bluuebunny/crossref_metadata_2025_split huggingface dataset:
Membrane Proteins of the P388D1 Macrophage Cell Line: Isolation of Membrane Polypeptides That Bind to the Fc Portion of Aggregated IgG
Authors: D'Urso-Coward Maria , Cone Robert E. 
Published: December 2022

Abstract
Lactoperoxidase-catalyzed cell surface radioiodination was employed to radiolabel membrane polypeptides of a murine macrophage cell line P388D1. Optimal conditions for radioiodination of P388D1 cells were determined and were found to differ from conditions used to label lymphoid cells. SDS-polyacrylamide gel electrophoresis of detergent soluble membrane polypeptides revealed that 9 to 10 molecular species from 1 × 105 to 0.15 × 105 daltons were labeled. Radioiodinated, Triton X-100 extracted P388D1 membrane polypeptides were subjected to affinity chromatography on aggregated IgG:Sepharose columns. Elution of the bound polypeptides and analysis by SDS-polyacrylamide gel electrophoresis revealed polypeptides with an apparent molecular size of 8 × 104, which possess binding affinity for the Fc portion of aggregated IgG. The 8 × 104 dalton membrane polypeptides do not readily aggregate, are resistant to degradation, are not composed of disulfide-linked subunits, and do not appear to contain much carbohydrate. Cellular binding characteristics paraleled the binding of soluble receptor for sieved fractions of aggregated IgG suggesting that these polypeptides may be responsible for the in situ binding of aggregated IgG to P388D1 cells.
Types of Cells Involved in Antigen-Stimulated and Spontaneous Rosette Formation with Toxoplasma Gondii
Authors: Noel Masihi K. , Werner H. 
Published: December 2022

Abstract
Antigen-binding cells were identified by using rosette formation of Toxoplasma gondii and defined lymphoid populations under different experimental conditions. Treatment of immunized spleen cell suspensions with anti-Thy 1 serum plus complement inhibited 5 to 29% of the rosette-forming cells (RFC). Higher numbers of thymus-derived lymphocyte-RFC were obtained after incubation at 4°C and by the centrifugation method than by simple incubation at 20°C. RFC were also observed with thymocytes. Combined treatment with anti-Thy 1 serum plus complement and depletion of adherent cells indicated that the major proportion, 46 to 70%, of RFC were B cells. Spleenocytes of nu/nu mice formed similarly high numbers of rosettes. Spontaneous RFC were observed in nonimmunized mice with both spleen and thymus populations. Numbers of rosettes varied considerably depending on the method and the source of cell population used. Removal of adherent cells from spleen suspensions resulted in RFC reduction of 14 to 25% in immunized and 14 to 33% in nonimmunized animals. Pretreatment with anti-mouse immunoglobulin inhibited completely the spleen and spontaneous thymus RFC and partially the thymus RFC in immunized animals.
In Vitro Immune Response of Human Peripheral Lymphocytes
Authors: Ohara Junichi , Kishimoto Tadamitsu , Yamamura Yuichi 
Published: December 2022

Abstract
Stimulation of human peripheral blood lymphocytes (PBL) with pokeweed mitogen (PWM) induced consistent increases of intracellular levels of cyclic AMP and cyclic GMP within 15 min. Increases of cyclic AMP were observed in both B and T lymphocyte populations, but increase of cyclic GMP was observed only in the B lymphocyte population. The addition of anti-µ antibody to B cells abolished PWM-induced increase of cyclic GMP without any effect on cyclic AMP response. Anti-δ antibody did not show any inhibitory or stimulatory effect on PWM-induced increase of cyclic GMP or cyclic AMP. Pretreatment of B cells with anti-µ antibody at 37°C for 1 hr inhibited PWM-induced increase of cyclic GMP, whereas pretreatment with anti-µ antibody at 4°C did not show any inhibitory effect on PWM-induced increase of cyclic GMP. The effect of anti-µ-pretreatment was reversible and pretreated cells were recovered from the inhibitory effect of anti-µ antibody after 36 hr culture.
Regulation of Antibody Response in Different Immunoglobulin Classes
Authors: Kishimoto Tadamitsu , Hirai Yoshikatsu , Suemura Masaki , Nakanishi Kenji , Yamamura Yuichi 
Published: December 2022

