bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monoclonal antibodies to two determinants of melanoma-antigen p97 act synergistically in complement-dependent cytotoxicity.
Authors: Hellström I , Brown J P , Hellström K E 
Published: December 2022

Abstract
Microcytotoxicity tests were used to study complement-dependent cytotoxicity of 2 monoclonal IgG2a antibodies, 96.5 and 118.1, both alone and in combination. These antibodies are specific for 2 antigenic determinants, p97a and p97b, respectively, of p97, a cell-surface glycoprotein present on most human melanomas and, in smaller amounts, on other tumors and normal tissues. For 10 of 12 melanoma lines, complement-dependent cytotoxicity was much greater in the presence of both antibodies than with either antibody alone. Synergism was not observed when the antibodies were tested in combination with an IgG2a antibody to a different cell-surface glycoprotein, nor was it detected in tests of 4 non-melanoma cell lines.
Suppression of antibody responses by cells from mice treated with picryl sulfonic acid: T cells that suppress IgG antibody without inhibiting concomitant IgE responses.
Authors: Thomas W R , Watkins M C , Cox K O , Asherson G L 
Published: December 2022

Abstract
T cells from mice injected with picryl sulfonic acid (PSA) can inhibit the anti-trinitrophenyl (TNP) antibody responses of mice produced after skin painting with picryl chloride (PCl). This had unusual specificity because the cells could inhibit IgG PFC responses in draining lymph nodes by 90% without affecting anti-TNP IgE responses as measured by heterologous adoptive cutaneous anaphylaxis. Although showing specificity for the class of antibody, the suppressors did inhibit IgG antibody responses to another sensitizer, oxazolone, although to a lesser degree. Responses to TNP-KLH, however, were unaffected.
Human lymphocytes can generate thymus-independent as well as thymus-dependent anti-hapten plaque-forming cell responses in vitro.
Authors: Golding B , Chang S P , Golding H , Jones R E , Pratt K L , Burger D R , Rittenberg M B 
Published: December 2022

Abstract
Human lymphocytes from peripheral blood, tonsils, and adenoids produced hapten-specific anti-TNP antibodies after in vitro stimulation with TNP-Ba. This antigen did not appear to behave as a polyclonal activator since TNP-Ba-stimulated cells lysed TNP-conjugated sheep erythrocytes (SRBC) but not unconjugated SRBC or DPPC-conjugated SRBC, whereas cells from PWM-stimulated cultures formed hemolytic plaques with both haptenated and unhaptenated targets. In addition, TNP-Ba generated PFC were inhibitable by soluble hapten (TNP-EACA or TNP-BSA). B cells depleted of T cells (less than 1% E-RFC cells) were able to respond to TNP-Ba but not to PWM or TNP-KLH. When varying ratios of T and B cells were added to cultures the TNP-Ba anti-TNP response was found to have a linear correlation with the number of B cells added (r = 0.987) and was maximal in the absence of added T cells. This was in contrast to the response to TNP-KLH, which required T cells at a particular T:B ratio for optimal induction of anti-TNP PFC. Thus, both T-dependent and T-independent anti-hapten responses could be elicited in human lymphoid cell cultures.
Antigenic changes produced by complex formation between thrombin and antithrombin-III.
Authors: McDuffie F C , Peterson J M , Clark G , Mann K G 
Published: December 2022

Abstract
Immunization of goats and mules with human thrombin resulted in an antiserum that reacted only weakly with the parent molecule, prothrombin. Some of the antibodies in this antiserum showed a greater affinity for thrombin complexed to its naturally occurring inhibitor, antithrombin-III, than for active thrombin. An antiserum against the human thrombin inhibitor, antithrombin-III, produced 2 precipitin lines against human serum but only 1 against plasma. The 2nd line in serum was shown to represent precipitation of a complex of thrombin with antithrombin-III. The neoantigens appearing in antithrombin-III after complex formation were also present in complexes prepared with purified clotting factor Xa and antithrombin-III. Since purified host (mule) thrombin was also capable of causing formation of the neoantigenic sites when complexed to human antithrombin-III, it seems likely that these determinants result from interaction in the host between the immunogens (either human thrombin or antithrombin) and the appropriate interacting host protein (mule antithrombin-III or thrombin, respectively). Studies by radioimmunoassay showed that the antibodies formed are not completely specific for the neoantigens since they also react to a lesser extent with the free proteins.
Correspondence between lectin-defined and surface antigen-defined cell subpopulations in the human thymus: its variation during ontogeny.
Authors: Richard Y , Boumsell L , Coppin H , Mishall Z , Lemerle J , Bernard A 
Published: December 2022

