bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclosporin A does not prevent expression of Tac antigen, a probable TCGF receptor molecule, on mitogen-stimulated human T cells.
Authors: Miyawaki T , Yachie A , Ohzeki S , Nagaoki T , Taniguchi N 
Published: December 2022

Abstract
Results of recent studies indicated that a monoclonal anti-Tac antibody might recognize the receptor sites or closely related structures for T cell growth factor (TCGF) on activated human T cells. In the present study, we examined the effect of cyclosporin A (CsA) on the expression of Tac antigen by mitogen-stimulated T cells. CsA inhibited the proliferative response of T cells to Con A and PHA in a dose-dependent manner. Both Con A- and PHA-induced cellular proliferation were decreased to about 10% of controls at 5 micrograms/ml of CsA. When T cells were stimulated with these mitogens, many of them expressed Tac antigen on their surfaces, assessed by the immunoperoxidase method. The appearance of Tac-positive cells occurred earlier than a rise of cellular DNA synthesis. Characteristically, CsA showed no inhibitory effect on the expression of Tac antigen by mitogen-stimulated T cells, even at a relatively high concentration of 5 micrograms/ml, whereas the expression of other "activation" antigens reactive with monoclonal anti-Ia, OKT9, or OKT10 antibodies by T cells was blocked completely by CsA. Morphologically, the majority of Tac-positive cells in culture with mitogens alone showed the characteristics of blastoid cells; Tac-positive cells in the culture containing CsA mainly consisted of medium-sized cells, indicating these cells probably accumulated at a stage of partial activation. T cells, once stimulated with Con A or PHA for 3 days whether in the presence or in the absence of CsA, were able to absorb TCGF activity from TCGF-containing media similarly. In addition, T cells, even stimulated in the presence of CsA with these mitogens for 24 hr, were capable of responding to TCGF with the same grade of proliferation as did T cells stimulated with mitogen alone. CsA showed no appreciable inhibition in a TCGF-dependent proliferation of such prestimulated cells. These functional properties of activated T cells might be correlated with their ability to express Tac antigen. These experimental findings present some evidence that CsA might not prevent the expression of probable functional receptor sites for TCGF in mitogen-dependent activation of human T cells.
Regulation of the growth and differentiation of a human monocytic cell line by lymphokines. I. Induction of superoxide anion production and chemiluminescence.
Authors: Clement L T , Lehmeyer J E 
Published: December 2022

Abstract
The U937 human monocytic cell line was studied to determine its ability to generate a respiratory burst after stimulation with phorbol myristate acetate (PMA) or opsonized zymosan. U937 cells cultured in normal medium produced virtually no superoxide anion or chemiluminescence in response to either stimulus. In contrast, U937 cells cultured in medium containing soluble factors from activated lymphocytes produced significant O2- and chemiluminescence when stimulated with PMA or opsonized zymosan. The chemiluminescence in response to PMA was maximal in U937 cells precultured with these soluble factors for 3 days, whereas maximal responsiveness to opsonized zymosan was not observed until 5 to 6 days of lymphokine exposure. Although this ability to generate a respiratory burst persisted for a number of days in U937 cells that were subsequently recultured in normal medium, this responsiveness was gradually lost in the continued absence of these factors. The data indicate that the U937 monocytic cell line can be activated or induced to differentiate by soluble factors released by activated lymphocytes. In the process, these cells acquire the ability to generate a respiratory burst. The U937 cell line may serve as a useful model for the study of the ontogeny and regulation of the respiratory burst during human monocytic differentiation.
Molecular and antigenic nature of isolated Sm.
Authors: Dang H , Fischbach M , Lerner E , Talal N 
Published: December 2022

Abstract
The Sm antigen was isolated and purified from calf thymus nuclear extract by affinity chromatography. The affinity columns were made with serum antibodies from an SLE patient or an anti-Sm monoclonal antibody derived from a hybridoma cell line. Proteins eluted from these two columns had m.w. of 58,000 and 35,000 by SDS polyacrylamide gel electrophoresis. The natural conformation of this antigen appears to be 95,000 in m.w. with the 58,000 particle containing the Sm antigenic determinant. The affinity column-purified antigen detected by the human anti-Sm antibodies is also recognized by anti-Sm antibodies in murine lupus serum, as shown by solid-phase radioimmunoassay. This study 1) demonstrates the molecular and antigenic nature of the Sm antigen and 2) compares the anti-Sm binding capabilities of antibody populations present in sera from SLE patients and from MRL lpr/lpr mice.
Characterization of monoclonal antibodies that define rat T cell alloantigens.
Authors: Ely J M , Greiner D L , Lubaroff D M , Fitch F W 
Published: December 2022

