bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fibronectin fragment(s) are chemotactic for human peripheral blood monocytes.
Authors: Norris D A , Clark R A , Swigart L M , Huff J C , Weston W L , Howell S E 
Published: December 2022

Abstract
Both plasma-derived and cell-derived fibronectin are deposited at sites of inflammation and wound healing and are associated with migrating cell populations including monocytes/macrophages. We found that fibronectin fragments generated by endogenous protease(s) are potent chemoattractants for human peripheral blood monocytes, whereas intact fibronectin has no activity. Fibronectin preparations produced by gelatin affinity chromatography in the absence of protease inhibitors contained 90 to 220 kd fragments and had potent chemotactic and chemokinetic activity for monocytes but no activity for human neutrophils or lymphocytes. The addition of phenylmethylsulfonyl fluoride to plasma reduced but did not eliminate the recovery of fibronectin fragments and likewise reduced the chemotactic activity. When the preparations were further purified by DEAE ion exchange and Sepharose 4B molecular sieve chromatography, however, intact fibronectin was recovered that lacked both chemotactic and chemokinetic activity. When fragment-poor fibronectin was allowed to sit at 25 degrees C in NaN3 but without protease inhibitors, increased fragmentation and increased chemotactic activity were noted. In addition, chemotactically active small m.w. fragments arose from high m.w. fragments or from intact fibronectin as demonstrated by rechromatography experiments over Sephadex G-150. These findings suggest that proteolytic cleavage of fibronectin during inflammatory processes produces fragments that selectively augment the recruitment of monocytes into tissue sites of inflammation.
Isolation and characterization of a monoclonal antibody-resistant antigenic mutant of Toxoplasma gondii.
Authors: Kasper L H , Crabb J H , Pfefferkorn E R 
Published: December 2022

Abstract
Several monoclonal antibodies against Toxoplasma gondii were parasiticidal in the presence of normal human serum as measured by reduction in plaque titer or in assays that detected lysis. One monoclonal antibody, G, was used to select a resistant mutant from a large population of chemically mutagenized wild-type parasites. This mutant retained the wild-type sensitivity to other monoclonal antibodies and to polyclonal antisera. A comparison of surface radioiodinated wild-type and mutant parasites by using one and two-dimensional electrophoresis showed that the mutant lacked a protein (or proteins) of approximate m.w. 22,000. An immunoprecipitation procedure using monoclonal antibody G yielded a protein(s) of this m.w. from surface radioiodinated wild-type T. gondii but not from surface radioiodinated mutant parasites.
Variable and common antigens of Babesia bovis parasites differing in strain and virulence.
Authors: Kahl L P , Anders R F , Rodwell B J , Timms P , Mitchell G F 
Published: December 2022

Abstract
Virulent and avirulent K strain (KV and KA) and virulent L strain (LV) Babesia bovis parasites were biosynthetically labeled with 35S-methionine. Labeled proteins, extracted in detergent from infected cultures, were analyzed by two-dimensional gel electrophoresis. Protein antigens common to these forms of babesia and those specific for strain and correlating with the degree of virulence were identified by immunoprecipitation with antisera. Dominant labeled protein antigens were found to differ both between the K and L strains of B. bovis and between virulent (KV) and avirulent (KA) forms of the K strain. Partial cleavage of biosynthetically labeled proteins by staphylococcal V-8 protease and peptide mapping revealed that no extensive amino acid homology existed between the candidate variant antigens. KA B. bovis parasites are currently in use as a live attenuated vaccine for bovine babesiosis in Australia. Antigens that are better expressed in KA relative to virulent strains may therefore be markers of avirulence and/or candidate "host-protective antigens" of B. bovis. At least one protein (Mr 43,000) was identified as being a dominant labeled antigen of KA that is poorly represented in the KV and LV B. bovis isolates.
Limitation of VSV infection by the host's response to VSV-associated cellular antigens.
Authors: Hecht T T , Paul W E 
Published: December 2022

