bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective augmentation by recombinant interferon-gamma of the intracellular content of S-adenosylmethionine in murine macrophages.
Authors: Bonvini E , Hoffman T , Herberman R B , Varesio L
Published: December 2022

Treatment of mouse peritoneal macrophages with IFN-gamma augmented the intracellular content of S-adenosylmethionine, as measured by quantitative high-performance liquid chromatography. Accumulation of S-adenosylhomocysteine, a competitive product of S-adenosylmethionine, was not detectable, either by direct measurement of absorbance or by radioisotopic techniques in IFN-gamma-treated macrophages. However, accumulation of S-adenosylhomocysteine was observed after treatment of macrophages with known inhibitors of S-adenosylhomocysteine catabolism. No inhibition of phospholipid methylation was observed upon IFN-gamma treatment, indicating that no reduction of the S-adenosylmethionine to S-adenosylhomocysteine ratio is induced by IFN-gamma in murine macrophages. The increased content of S-adenosylmethionine was associated with the acquisition of tumoricidal activity by macrophages upon IFN-gamma treatment. LPS also augmented the cellular content of S-adenosylmethionine and activated macrophages to become cytotoxic, suggesting a common mechanism of action for IFN-gamma and LPS in macrophage activation. Treatment of macrophages with cycloleucine, an agent that induces depletion of cellular S-adenosylmethionine, made the macrophages refractory to induction of cytolytic activity by IFN-gamma, suggesting a critical role for S-adenosylmethionine in macrophage activation.
S-antigen-specific rat T cell lines recognize peptide fragments of S-antigen and mediate experimental autoimmune uveoretinitis and pinealitis.
Authors: Gregerson D S , Obritsch W F , Fling S P , Cameron J D
Published: December 2022

Two S-antigen-specific rat T cell lines expressing the T helper cell surface phenotype (W 3/25+, OX 8-) have been isolated from the spleen and lymph node cells of retinal S-antigen-immunized Lewis rats, one of which displayed neither clinical nor histopathologic signs of experimental autoimmune uveoretinitis. The other rat had recovered from severe experimental autoimmune uveoretinitis for 2 mo before isolation of the cell line. Both lines are specific for S-antigen presented by histocompatible antigen-presenting cells, and also respond in vitro to several of the peptides produced by cyanogen bromide cleavage of bovine retinal S-antigen. The lesions induced by the i.v. transfer of from 1 to 10 X 10(6) viable line cells involve the retina and pineal gland, as is found when Lewis rats are immunized with immunopathogenic doses of S-antigen. Histologic examination of the eyes and pineal glands revealed pathologic lesions typical of experimental autoimmune uveoretinitis, and consisted of marked infiltration of the retina and surrounding tissues and the pineal gland by lymphocytes and inflammatory cells. T cells capable of mediating autoimmune disease are clearly present and readily isolated from both asymptomatic and convalescent animals. No significant differences in specificity for the cyanogen bromide peptides of S-antigen or cell surface phenotype were found in the T cell lines isolated from these two rats, nor was any difference found in the specificity or titer of serum antibodies taken from the original rats for the cyanogen bromide peptides of S-antigen.
Lymphokines regulate immunoglobulin isotype expression in an antigen-specific immune response.
Authors: Tesch H , Müller W , Rajewsky K
Published: December 2022

The control of immunoglobulin class switching appears to involve T cell-derived lymphokines. Such lymphokines have been shown to affect isotype expression in polyclonally activated B cells. We show in this paper that the same lymphokines similarly control isotype expression in an antigen-specific response acting in concert with a "T cell independent" antigen. In this situation, B cell growth factor II (BCGF II) enhances the production of antigen-specific IgM antibodies, whereas the production of antigen-specific IgG1 antibodies is only observed in the presence of B cell differentiation factor gamma (BCDF gamma). These results suggest that these lymphokines (and perhaps additional ones) are involved in the control of isotype expression in antigen-specific responses.
Immunologic activity of lipopolysaccharides released from macrophages after the uptake of intact E. coli in vitro.
Authors: Duncan R L , Hoffman J , Tesh V L , Morrison D C
Published: December 2022

Lipopolysaccharides (LPS) have been isolated from culture supernatants and from cell lysates after the in vitro phagocytosis of E. coli by murine macrophages. By using E. coli radiolabeled specifically in the LPS component with [3H]galactose, our studies have shown that the macrophage-"processed" LPS is enhanced with respect to its immunostimulatory activity in comparison with control phenol-water-extracted LPS. As assessed by its ability to induce interleukin 1 production in naive macrophages or proliferation in cultures of murine splenocytes, the macrophage-processed LPS is between 10- and 100-fold greater in specific activity. Evidence is presented for both structural and chemical alterations in the LPS macromolecule.
LPS induces altered phosphate labeling of proteins in murine peritoneal macrophages.
Authors: Weiel J E , Hamilton T A , Adams D O
Published: December 2022

