bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ontogeny of Cell-Mediated Cytotoxicity: Induction of CTL in Early Postnatal Thymocytes
Authors: Widmer M. B. , Cooper E. L. 
Published: January 2023

Abstract
In this study we characterized the time when cytotoxic T lymphocytes (CTL) can be induced in the thymus and spleen from their immediate CTL precursors (CTL-P). In contrast to fetal or newborn thymus, the thymus of 1 to 2-day-old C57BL/6 mice contained cells that, after cultivation in vitro with allogeneic DBA/2 stimulating cells, exhibited high levels (as great or greater than that induced in adult thymocytes) of CTL activity as measured by the ability to lyse P815 (DBA/2) tumor target cells. However, CTL activity induced in spleen cells remained low during the first 5 days of life, increased sharply between 6 to 9 days, and reached adult levels at 11 to 20 days. Furthermore, early postnatal spleen cells did not suppress the adult splenic CTL response. These results suggest 1) that the full potential to generate CTL in response to an allogeneic stimulus commences in the thymus on the first day after birth and 2) a different temporal appearance of immediate CTL precursors in the thymus and spleen.
Characterization of a Xenoantiserum Produced Against Three Molar KCl-Solubilized Antigens Obtained from a Non-T, Non-B (Pre-B) Acute Lymphoblastic Leukemia Cell Line
Authors: LeBien Tucker W. , Hurwitz Richard L. , Kersey John H. 
Published: January 2023

Abstract
Antisera were produced in rabbits to 3 M KCl solubilized antigens of a recently established leukemia cell line. The cell line (NALM-6-M1) was established from an individual with acute lymphoblastic leukemia (ALL), and has the characteristics of a pre-B cell, i.e., it is cytoplasmic IgM+, surface immunoglobulin-, anti-thymocyte serum- (CIgM+, SIg-, ATS-). One unabsorbed antiserum did not react with T cells, and after a single absorption with a B lymphoblastoid cell line (positive for p23,30, an Ia-like antigen), the antiserum reacted with cells from eight of 10 patients with non-T, non-B ALL and cells from two of two patients with chronic myelogenous leukemia in lymphoid blast crisis (CML-LBC). The absorbed antiserum did not react with surface immunoglobulin+ chronic lymphocytic leukemia (SIg+ CLL) cells; acute myelogenous leukemia (AML) cells; anti-thymocyte serum+, E rosette+, acute lymphoblastic leukemia (ATS+, E+ ALL) cells; cells from patients with chronic myelogenous leukemia in myeloid blast crisis (CML-MBC); normal peripheral blood T cells; PHA-induced blasts; leukemia T cell lines; or B lymphoblastoid cell lines. The specificity of the absorbed antiserum suggests that it was detecting antigens of non-T, non-B ALL and CML-LBC, and may be recognizing a “common” ALL antigen. We conclude that 3 M KCl solubilization of membrane antigens from the NALM-6-M1 leukemia cell line provides an effective immunogen for producing antisera reactive with non-T, non-B ALL and CML-LBC. This offers an approach to the biochemical characterization of the antigen(s) common to these two leukemias and allows further evaluation of the relationship between the common ALL antigen and antigens of normal and malignant cells of the pre-B phenotype.
Requirements for Mitogenic Stimulation of Murine B Cells by Soluble Anti-IgM Antibodies
Authors: Sidman Charles L. , Unanue Emil R. 
Published: January 2023