Abstract
IgE class-specific suppressor factors (IgE-TsF) released from DNP-Myc-primed T cells showed their suppressor effect in an antigen nonspecific manner, although DNP-specific stimulation was required for their induction. The suppressor activity of IgE-TsF was absorbed with the alloantiserum directed to the subregions between I-A and I-E of the H-2 complex. IgE-TsF from BALB/c mice did not show their suppressor effect on the IgE response of C57BL/6J and vice versa. The suppressor activity of IgE-TsF was removed with a DNP-OA-primed B lymphocyte population including an increased number of IgE-B cells, but not with T cells. Incubation of hapten-primed B cells with IgE-TsF for 3 hr at 37°C selectively abolished the anti-hapten IgE antibody response in the adoptive transfer experiment, indicating that the target cells of IgE-TsF were IgE-B cells.
Regulation of the Immune Response to Tumor Antigen
Authors: Perry Linda L. , Benacerraf Baruj , Greene Mark I. 
Published: December 2022

Abstract
The nature and function of suppressor factor(s) elaborated by suppressor T cells in response to certain chemically induced tumors have been further defined. Thus, suppressor factor(s) specific for the S1509a methylcholanthrene-induced fibrosarcoma have been shown to bear determinants encoded by the I-J subregion of the murine MHC since suppressive activity is removed by passage of the factor through an immunoadsorbent composed of anti-I-Jk coupled to Sepharose. No loss of activity was observed after passage of factor through control columns composed of normal mouse globulin. Furthermore, activity could be recovered from the relevant immunoadsorbent by elution with high salt.
The administration of crude suppressor factor(s) to normal animals for 4 days resulted in the development of a population of suppressor cells that act in a manner analogous to the suppressor cell population used for production of factor. These factor-induced suppressor cells are T cells and exhibit an antigen specificity similar to that displayed by the tumor-induced suppressor cells. Thus, tumor-specific suppressor factor(s) bear I-J determinants and are capable of inducing the appearance of suppressor T cells in the nontumor-bearing host, which may then act in a specific manner to limit host responsiveness to tumor antigen.
The Effect of T Cell Growth Factor on the Generation of Cytolytic T Cells
Authors: Baker Paul E. , Gillis Steven , Ferm Mary M. , Smith Kendall A. 
Published: December 2022

Abstract
The development of cytotoxic effector cells through primary allogeneic mixed tumor-lymphocyte culture (MTLC) was found to be accompanied by the production of T cell growth factor (TCGF). Addition of supplemental TCGF to MTLC resulted in the generation of significantly greater quantities of effector cells, and these effector cells displayed augmented cytotoxic activity. The TCGF-induced effect could not be duplicated by the addition of fresh medium or a mitogenic concentration of concananvalin A. Although TCGF augmented the proliferation of antigen-nonreactive cells, antigen-reactive cells appeared to be preferentially stimulated by TCGF. Finally, it was shown that depletion of TCGF from MTLC resulted in an impairment of proliferation and differentiation of cytotoxic effector cells. These findings demonstrate that soluble factors are involved in the regulation of in vitro cell-mediated immune responses in an analogous manner to similar factors that have been shown to regulate humoral immune responses. Therefore, the forces affecting TCGF production may modulate the amplitude of a T cell-mediated cytolytic response.
Structural Studies on the Murine Ia Alloantigens
Authors: Cook Richard G. , Uhr Jonathan W. , Capra J. Donald , Vitetta Ellen S. 
Published: December 2022

Abstract
Murine splenocytes were radiolabeled with 3H- and 14C-amino acids; the Ia alloantigens encoded by the I-A and I-E/C subregions were isolated by immunoprecipitation and analyzed for structural variation by polyacrylamide gel electrophoresis. The I-A subregion products (k, d, and b haplotypes) are composed of two polypeptides, α and β, with m.w. of 34,000 and 26,000 daltons, respectively. Haplotype-associated differences in m.w. were detected in the I-E/C products of the k, r, p, and d haplotypes. The α and β chains of E/Ck and E/Cr are 34,000 and 28,000 daltons, respectively; E/Cp and E/Cd molecules are composed of 31,000 and 29,000 dalton polypeptides. Thus, there is both subregion (I-A vs I-E/C) and haplotype (E/Ck, E/Cr vs E/Cd, E/Cp) associated variation in the m.w. of the Ia alloantigens. Additionally, the covalent vs noncovalent association of the Ia subunits was examined and it was found that the α and β chains of both I-A and I-E/C are not covalently associated. However, the I-A α and β chains tend to associate through disulfide bonds during detergent lysis; the presence of alkylating agents during cell lysis prevents this association, and only free α and β chains are observed under nonreducing conditions.
Properties of H-2L Locus Products in Allogeneic and H-2 Restricted, Trinitrophenyl-Specific Cytotoxic Responses
Authors: Levy Robert B. , Shearer Gene M. , Hansen Ted H. 
Published: December 2022