Abstract
It has been reported that during the maturation of enveloped viruses, host proteins such as H-2 antigens of the mouse associate with the budding viruses. This finding led us to investigate the possible biologic significance of this association. In our studies, we examined, with purified vesicular stomatitis virus (VSV) from various sources, the in vivo infection of mice immunized with allogeneic tumors. Immunization of H-2k mice with an H-2d tumor caused the limitation of replication, within the spleen, of VSV derived from an H-2d cell line compared with the replication of VSV derived from an H-2k line. Conversely, immunization of H-2d mice with an H-2k tumor caused the limitation of replication of VSV derived from an H-2k cell line. Viral mixture experiments ruled out indirect inactivation or inhibition of virus replication by nonspecific factors, such as immune interferon, as having a major role in the observed limitation of VSV replication. We conclude that virus infections can be limited by an immune response directed against the specific host surface antigen that the virus carries in its envelope.
Regulation of human natural killing. II. Protective effect of interferon on NK cells from suppression by PGE2.
Authors: Leung K H , Koren H S 
Published: December 2022

Abstract
Activation of human natural killer (NK) cells in vitro with interferon (IFN) and poly I:C results in a partial loss of sensitivity of these cells to suppression by PGE2. The acquired resistance to suppression can be induced with the large granular lymphocytes (LGL) in the absence of monocytes. With K562, HSB, and CEM used as NK target cells, the IFN-induced resistance to suppression by PGE2 is observed with all three target cells. Furthermore, ADCC activity of IFN-activated cells against tumor (SB-TNP) and erythroid (CRC-TNP) target cells is also less susceptible to suppression by PGE2. The dual effect of IFN on NK cells is prompt; the augmentation of NK activity and the acquired resistance to suppression by PGE2 can be seen after 3 hr of treatment with IFN. Both of these characteristics seem to be quite stable for at least 24 hr. Spleen cells from mice (CBA, C3H, and BALB/c nude) treated in vivo with poly I:C also acquire partial resistance to suppression by PGE2. Our data therefore suggest that IFN-stimulated NK cells are protected from suppression by PGE2. Biologically, the IFN-induced protective effect may be beneficial to host resistance to neoplasia.
Neutralization of native human gamma interferon (HuIFN gamma) by antibodies to a synthetic peptide encoded by the 5' end of HuIFN gamma cDNA.
Authors: Johnson H M , Langford M P , Lakhchaura B , Chan T S , Stanton G J 
Published: December 2022

Abstract
A synthetic peptide corresponding to the N-terminal amino acid sequence of human gamma-interferon (HuIFN gamma), based on the cDNA sequence, was used to produce antibodies in rabbits that were reactive with native HuIFN gamma. Antibodies from all immunized rabbits neutralized the antiviral activity of HuIFN gamma. Significant neutralization of other HuIFN and mouse IFN was not observed. The peptide had the sequence Cys-Tyr-Cys-Gln-Asp-Pro-Tyr-Val-Lys-Glu-Ala-Glu-Asn-Leu-Lys-Lys-Tyr-Phe-Asn-Ala ,and was coupled to keyhole limpet hemocyanin by disulfide linkage with the use of cystamine. The specificity of the antibodies produced to the peptide was compared to that of antibodies produced to native HuIFN gamma by neutralization of HuIFN gamma and by reactivity with peptide in the enzyme-linked immunosorbent assay (ELISA). The ratio of anti-peptide antibody neutralization of HuIFN gamma vs reactivity with peptide in the ELISA was at least 28-fold lower than for anti-HuIFN gamma antibody. Thus the antibodies to peptide and to HuIFN gamma were directed primarily against different determinants on native HuIFN gamma or the anti-HuIFN gamma antiserum probably contained antibodies to additional determinants. The anti-peptide antibodies should be useful for further characterization and purification of HuIFN gamma.
Lyt phenotype of H-2b CTL effectors and precursors specific for the SV40 transplantation rejection antigen.
Authors: Flyer D C , Anderson R W , Tevethia S S 
Published: December 2022

