bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency of herpes simplex virus-specific helper T lymphocyte precursors in the lymph node cells of infected mice.
Authors: Prymowicz D , Moore R N , Rouse B T
Published: December 2022

We have established a limited dilution assay to estimate the frequency of herpes simplex virus type 1 (HSV)-specific, interleukin 2 (IL 2)-producing helper T lymphocyte precursors (HTL-P). The estimated frequency of such cells in suspensions of local lymph node (LN) cells 5 days after in vivo virus infection was 1:2470 to 1:5800. Frequencies of HTL-P in cells from uninfected mice were below levels of detection of our system and were judged to be below 1:100,000. Removal of Lyt-2+ cells from responder LN cells before culture increases HTL-P frequency twofold to threefold, indicating the likely operation of some form of suppression in unseparated cultures. The demonstration of HSV-specific HTL-P required that cells from virus-primed mice be reexposed in vitro to viral antigen. In addition, clones expanded during a 9-day culture period failed to generate IL 2 unless reexposed to specific viral antigen or cross-reactivate HSV-2. Thus, HSV-specific HTL-P were strictly antigen dependent. No evidence was obtained for antigen-independent subpopulations of HTL-P as occurs with viral-specific cytotoxic T lymphocyte precursors. The clonal progeny of HTL-P were of the Thy-1+ Lyt+2- phenotype. Priming in vivo for the subsequent in vitro detection of HTL-P required that mice be exposed to infectious virus. Thus neither UV-inactivated nor heat-inactivated nor extracted viral glycoproteins could prime for HTL-P detection. The relevance of these findings for the future use of subunit vaccines against HSV is briefly discussed.
Prominence of IgG4 in the IgG antibody response to human filariasis.
Authors: Ottesen E A , Skvaril F , Tripathy S P , Poindexter R W , Hussain R
Published: December 2022

The four subclasses of IgG are distinct in structure, function, and degree of participation in the response to complex antigens. Because these differences could have important pathogenetic significance, we analyzed total and filaria antigen-specific IgG of each subclass in 31 patients with different clinical manifestations of Bancroftian filariasis. Subclass-specific, affinity-purified polyclonal antibodies were prepared from antisera raised in sheep immunized with purified myeloma IgG subclass proteins. These were radiolabeled (125I) and used to detect IgG1, IgG2, IgG3, and IgG4 in solid phase radioimmunoassays (SPRIA). The antigen-specific SPRIA was used with Brugia malayi adult antigen (BmA) bound to Sepharose 4B, whereas measurement of total IgG subclass levels in each serum was with goat anti-human IgG bound to the solid matrix. Quantification of total subclass levels was by reference to the WHO 67/97 standard, and of specific subclass antibody by development of standards from high titered sera. Although there were modest increases of total IgG1 and IgG2 in patients with filariasis compared with normals, the most striking finding was the extreme elevation of both total, and particularly, filaria antigen-specific IgG4. These elevations were seen for essentially all patients, but the relative proportion of the total IgG antibody response accounted for by IgG4 antibody was particularly marked (up to 95%) in patients with either microfilaremia or the tropical pulmonary eosinophilia syndrome. The meaning of this special prominence of the IgG4 antibody response to filarial infection is not yet clear, but the question of whether these antibodies play a role in immediate hypersensitivity reactions as either reagins or blocking antibodies is being investigated for its potential pathogenetic significance.
Monoclonal IgE-dependent eosinophil cytotoxicity to haptenated schistosomula of Schistosoma japonicum: enhancement of the cytotoxicity and expression of Fc receptors for IgE by Nippostrongylus brasiliensis infection.
Authors: Kojima S , Yamamoto N , Kanazawa T , Ovary Z
Published: December 2022

To obtain direct evidence for the involvement of IgE antibodies in eosinophil-mediated killing of schistosomula of S. japonicum, dinitrophenylated (DNP) schistosomula pretreated with mouse monoclonal IgE antibodies were co-cultured with purified rat peritoneal eosinophils. It was found that the eosinophil-mediated adherence and damage to haptenated schistosomula were dependent on a monoclonal anti-DNP IgE antibody, but not on monoclonal anti-ovalbumin IgE antibody. Moreover, eosinophils from N. brasiliensis-infected rats demonstrated an enhanced ability in the IgE-dependent damage to DNP-schistosomula as compared with the cells from normal rats. The enhancement was associated with an increase in the proportion of eosinophils expressing Fc receptors for IgE.
Cloning and complete sequence of an HLA-A2 gene: analysis of two HLA-A alleles at the nucleotide level.
Authors: Koller B H , Orr H T
Published: December 2022

The gene for the HLA-A2 antigen has been cloned from the human lymphoblastoid cell line 721. Comparison of this sequence with the published sequence for HLA-A3 permits the examination of two alleles at the extremely polymorphic HLA-A locus. A high degree of sequence conservation was seen in both coding and noncoding DNA, 97.2% and 94.5%, respectively. Interestingly, the 3' untranslated region was the most conserved, with 99.5% homology. The polymorphism of the HLA-A antigens results from a high proportion of amino acid substitutions relative to the total nucleotide changes in exons 2 and 3. Unlike the clustered differences seen in this region on comparison of two H-2K alleles of mouse, nucleotide substitutions between the HLA-A2 and A3 alleles are evenly distributed. Substitutions at silent sites and within introns were used to calculate an intra-allelic divergence time of at least 10 to 15 million years for these two HLA-A alleles.
Phorbol esters specifically inhibit induction of immunoglobulin secretion in a murine B cell leukemia.
Authors: Simpson L G , Isakson P C
Published: December 2022