Abstract
The role of the recently defined L antigen (a second D region product) in allogeneic and TNP-specific syngeneic primary CML responses has been investigated. The lysis by anti-L specific cytotoxic effector cells was not inhibited when the target cells were pretreated with an antiserum directed against K and D, whereas an antiserum against L completely abrogated this response. Therefore, H-2L products are recognized on the target cells independently of H-2K and H-2D locus products. Both A.SW cells as well as B10 cells were found to respond to Ld alloantigens, in addition to Dd alloantigens when stimulated by cells differing only in the D region. The results of cold target blocking and antiserum inhibition experiments failed to detect cytotoxic cells with specificity for L antigens in association with TNP, under conditions in which TNP-specific effectors to K and D antigens were demonstrable. These findings suggest that there is a more limited involvement of H-2L locus products than the H-2K or H-2D locus products in the induction and specificity of these responses.
5′-Nucleotidase Activity in Subpopulations of Rat Lymphocytes
Authors: Barton Randall W. , Goldschneider Irving 
Published: December 2022

Abstract
Rat lymphocyte populations were assessed for 5′-nucleotidase activity by both biochemical and histochemical methods. Enzyme-specific activity was enriched in lymphocyte plasma membrane fractions and was higher in lymph node and spleen lymphocytes than in thymocytes. Histochemical reactions on sections of spleen and lymph node revealed strong activity in the thymus-dependent regions, periarteriolar lymphoid sheath in spleen, and paracortes in lymph node; whereas the thymus-independent regions, follicles, and germinal centers were negative. In cellular depletion experiments, with three different methods to detect 5′-nucleotidase, it was observed that the depletion of T cells, but not B cells, was accompanied by a loss of enzyme activity and a decrease in the percentage of nucleotidase-positive cells. The results suggest that, among members of the lymphocyte series, high 5′-nucleotidase activity is selectively associated with the plasma membranes of peripheral T cells in the rat.
Modulation of Immune Response by Bacterial Lipopolysaccharide (LPS): Cellular Basis of Stimulatory and Inhibitory Effects of LPS on the in Vitro IgM Antibody Response to a T-Dependent Antigen
Authors: Uchiyama Takehiko , Jacobs Diane M. 
Published: December 2022

Abstract
The role of thymus-derived lymphocytes (T cells) in LPS modulation of T cell-dependent antibody responses has been investigated. We have assessed the effect of LPS on the primary anti-TNP response to TNP-SRBC of cultures of whole spleen cells or T cell-depleted spleen cells that were supplemented with various subpopulations of carrier-primed (SRBC) spleen cells. The TNP-PFC response was enhanced in the presence of irradiated SRBC-primed spleen cells by addition of 0.16 to 20 µg/ml LPS, but inhibition was observed when irradiation of primed cells was omitted. Enhancement but no inhibition occurred when added primed cells were first passed through a nylon wool column. LPS-mediated enhancement was dependent on a T cell in the primed population. These results suggest that LPS modulation of antibody synthesis is dependent on two populations of antigen-specific cells that have opposing effects on B cell responses to a T-dependent antigen: a helper cell that is irradiation resistant, nonadherent to nylon wool, and sensitive to anti-T cell serum, and a suppressor cell that is irradiation sensitive and adherent to nylon wool.
Regulation of the Immune Response to Tumor Antigen
Authors: Greene Mark I. , Perry Linda L. 
Published: December 2022