Abstract
The immune effector cells mediating the in vitro immune response to the SV40 transplantation rejection antigen were characterized by using monoclonal antibody directed against lymphocyte differentiation (Lyt) antigens. Two distinct T lymphocyte populations were found to be responsible for the in vitro lysis of SV40-transformed cells, and Lyt 1+,2+ cytotoxic T lymphocyte (CTL) that is present in the spleens of SV40 immunized mice 9 days postimmunization and an Lyt 1-,2+ CTL that is generated by secondary in vitro stimulation of in vivo primed spleen cells. During secondary in vitro stimulation of SV40 immune spleen cells obtained 9 days postimmunization, a shift in the Lyt phenotype of the CTL from Lyt 1+,2+ to Lyt 1-,2+ is observed. Although the Lyt 1-,2+ CTL can be derived from Lyt 1-,2+ noncytotoxic memory cells, it is not known whether the Lyt 1+,2+ CTL differentiates into an Lyt 1-,2+ CTL during in vitro stimulation.
An adherent cell lyses virus-infected targets: characterization, activation, and fine specificity of the cytotoxic cell.
Authors: Letvin N L , Kauffman R S , Finberg R 
Published: December 2022

Abstract
We have previously reported that mice with defective T lymphocyte function clear a primary reovirus type 1 infection in a normal fashion. The present studies were initiated to determine what cells may play a role in the clearance of this primary infection. We show that macrophages from unprimed mice are capable of lysing reovirus type 1-infected target cells in the absence of specific antibody. Macrophages from nu/nu mice have higher levels of this lytic activity than macrophages from nu/+ and normal mice. In addition, PEC from endotoxin nonresponsive C3H/HeJ mice have virtually no anti-viral lytic activity, while PEC from C3H/FeJ mice have high levels of such activity. Incubation of PEC from C3H/HeJ mice overnight in Con A supernatants restores this lytic activity. PEC are capable of lysing reovirus type 1-infected target cells but not those infected with type 3 reovirus. Using intertypic recombinant viruses, we show this striking target cell specificity to be a property of the sigma 1 protein, the viral hemagglutinin.
Production of prostaglandin E and an interleukin-1 like factor by cultured astrocytes and C6 glioma cells.
Authors: Fontana A , Kristensen F , Dubs R , Gemsa D , Weber E 
Published: December 2022

Abstract
When treated with lipopolysaccharide (LPS), cultured murine astrocytes released significant amounts of prostaglandin E, which caused an inhibition of the in vitro proliferative response of C3H/HeJ thymocytes to mitogen. In addition, an interleukin 1 (IL 1)-like factor secreted by LPS-treated glia cell cultures and by C6 glioma cells was detected. The characterization of the factor as an IL 1-like mediator is based on the findings that the factor 1) enhances the mitogen-induced thymocyte proliferation, 2) exhibits no interleukin 2 (IL 2) activity, but 3) augments IL 2 production by mitogen-stimulated thymocytes, and 4) has a m.w. between 13,500 and 18,000 when generated in serum-free conditions. These observations suggest that astrocytes may interact with the immune system by elaborating nonspecific factors that modulate lymphocyte proliferation. This property of astrocytes may be important in the generation of specific immune responses in the brain, which is considered to be an immunologically privileged organ as it is anatomically sequestered from the immune system.
Contrasting effects of lactoferrin on human lymphocyte and monocyte natural killer activity and antibody-dependent cell-mediated cytotoxicity.
Authors: Nishiya K , Horwitz D A 
Published: December 2022

Abstract
Iron and the iron-binding protein lactoferrin (LF) have significant effects on natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC). Human adherent and nonadherent blood mononuclear cells were incubated with K562 cells and antibody-sensitized Chang cells in short-term chromium-release assays. Ferric citrate (10(-3) M) inhibited both adherent and nonadherent NK cell activity, but had no effect upon ADCC. LF markedly affected adherent monocyte cytotoxicity, but had no effect on nonadherent lymphocytes. LF enhanced NK in a dose-dependent manner, but similar concentrations paradoxically inhibited ADCC. LF acted directly upon the adherent effector cell because pretreatment of cells for 30 min was sufficient for enhancement. Fe-saturated LF as well as the unsaturated protein enhanced adherent cell NK. Transferrin in all concentrations tested did not alter NK activity. These studies show inhibitory effects of iron on immune function in addition to those previously described and reveal a new regulatory role for LF. The selective effect of LF on adherent cells provides further evidence that monocytes, at least in the adherent state, can have potent NK activity. The opposite effects of LF on NK and ADCC are unexplained and may serve as a probe to define the mechanisms involved.
Hanganutziu-Deicher antibodies in infectious mononucleosis and other diseases.
Authors: Morito T , Kano K , Milgrom F 
Published: December 2022