We have examined the effect of tumor-promoting phorbol esters such as phorbol myristate acetate (PMA) on the murine B cell leukemia BCL-1 and its in vitro adapted derivative CW.13.20. Phorbol esters, including PMA and phorbol dibutyrate (PDBu), were potent inhibitors of BCL-1 IgM secretion induced by either LPS or lymphokines; half-maximal inhibition was obtained with 0.1 nM PMA and 0.8 nm PDBu. The inhibitory action of PDBu on BCL-1 cells was reversible for over 1 hr, but after 5 hr 70% of the inhibition was irreversible. Irreversible inhibition could be blocked by cycloheximide, suggesting a requirement for protein synthesis. The specificity of PDBu inhibition was examined by comparing the patterns of protein synthesis in PDBu-treated and control BCL-1 cells. Total incorporation of [35S]methionine into protein by BCL-1 cells cultured in the presence of PDBu was similar to that of untreated cells. Analysis of radiolabeled proteins by SDS-PAGE and autoradiography revealed no consistent changes in the pattern of protein synthesis except at those positions corresponding to the heavy and light chains of IgM. Immunoprecipitation with an affinity-purified anti-IgM indicated that PDBu inhibited the increased synthesis of heavy and light chain that follows stimulation by lymphokine but did not diminish control IgM synthesis. Induced IgM secretion from CW.13.20 cells was also inhibited by phorbol esters, indicating a direct action on B cells. Delaying the addition of phorbol ester relative to lymphokine or LPS by 24 hr significantly reduced inhibition of induced IgM secretion from both BCL-1 and CW.13.20 cells. This suggests that phorbol esters specifically interfere with the signal for induction of IgM secretion by both lymphokine and LPS.
Dimethyl sulfoxide induces expression of H-2 antigens on mouse lung carcinoma cells.
Authors: Bahler D W , Lord E M
Published: December 2022

The addition of dimethyl sulfoxide (DMSO) to cultures of line 1 carcinoma cells can increase the surface expression of H-2K and H-2D antigens at least 100-fold from barely detectable initial levels, as determined by using specific monoclonal antibodies and flow cytometry. H-2 values stabilize approximately 1 wk after exposure to maximally inducing concentrations of DMSO (3% vol) at densities found on normal spleen cells. Increased expression of H-2 antigens is not the result of cell selection, it is specific in that expression of an unrelated surface protein decreases, and it is associated with increased synthesis of these antigens as measured by incorporation of [35S]methionine. Additional DMSO-induced changes in the growth, cycling, lectin binding, and antigenic properties of line 1 cells are consistent with increased cell maturation. All changes are reversed when DMSO is removed. This system may facilitate study of products associated with differentiation that influence tumor cell malignancy.
Changes in number and density of large granular lymphocytes upon in vivo augmentation of mouse natural killer activity.
Authors: Santoni A , Piccoli M , Ortaldo J R , Mason L , Wiltrout R H , Herberman R B
Published: December 2022

NK activity of mice as well as humans and rats has been clearly associated with large granular lymphocytes (LGL). To better understand the effects of interferon (IFN) and IFN inducers on natural killer (NK) cells, we have compared the LGL in the spleens of normal and boosted mice. Cells were fractionated by centrifugation on discontinuous Percoll density gradients, and each fraction was tested for NK activity against YAC-1 targets and for the presence of LGL. In vivo treatment with C. parvum (0.7 mg/mouse, i.p., day-3), MVE-2 (25 mg/kg, i.p., day-3), poly I:C (4 mg/kg, i.p., day-3), or IFN (10(5) U/mouse, i.p., day-1) resulted in a marked augmentation and a change of distribution of cytotoxic activity. Most of the NK activity of boosted spleen cells was associated with lower density fractions 1 and 2, whereas active normal spleen cells had somewhat higher density (fractions 2 and 3). In parallel to their increased reactivity, the boosted spleens had a marked increase in the percentage of LGL, particularly in fractions 1 and 2. The augmented activity appeared to be mediated by the LGL, because treatment with anti-asialo GM1 or anti-Thy-1.2 plus complement reduced NK as well as the number of LGL. These results indicate that IFN-mediated boosting of NK activity in the spleen is due to an increase in the lower density LGL, as well as to an increase in the function of preexisting NK cells.
Immunoregulation in the rat: ontogeny of B cell responses to types 1, 2, and T-dependent antigens.
Authors: Kimura S , Eldridge J H , Michalek S M , Morisaki I , Hamada S , McGhee J R
Published: December 2022

The development of rat B cells has been examined in neonatal and adult Fischer rats through the use of type 1 (TNP-Brucella abortus), type 2 (TNP-LPS(Ph), TNP-Ficoll) and T cell-dependent (TD) (SRBC) antigens. In vivo splenic PFC responses to TNP-Brucella abortus could be induced in newborn rats and by 12 days of age had reached adult levels. In contrast, the responses to the type 2 and TD antigens were 30% and 70%, respectively, of the adult levels at 30 days of age. Adoptive transfer of the B cells from neonatal and young rats into irradiated adult hosts demonstrated that the kinetics in the development of responses to these antigens (early for type 1, intermediate for TD, and late for type 2) were not due to limiting accessory cell or T cell help in immature rats. In vitro cultures of purified B cells from neonatal and adult rats were responsive to TNP-BA and TNP-LPS(Ph) but not to TNP-Ficoll and SRBC. However, the addition of spleen cell-derived Con A supernatant to the B cell cultures resulted in responses to all four antigens, which arose as a function of B cell age, with kinetics that were identical to those observed in vivo. Fluorescent staining of B cells from rats of various ages for cell surface IgM and analysis on the fluorescence-activated cell sorter (FACS) revealed that all splenic B cells from rats 4 days of age expressed a relatively high level of sIgM, and that a subpopulation that expressed a relatively low level of sIgM increased with age until it represented approximately 50% of the adult splenic B cells. Challenging Con A supernatant-supplemented cultures of FACS-prepared low sIgM+ and high sIgM+ cells revealed that B cells responsive to TNP-Ficoll were confined to the ontogenically late-arising low sIgM+ subpopulation but that B cells responsive to TNP-BA, TNP-LPS(Ph), and SRBC were present in both subpopulations.
Ability of chicken B cells from different compartments to respond to TNP-Ficoll.
Authors: Edelman A S , Bhogal B S , Bell M K , Thorbecke G J
Published: December 2022

