bluuebunny/crossref_metadata_2025_split huggingface dataset:
LY-2+ effectors cytotoxic for syngeneic tumor cells: generation by allogeneic stimulation and by supernatants from mixed leukocyte cultures.
Authors: Hurrell S M , Zarling J M 
Published: December 2022

Abstract
The present study was aimed at gaining insight into means by which stimulation of mouse spleen cells with allogeneic normal cells in mixed leukocyte cultures (MLC) can result in the generation of effector cells cytotoxic for syngeneic tumor or transformed cells. Stimulation of lymphocytes from BALB/c or C3H mice for 5 days with cells from mice of every allogeneic strain tested, in medium containing mouse serum and lacking xenogeneic serum, resulted in the activation of effectors cytotoxic for syngeneic cells transformed spontaneously or by SV40, polyoma or adenovirus. In each experiment, all of the syngeneic transformed cell lines, as well as clones derived from these lines, were lysed to the highest degree by effectors obtained from the same culture, and therefore stimulated with cells from the same allogeneic strain. Although the particular allogeneic sensitizing strain that induced the highest cytolytic activity varied between experiments, effectors obtained from the culture with the highest cell recovery always exhibited the greatest cytotoxicity against all the syngeneic transformed cells and clones. Lysis was mediated predominantly by Ly-2+ effectors; total lytic units of cytotoxicity recovered after treatment with monoclonal anti-Ly-2 antibody and complement (C) were reduced by 85 to 90% compared to cells treated with C alone. Lysis of syngeneic tumor cells by the allosensitized effectors in cytotoxicity assays was not inhibited by the addition of unlabeled "blocking" lymphocytes from the allogeneic strain used for sensitization. In addition, it was found that lymphocytes cultured without stimulating cells for 5 days in medium supplemented with supernatants from secondary MLC that are known to contain high levels of lymphokines, mediated high levels of cytotoxicity on all the transformed cells tested, but lacked detectable cytotoxic activity for syngeneic or allogeneic Con A blasts. The MLC supernatant-activated effectors that lyse the transformed cells are phenotypically CTL, because treatment with anti-Ly-2 and C reduced lytic activity by approximately 75%. Taken together, these findings suggest that the generation in MLC of Ly-2+ effector cells cytotoxic for syngeneic transformed cell lines might not be due, in some cases, to lymphocyte responses to particular alloantigens on the stimulating cells that are cross-reactive with "alien" histocompatibility antigens on transformed cells, but rather is due to effector cell activation by lymphokines produced during allogeneic stimulation.
Monoclonal antibodies directed against mouse macrophages in different stages of activation for tumor cytotoxicity.
Authors: Taniyama T , Tokunaga T 
Published: December 2022

Abstract
Three rat monoclonal antibodies against mouse peritoneal macrophages in different stages of activation were produced and characterized. One of these (AcM.1) bound to activated macrophages induced by pyran and Corynebacterium parvum, but not to resident and thioglycollate medium- (TGC) or proteose peptone- (PP) elicited macrophages. On the contrary, the antigen identified by MM9 monoclonal antibody was expressed only on resident and TGC- or PP-elicited macrophages. WE15 monoclonal antibody, on the other hand, reacted with all of the macrophages described above. In the assay for function, AcM.1 and WE15 monoclonal antibodies in the presence of complement (C) abolished the capacity of activated macrophages induced by pyran or C. parvum but not the capacity of killer T cells and natural killer (NK) cells to kill tumor target cells. On the other hand, MM9 and anti-Thy-1.2 monoclonal antibodies in the presence of C, as expected, did not affect the cytotoxicity of activated macrophages. However, none of the four monoclonal antibodies in the absence of C had any blocking effect on macrophage-mediated cytotoxicity. AcM.1 antibody reacted with two polypeptides with m.w. of 70,000 and 45,000 on pyran-activated macrophages; however, the antigens recognized by WE15 and MM9 have not been determined yet. These results indicate that the three rat monoclonal antibodies define different antigens present on macrophages at different stages of activation for tumor cytotoxicity, and that these antibodies should prove to be useful probes for analyzing the mechanism of activation of macrophages for tumor cytotoxicity.
Frequencies of alloreactive and self-restricted cytotoxic T cell precursors during lymphatic regeneration.
Authors: Buszello H , Pottmeyer C , Dröge W 
Published: December 2022

