bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of mitogen-induced proliferation of mouse T and B lymphocytes by bloodstream forms of Trypanosoma cruzi.
Authors: Maleckar J R , Kierszenbaum F
Published: December 2022

The role of virulent forms of Trypanosoma cruzi in modulating mitogen-induced lymphocyte responses was investigated in this work. Bloodstream forms of T. cruzi inhibited normal mouse spleen cell responses to Con A and LPS in a dose-dependent manner. Reduced responses were observed over relatively large ranges of concentration of Con A (50-fold) and LPS (160-fold). The inhibitory action of the parasites could not be overcome by increasing the mitogen dose beyond optimal levels. Furthermore, absorption of mitogen solutions with four times as many parasites as used in the proliferation assays revealed that sufficient mitogen activity remained to produce optimal lymphocyte responses. Therefore, reduced lymphocyte responsiveness was not due to absorption of mitogen by the parasite. Inhibited responses were also seen when a sonicated T. cruzi preparation was used, indicating that parasite viability was not required to produce suppression. Inhibition of Con A- or LPS-induced responses by the parasites occurred only when the trypanosomes were incorporated into the system during the first 24 hr of culture. These results show that virulent forms of T. cruzi can induce suppression of T and B cell responses in vitro, and suggest that the parasite affects lymphocyte commitment to blastogenesis during the early stages of lymphocyte activation.
5-halo-6-phenyl pyrimidinones: new molecules with cancer therapeutic potential and interferon-inducing capacity are strong inducers of murine natural killer cells.
Authors: Lotzová E , Savary C A , Stringfellow D A
Published: December 2022

We tested the effect of three different interferon-(IFN) inducing pyrimidinone molecules with cancer therapeutic potential on natural killer (NK) cells. Peritoneal exudate (PE) cells were selected for these studies because their NK cell cytotoxicity is very low. Augmentation of PE-NK cell cytotoxicity was observed in eight different strains of mice after i.p. administration of 250 mg/kg of each of the pyrimidinones. NK cell induction occurred as early as 6 hr after pyrimidinone administration and peaked 2 to 4 days after treatment; at that time, cytotoxicity was as high as 60 to 90%. Augmentation of NK cell activity was independent of IFN serum levels induced by pyrimidinones and murine H-2 haplotype, and did not exhibit any histocompatibility or species-specific restriction, because it was expressed to syngeneic, allogeneic, and xenogeneic tumor target cells. Characterization studies demonstrated that the cytolytic cells were not macrophages, T cells, or B cells and exhibited NK cell characteristics. NK cell tumor-binding and tumor-killing studies demonstrated that NK cell augmentation was accomplished via both activation and recruitment of NK cells. If one considers NK cells as an important part of tumor immunity (as indicated by murine studies), pyrimidinone molecules may be effective anticancer agents.
Macrophage cell cycling: influence on Fc receptors and antibody-dependent phagocytosis.
Authors: Gandour D M , Walker W S
Published: December 2022

The influence of cell cycling on the density and binding properties of IgG2a Fc receptors and their associated antibody-dependent phagocytic activity was investigated with the P388D1 murine macrophage cell line. Unseparated macrophages and subpopulations of elutriated macrophages, enriched for cells in G1, S, and G2 + M phases were compared to detect possible differences in IgG2a-dependent phagocytosis. Suspensions of G2 + M phase cells were appreciably enhanced in phagocytic activity over G1-phase cells, which were less phagocytic than unseparated macrophage populations. An analysis of the binding of 125I-IgG2a myeloma protein disclosed that the IgG2a Fc receptor avidity remained essentially unchanged during cell cycle traverse, whereas the number of IgG2a Fc receptors more than doubled as cells cycled from G1 to G2 + M (1.5 X 10(5) vs 3.4 X 10(5) receptors per cell). With their increased size relative to G1 cells, and the resultant increase in receptor number, G2 phase cells should have more productive collisions with the antibody-coated target cells and greater phagocytic capacity.
Alveolar macrophages in pulmonary immune responses. I. Role in the initiation of primary immune responses and in the selective recruitment of T lymphocytes to the lung.
Authors: Lyons C R , Lipscomb M F
Published: December 2022

Antigen inoculated intratracheally (IT) into animals can induce primary immune responses and selectively recruit specific T cells to the lung. In the current study, the role of alveolar macrophages (AM) in these two responses was investigated. Antigen-pulsed bronchoalveolar cells (BAC) inoculated IT into guinea pigs generated a population of immune T cells that proliferated in vitro on reexposure to antigen-pulsed macrophages (Mø). The possibility that antigen-pulsed donor BAC shed antigen that was subsequently processed and presented by host Mø was ruled out by genetic experiments. Thus, peritoneal exudate lymphocytes (PEL) from (2 X 13)F1 guinea pigs primed with antigen-pulsed BAC from strain 2 animals responded preferentially to antigen-pulsed strain 2 Mø rather than to antigen-pulsed strain 13 Mø. In a second set of studies, antigen-pulsed BAC inoculated IT into guinea pigs selectively recruited antigen-specific T cells to the lung. Genetic experiments verified that inoculated BAC were the source of the antigen-presenting cells responsible for selective recruitment. Thus, antigen-pulsed strain 2 BAC inoculated IT recruited a greater proportion of (2 X 13)F1 T cells that recognized antigen in the context of strain 2 Mø than F1 T cells that recognized antigen on strain 13 Mø. Taken together, these studies suggest that AM contribute to the regulation of pulmonary immunity by both inducing T lymphocyte immunity and selectively recruiting specific T cells to the lung.
Inhibition of interleukin synthesis and T cell proliferation by a monoclonal anti-Ia antibody.
Authors: Gilman S C , Rosenberg J S , Feldman J D
Published: December 2022