Abstract
The requirements for the stimulation of proliferation in murine B cells by soluble anti-IgM antibodies were examined. For optimal stimulation, the presence of both 2-mercaptoethanol (2-ME) and fetal calf serum (FCS) was found necessary for both anti-IgM and LPS-stimulated proliferation. This requirement could be substituted by a stable and alkylation-insensitive cofactor produced in serum by exposure to 2-ME followed by dialysis. Filler thymocytes could also partially substitute for the 2-ME-FCS factor. In the presence of this cofactor, accessory cells were not necessary for the response of B cells to anti-IgM and LPS.
The proliferative response was found in B cells from adult mice. However, B cells from neonatal mice did not respond to anti-IgM antibodies under any conditions. Whereas the proliferative response to LPS was maximal by 2 to 3 weeks of age, the response to anti-IgM was still not maximal at 2 months of age.
Reactivity of the anti-Ig antibodies against the IgM Fc determinants was necessary for stimulation, whereas reactivity to Fab determinants had no effect. Bivalent F(ab′)2 anti-IgM antibody fragments were more stimulatory than intact antibodies, but monovalent Fab fragments were totally nonstimulatory. These findings indicate both a requirement for receptor cross-linking and an inhibitory effect produced by the antibody Fc fragment.
B cells had to be continuously exposed to both anti-IgM and the 2-ME-FCS factor in order to proliferate; neither agent exerted its total effect in a short period of time.
Passive Enhancement of Mouse Skin Allografts by Alloantibodies Is Fc Dependent
Authors: Capel Peter J. A. , Tamboer Wim P. M. , de Waal Robert M. W. , Jansen Jan L. J. , Koene Robert A. P. 
Published: January 2023

Abstract
The capacity of F(ab′)2 fragments of alloantibodies to enhance mouse allografts was studied in B6AF1 recipients of B10.D2 skin grafts. F(ab′)2 obtained by digestion of B6AF1 anti-B10.D2 antibodies was purified by means of affinity chromatography, with anti-subclass antisera and protein A. The degree of contaminating IgG was less than 0.02%.
Administration of F(ab′)2 with an antigen-binding capacity similar to the IgG from which it originated, inhibited acute antibody-mediated graft rejection but was unable to induce enhancement. Even a dose that was 130 times the molar amount of the minimal enhancing dose of undigested IgG2 was ineffective. We conclude, therefore, that passive enhancement of mouse skin allografts by alloantibodies requires the Fc part.
The Expression of the Allelic Gene of Murine C3 in Fetal and Neonatal Mice
Authors: Amano Shigetoyo , Natsuume-Sakai Shunnosuke , Hayakawa Jun-Ichiro , Takahashi Morinobu 
Published: January 2023

Abstract
A single co-dominant gene locus linked to H-2, tentatively designated C3-1 locus by us, controls allotypic variation of murine complement (C) C3 as previously described. We used this genetically determined variation of murine C3 as a marker in the probe for the synthesis of this C component in fetal and neonatal mice. Phenotypes of murine C3 were determined by a combined use of analytical isoelectric focusing and immunofixation and by antigenic analysis with alloantiserum directed to the gene product of one of the alleles at the C3-1 locus.
Fetuses and neonates of inbred mice (BALB/c and NC strains), F1 hybrids, and backcross progeny express the same C3 phenotype as the one observed in adult mice of the corresponding C3 genotype. No evidence for the occurrrence of “fetal C3” in fetal mice was obtained. Furthermore, allotypic differences of C3 between mother and fetus or neonates provide evidence that murine C3 is synthesized by fetus or neonate and is not transferred from mother transplacentally nor via colostrum. In summary, mice synthesize C3 according to the allelic structural gene(s) at the C3-1 locus even during their early developmental life.
Possible Role of Arachidonic Acid and Its Metabolites in Mediator Release from Rat Mast Cells
Authors: Sullivan Timothy J. , Parker Charles W. 
Published: January 2023

