bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activation of the alternative complement pathway by isolated human glomerular basement membrane.
Authors: Williams J D , Czop J K , Abrahamson D R , Davies M , Austen K F 
Published: December 2022

Abstract
The capacity of isolated human glomerular basement membrane (GBM) to initiate surface activation of the human alternative complement pathway was defined by the deposition of C3b under circumstances in which the classical complement pathway was inoperative. The deposition of C3b from normal or C2-deficient serum was time- and magnesium-dependent, implying a role for the alternative pathway. Normal human serum rendered deficient in D did not sustain C3b deposition until its reconstitution with D, indicating an absolute requirement for a protein unique to the alternative pathway and essential to the cleavage activation of the C3 amplification convertase of that pathway. The capacity of the excess control proteins H and I to prevent C3b deposition onto GBM incubated in C2-deficient serum provided further evidence for the direct activation of the alternative pathway in this system. The use of radiolabeled monoclonal antibody to localize the deposited C3b afforded specificity and quantitation of about 100 ng of C3b/mg of GBM. Immunohistochemical analysis with a monoclonal antibody to detect C3b demonstrated its deposition to be confined to the epithelial surface of the GBM.
Genetic polymorphism of the sixth component (C6) of rat complement.
Authors: Granados J , Cramer D V , Caputo J B , Marcus D , Alper C A 
Published: December 2022

Abstract
The complement protein C6 has been shown to be genetically polymorphic in the rat. Isoelectric focusing of plasma samples from 19 inbred strains demonstrated two electrophoretically distinguishable migration patterns, each consisting of three bands. Breeding studies with the use of the BN and DA strains showed that the C6 patterns were inherited in a manner consistent with the co-dominant autosomal expression of two alleles (C6 A and C6 B). The distribution of the C6 alleles in a backcross mating was compared with eight independently segregating marker genes: RT1.A, RT2, Gdc -1, Igk-1, Hbb, Svp-1, Fh-1, and Es-6. There was no detectable linkage between C6 and any of these eight loci.
Amino acid and nucleotide sequences of variable regions of mouse immunoglobulin light chains of the lambda 3-subtype.
Authors: Reilly E B , Reilly R M , Breyer R M , Sauer R T , Eisen H N 
Published: December 2022

Abstract
To learn about the V lambda gene segments that are expressed in lambda 3 light chains, the most recently identified lambda-chain subtype in inbred mice, we determined partial amino acid sequences of the V regions of two of these chains, L5-8 and Lc49 . The partial sequences were extended by establishing the complete V region sequence of cDNA for the lambda-chain mRNA from the hybridoma (RZ 5-8) and the myeloma ( CBPC -49) that produce these chains. The primer extension method used to sequence the cDNA is described in detail, because the same primer (a synthetic heptadecadeoxynucleotide ) can be used for sequencing cDNA for lambda-chains of all three subtypes of inbred mice and probably for lambda-chains from some other vertebrate species as well. The results confirm earlier preliminary findings that for both chains the V region is encoded by the V lambda 1 and J lambda 3 gene segments. The unmutated germ-line sequences of these gene segments are present in both chains, but the two chains, nevertheless, differ at codon 97, the V lambda-J lambda boundary. A T/G difference in the third position of this codon resulted in a codon for histidine (CAT) in one chain (L5-8) and for glutamine (CAG) in the other chain ( Lc49 ). This difference can be accounted for by variation in the site of V lambda 1-J lambda 3 recombination. Though the V region amino acid sequences of L5-8 and Lc49 differ only by the His/Gln substitution at position 97, the two chains have been shown (manuscript in preparation) to differ in their ability to form an effective combining site for the 2,4-dinitrophenyl group.
Overproduction of immunoglobulin mRNA by a murine myeloma MOPC 315 variant cell line.
Authors: Ponte P A , Dean M , Pepe V H , Sonenshein G E 
Published: December 2022

Abstract
The mouse myeloma MOPC 315 cell line synthesizes and secretes IgA (lambda 2) immunoglobulin. A spontaneously arising variant of the MOPC 315 line, which had been isolated as apparently oversecreting IgA protein, has been characterized. The variant line has been shown to synthesize and secrete increased levels of heavy chain, light chain, and J chain polypeptide compared to the parental wild-type cells from which it was isolated. The steady-state levels of cytoplasmic mRNA for these polypeptides are increased commensurately in the over-producing line. For the heavy chain, enhanced transcription, and possibly increased gene dosage, appear to be involved. The increased levels of the three individual immunoglobulin polypeptide chains suggest that the variant line displays a coordinate regulation of expression of immunoglobulin genes.
Production and characterization of T cell clones specific for mouse hepatitis virus, strain JHM: in vivo and in vitro analysis.
Authors: Woodward J G , Matsushima G , Frelinger J A , Stohlman S A 
Published: December 2022

