bluuebunny/crossref_metadata_2025 huggingface dataset:
Lymphocyte recruitment, regional blood flow, and vascular permeability at sites of allogeneic cellular interactions.
Authors: Hanto D W , Hopt U T , Hoffman R , Simmons R L
Published: December 2022

The mechanisms responsible for the accumulation of lymphocytes in rejecting allografts may involve lymphokine-mediated changes in blood flow and vascular permeability. Changes in lymphocyte recruitment (LR), regional blood flow (RBF), and vascular permeability (VP) were studied in paired healed subcutaneous urethane sponge grafts inoculated with specifically sensitized lymphocytes (SSL) and allogeneic target cells. Intravenous injection of Indium-111-labeled unsensitized lymphocytes (UL), rubidium-86-chloride, and Iodine-125-labeled albumin was used to assess LR, RBF, and VP, respectively. An increase in LR (p less than 0.001), RBF (p less than 0.001), and VP (p less than 0.001) could be demonstrated at the site of interaction between specifically sensitized lymphocytes and targets bearing the sensitizing alloantigen. Lymphocyte recruitment, blood flow, and vascular permeability indexes were all elevated within 4 hr after graft inoculation, peaked at 8 hr, and declined at approximately the same rate over the subsequent 24 hr. RBF returned to baseline levels by 24 hr, whereas LR and VP remained elevated. Suspension of SSL and targets in dexamethasone acetate (1 x 10(-5) M) before graft inoculation completely inhibited the early increase in RBF, but only incompletely blocked LR and VP. At 24 hr, however, VP was almost totally inhibited and LR remained elevated. These results are consistent with the idea that the interaction between SSL and specific alloantigen in vivo leads to the rapid elaboration of lymphokines, which increases RBF and VP, in addition to the accumulation of circulating unsensitized cells. These vascular effects could partly be responsible for the heterogeneity and nonspecificity of the cellular infiltrate in rejecting allografts. Specific enrichment of the graft infiltrate with sensitized cells would require that other mechanisms be operative.
Nutritional factors and autoimmunity. III. Zinc deprivation versus restricted food intake in MRL/1 mice--the distinction between interacting dietary influences.
Authors: Beach R S , Gershwin M E , Hurley L S
Published: December 2022

To investigate further the modulation of autoimmune disease by nutritional means, the influence of zinc deprivation upon the development of the immunopathology of MRL/I mice was studied. Because some effects of zinc deficiency may be due to associated inanition and consequent caloric deprivation, mice with similarly restricted food intake but adequate zinc intake were also studied. Zinc restriction was introduced at either 4 or 10 wk of age and was continued throughout the study. When zinc deficiency was introduced at 4 wk of age, a significant delay in the appearance of the physical findings of MRL/I mice, including open sores, necrotic ears, arthritis, and end-stage cachexia, was noted. In addition, zinc deficiency introduced at this age resulted in a lower incidence and titer of antibodies to dsDNA and less severe glomerulonephritis than control mice. Furthermore, the immune response of zinc-deprived MRL/I mice was better preserved than control animals, and most importantly, survival was significantly prolonged. Pair-fed controls also showed delayed progression of their disease, but animals restricted isocalorically from 4 wk of age experienced a more rapid onset of the lupus-like syndrome than did their zinc-deprived counterparts. In contrast, when zinc deprivation was introduced at 10 wk of age, it had little beneficial effect upon disease progression. Indeed, caloric restriction introduced at this age had a greater impact than did zinc deficiency. Nonetheless, despite the variable influence of zinc deprivation and pair-feeding on autoimmune disease, zinc deprivation, whether introduced at 4 or 10 wk of age, resulted in a significantly greater reduction of lymphoproliferation. Successful modulation of disease activity by nutritional changes will depend on understanding the mechanisms of these differential pathologic processes.
Functional properties of T lymphocytes and their subsets in cytomegalovirus mononucleosis.
Authors: Carney W P , Iacoviello V , Hirsch M S
Published: December 2022

Cytomegalovirus (CMV) mononucleosis is associated with diminished lymphocyte responses to mitogens and herpes virus antigens, and a reversal in the normal ratio of helper-inducer (OKT4-positive) to cytotoxic-suppressor (OKT8-positive) cells. In this report, we investigate the proliferative and cytotoxic functions of lymphocyte subpopulations from patients with CMV mononucleosis. Both mitogen responsiveness and the ability to generate cytotoxic lymphocytes against allogeneic Laz 156 cells in vitro were markedly diminished. Mononuclear cells enriched for OKT8+ lymphocytes showed little or no responsiveness to Con A; cells enriched for OKT4+ lymphocytes were considerably more responsive. During CMV mononucleosis, the predominant T cell subset is a hyporesponsive OKT8+ cell. In vitro culture of peripheral blood lymphocytes, however, resulted in a selective loss of OKT8+, OKIa+ cells, so that the remaining T cell population was composed primarily of Con A-responsive OKT4+ cells. Convalescence was associated with the return of OKT8+ responsiveness to Con A, a greater stability of OKT8+ cells during culture, and the partial recovery of ability to develop cytotoxic lymphocytes after in vitro sensitization.
In vitro immune mechanisms associated with clearance of microfilariae of Dirofilaria immitis.
Authors: El-Sadr W M , Aikawa M , Greene B M
Published: December 2022