Abstract
The role of arachidonic acid (AA) metabolism in the release of inflammatory mediators from rat mast cells was studied. Eicosa-5,8,11,14-tetraynoic acid (ETYA), an acetylenic analog of AA, was found to inhibit histamine release induced by anti-IgE, concanavalin A (Con A), or the ionophore A-23187 with ID50 values of 65, 50, and 17 µM, respectively. Mediator release was not affected by aspirin or indomethacin in concentrations up to 60 µM. Addition of free AA (0.1 to 100 µM) to unstimulated mast cells did not initiate noncytotoxic mediator release. Preincubation of mast cells with 1 to 10 µM AA inhibited subsequent release induced by anti-IgE or Con A (up to 38%). This inhibition of release was blocked if aspirin (10 µM) or indomethacin (10 µM) was present, suggesting that AA inhibition was mediated by cyclo-oxygenase products. When AA was added after secretion was initiated by anti-IgE or Con A, a modest potentiation of release was noted. These studies suggest that AA metabolism by enzyme systems other than cyclo-oxygenase is an integral part of the mast cell secretory process. Availability of free AA, however, does not appear to be a sufficient condition to initiate secretion by otherwise unstimulated cells. Activation of mast cells by secretory signals appears to lead to altered AA metabolism which in turn appears to be involved in the secretion of inflammatory mediators.
Electrical Measurements of Complement-Mediated Membrane Damage in Cultured Nerve and Muscle Cells
Authors: Stephens Cathy L. , Henkart Pierre A. 
Published: January 2023

Abstract
Cultered neuroblastoma-glioma hybrid cells and primary mouse and rat muscle cells were studied by using intracellular microelectrodes to monitor membrane electrical potential and resistance changes during complement-mediated lysis. The cell membrane was TNP modified under mild conditions and subsequently coated with rabbit IgG anti-TNP, with no electrical changes observed. However, upon addition of guinea pig C the membrane potential dropped from ∼-50 mv to &lt;-12 mv within a few minutes, with parallel decreases in electrical resistance. Ten to 60 min after these electrical changes the cells became stainable with trypan blue. No electrical changes or trypan blue staining was observed in the absence of antibody or with heat-inactivated C. With more dilute C so that only a fraction of cells became trypan blue positive, all cells nevertheless showed the membrane electrical changes; surviving cells recovered their original membrane properties within 1 hr. Thus the C-mediated damage to the membrane measured electrically is not in itself sufficient to ensure the subsequent death of the cell. The early electrical changes observed appear to be comparable to increases in 86Rb efflux measured by others.
Total lymphoid irradiation in kidney and liver transplantation in the baboon: prolonged graft survival and alterations in T cell subsets with low cumulative dose regimens.
Authors: Myburgh J A , Smit J A , Stark J H , Browde S 
Published: January 2023

Abstract
Prolonged kidney and liver allograft survival was produced in baboons by low cumulative doses (500 to 1200 rad) of total lymphoid irradiation (TLI). Continuing normal graft function for more than 1 yr after transplantation was seen in 10 animals in this series. The longest survivor (greater than 4 years) rejected a third party kidney allograft in typically acute fashion 1 yr after the original transplantation. The dose-response effect was parabolic, with a cumulative dose of 800 rad given as twice weekly fractions of 100 rad each being the most effective. With smaller cumulative doses (500 or 600 rad) results were improved if TLI was administered as a larger number of smaller fractions. These regimens are free of the radiation related mortality observed in earlier studies with larger cumulative doses. As in previous studies, the injection of donor bone marrow was not essential for prolonged and continuing graft survival. The field irradiated was extensive, and included a substantial part of the of the hemopoietic bone. Restricting the field irradiated to that approximating what is used clinically in patients with Hodgkin's disease resulted in markedly poorer graft survival. Alterations in T cell subpopulations were studied in these baboons with the use of the anti-human monoclonal antibodies OKT11 (anti-total T cells), OKT4 (anti-T helper cells; Th), and OKT8 (anti-T suppressor/cytotoxic cells, Tsc), which cross-react with baboon lymphocytes. After completion of TLI but before transplantation, the relative percentage of Tsc cells fell and the percentage of Th and the Th/Tsc ratio rose. Transplantation was followed by an inversion of this ratio due to reciprocal changes in the percentages of Th and Tsc cells. This pattern persisted and increased until 6 mo after transplantation, when it reverted to that seen in untreated control animals. This was maintained in long surviving animals up to 17 mo after transplantation. Transplantation was also followed by a marked early increase in the percentage of Ia+ (OKIa1 anti-human monoclonal antibody) total T, T4+, and T8+ cells. If findings in the human, in which activated suppressor but no cytotoxic T cells are Ia+, can be extrapolated to the baboon, a possible explanation for the serial changes observed in the present studies may be that transplantation after TLI results in a polyclonal expansion of nonspecific suppressor T cells. These disappear with time leaving specific suppressor T cells that may be responsible for continuing graft acceptance. Formal proof of this hypothesis will require appropriate functional studies.
Mechanism of cell-mediated cytotoxicity at the single cell level. VI. Direct assessment of the cytotoxic potential of human peripheral blood non-lytic effector-target cell conjugates.
Authors: Bonavida B , Lebow L T , Bradley T P 
Published: January 2023