Abstract
An enzyme immunoassay (EIA) was developed for the detection of heterophile, Hanganutziu-Deicher (H-D) antibodies in sera of patients with infectious mononucleosis (IM) and various other diseases. The EIA with a high m.w. glycoprotein (HMWGP) isolated from bovine erythrocyte stromata was shown to detect H-D antibodies directly, in spite of higher titers of Paul-Bunnell (P-B) antibodies in the IM sera. Absorption and inhibition studies of IM sera demonstrated H-D specificity of the antibodies combining with HMWGP in the EIA. The H-D antibodies were found in sera of 56% Caucasians and 27% of Japanese suffering from IM. The vast majority of the H-D antibodies in IM sera was of IgM class. Sera of patients with various other diseases also gave positive results: rheumatoid arthritis, 22%; syphilis, 19%; cancer of the gastrointestinal tract, 13%; and lepromatous leprosy 9.7%. The incidence of positive results in control sera from apparently healthy subjects was less than 4%. Results of this study confirmed our previous observation that whereas P-B antigens appear in immunogenic form in only IM, the H-D antigen is expressed as an immunogen in various diseases including IM.
Immune deficiency in the X-linked lymphoproliferative syndrome. II. Immunoregulatory T cell defects.
Authors: Lindsten T , Seeley J K , Ballow M , Sakamoto K , St Onge S , Yetz J , Aman P , Purtilo D T 
Published: December 2022

Abstract
Surface phenotypic markers and the function of lymphocytes in patients affected with the X-linked lymphoproliferative syndrome (XLP) were studied. This syndrome is characterized by a defective response to infection with Epstein Barr virus (EBV). Normal numbers of B and T cells were detected with anti-Ig and monoclonal OKT3 antisera, respectively. T cell subset values, however, were persistently altered: cells reacting with OKT8 were significantly elevated in five of nine patients, accompanied by a slight decrease in the percentage of OKT4-positive cells, leading to abnormally low OKT4 to OKT8 ratios. One patient had a high OKT4 to OKT8 ratio due to low number of OKT8-positive cells. Lymphocytes from patients showed normal proliferation after stimulation with T and B cell mitogens. In contrast, Ig synthesis by lymphocytes after stimulation with B cell mitogens was markedly deficient: low or undetectable levels of one or all classes of Ig were detected, whereas cell lines established from EBV-infected B lymphocytes from patients produced normal quantities of Ig. These studies imply immune regulatory impairments in the patient with XLP.
Biosynthesis and glycosylation of the invariant chain associated with HLA-DR antigens.
Authors: Machamer C E , Cresswell P 
Published: December 2022

Abstract
The biosynthesis and glycosylation of the invariant (I) chain associated with HLA-DR alpha-beta chain complexes has been examined in human B lymphoblastoid cell lines. Two-dimensional polyacrylamide gel electrophoresis of HLA-DR immune precipitates from extracts of metabolically labeled cells demonstrated a processes form of the I chain, called Ip, which consists of a series of spots beginning near the basic I chain spot and ending near the acidic alpha spots. Pulse/chase labeling yielded information on the kinetics of processing of the invariant chain, as well as the finding that the association of Ip with alpha-beta chain complexes appears to be transient. Neuraminidase treatment of immune precipitates confirmed that Ip was a form of the I chain containing up to eight sialic acid residues. Labeling in the presence of tunicamycin suggested the presence of both N-linked and O-linked oligosaccharide units on the invariant chain. This processing pattern does not appear to be an artifact of B cell lines; it was seen in peripheral blood lymphocytes, freshly purified monocytes, and in an interleukin 2-dependent continuous T cell line that expressed HLA-DR. In addition, there appears to be a free pool of the invariant chain and its processed form that is not found associated with DR alpha and beta chains.
Alloantisera detect HLA-A-B-C and non-HLA differentiation antigens on human thymocytes.
Authors: Mahoney R J , Gazit E , MacCarthy-Shanley K , Martin-Alosco S , Palomaki G E , Smith D E , Yunis E J 
Published: December 2022