An in vitro system has been developed to elucidate potential immune mechanisms associated with clearance of microfilariae (Mf) from the bloodstream in canine Dirofilaria immitis infection. Granulocytes as well as mononuclear cells adhere to Mf of Dirofilaria immitis in the presence of immune serum. Only granulocytes, however, were capable of killing Mf, whereas PBMC attach to but do not effectively kill Mf. In the presence of granulocytes 1% +/- 1, 10% +/- 2, and 12% +/- 3 of Mf were killed by heated normal (NDS), patent (PS), and occult serum (OS), respectively, after an 18-hr incubation. With the addition of fresh NDS there was an increase in killing to 5% +/- 1 (p less than 0.025) with heat-inactivated NDS, to 12% +/- 3 in the presence of PS and to 77% +/- 12 (p less than 0.005) in the presence of OS. On further purification of granulocyte cell populations with metrizamide gradients, neutrophils were found to be the predominant effector cells with 73% +/- 18 killing with neutrophils and 18% +/- 6 with eosinophils (p less than 0.0005). Only with neutrophils was a significant increase in killing of Mf observed when fresh NDS was added to delta OS. Fractionation of OS by gel filtration suggested that IgM was the opsonizing antibody in the occult serum. In addition, immunofluorescent studies showed only IgM bound to the surface on Mf on incubation in OS. The involvement of complement in the fresh serum enhancement of killing was supported by the finding, by immunofluorescence, of surface C3 on Mf after incubation in fresh OS.
Decrease in mitogen responsiveness of mononuclear cells from peripheral blood after epinephrine administration in humans.
Authors: Crary B , Borysenko M , Sutherland D C , Kutz I , Borysenko J Z , Benson H
Published: December 2022

A single subcutaneous injection of 0.2 mg epinephrine into healthy human subjects caused a transient lymphocytosis in peripheral blood. Mononuclear cells (MNC), isolated at various times after epinephrine administration, were cultured in the presence of mitogens. The blastogenic responses to pokeweed mitogen (PWM) and phytohemagglutinin (PHA) were significantly reduced for up to 60 min post-epinephrine (p less than 0.05); the response to concanavalin A (Con A) was reduced in the 15-min samples only. All responses returned to pre-injection levels by 120 min post-injection. Removal of adherent monocytes from MNC isolates before culture did not restore normal mitogen responsiveness. When MNC were cultured in the absence of mitogens, there was no difference in survival between pre- and post-epinephrine samples. Incubation of untreated MNC for 2 hr or 18 hr in vitro with various concentrations of epinephrine (10(-5) to 10(-1) mg/ml) had no effect upon the subsequent blastogenic response to mitogens. Other workers have reported that epinephrine administration causes alterations in the composition of the circulating lymphocyte pool. Taken together, these data suggest that the reduction in mitogen responsiveness after epinephrine is the result of changes in the distribution of lymphocyte subclasses in peripheral blood.
Characterization of helper factors distinct from interleukin 2 necessary for the generation of allospecific cytolytic T lymphocytes.
Authors: Garman R D , Fan D P
Published: December 2022

The in vitro generation of primary murine allospecific cytolytic T lymphocytes (CTL) from BALB/c (H-2d) spleen cell precursors in response to x-irradiated RDM4 (H-2k) tumor cells did not occur unless the cultures were supplemented with exogenous helper factors. Such CTL helper factors (CHF) could be provided by conditioned medium from cultures in which Sendai virus-immune BALB/c spleen cells were stimulated either with Sendai-infected cells (SC-CM) or with peptides cleaved by CNBr from intact virions (SP-CM). CHF activity stimulated by both antigens reached a maximum after day 3 of culture. In contrast, interleukin 2 (IL 2) activity peaked at day 2 and had essentially disappeared by day 4. Fractionation of day-4 SC-CM and SP-CM preparations by gel filtration revealed peaks of activity at apparent m.w. of 17,000 (CHF17) and 30,000 (CHF30). Under certain conditions, a peak of CHF activity appeared in the void volume with an apparent m.w. of 75,000 or greater. These results indicate that CHF activity is mediated by molecules distinct from IL 2.
Regulation of immune responses by I-J gene products. III. GT-specific suppressor factor is composed of separate I-J and idiotype-bearing chains.
Authors: Lei H Y , Ju S T , Dorf M E , Waltenbaugh C
Published: December 2022

Injection of poly(Glu50Tyr50)(GT) into B10.BR (H-2k) mice induces GT-specific suppressor T cells and a T cell-derived suppressor factor (TsF1), which in turn induces a second-order suppressor T cell (TS2). In the present study, we show that B10.BR GT-TSF1 is composed of separate I-Jk and idiotype-bearing chains linked by disulfide bond(s). Functional suppressive activity requires both chains to be in association. Neither chain alone can induce TS2, indicating that both chains must be seen in association and suggesting a single cellular target for the two chains. Experiments designed to interchange I-J-bearing chains of GT-TSF1 derived from different H-2 haplotypes indicate that only the homologous I-J and idiotype-bearing chains can reassociate into a suppressive moiety. These experiments may imply heterogeneity of I-J region gene products.
Endotoxin-induced T lymphocyte proliferation.
Authors: Vogel S N , Hilfiker M L , Caulfield M J
Published: December 2022