Covalent modification of proteins via phosphorylation is a well-documented mechanism whereby intracellular events are controlled by external stimuli. Treatment of thioglycollate-elicited, C57Bl/6 murine peritoneal macrophages with nanogram quantities of bacterial lipopolysaccharide (LPS) consistently results in altered 32Pi labeling of a specific set of proteins (e.g., proteins of 67, 37, 33, and 28 kD), as measured by autoradiography after SDS-polyacrylamide gel electrophoresis. Induction of this pattern of phosphorylation is duplicated by the lipid A moiety of LPS. The LPS-stimulated changes in phosphate labeling are both dose- and time-dependent. Of various pharmacologic agents tested, the phosphorylation pattern induced in macrophages by the tumor promoter phorbol myristic acetate shows similarity to the pattern induced by LPS. Analysis of pp 28 and pp 37 from both LPS- and PMA-treated macrophages by limited proteolysis demonstrates that these phosphoproteins are structurally related and that the sites of phosphorylation are similar for both treatment conditions. Macrophages from the genetically LPS-unresponsive C3H/HeJ strain show no alteration in their pattern of phosphorylation after treatment with LPS. Control macrophages, from C3H/HeN mice, respond to LPS in a fashion identical to that seen in C57Bl/6 macrophages. Pretreatment of macrophages with IFN-gamma potentiates the effect of LPS (i.e., yields a level of altered phosphate labeling greater than that observed with LPS or PMA alone). Together, the data indicate that LPS causes altered phosphate labeling of a defined set of proteins, and that the circumstances of this response are consistent with a possible role in coupling LPS-initiated signals to the induction of functional competence in macrophages.
In vivo effects of coronavirus-specific T cell clones: DTH inducer cells prevent a lethal infection but do not inhibit virus replication.
Authors: Stohlman S A , Matsushima G K , Casteel N , Weiner L P
Published: December 2022

A lethal infection by neurotropic JHM strain of mouse hepatitis virus was prevented by the local adoptive transfer of three virus-specific Lyt-1+2-, L3T4+ T cell clones. The transfer of Lyt-1+ T cells specific for an unrelated antigen (hen egg lysozyme) did not protect. Protection required I region compatibility between the T cells and the recipients, and was reversed either by irradiation of the cells before transfer or by pretreatment of the recipients with cyclophosphamide. Adoptive transfer prevented death due to JHM virus infection but did not result in altered antiviral immunoglobulin synthesis or the suppression of viral replication in the central nervous system (CNS). The data presented implicate a local DTH response in the protection of the host from lethal infection of the CNS by a neurotropic virus, but clearly imply that other antiviral effector mechanisms are necessary for the suppression of viral replication.
Origin and differentiation of natural killer cells. II. Functional and morphologic studies of purified NK-1.1+ cells.
Authors: Hackett J , Tutt M , Lipscomb M , Bennett M , Koo G , Kumar V
Published: December 2022

Cells bearing the NK-specific marker NK-1.1 were purified from mouse spleens by utilizing a monoclonal anti-NK-1.1 antibody and cell sorting. In normal adult mice, all of the splenic NK activity against YAC-1 cells was found in the NK-1.1+ fraction, whereas NK-1.1- cells were depleted of NK activity. The NK activity of sorted NK-1.1+ cells was enriched 15- to 30-fold over unfractionated spleen cells. Light and electron microscopic studies of purified NK-1.1+ cells showed a homogeneous population of cells, each containing one to four cytoplasmic granules. Mice whose bone marrow has been destroyed by chronic exposure to 17-beta-estradiol have very low NK activity. However, spleen cells of estradiol-treated mice contained a normal frequency of NK-1.1+ cells which bound to YAC-1 cells, but failed to lyse them even after purification and subsequent exposure to interferon-alpha/beta in vitro. It appears, therefore, that in the absence of intact bone marrow, NK-1.1+ cells may be arrested in a nonlytic and interferon-unresponsive state. Spleens of neonatal mice which have low NK activity were analyzed to ascertain whether immature NK-1.1+ cells, similar to those found in estradiol-treated mice, could be demonstrated. Spleens of 8- to 9-day-old mice also contained NK-1.1+ cells which had very low NK activity even after purification. Sorted NK-1.1+ cells were examined for cytotoxicity in mice whose NK activity was suppressed by pretreatment with Corynebacterium parvum (-15 days). In contrast to cells from estradiol-treated and neonatal mice, NK-1.1+ from mice treated with C. parvum had normal functional activity. Similarly, although NK activity of unfractionated bone marrow cells is low, sorted NK-1.1+ cells were greatly enriched for lytic activity. Thus, we conclude that cell sorting with monoclonal anti-NK-1.1 antibody provides a powerful tool for examining the mechanisms underlying various states of low NK activity, and there exist NK-1.1+, nonlytic, interferon-unresponsive cells which apparently require an intact marrow microenvironment for differentiation into mature, lytic NK cells.
Relationships between pulmonary inflammation, plasma transudation, and oxygen metabolite secretion by alveolar macrophages.
Authors: Gerberick G F , Jaffe H A , Willoughby J B , Willoughby W F
Published: December 2022