The responsiveness of chicken B cells from various compartments to T-independent antigens was studied by immune transfers of spleen and bursa cells into immunosuppressed recipients. Bursa cells from 8- to 10-wk-old donors failed to respond to trinitrophenylated Ficoll (TNP-F) even when thymus cells or splenic T cells were added. Spleen cells from the same donors transferred responses, as judged both by anti-TNP plaque-forming cells (PFC) per spleen and serum anti-TNP titers. In contrast, responses to TNP-Brucella abortus (TNP-BA) were transferred at least as well as by bursa as by spleen cells. Rabbit anti-chicken T cell serum plus complement treatment of the spleen cells reduced their ability to transfer responses to sheep erythrocytes, but either did not affect or enhanced serum antibody responses to TNP-BA and TNP-F. In intact animals, responsiveness to i.v. injected TNP-F was found to develop slowly after hatching in the chicken. At the age of 2 and 3 mo, PFC/spleen on day 4 after TNP-F injection were only 20% and 40%, respectively, of the adult response. Thymectomy at hatching further delayed this development, resulting in 12% and 45% of the adult control response at ages of 3 and 4 mo. It is concluded that responsiveness to the TI-2 antigen, TNP-F, develops slower than that to the TI-1 antigen, TNP-BA, and is restricted to the splenic B cell compartment. In addition, this development appears to be faster in the presence rather than in the absence of the thymus. In view of the previously shown effect of thymus on bursa development, these data suggest that the maturation of TI-1 antigen (TNP-F)-respondent chicken B cells requires residence in both the bursa and spleen before the development of responsiveness to such antigens.
Immune responses in vitro. XIII. MLR detectability of Mlsa-, Mlsb-, Mlsc-, and Mlsd-encoded products.
Authors: Click R E , Adelmann A M , Azar M M
Published: December 2022

The Mls locus was originally defined to have four alleles; all controlled products that were detectable in MLR except b, which was described as being null. More recent evidence led other investigators to postulate that the Mls locus is nonpolymorphic, being composed of only the b null allele and a singly expressed allele previously ascribed to be the a and d alleles. Our results indicate that Mlsa and Mlsd control products that are antigenically distinct and, therefore, the products cannot be controlled by the same allele. In addition, the product of Mlsb was easily detectable by Mlsa and Mlsd responding cells and cannot be considered null. Alternative explanations are considered for these conflicting results.
Human lymphocyte differentiation antigens HB-10 and HB-11. II. Differential production of B cell growth and differentiation factors by distinct helper T cell subpopulations.
Authors: Tedder T F , Cooper M D , Clement L T
Published: December 2022

Two monoclonal antibodies (HB-10 and HB-11), which react with human T, B, and NK cells, identify approximately 50% of the Leu-3+ T helper (TH) cells in adult blood. In the present studies, the functional capabilities of the HB-11+ and HB-11-TH cell subpopulations were examined after purification by fluorescence-activated cell sorting. Both subpopulations proliferated in response to PHA, Con A, PWM, and OKT-3 antibodies. The HB-11+ TH cells gave a minimal proliferative response to soluble tetanus toxoid antigen, whereas HB-11-TH cells responded well. After mitogen activation, both HB-11+ and HB-11-TH cells and to produce soluble factors which induce large B cells to proliferate. However, PWM-stimulated HB-11+TH cells were incapable of inducing B cells to differentiate into antibody-secreting plasma cells, whereas HB-11-TH cells were efficient in this regard. The results suggest that the HB-11 antigen is expressed on a subpopulation of virgin TH cells that can produce B cell growth factors but are deficient in the ability to produce B cell differentiation factors.
1,25-Dihydroxyvitamin D3 suppresses human T helper/inducer lymphocyte activity in vitro.
Authors: Lemire J M , Adams J S , Kermani-Arab V , Bakke A C , Sakai R , Jordan S C
Published: December 2022

The active form of vitamin D3, 1 alpha,25-dihydroxyvitamin D3 (1,25-(OH)2-D3), suppresses in vitro immunoglobulin (Ig) production by activated peripheral blood mononuclear cells (PBM) from normal human subjects by inhibiting T helper/inducer TH cell activity. Normal PBM were fractionated into B, TH and T suppressor/cytotoxic (Ts) cells by fluorescence-activated cell sorting techniques. The resultant subsets were activated with mitogens and were cultured in the presence or absence of a receptor-saturating concentration of 1,25-(OH)2-D3. The sterol reduced [3H]thymidine incorporation in TH cells by 56%, with no effect on Ts or B cells. When 1,25-(OH)2-D3-treated TH cells were co-cultured with untreated B cells and culture supernatants assayed for Ig production, 1,25-(OH)2-D3 abrogated the inducing effect of TH cells on Ig synthesis by B cells. There was no inhibitory effect of the sterol on Ts or B cell activity. In addition, 1,25-(OH)2-D3 produced a dramatic inhibition of interleukin 2 (IL 2) production by activated PBM, but did not inhibit IL 2 receptor generation by these cells. Other vitamin D metabolites tested did not produce this effect. These results suggest that the TH lymphocyte is the specific cellular target for the immunoinhibitory effects of 1,25-(OH)2-D3.
Subsets of human large granular lymphocytes (LGL) exhibit accessory cell functions.
Authors: Scala G , Allavena P , Ortaldo J R , Herberman R B , Oppenheim J J
Published: December 2022