Abstract
Single cell cytotoxicity assays reveal that a large percentage of lymphocytes are unable to kill attached targets in a 4- to 18-hr assay. Additional signals (in the form of lectin or anti-target antibody) delivered to target-bound lymphocytes enable these previously non-lytic lymphocytes to kill attached target cells. This finding was obtained by using a modification of the single cell assay, in which lectin or target cell antibody is incorporated into agarose with preformed lymphocyte-target conjugates. Human peripheral blood lymphocytes (PBL) or Percoll density gradient-enriched large granular lymphocytes (LGL) were used as effector cells in natural killer (NK), antibody-dependent cellular cytotoxicity (LDCC) assay systems. The targets used were NK-sensitive K562 and Molt-4 and NK-insensitive Raji. Several findings were made in the modified single cell assay, namely a) the frequency of cytotoxic NK or ADCC effector cells was not augmented, suggesting that the initial trigger was sufficient for lytic expression in these instances. Furthermore, these results showed that the NK-sensitive targets used do not bind nonspecifically to the LDCC effector cells. K562 coated with Con A, however, serve as LDCC targets. b) The frequency of two target conjugate lysis by NK/K effectors was not augmented by Con A. These results suggest that Con A does not potentiate the killing of multiple targets bound to a single cytotoxic lymphocyte. c) Although conjugates formed between LGL or PBL and NK-insensitive Raji are non-lethal, significant lysis was observed when these conjugates were suspended in Con A or antibody agarose. These results demonstrate that Raji bind to cytotoxic NK, K, and LDCC effector cells, but are lysed only when the appropriate trigger is provided. d) The cytotoxic potential of non-lytic conjugates appears to lie within the low density Percoll fraction, although the high density lymphocytes are able to nonlethally bind to targets. Altogether the results demonstrate that target recognition and/or binding by the effector cells is a distinct event from the trigger or lytic process. The implications of these findings are discussed.
Secretion of immunoglobulin A by human milk leukocytes initiated by surface membrane stimuli.
Authors: Weaver E A , Rudloff H E , Goldblum R M , Davis C P , Goldman A S 
Published: January 2023

Abstract
Some of the requirements for release of immunoglobulin A (IgA) from human milk leukocytes during phagocytosis were investigated. The role of particle adherence in IgA release was studied by using an in vitro model of frustrated phagocytosis in which human milk leukocytes were incubated with latex particles too large to ingest. Release of IgA was significantly increased from control values within 30 min in these leukocytes. A similar increment in IgA release also occurred when human milk leukocytes were incubated with other surface membrane stimuli, e.g., NFMP and phorbol. No increase in IgA release was found, however, in cells incubated with zymosan-activated serum. In addition, the release of IgA was blocked by inhibitors of actin filaments (cytochalasin B) and microtubules (colchicine). Thus, IgA is released from human milk leukocytes by secretory mechanisms that are initiated by certain membrane stimuli, some of which are shared by peripheral blood neutrophils and monocytes. Because human milk leukocytes appear to be refractory to C5a or other activated complement components and are blocked by cytochalasin B, it appears that these unusual cells may be uniquely adapted to play a role in the immunologic protection of the neonate.
The use of monoclonal antibodies as probes of the three-dimensional structure of human complement factor D.
Authors: Niemann M A , Kearney J F , Volanakis J E 
Published: January 2023