The proliferative response in vitro of Lewis rat spleen cells to Con A was inhibited by a monoclonal antibody, OX4, with specificity for a public rat la antigen. Inhibition was dose-dependent and was observed only if the antibody was present during the first 48 hr of culture. OX4 anti-la antibody inhibited production of IL 1 by peritoneal exudate cells activated by lipopolysaccharide and inhibited the production of IL 2 by spleen cells activated by Con A. Addition of exogenous IL 1 to spleen cell cultures inhibited by OX4 anti-la antibody augmented production of IL 2 and returned the proliferative response of T cells to levels observed in Con A-stimulated cultures. We suggest that OX4 anti-la antibody reacts with la+ accessory cells to inhibit production of IL 1, which in turn limits production of IL 2 and finally T cell proliferation.
Fibroblast stimulation in schistosomiasis. IV. Isolated egg granulomas elaborate a fibroblast chemoattractant in vitro.
Authors: Wyler D J , Postlethwaite A E
Published: December 2022

Hepatic fibrosis complicates the chronic granulomatous inflammatory reaction to Schistosoma mansoni eggs, and is the major cause of morbidity and mortality in human schistosomiasis. We previously presented evidence that schistosomal egg granulomas secreted factors that can stimulate fibroblast proliferation and collagen synthesis in vitro. We now report that serum-free supernatants from cultures of hepatic egg granulomas isolated from S. mansoni-infected mice contained activity that stimulated the directional migration of human and guinea pig dermal fibroblasts in modified Boyden chambers. This fibroblast chemotactic activity was also detected in culture supernatants of granuloma adherent cells highly enriched for macrophages (95% latex-ingesting) but not in culture supernatants from resident peritoneal macrophages of uninfected or infected mice. This suggests that granuloma macrophages are a source of the chemotactic activity. The chemoattractant had the properties of large molecular weight (greater than 200,000 daltons; Sephadex G-200 gel filtration), pl approximately 4.5 (preparative flatbed isoelectrofocusing in granular matrix), heat stability (56 degrees C; 45 min), and trypsin sensitivity. Since preincubation of the partially purified granuloma and adherent-cell derived chemoattractants with rabbit anti-human fibronectin antibody abolished their chemotactic activity, it appears that the factor is antigenically similar to fibronectin. We propose that egg granuloma macrophages are activated in vivo to secrete a fibronectin-like molecule with activity that stimulates the directional migration of fibroblasts. This factor may therefore play a role in the local recruitment of fibroblasts and, in concert with other granuloma-derived factors, may play an important role in the pathogenesis of hepatic fibrosis in schistosomiasis.
Cytotoxic T lymphocytes reactive with vesicular stomatitis virus: analysis of specificity with monoclonal antibodies directed to the viral glycoprotein.
Authors: Lefrancois L , Lyles D S
Published: December 2022

A panel of monoclonal antibodies (MAb) reactive with the vesicular stomatitis virus (VSV) glycoprotein (G-protein) was used to inhibit lysis of infected target cells by cytotoxic T lymphocytes (CTL) reactive with VSV serotypes Indiana and New Jersey (VSV-Ind, VSV-NJ). MAb to distinct epitopes on the VSV-NJ G-protein were able to block lysis of VSV-NJ-infected targets using anti-VSV-NJ CTL. Furthermore, when a combination of MAb to three distinct epitopes was used, increased inhibition was observed when compared to single epitope blocking. Cross-reactive CTL generated using either VSV-NJ or VSV-Ind could be inhibited by MAb specific for the heterologous virus in blocking assays. Cross-reactive MAb also were able to block both serotype-specific and cross-reactive lysis. Antigenic variants selected with some of the MAb used in blocking studies were used to infect target cells. Reduction in lysis was not observed using variants with mutations at several epitopes. This result suggests that blocking by MAb involves steric hindrance of CTL-recognized determinants proximal to the MAb binding site.
Antigenic heterogeneity of surgically removed primary and autologous metastatic human melanoma lesions.
Authors: Natali P G , Cavaliere R , Bigotti A , Nicotra M R , Russo C , Ng A K , Giacomini P , Ferrone S
Published: December 2022

The antigenic heterogeneity of primary and metastatic lesions surgically removed from nine patients with nodular melanoma was investigated by using monoclonal antibodies to HLA-A, B antigens, to beta 2-microglobulin, to Ia antigens, and to melanoma-associated antigens (MAA). The latter include three types of membrane-bound MAA and a cytoplasmic MAA. In spite of an homogeneous morphologic appearance, multiple lesions removed from the same patient differed significantly in their reactivity with the panel of monoclonal antibodies in indirect immunofluorescence test. The extent of antigenic heterogeneity did not correlate with melanin synthesis, site of origin of the primary tumor, site of metastatic foci, or treatment, but was less marked in patients carrying the primary tumor. The antigenic heterogeneity of multiple lesions removed from one patient and the independent expression of the various types of MAA investigated suggest that combinations of monoclonal antibodies to MAA may be more effective than single antibodies for radioimaging and immunotherapy.
Photoimmunotherapy: treatment of animal tumors with tumor-specific monoclonal antibody-hematoporphyrin conjugates.
Authors: Mew D , Wat C K , Towers G H , Levy J G
Published: December 2022