Abstract
In the thymus of children, congruent to 50% of cells are recognized both by peanut agglutinin and soybean agglutinin (PNA+, SBA+), congruent to 23% of cells are PNA-, SBA-, and 23% are PNA-, SBA+. This pattern of recognition was compared with the reactivity of these cells with monoclonal antibodies recognizing T cell differentiation antigens A 50 and a series (T3, T6, T8) that defines 3 discrete stages of T cell differentiation. Most PNA+, SBA+ display T6 and T8 but not T3 antigens; most PNA-, SBA+ display T3+ and A 50+ but not T6; and T3-, T6-, A 50- cells are PNA-, SBA-. Thus, there is a close correspondence between PNA+, SBA+ cells and the common (cortical) T3-, T6+ thymocytes; between PNA-, SBA+ cells and late (medullary) T3+, T6- thymocytes; and between PNA-, SBA- cells and early thymocytes. During ontogeny, although there are fewer PNA+ cells in the thymus, the proportion of T3+ cells, T6+ cells, and T3-, T6- cells showed no major modification as early as 16 wk.
Isolation of Epstein Barr-virus and studies of its neutralization by human IgG and complement.
Authors: Nemerow G R , Cooper N R 
Published: December 2022

Abstract
An isolation procedure for Epstein-Barr virus (EBV) that yields substantial quantities of purified infectious virus is described. The transforming strain of EBV was obtained from the marmoset lymphoma cell line B95-8 after stimulation with the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Purification was achieved by dextran density gradient ultracentrifugation in the presence of bacitracin, which was included to prevent viral aggregation. When assayed in cord blood leukocytes, isolated EBV stimulated DNA synthesis and induced the formation of colonies of transformed cells. The yield of infectious virus as determined by these assays was 13 to 29%. Electron microscopic (EM) examination of negatively stained virions revealed the presence of 115-nm spherical enveloped particles containing an internal 55-nm ring-shaped nucleoid. Interactions between 3H-thymidine labeled EBV, IgG and complement (C) were examined by rate zonal ultracentrifugation. High concentrations of immune IgG aggregated the virus whereas IgG together with C induced lysis as demonstrated by release of labeled EBV nucleic acid. EM studies of the IgG and C mixtures performed in parallel revealed accumulation of protein on the viral envelope, progressive separation of the envelope from the nucleocapsid, and disintegration of the nucleoid. Approximately 25-fold less IgG was required for neutralization than for viral aggregation. Although C did not enhance the IgG dependent neutralization, physiologic concentrations of C in normal nonimmune human serum also inactivated the virus.
Natural killer (NK) cell activity in the rat. I. Isolation and characterization of the effector cells.
Authors: Reynolds C W , Timonen T , Herberman R B 
Published: December 2022

Abstract
This study has demonstrated the presence of large granular lymphocytes (LGL) in the rat and implicated a central role for these cells in mediating natural killer (NK) cell activity in this species. The LGL frequency from various organs was shown to be: peripheral blood = lung greater than spleen greater than peritoneal exudate greater than lymph node. Little or no LGL were found in the thymus or bone marrow. This pattern was similar to the distribution of NK activity, except for the lungs, which had no detectable activity. These studies have also shown that discontinuous Percoll density gradients can be used to highly enrich or deplete LGL from both spleen and peripheral blood. Enriched LGL populations were shown to bind selectively to NK-susceptible target cells and to demonstrate very high NK cell cytolysis. Since human NK activity has also been found to be clearly associated with LGL, the present findings indicate that rats may provide a very useful animal model for detailed studies of the ontogeny, regulation, and in vivo relevance of NK cells.
Secretory component-dependent hepatic transport of IgA antibody-antigen complexes.
Authors: Socken D J , Simms E S , Nagy B R , Fisher M M , Underdown B J 
Published: December 2022