Abstract
Mouse hepatitis virus, strain JHM, is a coronavirus capable of inducing both acute and chronic central nervous system disease. To characterize the cell-mediated immune response directed toward JHMV antigens, we have generated and analyzed the properties of four T cell clones reactive to JHMV antigens. All four clones are of the Ly-1+2- phenotype and show an antigen-specific, I-Ab-restricted proliferative response that is dependent on antigen-presenting cells (APC). The fine specificity of I-A restriction was revealed by their differential recognition of JHMV antigen in the context of mutant I-A molecules present on B6.C-H-2bm12 APC. Two clones were unable to recognize JHMV antigen presented on bm12 APC, whereas a third clone showed an equivalent response with both bm12 and wild type B6 APC. In the analysis of the viral specificity, three of the clones showed distinct cross-reactions with MHV-2 and very little if any cross-reaction with MHV-A59. In addition, three of three clones tested responded well to sucrose gradient-purified, UV-inactivated JHMV, indicating that their specificity is directed toward virus structural rather than nonstructural proteins. Finally, two of the clones were analyzed for their ability to induce a DTH reaction when injected together with antigen into the footpads of various mouse strains. Consistent with the in vitro data, both clones produced a marked DTH response only in those strains carrying the I-Ab genotype. These data demonstrate, both in vivo and in vitro, that at least one component of the cell-mediated immune response to JHMV is characterized by an Ly-1+2-, I-A-restricted T cell specific for JHMV structural proteins.
Two new monoclonal antibodies (LN-1, LN-2) reactive in B5 formalin-fixed, paraffin-embedded tissues with follicular center and mantle zone human B lymphocytes and derived tumors.
Authors: Epstein A L , Marder R J , Winter J N , Fox R I 
Published: December 2022

Abstract
Two monoclonal antibodies (LN-1, LN-2) reactive with B lymphocytes in B5 formalin-fixed, paraffin-embedded tissue sections have been produced by utilizing cell extracts from pokeweed mitogen-stimulated peripheral blood lymphocytes and diffuse histiocytic lymphoma SU-DHL-4 cells, respectively. Both monoclonal antibodies were initially identified by indirect immunofluorescence screening techniques on paraformaldehyde-acetone-fixed cell preparations. Specificity screens with 36 well-characterized human lymphoma and leukemia cell lines showed that both LN-1 and LN-2 stained cell lines of B cell lineage but were unreactive with those of T cell or, with one exception, myeloid derivation. Null cell acute lymphoblastic leukemia cell lines were found to be LN-2+ but LN-1-. The B cell specificity of these reagents was confirmed on 15 lymphoma and 17 leukemia biopsy specimens by using indirect immunofluorescence techniques. Immunoperoxidase staining of sections from B5-fixed, paraffin-embedded human lymphoid tissues showed that LN-1 bound to the cell membrane and cytoplasm of germinal center cells whereas LN-2 stained the nuclear membrane and cytoplasm of germinal center and mantle zone B lymphocytes as well as interfollicular histiocytes and thymic medullary dendritic cells. Both monoclonal antibodies failed to stain cortical thymocytes, lymph node T cells, and peripheral blood T and myeloid cells. Immunoperoxidase staining of 20 nonlymphoid human organs and tissues revealed that LN-1 reacted positively with red blood cell precursors of the bone marrow, ciliated epithelial cells of the bronchus, distal tubular cells of the kidney, and ductal cells from several organs including the breast and prostate. In contrast, LN-2 was unreactive with all human nonlymphoid organs and tissues including the bone marrow. Indirect immunofluorescence staining of a panel of 26 solid tumor cells lines showed that LN-1 was reactive with the majority of epithelium-derived cell lines, glioblastomas, and astrocytomas but was unreactive with neuroblastomas, small cell carcinoma of the lung, and sarcomas. LN-2 was unreactive with 25 of 26 of the solid tumor cell lines by these techniques. Immunobiochemical studies have shown that LN-1 recognizes a cell surface sialoantigen whereas LN-2 is directed against a 35,000 dalton nuclear membrane protein. Because of their high specificity for B cell tumors and their ability to stain B5-fixed, paraffin-embedded tissues, LN-1 and LN-2 are useful reagents for the diagnosis and classification of the human lymphomas and leukemias.
Description of a murine B lymphoma tumor-specific antigen.
Authors: Koch S , Zalcberg J R , McKenzie I F 
Published: December 2022