The term "photoimmunotherapy" describes an anti-cancer treatment that combines the phototoxic effects of chemical such as hematoporphyrin and the target-seeking ability of antibodies. Hematoporphyrin was chemically coupled to monoclonal antibodies directed to the DBA/2J myosarcoma M-1. Administration of anti-M-1-hematoporphyrin conjugates i.v. to M-1 tumor-bearing animals followed by exposure to incandescent light resulted in suppression of M-1 growth. The time interval between injection and light exposure was an important parameter in terms of tumor suppression. Tumor-bearing animals maintained in the dark for 96 to 196 hr after hematoporphyrin-antibody injection followed by 4-hr light exposure demonstrated significantly lower tumor incidence and longer latency periods, in comparison to conjugate-treated animals instantly exposed to light. The growth inhibiting properties of the conjugate appeared to be M-1-specific; it had no effect on the growth of a C57BL/6J lymphoma EL4. In addition, conjugates made with a nonspecific monoclonal antibody did not have any specific anti-tumor effect on M-1 growth. Treatment with equivalent doses of hematoporphyrin or antibody had no significant inhibiting effect on tumor growth. Clearly, the homing ability of the specific monoclonal antibody-hematoporphyrin conjugate was essential for effective drug delivery and inhibition of tumor growth.
Autoimmune effector cells. V.A monoclonal antibody specific for rat helper T lymphocytes inhibits adoptive transfer of autoimmune encephalomyelitis.
Authors: Swanborg R H
Published: December 2022

The in vitro activation of spleen cells from donor rats immunized with myelin basic protein results in enhanced adoptive transfer of experimental allergic encephalomyelitis to syngeneic recipients. In this study, adoptive transfer was inhibited when monoclonal antibody W3/25, which defines an antigen on rat helper T lymphocytes, was included in the in vitro cultures. Partial inhibition was achieved with monoclonal antibody OX-3, which recognizes la antigen, whereas other anti-T cell monoclonal reagents were ineffective. These results support the conclusion that W3/25+T cells play an essential role in the induction of this autoimmune response.
A requirement for helper T cells in the induction of delayed-type hypersensitivity.
Authors: Wright K , Ramshaw I A
Published: December 2022

This paper describes a model system for studying the role of helper T cells in the induction of delayed-type hypersensitivity (DTH). Cyclophosphamide- (CP) treated mice sensitized with antigen 3 days later develop high levels of delayed-type immunity; however, DTH cannot be demonstrated in mice that are sensitized with antigen 1 day after drug treatment. The inability to respond to antigen 1 day after CP treatment can be restored if either normal or low-dose primed spleen cells are transferred at the time of sensitization. Although irradiated (1500 rad) normal spleen cells are unable to restore DTH, such treatment has no effect on the primed spleen cell population. The lymphocytes responsible for restoring the DTH response were identified as T cells, in that treatment with anti-Thy-1.2 serum and C abrogated their effect. Furthermore, restoration of the DTH response was dependent on the presence of antigen at the time of lymphocyte transfer; irradiated primed cells could not transfer DTH alone. The DTH effector cells in reconstituted mice were identified as originating from the host and not from the transferred cell population. This was accomplished by using anti-H-2 serum to identify the source of the DTH effector cells after transferring parental (H-2b) irradiated primed spleen cells into CP-treated F1 mice (H-2b,k). Thus, the irradiated transferred cells are behaving as helper T cells and promoting the development of DTH effector cells in the host.
Effect of fractional cyclophosphamide dosage on sheep red blood cell-delayed-type hypersensitivity response in mice.
Authors: Rondinone S N , Giovanniello O A , Barrios H A , Nota N R
Published: December 2022

The CY-enhancing effect on DTH response of mice against SRBC was studied by administering to sensitized animals graded amounts of drug at various times during the immune response. The use of a staggered schedule for CY administration made it clear that this enhancing effect could be augmented even further by lowering the standard 200 mg/kg CY dose. Animals immunized on day 0 with 1 X 10(8) SRBC receiving 50 mg/kg doses on days -1, +1, and +4 showed higher DTH responses on day +7 than those similarly sensitized 1 day after the administration of 200 mg/kg body weight. In addition, we wanted to demonstrate that the TDTH effector cell is sensitive to CY in vivo, because a single 50 mg/kg dose inoculated on day +6 can lower by 50% an already established DTH response. This effect was not due to an effect of CY treatment on bone marrow-derived cells recruited to DTH responses; inhibition of DTH responses were transferred with spleen cells of CY-treated recipients. The action of CY is not dose-dependent; the administration on day +6 of a single dose of 200 mg/kg results in no further depression of the DTH reaction. We conclude that CY affects not only T supp cells, but also cell type(s) involved in the cell-mediated response of mice against SRBC, and that the DTH-enhancing effect of the drug is a blend of its action upon all these cells.
Clonal proliferation unlinked to terminal deoxynucleotidyl transferase synthesis in thymocytes of young mice.
Authors: Rothenberg E , Triglia D
Published: December 2022

