bluuebunny/crossref_metadata_2025_split huggingface dataset:
A predominant idiotype on rabbit anti-VH a1 allotype antibodies: sharing by both major and minor VH subgroups.
Authors: Metzger D W , Roux K H 
Published: December 2022

Abstract
In every rabbit examined, greater than or equal to 80% of antibodies directed against the VH allotypic marker, a1, bears a predominant idiotype (IdX-a1). The IdX-a1 marker is site-associated and expressed on H chains, but not L chains, of anti-a1 antibody. Experiments using rabbits suppressed for the VH a subgroup demonstrated that IdX-a1 can be associated with both major (a+) and minor (a-) VH subgroup gene products and that a1 rabbits contain IdX-a1 within their genetic repertoire. The genetic and regulatory implications of our results are discussed.
Human alveolar macrophages: potentiation of their tumoricidal activity by liposome-encapsulated muramyl dipeptide.
Authors: Sone S , Tsubura E 
Published: December 2022

Abstract
Homogeneous preparations of human alveolar macrophages (AM) were obtained by bronchoalveolar lavage of the lungs of healthy nonsmokers. These AM exhibited a low level of spontaneous cytolytic activity against allogeneic A375 melanoma cells. Tumoricidal activity of AM could be generated and/or augmented by incubation in vitro with either lipopolysaccharides (LPS) or muramyl dipeptide (MDP). MDP derivatives were encapsulated within multilamellar (MLV) liposomes composed of phosphatidylcholine-phosphatidylserine (PC/PS). Dose-response experiments established that liposome-encapsulated MDP augmented the tumoricidal activity of AM at concentrations about 100 times lower than free MDP in the medium. AM activated by MLV containing MDP destroyed allogeneic tumor cell lines, but did not affect cultures of normal, non-neoplastic cells. An inactive derivative, MDP-L, encapsulated in MLV liposomes did not potentiate the tumoricidal activity of AM. We conclude that human AM respond to MDP in vitro and that liposomes containing MDP are far more efficient than unencapsulated, free MDP for enhancing the tumoricidal activity of human AM.
Antibodies from the Lyb-5- B cell subset predominate in the secondary IgG response to phosphocholine.
Authors: Wicker L S , Guelde G , Scher I , Kenny J J 
Published: December 2022

Abstract
The X-linked CBA/N immune defect was used to investigate the role of the Lyb-5- B cell subset in phosphocholine- (PC) specific memory responses. Immune-defective mice, which express only the Lyb-5- B cell subset, are unable to mount a primary or secondary T15+, IgM response to PC but can produce a substantial secondary IgG response. The majority of these IgG anti-PC antibodies are T15- and can be inhibited by phenylphosphocholine, but not PC. Normal mice, which possess Lyb-5+ and Lyb-5- B cells, produce both IgM and IgG anti-PC antibodies; however, there is a striking difference in the idiotype and fine specificity of antibodies expressed by these two classes. The IgM anti-PC antibodies are T15+ and PC-inhibitable, whereas the IgG antibodies are identical to those observed in the immune-defective mice, i.e., T15- and PC-noninhibitable. This unexpected difference in both idiotype and fine specificity between IgM and IgG anti-PC antibodies results from activation of different B cell subsets. Lyb-5+ B cells produce T15+, PC-inhibitable IgM antibodies, whereas T15-, PC-noninhibitable IgG antibodies are produced by Lyb-5- B cells. These data indicate that a majority of the thymus-dependent, anti-PC IgG memory responses arises from Lyb-5- B cells.
The specificity of the syngeneic mixed leukocyte response, a primary anti-I region T cell proliferative response, is determined intrathymically.
Authors: Glimcher L H , Schwartz R H , Longo D L , Singer A 
Published: December 2022

Abstract
In previous studies, the syngeneic MLR of peripheral T cells was shown to be predominantly an I region-restricted function. In this report we show that adult thymocytes are also capable of responding to syngeneic irradiated stimulator cells in a syngeneic MLR, provided that TCGF is added to the culture system. Using this assay, it was possible for the first time to examine the pattern of I region restriction within the thymus itself. Analysis of the thymocyte syngeneic MLR in thymuses from radiation-induced bone marrow chimeras demonstrated that the MHC preference seen in the peripheral T cell population also existed in cells resident within the thymus. Experiments utilizing congenitally athymic mice transplanted with allogeneic thymic grafts demonstrated that both peripheral T cells and thymocytes from such animals displayed a strong preferential proliferation toward stimulator cells bearing thymic-type MHC determinants. The results in the nude model thus demonstrate that the thymus by itself is sufficient to impart such restriction specificity on a developing T cell repertoire. These results are consistent with the notion that the thymus exerts selective pressure on maturing T cell populations that results in a skewing of the T cell repertoire toward the recognition of thymic-type I region products, and that this MHC preference exists before expansion of T cells in the periphery.
Detection of IgG bound within human trophoblast.
Authors: Wood G W , Bjerrum K , Johnson B 
Published: December 2022