The lymphocyte response to endotoxin (LPS) has been attributed largely to the action of this agent as a polyclonal activator of B lymphocytes. In this study we found that a cloned murine interleukin 2-dependent cytotoxic T cell line, CT 6, proliferates in response to LPS, thus providing the first evidence that T cells can be stimulated directly by LPS. The response was dose and time dependent and was blocked by polymyxin B, an inhibitor of LPS-induced mitogenesis. The fact that this is a cloned T cell line, free of other potentially contaminating lymphoid cell types, precludes the possibility that this proliferation is due to contaminating B lymphocytes or is mediated by macrophage-derived products such as interleukin 1. Moreover, highly purified splenic T lymphocyte populations (purified by negative/positive selection or by a rigorous column purification procedure) contain a small subpopulation (approximately 3%) of T cells that proliferate in response to LPS. This population is missing in the endotoxin-hyporesponsive C3H/HeJ mouse. As was observed in the CT 6 line, proliferation of splenic T cells in response to LPS was inhibited by polymyxin B. Furthermore, treatment of LPS-stimulated T cells with anti-T cell antibodies plus complement blocks the uptake of 3H-thymidine by these cultures. Exogenous interleukin 1 failed to stimulate the T cell cultures comparably to LPS and therefore cannot account for the degree of stimulation observed. These findings support and extend previous findings that suggested a role for an endotoxin-sensitive T cell population in the induction of certain responses, such as LPS-induced adjuvanticity of the lymphocyte-dependent LPS induction of macrophage procoagulant activity.
Alterations in expression and glycosylation pattern of the Thy-1 glycoprotein during maturation and transformation of mouse T lymphocytes.
Authors: Carlsson S R , Stigbrand T I
Published: December 2022

The mouse Thy-1 glycoprotein of normal and transformed lymphoid cells was studied with regard to amount per cell, apparent m.w., and glycosylation characteristics. Thy-1 was measured by a solid-phase radioimmunoassay calibrated with pure mouse brain Thy-1. Thymocytes were shown to contain five times the amount of Thy-1 found in lymph node cells (1 X 10(6) vs 2 X 10(5) molecules per cell), whereas the T cell lymphomas studied (P52-127-166, RBL-5, YWA, Y191, Y274, YAC-1, RL male 1, and BW5147) varied in their Thy-1 content. The apparent m.w. of Thy-1, as determined by SDS-PAGE, was in all cases 25,000 to 30,000. However, the appearance of the Thy-1 bands revealed a size heterogeneity that was less pronounced with material from lymph node cells than from thymocytes. This band broadening seemed to be inversely correlated to the affinity for lentil lectin. Whereas half the Thy-1 molecules from thymocytes were bound to the lectin, lymph nodes Thy-1 showed 75% binding. All T lymphomas but one (BW5147) contained Thy-1 also heterogeneous in lentil lectin binding. The charge, previously shown to be dependent on the sialic acid content, was shifted to more acidic forms for lymph node Thy-1 compared to thymocytes. The T lymphomas possessed Thy-1 with charge properties similar to those of the thymocytes; the only exception was BW5147, which showed more basic forms. These results show that the expression and the glycosylation of Thy-1 is altered when thymocytes mature into immunocompetent cells and after malignant transformation of lymphocytes.
Localization of murine Igh-1a allotypic determinants by using a panel of mouse myeloma variant immunoglobulins.
Authors: Oi V T , Herzenberg L A , Birshtein B K
Published: December 2022

A number of monoclonal antibodies are available that are reactive with distinct mouse immunoglobulin allotypic determinants. By determining which ones are present on a panel of hybrid IgG2b-IgG2a immunoglobulins, we have localized some of the allotypic determinants present on the IgG2a heavy chain of the "a" allotype (Igh-1a proteins). In particular, one group of determinants--Ig(1a)9.8 (20.6B8), 17.2 (20.19.2), and 14.4 (21.74.4)--has been placed in the CH2 domain. A second group--Ig(1a)8.3 (20.8.3), 21.2 (20.11.2), and 15.3 (21.66.3)--is located in a segment spanning the C terminal 8 residues of the CH2 domain and the complete CH3 domain.
Binding of antigen-specific, H-2-restricted T cell hybridomas to antigen-pulsed adherent cell monolayers.
Authors: Marrack P , Skidmore B , Kappler J W
Published: December 2022

Two methods were investigated for studying the binding of radiolabeled hybridoma T cells to antigen (Ag) and H-2 products for which they bore receptors. In both cases hybridoma T cells were labeled with tritiated thymidine. In one method labeled cells were added to adherent splenic cells prepulsed with antigen, and the mixture was incubated overnight at 37 degrees C before nonadherent cells were gently washed away. The percent of adherent hybridoma T cells was then estimated by harvesting the adherent monolayers and measuring tritium counts bound. In a second method radiolabeled hybridoma T cells were added to adherent antigen-pulsed B cell lymphomas or hybridomas for between 15 min and 1 hr at 37 degrees C before removal of nonadherent cells and harvesting of the adherent monolayers. In both cases binding was both antigen- and I-region specific. In the second case binding was also rapid; significant binding could be measured after 15 min incubation. These techniques were used to study subclones of one of our T cell hybridomas that were thought by a functional assay (interleukin 2 release) to have lost receptors for Ag/H-2. It was found that subclones of the hybridoma that no longer secreted interleukin 2 in response to Ag/H-2, even though they continued to secrete interleukin 2 in response to concanavalin A, also no longer bound specifically to Ag-pulsed monolayers of the appropriate H-2 type. This confirmed the idea that these subclones had lost the ability to synthesize receptors for Ag/H-2. It is hoped that assays of this type will be useful in the future for the study of Ag/H-2 receptors on T cells.
The adjuvanticity of interleukin 1 in vivo.
Authors: Staruch M J , Wood D D
Published: December 2022