Terminal deoxynucleotidyl transferase (TdT) is a specialized DNA polymerase that is potentially mutagenic. It is expressed only in the thymus and in some bone marrow cells, suggesting that it acts selectively in immature lymphoid cells, especially T cells. We investigated the extent to which de novo synthesis of TdT is correlated with the clonal expansion that T cell precursors undergo in the thymus. Using biosynthetic pulse-labeling and immune precipitation, we found that thymocytes from late-fetal and neonatal mice make TdT at considerably lower levels than weanling or adult mouse thymocytes. Adult levels of TdT synthesis are only reached a week after birth. Thus, the high proportion of proliferating cells in the perinatal thymus does not entail a correspondingly high production' of TdT synthesis is blocked by cytolytic treatment with anti-Lyt-2 and complement, suggesting that the inducible cells are already Lyt-2+ like most adult TdT+ thymocytes. These observations imply that the stroma of the perinatal thymus either suppresses or fails to trigger high-level TdT synthesis. At the same time, it is in this microenvironment that maximum proliferation and export of functional T cell precursors take place. In contrast, the conditions that stimulate high TdT synthesis in vitro are not associated with mitogenesis but rather with growth arrest. High-level TdT synthesis in general is not regulated so as to precede or coincide with clonal expansion, either in perinatal or in adult thymocyte populations. The possibility remains that in many cells it is linked with a commitment to die.
Patterns of isotype commitment in human B cells: limiting dilution analysis of Epstein Barr virus-infected cells.
Authors: Stein L D , Ledgley C J , Sigal N H
Published: December 2022

The frequency of Epstein Barr virus- (EBV) inducible IgM, IgG, and IgA-secreting cells in human peripheral blood and tonsil was determined by performing limiting dilution experiments in suspension culture. We devised a method of propagating small numbers of EBV-infected B cells with irradiated umbilical cord blood cells as a feeder layer. Precursor cell frequencies can be derived from these experiments; we have shown by statistical analysis that they conform to the single hit model of the Poisson distribution. By using this technique, a significant percentage of surface immunoglobulin-bearing lymphocytes are activated to secrete immunoglobulin in vitro. On the average, 8 to 38% of B cells in peripheral blood and tonsil can be propagated and the secreted immunoglobulin from the clonal progeny can be analyzed. Neither the EBV immune status of the donor nor the source of the umbilical cord blood feeder layer could account for the variations in cloning efficiency observed among donors. A surprisingly high frequency of B cells secreted IgA in vitro and we have shown that a small proportion of B cell clones in tonsil and peripheral blood secrete both IgM and IgA during the 4-wk culture period. Other B cells, including all those that produce IgG, appear to be committed to the secretion of a single isotype. Thus, these studies establish methodology for the analysis of the secreted products of human B cells at the single cell level and demonstrate that the progeny of at least some clones can secrete more than one isotype in vitro.
Permeability of the blood cerebrospinal fluid barrier during acute immune complex disease.
Authors: Hoffman S A , Arbogast D N , Day T T , Shucard D W , Harbeck R J
Published: December 2022

Changes in the permeability of the blood-brain barrier (BBB) and blood-cerebrospinal fluid (blood-CSF) barrier in rabbits were assessed by using a sensitive double isotope technique at different times after the induction of acute immune complex disease (AICD). Induction of AICD was done with a single large dose of bovine serum albumin, whereas controls received only saline. Animals were sacrificed 6, 9, 12, 15, and 18 days after induction. Extravasation of protein was measured by injecting rabbits i.v. with 131I-rabbit serum albumin (RSA) 24 hr before sacrifice. In order to correct for intravascular blood volume, 125I-RSA was injected 5 min before sacrifice. Extravascular blood equivalents (EVBE), a measure of barrier permeability, were elevated in the CSF of rabbits sacrificed on days 12 and 15. None of the brain regions from any of the animal groups showed any changes or significant differences from controls in EVBE values on these days. These results indicate that there was an increase in the permeability of the blood-CSF barrier to radiolabeled albumin but not in the BBB proper during the time that CSF IgG levels were elevated in AICD. The potential significance of these findings for the mechanisms mediating central nervous system involvement in systemic lupus erythematosus is discussed.
Impaired immunoregulation in systemic lupus erythematosus: defective adenosine-induced suppressor T lymphocyte generation.
Authors: Kammer G M , Birch R E , Polmar S H
Published: December 2022

