bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction of protective immunity against Schistosoma mansoni by a non living vaccine. I. Partial characterization of antigens recognized by antibodies from mice immunized with soluble schistosome extracts.
Authors: James S L , Pearce E J , Sher A
Published: December 2022

A single intradermal injection of frozen and thawed schistosomula in conjunction with the bacterial adjuvant Mycobacterium bovis strain Bacille Calmette Guerin, Phipps substrain (BCG) induced significant levels of resistance to challenge Schistosoma mansoni infection in C57BL/6 mice. Immunization with the aqueous fraction remaining after 100,000 X G centrifugation of the larval lysate was also protective under these conditions, suggesting that some immunogenic determinants may not be membrane associated. Frozen-thawed cercariae and soluble components of adult worms also protected against challenge infection in these experiments. These observations indicate that soluble immunogens are present in both early and late developmental stages of the parasite, and therefore may be good candidate antigens for an immunochemically defined vaccine against schistosomiasis. Induction of humoral reactivity against soluble or membrane antigens was examined in mice protected against cercarial challenge by prior exposure to frozen-thawed larvae, soluble larval, or soluble adult antigens plus BCG. Animals that were immunized with frozen-thawed larvae produced low but significant levels of antibodies against larval surface antigens when examined by indirect immunofluorescence or by immunoprecipitation of surface-labeled schistosomula. Mice immunized with soluble antigens, however, showed negligible antibody reactivity against surface membrane antigens. Because mice immunized with soluble antigens were resistant to challenge infection, these results strongly suggest that anti-surface membrane reactivity is not required in the mechanism of protective immunity in this model. Sera from mice immunized with either total freeze-thaw larval lysate or soluble schistosome extracts all showed strong reactivity against soluble antigens, as detected by ELISA. Western blot analysis showed these antisera to react with a restricted number of high m.w. antigens that were present both in schistosomula and in adult worms. These antigens are therefore likely to play a major role in the development of resistance in this model as immunogens and/or as targets of protective immune response.
Polymorphism of kappa variable region (V kappa-1) genes in inbred mice: relationship to the Ig kappa-Ef2 serum light chain marker.
Authors: Moynet D , MacLean S J , Ng K H , Anctil D , Gibson D M
Published: December 2022

We describe here the cloning and complete sequence analysis of the rearranged kappa variable region gene from the V kappa-1A-producing myeloma (C.AL20-TEPC-105). A 5'-flanking region probe from the V kappa-1A gene has been used to study the V kappa-1 germ-line gene family in strains of mice differing at the Ig kappa-Ef2 locus. All Ef2a strains examined possess an identical pair of BamHI restriction fragments strongly hybridizing to the 5' probe. Surprisingly, only two of the six strains of mice previously designated Ef2b (NZB and C58) possessed clearly altered restriction fragment sizes for V kappa-1 genes. The remaining four Ef2b strains, namely BDP/J, CE/J, I/LnJ, and P/J, appear to carry V kappa-1 genes similar to those of Ef2a strains. It is suggested that these strains may carry a third form of the V kappa-1A gene, differing in the protein coding region but indistinguishable at the DNA level with the use of BamHI or EcoRI. Alternatively, these strains may fail to express V kappa-1A light chains due to a regulatory defect involving this subgroup of kappa genes.
Rapid killing of actinomycin D-treated tumor cells by human monocytes. II. Cytotoxicity is independent of secretion of reactive oxygen intermediates and is suppressed by protease inhibitors.
Authors: Colotta F , Bersani L , Lazzarin A , Poli G , Mantovani A
Published: December 2022

Pretreatment with Actinomycin D (ActD, 1 microgram/ml for 3 hr) rendered WEHI 164 tumor cells susceptible to killing by human monocytes in a 6-hr 51Cr release assay. The present study was designed to elucidate the role of reactive oxygen intermediates (ROI) and of proteolytic enzymes in this reactivity. ActD-treated WEHI 164 cells did not trigger any measurable release of O-2 or H2O2 from monocytes. Monocytes exposed to phorbol-12-myristate-13-acetate, which enhanced release of ROI, did not show augmented killing of ActD-treated tumor cells. Scavengers of oxygen metabolites (catalase, superoxide dismutase, gluthatione, and mannitol), which inhibited ROI-mediated PMA-induced monocyte cytotoxicity against erythrocytes, did not affect monocyte killing of ActD-treated WEHI 164 cells. Enzymatically generated ROI with xanthine/xanthine-oxidase glucose/glucose-oxidase did not show preferential killing of ActD-treated WEHI 164 cells. Two patients with chronic granulomatous disease had normal levels of monocyte cytotoxicity against ActD-treated tumor cells. To determine the possible role of proteolytic enzymes in mediating this reactivity, we studied various antiproteases. Organophosphorous agents (DFP and PMSF), chloromethyl-ketone derivatives of tosylamino acids (TLCK and TPCK), Actinomyces products (pepstatin and chymostatin), and the synthetic protease substrate TAME inhibited monocyte-mediated cytotoxicity against ActD-treated WEHI 164 cells. The macromolecular protease inhibitors alpha-1 antitrypsin, bovine pancreatic trypsin inhibitor (BPTI), soybean trypsin inhibitor, and the synthetic protease substrate ATEE had little effect on monocyte cytotoxicity. When monocytes were preincubated with drugs for 1 hr and washed, TLCK, TPCK, and PMSF inhibited cytolysis, whereas the less effective chymostatin and TAME and the inactive BPTI had no effect under these conditions. Inhibition by preincubation with TLCK, PMSF, and TPCK was completely reversed after 6 hr of culture. Supernatants of monocyte cultures had lytic activity against ActD-treated WEHI 164 but not against untreated cells. Antiproteases inhibited the lytic activity of monocyte supernatants. These results strongly suggest that ROI do not play a critical role in monocyte-mediated rapid killing of drug-treated tumor cells, and that proteolytic enzymes are involved in this reactivity.
Influence of the H-2u haplotype on immune function in F1 hybrid mice. I. Antigen presentation.
Authors: Fritz R B , Skeen M J , Ziegler H K
Published: December 2022