Abstract
The ability of the liver to transport antigen-antibody complexes containing polymeric IgA was tested in a model system using the isolated perfused rat liver and soluble complexes formed between trinitrophenylated (TNP) antigens and MOPC 315, a polymeric mouse IgA protein with anti-TNP activity. A double-label strategy (125I and 131I) was used to separately follow antigen and antibody during isolation and transport by the isolated perfused liver. Complexes formed in antigen excess and isolated by gel filtration were added to the perfusate. The quantity of antigen or antibody transported was determined by counting the radioactivity in collected bile fractions. TNP-human albumin (TNP-HSA) complexed to polymeric IgA antibody was transported from blood to bile while the same antigen complexed to IgG antibody was not. The transport of IgA-(TNP-HSA) complexes was inhibited by preincubation with human secretory component (SC), which indicated that transport of such complexes proceeds though an SC-dependent mechanism previously described for uncomplexed polymeric IgA antibody. Complexes (m.w. congruent to 970,000) of trinitrophenylated bovine thyroglobulin (TNP-TG) and polymeric IgA were transported less well than IgA-(TNP-HSA) complexes (m.w. less than or equal to 460,000), even though both types of complexes bound SC. The possibility that the poor transport of IgA-(TNP-TG) complexes reflected a size restriction on hepatic transport from blood to bile is discussed.
Biologic and molecular characterization of the IgG serum blocking factor (SBF-IgG) isolated from sera of patients with EBV-induced infectious mononucleosis.
Authors: Veltri R W , Kikta V A , Wainwright W H , Sprinkle P M 
Published: December 2022

Abstract
Our laboratory has previously reported the isolation of a serum blocking factor (SBF) from infectious mononucleosis (IM) patients. The SBF has been purified by a combination of Sephadex QAE-50 ion exchange and Sephadex G-200 molecular sieve chromatography. This material was found to be devoid of soluble immune complexes, and immunochemically and biochemically was characterized as IgG and, hence, termed SBF-IgG. The SBF-IgG was shown to significantly (alpha = 0.05) suppress antigen specific (Influenza A-1[H1N1]) in vitro lymphocyte stimulation (LS) as well as leukocyte migration-inhibition (LMI) reactivity. Also, the SBF-IgG significantly suppressed the in vitro.LS response to phytohemagglutinin. In addition, the SBF-IgG when bound to normal donor lymphocytes significantly reduced the high affinity E-rosette (HAR) reactivity at 29 degrees C. A purified T lymphocyte subpopulation of normal donor lymphocytes specifically bound SBF-IgG, and the latter could be r covered using glycine-HCI. It appears that SBF-IgG is a nonspecific antibody; it binds neither lymphokines nor specific antigen, but apparently elicits its in vitro vitro cell-mediated suppressive effect at the level of the T lymphocytes.
Control of latent allotype expression by rabbit splenocytes.
Authors: McCartney-Francis N , Mandy W J 
Published: December 2022

Abstract
Serologic and chemical studies have suggested that immunoglobulin structural genes are under nonallelic genetic control. The transient appearance of unexpected (i.e., latent) allotypes in serum further suggests that cellular control mechanisms may be operative. We report here the results of our efforts to induce the expression of latent allotypes by cultured rabbit splenocytes. The protein A plaque assay facilitated with various anti-allotypic antisera was used to enumerate allotype-specific plaque-forming cells. When splenocytes from a b4 b4 rabbit are cultured in the presence of anti-b4 alloantisera, the number of b4 PFC (i.e., nominal) is suppressed and the number of PFC expressing the latent allotype is increased. The specificity of the induced latent PFC is dependent upon the source and allotypic mosaic of the antiserum added to the cultures. Our results suggest that lymphocytes committed to latent allotypes are normally suppressed. Activation by the appropriate alloantiserum directed against the nominal allotype may relieve a cell-mediated suppressive mechanism.
The presence of platelet-activating factor (PAF) in normal human mixed saliva.
Authors: Cox C P , Wardlow M L , Jorgensen R , Farr R S 
Published: December 2022