We have previously shown that alveolar macrophages from normal rabbit lungs do not synthesize reactive oxygen intermediates unless first conditioned by culture in vitro in the presence of serum for 24 to 48 hr. This conditioning process is mediated by a serum constituent that partitions on gel exclusion columns with an apparent m.w. of 30,000 to 50,000 daltons. Alveolar macrophage conditioning in vitro requires protein synthesis, is associated with the generation of membrane NADPH oxidase activity, and is reversible. We have predicted therefore that during the course of pulmonary inflammation, as observed 3 wk after i.v. injection of M. butyricum in oil, alveolar macrophages might similarly become conditioned in vivo through exposure to plasma protein transudates reaching the alveolus. In support of this hypothesis we show that after experimental production of granulomatous pulmonary inflammation in rabbits, alveolar macrophages showed an augmented capacity to secrete superoxide anion when stimulated with phorbol ester, and this enhancement increases exponentially with increased plasma transudation. This augmented enhancement was reversible, and decreased after culture in vitro in the absence of serum. Mature alveolar macrophages were responsible for this enhanced superoxide anion production rather than freshly emigrated monocytes. Moreover, superoxide anion production in this model of pulmonary inflammation appears to be an "all-or-none" phenomenon, with superoxide anion production associated with a subpopulation of optimally conditioned alveolar macrophages, whereas the remaining unconditioned alveolar macrophages produce little or none. We feel that these two classes of alveolar macrophages may be derived from inflamed and noninflamed regions of the lung, respectively, thereby reflecting the discontinuous nature of the inflammatory lesions themselves. Thus we propose that measurements of reactive oxygen intermediate production by lavaged alveolar macrophages may provide a semi-quantitative measure of chronic pulmonary inflammation.
High and low affinity receptors for interleukin 2: implications of pronase, phorbol ester, and cell membrane studies upon the basis for differential ligand affinities.
Authors: Robb R J , Rusk C M
Published: December 2022

Cellular binding sites for IL 2 exist in two forms which differ with respect to their apparent affinity for the factor. The present studies were designed to evaluate various models for the difference. Receptor-mediated internalization and covalent receptor-ligand coupling were discounted as explanations on the basis of ligand binding and elution studies on permeabilized cells and cell membranes. Phosphorylation of the receptor during activation of protein kinase C failed to modulate the ratio of high and low affinity sites, demonstrating that it also did not provide a potential mechanism. Selective destruction of low affinity receptors with pronase, on the other hand, indicated that the two forms of binding sites differed significantly in their cell surface structure. Either the two types of receptor consist of distinct molecules or the conformation of the high affinity binding sites renders them more resistant to proteolysis. Antibody inhibition studies revealed that the high affinity receptors remaining after protease treatment and their low affinity counterparts both utilized the same ligand-binding component. Thus, this result ruled out the possibility of two totally distinct receptor structures. Together, the findings support the hypothesis that other membrane components modify the conformation of the ligand-binding polypeptide to confer a high affinity protease-resistant configuration.
Detection of a regulatory idiotype on a spontaneous neonatal self-reactive hybridoma antibody.
Authors: Glotz D , Zanetti M
Published: December 2022

To investigate the physiologic relevance of an idiotype-driven regulation of the immune system, we began a search for spontaneous self-reactive hybridomas in neonatal BALB/c mice. We sought hybridoma antibodies reactive with thyroglobulin (Tg) and expressing Id62, a recurrent idiotype with regulatory properties borne on induced adult autoantibodies to Tg. We describe herein such a neonatal Tg binding/Id62-positive monoclonal antibody (mAb) B10H2, and compare it with prototype mAb 62, an adult Tg-binding/Id62-positive mAb. Both mAb react with the same Tg epitope, as demonstrated by their abilities to totally inhibit the binding of the other to Tg. Moreover, as assessed by a double-reciprocal plot of their binding to Tg, their relative affinities for Tg are comparable. Likewise, mAb B10H2 appears idiotypically similar to mAb 62 because it totally inhibits the binding of mAb 62 to homologous anti-idiotype. Finally, as previously shown for mAb 62, mAb B10H2 expresses Id62 independently on both heavy (H) and light (L) chains, as evidenced by the immunoblot binding of a specific anti-Id62 probe to separated H and L chains. By molecular genetic analysis both antibodies appear to have made use of a member of the same VH 7183 gene family. Altogether, these findings suggest that neonatal mAb B10H2 and adult mAb 62 are very similar if not identical, and regulatory idiotype Id62 may be germline encoded. Furthermore this observation supports, in general, the concept of an idiotype-driven regulation for autoimmune responses.
Intestinal mucosal mast cells from rats infected with Nippostrongylus brasiliensis contain protease-resistant chondroitin sulfate di-B proteoglycans.
Authors: Stevens R L , Lee T D , Seldin D C , Austen K F , Befus A D , Bienenstock J
Published: December 2022

Rats infected with the helminth Nippostrongylus brasiliensis were injected i.p. with 2 mCi of [35S] sulfate on days 13, 15, 17, and 19 after infection. The intestines were removed from animals on day 20 or 21 after infection, the intestinal cells were obtained by collagenase treatment and mechanical dispersion of the tissue, and the 35S-labeled mucosal mast cells (MMC) were enriched to 60 to 65% purity by Percoll centrifugation. The cell-associated 35S-labeled proteoglycans were extracted from the MMC-enriched cell preparation by the addition of detergent and 4 M guanidine HCl and were partially purified by density gradient centrifugation. The isolated proteoglycans were of approximately 150,000 m.w., were resistant to pronase degradation, and contained highly sulfated chondroitin sulfate side chains. Analysis by high-performance liquid chromatography of chondroitinase ABC-treated 35S-labeled proteoglycans from these rat MMC revealed that the chondroitin sulfate chains consisted predominantly of disaccharides with the disulfated di-B structure (IdUA-2SO4----GalNAc-4SO4) and disaccharides with the monosulfated A structure (G1cUA----GalNAc-4SO4). The ratio of disaccharides of the di-B to A structure ranged from 0.4 to 1.6 in three experiments. Small amounts of chondroitin sulfate E disaccharides (GlcUA----GalNAc-4,6-diSO4) were also detected in the chondroitinase ABC digests of the purified rat MMC proteoglycans, but no nitrous acid-susceptible heparin/heparan sulfate glycosaminoglycans were detected. The presence in normal mammalian cells of chondroitin sulfate proteoglycans that contain such a high percentage of the unusual disulfated di-B disaccharide has not been previously reported. The rat intestinal MMC proteoglycans are the first chondroitin sulfate proteoglycans that have been isolated from an enriched population of normal mast cells. They are homologous to the chondroitin sulfate-rich proteoglycans of the transformed rat basophilic leukemia-1 cell and the cultured interleukin 3-dependent mouse bone marrow-derived mast cell, in that these chondroitin sulfate proteoglycans as well as rat serosal mast cell heparin proteoglycans are all highly sulfated, protease-resistant proteoglycans.
In vitro infection of human monocytes with human T lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV).
Authors: Nicholson J K , Cross G D , Callaway C S , McDougal J S
Published: December 2022