Previously, we reported that myelin basic protein (MBP) peptide 1-37 contains an encephalitogenic epitope for PL/J mice, and MBP peptide 89-169 is encephalitogenic for SJL/J mice. (SJPL)F1 hybrid mice do not respond to immunization with these peptides in a co-dominant manner because the encephalitogenic response to peptide 1-37 dominates. To examine this phenomenon more closely, we tested the ability of MBP-primed parental or F1 T cells to respond to MBP or MBP peptides in the context of PL, SJL, or F1 antigen-presenting cells (APC). It was found that the F1 T cells responded to either the protein or the peptides when these were presented in the context of F1 or PL APC. However, F1 T cells would not respond to MBP in the context of SJL APC, although the latter cells were functionally intact. This effect was not antigen-specific because SJL APC would not present ovalbumin or PPD to primed F1 T cells. F1 T cells from mice immune to the strongly antigenic bacterium Listeria monocytogenes responded to bacterial antigens presented by SJL APC, although at a significantly lower level compared to the results obtained when these antigens were presented by F1 or PL APC. This finding implied that unbalanced antigen presentation was a quantitative rather than a qualitative phenomenon. When F1 hybrid mice from other strain combinations were tested, a similar effect was observed whenever one of the parental strains was PL/J. This effect was mapped to the MHC in MHC-congenic B10 mice.
Studies on the induction of tolerance to alloantigens. I. The abrogation of potentials for delayed-type-hypersensitivity response to alloantigens by portal venous inoculation with allogeneic cells.
Authors: Qian J , Hashimoto T , Fujiwara H , Hamaoka T
Published: December 2022

The present study investigates the effect of portal venous (p.v.) administration of allogeneic cells on the capacity of delayed-type-hypersensitivity (DTH) reactivity to alloantigens. BALB/c mice were inoculated with C3H/He spleen cells via intravenous (i.v.) or p.v. route. Intravenous injection of C3H/He spleen cells into BALB/c mice resulted in appreciable DTH responses to C3H/He alloantigens. In contrast, p.v. inoculation of the same number of C3H/He cells not only failed to induce any significant anti-C3H/He DTH responses but also abolished the capability of the animals to develop DTH responses as induced by subcutaneous (s.c.) immunization with C3H/He spleen cells. Such suppression was alloantigen-specific, since p.v. inoculation of C3H/He spleen cells resulted in selective inhibition of anti-C3H/He DTH potential without suppressing DTH responses to C57BL/6 alloantigens. This tolerance was rapidly inducible and long-lasting. When spleen cells from tolerant mice were transferred i.v. into 600 R X-irradiated syngeneic recipient mice alone or together with normal BALB/c spleen cells, these tolerant spleen cells themselves failed to induce DTH responses but did not exhibit any suppressive effect on the generation of DTH responses induced by normal spleen cells co-transferred. These results indicate that tolerance was not necessarily associated with the induction of suppressor cell activity but rather was associated with the elimination or functional impairment of clones specific for alloantigens. The results are discussed in the context of a) the role of the liver in immune responses, b) cellular mechanisms underlying the tolerance induction, and c) potential application of this approach to the future transplantation immunology.
Functional analysis of cloned macrophage hybridomas. IV. Induction and inhibition of mixed lymphocyte responses.
Authors: Ju S T , Dorf M E
Published: December 2022

A series of macrophage (M phi) hybridomas were generated by fusion of drug-marked P388D1 (H-2d) tumor cells with CKB (H-2k) splenic adherent cells. The ability of this panel of cloned M phi hybridomas expressing various levels of surface Ia antigens to induce allogeneic mixed lymphocytes responses (MLR) was examined. All MLR stimulatory M phi hybridomas expressed surface Ia antigens. However, some Ia+ and all Ia- M phi hybridomas were unable to induce vigorous MLR responses. Furthermore, even after induction of surface Ia antigen expression with Con A supernatants (Con A Sn) or purified interferon-gamma, the nonstimulatory M phi hybridomas remained ineffective at inducing strong MLR proliferative responses. Furthermore, addition of the latter M phi hybridoma clones (both with and without Con A Sn treatment) to conventional MLR cultures resulted in inhibition of MLR responses. The series of inhibitory M phi hybridomas secreted normal levels of IL 1 upon stimulation with lipopolysaccharide. After surface Ia induction with Con A Sn, the inhibitory M phi hybridomas could stimulate secretion of IL 2 and expression of IL 2 receptors. Moreover, although they inhibited conventional MLR responses, IL 2 production and IL 2 receptor expression were not significantly inhibited. Addition of these M phi hybridomas 24 to 48 hr after initiation of MLR response also inhibited MLR proliferation. The results indicated that the group of inhibitory M phi hybridomas can inhibit MLR responses after IL 2 secretion and acquisition of IL 2 receptors. Finally, this inhibitory activity has been maintained during 1 yr of continuous in vitro culture, and the hybridomas represent a stable "homogeneous" subpopulation of inhibitory macrophages. Thus, the inhibitory phenotype appears to reflect arrest at a distinct differentiation stage.
Stimulation of genetic resistance to marrow grafts in mice by interferon-alpha/beta.
Authors: Afifi M S , Kumar V , Bennett M
Published: December 2022