The present study shows that human large granular lymphocytes (LGL) depleted of OKT3 (T lymphocytes) and Leu-M1-positive (monocytes) cells exhibit accessory cell function for the T lymphoproliferative responses to the soluble stimulants Staphylococcus protein A (SpA) or Streptolysin O (SLO), as well as to surface antigens in the autologous and allogeneic mixed leukocyte reaction (MLR). Fractionation of LGL into subsets according to their reactivity with alpha OKT11, alpha DR, and alpha OKM1 MoAb led to the identification of the subset(s) of LGL with OKT11+, DR+, OKM1+ phenotype as the antigen-presenting cell (APC), whereas the DR-, OKM1- subset(s) of LGL was completely ineffective. Furthermore, virtually all the natural killer (NK) activity of LGL was associated with OKT11+ and OKM1+, DR+ LGL that exerted the observed APC function, suggesting that NK-active cells may also act as effective APC for T lymphocyte activation. These results indicate that human LGL with NK activity may exert other noncytotoxic functions and may play a major role in immunoregulation.
Polyclonal B cell stimulation and interleukin 1 induction by the mucoid exopolysaccharide of Pseudomonas aeruginosa associated with cystic fibrosis.
Authors: Daley L , Pier G B , Liporace J D , Eardley D D
Published: December 2022

Mucoid exopolysaccharide isolated from Pseudomonas aeruginosa obtained from colonized cystic fibrosis patients was found to be a potent mitogen for mouse lymphocytes. The responding lymphocyte was a B cell, and we found no evidence that T cell could proliferate or synergize with B cells in response to the mucoid exopolysaccharide. Proliferation was not inhibitable by polymyxin B, which blocks lipopolysaccharide (LPS)-induced proliferation, indicating that a minor LPS contaminant in the purified exopolysaccharide was not the mitogenic component. Mucoid exopolysaccharide induced secretion of IgG, suggesting that it is polyclonal mitogen. It also induced splenic adherent cells (macrophages) to produce interleukin 1. We propose that mucoid exopolysaccharide produced by P. aeruginosa present in the lungs of cystic fibrosis patients may have potent in vivo consequences resulting in aberrant immunoregulation and inhibition of effective immune elimination of P. aeruginosa.
A monoclonal anti-idiotypic antibody against a human monoclonal IgM with specificity for myelin-associated glycoprotein.
Authors: Page N , Murray N , Perruisseau G , Steck A J
Published: December 2022

A human monoclonal IgM lambda antibody, directed against MAG, obtained from a patient with polyneuropathy associated with a gammopathy, was used as an immunogen to generate mouse monoclonal anti-idiotype antibodies. One hybridoma antibody, designated A8F2, reacts uniquely with the M-IgM of the patient, shows high affinity binding to the patient's M-IgM, and dose-dependently inhibits binding of the patient's M-IgM to its specific antigen MAG. Thus, A8F2 is a monoclonal anti-idiotype antibody that recognizes a region of the MAG binding site of the patient's IgM. Use of this anti-idiotype antibody in a competition RIA revealed the presence of naturally occurring anti-idiotype in the patient's serum. Because anti-idiotype antibodies may be part of a mechanism for down-regulation of antibody production, the use of A8F2 to induce a specific immunosuppression should be considered.
The idiotypic characterization of the immune response to a defined epitope of a protein antigen and the specific in vivo suppression of the immune response to this epitope by anti-idiotypic antibodies.
Authors: Norton F L , Morrow P R , Leung C Y , Benjamini E
Published: December 2022

C10, a monoclonal antibody of C3H.SW (CSW) origin, binds a decapeptide epitope of the tobacco mosaic virus protein (TMVP) representing residues 103-112 of the protein. In vivo administration of syngeneic anti-idiotypic antibodies to C10 (anti-C10) prior to immunization with TMVP suppressed the expression of antibodies to this decapeptide determinant in CSW mice without a significant reduction of the total anti-TMVP titer. The suppression could not be overcome with repeated challenges by antigen even 6 months after administration of anti-C10. Analysis of anti-C10 showed that it contains antibodies to at least two idiotopes found on C10. One of these idiotopes, C10-Idm, is found on a very small fraction of CSW anti-TMVP antibodies capable of binding the decapeptide epitope. The other idiotope, C10-IdX, is found on most of the anti-TMVP antibodies which bind the decapeptide determinant. With synthetic analogues of the decapeptide determinant, a correlation was established between the presence of the C10-IdX and the fine specificity of the decapeptide-binding antibodies. The studies reported herein demonstrate that anti-idiotypic antibodies are potent modulators of the immune response and that the C10-IdX is important in the determination of the fine specificity of antibodies to this decapeptide epitope of TMVP.
Xenopus MHC class II molecules. I. Identification and structural characterization.
Authors: Kaufman J F , Flajnik M F , Du Pasquier L , Riegert P
Published: December 2022