It is currently unclear whether the suppressor cell dysfunction observed during active systemic lupus erythematosus (SLE) reflects a primary T cell disorder or one that results from immunologic modulation of suppressor T cell activity by autoantibodies. To determine whether the suppressor T cell dysfunction of active SLE is the result of a primary T cell disorder, the model of adenosine-induced immunosuppression was utilized to study the suppressor T cell functions of 12 patients with SLE (seven active SLE, five inactive SLE) and 12 matched healthy controls. T lymphocyte phenotyping was performed by utilizing monoclonal antibodies directed against T cell-specific determinants. Suppressor T cell functions were assessed by two assays in parallel. The first technique tested the capacity of two suppressor T cell subsets (spontaneous suppressors, Ts; adenosine-inducible suppressors, TRA) to inhibit pokeweed mitogen- (PWM) induced B cell differentiation. In the second technique, the ability of enriched T cell preparations to suppress mitogen- and alloantigen-induced proliferation was assayed. It was demonstrated that brief treatment of the control theophylline-resistant T lymphocyte (TR) subset possessing inducer/helper activity with adenosine (10(-5) M, 30 min, 37 degrees C) triggered a rapid shift in phenotype (RFC gamma -, T-4+ leads to RFC gamma +, T-8+) in a proportion of the subset, and the development of radioresistant suppressor function. By contrast, exposure of active SLE TR to adenosine failed to induce either the switch of phenotype or suppressor activity. When compared to controls, both the TS and TRA suppressors failed to inhibit B cell differentiation (TS, p less than 0.001; TRA, p less than 0.001). Moreover, enriched T cell preparations incompletely suppressed the proliferative responses to phytohemagglutinin (p less than 0.003), PWM (p less than 0.0003), or alloantigens (p less than 0.01). During inactive SLE, the T cell responses were usually restored. Treatment of the TR subsets with adenosine induced a switch of phenotype in four of five patients and the subsequent expression of effective suppressor function. We conclude that a) during active SLE, there is impaired suppression of proliferation and B cell differentiation; b) the impaired suppression of B cell differentiation results from abnormal spontaneous (TS) and adenosine-inducible (TRA) suppressor functions; c) the defective generation of suppressor T cell function during active disease results, in part, from a block in the transition from inducer/helper to suppressor cell; and, d) the suppressor T cell dysfunction is reversible with disease remission. The investigation of immunopharmacologic events by using the adenosine-induced immuno-suppression model in T cells from normal donors and SLE patients may provide insights into the molecular basis of disordered immunoregulation in SLE.
Genetic control of low-dose streptozotocin-induced autoimmune diabetes in mice.
Authors: Kiesel U , Falkenberg F W , Kolb H
Published: December 2022

Multiple treatment with low doses of streptozotocin induces in mice an experimental autoimmune diabetes characterized by hyperglycemia and lymphocytic infiltrations of pancreatic islets. We have studied the genetic control of the disease. Low-dose streptozotocin treatment was performed in mice of H-2 congenic strains on B10, C3H, or A background. Blood glucose concentrations were followed up to 100 days. Among the various B10 and C3H strains, significant differences in the development of diabetes (hyperglycemia) are noted demonstrating that genes within the H-2 complex influence the susceptibility to the diabetogenic effect of low-dose streptozotocin treatment. The congenic mouse strains on A background did not differ significantly in the diabetic response to streptozotocin. The analysis of B10 recombinant strains shows that genes coding for susceptibility are located in the centromeric (left) side of the H-2 complex. Evidence for an additional role of non-H-2 genes is given by comparison of mouse strains carrying the same H-2 haplotype on different genetic background genomes: B10.S (H-2s), B10.S(7R) (H-2t2), and C3H.SW (H-2b) are resistant to the diabetic effect of low-dose streptozotocin treatment, whereas A.SW (H-2s), A.TH (H-2t2) and B10 (H-2b) are susceptible to diabetes development.
Spontaneous diabetes mellitus syndrome in the rat. II. T lymphopenia and its association with clinical disease and pancreatic lymphocytic infiltration.
Authors: Guttmann R D , Colle E , Michel F , Seemayer T
Published: December 2022

We have studied the occurrence of two phenotypic components (pancreatic lymphocytic infiltration [PLI] of the pancreas and T lymphocytopenia) of the spontaneous insulin-dependent diabetic syndrome (IDDM) in the progeny of hybrids obtained by crossing BB diabetic rats with rats of inbred strains differing from the BB rat at the major histocompatibility complex, RT1. Both PLI and T lymphopenia were seen in animals with all three possible genotypes in both (BUF x BB) and (LEW x BB) lines. PLI was seen in all IDDM animals. T lymphopenia was strongly associated with overt IDDM in both lines (chi 2 = 22.28, p = 0.00002 and chi 2 = 19.28, p less than 0.00001). In addition, T lymphopenia was associated with PLI with and without IDDM in both lines (chi 2 = 8.32, p = 0.0039 an chi 2 = 3.95, p = 0.0467). Not all animals exhibiting PLI without overt IDDM had depressed T cells. Not all animals with T lymphopenia had PLI with or without IDDM. In both lines, the overt IDDM occurred only in animals with at least one RT1 u haplotype derived from the BB rat, confirming our previously reported association of IDDM and RT1. We interpret this evidence to suggest that the overt IDDM syndrome requires one MHC-linked gene and at least two non-MHC-linked genes, which determine susceptibility to PLI and to circulating T lymphocyte depression.
Analysis of cellular events involved in T cell stimulation by concanavalin A as a function of cell concentration.
Authors: Akiyama H , Kumagal J , Yahara I
Published: December 2022

To investigate cell-to-cell interactions in T cell stimulation by concanavalin A (Con A), three distinct events involved in the stimulation--production of interleukin 2 (IL 2), emergence of IL 2 receptors, and responses of cells bearing IL 2 receptors to IL 2--have been separately determined as functions of the cell concentration. Results obtained at concentrations as low as 5 X 10(4) cells/ml showed that both the emergence of IL 2 receptors and the induction of DNA synthesis by IL 2 of lymphocytes bearing IL 2 receptors occurred in a manner independent of the concentration of cells, whereas the production of IL 2 depended greatly on the cell density. These results suggest that the production of IL 2 requires cell-to-cell interactions, but the other two events do not.
Idiotypes on B lymphocytes: association with immunoglobulins.
Authors: Victor C , Bona C , Pernis B
Published: December 2022