We explored the possibility that normal human monocytes can be infected with the retrovirus human T lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV). The T4 antigen, believed to be the receptor for HTLV-III/LAV binding to CD4 cells, is found on monocytes at low levels. Anti-T4A, which recognizes an epitope on the T4 molecule, inhibits viral binding to monocytes, and virus inhibits anti-T4A binding, although inhibition in both cases is not total. Virus particles were detected in HTLV-III/LAV-pulsed monocytes by electron microscopy as early as 10 min and for up to 3 days after inoculation, although budding virus was not observed. Monocytes were exposed to virus, were washed, and were cultured. Monocyte cultures were monitored by conventional assays for virus replication: immunofluorescence detection of cytoplasmic virus, supernatant reverse transcriptase activity, and supernatant virus antigen. These assays were either negative or at the lower limits of positivity. However, the amount of infectious virus was shown to increase over time in monocyte cultures by harvesting monocytes or their culture supernatants and titrating them into assay cultures containing stimulated T cells. Virus recovery from monocytes and virus recovery from T cells differed both quantitatively and qualitatively. Recovery from T cells and T cell supernatants peaked at 3 to 6 days and declined thereafter. Recovery from monocytes and monocyte supernatants increased over time in culture and never attained the levels of T cell cultures. Taken together, these studies indicate that HTLV-III/LAV binds to monocytes via the T4 molecule and enters the cells. Infectious virus is retained and increases with time in infected monocyte cultures. Both viral binding and infection are at low levels compared with levels in T cells. Unlike the usual infection of T cells characterized by high level virus replication with cell depletion, the infection appears to be persistent in monocytes.
Analysis of a cytostatic lymphokine produced by incubation of lymphocytes with tumor cells: relationship to leukoregulin and distinction from recombinant lymphotoxin, recombinant tumor necrosis factor, and natural killer cytotoxic factor.
Authors: Sayers T J , Ransom J H , Denn A C , Herberman R B , Ortaldo J R
Published: December 2022

Supernatants from the coculture of peripheral blood lymphocytes and the NK-susceptible cell line K562 were highly growth inhibitory for a variety of tumor cell lines. No correlation was observed between the susceptibility of the target cell lines to growth inhibition and to lysis by NK cells. Rather, the spectrum of cytostatic activity and the characteristics of the soluble factor were similar to those of leukoregulin, a recently described lymphokine. The supernatants of tumor-lymphocyte cultures contained only low levels of IFN-alpha and IFN-gamma, and antibodies to interferons did not affect the observed growth inhibition. The pattern of target cell susceptibility to growth inhibition by this factor was also quite distinct from that seen with purified recombinant LT or TNF. Furthermore, monoclonal antibodies to these cytokines also had no effect on the cytostasis, arguing against a requirement for, or synergistic interaction with, low levels of these cytokines. Some of the targets susceptible to the factor were only growth inhibited but not lysed, thereby distinguishing it from NKCF. Furthermore, the cytostasis was not inhibited by mannose-6-PO4 or rabbit antibodies to granule cytolysin, both of which have been reported to block NKCF. Therefore, the results show that a cytostatic factor is released in tumor-lymphocyte incubation that is quite distinct from interferons, LT, and TNF but has characteristics that resemble those of leukoregulin.
B lymphocyte-associated antigens on terminal deoxynucleotidyl transferase-positive cells and pre-B cells in bone marrow of the rat.
Authors: Opstelten D , Deenen G J , Rozing J , Hunt S V
Published: December 2022

To investigate early stages of B lymphocytopoiesis in rat bone marrow (BM) before the expression of surface IgM (s mu), the populations of cytoplasmic mu-chain-positive (c mu+) pre-B cells and terminal deoxynucleotidyl transferase-positive (TdT+) cells were studied by double immunofluorescence microscopy. B lymphocytes that were s mu+ constituted 5%, c mu+s mu- pre-B cells 23%, and TdT+ cells 4% of nucleated cells in the BM of juvenile rats. TdT+ and pre-B cells ranged between 7 and 17 microns in diameter. TdT+ cells were slightly larger, with a modal diameter of 10.5 microns against 9 microns for pre-B cells. mu-Chains were absent from nearly all TdT+ cells. Their surface antigenic phenotype was studied by using a panel of mouse monoclonal antibodies (MAb) to rat B lymphocyte-associated antigens (Ig, Ia, and others) and T lymphocyte-associated antigens. Both pre-B cells and TdT+ lacked surface Ig and Ia but carried most of the other B lymphocyte-associated antigens analyzed. TdT+ and pre-B cells lacked those antigens found only on the T lineage. By using MAb HIS24 (detecting a non-Ig/Ia B lymphocyte-associated antigen) and fluorescence-activated cell sorting, TdT+ and pre-B cells were highly enriched. The results show that most TdT+ cells in rat BM are mu- but demonstrate strong similarity with pre-B cells in surface antigenic phenotype. Therefore, as suggested for man, a major proportion of rat BM TdT+ cells may be B lineage-cells before mu heavy chain gene expression.
Cooperativity between B lymphocyte membrane molecules: independent ligand occupancy and cross-linking of antigen receptors and Fc gamma receptors down-regulates B lymphocyte function.
Authors: Uher F , Dickler H B
Published: December 2022