Lethally irradiated mice were infused with syngeneic, H-2 allogeneic, parental strain, or H-2 heterozygous bone marrow cells. They were injected daily with rabbit anti-mouse interferons (IFN)-alpha/beta or gamma or with IFN-alpha/beta. The growth of donor-derived cells was judged 5 days later by measuring splenic incorporation of 5-iodo-2'-deoxyuridine-125I into DNA. Antibodies to IFN-alpha/beta, but not to IFN-gamma, weakened genetic (both hybrid and allogeneic) resistance to marrow cell grafts. IFN-alpha/beta stimulated hybrid and allogeneic resistance, the latter even in genetically "poor responder" mice. Mice pretreated with silica, which weakens genetic resistance, were stimulated by IFN-alpha/beta to resist incompatible marrow cell grafts; however, IFN-alpha/beta failed to reverse the effects of antiasialo GM1 serum on marrow graft rejection. IFN-alpha/beta did not inhibit the growth of syngeneic marrow cells and did not stimulate resistance to H-2 heterozygous bone marrow cells. We propose that genetic resistance occurs in two discrete steps. In the first step, hemopoietic histocompatibility (Hh) antigens are recognized by one host cell type, and this recognition leads to IFN-alpha/beta secretion by a silica-sensitive cell. In the second step, asialo GM1-positive natural killer cells stimulated by IFN-alpha/beta recognize Hh antigens on marrow stem cells and cause rejection. The defects in resistance observed in genetically poor responder mice and in mice treated with silica appear to involve the first step in recognition. The lack of rejection of H-2 heterozygous (Hh-) marrow cells by parental strain mice injected with IFN-alpha/beta indicated that specific Hh recognition is critical in the second step of genetic resistance.
The isolation and characterization of the human helper inducer T cell subset.
Authors: Morimoto C , Letvin N L , Boyd A W , Hagan M , Brown H M , Kornacki M M , Schlossman S F
Published: December 2022

Monoclonal antibody anti-4B4 was produced by fusing NS1 myeloma with spleen cells of a mouse immunized with Saguinus oedipus lymphocyte. This anti-4B4 antibody defines a 135-KD cell surface protein that is widely distributed throughout the hematopoietic system. More importantly, anti-4B4 is reactive with functionally unique human T cell subsets. Anti-4B4 antibody was reactive with approximately 41% of unfractionated T cells, 41% of T4+ inducer cells, and approximately 43% of T8+ cytotoxic/suppressor population. This antibody subdivided peripheral blood T4+ cells into two functionally distinct populations. The T4+4B4+ subset proliferates relatively poorly upon stimulation with Con A and autologous cell antigens (AMLR) but well on exposure to soluble antigens, and it provides a good helper signal for PWM-induced Ig synthesis. The T4+4B4- subset, in contrast, proliferates well to Con A stimulation and autologous cell antigen (AMLR) but relatively poorly to soluble antigen stimulation, and provides little help to B cells for PWM-induced Ig synthesis. The T4+4B4- subset is largely 2H4+ and functions as the inducer of the T8+ suppressor cells. Thus, the present results suggest that one can divide the human T4 population into two major subsets that are phenotypically and functionally distinct, the human helper inducer subset (T4+4B4+/H.I.) and its reciprocal population defined by anti-2H4, the suppressor inducer subset (T4+2H4+/S.I.).
Astrocytes as antigen-presenting cells. I. Induction of Ia antigen expression on astrocytes by T cells via immune interferon and its effect on antigen presentation.
Authors: Fierz W , Endler B , Reske K , Wekerle H , Fontana A
Published: December 2022

Ia antigens seem to control immune responses on at least two levels. First, they influence the antigen recognition repertoire of the T cells. Second, their variable expression on certain antigen-presenting cells is a powerful regulatory mechanism for the local immune reaction. This is particularly important in the central nervous system (CNS) in which no Ia antigens are normally expressed. Recent experiments in this context have shown that astrocytes are able to express Ia antigens during interaction with T cells, and that they function as antigen-presenting cells. The Ia-inducing activity is produced by activated T cells, and can be replaced by immune interferon (IFN-gamma). In this study we report on the functional and kinetic relationship between Ia antigen expression on astrocytes and the immune-specific activation of T cells by astrocytes. Normal resting astrocytes were found to be negative for Ia antigens by immunofluorescence and by biochemical criteria. Moreover, they are only able to stimulate T cells after they have been induced to express Ia antigens by a signal from the T cells, which is probably mediated by IFN-gamma. In conclusion, the immune-specific interaction between astrocytes and T lymphocytes is a sensitively controlled system that might be pivotal to the development of immune responses in the brain. Malfunction of the system could be an important factor in the pathogenesis of aberrant immune reactions in the CNS, e.g., in multiple sclerosis.
Ecto-5'-nucleotidase can provide the total purine requirements of mitogen-stimulated human T cells and rapidly dividing human B lymphoblastoid cells.
Authors: Thompson L F
Published: December 2022