Several idiotypic (Id) specificities have been identified by immunofluorescence on the membranes of B cells in the spleens of nonimmune mice. These determinants are displayed at frequencies varying from 0.22 to 1.83% of B cells and are entirely immunoglobulin (Ig) in nature. No Id determinants were observed on the membranes of four Slg- Abelson virus-transformed pre-B cell lines that are sensitive to LPS. Under our experimental conditions, we did not observe a significant increase in 3H-thymidine incorporation subsequent to the in vitro incubation of splenic lymphocytes from normal mice with various amounts of anti-Id antibodies specific for several cross-reactive (IdX) or individual Id. Similarly, in utero exposure to anti-Id antibodies against myeloma proteins specific for T-independent antigens displaying B cell mitogenic properties did not alter the proliferation of lymphocytes induced by these mitogens. In contrast, exposure to anti-Id antibodies in vitro as well as in utero had a profound and specific effect on the corresponding antibody responses and maturation of small lymphocytes into plasma cells. When normal B cells were cultured with the B cell mitogen LPS in the presence of anti-Id antibodies directed against the J558IdX, specific suppression of the maturation of IdX+ plasma cells was observed. In mice exposed to maternal anti-Id in utero, we observed a severe inability to mount an immune response to any compound that elicited antibody molecules bearing the Id that was complementary to the maternal anti-Id. These same maternally Id-suppressed mice, however, gave a normal response when the same compound was presented as a mitogen. Our results reinforce the concept that Id on membranes of B lymphocytes are associated only with Ig receptors and do not support the possibility of mitogen-like poly-clonal stimulatory properties of anti-Id antibodies.
Comparative structural analysis of HLA-A2 antigens distinguishable by cytotoxic T lymphocytes. II. Variant DK1: evidence for a discrete CTL recognition region.
Authors: Krangel M S , Biddison W E , Strominger J L
Published: December 2022

Multiple amino acid sequence differences distinguish individual HLA antigens. Those residues important in immune recognition events have not been defined. Recent studies have identified HLA-A2 structural variants that, although serologically indistinguishable from other HLA-A2 antigens, are recognized poorly, if at all, by HLA-A2-restricted, influenza virus-immune, or HLA-A2-specific alloimmune CTL. In this study we utilize double-label tryptic peptide comparisons performed by both reverse-phase HPLC and cation exchange chromatography, in conjunction with conventional and microsequence analysis, to characterize the HLA-A2 heavy chains derived from variant DK1. We detect a single tryptic peptide that distinguishes DK1 HLA-A2 from the predominant HLA-A2 heavy chain species. This peptide spans residues 147 to 157 in the second heavy chain domain, and carries substitutions at positions 149, 152, and 156. Residues in this segment of the polypeptide are also altered in another HLA-A2 variant, as well as one H-2Kb mutant. Thus, this segment appears to be critical in forming determinants important in CTL recognition of class I antigens in general. On the basis of these and other results, we suggest that in contrast to recognition by alloantibodies, a discrete region of class I antigens may be crucial for CTL recognition.
Generation of IgG aggregates by the myeloperoxidase-hydrogen peroxide system.
Authors: Jasin H E
Published: December 2022

Incubation of native human 125I-IgG with polymorphonuclear neutrophil (PMN) peroxidase-containing granules or with purified myeloperoxidase (MPO) in the presence of H2O2 and a suitable hydrogen donor such as catechol generated large amounts of heavy IgG aggregates. Short-term incubation (15 to 60 min) of native 125I-IgG (400 microgram) with MPO-containing granules or with purified MPO (1.5 microgram) in the presence of H2O2 (0.036 to 0.36 mumol) and catechol (0.2 mumol) resulted in the generation of 8 to 100 microgram of heavy IgG aggregates (3 X 10(5) to 4 X 10(6) daltons). Aggregate formation was completely abolished by the omission of H2O2 or catechol, and by the addition of catalase, sodium azide, or cyanide. IgG aggregates were also generated with tyrosinase, tyrosine, and atmospheric oxygen. These results indicate that aggregation was due to MPO-H2O2-mediated oxidation of catechol to orthoquinone, which was deemed to be directly responsible for cross-linking by non-enzymic biochemical reactions. The IgG aggregates generated were shown to behave as typical immune complexes in that they consumed C, were detected by the solid-phase C1q and Raji cell assays, and were precipitable by monoclonal rheumatoid factor. This nonspecific oxidative protein-aggregation reaction may play an important role in the pathogenesis of tissue injury in acute and chronic inflammatory processes and in drug reactions. It could also provide an explanation for the frequent detection of circulating immune complex-like material in a large variety of acute and chronic inflammatory states.
Evidence for a lymphokine enhancing arginase activity during allograft rejection.
Authors: Dy M , Schneider E , Mavier P , Kamoun P , Lebel B , Hamburger J
Published: December 2022