Interleukin 1 (IL 1) was shown to enhance in vivo secondary antibody responses of mice to a protein antigen. The activity was found to be dose and time dependent. The maximum enhancing effect was obtained with 2000 LAF units of IL 1 given 2 hr after the priming dose of antigen. The observation is consistent with the in vitro immunoenhancing activities of IL 1 and strongly suggests that this protein may be an important mediator of host defense responses, as well as of the stimulatory effects of some adjuvants.
Studies on the mechanism of natural killer cytotoxicity. II. coculture of human PBL with NK-sensitive or resistant cell lines stimulates release of natural killer cytotoxic factors (NKCF) selectively cytotoxic to NK-sensitive target cells.
Authors: Wright S C , Weitzen M L , Kahle R , Granger G A , Bonavida B
Published: December 2022

This investigation has employed the "innocent bystander" type of experimental design to determine whether soluble cytotoxic factor(s) are released during interactions between human peripheral blood lymphocytes (PBL) and NK-sensitive target cells. PBL cocultured with NK-sensitive Molt-4 or K562 target cells in the lower well of a miniaturized Marbrook culture released natural killer cytotoxic factors (NKCF), which diffused across a 0.2-mu Nucleopore membrane and lysed Molt-4 or K562 target cells cultured in the upper chamber. Coculture of PBL with the NK-resistant Raji or WI-L2 cell lines also induced release of NKCF. These factors were selectively cytotoxic to NK-sensitive targets and lysed Molt-4 and, to a lesser extent, K562 cells. However, Raji, WI-L2, and RPMI 1788 cells were all resistant to lysis. In addition, low density fractions from Percoll density gradients that were enriched for NK effector cells also released increased levels of NKCF during coculture with Molt-4 cells. Lysis of Molt-4 and K562 targets was observed after exposure to NKCF for 48 hr and 60 to 70 hr, respectively. Cellfree supernatants containing NKCF were obtained after a short time of incubation (i.e., within 5 hr of coculture of PBL with NK target cells). The factors were nondialyzable, stable at 56 degrees C for 3 hr, and showed partial loss of activity on storage at 4 degrees C or -20 degrees C for 7 days. These data suggest that NKCF may be involved in the lytic mechanism of human NK cell-mediated cytotoxicity.
Early appearance of donor-type antigen-presenting cells in the thymuses of 1200 R radiation-induced bone marrow chimeras correlates with self-recognition of donor I region gene products.
Authors: Longo D L , Davis M L
Published: December 2022

The thymus exerts a potent influence on the development of I region self-recognition and antigen recognition by T cells. The mechanism by which the thymus acts on nascent T cells is unknown. It is assumed, however, that a cell interaction between the developing T cell and an la antigen-bearing cell in the thymus is involved. There are several candidates for the critical thymic cell; thymic epithelial, nurse, and antigen-presenting cells (APC) or dendritic cells. Because thymic epithelial cells derive from the third pharyngeal pouch and thymic APC derive from bone marrow, radiation-induced bone marrow chimeras allow the artificial creation of a chimeric thymus gland in which thymic epithelial cells and APC can be genetically different. We made radiation-induced bone marrow chimeras (F1 leads to P) using supralethal radiation doses (1200 R) and found bone marrow donor- (F1) type APC in the thymuses 3 wk after radiation. When such mice fully reconstitute their immune systems, their T cells behave as donor F1 phenotype T cells. Thus, the I region self-restriction and antigen-recognition repertoire of the T cells correlates with the genotype of the bone marrow-derived thymic APC, not the thymic epithelial cell.
Complexity of the histocompatibility-3 region in the mouse.
Authors: Rammensee H G , Klein J
Published: December 2022

Congenic lines C57BL/10Sn (H-3a), B10.LP-H-3b, B10.C-H-3c, and B10.KR-H-3d were arranged into the 12 possible recipient-donor combinations and immunized. The spleen cells of each recipient were then tested for the presence of cytolytic effector T lymphocytes (CTL) specific for antigenic determinants controlled by the H-3 locus and restricted by class I H-2 loci. The strain-distribution pattern of the determinants defined by the individual CTL was determined by direct testing and by cold-target inhibition analysis. The restriction elements of the individual determinants were identified by the testing of H-2 recombinant strains and by antibody blocking. Five determinants were identified: 1 and 2, restricted by the Db molecule; 3 and 4 restricted by the Kb molecule; and 5, for which the restriction molecule could not be determined. The distribution pattern of determinants 3 and 4 correlated with the distribution of alleles at the beta 2-microglobulin locus. The data could be interpreted as arguing for the existence of three loci in the H-3 complex, with one coding for mutually antithetical determinants 1 and 2, another coding for mutually antithetical determinants 3 and 4, and still another coding for determinant 5.
Suppression of macrophage antimicrobial activity by a tumor cell product.
Authors: Szuro-Sudol A , Murray H W , Nathan C F
Published: December 2022

Medium conditioned by tumor cells (TCM) and certain nonmalignant cells contains a trypsin-sensitive factor that suppresses macrophage oxidative metabolism. Because the killing of intracellular pathogens such as Toxoplasma gondii and Leishmania donovani by macrophages is largely oxygen-dependent, we tested the effect of TCM on the antiprotozoal activity of mouse peritoneal macrophages. After 24 hr of cultivation with TCM, in vivo and in vitro activated macrophages could no longer kill toxoplasmas or inhibit their replication. In vivo administration of TCM resulted in similar impairment. The leishmanicidal activity of resident and activated macrophages, when measured 6 hr after infection, was markedly suppressed by in vitro exposure to TCM. The addition of exogenous H2O2 in the form of glucose-glucose oxidase reconstituted the capacity of TCM-exposed macrophages to kill L. donovani promastigotes as quickly as control cells. Thus, TCM appears to deactivate macrophages by the functional criteria of suppressed antitoxoplasmal and antileishmanial activity, as well as by the biochemical criterion of suppressed oxidative metabolism.
Cells in murine fetal liver and in lymphoid colonies grown from fetal liver can suppress generation of cytotoxic T lymphocytes directed against their self antigens.
Authors: Muraoka S , Miller R G
Published: December 2022