Abstract
This report describes PAF activity in normal human mixed saliva from each of 24 randomly selected donors. The human salivary PAF (HS-PAF) was similar to rabbit basophil PAF (acetyl glyceryl ether phosphorylcholine or AGEPC) with respect to the following characteristics: 1. HS-PAF co-chromatographed with the standard rabbit basophil AGEPC and with synthetic AGEPC. 2. HS-PAF and AGEPC were unaffected by hirudin, indomethacin, and creatine phosphate/creatine phosphokinase, the respective inhibitors of platelet activation induced by thrombin, arachidonic acid, and ADP. 3. HS-PAF and AGEPC were inactivated by a 5-min incubation with ALF, the acid-labile factor in normal human serum that rapidly destroys AGEPC. 4. HS-PAF was demonstrated to be functionally similar to AGEPC by cross-desensitization experiments. In the absence of Ca++, HS-PAF and AGEPC cross-desensitized washed rabbit platelets to subsequent stimulation by either HS-PAF or AGEPC after recalcification. 5. HS-PAF was demonstrated to be structurally similar to AGEPC by several simple chemical tests for functional groups.
Specific reversal of cytolytic T cell-target cell functional binding is induced by free target cells.
Authors: Balk S P , Mescher M F 
Published: December 2022

Abstract
Reversal of specific cell-cell adhesions between allogeneic cytolytic T lymphocytes (CTL) and 51Cr-labeled target cells has been studied by using a functional assay for specific target cell binding. Functional adhesions between CTL and a tumor cell target, the P815 mastocytoma, were stable in suspension for greater than 5 hr. Addition of unlabeled target cells, however, resulted in rapid reversal of functional binding. This reversal appeared to be specific in that no reversal was induced by tumor cells of other H-2 types. Functional reversal of conjugates between CTL and labeled spleen cells syngeneic with P815 also occurred in the presence of unlabeled P815 cells or normal spleen cells of the appropriate H-2 type. The reversal by P815 was substantially more efficient than by normal spleen cells. Furthermore, normal spleen cells of the appropriate H-2 type did not induce reversal of CTL-P815 target conjugates. Purified plasma membranes from P815 cells did not specifically reverse functional binding of CTL to either P815 or normal spleen cell targets. These results demonstrate that functional CTL-target cell binding can be specifically reversed by interaction with free target cells. The rate of reversal appears to be dependent on the relative affinity of the CTL for the bound versus the free target cell. CTL may provide a useful system for studying reversal of specific cell-cell adhesions.
T cell recognition of Moloney sarcoma virus proteins. II. Phenotypes of the different lymphocyte subpopulations producing and responding to blastogenic factors and their relative frequencies during tumor regression.
Authors: Lee J C , Enjuanes L , Cicurel L , Ihle J N 
Published: December 2022

Abstract
The characteristics of the blastogenic response of splenic lymphocytes from MoLV/MSV immune mice was examined. Splenic lymphocytes from immune mice proliferate in vitro in response to the major virion envelope glycoprotein, gp70. Associated with this response is production of blastogenic factors that induce the proliferation of nylon wool-purified lymphocytes from either normal or immune mice. The phenotype of antigen-specific lymphocytes essential for the production of blastogenic factors was found to be Thy 1.2+, Lyt 1+, 2-. The induction of proliferation by blastogenic factors does not require the presence of antigen. Using splenic lymphocytes from either normal or immune mice, blastogenic factors predominantly induce the proliferation of a Thy 1.2-, Lyt 1-, 2- lymphocyte. As a consequence of responding to blastogenic factors, in vitro, approximately 50% of this lymphocyte population becomes Thy 1.2+, Lyt 1+ over a period of 3 days. The frequencies of lymphocytes producing and responding to blastogenic factors were found to show characteristic changes during the course of tumor growth and regression.
Actin content in lymphocytes: a proposed correlation with their recirculating properties.
Authors: Mely-Goubert B , Bellgrau D 
Published: December 2022

Abstract
The DNAase inhibition assay, which allows for the titration of monomeric and total actin content per cell, has been applied to various subpopulations of rat lymphocytes. We found that characteristic values are associated with functionally distinct subpopulations. Thus, thymus-dependent (T) lymphocytes have significantly higher monomeric and total actin per cell than bone marrow-derived (B) lymphocytes, irrespective of the separation procedure used (in vitro or in vivo). Moreover, these values appear to increase with the differentiation state of the cells within the T compartment (i.e., from thymus to lymph node to thoracic duct lymphocytes). The fact that the observed trends overlap the known in vivo recirculating abilities of the populations tested prompted us to discuss the possible involvement of intracellular actin in the control of the cell-surface deformability.
Regulation of T cell growth factor production: arrest of TCGF production after 18 hours in normal lectin-stimulated mouse spleen cell cultures.
Authors: Gullberg M , Ivars F , Coutinho A , Larsson E L 
Published: December 2022