Class II antigens from the Xenopus laevis MHC (f haplotype) were identified by using a rabbit antihuman class II beta-chain serum (anti-p29boost). This xenoantiserum inhibits bidirectional Xenopus MLR (but not PHA-stimulation), recognizes the same molecules as certain MHC-linked Xenopus alloantisera, and immunoprecipitates class II molecules from Xenopus cells consistent with the tissue distribution of mammalian class II molecules. The Xenopus class II molecules are composed of two different chains, both of which are 30 to 35kD transmembrane glycoproteins. The alpha-chains have some N-terminal sequence homology with mammalian class II alpha-chains (both I-E/DR and I-A/DC); the beta-chains are directly recognized by anti-p29boost and have a markedly increased SDS gel mobility under nonreducing conditions. During biosynthesis, they are noncovalently associated with a number of other chains, including ones at 25kD, 33kD, and 40 to 45kD. The alpha-chains bear three N-linked glycans (two Endo H insensitive in mature material) and the beta-chains bear two (one Endo H insensitive). Unlike most mammalian class II molecules, the deglycosylated beta-chains are significantly larger and more acidic than the alpha-chains.
Xenopus MHC class II molecules. II. Polymorphism as determined by two-dimensional gel electrophoresis.
Authors: Kaufman J F , Flajnik M F , Du Pasquier L
Published: December 2022

The class II antigens from four inbred strains of Xenopus laevis (r, f, g, and j haplotypes) and six gynogenetic LG clones (two Xenopus laevis, two Xenopus gilli haplotypes) with functionally well-defined MHC types have been immunoprecipitated with the rabbit anti-human class II beta-chain serum anti-p29boost and analyzed by two-dimensional gel electrophoresis. The glycosylated material from 15-hr biosynthetically labeled cells runs as a broad fuzzy band around 33kD that, upon removal of N-linked glycans by Endo F, resolves into upper beta-chain bands and lower alpha-chain bands. Both the glycosylated and deglycosylated class II antigens give rise to multiple IEF spots in evenly spaced arrays (alpha-chain: two to eight spots in one to three arrays, beta-chain: two to 12 spots in one to five arrays). Both chains are polymorphic and both map to the functionally defined MHC. The large number of spots argues for multiple class II antigens; by radioactive N-terminal sequencing, two homologous alpha-chains and five beta-chains are present in the f haplotype. By comparison with MHC-linked alloantisera, anti-p29boost recognizes all major polymorphic class II molecules in Xenopus laevis. A selection of outbred animals were typed by using an IEF procedure requiring only a million PHA-stimulated blood cells.
Characterization of functional properties of C4-binding protein by monoclonal antibodies.
Authors: Fujita T , Kamato T , Tamura N
Published: December 2022

We prepared mouse monoclonal antibodies to human C4-binding protein (C4-bp) by fusing spleen cells from mice immunized with purified C4-bp to the mouse myeloma line P3U1. Of four monoclonal antibodies that reacted with intact C4-bp, two were specific for a 48K fragment, one of the chymotryptic cleavage products of C4-bp, and one was specific for another fragment (160K). The fourth monoclonal antibody did not react with either fragment. One of the monoclonals that reacted with the 48K fragment blocked the binding of C4-bp to cell-bound C4b. This monoclonal antibody (TK3) also inhibited two other functions of C4-bp, serving as an essential cofactor for C3b/C4b inactivator (I) in the cleavage of fluid-phase C4b and accelerating the decay of C2a from the C4b,2a complex. The other monoclonals had little or no effect on these activities of C4-bp. In addition, we found that the 48K fragment lost the binding affinity for C4b. However, it can function as a cofactor for I and as a decay-accelerator, although its activities were about 200 times weaker than intact C4-bp on a molar basis. The monoclonal antibody TK3 completely inhibited these activities of the 48K fragment. On the basis of these findings, we conclude that the functionally active site of C4-bp is located on the 48K fragment. Probably, the cofactor and decay-accelerating activities of C4-bp result from the binding of C4-bp to C4b.
Recognition of a Mr 56K glycoprotein on the surface of Plasmodium falciparum merozoites by mouse monoclonal antibodies.
Authors: Stanley H A , Howard R F , Reese R T
Published: December 2022

Hybridomas were prepared from mice repeatedly injected with disrupted Plasmodium falciparum (FVO isolate) schizonts and merozoites. Antibodies secreted by two of these hybridomas were shown by immunoelectron microscopy to bind to the surface of merozoites from the FVO isolate. These monoclonal antibodies (McAb) reacted with the FVO and Geneva isolates by an indirect fluorescence antibody test (IFAT) and immunoprecipitated a protein of relative molecular weight (Mr) 56K from both isolates. The 56K protein could be labeled with [35S] methionine and [3H]glucosamine. Glycosidase treatment of the affinity-purified polypeptide proved that the [3H]glucosamine had been incorporated into sugar side chains and that this protein (called gp56) was glycosylated. The anti-gp56 McAb did not react by IFAT or immunoprecipitation with four isolates (Honduras I, Indochina I, Tanzania I, and Kenya) that lack gp56 but contain major glycoproteins of Mr 50K. Antibodies from an Aotus monkey immune to the FVO isolate immunoprecipitated gp56 from both the FVO and Geneva isolates, but did not immunoprecipitate the 50K glycoproteins from the other four isolates. Extraction experiments conducted with the nonionic detergent Triton X-114 indicate that some of the gp56 molecules are hydrophilic and that the others are either hydrophobic or interact with hydrophobic molecules. These results, together with the electron microscopic data, suggest that the hydrophilic gp56 is a component of the extracellular matrix and that the hydrophobic gp56 may be associated with the plasma membrane of the merozoite.
Enhanced accumulation of inflammatory neutrophils and macrophages mediated by transfer of T cells from mice immunized with Listeria monocytogenes.
Authors: Czuprynski C J , Henson P M , Campbell P A
Published: December 2022