The ability of mitogen-stimulated human T cells or rapidly dividing human B lymphoblastoid cells to drive their total purine requirements from inosine 5'-monophosphate, inosine, or hypoxanthine was compared. Inosine 5'-monophosphate first must be converted to inosine by the action of the enzyme ecto-5'-nucleotidase before it can be transported into the cell; inosine and hypoxanthine, however, can be transported directly. Mitogen-stimulated human peripheral blood T cells were treated with aminopterin to inhibit purine synthesis de novo and to make the cells dependent on an exogenous purine source. Thymidine was added as a source of pyrimidines. Under these conditions, 30 microM inosine 5'-monophosphate, inosine, and hypoxanthine showed comparable abilities to support [3H]thymidine incorporation into DNA or [3H]leucine incorporation into protein at rates equal to that of untreated control cultures. Similar results were found when azaserine was used to inhibit purine synthesis de novo, and thus DNA synthesis. In parallel experiments with the rapidly dividing human B lymphoblastoid cell line WI-L2, treatment with aminopterin (plus thymidine) inhibited the growth rate by greater than 95%. The normal growth rate was restored by the addition of 30 microM inosine 5'-monophosphate, inosine, or hypoxanthine to the medium. However, in similar experiments with cell line 1254, a derivative of WI-L2 which lacks detectable ecto-5'-nucleotidase activity, inosine and hypoxanthine (plus thymidine), but not inosine 5'-monophosphate (and thymidine) were able to restore the growth inhibition due to aminopterin. These results show that the catalytic activity of ecto-5'-nucleotidase is sufficient to meet the total purine requirements of mitogen-stimulated human T cells or rapidly dividing human B lymphoblastoid cells, and suggest that this enzyme may be important for purine salvage when rates of purine synthesis de novo are limited and/or an extracellular source of purine nucleotides is available.
Characterization of a human interleukin 1 inhibitor.
Authors: Liao Z , Haimovitz A , Chen Y , Chan J , Rosenstreich D L
Published: December 2022

Human urine contains a specific inhibitor of interleukin 1 (IL 1) that is found in increased amounts during fever. This inhibitor was purified by using a sequence of ammonium sulfate fractionation, DEAE cellulose ion-exchange chromatography, molecular sieve chromatography on Sephacryl S-200, affinity chromatography on concanavalin A (Con A) Sepharose, and polyacrylamide gel electrophoresis. Two peaks of IL 1 inhibitory material were eluted from the polyacrylamide gels. One peak contained three proteins of 29, 32, and 67 kd, respectively, which could be visualized by silver staining. The second peak contained only a small amount of the 67 kd protein. A partially purified inhibitor fraction was found to cross-react with antisera directed against two low m.w. urine trypsin inhibitors that are cleavage products of the serum inter-alpha-trypsin inhibitor. Although these findings suggest that the urine IL 1 inhibitor may be related to the inter-alpha-trypsin inhibitor, a more exact identification will require either a homogeneous inhibitor preparation or a monospecific antiserum.
Induction of human T lymphocyte motility by interleukin 2.
Authors: Kornfeld H , Berman J S , Beer D J , Center D M
Published: December 2022

Interleukin 2 (IL 2) is known to have multiple immunoenhancing activities that are related to its ability to promote the proliferation and the expression of effector functions of human T lymphocytes. We investigated the potential of IL 2 to induce human T lymphocyte migration. Unstimulated T cells did not respond to IL 2, but T cells exposed to dextran or phytohemagglutinin did respond to IL 2 concentrations from 0.01 to 10.0 U/ml, with significantly increased migration. This activity could be specifically blocked with anti-Tac antibody. Analysis of T lymphocyte subsets revealed that OKT4+ but not OKT8+ lymphocytes responded to IL 2 in the chemotaxis assay. Checkerboard analysis demonstrated that the IL 2-induced chemoattractant activity was predominantly chemotactic rather than chemokinetic in nature. The activity of IL 2 was compared with that of another chemoattractant lymphokine, lymphocyte chemoattractant factor, which was found to stimulate lymphocyte migration without prior exposure to mitogen, and which was not inhibited by anti-Tac. Our data suggest that the lymphocyte migratory response to IL 2 is under the control of the inducible receptor recognized by anti-Tac in a manner similar to the proliferative response to IL 2, but differs from proliferation in its OKT4+ cell specificity.
Augmentation of mouse natural killer cell activity by LS 2616, a new immunomodulator.
Authors: Kalland T , Alm G , Stålhandshe T
Published: December 2022

The quinoline-3-carboxamide LS 2616 administered to mice in drinking water increased spontaneous cytotoxicity against YAC-1 cells in a dose-dependent manner. The enhancement of spontaneous cytotoxicity was found to be mediated by NK cells, as judged by their lack of adherence to nylon wool columns, relative resistance to treatment with antibodies to Thy-1.2 and complement, and almost total abrogation after depletion of asialo-GM1+ cells. Enhancement of NK activity was evident after 2 days of treatment, was maximal after 4 days, and remained elevated during the 14-day exposure period studied. NK activity returned to control levels 4 days after cessation of treatment. NK activity was significantly increased in spleen, peripheral blood, lymph nodes, and bone marrow of LS 2616-treated mice, while activity in peritoneal exudate cells and thymus remained low. LS 2616 was able to elevate NK activity in several mouse strains studied, including mice homozygous for the beige gene. Serum interferon levels were not increased during treatment with LS 2616. Combined injection of the interferon inducer Poly I:C and LS 2616 did not increase NK activity above that of animals injected with Poly I:C alone. However, Poly I:C, in contrast to LS 2616, increased NK activity in peritoneal exudate cells. Studies at the single cell level revealed that LS 2616 increased NK activity by increasing the number of lytically active cells via recruitment of new target-binding cells and not by increasing the lytic activity of pre-existing binders.
Preparation and characterization of murine monoclonal antibodies that express both cold agglutinin and cryoglobulin activities.
Authors: Patel R D , Brown J C
Published: December 2022