Abstract
The detailed kinetics of TCGF accumulation in Con A-stimulated spleen cell cultures shows a maximum at 24 hr, with a subsequent decrease in activity. This decrease is not due to the appearance of inhibitory substances "masking" TCGF activity. Pulse experiments show that the rate of TCGF production falls sharply after 18 hr and is completely arrested after 24 hr of Con A stimulation. The arrest in TCGF production is the result neither of culture depletion in medium components nor of limiting accessory cell function or inactivation of the lectin, and it thus seem to be the result of inactivation of TCGF-producing T cells. This regulation is not the result of a TCGF-mediated feedback mechanism but rather of lectin-induced suppressive cells that appear in culture after 24 hr and turn off de novo production of TCGF in fresh cultures.
Activated T cells in the synovial fluid of arthritic patients. II. In vitro activation of the autologous blood lymphocytes.
Authors: Galili U , Rosenthal L , Klein E 
Published: December 2022

Abstract
Lymphocytes isolated from the synovial fluid of arthritic patients were shown to express characteristics of immunoactivated T cells, such as the formation of stable E rosettes and natural attachment to normal and malignant cells. During 5 days incubation in autologous serum, the synovial T cells reverted to resting state. If, however, the synovial serum was present in the culture, the activated state was maintained. The blood lymphocytes of these patients did not have the markers of activation. When blood lymphocytes were mixed in vitro with the autologous synovial T cells, a proportion of them acquired the capacity to form stable E rosettes and to express natural attachment. Synovial polymorphonuclear cells or synovial serum were without effect on the blood lymphocytes. This phenomenon may represent an in vivo mechanism for the perpetuation of the cellular immune reactivity in the joint cavity.
Immune responsiveness of HRS/J mice to syngeneic lymphoma cells.
Authors: Johnson D A , Meier H 
Published: December 2022

Abstract
HRS/J, hr/hr and hr/+ mice were evaluated for their ability to resist challenge with a syngeneic tumor, HTU, and for their ability to mount a protective immune response when immunized in vivo with inactivated HTU cells previous to challenge with viable tumors. The heterozygous (hr/+) mice responded more strongly than the homozygous (hr/hr) mice. This response was characterized by the presence of an enhanced ability of spleen cells from immunized mice to form blasts in vitro when incubated with purified murine leukemia viruses (MuLV). We conclude that the in vivo response of HRS/J mice against this tumor is directed, in part, against MuLV antigens expressed on the tumor cells and that the relatively weak response of hr/hr spleen cells to these antigens may be mechanistically linked to their tumor susceptibility.
Antigen-primed helper T cell function in CBA/N mice is radiosensitive.
Authors: Phillips N E , Campbell P A 
Published: December 2022

Abstract
CBA/N mice have an X-linked immunodeficiency that includes a deficient humoral response to sheep red blood cells (SRBC). In order to study the cellular mechanisms of this deficiency we have examined helper T cell function to SRBC in an adoptive transfer system by using 2 different sources of helper T cells. When thymocytes were used as the source of helper T cell precursors in an adoptive transfer system, CBA/N thymocytes were as effective as CBA/Ca thymocytes in inducing CBA/Ca bone marrow cells to develop into both direct and indirect anti-SRBC plaque-forming cells (PFC). However, when SRBC-primed, irradiated recipient mice were used as the source of helper T cells, primed and irradiated CBA/N recipients developed significantly fewer direct and indirect anti-SRBC PFC than similarly treated CBA/Ca recipients when reconstituted with CBA/Ca bone marrow cells and challenged with SRBC. This difference in radioresistant helper T cell function was also observed when primed, irradiated (CBA/N X DBA/2)F1 defective male and nondefective female mice were used as recipients of F1 female bone marrow cells and SRBC, confirming that this defect is a part of the X-linked CBA/N immunodeficiency. This deficiency in radioresistant helper T cell function in CBA/N mice does not appear to be due either to suppressor T cell function, or to a negative effect of the CBA/N environment on either B cell maturation, T cell-B cell cooperation, or helper T cell function. We conclude that antigen-primed helper T cell function in CBA/N mice is radiosensitive. Possible reasons for this are evaluated and discussed.