid bilayer.
Early Stages of Human Marrow Lymphocyte Differentiation: Induction in Vitro by Thymopoietin and Ubiquitin
Authors: Kagan Walt A. , Siegal Frederick P. , Gupta Sudhir , Goldstein Gideon , Good Robert A. 
Published: January 2023

Abstract
To study early stages of human lymphocyte differentiation, bone marrow cells were physically separated according to their density and size by gradient centrifugation and then velocity sedimentation. The isolated cell fractions were incubated with putative inducing agents and then assayed for their expression of an array of surface differentiation markers. The inducing agents used were two polypeptides, thymopoietin (Tp) and ubiquitin (Ub), and the cyclic nucleotide, dibutyril cyclic 3′5′ adenosine monophosphate (cAMP). Tp, Ub, and cAMP each induced the ability to form sheep erythrocyte rosettes by small lymphocytes, which may thus represent T cell precursors. Ub and Tp induced rosette formation with mouse erythrocytes on lymphocytes of more heterogenous size, which may be “early” B cell precursors. Ub alone could induce surface IgM expression on small lymphocytes, which might be “late” B cell precursors. Both Tp and Ub induced Fc receptors on small lymphocytes. Complement receptors could not be induced on marrow lymphocytes by Tp, Ub, or cAMP. A number of lymphocyte precursors can thus be identified by their physical characteristics and their ability to respond to particular soluble factors with the expression of new differentiation markers.
Characterization of Thymus-Derived Lymphocyte Subsets in Acute Epstein-Barr Virus-Induced Infectious Mononucleosis
Authors: Haynes Barton F. , Schooley Robert T. , Grouse Jan E. , Payling-Wright Charles R. , Dolin Raphael , Fauci Anthony S. 
Published: January 2023

Abstract
Changes in thymus-derived (T) lymphocyte subpopulation numbers were studied in patients with acute and convalescent Epstein-Barr virus (EBV)-induced infectious mononucleosis (IM). T cell subsets were characterized by the presence of Fc receptors for IgG (TG), for IgM (TM) or by the absence of either receptor (Tnon-M, non-G). We found that in acute IM, total numbers of T and B lymphocytes were elevated (p &lt; 0.01). Of the T lymphocyte subsets, the total number of Tnon-M, non-G lymphocytes was increased six fold compared to normal subjects (p &lt; 0.001) and included the majority of the atypical T lymphocytes. The number of total TG and TM lymphocytes was moderately increased (p &lt; 0.05). In convalescent IM patients, the number of total T cells remained slightly elevated (p &lt; 0.02) whereas proportions and absolute numbers of B lymphocytes and T cell subsets returned to near normal levels. Thus, acute Epstein-Barr virusinduced IM is associated with a T lymphocytosis which is composed predominantly of atypical T cells which lack detectable Fc receptors for IgG or IgM.