Fetal liver (FL) cells or, in much smaller numbers, cells in lymphoid colonies grown from FL of mouse strain A can suppress the development of cytotoxic activity in a B anti-A mixed lymphocyte reaction (MLR) but not a B anti-C MLR. A, B, and C represent three H-2 different mouse strains. Suppressor cells with similar properties have been described in thymus, bone marrow, lymphoid colonies grown from bone marrow, and athymic nude spleen. They have been referred to collectively as "veto cells". From the point of view of the suppressor cells, a response against self is being suppressed. The FL colony suppressor cells differ from those described in that they can sometimes also suppress an A anti-B response. The FL colony suppressor cells are Thy-1- and resistant to 1500 rad irradiation. These cells may play a role in maintenance of self tolerance. That they are found in FL as early as 13 days of gestation implies that potentially self-reactive cells may develop before experiencing the thymus environment.
Suppressive effect of human natural killer cells on pokeweed mitogen-induced B cell differentiation.
Authors: Arai S , Yamamoto H , Itoh K , Kumagai K
Published: December 2022

The suppressive effect of human natural killer (NK) cells on B cell differentiation induced by pokeweed mitogen (PWM) was investigated. By using Percoll discontinuous density gradient centrifugation, peripheral blood nonphagocytic and nonadherent mononuclear cells were divided into low and high density fractions for which NK cells (Large granular lymphocytes, LGL) and T cells were enriched, respectively. These fractionated mononuclear cells were co-cultured with purified autologous B cells in the presence of PWM, and were examined for their helper and suppressor activities on differentiation of B cells to immunoglobulin-(IgM and IgG) producing cells by a highly sensitive reversed hemolytic plaque assay. The T cell-enriched high density fractions provided help for B cell differentiation to levels higher than that of unfractionated mononuclear cells. On the other hand, the NK-enriched low density fractions did not show helper activity, and when added to the culture of B cells plus helper T cells, they markedly suppressed B cell differentiation. This suppressive activity, as well as the NK cytotoxicity of the NK-enriched fractions, was abrogated by treatment of the cells with monoclonal antibody against human NK cells (HNK-1), but not against T cells (OKT3) in the presence of complement. NK cells also suppressed PWM-driven B cell differentiation in the presence of T4+ (helper/inducer T) but not T8+ (cytotoxic/suppressor T) cells; however, they showed no inhibition of soluble factor-induced B cell differentiation assayed in the absence of helper T cells. It is thus concluded that human peripheral blood NK cells exhibit an ability to suppress PWM-driven B cell differentiation, possibly by acting through the effect on helper T cells but not directly on B cells.
Macrophage-activating factor produced by a T cell hybridoma: physiochemical and biosynthetic resemblance to gamma-interferon.
Authors: Schreiber R D , Pace J L , Russell S W , Altman A , Katz D H
Published: December 2022

Biochemical and biosynthetic evidence has been obtained which indicates that the macrophage activating factor (MAF) produced by the murine T cell hybridoma clone 24/G1, which primes macrophages for nonspecific tumoricidal activity, is a form of gamma-interferon (IFN gamma). MAF and antiviral activities were generated by the clone in proportional amounts under a variety of culture conditions. Production of both activities showed identical dependence on cell density even when production precipitously ceased at cell concentrations greater than 1.2 X 10(6) cells/ml. MAF and antiviral activities displayed identical sensitivities to pH and temperature and were indistinguishable on the basis of binding to insolubilized polynucleotides. Dye-ligand chromatography of a stimulated hybridoma supernatant on a column of Matrex Gel Red A resulted in the 1500-fold purification and 100% recovery of the MAF activity. A qualitatively identical elution profile was also obtained for the antiviral activity; however, only 32% of the original activity was recovered. When subjected to gel filtration on a high performance liquid chromatography system (HPLC), the MAF and antiviral activities present in the Matrex Red pool displayed identical elution profiles and exhibited an apparent m.w. of 50,000. This technique resulted in another 10-fold purification and 50% recovery of the two activities. On HPLC chromatofocusing the MAF activity in the Matrex Red pool could be resolved into seven chromatographically distinct species yet could not be resolved from the antiviral activity on either a qualitative or quantitative basis. These results thus provide quantitative molecular evidence to support the concept that IFN gamma can act as a MAF.
Regulation of the immune response to alloantigens: suppressor and helper T cells generated in the primary MLR of the rat.
Authors: Salomon D R , Cohen D J , Carpenter C B , Milford E L
Published: December 2022