IgG antibody-antigen complexes bound to B lymphocyte Fc gamma receptor (Fc gamma R) but not surface immunoglobulin inhibit the antibody-forming cell response but not proliferation of these cells in response to F(ab')2 anti-mu and lymphokines. The role of B lymphocyte antigen receptors in B lymphocyte Fc gamma R-mediated inhibition was evaluated. With the use of several different antigen receptor-dependent plaque-forming cell (PFC) responses, it was found that inhibition occurred irrespective of the type of stimulatory signal used, or whether antigen receptors were bound by antibody or occupied by nominal antigen. The degree of inhibition appeared to be directly related to the extent of antigen receptor cross-linking. Maximal inhibition only occurred if both antigen receptors and Fc gamma R were occupied by their respective ligands simultaneously during the early hours of activation. In contrast, antigen receptor-independent PFC responses to the mitogen lipopolysaccharide (LPS) were not inhibited by complexes. However, the antigen-independent TNP-specific PFC response to LPS was inhibited by the combination of IgG antibody-antigen complexes and the hapten, but by neither alone. These results suggest that a down-regulatory signal is generated by functional cooperation between Fc gamma R and antigen receptors. Generation of this inhibiting signal could be mediated by the previously described physical interaction between these two receptors, and interactions between membrane receptors may be a general mechanism utilized by lymphocytes for the integration of multiple signals.
The type-specific capsular carbohydrate of Hemophilus influenzae B is a potent mitogen for murine B lymphocytes.
Authors: Lucas A H , Asser S M
Published: December 2022

In this study we investigated the in vitro mitogenic properties of the capsular carbohydrate of Hemophilus influenzae b, polyribosylribitolphosphate (PRP). PRP was found to be a potent polyclonal activator of murine B lymphocytes. PRP induced normal B cells to undergo blastogenesis, DNA synthesis, and differentiation to IgM and IgG secretion. IgG3 accounted for the majority of the IgG. No PRP-specific antibody was detectable, indicating the polyclonal origin of the secreted immunoglobulin (Ig). T lymphocytes were neither activated by PRP nor required for B cell proliferation or Ig secretion. In addition, T cell-depleted spleen cells also depleted of accessory (A) cells by passage through Sephadex G-10 retained responsiveness to PRP. Trace lipopolysaccharide (LPS) contamination was not responsible for the mitogenic effect, as shown by the ability of C3H/HeJ spleen cells to proliferate in response to PRP and by the failure of polymyxin B to inhibit PRP-induced DNA synthesis. The B cell responses induced by PRP and LPS were similar with respect to T cell and A cell independence, to the magnitude of DNA synthesis, and to Ig secretion and the Ig isotypes expressed. These data, taken with the finding that the combination of optimal doses of PRP and LPS did not give an additive DNA synthetic response, indicate that PRP and LPS were activating similar B cell populations. However, in contrast to LPS, PRP was capable of inducing significant DNA synthesis in cultures containing as few as 1,000 B cells, suggesting that PRP-driven proliferation was less dependent on cellular interactions than the response to LPS. The differential ability of PRP and LPS to stimulate C3H/HeJ B cells and to stimulate B cell proliferation at low density indicates basic differences between these two mitogens in their mechanisms of B cell activation.
Immunologic effects of interferon-alpha in man: treatment with human recombinant interferon-alpha suppresses in vitro immunoglobulin production in patients with chronic type B hepatitis.
Authors: Peters M , Walling D M , Kelly K , Davis G L , Waggoner J G , Hoofnagle J H
Published: December 2022

The effect of human recombinant interferon-alpha on lymphocyte proliferation and differentiation was studied in 18 patients with chronic type B hepatitis who were participating in a randomized controlled trial of interferon-alpha therapy. Peripheral blood mononuclear cells (PBMC) were obtained by lymphopheresis before and during a 4 mo course of interferon. Pokeweed mitogen-induced immunoglobulin synthesis by PBMC obtained from patients before therapy was similar to that of PBMC from normal individuals. However, after 2 wk treatment with human recombinant interferon-alpha mitogen-induced immunoglobulin production was decreased by an average of 50%. Staining for cytoplasmic immunoglobulin revealed decreases that paralleled secreted immunoglobulin, indicating that interferon-alpha treatment inhibited immunoglobulin synthesis. Mixing autologous T and B cell enriched populations from before and during interferon treatment revealed that the decrease in immunoglobulin synthesis involved a defect in the B cell-enriched population. In contrast to immunoglobulin synthesis, pokeweed mitogen-induced lymphocyte proliferation was not significantly affected by in vivo administration of interferon-alpha. Thus a major effect of in vivo interferon-alpha on immunoregulation in patients with chronic type B hepatitis appears to be an inhibition of the late stages of B cell differentiation into immunoglobulin producing and secreting plasma cells.
Down-regulation of interleukin 1 (IL 1) receptor expression by IL 1 and fate of internalized 125I-labeled IL 1 beta in a human large granular lymphocyte cell line.
Authors: Matsushima K , Yodoi J , Tagaya Y , Oppenheim J J
Published: December 2022