Abstract
The previous observation that during lymphatic regeneration precursors for MHC-restricted cytotoxic T cells appear before alloreactive precursors, was re-examined in macroculture and microculture experiments. Our macroculture experiments confirmed the observation that treatment with cyclophosphamide decreases the ratio of alloreactivity vs self-restricted reactivity. This shift in reactivity, however, did not result from a change in the T cell specificity repertoire, but was obviously mediated by regulatory effects in macrocultures. Spleen cells from cyclophosphamide-treated mice had normal ratios of CTL precursor frequencies for the three different specificities tested, but they contained a suppressive activity that inhibited the responses of normal spleen cells in macrocultures. Note Added: After submission of this paper we became aware of the paper of Sihvola and Hurme (J. Immunol. 130:1077, 1983) who also showed that although macrocultures from cyclophosphamide-treated mice were negative for the alloresponse, the same spleen cells showed only a approximately threefold decrease in CTL precursors when analyzed in limiting dilution cultures.
Single cell studies on hapten-specific B lymphocytes: differential cloning efficiency of cells of various sizes.
Authors: Pike B L , Vaux D L , Nossal G J 
Published: December 2022

Abstract
Three separate forms of in vitro stimulation were assessed for their capacity to activate hapten-gelatin fractionated, fluorescein- (Flu) specific murine splenic B lymphocytes. They were: a) Flu-polymerized flagellin (Flu-POL) acting on a single Flu-specific B cell in microculture in the absence of "filler" or feeder cells, but in the presence of T cell-derived B cell growth and differentiation factor(s) (BGDF); b) a mixture of mitogens, E. coli lipopolysaccharide (LPS) and dextran sulfate, acting on a single Flu-specific B cell in the absence of added BGDF; and c) Flu-POL plus BGDF acting on single Flu-specific B cells as in a but with thymus filler cells also present. System c was markedly superior in causing antibody formation, 15 to 22% of cells forming a clone of Flu-specific antibody-forming cells (AFC), in contrast to 6% for system b and 3 to 6% for system a. Each stimulus was applied to single cells that had been size fractionated into samples of increasing size by using the forward light-scattering parameter of the fluorescence-activated cell sorter. Surprisingly, the smaller sized fractions proliferated poorly in system a and contributed less than 10% of the antibody-forming potential of the total population. The smaller cells proliferated better in system b, but only 10 to 15% of proliferating clones generated Flu-specific AFC, whereas the larger cells contributed 86% of the total AFC response. Even in system c, only 6% of the small cells formed AFC clones compared with 41% of the larger cells. It thus appears that the smaller half of murine B lymphocytes is relatively resistant to activation into proliferation and differentiation by "T-independent" antigens; when activated by mitogens, they clone less efficiently than larger cells. Despite these limitations, system c could generate a total of up to four hapten-specific AFC for every B cell placed into culture, making it the most efficient system of specific antibody formation yet described.
Functional heterogeneity of memory B lymphocytes: in vivo analysis of TD-primed B cells responsive to secondary stimulation with TD and TI antigens.
Authors: Rennick D M , Morrow P R , Benjamini E 
Published: December 2022