To obtain murine cold agglutinin (CA) and cryoglobulin antibodies, BALB/c mice were hyperimmunized with heat-killed type XIV Streptococcus pneumoniae. The spleen cells of these mice were fused with either the P3 NS1/Ag4. 1 or P3 X63/Ag.653 cell line. Several stable hybridomas were obtained that produced monoclonal antibodies (Mab) that reacted with rabbit and human erythrocytes only at temperatures below 37 degrees C. Three of these Mab were also cryoglobulins, as evidenced by their insolubility at reduced temperature. All of the antibodies studied were IgM(k) and reacted with purified type XIV S. pneumoniae polysaccharide at room temperature. With one exception, all antibodies were specific for N-acetyl-lactosamine, the immunodominant sugar residue expressed on type XIV polysaccharide. Inhibition experiments demonstrated that both CA activity and cryoprecipitation were inhibited by the same sugar compounds in the same order of efficiency. The data presented strongly suggest these CA antibodies are cross-reactive members of a S. pneumoniae-specific population. Cryoprecipitation persisted in antibodies purified under conditions that would exclude the presence of trapped serum antigens. It is therefore proposed that the cryoprecipitation observed is a result of the interactions of the antibody combining sites with carbohydrate residues of adjacent antibody molecules.
Modulation of the biologic activities of IgE-binding factors. VII. Biochemical mechanisms by which glycosylation-enhancing factor activates phospholipase in lymphocytes.
Authors: Akasaki M , Iwata M , Ishizaka K
Published: December 2022

Cells of the T cell hybridoma 23A4 produce IgE-binding factors lacking N-linked oligosaccharides (unglycosylated form) when they are incubated with IgE alone. In the presence of glycosylation-enhancing factor (GEF) or bradykinin, however, the same cells produce IgE-binding factors with N-linked oligosaccharides (glycosylated form). Switching the cells from the formation of unglycosylated IgE-binding factors to the formation of glycosylated factors was accompanied by the release of both glycosylation-inhibiting factor (GIF) in its phosphorylated form, i.e., phosphorylated lipomodulin, and arachidonate from the cells. Analysis of the biochemical processes for the release of GIF from 23A4 cells showed that affinity-purified GEF or bradykinin induced transient phospholipid methylation and diacylglycerol (DAG) formation, and enhanced 45Ca uptake into the cells. Inhibitors of methyltransferases, i.e., 3-deaza-adenosine plus L-homocysteine thiolactone, inhibited not only phospholipid methylation but also DAG formation and GIF release. Exogenously added 1-oleoyl-2-acetyl glycerol, i.e., a DAG that is permeable to the plasma membrane, induced the release of GIF from the cells. It was also found that 12-O-tetradecanoyl-phorbol 13-acetate (TPA) switched 23A4 cells and normal lymphocytes to the selective formation of N-glycosylated IgE-binding factor, and induced the release of GIF from the cells. 32PO4-labeled lipomodulin was detected in the extract of 23A4 cells 3 to 5 min after the addition of GEF, bradykinin, or TPA. These results indicate that GEF and bradykinin induced the activation of methyltransferases and phospholipase C for the formation of DAG, which in turn activated Ca2+-activated, phospholipid-dependent protein kinase (protein kinase C) for the phosphorylation of lipomodulin. Because lipomodulin loses phospholipase inhibitory activity after phosphorylation, increased phospholipase A2 activity would be expressed by this process.
Cyclic AMP-dependent protein kinase in Molt 4b lymphoblasts: identification by photoaffinity labeling and activation in intact cells by vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI).
Authors: O'Dorisio M S , Wood C L , Wenger G D , Vassalo L M
Published: December 2022

Molt 4b lymphoblasts have previously been shown to possess a single class of pharmacologically specific, high affinity receptors for vasoactive intestinal polypeptide (VIP). This study further explores the molecular basis for modulation of human lymphocyte function by VIP. Dose-dependent stimulation of adenylate cyclase was observed in Molt lymphoblasts over the range of 0.1 nM to 1 microM VIP. VIP-mediated by guanine nucleotide. Accumulation of intracellular cAMP was observed in the presence of either VIP or the diterpene, forskolin. The effects of these two agonists were synergistic. Two neuropeptides that share sequence homology with VIP were also studied; both peptide histidine isoleucine (PHI) and human pancreatic growth hormone releasing factor (1-44 GHRF) competed for 125I-VIP binding to Molt cells. PHI stimulated intracellular cAMP accumulation and demonstrated synergism with forskolin, whereas GHRF had no effect on cAMP. Photoaffinity labeling of 100,000 X G soluble proteins with 8-N3-[32P]cAMP followed by SDS gel electrophoresis demonstrated the presence of cAMP-dependent protein kinases I and II. Cyclic AMP-dependent protein kinase II predominated in the soluble fraction and was the only isozyme observed in particulate fractions. Protein phosphorylation was studied in Molt 4b cells preincubated with [32P]PO43- followed by addition of media alone, 1 microM peptide, or 10 microM forskolin. Cells were lysed and subjected to two-dimensional electrophoresis. Increased phosphorylation of a specific 41,000 Mr protein was observed after addition of forskolin, VIP, or PHI. A much lower concentration of VIP (1 nM) also caused a significant net increase in phosphorylation, which was of a lower magnitude. In contrast, no net effect on protein phosphorylation was seen with GHRF. These data demonstrate the presence of a functional VIP receptor that is linked to the G protein-adenylate cyclase complex. The demonstration of cAMP-dependent protein kinase and of VIP- and PHI-mediated protein phosphorylation in Molt 4b lymphoblasts provides evidence on a molecular level for neuropeptide modulation of human lymphocyte function.
Specific Schistosoma mansoni rat T cell clones. I. Generation and functional analysis in vitro and in vivo.
Authors: Pestel J , Dissous C , Dessaint J P , Louis J , Engers H , Capron A
Published: December 2022