Abstract
Previous studies have failed consistently to detect either binding sites for exogenous IgG or endogenous IgG on human trophoblast by using conventional immunohistologic methods. The present study demonstrates specific binding sites for exogenous IgG on all trophoblast-derived cells. The binding sites were detectable with monomeric IgG but not IgG aggregates. The binding sites were detected more easily if cells were washed at an acid pH (5.0). The level of binding activity was greater in younger placental tissue, although expression of binding sites on cells in extraplacental membranes was age-independent. Complexing of bound exogenous IgG resulted in its dissociation from tissue binding sites. Endogenous trophoblast-associated IgG was readily detectable when anti-IgG reagents that produced minimal complexing were used, e.g., Fab fragments of rabbit antihuman IgG. High levels of both Fc gamma binding sites and endogenous IgG were detected in placentae as late as 30 wk gestation, but both were present only in low levels at term. The results demonstrate that both binding sites for exogenous and endogenous IgG are associated with the human trophoblast and support the theory that IgG transport through the human trophoblast is dependent on Fc gamma receptors.
Characterization of alloimmune memory in a sponge.
Authors: Bigger C H , Jokiel P L , Hildemann W H , Johnston I S 
Published: December 2022

Abstract
Alloimmune memory, revealed by consistently accelerated second-set graft rejection in contrast to unrelated third-party reactions, has been reported in four species of marine sponge. Allogeneic tissue of the marine sponge, Callyspongia diffusa was grafted/parabiosed to examine critically the essential features of alloimmune memory in this member of the least complex major metazoan phylum. Although sponges lack an organized circulatory system, the immunologic memory spreads rapidly through body tissues. Heightened reactivity persisted for only 3 yo 4 wk after primary sensitization. This appears to constitute a major difference from the long-term alloimmune memory found among vertebrates. This limited duration of memory, however, is apparently sufficient for the individual sponge to cope with repeated challenges to its integrity.
Specific binding of leukotriene B4 to receptors on human polymorphonuclear leukocytes.
Authors: Goldman D W , Goetzl E J 
Published: December 2022

Abstract
Leukotriene B4 (5(S),12(R)-di-hydroxy-eicosa-6,14-cis-8,10-trans-tetraenoic acid [LTB4]) is a product of the 5-lipoxygenation of arachidonic acid, which elicits human PMN leukocyte chemotactic responses in vitro that are 50% of the maximal level at concentrations of 3 X 10(-9) M to 10(-8) M and are maximal at 2 X 10(-8) M to 10(-7) M. The specific binding of highly purified [3H]LTB4 to human PMN leukocytes was assessed both by extracting the unbound and weakly bound [3H]LTB4 with acetone at -78 degrees C and by centrifuging the PMN leukocytes through cushions of phthalate oil to separate the unbound from bound [3H]LTB4. The levels of total binding of [3H]LTB4 and of nonspecific binding of [3H]LTB4, in the presence of a 1500-fold molar excess of nonradioactive LTB4, were approximately two times higher with the phthalate oil method. Scatchard plots of the concentration dependence of the specific binding (total - nonspecific binding) of [3H]LTB4 to PMN leukocytes were linear for the acetone extraction and phthalate oil methods and revealed dissociation constants of 10.8 X 10(-9) M and 13.9 X 10(-9) M, respectively, and mean of 2.6 X 10(4) and 4.0 X 10(4) receptors per PMN leukocyte. The 5(S),12(S)-all-trans-di-HETE analog of LTB4 and 5-HETE competitively inhibited by 50% the binding of [3H]LTB4 to PMN leukocytes at respective concentrations that evoked half-maximal chemotactic responses, whereas neither N-formyl-methionyl-leucyl-phenylalanine nor chemotactic fragments of C5 inhibited the binding. Human erythrocytes exhibited no specific binding sites for [3H]LTB4. Human PMN leukocytes possess a subset of receptors for LTB4 that are distinct from those specific for peptide chemotactic factors.
Opsonization of encapsulated Staphylococcus aureus: the role of specific antibody and complement.
Authors: Verbrugh H A , Peterson P K , Nguyen B Y , Sisson S P , Kim Y 
Published: December 2022