Abstract
By using monoclonal antibodies, a tumor-specific antigen (TSA 41.5) was detected on the cell surface of a B lymphoma CH-1 tumor variant, CH-1.1. This antigen is not expressed by normal lymphocytes (spleen cells, lymph node cells, thymocytes, bone marrow cells, or blast cells) of B10.A mice, the host strain of CH-1.1, or by the CH-1 lymphoma. Immunoprecipitation and biochemical characterization of TSA 41.5 with the use of two-dimensional gel electrophoresis showed this antigen to be a surface protein of CH-1.1 cells with an Mr of 80k and pI of 4.6. TSA 41.5 is not related to the murine transferrin receptor, and not to gp70, a viral envelope protein expressed by CH-1.1 cells, shown by comparative peptide map analysis of these three proteins. TSA 41.5 is a surface antigen unique to the CH-1.1 tumor, which is not expressed by the 19 different murine tumor lines that were tested nor by spleen cells of 15 independent mouse strains. In addition, treatment of spleen cells with bacterial lipopolysaccharide did not induce the expression of TSA 41.5. These characteristics of TSA 41.5 make it unlikely to be a product of viruses. Additional evidence against TSA 41.5 being a viral protein was obtained by the observation that antisera against viral proteins could not block the binding of the anti-TSA monoclonal antibody to its antigen. In vitro treatment of CH-1.1 cells with anti-TSA monoclonal antibody specifically inhibited the in vitro growth of the tumor cells in a dose-dependent fashion. The CH-1.1 tumor and monoclonal antibodies could be a useful murine model system for the exploration of the use of monoclonal antibodies for the in vivo treatment of cancer.
Modulation of polyclonally activated human peripheral B cells by aggregated IgG and by IgG-binding factors: differential effect on IgG subclass synthesis.
Authors: Bich-Thuy L T , Revillard J P 
Published: December 2022

Abstract
The regulation of IgG subclass production by polyclonally activated human B cells was investigated by using two systems previously shown to selectively suppress the generation of IgG-containing cells (CC) but not that of IgMCC or IgACC. The first one involved a brief exposure of peripheral blood mononuclear cells (PBMNC) to heat-aggregated human IgG (Agg-IgG) followed by repeated washings and culture with untreated autologous PBMNC. The second one was achieved by addition of human IgG-binding factor(s) (IgGBF) prepared by affinity chromatography from supernatants of unstimulated PBMNC. Pokeweed mitogen (PWM) and Nocardia opaca delipidated cell mitogen (NDCM) were used as polyclonal B cell activators. The latter can induce the terminal differentiation of peripheral B lymphocytes into plasma cells in the absence of helper T cells. After 6 days of culture, the number of cells containing IgM, IgG, or IgA was determined by direct immunofluorescence, and that of cells containing IgG1, IgG2, IgG3, or IgG4 was determined by indirect immunofluorescence with the use of subclass-specific monoclonal antibodies. After stimulation with PWM, exposure of PBMNC to Agg-IgG resulted in a selective diminution of the number of IgG4CC. With NDCM-stimulated cultures the same procedure induced a selective suppression of the generation of IgG2CC and IgG4CC. Conversely, the addition of IgGBF at the third day of culture was found to induce a 30 to 40% decrease in the number of cells containing each of the four IgG subclasses. Because of their differential pattern of IgG subclass suppression, Agg-IgG and IgGBF are likely to trigger distinct regulatory pathways.
Supplemental zinc restores antibody formation in cultures of aged spleen cells.
Authors: Winchurch R A , Thomas D J , Adler W H , Lindsay T J 
Published: December 2022

Abstract
The in vitro production of antibody to T-dependent antigens is depressed as a function of age. The addition of supplemental zinc to cultures of cells from young adult, middle-aged, and immunodepressed-aged mice enhances antibody production. The responses of young mice are enhanced 30 to 40%, but the responses in cultures from aged mice are increased 5- to 12-fold and the maximum response achieved is often equivalent to that of young, fully competent mice. The addition of zinc at varying times during the culture period suggests that zinc affects early events in the activation of antibody-forming cells.
B cell activation. V. Differentiation signaling of B cell membrane depolarization, increased I-A expression, G0 to G1 transition, and thymidine uptake by anti-IgM and anti-IgD antibodies.
Authors: Cambier J C , Monroe J G 
Published: December 2022