In an attempt to determine the role of schistosome-specific T cells in the immune mechanisms developed during schistosomiasis, Schistosoma mansoni-specific T cells and clones were generated in vitro and some of their functions analyzed in vitro and in vivo in the fischer rat model. The data presented here can be summarized as follows: a) Lymph node cells (LNC) from rats primed with the excretory/secretory antigens-incubation products (IPSm) of adult worms proliferate in vitro only in response to the homologous schistosome antigens and not to unrelated antigens (Ag) such as ovalbumin (OVA) or Dipetalonema viteae and Fasciola hepatica parasite extracts. b) After in vitro restimulation of the primed LNC population with IPSm in the presence of antigen-presenting cells (APC) and maintenance in IL 2-containing medium, the frequency of IPSm-specific T cells is increased and the T cells can be restimulated only in the presence of APC possessing the same major histocompatibility complex (MHC) antigens. c) Following appropriate limiting dilution assays (LDA) (1 cell/well), 10 IPSm-specific T cell clones were obtained, and two of four maintained in culture were tested for their helper activity because they expressed only the W3/13+ W3/25+ surface phenotypes. d) The two highly proliferating IPSm-specific T cell clones (G5 and E23) exhibit an IPSm-dependent helper activity, as shown by the increase in IgG production by IPSm-primed B cells. e) IPSm-T cell clone (G5) as well as IPSm-T cell lines when injected in S. mansoni-infested rats can exert an in vivo helper activity, which is characterized by an accelerated production of IgG antibodies specific for the previously identified 30 to 40 kilodaltons (kd) schistosomula surface antigens (Ag). As recent studies have demonstrated that rat monoclonal antibodies recognize some incubation products of adult S. mansoni as well as one of the 30 to 40 kd schistosomula surface antigens, and taking into account the fact that the T cell clones here studied were restimulated either with IPSm or with schistosomulum Ag, it appears that such IPSm-specific T cell clones could be involved in the concomitant immunity mechanisms.
Construction of novel class I histocompatibility antigens by interspecies exon shuffling.
Authors: Engelhard V H , Yannelli J R , Evans G A , Walk S F , Holterman M J
Published: December 2022

Human and mouse class I histocompatibility antigens share considerable structural homology at both the protein and DNA sequence level. This homology has allowed the production of hybrid class I molecules by the reciprocal exchange of DNA sequences corresponding to equivalent domains of HLA-B7 and either H-2Ld or H-2Dd. It is shown that these genes give rise to protein products that are stably expressed on the surface of murine L cells after DNA-mediated gene transfer. These proteins express only those monoclonal antibody-defined H-2 determinants that are expected based on their genetic construction. The molecules have allowed the localization of a number of polymorphic and monomorphic HLA-specific epitopes. In all but one case, expression of an epitope on a domain does not appear to be influenced by the replacement of adjacent human domains with their murine equivalents, suggesting a considerable degree of structural independence of the domains. Cells expressing the hybrid molecules have also been tested as targets for a panel of HLA-B7-specific cytotoxic T cell clones. The results show that the polymorphic determinants recognized by these clones map to the alpha 1 and alpha 2 domains of the HLA-B7 molecule. No evidence for an influence of species-related amino acid sequence differences in the third extracellular domain on T cell recognition was seen. The results are discussed in light of the proposed domain structure of the class I proteins and the potential use of such molecules for further functional studies.
Immunologic mechanisms in the pathogenesis of virus-induced leukemia. IV. Mechanism of target cell recognition by autoreactive thymocytes.
Authors: Proffitt M R , Kozak C , de la Motte C , Caulfield M J
Published: December 2022

Neonatal infection of mice with Moloney murine leukemia virus (MuLV-M) results in the establishment of a chronic virus-carrier state. Such MuLV-carrier mice exhibit several immunologic abnormalities including generalized immunosuppression and autoimmunity. Previously, we found thymocytes from MuLV-M-carrier mice to be cytotoxic for normal syngeneic and allogeneic fibroblasts but not for xenogeneic (hamster) target cells. However, when the same syngeneic or allogeneic target cells were infected with MuLV-M, they were "spared" from the autoreactivity, leading us to speculate that the MuLV receptor on the target cell membrane was involved in the autoreactivity. To address this question, we tested MuLV-carrier thymocytes for their ability to lyse hamster/mouse-hybrid target cells; some of which possessed chromosome 5 (which codes for the ecotropic MuLV receptor). Of the nine hybrid cell lines initially tested, only the five clones that carried chromosome 5 were killed by the autoreactive thymocytes. In additional experiments, we noted that the cytotoxic reaction was inhibited in the presence of a monoclonal antibody that reacts with an MuLV-M gp70 epitope. The results suggest that the autoreactive cytotoxicity is mediated, at least in part, through the formation of a "bridge" between MuLV budding from the membrane of the thymocytes and the ecotropic MuLV receptor on the target cells.
Systematic comparison of antibody-mediated mechanisms of keratinocyte lysis in vitro.
Authors: Norris D A , Ryan S B , Kissinger R M , Fritz K A , Boyce S T
Published: December 2022