Abstract
Previous studies of encapsulated Staphylococcus aureus have shown that the opsonins of normal, nonimmune human serum (complement factor C3 and IgG) bind beneath the capsule, i.e., on the cell wall, and when bound at this site these opsonins are not effective in promoting phagocytosis of the bacteria by polymorphonuclear leukocytes (PMN). In this investigation immune antibody was added to human serum to effect opsonization of encapsulated S. aureus. Opsonization was assessed by quantitating the uptake of 3H-labeled staphylococci by human PMN, and the amount of C3 fixation to bacteria was measured in a quantitative fluorescent immunoassay. Low levels of immune antibody (IgG) effectively opsonized encapsulated S. aureus when added to fresh but not to heated serum; phagocytosis of the staphylococci was mediated via pronase-sensitive membrane receptors (presumably C3b receptors) of PMN. Experiments with C2-, C3-, or C5-deficient human sera revealed that C3 was required for opsonization and that activation of C3 was mediated via the alternative complement pathway. Encapsulated S. aureus bound significantly less C3 than unencapsulated strains in diluted normal serum; addition of immune antibody, however, increased C3 fixation 4.7-fold (p less than 0.005). Immunoelectron microscopy localized C3 throughout the capsule as well as on the staphylococcal cell wall when bacteria had been opsonized in human serum with immune antibody. Without immune antibody, C3 binding was restricted to the cell wall. At approximately 10-fold higher levels of immune antibody, opsonization and phagocytosis of encapsulated S. aureus was independent of complement and pronase-sensitive receptors on PMN. These studies show that, in addition to immune antibody, the alternative pathway of complement plays an important role in the opsonization of encapsulated S. aureus strains and suggest that complement may be crucial to the in vivo clearance of these organisms.
Helper cell function of Leukemic Leu-2a+, histamine receptor+, T gamma lymphocytes.
Authors: Siegal F P , Rambotti P , Siegal M , Lopez C , Smith M , Davies T F , Osband M , Estren S 
Published: December 2022

Abstract
Leukemic cells from a patient with an 11-yr history of chronic lymphocytic leukemia (CLL) were found to have the surface phenotype Leu-1+, Leu-2a+, Leu-3a-, sheep erythrocyte rosette+, IgGFc receptor+. The cells also bore a receptor for histamine inhibitable by cimetidine (H-2). The clonal nature of the proliferation was documented by the presence of a consistent marker chromosome (22-trisomy) in metaphases elicited by culture with T cell growth factors. Although the surface phenotype suggested that these cells might function as suppressor lymphocytes, they had an enhancing effect on the pokeweed- mitogen- (PWM) driven generation of plasma cells and reverse hemolytic plaque-forming cells in vitro. This helper activity was modified neither by irradiation of the leukemic cells nor by removal of a minor population of Leu-3a+ cells, suggesting that the effects were attributable to the CLL cells themselves. In addition to these functions, the CLL cells were active in antibody-dependent cellular cytotoxicity (ADCC) assays in association with expression of Fc receptors for IgG. The ADCC was diminished when a transient loss of the Fc receptor expression was observed. No activity in natural killer cell assays employing K-562 cells or herpes simplex virus- (HSV) infected cells as targets could be attributed to the leukemic clone. These studies indicate that the cell surface phenotype, as defined by monoclonal antibodies, may not always predict the functional state of a particular cell, and suggest that within the Leu-2a+ (TH-2+) population of human lymphocytes, some helper as well as suppressor/cytotoxic cells are to be found.
Effect of cyclosporin A on T cell function in vitro: the mechanism of suppression of T cell proliferation depends on the nature of the T cell stimulus as well as the differentiation state of the responding T cell.
Authors: Dos Reis G A , Shevach E M 
Published: December 2022