Abstract
A panel of monoclonal antibodies with specificity for rat T cell alloantigens was prepared by somatic cell hybridization with the use of spleen cells from either BH (ART-1b, 2b) or NBR (ART-1b, 2a) rats immunized with LEW (ART-1a, 2a) thymus, spleen, or lymph node cells. Comparison of the antibodies resulted in three distinct patterns of complement-mediated cytotoxicity. Further comparison of four representative hybridoma antibodies with antisera having specificity for ART antigens by indirect immunofluorescence demonstrated that two of the three patterns corresponded to anti-ART-1a and anti-ART-2a specificities. The patterns of binding of the anti-ART hybridomas were shown to be different from those produced by mouse monoclonal antibodies having anti-leukocyte-common (L-C) or anti-Thy-1.1 activities as well as antibodies produced by the monoclonal W3/25, which detect a subpopulation of T lymphocytes. Functional studies performed in vitro with cells fractionated by treatment with the monoclonal anti-ART antibodies and complement showed the ART-1 determinant recognized by the hybridoma products BC 84A or BY 12.3 is expressed by mature cytolytic T lymphocytes (CTL) and by cells involved in the generation of CTL during MLR, but not plaque-forming cells. Together, the data suggest the antibodies BC 84A and BY 12.3 can be used to define rat T cell populations. To date, the functional significance of cell populations recognized by monoclonal antibodies having anti-ART-2a or anti-ART-3-like activities has not been determined.
Stimulation of prostaglandin E and thromboxane synthesis in macrophages by purified C3b.
Authors: Hartung H P , Hadding U , Bitter-Suermann D , Gemsa D 
Published: December 2022

Abstract
Complement cleavage product C3b was examined for its effect on macrophages. Albumin-elicited guinea pig peritoneal macrophages kept in short-term culture were challenged with purified homologous C3b, and release of oxygen and arachidonic acid metabolites was studied. C3b at concentrations ranging from 20 to 80 micrograms/ml induced synthesis of large quantities of the arachidonic acid cyclooxygenation products thromboxane B2 (TXB2) and prostaglandin E (PGE) but failed to trigger an oxidative burst. Our findings link together macrophages, complement, and arachidonate metabolites as major participants in inflammatory responses.
Lymphocyte function in experimental African trypanosomiasis. VI. Parasite-specific immunosuppression.
Authors: Dempsey W L , Mansfield J M 
Published: December 2022

Abstract
The ability of mice infected with African trypanosomes to produce antibodies to the surface antigen of the infecting trypanosome variant antigenic type upon primary and secondary exposure was examined. C57BL/10SnJ mice were infected initially with Trypanosoma rhodesiense clone LouTat 1.0. Surface antigen-specific antibody titers (IgM and IgG) to the infecting variant were measured throughout the course of infection; when the titers were sufficiently low, mice were reinfected with LouTat 1.0 trypanosomes and the antibody response was measured. Results demonstrate that mice in the early stage of infection exhibited transient suppression of antibody responses to LouTat 1.0 upon reexposure. In contrast, mice in the terminal phase of the disease were completely suppressed in their ability to mount a humoral response to LouTat 1.0. Trypanocidal chemotherapy of mice restored immunoresponsiveness in that treated mice responded with both IgM and IgG surface antigen-specific antibody to LouTat 1.0. The resulting antibody response, however, was more indicative of a primary humoral response to the parasites rather than a true secondary immune response.
Immunochemical structure of hepatitis B e antigen in the serum.
Authors: Takahashi K , Machida A , Funatsu G , Nomura M , Usuda S , Aoyagi S , Tachibana K , Miyamoto H , Imai M , Nakamura T , Miyakawa Y , Mayumi M 
Published: December 2022