The regulation of interleukin 1 (IL 1) receptor expression on a human large granular lymphocyte cell line, YT, and fate of internalized 125I-labeled IL 1 beta (125I-IL 1 beta) were studied. YT cells were selected for this study, because this cell line expresses a large number of specific high-affinity receptor for IL 1, responds biologically to exogenously added IL 1 by expressing high-affinity IL 2 receptors, and does not produce IL 1. YT cells constitutively express approximately 7 X 10(3) IL 1 receptors/cell with a Kd approximately 10(-10) M. Neither IL 2, phorbol myristic acid, nor lipopolysaccharide affected the total binding of 125I-IL 1 beta by YT cells. In contrast, the capacity of YT cells to bind 125I-IL 1 beta when incubated at 37 degrees C for 3 to 16 hr with a low dose of purified IL 1 beta (approximately 6 U/ml) was reduced by greater than 80%. The loss of binding capability gradually recovered by 16 hr after removal of IL 1 beta from cultured YT cells. The apparent loss of IL 1 receptor expression was accompanied by the internalization of 125I-IL 1 beta into cells. Acid treatment of YT cells to remove bound 125I-IL 1 beta at 4 degrees C showed that 50% of the 125I-IL 1 beta bound to cells could no longer be recovered after 30 min at 37 degrees C, and this increased to 80% after 3 hr at 37 degrees C. Fractionation of cell extracts on Percoll gradient additionally showed 125I-IL 1 beta to appear intracellularly after receptor binding on plasma membranes, and to be successively transferred to some membranous organelles (d approximately equal to 1.037) through an intermediate density organelle (d approximately equal to 1.050), and to finally end up in lysosomal cell fractions (d approximately equal to 1.05 to 1.08) after approximately 3 hr at 37 degrees C. Only approximately 5% of internalized 125I-IL 1 beta was released into culture media by 6 hr of incubation at 37 degrees C. However, the radioactivity in the TCA soluble fraction of the culture media increased gradually by 6 hr and a lysosomotropic enzyme, ethylamine, significantly inhibited both the transfer of internalized 125I-IL 1 beta to the lysosomal fraction and the degradation of 125I-IL 1 beta. This study represents the first evidence of autoregulation of IL 1 receptors by IL 1 and internalization of IL 1 molecules after binding to receptors.(ABSTRACT TRUNCATED AT 400 WORDS)
Recombinant IL 2 but not recombinant interferon-gamma stimulates both proliferation and IgM secretion in a Ly-1+ clone of neoplastic murine B cells (BCL1).
Authors: Brooks K H , Vitetta E S
Published: December 2022

We have used a lymphokine-responsive clone (3B3) of B leukemia cells (BCL1) to examine the effects of several recombinant and purified lymphokines. Cells from BCL1-3B3 were induced to secrete IgM in the presence of recombinant interleukin 2 (rIL 2) (10 to 50 U/ml); a concomitant increase in proliferation was observed. Recombinant interferon-gamma (rIFN-gamma) was a potent inhibitor of proliferation. In addition, rIFN-gamma did not induce an increase in IgM secretion and, when added to rIL 2-stimulated BCL1-3B3 cells, completely blocked IgM secretion at a concentration of 10 U/ml. Purified and recombinant IL 1 (rIL 1) had no significant effect on differentiation either alone or in combination with rIL 2 and/or rIFN-gamma. However, rIL 1 was able to synergize with rIL 2 in enhancing the proliferation of BCL1-3B3. The ability of cells to respond to rIL 2 was limited to the in vitro (Ly-1+) clones of BCL1 cells since the in vivo derived (Ly-1-) BCL1 cells did not differentiate in response to IL 2. Consistent with their functional response to rIL 2, cells from the in vitro clone (3B3) are IL 2-receptor-positive (IL-2R+) and the in vivo derived BCL1 cells are IL-2R-. A second set of neoplastic B cell clones derived from the AKR 225 lymphoma did not respond to rIL 2 even though they expressed receptors for IL 2 and could be induced by T cell supernatant to secrete IgM, thus indicating that expression of IL 2R is not the sole requirement for IL 2 responsiveness. The monoclonal anti-IL 2R antibody (7D4) mimicked IL 2 in its ability to stimulate differentiation of BCL1-3B3 cells. These data suggest that rIL 2 and the monoclonal anti-IL-2R antibody are capable of inducing a differentiative response in the Ly-1+ BCL1-3B3 cells that is functionally equivalent to the response evoked by the previously described lymphokine B cell differentiation factor for IgM (BCDF mu). Thus, two distinct lymphokines appear to be providing a similar signal to a clonal neoplastic B cell population. Furthermore, rIL 2 is capable of providing both a proliferative and a differentiative signal.
Induction of colony-stimulating activity (CSA) by a synthetic muramyl peptide (MDP): synergism with LPS and activity in C3H/HeJ mice and in endotoxin-tolerized mice.
Authors: Galelli A , Chedid L
Published: December 2022

Injection of MDP into mice induces a rapid elevation of monocyte-macrophage CSA in the serum. This effect can also be observed in LPS-hyporesponsive C3H/HeJ mice. MDP and LPS induce CSA synergistically in normal mice. In contrast to the tolerance that is rapidly observed after repeated administration of LPS, MDP does not lose its capacity of inducing serum CSA after repeated injections. Repeated daily injections of MDP also fail to induce tolerance to the LPS-CSA inducing effect. Furthermore, whereas mice rendered tolerant to LPS become hyporesponsive to many other bacteria or bacterial products, they remain responsive to MDP. These data showing that MDP can act synergistically with another CSA inducer, can be injected repeatedly, and can stimulate mice unresponsive to LPS suggest potentially important in vivo applications.
Characterization of an anti-peptide antibody that recognizes the murine analogue of the human T cell antigen receptor-T3 delta-chain.
Authors: Samelson L E , Weissman A M , Robey F A , Berkower I , Klausner R D
Published: December 2022