Abstract
The functional heterogeneity of memory B cells induced by a single determinant, consisting of a decapeptide representing amino acid residues 103-112 of tobacco mosaic virus protein (TMVP), was analyzed. Decapeptide specific antibodies were elicited in mice adoptively transferred with TMVP-immune spleen cells when challenged with TMVP, decapeptide conjugated to succinylated human gamma-globulin (SHGG), or decapeptide conjugated to Brucella abortus (BA). Whereas secondary stimulation by either TMVP or decapeptide-SHGG was dependent on appropriately primed T cells, stimulation by decapeptide-BA was independent of conventional T cell help. Furthermore, memory B cells responsive to TMVP (TD), decapeptide-SHGG (TD), or decapeptide-BA (TI. 1 prototype) were shown to consist of overlapping populations because adoptive recipients of TMVP-primed cells challenged simultaneously with TD and TI decapeptide antigens did not result in a higher antibody response than that elicited by one of the TD antigens injected alone. However, decapeptide-BA consistently induced a smaller antidecapeptide response than either TMVP or decapeptide-SHGG. This suggested that only a fraction of the memory B cell population which was activated by the original priming antigen (thymus-dependent) was also responsive to secondary in vivo stimulation by the priming hapten conjugated to Brucella abortus. Detailed analyses of the antibodies induced in the recipients of TMVP-immune spleen cells after secondary challenge with either TMVP, decapeptide-SHGG, or decapeptide-BA failed to distinguish between the responsive memory B cells; the antidecapeptide antibodies induced by all three immunogens shared the same fine specificities and immunoglobulin isotype composition. These data are viewed as further evidence that subsets of TD-primed B cells, which may display differential sensitivity to cross-stimulation with TD and TI forms of the antigen, represent distinct stages of memory B cell maturation within a common B cell lineage. In support of this conclusion, we establish a developmental relationship between TI and/or TD responsive decapeptide memory B cell in the following communication.
Phenotypic and functional characterization of murine B lymphocyte precursors isolated from fetal and adult tissues.
Authors: Landreth K S , Kincade P W , Lee G , Medlock E S 
Published: December 2022

Abstract
Murine fetal liver and adult bone marrow cells identified by monoclonal 14.8 antibody were enriched on antibody-coated polystyrene petri dishes. Cell surface immunoglobulin (sig)-bearing cells were depleted before this enrichment procedure, and the resulting preparations of 14.8+, slg- cells were characterized as to morphology, immunoglobulin gene expression, and functional potential in vivo and in vitro. All cells with detectable mu chains of IgM in the cytoplasm (cmu) were found to be included in the 14.8+ population. The enriched cells did not contain significant numbers of committed granulocyte-macrophage progenitor cells or putative hemopoietic stem cells. Selected cells from 16-day fetal liver were large, a majority of the cells had a lobulated rather than a spherical nuclear outline, and less than 1% had detectable cmu. Enriched cells from 19-day fetal liver were on the average smaller than those from 16-day-gestation liver and had a more typical lymphoid morphology; 30% were cmu+. Adult bone marrow 14.8+, slg- cells were similar to 19-day fetal liver cells in morphology, and approximately half were cmu+. These selected precursor cells retained the capacity to mature in vivo and in vitro. Fetal and adult 14.8+, slg- cells were efficient in generating newly formed B cells in vivo, and this maturation step appeared to be dependent on the presence of microenvironmental accessory cells. However, the ability of positively selected cells to mature in vitro was markedly decreased, and this potential was not rescued by providing known sources of accessory cells. Possible reasons for this difference are considered. This technique for positively selecting cells has allowed us to directly compare for the first time B cell precursors from fetal and adult tissues and will be invaluable for resolution of the cell compartments in the differentiation of B lymphocyte precursors, in the study of accessory cells known to facilitate this process, in the definition of humoral factors which may act on pre-B cells, in the study of immunoglobulin gene rearrangements which take place during normal differentiation, and for further comparative studies of fetal and adult lymphopoiesis.
Accessory cell function of human endothelial cells. I. A subpopulation of Ia positive cells is required for antigen presentation.
Authors: Nunez G , Ball E J , Stastny P 
Published: December 2022

Abstract
The expression of class I and class II HLA antigens on preparations of human endothelial cells, isolated from umbilical cord veins, was investigated by immunofluorescence. While virtually all endothelial cells expressed class I antigens, less than 1% were positive for class II antigens, as detected with a panel of 10 different monoclonal antibodies. Antigen specific T cell lines proliferated in response to mumps antigen in the presence of endothelial cells or blood monocytes from HLA-DR matched donors. However, these T cell lines failed to respond in the absence of accessory cells or when accessory cells from HLA-D-region mismatched cord donors were used. The ability of both monocytes and endothelial cells to present antigen was abolished by treatment of the cells with monoclonal antibodies specific for either class I or class II HLA antigens plus complement. Similar treatment with monoclonal antibodies specific for monocytes greatly reduced antigen presentation by endothelial cells. These results indicate that preparations of endothelial cells contain a subpopulation of Ia positive cells, distinct from monocytes, which are required for antigen presentation.
The J744.2 cell line presents antigen in an I region restricted manner.
Authors: Schwarzbaum S , Diamond B 
Published: December 2022