Abstract
Hepatitis B e antigen (HBeAg) constitutes the nucleocapsid of hepatitis B virus (HBV) and occurs in association with plasma proteins, particularly with IgG, in the serum of persons infected with the virus. A polypeptide with an approximate m.w. of 15,500 (P15.5) is obtained either from HBeAg in the serum or from the nucleocapsid of HBV. P15.5 preparations from serum and virus resembled closely each other in the amino acid composition. The C-terminus amino acid sequence of P15.5 from serum was determined to be -Thr-Thr-Val-Val, whereas that from the virus ended with -Thr-Thr. The same sequence of four amino acid residues was found on the gene coding for the nucleopeptide of hepatitis B virus with a molecular size of 19,000 daltons (P19). P15.5 identified on the nucleotide sequence of P19 was composed of 149 amino acid residues with a calculated molecular size of 16,770 daltons. The gene coding for P19 had two -Asp-Pro-connections. By splitting these connections in P19 and P15.5 preparations with formic acid, smaller polypeptides were obtained with sizes predicted from the nucleotide sequence and with the N-terminus amino acid of proline as expected. One of two monoclonal antibodies raised against the core of Dane particles (HBcAg) bound with P15.5 preparations purified from serum and HBV. The IgG fraction from a human serum containing antibodies to HBcAg but not to HBeAg bound with P15.5 also. On the basis of the results obtained, the IgG molecules associated with P15.5 in the serum of persons infected with HBV may well represent the antibodies against HBcAg with limited specificities.
Recovery from a viral respiratory tract infection. IV. Specificity of protection by cytotoxic T lymphocytes.
Authors: Wells M A , Daniel S , Djeu J Y , Kiley S C , Ennis F A 
Published: December 2022

Abstract
Immune spleen cells enhanced for influenza-specific cytotoxic activity after exposure to virus-infected stimulator cells in vitro effect recovery when transferred to nude and immunocompetent mice with influenza pneumonia (5). This protective effect correlated with the virus-specific cytotoxic activity of the transferred lymphocytes and is removed by treatment with anti-0 serum and complement. The experiments presented here indicate that spleen cells taken directly from mice undergoing a primary or secondary infection are less protective than immune spleen cells that are restimulated in vitro before transfer. This decreased ability to clear pulmonary virus and effect survival correlated with their relatively lower levels of influenza-specific cytotoxicity. Protection did not correlate with the level of natural killer cell activity of transferred cells. The results also indicate the immune spleen cells that are protective are influenza A subtype cross-reactive and are H-2-restricted; H-2d immune spleen cells effected recovery of H-2d but not H-2k challenged mice.
Influence of Igh-C- and MHC-linked genes on the activity of immunoglobulin-recognizing T cells.
Authors: Bikoff E , Bona C A 
Published: December 2022

Abstract
BALB/c Lyt-1+ cells that proliferate in response to NP-modified BALB/c Ig fail to respond to BALB/c Ig modified by a different hapten, TNP. By contrast, when NP-modified BALB/c Ig is used as the immunogen in C.B-20 mice, a strain congenic with BALB/c but expressing the Ighb allotype of C57BL/6 (B6), a partial cross-reaction between NP- and TNP-BALB/c Ig is observed. Similarly, strains expressing different Igh haplotypes also show distinct reactivities toward NP-B6 Ig and NP-modified myeloma proteins. Thus, the proliferative response to NP-modified Ig is regulated by Igh-linked genes. In this paper, we also characterize the T cell proliferative response to IgG2a of the b allotype. We show that allotypic determinants on this molecule are recognized in association with self MHC-encoded gene products and that responsiveness is controlled by MHC-linked Ir genes. Thus, products of MHC-linked genes also influence the activity of Ig-recognizing T cells. Taken together, experiments described in this report suggest that T cells directed against immunogenic determinants on antibody molecules are governed by the same rules as T cells that respond to conventional antigens.
The cell surface phenotype of a naturally occurring human suppressor T-cell of restricted specificity: definition by monoclonal antibodies.
Authors: Brankovan V , Bean M A , Martin P J , Hansen J A , Sadamoto K , Takahashi Y , Akiyama M 
Published: December 2022