The primary MLR of the rat was used to generate suppressor, cytotoxic, and helper T cells from lymph node cells of the WF (RT1 mu) inbred strain. They were assayed in 51Cr-release cytotoxic assays and by their effect on proliferation of fresh unprimed responder cells. Suppression by MLR cellular products was antigen-specific and generation and functional expression were directed to class II (RT1.B,D) antigens of stimulator cells in the strains tested. In contrast, help was not antigen-specific. The monoclonal antibodies OX8 and W3/25 were used to separate the primed products of the MLR into the constitutive subsets, suppressor/cytotoxic (OX8+) and helper/inducer (W3/25+). Gamma irradiation of OX8+ MLR-primed cells caused modest reductions in suppressive activity, but had no effect on the helper activity of W3/25+ cells. MLR-derived suppressor cells are effective only when added in the early stages of the test primary MLR, whereas helper cells can augment proliferation even when added late. Feedback suppression is not mediated by classical cytotoxic T cells, because of differences in kinetics of development, cell numbers required, susceptibility to freezing, and expression of the RT6 differentiation antigen.
Differentiation of human T lymphocytes. I. Acquisition of a novel human cell surface protein (p80) during normal intrathymic T cell maturation.
Authors: Haynes B F , Harden E A , Telen M J , Hemler M E , Strominger J L , Palker T J , Scearce R M , Eisenbarth G S
Published: December 2022

The thymus is thought to be the primary central lymphoid organ in which T cells mature. Although thymic cortical and medullary compartments are distinct histologically, few antigens have been described that are absolutely acquired during the presumed intrathymic maturation pathway from cortical to medullary thymocytes. In this paper, we describe the acquisition during human intrathymic T cell maturation of a novel protein (p80) defined by a monoclonal antibody (A1G3). Although the p80-A1G3 antigen is distributed throughout the body and is not T cell specific, our study demonstrates that expression of p80-A1G3 antigen in normal human thymus is associated with thymocyte functional maturity and location in the thymus medulla. Moreover, in contrast to other markers of mature human T cells, the p80-A1G3 cell surface protein is not expressed on T6+ cortical thymocytes, and, therefore, is absolutely acquired by medullary thymocytes during T cell maturation. Thus, the p80-A1G3 antigen and the A1G3 antibody provide a heretofore unavailable system for the study of molecular events that transpire during the maturation of thymocytes.
Prevention of cerebral malaria by adoptive transfer of malaria-specific cultured T cells into mice infected with Plasmodium berghei.
Authors: Finley R , Weintraub J , Louis J A , Engers H D , Zubler R , Lambert P H
Published: December 2022

Murine T cell populations specific for Plasmodium berghei parasites were generated in vitro from BALB/c immune lymph node cells. The malaria-specific T lymphocytes were shown: a) to proliferate specifically in vitro in response to stimulation with P. berghei-infected red blood cells; b) to exhibit the Thy-1+, Lyt-1+2- cell surface phenotype; c) to provide specific helper activity for an in vitro anti-hapten (TNP) plaque-forming cell antibody response; and d) to protect P. berghei-infected mice from early mortality due to cerebral malaria.
Production and characterization of monoclonal antibodies to human interleukin 2: strategy and tactics.
Authors: Smith K A , Favata M F , Oroszlan S
Published: December 2022

The unique hormonal characteristics of human interleukin 2 (IL 2), primarily the high affinity of the IL 2-receptor interaction, created several impediments to the generation of monoclonal antibodies to this lymphokine. Because normal cell sources produce only a few micrograms of IL 2 per liter, it was necessary to utilize high producer clones and subclones of a human T leukemia cell line to obtain immunogenic amounts of IL 2 protein. Moreover, assays that required antibody-mediated intervention of the high affinity IL 2-receptor binding were ineffectual in the identification of anti-IL 2-producing hybridomas, thus necessitating the development of immunoassays. Two of three initially derived antibodies detected by enzyme-linked immunoassay were found to react specifically with IL 2 as demonstrated by antibody concentration-dependent neutralization of IL 2 activity. The neutralization of cellular proliferation was specific for IL 2-reactive cells, coincided with an inhibition of IL 2 receptor binding, could be completely overcome by affinity-purified IL 2 and was species-specific; human and murine IL 2 were neutralized, whereas rat IL 2 activity remained unaffected. A third antibody, although much less effective in neutralizing IL 2 activity, bound to IL 2 more avidly and functioned as an efficient immunoabsorbent. IL 2 could be concentrated and purified by immunoabsorption from crude conditioned medium in a single step. The purified product, which retained biologic activity, was made up of a single protein (Mr = 15,500) as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis, reversed-phase liquid chromatography, and amino-terminal amino acid sequence analysis. These results indicate that the distinctive biochemical and functional properties of individual lymphokines may well determine the efficiency with which antibodies may be elicited and detected. However, once produced, anti-lymphokines are uniquely suited for the exploration of the molecular and biologic properties of these immunoregulatory molecules.
Heterogeneity of human mast cells.
Authors: Schulman E S , Kagey-Sobotka A , MacGlashan D W , Adkinson N F , Peters S P , Schleimer R P , Lichtenstein L M
Published: December 2022

Enzymatically dispersed human lung parenchymal cells were fractionated according to size by countercurrent centrifugation elutriation. Human lung mast cells eluted throughout the procedure indicating heterogeneity of mast cell diameters. In seven individual lung elutriations, the mean histamine content ranged from 2.5 +/- 0.5 pg/mast cell for the smallest diameter mast cells (8-10 microns) to 10 +/- 2.5 pg/mast cell for the largest (16-20 microns). Intermediate sized mast cells had correspondingly intermediate histamine contents. The maximum release of histamine after anti-IgE stimulation varied with mast cell size. Small mast cells consistently released less histamine (10 +/- 3.6% net) than the largest diameter mast cells (38 +/- 6% net). This differential histamine release could not be explained by cell surface IgE content which was similar in mast cells of all sizes. The concentration of anti-IgE for maximum histamine release was the same (2 micrograms/ml) for mast cells of all sizes. The generation of PGD2, the predominant cyclooxygenase metabolite of the human lung mast cell, also was correlated positively with mast cell size and to the quantity of histamine released. Studies to date indicate no clear pattern in agonist receptor activities as judged by the inhibition of histamine release by PgE2, the beta-adrenergic agonist, fenoterol, and adenosine. We conclude that human lung mast cells are heterogeneous with regard to size and function.
Activation of human monocyte cytotoxicity by natural and recombinant immune interferon.
Authors: Le J , Prensky W , Yip Y K , Chang Z , Hoffman T , Stevenson H C , Balazs I , Sadlik J R , Vilcek J
Published: December 2022