Abstract
Human thymocytes (THY) were examined for the expression of HLA-A,B,C antigens on their cell surface by using tissue typing alloantisera in the microcytotoxicity assay. Approximately 80% of the total THY population demonstrated antibody-mediated, C-dependent lysis with several alloantisera for each HLA-A,B,C specificity. The HLA phenotype of THY was verified by HLA typing autologous peripheral blood lymphocytes (PBL) from the thymus donor. Thymus tissue and PBL were obtained from cardiac surgical patients ranging in age from 3 mo to 12 yr. The capacity of THY to absorb HLA alloantibody was also demonstrated. Cross-absorption studies performed on PBL and THY by using HLA typing sera produced two important findings: 1) HLA typing sera that are devoid of non-HLA THY-specific antibody can be used to HLA type THY and 2) selected non-HLA sera from multiparous women, and selected HLA typing sera absorbed with PRL or platelets can be used to detect THY differentiation antigens. Taken together, cytotoxicity data, absorption capacities, cross-absorption studies, and statistical analysis indicate that HLA-A,B,C alloantigens and non-HLA polymorphic differentiation antigens detected by alloantisera are co-expressed on the cell surface of the majority of human THY.
Augmentation of collagen arthritis by synthetic analogues of retinoic acid.
Authors: Trentham D E , Brinckerhoff C E 
Published: December 2022

Abstract
We evaluated the effect of administering orally two synthetic analogues of retinoic acid, 13-cis-retinoic acid and all-trans-N-(4-hydroxyphenyl)-retinamide to age-matched female Sprague-Dawley rats immunized with native chick type II collagen in incomplete Freund's adjuvant. Ingestion of a diet containing 13-cis-retinoic acid was associated with a significant increase in the severity of collagen arthritis, but there was no effect on weight gain or hemagglutinating antibody titers and delayed-type hypersensitivity to type II collagen. In two separate trials, ingestion of 4-hydroxyphenyl retinamide also significantly enhanced the severity of arthritis. Monolayer cultures of dissociated synovial cells taken from arthritic rats, but not nonarthritic rats, released prostaglandin E2 (PGE2) and collagenase into the medium. The level of PGE2 production was significantly decreased by in vivo or in vitro exposure to 4-hydroxyphenyl retinamide, whereas the addition of 13-cis-retinoic acid to the cultures had no effect on PGE2 release by the arthritic synovial cells. Five rats fed the 13-cis-retinoic acid-containing diet for 5 mo did not develop clinical or histologic evidence of arthritis. These data demonstrate that both retinoids possess potent enhancing properties for an experimentally inducible autoimmune arthritis, that synovial cells produce PGE2 and collagenase in this model, and that production of PGE2 can be suppressed by 4-hydroxyphenyl retinamide.
Celiac sprue: correlation with murine T cell responses to wheat gliadin components.
Authors: Kagnoff M F , Austin R K , Johnson H C , Bernardin J E , Dietler M D , Kasarda D D 
Published: December 2022

Abstract
Celiac sprue is a disease in humans that is characterized by small intestinal mucosal injury and malabsorption. Dietary exposure to gliadin and similar proteins in rye and barley activates the disease in susceptible individuals. Celiac sprue appears to be the only disease with a marked HLA-association in which the proteins that activate the disease currently are well known. However, bread wheat gliadins are a complex mixture of proteins that contain at least 40 different components. In the present study we have purified the major gliadin components of Scout 66 wheat and used these proteins to examine murine T cell proliferative responses to gliadin. Differences in T cell proliferation stimulated by alpha-, beta-, gamma-, and omega-gliadins paralleled the known structural differences among these proteins. After priming with whole gliadin, the components that stimulated T cell proliferation were the same as those recognized to activate celiac sprue in humans. Studies with reduced and alkylated A-gliadin (i.e., S-methyl A-gliadin) suggested that epitopes determined by the native conformation of A-gliadin may be important in its interaction with T cells. By using three different A-gliadin peptides that span the entire molecule, T cell proliferative responses were shown to be stimulated predominantly by antigenic determinants on the NH2-terminal peptide.