Abstract
Although studies have suggested that B cell membrane-associated IgM and IgD may function differently in the generation of humoral immune responses, this difference has proven difficult to define precisely. Toward a better understanding of the function of these antigen receptors, we compared the ability of F(ab')2 fragments of antibodies specific for mouse Fab, IgM, and IgD to induce early changes in B cell physiology that are indicative of cell activation. Specifically, we assessed the ability of membrane IgM (mIgM) or membrane IgD (mIgD) or both in combination to transduce signals that result in membrane depolarization, increased I-A expression, G0 to G1 transition, and thymidine uptake. Results indicate that at low levels of anti-receptor antibody (0.01 to 0.1 microgram/ml) both isotypes transduce signals for the induction of membrane depolarization and increased I-A expression by a significant proportion of B cells, i.e., Ig+ cells. Higher concentrations of ligand (5 to 25 micrograms/ml) are required to induce a significant proportion of cells to undergo G0 to G1 transition and increase thymidine uptake. At optimal concentrations, anti-IgM and anti-IgD induce membrane depolarization and increased I-A expression by 80 to 90% of B cells. Although mIgM also transduces signals sufficient for G0 to G1 transition by 80 to 90% of B cells, mIgD transduces signals sufficient for G0 to G1 by only about 40% of B cells. A similar difference exists for the induction of thymidine uptake. Thus, results suggest that membrane Ig may transduce two different signals depending upon the amount of ligand that they bind. Although in some B cells mIgD can transduce both signals resulting in membrane depolarization and progression into G1, in most cells mIgD transduces only the first signal, resulting in membrane depolarization and increased I-A expression.
Recognition and response to alloantigens in vivo. I. Negative and positive selection of MLR reactivity in murine peripheral blood lymphocytes to major histocompatibility complex and Mls antigens.
Authors: Ryan J J , Ahmed A , Kind P D , Thompson C B , Berning A K , Sell K W 
Published: December 2022

Abstract
Specific mixed lymphocyte reaction (MLR) responsiveness to allogeneic major histocompatibility complex (MHC), or minor lymphocyte-stimulating (Mls) determinants, was depleted in the peripheral blood lymphocytes (PBL) obtained from mice 24 to 48 hr after i.v. injection of 5 to 7.5 X 10(7) MHC or Mlsa-incompatible spleen cells, respectively. Results of cell mixture experiments suggest that the generation of suppressor cells was not the explanation for this specific reduction in MLR proliferation occurring with these PBL responder cells. To gain additional insight into parameters involved in the recognition of allodeterminants in vivo, experimental manipulations of the host environment and donor cell inoculum utilized in the negative selection procedure were employed. For example, removal of the spleen in the recipient animal, an anatomic site in which injected allogeneic cells and corresponding host antigen-reactive cells (ARC) are trapped, still permitted the specific depletion in murine PBL of host ARC for donor foreign MHC antigens. This finding may implicate other sites such as the liver where unprimed host alloreactive clones are trapped. In addition, irradiation of allogeneic donor cells significantly reduced their capacity to trap alloreactive T cell clones in vivo, whereas heat treatment of the donor cells completely eliminated this ability, even though the Ia determinants were still expressed, measured by flow cytometry. After the negative selection period, kinetic analysis of proliferation showed that 3, 4, or 5 days after injection of MHC-incompatible allogeneic spleen cells, the PBL of the recipient showed specific hyperresponsiveness to the MHC-haplotype of the donor cells. Interestingly, these primed PBL responder cells had the volume distribution of small resting cells; thoracic duct lymphocytes (TDL), positively selected by adoptive transfer of T cells to irradiated semiallogeneic recipients, are reported to be mainly blast cells. In contrast to the MLR hyperresponsiveness that results from priming with MHC-incompatible splenocytes, PBL, obtained at these later time points from mice primed with Mlsa-incompatible, H-2-compatible splenocytes, showed complete unresponsiveness in MLR to these Mlsa-bearing stimulator cells, as well as some nonspecific reduction in proliferation to MHC-incompatible stimulator cells regardless of their Mls genotype.(ABSTRACT TRUNCATED AT 400 WORDS)
Establishment of three PPD-reactive helper T cell clones with distinct functions in B cell activation.
Authors: Sano Y , Yamada G , Dobashi K , Mizuochi T , Hamaoka T , Takatsu K 
Published: December 2022