Abstract
Suppressor T cells arising during the development of certain murine methylcholanthrene-induced fibrosarcomas have previously been shown capable of limiting only those effector responses generated against the homologous tumor. Thus, S1509a-induced suppressor T cells inhibit immune reactivity only to the S1509a tumor in S1509a immune mice and have no effect on the rejection of SAI tumors in SAI-immune animals. In contrast to this is the cross-reactivity of effector cells in this system, whereby animals rendered immune to either the S1509a or SAI sarcoma are equally capable of rejecting a challenge of the opposite tumor. The specificity of suppression has been further defined in the present study, which demonstrates that S1509a-induced suppressor cells can inhibit responsiveness only to the S1509a sarcoma, even in the simultaneous presence of both the S1509a and SAI tumors. Furthermore, the suppressor factor that is obtainable from suppressor T cells demonstrates a similar precise specificity in its ability to limit selectively reactivity only against the inducing tumor, regardless of the simultaneous expression of antigens on other tumors recognized by cross-reactive effector cells. These results suggest that the antigenic determinants recognized by effector and suppressor T cells are different, and may provide a model for further dissection of suppressor cell function in vivo.
Expression of I-A and I-E,C Region-Coded Ia Antigens on Functional B Cell Subpopulations
Authors: Frelinger Jeffrey A. , Hibbler Frederic J. , Hill Sharon W. 
Published: December 2022

Abstract
Ia antigens from specific subregions have been examined on functional B cell populations. Expression of both I-A and I-E,C region antigens was demonstrated on cells required for both lipopolysaccharide mitogenesis and polyclonal activation. Similar I-A and I-E,C subregion expression was found on cells required for response to the T-independent antigen, polyvinylpyrrolidone. TNP-specific IgM and hen egg lysozyme-specific IgG plaque-forming cells also express I-A and I-E,C region antigens. No evidence was found for an Ia- population responsive in the systems tested. Further, no evidence of preferential expression of I-A or I-E,C region antigens was observed in any system examined. Therefore, it appears that B cells express both I-A and I-E,C region-coded Ia antigens.
The Mouse Mutant “Motheaten”
Authors: Sidman Charles L. , Shultz Leonard D. , Unanue Emil R. 
Published: December 2022

Abstract
The developmental status of B and T lymphocytes was examined in the mouse mutant “Motheaten”. At all ages, these mice have reduced levels of B cells but similar levels of T cells, as compared to control littermates. Motheaten mice do not develop the mature forms of B cells that appear in control mice at about 3 weeks of age. Instead, B cells from motheaten mice are characterized by a paucity of surface IgD and complement receptors, defective capping behavior of surface Ig, and a decrease in the low-to-intermediate peak of fluorescence intensities seen with a fluorescence-activated cell sorter. Unlike immature B cells from normal mice, immature B cells from motheaten mice are not inactivated by anti-Ig interactions in vitro. However, this may be due to an enhanced in vitro development of new Ig-positive cells. Finally, in vivo, motheaten mice show a spontaneous differentiation of B lymphocytes to Ig-secreting plasma cells, starting at about 3 weeks of age. Our current hypothesis is that the block in B cell development seen in motheaten mice may be apparent rather than real and instead may reflect an overall enhancement of the B cell developmental pathway. The lack of mature-type B cells in motheaten mice is thought to be due to a nonspecific influence driving them to the Ig-secreting plasma cell stage as soon as they are formed.
µ-Chains from a Nonsecretor B Cell Line Differ from Secreted µ-Chains at the C-Terminal End
Authors: Williams P. Brock , Kubo Ralph T. , Grey Howard M. 
Published: December 2022

Abstract
Peptide analysis and carboxypeptidase-A digestion have been applied to compare the C-terminal primary structure of µ-chains from nonsecreting and secreting human B cell lines. The expected release of C-terminal tyrosine was seen with internally labeled secreted µ-chains; however, only a small amount of tyrosine was released from internally labeled nonsecreted µ-chains. The greater quantity released of other hydrophobic amino acids Phe, Val, and Leu, together with differences in the kinetics of release suggested that tyrosine was not the C-terminal residue. Since these other amino acids are not found near the C-terminal sequence of secreted µ-chains (-Ser-Asp-Thr-Ala-Gly-Thr-Cys-Tyr-COOH), these results indicate a structural difference between these two forms of µ-chains. Further evidence of a structural difference between these two forms of µ-chains was obtained by the analysis of cyanogen bromide peptides. The C-terminal octapeptide from myeloma and secreted internally labeled µ-chains could be isolated by Sephadex G-50 chromatography and high voltage electrophoresis. In contrast, no such peptide could be obtained from nonsecreted internally labeled µ-chains. These results also strongly indicate that nonsecreted µ-chains (i.e., membrane) possess a different C-terminal structure from those that are secreted. These data have led to the proposal of a hydrophobic C-terminal trailer sequence being responsible for the affinity of nonsecreted µ-chain for the plasma membrane.
B Lymphocyte Expression of a Recognition Locus for Human Monocytes and Macrophages
Authors: Guerry Dupont , Dusak Betsy A. , Schreiber Alan D. , Cooper Richard A. 
Published: December 2022