Abstract
We report here the ability of a murine macrophage-like cell line, J774.2, to present antigen to primed T cells in a genetically restricted manner. J774.2 is a subclone derived from the reticulum cell sarcoma cell line, J774. Like mature macrophages, J774.2 possesses Fc receptors for all immunoglobulin G (IgG) subclasses; it is capable of performing Fc-mediated phagocytosis, and it secretes both lysozyme and plasminogen activator.
The human immune response to insulin. I. Kinetic and cellular aspects of lymphocyte proliferative responses in diabetics.
Authors: Nell L J , Thomas J W 
Published: December 2022

Abstract
A reproducible culture system was developed with the use of peripheral blood mononuclear cells (MNC) from insulin-dependent diabetic subjects to assay T cell proliferation in response to mammalian insulins. Kinetic analysis revealed that maximal responses occur after 8 to 10 days of culture with 50 to 100 micrograms of insulin. Characterization of the cells involved showed that two cell types are required for this proliferative response: a radioresistant non-T cell and an E rosette-forming (T) lymphocyte. With the use of this assay, 16 of 32 insulin-dependent diabetics had demonstrable MNC proliferation in response to insulin or to the control antigen, tetanus toxoid. Among those 16 subjects a spectrum of responsiveness to insulin was found. Because MNC from all responsive subjects react to both beef and pork insulin, it appears that shared determinants are recognized by insulin-immune lymphocytes in this outbred population. In addition, cells from one subject were found to respond in a determinant-specific manner to the A-chain loop of beef insulin. Reproducibility of the assay was demonstrated over an 8-mo period in three experiments with the use of MNC from a single subject. This reliable assay of T lymphocyte responses to a defined antigen will help determine the fine specificity and genetic regulation of the immune response to insulin in man.
Isolation and properties of a new short ragweed pollen allergen, Ra6.
Authors: Roebber M , Hussain R , Klapper D G , Marsh D G 
Published: December 2022

Abstract
Two chromatographic forms (A and B) of the rapidly released short ragweed (Ambrosia elatior) pollen allergen Ra6 were isolated to antigenic ultrapurity by a combination of membrane filtration and ion exchange and gel filtration chromatography. Both Ra6 forms had a m.w. of 11,500 by gel filtration chromatography and 8000 by SDS-PAGE, and each consisted of two cathodically migrating bands on agarose electrophoresis at pH 8.5. Amino-terminal amino acid sequencing analysis detected two similar sequences (sequence 1 and sequence 2), which were present in different proportions in each of the chromatographic forms of Ra6. Among a ragweed-positive population sample (n = 101), 21% had specific IgE antibody (ab) and 42% specific IgG ab toward Ra6A; among ragweed-negative subjects (n = 260), 10.8% had IgG ab. We were unable to discriminate between Ra6A and Ra6B immunologically with the use of hyperimmune animal antisera or IgE and IgG ab from five Ra6-allergic humans. It appears that Ra6 is composed of at least four closely related isoallergens of similar size but slightly different charges and amino acid sequences, which appeared to be antigenically and allergenically indistinguishable according to present evidence.
Inhibitory activity of antibodies to human Ia-like determinants: comparison of intact and pepsin-digested antibodies.
Authors: Muchmore A V , Megson M , Decker J M , Knudsen P , Mann D L , Broder S 
Published: December 2022