Abstract
A series of murine monoclonal antibodies was used to characterize the surface phenotype of a naturally occurring E+ B14-specific suppressor cell present in the blood of a patient with recurrent superficial bladder carcinomas. This suppressor T cell is different from the few naturally occurring suppressors of MLC reported by others in that its function does not require HLA-D compatibility with the cells being suppressed. This patient's T cells had decreased proportions of T3+, 10.2+, 9.3+, and T4+ cells, a normal proportion of T8+ cells, and a markedly increased proportion of Ia-positive cells. The MLC-suppressor assay was used to test the functional activity of cell populations selectively depleted by treatment with monoclonal antibodies and C or enriched by panning. The B14-specific suppressor T cells in this patient expressed T cell markers recognized by monoclonal antibodies 9.6, T3, and the T cell subset marker identified by OKT8 (T8+) but not the subset marker identified by OKT4 (T4-). Ia antigens were present on a substantial portion of these suppressor T cells. Thus, this unique, naturally occurring suppressor T cell has a phenotype similar to that of other T suppressor cells in humans, adding validity to the concept of functionally distinct T cell compartments in human blood.
Induction of phenotypic differentiation, interleukin 2 production, and PHA responsiveness of "immature" human thymocytes by interleukin 1 and phorbol ester.
Authors: de Vries J E , Vyth-Dreese F A , Figdor C G , Spits H , Leemans J M , Bont W S 
Published: December 2022

Abstract
Small human thymocytes (ST) representing 70% of the thymocytes were isolated according to size by centrifugal elutriation. Although these ST contained approximately 30% PNA-cells, they failed to respond to lectins, indicating the existence of a PNA-ST subset that can be considered to belong to the "immature" thymocyte population. The ST were induced to proliferate if, in addition to PHA, IL 1-containing supernatants of highly purified monocyte cultures or 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were present. The incubation of the ST for 90 hr with TPA or IL 1 in the absence of PHA resulted in a strong reduction in the percentage of cells reacting with the immature thymocyte markers TdT and PNA. In addition, the OKT6+ cells were partially reduced after incubation with IL 1. Concomitantly, an increase in the percentage of cells reacting with the mature T cell markers OKT1 and OKT3 was observed, whereas HLA antigens became strongly expressed on all ST. Although IL 1 or TPA were unable to induce proliferation of the ST, these substances induced IL 2 production by these cells. These shifts to cells with more "mature" phenotypes that are able to produce IL 2 were not observed if the ST were incubated with PHA or culture medium only. The responder capacity of the ST to PHA plus TPA was not significantly affected by the depletion of the more "mature" OKT3+ and OKT1+ cells. In addition, in this situation OKT1+, OKT3+, OKT6- cells were found to be generated from OKT1-, OKT3-, OKT6+ cells. Therefore, it could be excluded that the proliferative responses were due to a selective expansion of a preexisting mature T cell population. Our results indicate that TPA mimics IL 1 in the induction of differentiation of the ST to a stage in which subpopulations of these cells are able to produce IL 2 and to respond to PHA. Because only the proliferating ST were found to react with a monoclonal antibody, which is thought to be directed at the IL 2 receptor (anti-Tac), our data suggest that PHA is required for the induction of expression of receptors for IL 2 in those ST subpopulations that are able to proliferate in the presence of IL 2 generated in situ.
Distinction of two subtypes of human leukocyte interferon (IFN-alpha) on B cell activation. B cell proliferation by two subtypes of IFN-alpha.
Authors: Harada H , Shioiri-Nakano K , Mayumi M , Kawai T 
Published: December 2022

Abstract
We examined the effect of interferon (IFN), with particular emphasis on the effects of the two subtypes of IFN-alpha (IFN-alpha A and IFN-alpha B) on the B cell proliferation induced by Staphylococcus aureus Cowan I bacterium (SpA Col). An increase of SpA Col-induced proliferation was observed in the presence of 100 to 1000 U/ml of IFN-alpha, but a decrease of SpA Col-induced proliferation was observed in the presence of 1000 to 10,000 U/ml of IFN-beta. The two subtypes of IFN-alpha had different effects on cell proliferation; a significant enhancement was shown in the presence of 1000 to 10,000 U/ml of IFN-alpha A, but inhibition was shown in the presence of 1000 to 10,000 U/ml of IFN-alpha B. In the reconstitution test of the two subtypes of IFN-alpha, the boundary between enhancement and inhibition of SpA Col-induced proliferation was revealed when the proportion of IFN-alpha A and IFN-alpha B (IFN-alpha A:IFN-alpha B) ranged between 8:2 and 9:1. Toward the SpA Col-induced responses, the above IFN were all found to act on B cells directly, independent of the presence of T cells. Proliferative responses by IFN-alpha and IFN-alpha A, however, were shown to be slightly dependent on the presence of monocytes. The lymphocyte proliferation induced by other mitogens (phytohemagglutinin, concanavalin A, pokeweed mitogen, and protein A of S. aureus) were all inhibited by the above IFN.
The interaction of C3b bound to pneumococci with factor H (beta 1H globulin), factor I (C3b/C4b inactivator), and properdin factor B of the human complement system.
Authors: Brown E J , Joiner K A , Gaither T A , Hammer C H , Frank M M 
Published: December 2022