We have previously shown that listeria-immunized mice recruit more inflammatory neutrophils and macrophages to the peritoneal cavity after i.p. injection of a sterile irritant than do nonimmune mice. Because the inflammatory phagocytes that were obtained from listeria-immune and nonimmune mice did not differ in their ability to kill Listeria monocytogenes in vitro, this suggested that the rapid recruitment of listericidal inflammatory neutrophils and macrophages may be critically important for resistance to listeriosis. In this study we demonstrate that the transfer of listeria-immune T cells, which enhances recipient resistance to listeriosis, also increases the ability of recipients to mobilize inflammatory neutrophils and macrophages to the peritoneal cavity after the i.p. injection of dead listeria. The transfer of enhanced inflammatory responsiveness was blocked by pretreatment of the transferred cells with anti-Thy-1.2 plus complement, and the magnitude of the inflammatory cell accumulation was dependent on the number of listeria-immune T cells that were injected. Inflammatory neutrophils and macrophages that were obtained from the mice after the transfer of listeria-immune or nonimmune T cells (plus dead listeria) did not differ in their ability to kill L. monocytogenes in vitro. These data suggest that the elicitation of an inflammatory response may be an important event in T cell-mediated resistance to listeriosis.
Kinetics of Ii synthesis, processing, and turnover in n-butyrate-treated Burkitt's lymphoma cell lines which express or do not express class II antigens and in hairy leukemic cells.
Authors: Spiro R C , Sairenji T , Humphreys R E
Published: December 2022

We have sought to understand the role of the electrophoretically invariant chain (Ii) in class II antigen functions, particularly in certain transformed cells in which we have previously demonstrated hyperexpression of Ii. Molecular structures and relative kinetics of Ii synthesis, processing and turnover were compared in paired, Ia+ and Ia- Burkitt's lymphoma (BL) cell lines and in hairy cell leukemia (HCL) cells. Cells were metabolically labeled with [35S] methionine for 15 min (with or without a cold methionine chase to 3 hr) or were continuously labeled for 3 hr. One- and two-dimensional gel electrophoresis resolved immunoprecipitates formed with a) a heteroantiserum to purified class II antigen (demonstrating alpha and beta chains and Ii associated with that complex), b) a heteroantiserum to hairy cell leukemia (HCL) membranes (demonstrating principally the dominant, basic form of Ii molecules, class I antigens, and some additional proteins), and c) a monoclonal antibody to human Ii. Treatment of Ia+ Jijoye and its daughter, Ia- P3HR-1, BL cells with 4 mM butyrate for 48 hr enhanced the synthesis of the dominant, basic form of Ii but did not affect apparent turnover rates of that pool of Ii chains in either cell line. In Ia+ Jijoye cells but not in Ia- P3HR-1 cells Ii was terminally processed to more acidic, sialic acid-derivatized forms. Butyrate treatment did not alter the relative turnover rate of terminally processed Ii in Jijoye cells. The level of the dominant, basic form of Ii in HCL cells equaled that in butyrate-treated Jijoye cells, and relative turnover rates of this terminally unprocessed Ii pool were similar in HCL and Jijoye cells. However, HCL Ia-associated Ii was not terminally processed, as was Ia-associated Ii in Jijoye cells. The expression of Ia auxiliary proteins, p41 and p25, was also enhanced in Jijoye cells by butyrate treatment and was prominent in HCL cells. From these experiments, we may hypothesize the following. In lymphoblastoid cells, two pathways for Ii turnover could exist. One is through association with Ia complexes and progressive terminal processing of carbohydrate side chains and a second is not associated with Ia or, apparently, with such processing. Because Ii is not found to be terminally processed in the absence of class II antigen, Ia might be considered to direct the processing of a subset of Ii towards some function (rather than vice versa).(ABSTRACT TRUNCATED AT 400 WORDS)
Thymic reticulum in mice. IV. The rosette formation between phagocytic cells of the thymic reticulum and cortical type thymocytes is mediated by complement receptor type three.
Authors: el Rouby S , Praz F , Halbwachs-Mecarelli L , Papiernik M
Published: December 2022

A phagocytic cell of the thymic reticulum (P-TR) with dendritic shape recently has been isolated and characterized. We have previously shown that P-TR have an important role to play in the constitution of the thymic microenvironment. Indeed, P-TR are able to produce interleukin 1 and prostaglandin E2, both of which regulate thymocyte activation and proliferation. They are able also to stimulate the proliferation of syngeneic thymocytes enriched in the medullary type. In the present paper, we analyze a close relationship which exists between P-TR and thymocytes of the cortical type. About 25% of P-TR are able to bind to thymocytes and to form rosettes. Rosetting thymocytes represent about 5% of the total population and are PNA+, Lyt 1+2+, H-2-, and sensitive to in vivo steroid treatment. Pretreatment of P-TR with anti-Mac-1, a monoclonal rat IgG antibody against mouse macrophages and specific for complement receptor type three (CR3), abolished rosette formation. Rosette formation also was found to be inhibited by zymosan-treated serum containing the CR3 ligand, C3bi, and by certain sugars, in particular, N-acetyl-D-galactosamine and L-xylose. Our results suggest that rosetting thymocytes bind to CR3 on the P-TR membrane and that sugar constituents of the carbohydrate moieties on the thymocyte surface may serve as a recognition site during the binding process.
Identification of early stages of T lymphocyte development in the thymus cortex and medulla.
Authors: Scollay R , Shortman K
Published: December 2022