The T cell antigen receptor consists of two disulfide-linked 40,000 to 45,000 dalton glycoproteins (alpha and beta) that contain variable and constant regions analogous to those found in immunoglobulin molecules. The antigen receptor on murine T cells is noncovalently associated with four additional nonpolymorphic structures. We describe an antibody that binds one of these molecules, a 26,000 dalton glycoprotein homologous to the human T3 delta-chain. This antibody immunoprecipitates the entire antigen receptor complex from a T cell hybridoma and from normal murine thymocytes. It represents the first reagent that can immunoprecipitate the antigen receptor complex on all murine T cells.
Metabolism of 5-hydroxyicosatetraenoate by human neutrophils: production of a novel omega-oxidized derivative.
Authors: O'Flaherty J T , Wykle R L , Redman J , Samuel M , Thomas M
Published: December 2022

Human neutrophils incorporated 5-hydroxy-E,Z,Z,Z-6,8,11,14-eicosatetraenoic acid (5-HETE) into cellular triglyceride and phospholipid. They also metabolized 5-HETE into a novel, extracellularly released derivative, 5,20-dihydroxy-E,Z,Z,Z-6,8,11,14-eicosatetraenoic acid (5,20-diHETE). 5,20-diHETE formation predominated at higher substrate concentrations and longer incubation intervals. In the absence of added 5-HETE, 1 X 10(8) neutrophils stimulated with 20 microM ionophore A23187 produced up to 243 ng of 5,20-diHETE, indicating that both endogenously formed and exogenously added substrate could be oxidized at carbon 20. 5,20-diHETE was about 10- to 100-fold weaker than 5-HETE in enhancing human neutrophil degranulation responses to platelet-activating factor. omega-Oxidation appears to be a general enzymatic mechanism for inactivation of arachidonic acid metabolites.
Regulation of class II gene expression: analysis in B cell stimulatory factor 1-inducible murine pre-B cell lines.
Authors: Polla B S , Poljak A , Ohara J , Paul W E , Glimcher L H
Published: December 2022

We have analyzed the mechanism of action of BSF-1 on class II gene expression in two murine pre-B cell lines that are at different stages of differentiation. In vitro transcription assays demonstrated that BSF-1 induced rapid transcription of class II genes within 1 hr by a mechanism that was independent of protein synthesis. Although cell surface expression of class II was detectable by 2 hr after induction and persisted for up to 96 hr after removal of BSF-1, levels of class II-specific mRNA and density of cell surface class II increased to a maximum between 24 and 72 hr after induction. Furthermore, prostaglandin E2 prevented the induction of class II gene expression by BSF-1. The effects of BSF-1 are unlikely to be mediated through calcium fluxes or activation of protein kinase C, since treatment with agents such as PMA and the calcium ionophore A23187 did not result in expression of class II molecules. Other lymphokines, such as IFN-gamma, IL 1, IL 2, and IL 3, did not affect class II gene expression in these two cell lines. These data provide further insight into the mechanisms by which class II gene expression is regulated in B cells.
Potentiation of the in vitro cytotoxicity of chlorambucil by monoclonal antibodies.
Authors: Smyth M J , Pietersz G A , McKenzie I F
Published: December 2022

It had previously been shown by using polyclonal antibodies that chlorambucil (CBL) and antibody did not have to be covalently bound to selectively inhibit tumor cell growth. This paper has reexamined this phenomena by using monoclonal antibodies (MoAb) and has sought to determine how antibody may serve to focus and to increase the cytotoxic effect of non-covalently bound CBL. In vitro, it was shown that MoAb per se had no effect, the MoAb had to be reactive with and to bind to tumor target cells for CBL to have an enhanced cytotoxicity. Furthermore, not all MoAb were effective; IgM and IgG2a subclasses enhanced CBL cytotoxicity, but IgG3 did not. At the cell surface, studies clearly showed that endocytosis of CBL and MoAb did not occur, as metabolic inhibitors, and lowered temperatures, which both inhibit endocytosis, had no effect on their cytotoxicity. In addition, NH4Cl an inhibitor of lysosomal enzymes did not reduce the cytotoxicity of CBL and MoAb. Thus CBL that is non-covalently bound to MoAb enters the cell independently of the MoAb. We conclude therefore that cell-bound MoAb is able to concentrate CBL on the surface of tumor cells by an unknown mechanism thereby enabling CBL to selectively alkylate their cell membranes and subsequently inhibit additional tumor cell growth.
Analysis of deficiencies in IFN-gamma-mediated priming for tumor cytotoxicity in peritoneal macrophages from A/J mice.
Authors: Hamilton T A , Somers S D , Becton D L , Celada A , Schreiber R D , Adams D O
Published: December 2022