Abstract
Antibodies which react with products encoded by the human DR locus precipitate a biomolecular membrane glycoprotein complex with m.w. of 29,000 and 34,000 daltons. Such antibodies are directed against HLA-DR Ia-like antigens found on human B cells and human monocytes and have been shown previously to inhibit a variety of in vitro cellular and humoral immune reactions. We have compared the in vitro effects of such antibodies on two assays of human immunity: antigen-specific proliferation and polyclonal immunoglobulin production. Intact IgG fractions of a rabbit heteroantiserum (anti-P29,34), a human MT-2 locus alloantiserum (Ia 172), and a mouse monoclonal antibody (LB 3.1) markedly inhibited in vitro immune reactivities of human mononuclear cells. Interestingly, F(ab')2 preparations of these antibodies failed to inhibit these in vitro immune responses at the concentrations tested. These data suggest that under certain conditions, Fc domains play a critical role in the inhibitory activity of antibodies to Ia-like molecules.
Sequential expression of T cell activation (Tac) antigen and Ia determinants on circulating human T cells after immunization with tetanus toxoid.
Authors: Yachie A , Miyawaki T , Uwadana N , Ohzeki S , Taniguchi N 
Published: December 2022

Abstract
Recent studies have indicated that a monoclonal antibody, termed anti-Tac, may recognize the receptor sites or closely associated structures for interleukin 2 on activated human T cells. The Tac antigen, definable by anti-Tac antibody and usually found on mitogen- or alloantigen-stimulated T cells, was not expressed to any appreciable extent on normal circulating T cells. In the present study, we showed that an increase in circulating T cells expressing Tac antigen as well as Ia determinants occurred in normal individuals after immunization with tetanus toxoid. The expression of Tac antigen and Ia determinants on T cells was evaluated by the rosette method with Staphylococcal protein A-(SPA) coated bovine red blood cells (BRBC) or the indirect immunofluorescence method with monoclonal anti-Tac and anti-Ia antibodies. An increase in Tac-positive or Ia-positive T cells was more evident with the use of the rosette method with SPA-coated BRBC than with conventional immunofluorescence. The percentage of Ia-positive T cells showed a peak between 24 and 48 hr after toxoid injection, and remained at high levels until 2 wk after immunization. In contrast to Ia-positive T cells, the appearance of Tac-positive T cells was transient and at a rather early period of toxoid immunization. The maximum increase of Tac-positive T cells was apparent around 12 hr after toxoid injection, and Tac-positive T cells disappeared abruptly from circulation by 24 hr after inoculation. Ia-positive T cells were induced in both Leu-2 suppressor/cytotoxic and Leu-3 helper/inducer subsets, whereas Tac-positive T cells were generated only within the Leu-3 subset. The fact that induction of Tac-positive and Ia-positive T cells might occur at different stages of T cell activation and in different subsets of T cells seemed to be important for elucidating their roles in the in vivo T cell proliferation and differentiation.
Enhancement of susceptibility of HSV-1-infected cells to natural killer lysis by interferon.
Authors: Muñoz A , Carrasco L , Fresno M 
Published: December 2022

Abstract
The effect of interferon (IFN) on the natural killer (NK) activity of human PBL against HSV-1-infected HeLa cells was studied. Human PBL from several individuals did not consistently show a preferential lysis of HSV-1-, vaccinia-, or adenovirus type 5-infected cells with respect to uninfected HeLa cells. Treatment with IFN of effector PBL increased their lytic activity but did not alter the degree of preference on the lysis of the target cells shown by untreated PBL. Pretreatment with IFN of HSV-1-infected HeLa cells increased their susceptibility to lysis 5- to 10-fold. In contrast, identical pretreatment of the uninfected, adenovirus type 5- or vaccinia virus-infected HeLa cells before the assay decreased their susceptibility to NK lysis. This effect was not likely to be due to a block of the viral replication because other inhibitors like mitomycin C did not have the same effect. All target cells induced IFN synthesis in effector PBL cells. A similar level of IFN was induced by HSV-1-infected or uninfected HeLa cells. Pretreatment with IFN of HSV-1-infected, but not uninfected, HeLa cells induced 5 to 10 times more IFN by PBL, in good correlation with the increase in lytic activity. PBL treated with IFN, however, in conditions to give maximal stimulation of NK activity, presented the same preferential lysis of HSV-1-infected HeLa cells and synthesized similar levels of IFN as untreated PBL. In addition, HSV-1-infected HeLa cells were killed through different target structures than uninfected cells. Taken together, our results indicate an effect of IFN at the level of the NK target structures in HSV-1-infected HeLa cells by increasing either their number or, more likely, their affinity for NK cells independent of the effect of IFN in the effector cells or as an antiviral agent.