Abstract
Three PPD-reactive long-term cultured helper T cell clones were established from Mycobacterium tuberculosis (Tbc)-primed spleen cells. Clones B11.15 and B12.F were derived from C57BL/6 mice, and clone D-2 was originated from DBA/2Ha mice that have an X-linked recessive inheritance of T cell-replacing factor (TRF) unresponsiveness. Proliferative responses of these cloned T cells were induced by stimulation with PPD in a dose-dependent manner only when I-A-subregion compatible antigen-presenting cells (APC) were present. These three T cell clones have distinct helper functions in B cell activation. Clone B11.15 activated DNP-primed B cells to induce anti-DNP IgM plaque-forming cell (PFC) responses only when high amounts of PPD (5 micrograms) were added to the culture in a major histocompatibility complex (MHC)-unrestricted manner (factor-mediated interaction), whereas stimulation with a low amount of DNP-PPD (0.05 microgram) was ineffective. On the other hand, clone D-2 triggered B cells in the presence of a low amount of DNP-PPD in a MHC-restricted manner (cognate interaction). Significant helper activity of D-2, however, was not observed in the presence of high amounts of PPD. Clone B12.F was able to activate B cells in the presence of either DNP-PPD or PPD. Moreover, both B11.15 and B12.F produced helper factor(s) such as TRF by stimulation with high amounts of PPD in the presence of syngeneic APC, whereas D-2 did not produce measurable helper factor(s) under the same conditions. These results suggest that at least three distinctly functioning PPD-reactive helper T cells can be generated by active immunization with Tbc in vivo. T-B cell interaction between distinctly functioning T cell clones and B cells from (DBA/Ha X C57BL/6) (DB6)F1 male or female mice was then examined. B cells from DB6F1 female mice were triggered by both B11.15 and B12.F in a factor-mediated manner and were also activated with B12.F or D-2 in cognate manner. On the other hand, B cells from DB6F1 male mice, which are TRF low responders, were activated by B12.F or D-2 only through cognate interaction, and they failed to cooperate with B12.F or B11.15 in factor-mediated manner. These findings further suggest that B cells can be triggered by at least two distinct helper T cell subpopulations via respective pathways (cognate interaction and factor-mediated interaction).(ABSTRACT TRUNCATED AT 400 WORDS)
Antigen-reactive cloned helper T cells. II. Exposure of murine cloned helper T cells to IL 2-containing supernatant induces unresponsiveness to antigenic restimulation and inhibits lymphokine production after antigenic stimulation.
Authors: Wilde D B , Prystowsky M B , Ely J M , Vogel S N , Dialynas D P , Fitch F W 
Published: December 2022

Abstract
Cloned murine helper T lymphocytes (HTL) reactive to alloantigen or to ovalbumin (OVA) become unresponsive to antigenic restimulation after exposure to antigen or to culture supernatant fluids (SF) containing multiple lymphokine activities. Unresponsiveness is manifest by a failure of antigen-stimulated cells to incorporate thymidine or to produce lymphokines after antigenic challenge. Antigen-unresponsive HTL, however, will incorporate thymidine when exposed to an exogenous source of interleukin 2 (IL 2). The duration of unresponsiveness to antigen is correlated with the concentration of IL 2 in SF to which the cloned HTL had been exposed. Chromatographic fractionation of IL 2-containing supernatant from EL-4 thymoma cells (EL-4 SF) yielded a pool of SF that was enriched for IL 2 activity. Exposure of HTL to lymphokines contained in this pool induced unresponsiveness to antigen that was comparable to that observed when HTL were exposed to unfractionated EL-4 SF. Unresponsiveness to antigen also developed after cloned HTL were stimulated with concanavalin A (Con A) or with OVA and syngeneic splenic filler cells. We have used monoclonal antibody (mAb) GK1.5 (anti-L3T4) to investigate the role of lymphokine production in the induction of unresponsiveness. This antibody did not inhibit IL 2-induced thymidine incorporation by cloned HTL, and did not inhibit the induction of unresponsiveness after exposure of cloned HTL to EL-4 SF. In the presence of mAb GK1.5, however, HTL that were stimulated with Con A or OVA did not become unresponsive to antigenic restimulation, an effect that was overcome by the addition of EL-4 SF. These results suggest that HTL become unresponsive to antigen after exposure to IL 2-containing SF, and that stimulation by antigen or Con A can induce the unresponsive state by virtue of stimulating lymphokine production.