The functional and biochemical responses of macrophages derived from the A/J mouse strain to IFN-gamma have been studied. As compared to macrophages obtained from C57BL/6 strain mice, cells from mice of the A/J strain are deficient in their response to IFN-gamma for acquisition of tumoricidal competence. This deficiency was not due to reduced expression of surface receptors for IFN-gamma or to altered affinity of the receptor for its ligand. IFN-gamma recently has been shown to enhance the potential activity of protein kinase C (PKc) and to modulate the efflux of intracellular Ca2+ in macrophages from C57BL/6 mice. Neither of these two biochemical changes were induced in macrophages derived from A/J mice. Functional competence could, however, be pharmacologically induced in both C57BL/6- and A/J-derived macrophages by combined treatment with an ionophore plus phorbol myristic acetate, which increase intracellular Ca2+ and stimulate PKc, respectively. Although the exact nature of the deficit in A/J strain mice has not been defined, the present findings indicate that it lies between the expression of receptor and the modulation of PKc activity and Ca2+ levels. Furthermore, the data provide support for the notion that these molecular changes are important components of the stimulus-response coupling process in IFN-gamma-mediated activation of macrophages.
Correction of defective IL 3 responses of T lymphocytes from autoimmune mice.
Authors: MacNeil D , Krystal G , Fairhurst M , Waterfield J D
Published: December 2022

MRL-+ and MRL-lpr congenic mice differ by the presence and expression of the homozygous recessive lymphoproliferation (lpr) gene. One manifestation of this gene is a massive T cell proliferation that results in a generalized lymphadenopathy in older animals. Interleukin 3 (IL 3), a recently described lymphokine, has been shown to influence lymphocyte differentiation. It was possible that abberrant IL 3 production was the mechanism responsible for the lpr controlled lymphadenopathy. Consequently, in this paper we tested the MRL congenic mice for their ability to produce IL 3. We report that the T lymphocytes from MRL-+ and MRL-lpr could neither respond to pokeweed mitogen in the induction of proliferation nor produce IL 3. Moreover, IL 3 was not produced constitutively nor could be induced at any time period up to 5 days in vitro. This hyporesponsiveness was shown to be controlled at the accessory cell level. Addition of T cell-depleted peritoneal exudate cells from normal major histocompatibility complex (MHC) compatible mice was able to restore the ability to secrete IL 3 in response to pokeweed mitogen in MRL-+ and young MRL-lpr mice. The defect in the accessory cells could be overridden by two means: the incorporation of phorbol myristate acetate in the induction system and preincubation of the cells in tissue culture.
Psoriatic skin lesions contain biologically active amounts of an interleukin 1-like compound.
Authors: Camp R D , Fincham N J , Cunningham F M , Greaves M W , Morris J , Chu A
Published: December 2022

The presence of neutrophil chemoattractant material in aqueous extracts of lesional psoriatic scale has been investigated by use of an agarose microdroplet chemokinesis method in combination with ultrafiltration and high-performance liquid chromatography (HPLC). Fractions were also assayed for murine thymocyte co-stimulating activity. Aqueous extracts of psoriatic scale contained significantly greater neutrophil chemokinetic activity than extracts of scale from normal skin. Successive ultrafiltration of extracts showed that the chemokinetic material was 10 to 30 kd. Heat lability and gel filtration HPLC characteristics suggested that the major chemokinetically active material in aqueous extracts of psoriatic scale is different from C5a des arg. Reversed-phase HPLC of 0.1% trifluoroacetic acid/acetonitrile extracts of psoriatic scale revealed two clearly resolved peaks of chemokinetic activity, the major peak consistently containing thymocyte co-stimulating activity. No significant neutrophil chemokinetic activity was seen in fractions after reversed-phase HPLC of scale from normal skin. These findings suggest that a major portion of the neutrophil chemoattractant activity in aqueous extracts of psoriatic scale is due to interleukin 1-like material, which may play a role in the pathogenesis of this disease.
Compartmentalized activation of the interleukin 2 gene by lung T lymphocytes in active pulmonary sarcoidosis.
Authors: Müller-Quernheim J , Saltini C , Sondermeyer P , Crystal R G
Published: December 2022

Sarcoidosis is a systemic disorder characterized by the accumulation of large numbers of interleukin 2 (IL 2) releasing helper (Leu-3+) T cells in involved organs. To determine whether the IL 2 gene is activated in sarcoidosis T cells in a systemic manner or only at sites of disease, cells obtained by bronchoalveolar lavage of individuals with active sarcoidosis, inactive sarcoidosis, and normals were evaluated for the spontaneous presence of IL 2 transcripts by using a human IL 2 cDNA probe and Northern analysis of extracted RNA. Freshly recovered lung cells of individuals with active pulmonary sarcoidosis contained 0.85 kilobase pairs (kb) IL 2 mRNA transcripts. In contrast, no IL 2 mRNA transcripts could be detected in fresh autologous blood T cells or in purified autologous blood Leu-3+ T cells, although IL 2 mRNA transcripts were inducible in these cells by phytohemaglutinin/phorbol myristic acetate. The sarcoid lung T cells, however, did not express the IL 2 gene constitutively; when placed in culture with no stimulation and evaluated after 24 hr, they demonstrated down regulation of the amounts of IL 2 mRNA transcripts, despite the fact that they were capable of re-expressing the IL 2 gene and releasing more IL 2 in response to added activation signals. Thus the activation of the IL 2 gene in T cells in active sarcoidosis occurs at the sites of disease and is not a generalized property of T cells throughout the body, and is not sustained if the T cells are removed from the sites of disease. Although the cause of sarcoid is unknown, these observations are consistent with the concept that sarcoid is associated with local stimuli at the site of disease eliciting the Leu-3+ T cell IL 2 gene activation that plays such a critical role in the pathogenesis of this disease.