Abstract
We have studied the effects of the immunosuppressive agent cyclosporin A (CY A) on T cell activation in the guinea pig both in the presence and in the absence of exogenous interleukin 2 (IL 2). CY A suppressed T cell activation by the mitogen, concanavalin A, by blocking IL 2 production and not by blocking the induction of IL 2 receptors. In contrast, the primary T cell proliferative responses to self-Ia antigens in the syngeneic mixed leukocyte reaction (SMLR) and to trinitrophenyl-modified syngeneic macrophages were blocked by CY A and this suppressive effect could not be corrected by addition of exogenous IL 2. T cells primed to syngeneic stimulator cells in the presence of CY A failed to develop IL 2 responsiveness even in the presence of exogenous IL 2, suggesting that CY A directly blocked induction of IL 2 receptors on the responding T cell population. In contrast, the secondary SMLR was suppressed by CY A in the absence of IL 2, but was normal when IL 2 was added to the cultures. CY A completely blocked the primary allogeneic MLR but this inhibitory effect could be reversed when exogenous IL 2 was added to the cultures. Moreover, in the presence of exogenous IL 2, CY A had no effect on the development of IL 2 responsiveness by alloreactive T cells. In addition, CY A induced a population of radiosensitive cells with suppressor activity for the primary MLR. Thus, in the guinea pig, CY A inhibits Ti cell activation both by blocking IL 2 production as well as by inhibiting the induction of IL 2 responsiveness. These two effects occur in the same range of CY A concentrations and are differentially dominant depending on the nature of the stimulating signal and the differentiation state of the responding T cell.
Immune serum transfer of cutaneous basophil-associated resistance to ticks: mediation by 7SIgG1 antibodies.
Authors: Brown S J , Graziano F M , Askenase P W 
Published: December 2022

Abstract
Guinea pigs acquired resistance to Amblyomma americanum larval ticks after one infestation, resulting in 46% tick rejection when challenged. Intravenous transfer of immune serum from twice-infested hosts to naive animals conferred a significant level of immunity resulting in 18 to 30% tick rejection. The minimum effective dose of serum was 3 ml per recipient, and heating the serum at 56 degrees C for 4 hr had no effect on serum activity. Fractionation of whole immune serum by gel filtration chromatography (Sephadex G-200) and ion -exchange chromatography (DEAE) demonstrated resistance activity to be in the IgG- and IgG1-containing fractions, respectively. Passage of whole immune serum through a heavy chain-specific rabbit anti-guinea pig IgG1 affinity column removed anti-tick activity and decreased the cutaneous basophil response to tick feeding by 70% in recipients. The ability to transfer both resistance to tick feeding and a significant cutaneous basophil response was eluted from the affinity column with 0.2 M Na2CO3, pH 11.5. In addition, immune serum raised against larval Ixodes dammini ticks, but not larval Rhipicephalus sanguineus ticks, was also effective at reducing feeding by larval Amblyomma americanum ticks, indicating that antibodies mediating resistance can be cross-reactive with antigens of different tick species and genera. This study demonstrates that IgG1 antibodies are responsible for the ability of immune serum to transfer cutaneous basophil-associated immune resistance against tick feeding in guinea pigs.
Maturational state of lymphoid cells in long-term bone marrow cultures.
Authors: Dorshkind K , Phillips R A 
Published: December 2022

Abstract
B lymphocytes are not produced in long-term bone marrow cultures (LTBMC) and controversy exists regarding T cell differentiation in the cultures. By analyzing the kinetics of B cell reconstitution in lethally irradiated mice by cells from fresh bone marrow or from LTBMC, we have determined that B cell differentiation is blocked at an early stage in the cultures. Colony-forming B cells (CFU-B) are generated more rapidly and to higher levels in recipients of fresh bone marrow cells than in animals grafted with cells from LTBMC. The data further indicate that the adherent fraction cells from LTBMC are an enriched source of B cell precursors as compared to non-adherent cells and that B cell reconstitutive potential and levels of spleen colony-forming stem cells (CFU-S) do not correlate with one another. Under appropriate culture conditions, T lymphocytes are detectable in LTBMC. These Thy-1-positive cells proliferate in the cultures and can generate cytotoxic responses. These effectors originate from Thy-1-positive cells present in the initial bone marrow inoculum used to establish the cultures and have not differentiated from mature Thy-1-negative progenitors in vitro.
Functional significance of Tac antigen expressed on activated human T lymphocytes: Tac antigen interacts with T cell growth factor in cellular proliferation.
Authors: Miyawaki T , Yachie A , Uwadana N , Ohzeki S , Nagaoki T , Taniguchi N 
Published: December 2022