The production of urea and ornithine is increased greatly in spleen cell cultures of an allograft recipient in the presence of donor cells (secondary MLC) in comparison to that of primary MLC (without previous allograft). This phenomenon appears after 24 hr of culture and reaches its maximum at 48 hr. The greatest increase in urea production is observed when the recipient spleen cells are collected at the time of allograft rejection. To obtain this extra production of urea, the stimulating cells in MLC should specifically be of the donor type or at least bear one homology with donor cells at the K or D locus. The increased production of urea and ornithine during MLC results from the action of a lymphokine released by recipient cells in the presence of donor cells. This factor acts upon cells present in bone marrow, spleen, and elicited peritoneal cells but is absent or is present in smaller quantities in thymus and lymph node cells. Target cells of this factor possess numerous macrophage features and could be immature cells of the macrophage line. The lymphokine responsible for this phenomenon is heat-stable, destroyed by trypsin, chymotrypsin, and neuraminidase, and has a m.w. around 32,000. It acts upon its target cells by increasing arginase activity, which results in the production of a large amount of ornithine, an important precursor of polyamine biosynthesis.
Induction of an activated b lymphocyte-associated surface moiety defined by the B2 monoclonal antibody by ebv conversion of an EBV-negative lymphoma line (Ramos): differential effect of transforming (B95-8) and nontransforming (P3HR-1) EBV substrains.
Authors: Klein G , Ehlin-Henriksson B , Schlossman S F
Published: December 2022

The expression of the B2 antigen, defined by a monoclonal antibody, was studied on Burkitt lymphoma lines, lymphoblastoid cell lines, leukemia and myeloma lines, hybrids between different hemapoetic cell lines, and EBV-converted sublines of originally EBV-negative, B2-negative B lymphoma lines. In confirmation of earlier results, the expression of B2 was found to be restricted to a relatively narrow portion of the B cell maturation pathway. Non-B cell-derived lines were uniformly negative. Hybrids derived from the fusion of highly B2-positive and B2-negative or low B2 expressing lines of B cell origin were B2-positive. In contrast, fusion of B2-positive Burkitt lymphoma lines with the primitive human erythroleukemia line K562 resulted in the complete extinction of B2 expression. These findings are in line with the expected behavior of a B cell differentiation marker. EBV conversion of the EBV-negative, B2-negative Ramos lymphoma line by the transforming B95-8 substrain of the virus regularly induced the expression of B2, whereas conversion with the nontransforming P3HR-1 substrain had no such effect, in spite of the continued presence of EBV-DNA and EBNA in both types of EBV-converted sublines. The possibility that B2 induction may reflect the action of the transforming gene(s), present in B95-8 but deleted from the P3HR-1 virus, and the implications of this possibility for the functional mapping of the EBV genome are discussed.
Enrichment of epidermal Langerhans cells by immunoadsorption to Staphylococcus aureus cells.
Authors: Schuler G , Auböck J , Linert J
Published: December 2022

In addition to keratinocytes and melanocytes, the mammalian epidermis harbors the so-called Langerhans cells (LC)2 as a third cell population, which is thought to participate in immune reactions involving the epidermis (1, 2). LC are dendritic cells located above the basal cell layer, have a characteristic ultrastructural appearance (3), and originate from a bone marrow precursor (4, 5). They lack membrane-incorporated surface immunoglobulin and sheep red blood cell receptors, but are the only epidermal cells (EC) that bear receptors for the Fc portion of IgG (Fc-IgG) and for C3 and express Ia antigens (1, 2). Because LC constitute only 3 to 5% of all EC, enrichment procedures are important for functional studies. Moderate enrichment of LC to 18 to 35% by separation of Fc-IgG rosetting EC on density gradients was sufficient to show the critical role of LC in EC-induced T cell proliferation (6). More powerful isolation procedures are needed, however, for more exacting analysis of LC functions, such as their role in immune induction, their secretory capacities including production of EC-derived thymocyte-activating factor (7, 8) and prostaglandins, immune endocytosis, the role of LC granules, etc. Methods hitherto available for enriching LC beyond 60% (9, 10) are time consuming and of low yield and viability, and thus are of limited practical value. In this report we describe a simple and efficient procedure to obtain viable LC suspensions of high purity based on the use of monolayers of protein A-bearing Staphylococcus aureus cells as a solid-phase immunoadsorbent (11).
Development and function of cytotoxic T lymphocytes (CTL). I. In vivo maturation of CTL precursors in the absence of detectable proliferation results as a normal consequence of alloimmunization.
Authors: Kimura A K , Wigzell H
Published: December 2022

In the experiments reported here, we examine the need for cell division as a critical component in the clonal expansion of alloreactive CTL precursors. Unlike previous attempts to inhibit DNA synthesis and cell division non-specifically, we have chosen to follow the normal unimpeded development of CTL in two of the most commonly used in vivo and in vitro allograft systems. The development and relative contribution of CTL lymphoblast-associated cytotoxicity has been followed by density gradient separation and functional analysis of the various fractions of lymphocytes obtained throughout the entire course of sensitization. In addition to the physical parameters (size and density), even more convincing data have been obtained from in vivo administration of 3H-TdR during the entire allograft reaction. The results presented here clearly confirm CTL precursor proliferation in vitro but provide strong evidence that in vivo CTL normally arise via a mechanism independent of blast formation and cellular proliferation. Interpretations of these findings in relationship to the concept of "clonal expansion" for the generation of mature CTL are discussed.
Effects of C-reactive protein on human lymphocyte responsiveness.
Authors: Vetter M L , Gewurz H , Hansen B , James K , Baum L L
Published: December 2022