Thymocyte subpopulations with a phenotype suggesting they are early stages of T cell development in the adult mouse thymus were characterized and isolated by using multiparameter flow cytometry and sorting, in conjunction with selective killing with antibody and complement (C). The intrathymic localization of these subpopulations was assessed by dipping the thymus in fluorescent dyes to selectively label outer-cortical cells. The main phenotypic markers used were sensitivity to C-mediated lysis by the monoclonal antibody B2A2 (which spares most prothymocytes but kills most thymocytes), the expression of the T cell lineage specific markers Ly-2 and L3T4, and the levels of the common T cell antigens Ly-1 and Thy-1. A preliminary selection for cells lacking Ly-2 and L3T4, or resistant to B2A2 and C, produced a population of large cells, only 5% of all thymocytes and distinct from the typical cortical blast cells. This population of putative early thymocytes was itself heterogeneous, consisting of eight subpopulations separable by phenotype and intrathymic localization. One group of two subpopulations (B2A2-, Ly-1++, Thy-1+ and either Ly-2+ L3T4- or Ly-2- L3T4+) appeared to be of medullary location, and their phenotype suggested they could have been early members of the medullary lineages. Another group of two subpopulations (B2A2-, Ly-1++, Thy-1-, Ly-2-, L3T4- and B2A2-, Ly-1++, Thy-1+, Ly-2- L3T4-) did not show a clear localization pattern and may have represented cells in an earlier stage of transition to medullary phenotype and location. A quite different group of three subpopulations (B2A2++, Ly-1-, Thy-1-, Ly-2- L3T4-; B2A2++, Ly-1-, Thy-1+, Ly-2-, L3T4-; and B2A2++, Ly-1+, Thy-1++, Ly-2- L3T4-) was concentrated in the outer cortex and seemed to represent a series of stages of a cortical pathway, before the typical cortical blast cells. Finally, a very minor subset (0.2% of thymocytes), lacking all these markers, was concentrated in the outer cortex; this fifth group had the phenotype expected of the earliest intrathymic precursor cells. The results suggest that the separate developmental streams of cortical and medullary thymocytes may be traced back, via these minor early blast subpopulations, to common precursor cells in the outer cortex.
Enhanced activation of a T cell line specific for acetylcholine receptor (AChR) by using anti-AChR monoclonal antibodies plus receptors.
Authors: Schalke B C , Klinkert W E , Wekerle H , Dwyer D S
Published: December 2022

Immune complex-mediated regulation of the immune response has been studied by using T cell lines and monoclonal antibodies (MAb), both specific for the acetylcholine receptor (AChR). Rat T lymphocytes bearing the W3/25 phenotype and specific for AChR from Torpedo californica have been propagated in vitro for nearly 1 yr. These T cells proliferate in response to optimal concentrations of AChR presented by irradiated syngeneic thymus cells. At suboptimal concentrations of antigen there is little activation of the T cell line. We report here that the addition of small amounts of anti-AChR MAb produces dramatic stimulation of the T cell lines at suboptimal doses of AChR. Enhanced activation depends on the isotype and not the fine specificity of the MAb that are used. The observed phenomenon is antigen specific, and in fact, the immune complexes may actually suppress the proliferative response of irrelevant T cells to some extent. The MAb plus antigen are rapidly bound to the surface of the antigen-presenting cell, which we have shown is the dendritic cell.
Hormonal modulation of responses to thymus-independent and thymus-dependent antigens in autoimmune NZB/W mice.
Authors: Brick J E , Wilson D A , Walker S E
Published: December 2022

Previous work suggested that gonadal steroids influence immunity through the thymus, but the mechanisms were unclear. To investigate the effects of these hormones on immune responses to T1 and TD antigens in autoimmune mice, we studied hybrid NZB/W mice and the nonautoimmune DBA/2 strain. Mice castrated at 14 days of age were implanted with Silastic capsules releasing, in adults, physiologic levels of E2 in males or Te in females. Sham-operated controls received empty capsules. Splenic PFC were quantified 4 to 5 days after challenge with the TI2 antigen TNP-Ficoll, the TI1 antigen TNP-LPS, or the TD antigen SRBC. Young castrated NZB/W males implanted with E2 had striking enhancement of IgM responses to TNP-Ficoll when compared to castrated Te-treated females and comparable sham-operated controls of both sexes. E2 also stimulated responses to TNP-LPS. In response to challenge with SRBC, young E2-treated NZB/W males had a consistent trend to increased IgM PFC, and the stimulatory effect of E2 on IgG plaques was variable. Physiologic doses of Te had no consistent effect on responses in young mice. In old female NZB/W mice, Te caused PFC response after immunization with TNP-Ficoll to resemble age-matched NZB/W males. As sham-operated NZB/W females grew older, PFC responses to SRBC fell. This age-related phenomenon was delayed, however, in female castrates implanted with Te. In contrast, Te clearly suppressed responses to TNP-LPS. Implantation of E2 did not alter responses to TNP-Ficoll, TNP-LPS, or SRBC in nonautoimmune DBA/2 males. This finding suggested that exogenous E2 given in physiologic doses did not influence immunologic responsiveness in a normal strain to the degree seen in hormone-sensitive NZB/W mice. It was concluded that E2 enhanced responses to a variety of exogenous antigens in autoimmune NZB/W mice. The most consistent E2-induced increase in PFC response was observed with TI antigens, suggesting that E2 exerted its effects on B cells or Ts.
Differentiation of murine B cell precursors in agar culture. II. Response of precursor-enriched populations to growth stimuli and demonstration that the clonable pre-B cell assay is limiting for the B cell precursor.
Authors: Paige C J , Skarvall H , Sauter H
Published: December 2022