Abstract
Cultured human T cells (CTC), which are grown in conditioned medium containing T cell growth factor (TCGF), proliferate in response to TCGF. It has been shown that an antigen (Tac) defined by a monoclonal antibody, termed anti-Tac antibody, is expressed on human T cells activated by mitogens or antigens and CTC grown in the presence of TCGF. To elucidate the functional significance of Tac antigen expressed on activated T cells, we studied the effect of anti-Tac antibody on TCGF-dependent proliferation of CTC. The addition of anti-Tac antibody strongly inhibited the proliferation of CTC induced by TCGF. This inhibition was observed only when the antibody was added at the early phase of culture, but not when the addition of the antibody was delayed beyond 24 hr of culture. Seven-day-old PHA-induced T cell blasts, but not fresh peripheral blood lymphocytes, were able to absorb TCGF activity in conditioned medium, as assessed by the DNA synthesis of CTC. When PHA-induced blasts were treated with anti-Tac antibody before absorption, their capacity to absorb TCGF activity was almost completely eliminated. In contrast, absorption of TCGF by PHA-induced blasts was not significantly reduced even when they were pretreated with other monoclonal antibodies (anti-Ia, OKT9, or OKT10) with specificity for antigens expressed on activated T cells. Based on the view that TCGF interacts with activated T cells via specific membrane receptors, these observations suggested that anti-Tac antibody might specifically block the binding of TCGF to the corresponding membrane binding sites, resulting in the inhibition of TCGF-dependent proliferation of CTC. Tac antigen expressed on activated T cells seems to participate in responding process of activated T cells to TCGF.
Suppression of human natural and antibody-dependent cytotoxicity by soluble factors from unstimulated normal lymphocytes.
Authors: Nair M P , Schwartz S A 
Published: December 2022

Abstract
Serum-free culture supernatants of unstimulated normal human peripheral blood mononuclear cells contain soluble suppressor factor(s) (SSF) that significantly inhibit natural (NK) and antibody-dependent cellular cytotoxic (ADCC) activities of allogenic lymphocytes against a variety of target cells. Lymphocytes precultured with increasing concentrations of SSF showed a dose-dependent suppressive effect on these cytotoxic functions that was optimal at a concentration of 20% volume/volume. Adherent cells were not required for the production of SSF. Suppression was evident even at higher effector: target cell ratios and the inhibition was not reversed by washing lymphocytes. SSF was not itself cytotoxic, was stable at 56 degrees C, and its suppressive effect was maximal after 72 hr of incubation with effector lymphocytes. Initial estimate of the molecular weight of SSF by ultra-filtration was less than 20,000 daltons. Gel filtration of SSF on Sephacryl S-200 resulted in the elution of two peaks of activity; one in the region between markers of 13,700 and 25,000 daltons, and the other less than 13,700 daltons. Both fractions demonstrated significant suppressive activity on NK and ADCC functions of allogenic lymphocytes. SSF inhibition of NK activity could be partially reversed by incubating lymphocytes for 1 hr with human leukocyte interferon (IF) and almost completely reversed after 24 hr of IF treatment. A few selected monosaccharides (alpha-methyl-D-mannoside, L-fucose and L-rhamnose) showed a dose-dependent blocking effect on SSF activity, which suggests that SSF may act via receptor sites recognized by these sugars. As demonstrated for other lymphocyte functions, NK and ADCC activities may also be modulated by SSF elaborated by normal PBL.
Differential expression of Ia glycoprotein complexes in F1 hybrid mice detected with alloreactive cloned T cell lines.
Authors: Conrad P J , Lerner E A , Murphy D B , Jones P P , Janeway C A 
Published: December 2022

Abstract
T cell lines alloreactive to Aeb:E alpha Ia antigen complexes have been prepared and used to determine the relative amount of Aeb:E alpha expressed by stimulator cells in homozygous recombinant and F1 mice expressing these complexes. We find that homozygous cells stimulate most strongly and therefore probably express the highest density of Aeb:E alpha. Among heterozygotes, H-2bxd F1 mice preferentially express Aeb:E alpha d complexes, H-2bxa F1 mice express relatively fewer Aeb:E alpha k complexes, and H-2bxu F1 mice express preferentially Aeu:E alpha u complexes. This differential association of Aeb chains with E alpha chains thus influences the biologic activity of these Ia antigens in this and other functional assays. The functional data are supported by biochemical analysis of Aeb:E alpha complex expression. These findings suggest that a reanalysis of HLA-DR associations with human diseases should be undertaken in which both HLA-DR alleles are included, with the prediction that certain combinations would show greater susceptibility, whereas others would show less susceptibility than predicted from the susceptibility associated with presence of a single allele at HLA-DR.