Abstract
The monoclonal antibodies (MAb) were studied for their binding specificities and their effects on the hemolytic and proteolytic activities of human D. One Mab, FD10-1, was obtained from mice immunized with native D; the other, JA4-2, was similarly obtained from mice immunized with BSA coupled to a synthetic nonapeptide (Arg-Ile-Leu-Gly-Gly-Arg-Glu-Ala-Tyr) containing the seven NH2-terminal amino acids of D. By using a PEG-precipitation assay system, lactoperoxidase-iodinated D was precipitated by FD10-1 cell culture supernatant as well as by the purified MAb. Conversely, with the use of the same assay system, neither the JA4-2 cell culture supernatant nor the purified MAb precipitated any significant amount of 125I-D. In contrast, by using a solid-phase binding assay, radiolabeled JA4-2 as well as FD10-1 bound to D-coated wells. In addition, the binding of purified JA4-2 to D-coated wells could be completely inhibited by the nonapeptide, whereas the binding of purified FD10-1 at equivalent concentrations was unaffected. These binding studies correlated with the results of functional assays. FD10-1 was found to inhibit the hemolytic activity of the alternative complement pathway in human serum as well as the cleavage of radiolabeled B by D in the presence of cobra venom factor, whereas JA4-2 had no significant inhibitory effect in either of these assays. These data suggest that the NH2-terminus of native D, like that of other active serine proteases, is buried inside the molecule where it is inaccessible to the bulky JA4-2 MAb.
T cell-derived glucosteroid response-modifying factor (GRMFT): a unique lymphokine made by normal T lymphocytes and a T cell hybridoma.
Authors: Fairchild S S , Shannon K , Kwan E , Mishell R I 
Published: January 2023

Abstract
Mouse spleen cells and a murine T cell hybridoma, FS6 14.13.1, produce a glucosteroid response-modifying factor (GRMFT) after stimulation with concanavalin A. GRMFT blocks glucosteroid suppression of helper T cell function and the growth of granulocyte/macrophage progenitor cells in vitro. IL 1 also protects helper T cells and myeloid precursors from glucosteroid suppression. This suggests that GRMFT and IL 1 act congruently to ensure that an effective immune response is generated when endogenous glucosteroid levels are elevated. To understand the role of GRMFT in normal immune responses and in disease states characterized by imbalances in the immune system, we began to purify and characterize GRMFT. GRMFT appears to be distinct from other well-characterized T cell-derived factors. GRMFT is larger than IL 2 as determined by gel exclusion chromatography and is completely separated from IL 2 by isoelectric focusing. Furthermore, purified IL 2 does not have GRMFT activity. Purified IL 3 also lacks GRMFT activity, and conditions that inactivate immune interferon have no effect on GRMFT. Thus, GRMFT is different from IL 2, IL 3, and immune interferon. GRMFT also lacks activity in the thymocyte co-mitogenic assay and is therefore different from IL 1. Finally, FS6 14.13.1 reportedly does not produce TRF or CSF, which suggests that GRMFT is different from these molecules as well.
Inhibition of entry of Plasmodium falciparum and P. vivax sporozoites into cultured cells; an in vitro assay of protective antibodies.
Authors: Hollingdale M R , Nardin E H , Tharavanij S , Schwartz A L , Nussenzweig R S 
Published: January 2023

Abstract
Plasmodium falciparum and P. vivax sporozoites were observed to invade cultured human hepatoma cells in vitro. Monoclonal antibodies to the circumsporozoite (CS) protein of each of these malarial species blocked invasion. Inhibition was species-specific, but was independent of the geographic origin of each strain. Because these monoclonal antibodies have been shown to diminish or abolish sporozoite infectivity to susceptible primate hosts, it is suggested that inhibition of invasion of sporozoites (ISI) into cultured cells may represent in in vitro assay for protective antibodies. This was confirmed by the finding that serum taken from volunteers immune to sporozoite challenge also totally blocked sporozoite invasion. The ISI assay also detected naturally acquired invasive-neutralizing antibodies in areas endemic for malaria. This ISI assay may therefore be useful in determining the incidence of inhibitory anti-sporozoite antibodies in general populations, and allow the monitoring of the effect of an anti-malarial vaccine using sporozoite-derived antigens.