Abstract
Pneumococcal cell walls are potent activators of the alternative complement (C) pathway; pneumococcal capsules are not. C3b that is deposited onto the cell walls of encapsulated organisms, however, functions inefficiently in host defense compared to C3b deposited onto capsular polysaccharides. Results of previous studies with guinea pig erythrocytes suggested that C3b deposited onto surfaces that do not activate the alternative pathway is rapidly inactivated. In the present study, we examined the interactions of C3b bound to pneumococcal capsules, to pneumococcal cell walls, and to the surface of sheep erythrocytes (E) with the serum control proteins, Factor H (beta 1H globulin) (H) and Factor I (C3b/4b inactivator) (I), and with Factor B (B) of the alternative C pathway. Conversion of bound C3b to C3bi was assayed by binding of radiolabeled conglutinin in a quantitative binding assay. Neither pneumococcal cell wall C3b nor capsular C3b was converted efficiently to a conglutinin-binding form by serum incubation. Experiments with purified C components showed that, after incubation with H and I, fewer conglutinin-binding sites were created on pneumococci than on E bearing equal numbers of C3b. Molecular analysis demonstrated that this did not result from cleavage of pneumococcal-bound C3b to an unusual, nonconglutinin-binding form of the molecule. Binding studies in which radiolabeled H was used demonstrated that the majority of C3b that is bound to both pneumococcal capsules and cell walls bound H with a lower affinity than did E-bound C3b. Studies of the binding of radiolabeled B demonstrated that C3b that was bound to pneumococcal cell walls and to E demonstrated equal affinity for B. In contrast, the majority of C3b that was fixed to pneumococcal capsules bound B with only 1/30 as high affinity. We conclude that pneumococcal capsules are not alternative pathway activators because the low affinity of capsular C3b for B leads to inefficient formation of an alternative pathway convertase, C3bBb. With regard to H binding, both cell wall- and capsular-bound C3b act as if they were in a "protected site" and resist degradation by the control proteins.
Induction of granulocyte histaminase release by particle-bound complement C3 cleavage products (C3b, C3bi) and IgG.
Authors: Melamed J , Medicus R G , Arnaout M A , Colten H R 
Published: December 2022

Abstract
The interaction of opsonized particles with human granulocytes promotes a number of important biologic functions, including phagocytosis, superoxide generation, and release of a variety of enzymes, including histaminase. We have previously determined that histaminase release occurs via a C3-dependent process. Although fluid-phase C3b dimers can mediate release, the relative effects of particle-bound C3b and C3bi and of IgG have not been examined. In this report we demonstrate that particle-bound C3 deposited on activators of the alternative C pathway effected histaminase release in the absence of IgG. Particle-bound C3bi and C3b were both effective as mediators of histaminase release. The extent of release varied as a function of the activating surface on which C3 was deposited (zymosan C3b was considerably more potent than C3b bound to rabbit erythrocytes, which was slightly more potent than C3b bound to neuraminidase-treated sheep erythrocytes). In contrast, C3b or C3bi deposited on nonactivating surfaces (such as sheep erythrocytes) at inputs of up to 2,000,000 molecules per granulocyte failed to induce histaminase release unless IgG was also present. The ability of C3b bound to particles that serve as activators of the alternative pathway to induce histaminase release is apparently not the result of decreased susceptibility of C3b to proteolysis or to an increased binding affinity to the C3b receptor, but may relate to the interaction of other surface structures on activating particles with the PMN membrane.