We have conducted a systematic comparison of lysis of TNP-coated keratinocyte targets by TNP-specific antibody, by antibody plus complement, by antibody-dependent cellular cytotoxicity (ADCC), and by natural killing with the use of monocyte, lymphocyte, and neutrophil effectors. With chromium-release assays, human keratinocytes, HEp-2 cells (transformed human keratinocytes), PAM 212 cells (transformed mouse keratinocytes), and RSC (transformed rabbit keratinocytes) were all susceptible to monocyte- and lymphocyte-mediated ADCC (p less than 0.01 to p less than 0.02). All trypsinized keratinocyte targets were also susceptible to natural killing by monocyte or lymphocyte effectors (p = 0.05 to p less than 0.001). Antibody and antibody plus complement were poor mediators of keratinocyte lysis. If protein and complex lipid synthesis of keratinocytes were inhibited by 16-hr cycloheximide preincubation, then keratinocytes were susceptible to complement-mediated lysis, implying that the resistance of these cells to complement may be due to repair of transmembrane pores. Comparison of chromium-release assays with fluorescein diacetate dye uptake viability assays showed that human keratinocytes were still susceptible to monocyte and lymphocyte ADCC but not to antibody, antibody plus complement, or natural killing. The reproducible and uniform susceptibility of normal and transformed keratinocyte targets from three different species to monocyte and lymphocyte ADCC supports the hypothesis that this mechanism of cellular lysis may be important in antibody-associated diseases of epidermal cytotoxicity.
Alternative mechanism of protein A-immunoglobulin interaction the VH-associated reactivity of a monoclonal human IgM.
Authors: Vidal M A , Conde F P
Published: December 2022

The immunoglobulin site(s) that mediates the alternative mechanism of interaction between immunoglobulins and staphylococcal protein A (SpA) was studied by using a monoclonal human IgM. Several IgM fragments were tested for their inhibitory effect in a competitive binding assay of 125I-IgM to SpA. Only those fragments containing Fab mu pieces showed some inhibitory activity. The reactivity of the Fab mu region was retained in some of its subfragments, such as Fv or the VH domain, unlike isolated light chains or VL domains. Furthermore, antibodies specific for the VH domain completely inhibited the SpA-IgM interaction. These results indicate that the alternative SpA-binding site of IgM is located in VH regions.
T cell regulation of light chain expression: preferential enhancement of Ig kappa in a primary thymus-dependent response does not require affinity-based selection.
Authors: Burkly L C , Nikolic J , Wortis H H
Published: December 2022

Previously we reported that the proportion of Ig kappa to Ig lambda anti-DNP antibodies produced by day 5 of a primary response to thymus-dependent antigens was fivefold greater than the Ig kappa:Ig lambda ratios found in responses to thymus-independent antigens. To determine whether an affinity-based process explained the differences in kappa/lambda ratios seen, we measured the affinity of Ig kappa and Ig lambda antibody by using the binding ratio radioimmunoassay method, which measures the affinity of antibodies of particular isotypes without the need for prior purification. By the addition of a mild reduction step, the affinities of IgG and IgM antibody could be simultaneously measured. The affinity of day 5 Ig kappa anti-DNP evoked by DNP-KLH is not significantly higher than that of Ig lambda anti-DNP evoked by DNP-Ficoll, nor is it significantly different from that of Ig lambda antibody produced. As an alternative to affinity-based selection, it is suggested that T cells can preferentially augment Ig kappa responses.
T cell activation via CD2 [T, gp50] molecules: accessory cells are required to trigger T cell activation via CD2-D66 plus CD2-9.6/T11(1) epitopes.
Authors: Brottier P , Boumsell L , Gelin C , Bernard A
Published: December 2022

Binding monoclonal antibodies (MAb) both to D66 and 9.6/T11(1) epitopes on the CD2 [T,gp50]-defined molecule produces a high level of T cell mitosis. This was observed with a battery of MAb of different isotypes. In contrast, none of the anti-D66 or anti-9.6/T11(1)Ab could trigger T cell proliferation in combination with anti-T11(3). Moreover, all anti-D66-9.6/T11(1) pairs of MAb tested required monocytes to activate T cells which were recruited through their Fc receptors. Variations among normal individuals were observed in the level of response to anti-D66-9.6/T11(1) pairs of Ab, 75% of a population of French Caucasians giving a high response. The level of response of a given individual was determined by his accessory cells. However, the level of response of an individual appeared to be minimally influenced by the isotype of a peculiar anti-D66 or anti-9.6/T11(1) Ab. The addition of exogeneous IL 2 could overcome the removal of accessory cells or the modulation of CD3 molecules. In contrast, IL 2 receptor appearance was not overcome by removal of monocytes. Thus, T cell activation via CD2 seems to be produced by "touching" several definite regions of this molecule which trigger a cascade of events similar to those produced by mitogenic lectins. One can assume that the appropriate conformational changes of the CD2 molecule induced by anti-D66-9.6/T11(1) pairs of Ab are solely produced when they are presented by accessory cells. This leaves open the question of whether accessory cells would also play a more active role.
Requirements for T cell activation by OKT3 monoclonal antibody: role of modulation of T3 molecules and interleukin 1.
Authors: Schwab R , Crow M K , Russo C , Weksler M E
Published: December 2022