Abstract
Monocyte and macrophage interactions with other cell types are critical to certain immune responses. Such interactions usually require close physical contact between mononuclear phagocyte and target cell. We have explored the recognition (binding) of cultured human proliferative B lymphocytes by monocytes and macrophages. These studies demonstrate that monocytes have the capacity to recognize a variety of B lymphoblast and lymphoblastoid cell lines. This capacity is enhanced by the generation of macrophages in culture but does not extend to the PMN. Binding does not occur at 4°C and depends on the presence of either Ca or Mg ions. Normal peripheral blood lymphocytes, the B cells of chronic lymphocytic leukemia, mitogen-transformed T cells, and three T lymphoblast cell lines are not bound by monocytes. Recognition does not require identity at the histocompatibility locus, proceeding in allotypic as well as autologous situations. The recognition locus of proliferating B cells is trypsin sensitive and regenerable with incubation in the absence of serum. Regeneration of this structure is blocked by the protein synthetic inhibitor cycloheximide. B cell interaction with monocytes is not mediated by immunoglobulin G, by exogenously derived complement (C) or C3b or C3d from any source, by heterologous bovine antigens, by Epstein-Barr virus-determined antigens, or by currently defined, B cell-specific, cell-surface determinants. This locus may provide one means of initiating cell-cell interactions important in the host response to viral induced or neoplastic proliferation of B lymphocytes.
Immune Response to a Mammary Adenocarcinoma
Authors: Huber S. A. , Lucas Z. J. 
Published: December 2022

Abstract
Serum from Fischer rats immunized with 107 cytolytic spleen cells from syngeneic rats bearing the 13762A mammary adenocarcinoma inhibits specific cell-mediated cytotoxicity (CMC). The blocking activity is first detected 5 to 7 days after immunization; peak activity is reached 5 days later. Immunization with spleen cells depleted of T lymphocytes by heterologous anti-T lymphocyte serum and complement abrogates the blocking response. The blocking factor specifically inhibits lysis of the mammary tumor; it does not inhibit lysis of a Maloney sarcoma virus-induced tumor cells (MSVT) or allogeneic fibroblasts by specifically immune spleen cells. Sephacryl S-200 chromatography and immunoadsorption to rabbit anti-rat IgG or anti-rat µ-chain columns indicate that 10 days after immunization, 30% of the blocking activity is IgM and 70% is IgG.
The IgG-blocking activities from animals bearing the 13762A tumor and from animals immunized with lymphocytes from tumor-bearing animals have identical inhibitory specificities. Ascites tumor inocula contained up to 14% host lymphocytes. Depletion of T lymphocytes from the inocula abrogate the early appearance of IgG-blocking activities and prolong animal survival. We interpret these results to suggest that the IgG-BF in sera from 13762A mammary tumor-bearing rats is induced by a small number of immune T cells contaminating the ascites tumor inoculum. It is considered likely, but remains unproven, that anti-receptor antibody-like blocking factors also occur in spontaneously arising tumors.
Adherent Cell Function in Murine T Lymphocyte Antigen Recognition
Authors: Rosenwasser Lanny J. , Rosenthal Alan S. 
Published: December 2022

Abstract
The mechanisms by which adherent cells, presumably of mononuclear phagocytic lineage, influence in vitro antigen-specific activation of murine T lymphocytes was examined. Two distinct functions for macrophages could be discerned. One macrophage function is dependent on a soluble factor produced by cultured adherent cells and is most easily studied with complex multideterminant antigens. This factor is neither antigen-specific nor MHC-restricted in its action in that PEC, regardless of haplotype, produce factor in the absence of antigen. A second function, antigen-specific T cell activation, is seen when antigens of more restricted heterogeneity are used, such as those under the control of Ir genes. This latter activity demands identity or partial identity between the antigen-presenting cell and the primed T cell, thus suggesting an additional specific, genetically restricted function for macrophages in in vitro antigen recognition. Whether these adherent cell functions are mediated by all or distinct subsets of cells was not established.