We established culture conditions under which fetal liver-derived B cell progenitors divide and differentiate in semisolid agar, forming colonies containing antibody-secreting cells. An important feature of this assay system is that, under certain conditions, it is limiting for only one component. This was revealed by determining the slope of the least-squares log-log regression line generated when the initial seeding density was varied. When support for the growth of the clonable pre-B cells was provided by fetal liver-derived adherent accessory cells, the slope of the regression line was 1, consistent with the interpretation that only one component, the pre-B cell, was limiting under these conditions. This interpretation was tested in the present report by positive selection for cells expressing B220, Lyb-2, or AA4.1, surface markers known to be present on cell lines of the B lineage. In all cases, an increased incidence of clonable pre-B cells was observed. Furthermore, regression analysis of titration experiments undertaken with these enriched populations revealed that the assay was still limiting for a single component. A second set of growth conditions have been defined in which the clonable pre-B assay appears to be limiting for more than one component. These conditions are obtained when the adherent accessory cells are replaced by one of three distinct hemopoietic growth factors, including CSF-1 (macrophage growth factor), GM-CSF (neutrophil/macrophage growth factor), or Multi-HGF (multi-lineage hemopoietic growth factor, also called BPA or IL 3). The most straightforward interpretation of these data is that a second cell type, distinct from the B cell precursor and dependent on the growth factors, was limiting under these conditions. In the present report, this hypothesis was confirmed because growth factor responsiveness was completely absent in B220 and Lyb-2-enriched populations. Factor responsiveness was found in unseparated fetal liver and in AA4-enriched populations. However, the AA4-enriched populations, in contrast to the B220- or Lyb-2-enriched populations, also contained a large number of factor-responsive neutrophil/macrophage colonies, raising the possibility that the effect of factors on AA4+ clonable pre-B cells was accessory cell-mediated.
Distribution of cells bearing the Tac antigen during ontogeny of human lymphoid tissue.
Authors: Hofman F M , Modlin R L , Bhoopat L , Taylor C R
Published: December 2022

The monoclonal antibody anti-Tac, which binds to the interleukin 2 (IL 2) receptor, was used to identify this antigen in human fetal and adult lymphoid tissue. Liver, spleen, thymus, lymph node, and peripheral blood were examined for Tac-positive cells with the use of frozen sections or cytocentrifuge preparations. The results show that cells in the fetal and neonatal thymus express the Tac antigen; these cells are predominantly located in the medulla. The liver and spleen of both fetus and adult exhibit very few Tac-positive cells. Double staining demonstrates that cells bearing the Tac-antigen stain with Leu-4, an anti-T cell antibody. In adult lymph node tissue, the Tac-bearing cells are predominantly distributed in the interfollicular area, with positive cells also present in the germinal center and mantle zone. The Tac antigen is present on both T and B cells. Few Tac-positive cells are present in the circulating peripheral blood.
Analysis of triiodothyronine and thyroxine-binding autoantibodies in chickens susceptible to autoimmune thyroiditis.
Authors: Brown T R , Bagchi N , Sundick R S
Published: December 2022

This report reveals a surprisingly high incidence of thyroid hormone (T3 and T4) autoantibodies (THA) and thyroglobulin autoantibodies in a closed flock of untreated Cornell strain (CS) White Leghorn chickens. This flock is closely related to the Obese strain chicken, which develops a severe spontaneous autoimmune thyroiditis. A sensitive electrophoretic autoradiographic assay for THA was developed. This assay was applied to the study of autoantibodies to T3 and T4 in the sera of adult female CS chickens. Of 109 females, 29.4% had antibodies to T3 and 18.4% had antibodies to T4. The incidence of thyroglobulin antibodies, determined by passive hemagglutination, was 15.6%. The presence of THA affected RIA measurements because serum T3 and T4 hormone concentrations appeared elevated in those birds with moderate to high antibody levels. There was major variance in the electrophoretic heterogeneity of the THA from individual chickens; i.e., some of the sera contained antibodies to T3 or T4 that appeared to be monoclonal, whereas other sera exhibited polyclonal multi-banded patterns. To determine if antibodies reactive with T3 and T4 (which are haptens) were generated by antibody responses to the T3/T4 sites on the thyroglobulin molecule, competitive binding assays were performed to determine the relative binding affinities of the antibodies for the haptens (T3/T4) and the "hapten-conjugate" (thyroglobulin). In these assays, thyroglobulin competed with the haptens, thus supporting the above hypothesis.
Interleukin 2 (IL 2) administered in vivo: influence of IL 2 route and timing on T cell growth.
Authors: Cheever M A , Thompson J A , Kern D E , Greenberg P D
Published: December 2022

The influence of the route and the frequency of IL 2 administration on the ability of IL 2 to induce the growth of activated T cells in vivo was evaluated. Initial pharmacokinetic studies confirmed that i.v. injection of IL 2 results in a relatively high peak serum concentration, but a short serum half-life. By contrast, i.p. or subcutaneous (s.c.) injection of IL 2 results in a lower peak concentration but a prolonged serum half-life. The bioavailability of IL 2 administered by these routes was assessed by measuring the in vivo growth of adoptively transferred T cells that had been previously cultured long-term with IL 2, because the growth of such cells in vivo has been shown to be proportional to the dose of IL 2 administered. The results demonstrated that i.p., s.c., or i.v. administration of IL 2 each resulted in marked donor T cell growth in vivo. Thus, IL 2 can function in vivo at sites distant to the sites of injection. In addition, the magnitude of T cell growth in vivo varied dependent on the route of IL 2 administration and correlated with the length of time IL 2 was detectable in serum, rather than the peak level achieved (i.e., IL 2 inoculated i.v. had the highest peak concentration but was least effective). As suggested by these findings, dividing the total dose of IL 2 into frequent low-dose injections was more effective in inducing T cell growth in vivo than was dividing the total dose of IL 2 into less frequent higher-dose injections. These studies confirm the great potential for IL 2 to induce the growth of activated of T cells in vivo and demonstrate that the rate of T cell growth reflects not only the dose but also the route and timing of IL 2 administration.