Human T cell hybridomas were established by fusion of SH9 cells, the 6-thioguanine-resistant mutant line of human T lymphoma Hut 102-B2, with concanavalin A-stimulated human peripheral blood lymphocytes. Hybridoma line L38 produced a macrophage activating factor (MAF) with the ability to activate human peripheral blood monocytes to show enhanced cytotoxicity against human colon adenocarcinoma HT-29 cells in a 72-hr 125iododeoxyuridine-release assay. The L38 line was then cloned by the limiting dilution technique and two sublines, L38B and L38D, were found to produce high levels of MAF constitutively. Interferon activity was also detected in L38B and L38D supernatants. When interferon activity was neutralized with specific antiserum to purified human immune interferon (IFN-gamma), MAF activity was abrogated. To confirm that the MAF activity is indeed due to IFN-gamma, IFN-gamma was purified from the culture supernatant of another human T cell hybridoma, L265K2, a cell line known to produce high levels of IFN-gamma. Two highly purified IFN-gamma fractions with m.w. of 20,000 and 25,000, respectively, were obtained by NaDodSO4/polyacrylamide gel electrophoresis (SDS-PAGE). Similar fractions were obtained from IFN-gamma derived from human peripheral blood lymphocyte (PBL) cultures induced with 12-0-tetradecanoylphorbol-13-acetate (TPA) and phytohemagglutinin (PHA). In comparison, Escherichia coli-derived recombinant human IFN-gamma separated by SDS-PAGE yielded two major active fractions with m.w. of 17,000 and 34,000. With all three types of preparations, a close correlation was found between the presence of IFN-gamma activity demonstrable in an antiviral assay and MAF activity in individual fractions. Substantial quantitative differences were observed in the ability of various human IFN to activate monocytes. Although no MAF activity was detected with IFN-alpha and IFN-beta at concentrations up to 200 U/ml, both natural and recombinant IFN-gamma showed marked MAF activity at concentrations as low as 0.3 to 1 U/ml.
Influence of RU 41.740, a glycoprotein extract from Klebsiella pneumoniae, on the murine immune system. I. T-independent polyclonal B cell activation.
Authors: Wood C D , Möller G
Published: December 2022

A glycoprotein extract from Klebsiella pneumoniae, RU 41.740, has been shown clinically to reduce infectious episodes in patients prone to frequent infections, and experimentally to reduce mortality in animals infected with various bacteria or viruses. The method of action of RU 41.740 in conferring protection from infection is as yet unknown, but in experimental animals, RU 41.740 appears to influence B and T cells as well as macrophages. We report here that RU 41.740 is a strong polyclonal B cell activator and that it activates B cells in a T-independent manner. RU 41.740 also activates spleen cells from the LPS-nonresponder mouse strains, C3H/HeJ and C57BL/10ScCr, which indicates that the polyclonal B cell activating ability of RU 41.740 is not due to contamination by LPS.
Modulation of human B cell immunoglobulin secretion by the C3b component of complement.
Authors: Tsokos G C , Berger M , Balow J E
Published: December 2022

The human C3b component of complement was found to inhibit the differentiation of human B lymphocytes into immunoglobulin-secreting cells in vitro. Pokeweed mitogen (PWM)-induced plaque-forming cell (PFC) responses were inhibited by C3-coated zymosan particles and by purified human C3b. C3b inhibited the PWM-driven responses in a dose-dependent fashion, and it was necessary for C3b to be present in the early phases of the cultures. C3b acted directly on B cells rather than on helper T cells because it inhibited the PFC responses of MNC depleted of T cells and subsequently stimulated with a T cell-independent Epstein Barr virus mitogen. Furthermore, C3b failed to stimulate the generation of suppressor lymphocytes and/or monocytes that might have been responsible for the inhibition of B cell responses. Our results indicate that C3b or its fragments exert negative modulatory effects on human B lymphocyte responses.
Comparison of antigen-specific T cell responses in autoimmune MRL/Mp-lpr/lpr and MRL/Mp-+/+ mice.
Authors: Scott C F , Tsurufuji M , Lu C Y , Finberg R , Sy M S
Published: December 2022

The MRL-1 mouse develops severe autoimmune disease characterized by high titers of autoantibodies at an early age (3 to 5 mo). The congeneic MRL-n mouse, which differs only in the lymphoproliferative (lpr) gene, exhibits no such pathologic or serologic abnormalities at the same age. We examined antigen-specific T cell responses in the MRL-1 mouse and compared them to age- and sex-matched MRL-n controls. We found broad defects in these responses in the MRL-1 mouse; an inability to generate primary allospecific and hapten-specific cytolytic T lymphocytes (CTL), secondary hapten- and virus-specific CTL, as well as a deficient proliferative response to hapten and natural antigens and a weak delayed-type hypersensitivity response were demonstrated. Our data furthermore suggest a lack of interleukin 2 (IL 2) acceptor sites in the proliferating T cell, while suggesting no such lack on CTL precursors. In fact, the deficient CTL responses in MRL-1 mice can be restored to levels seen in MRL-n by the in vitro addition of IL 2. The implications of these findings and the possible explanations for the relative deficit in helper function in the MRL-1 mouse are discussed.
Interferon and natural killing of human lymphoma cell lines after induction of the Epstein Barr viral cycle by superinfection.
Authors: Blazar B A , Strome M , Schooley R
Published: December 2022