The requirements for activation of human peripheral blood T cells by the mitogenic monoclonal antibody OKT3 were examined. OKT3 binds to a T cell molecule, T3, associated with the T cell antigen receptor and involved in T cell activation. Activation of T cells by OKT3 requires signals provided by accessory cells and is IL 2 dependent. In the presence of accessory cells, OKT3 induces loss of T3 molecules from the cell surface, production of IL 2, expression of IL 2 receptors, and proliferation. Modulation of T3 molecules by OKT3 can be induced in the absence of accessory cells with anti-mouse IgG. These T cells, however, are not induced to express IL 2 receptors or secrete IL 2. The addition of IL 1 induces expression of IL 2 receptors, but does not induce IL 2 secretion or proliferation. Thus, peripheral blood T cells appear to have different requirements for activation compared with antigen-specific T cell clones that can be induced to produce IL 2 when stimulated with OKT3 and IL 1. Expression of IL 2 receptors does not require modulation of T3 molecules, because the binding of OKT3 to T cells in the presence of IL 1 alone is sufficient to induce IL 2 receptor expression. The results suggest that IL 2 secretion depends on cross-linking and modulation of T3 molecules, and additional, as yet undefined, accessory cell signals. The expression of IL 2 receptors and proliferation of T cells can be induced in the absence of these signals when exogenous IL 2 is provided.
Orderly expression of B cell antigens during the in vitro differentiation of nonmalignant human pre-B cells.
Authors: Hokland P , Ritz J , Schlossman S F , Nadler L M
Published: December 2022

Early human pre-B cells were isolated from fetal bone marrow and induced to differentiate in vitro under the stimulus of phorbol myristic acid or leukocyte-conditioned medium during a 48-hr culture period. Tritiated thymidine culture experiments substantiated that changes in surface marker phenotypes were not the results of outgrowth of subsets responsive to these stimuli. Interestingly, the addition of monoclonal antibodies directed against CALLA resulted in neither proliferation nor differentiation of the fetal lymphoid progenitor cells. Distinct changes in cell surface phenotypes were observed without evidence of cellular enrichment or depletion. The number of CALLA- and TdT-positive cells decreased, whereas the number of B1- and sIgM-positive cells increased. Moreover, a small number of pre-B cells could be driven to a more mature phenotype with the appearance of B2 and sIgG. In contrast, the pan-B B4 antigen did not alter significantly. These changes were even more pronounced when both induction stimuli were present. These studies, and previous studies on the subsets and differentiation of non-T cell acute lymphoblastic leukemias, suggest an orderly acquisition of B cell antigens during the stages of pre-B cell differentiation in man.
Cyclosporine-induced transplantation unresponsiveness in rat cardiac allograft recipients: in vitro determination of helper and suppressor activity.
Authors: Uhteg L C , Salomon D R , Rocher L L , Kupiec-Weglinski J W , Araujo J L , Rubin M F , Tilney N L , Carpenter C B
Published: December 2022

Lymphocytes from spleen, peripheral blood, thymus, and lymph node of naive rats, nonimmunosuppressed recipients of MHC-incompatible heart grafts, and cyclosporine-treated recipients of MHC-incompatible heart grafts were tested for their ability to augment or suppress proliferation of naive cells in an in vitro MLR co-culture assay. Rats treated with cyclosporine for only 7 days maintained their grafts indefinitely. Potent suppressor activity was found in the peripheral blood and spleen of adult naive rats. In untreated engrafted rats, increased suppressor activity was found 1 wk after transplantation and increased helper activity 2 wk after transplantation. In contrast, subnormal helper and suppressor activity was found in cyclosporine-treated rats 1 wk after transplantation. Subsequently, suppressor activity peaked at 2 to 3 wk and helper activity at 4 wk after transplantation. Beyond 5 wk, the cyclosporine-treated rat was indistinguishable from naive ungrafted rats. Two types of suppressor activity were identified that differed in buoyant density and cyclophosphamide sensitivity. Neither suppressor activity demonstrated antigen specificity. These data suggest that one role of cyclosporine in this rat model is to delay the initial helper mechanisms until generalized suppressor activity is operable. The increased antigen-nonspecific activity is only transient, presumably until the final antigen-specific mechanisms become operative.
Mechanism of accessory cell requirement in inducing IL 2 responsiveness by human T4 lymphocytes that generate colonies under PHA stimulation.
Authors: Oudrhiri N , Farcet J P , Gourdin M F , Divine M , Bouguet J , Fradelizi D , Reyes F
Published: December 2022

PHA-driven monoclonal colony formation by low concentrations of resting T4 lymphocytes in agar culture requires the presence of interleukin 2 (IL 2) and accessory cells. Using recombinant IL 2 and anti-Tac monoclonal antibody as a probe for the IL 2 receptor, we demonstrate that the requirement of accessory cells (here an irradiated B cell line) in inducing IL 2 responsiveness relies on their enhancing effect in functional IL 2 receptor expression by the T colony progenitors. Furthermore, it is shown that cell to cell interaction between accessory cells and colony progenitors results in IL 2 response, i.e., colony formation, when the IL 2 receptor density reaches a critical threshold. The asynchronism in IL 2 responsiveness expression by the T colony progenitors upon activation and the short-lived T cell-accessory cell interaction, due to accessory cell death, determine the 10% colony efficiency of the culture system. In addition, we demonstrate that the accessory function in IL 2 receptor and IL 2 responsiveness expression by the T colony progenitors can be supported by irradiated T lymphocytes as well as B cells. The absence of lineage restriction of the signal delivered by accessory cells, and the requirement of physical interaction between T colony progenitors and accessory cells, emphasize the necessity of cross-linking the activation-signal receptors in inducing IL 2 responsiveness by resting T4 cells.