C-reactive protein (CRP), a trace serum protein that increases markedly in concentration during inflammatory reactions, was recently shown to bind to a subset of human IgG-FcR-bearing peripheral blood lymphocytes in the presence of a ligand such as pneumococcal C-polysaccharide (CPS). CRP has also been detected on a small percentage of PBL that are associated with NK activity. In the present study, we assessed the effects of CRP and CRP-CPS complexes on a variety of human lymphocyte functions in vitro. CRP and CRP complexes significantly enhanced (generally two to threefold) cell-mediated cytotoxicity, minimally enhanced the MLC reaction, and induced a small but regularly detectable blastogenic response in resting PBL. CRP or CRP-CPS complexes had no effect on mitogen-induced blastogenesis, PWM-induced generation of IgM plaque-forming cells, E-rosette formation, antibody-dependent cell-mediated cytotoxicity, or NK activity. The basis for the preferential ability of CRP to enhance cytotoxicity responses in vitro is under further investigation.
Analytical and functional studies on the T cells of untreated and immunologically tolerant diabetes-prone BB rats.
Authors: Naji A , Silvers W K , Kimura H , Bellgrau D , Markmann J F , Barker C F
Published: December 2022

Lymphocyte profiles of untreated diabetes-prone BB rats (BBDP) and their normal marrow-inoculated tolerant littermates were determined with the aid of a fluorescence-activated cell sorter by using monoclonal antibodies specific for rat T cell (W3/13) and T cell subsets (W3/25, T helper; OX8, T cytotoxic/suppressor). In contrast to non-diabetes-prone rats and to their marrow-inoculated littermates, untreated BBDP rats were found to be T lymphocytopenic with reduced W3/25+ cells and with a major loss of OX8+ cells. Moreover, their lymphocytes displayed depressed alloreactivity that was not restored by addition of exogenous IL 2.
IA mutant functional antigen-presenting cell lines.
Authors: Glimcher L H , Hamano T , Asofsky R , Sachs D H , Pierres M , Samelson L E , Sharrow S O , Paul W E
Published: December 2022

We describe a protocol for the selection of mutant cells with an altered pattern of Ia antigenic determinants and antigen-presenting properties from a homogeneous population of functional antigen-presenting cells (APC). The APC line used in this work was obtained by fusing lipopolysaccharide-stimulated B cells from (BALB/c x A/J)F1 donors with cells from the M12.4.1 BALB/c B lymphoma cell line. The resulting hybridomas, including TA3, retained the potent antigen-presenting activity of the parental B lymphoma line and expressed Ia antigens and immune response gene-determined antigen-presenting properties of the A/J type. Mutants of TA3 were obtained by subjecting the cells to negative immunoselection with one monoclonal anti-(alpha) 1-Ak antibody and complement followed by positive immunoselection via electronic cell sorting with a second monoclonal alpha I-Ak or alpha I-Ek antibody. Two types of mutants were obtained. One, A8, appeared to have undergone a fairly limited alteration, since it lost only some of the I-Ak antigenic determinants; the second type appeared to have lost the entire I-Ak molecule but to have retained the I-E molecule. Functional studies with the A8 mutant demonstrated that the loss of a limited number of I-Ak determinants correlated with the loss of a specific I-Ak-encoded restriction element, since A8 failed to present a specific antigen, hen egg lysozyme (HEL), to a HEL-specific I-Ak-restricted T cell hybridoma but retained some capacity to present a second antigen, poly(Glu60Ala30Tyr10) (GAT), to a GAT-specific I-Ak-restricted T cell hybridoma. These results indicate that Ia antigens are the products of immune response gene loci. The availability of such mutants should allow an examination of the relationship between the structure of an Ia molecule and the antigens with which it is co-recognized by T cells.
The recognition specificity of a murine helper T cell for hemagglutinin of influenza virus A/PR/8/34.
Authors: Gerhard W , Hackett C , Melchers F
Published: December 2022

A T cell line was established in long-term tissue culture from spleen cells of BALB/c mice immunized with influenza virus PR8 (A/PR/8/34(H1N1)) by continuous restimulation with PR8 virus and syngeneic x-irradiated spleen cells. This T cell line and clones derived from it have now been propagated for over 1 yr "in vitro". The T cell line and the clones, upon stimulation with Con A in the absence of antigen and irradiated spleen cells, as upon stimulation in the presence of antigen and adherent cells, produce T cell growth factors, B cell replication and maturation factors, and colony-stimulating factors, as tested by restimulation of proliferation of a clone of cytolytic murine T cells, of lipopolysaccharide-activated B cell blasts, and by macrophage/granulocyte colony formation of murine bone marrow cells, respectively. The T cell line and the clones help syngeneic B cells in the presence of syngeneic irradiated spleen cells and PR8 virus to proliferate and mature into clones of cells secreting virus-specific antibodies. In the presence of PR8 virus and of a bystander antigen, such as sheep red cells, B cells specific for this bystander antigen are also induced. Adoptive transfer of the T cells i.v. into syngeneic nu/nu BALB/c mice enable the recipient mice to produce, upon challenge with PR8, virus-specific antibodies and to clear virus infection of the lung. The virus-specific T cell line and the clones are restricted by H-2 antigens of the d-haplotype, probably by Iad, and recognize a determinant on the hemagglutinin (HA) molecule of PR8 virus. Fifty to 100 fmol of virus-associated or free HA suffice for stimulation as measured by proliferation assays. The stimulating determinant is present on the HA of all natural virus isolates of the H1 subtype, is absent from virus isolates of the H2 and H3 subtypes, and is abolished if glutamic acid at position 115 of the HA1 polypeptide of PR8 is replaced by lysine.