Interferon (IFN) production during natural killer (NK) cell assays with Raji, an EBV-carrying human lymphoma-derived cell line, was studied to determine whether IFN generated by effectors in vitro acted in target cell lysis. In 4-hr tests, Raji is insensitive to NK but becomes susceptible after superinfection with the P3HR-1 strain of EBV. IFN was not detectable by bioassay in supernatants from 4-hr assays, and the addition of antibody to IFN did not prevent the lysis of the superinfected Raji cells. In 18-hr tests the NK sensitivity of the superinfected Raji cells was markedly elevated, and a percent of the normal Raji cells was also killed. IFN alpha was found in supernatants from 18-hr tests. Antibody to IFN alpha markedly reduced the killing of superinfected Raji and slightly reduced cytotoxicity against control Raji in 18-hr tests. Taken together these results indicate that what is referred to as natural killing has IFN-related and IFN-nonrelated components.
Replication of herpes simplex virus in human T lymphocytes: characterization of the viral target cell.
Authors: Braun R W , Teute H K , Kirchner H , Munk K
Published: December 2022

Herpes simplex virus (HSV) replicated in mitogen-stimulated human T cells. Virus replication was obtained in highly enriched mitogen-stimulated T cells of the OKT 3+, OKT 4+, or OKT 8+ subtype, in stimulated B cells, and in macrophages precultured for 7 days. In contrast, no virus replication was obtained in unstimulated T or B cells, in macrophages grown in culture for 1 day, in Null/NK cells, or in granulocytes. Infectious center assays revealed that below 1% of the infected T cell subpopulations supported virus replication, whereas up to 42% of infected B cells and 80% of macrophages cultured for 1 wk were able to replicate HSV. By indirect double immunofluorescence studies, complement-mediated mass cytolysis, and positive selection experiments, it was shown that only T cells expressing Ia antigen actively replicated the virus. T cells activated in the mixed lymphocyte culture and with UV-inactivated HSV were also susceptible to HSV infection. Several human leukocyte cell lines were tested for their ability to support virus replication and were tested for a correlation with the expression of Ia antigen. Only cell lines expressing Ia antigen on more than about 5% of the total population produced new progeny virus. Ia-expressing T cells that spontaneously replicated HSV without any mitogenic prestimulation were found to occur in variable numbers in human cord blood. It is suggested, that such T cells, permissive for HSV replication, might contribute to an outspread of viral infection in vivo.
Mechanisms of contact photosensitivity in mice. IV. Antigen-specific suppressor T cells induced by preirradiation of photosensitizing site to UVB.
Authors: Takigawa M , Miyachi Y , Toda K , Yoshioka A
Published: December 2022

Mice were successfully contact photosensitized with 3,3',4',5-tetrachlorosalicylanilide (TCSA) plus black light irradiation. Pre-exposure of the photosensitizing site (ca 5 cm2) to UVB (280 to 320 nm; 400 mJ/cm2) rendered mice unresponsive to a challenge reaction. Cell transfer experiments demonstrated that the spleens from the nonreactive mice contained suppressor T cells (Ts) that were antigen-specific and that blocked the afferent limb of contact photosensitivity to TCSA. To exert suppressive functions, Ts required another population of cyclophosphamide-sensitive T cells that resided in the spleens of nonsensitized mice. The results provide evidence that UVB-induced aberrant homeostasis of the skin caused a marked suppression of immune system that is associated with the generation of Ts.
T cell regulation of B cell activation: MHC-restricted T augmenting cells enhance the B cell responses mediated by MHC-restricted cloned T helper cells.
Authors: Asano Y , Hodes R J
Published: December 2022

The present studies demonstrated that unprimed populations of Lyt-1+2- T cells are able to augment the responses generated by optimal numbers of antigen-specific and MHC-restricted cloned TH cells. The TA cells function early in the course of B cell responses. Responses mediated by (A X B)F1 (B + accessory) cells and parentA restricted cloned TH cells are augmented by TA cells from (A X B)F1 leads to parentA radiation bone marrow chimeras, but not by TA cells from (A X B)F1 leads to parentB chimeras. Thus, TA cell activation and function are MHC-restricted, but this restriction is not related to recognition of genotypically expressed B cell and/or accessory cell MHC products alone. Rather, TA cell function is intimately related to the MHC-restricted interaction between TH cells and responding (B + accessory) cells. Specifically, it was shown that TH cell interaction with B cells via an MHC-restricted and carrier-hapten-linked pathway is required for the function of TA cells expressing the same MHC restriction. Moreover, neither MHC homology nor TH cell recognition of MHC determinants on TA cells is required for TA cell function, and the activity of TA cells is not demonstrably influenced by non-MHC genes. It was further demonstrated that the function of cloned TH cells in B cell activation consists of at least two distinct components, one is radiosensitive and the other is radioresistant. TA cells are able either to replace the radiosensitive function of cloned TH cells directly or to bypass this requirement through an alternative pathway.