bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased class I and class II MHC products and mRNA in kidneys of MRL-lpr/lpr mice during autoimmune nephritis and inhibition by cyclosporine.
Authors: Halloran P F , Urmson J , Ramassar V , Laskin C , Autenried P
Published: December 2022

The expression of MHC products in the kidneys of MRL-1pr/1pr mice was investigated. As previously described, these mice develop lupus-like nephritis with intraglomerular and peritubular Ig deposition, vasculitis, and interstitial mononuclear cell infiltration at about 12 wk of age. As the nephritis appeared, the expression of MHC class I and II products rose, as demonstrated by absorption and by specific binding of radiolabeled antibodies. Hybridization of kidney RNA with specific probes revealed an increase in specific mRNA for MHC class I and II genes and for beta2 microglobulin. Using rat monoclonals against mouse class I and II MHC products, and goat anti-rat Ig as second antibody, we showed that the increase in renal class I and II expression was localized to the basolateral membranes of tubular cells, and, in the case of class I, in arteries and glomeruli. The sites of tubular MHC expression corresponded closely to the sites of extensive peritubular Ig deposition. High doses of cyclosporine given for 6 to 8 wk reduced the peritubular Ig deposits, renal Ia and H-2K expression, and specific mRNA for beta 2-microglobulin and MHC genes, but did not reduce anti-DNA antibody levels in serum. Thus the peritubular Ig deposits and tubular MHC induction coincided in timing and location, and in their resolution with cyclosporine. The results raise the possibility that the increase in renal MHC expression not only accompanies the renal lesions, but may play a role in their pathogenesis.
Distribution of the murine plasma cell antigen PC-1 in non-lymphoid tissues.
Authors: Harahap A R , Goding J W
Published: December 2022

PC-1 is an alloantigen of murine plasma cells. Its close association with secretory function in lymphoid cells previously raised the question of whether PC-1 was part of the secretory apparatus. In addition to its expression on lymphocytes, PC-1 had been known to be present in liver, brain, and kidney, although the data were derived almost entirely from bulk absorption studies of polyclonal alloantisera, and virtually nothing was known about the nature of the cells expressing PC-1 in these organs. If PC-1 was functionally involved in the secretory process. it might be expected to be present at secretory sites within these and other organs. We now report the results of an immunohistochemical survey of the distribution of PC-1 in a variety of non-lymphoid organs, using a mAb. The PC-1 Ag was found in a small number of highly discrete locations that were mostly, but not exclusively, associated with epithelia. Sites of strong expression included the distal convoluted tubule of the kidney, ducts of the salivary glands, epididymis, proximal part of the vas deferens, and chondrocytes. The PC-1 glycoprotein was also found in the capillaries of the brain, but did not appear to be present in capillaries elsewhere, a pattern that is strikingly similar to that of the receptor for the iron transport protein, transferrin. Negative sites included the thyroid, pancreas, choroid plexus, smooth and striated muscle, stomach, small and large intestine, gall bladder, renal glomeruli, testis, and seminal vesicles. These results are not consistent with a generalized role for PC-1 in secretion, but are compatible with a role in a specialized subset of macromolecular transport events.
IL-4 is required to generate and sustain in vivo IgE responses.
Authors: Finkelman F D , Katona I M , Urban J F , Holmes J , Ohara J , Tung A S , Sample J V , Paul W E
Published: December 2022

Antibodies of the IgE isotype play a predominant role in immediate hypersensitivity reactions. IL-4, a T cell-derived lymphokine that stimulates increased Ia expression by resting B cells and increased IgG1 secretion by LPS-activated B cells in vitro, has also been shown to regulate in vitro and in vivo polyclonal IgE responses. We report that large quantities of a purified anti-IL-4 mAb inhibit primary in vivo polyclonal IgE responses by 99% in mice infected with Nippostrongylus brasiliensis or injected with anti-IgD antibodies, and totally inhibit secondary Ag-specific IgE responses to TNP-keyhole limpet hemocyanin without effect on either IgG1 or IgG2a responses to these stimuli. The lack of effect of anti-IL-4 antibody on IgG1 secretion cannot be explained simply by inadequate neutralization of IL-4, inasmuch as the doses of anti-IL-4 antibody used blocked an N. brasiliensis-induced increase in B cell Ia expression by more than 85%, whereas in vitro studies indicate that enhancement of B cell Ia expression requires less IL-4 than induction of IgG1 secretion. In addition to demonstrating that IL-4 plays a necessary role in the generation of an in vivo IgE response, we show that IL-4 has an important role in sustaining established IgE responses, because anti-IL-4 antibody, when given at the peak of an N. brasiliensis- or TNP-keyhole limpet hemocyanin-induced IgE response, accelerates the declines in total serum IgE and in IgE anti-TNP antibody levels, respectively. These observations suggest that the effects of IL-4 on in vivo immune responses may be more specific than might have been predicted from in vitro observations, and that regulation of IL-4 production or action may be useful for the prevention or therapy of immediate hypersensitivity disorders.
Temporal adaptation of neutrophil oxidative responsiveness to n-formyl-methionyl-leucyl-phenylalanine. Acceleration by granulocyte-macrophage colony stimulating factor.
Authors: English D , Broxmeyer H E , Gabig T G , Akard L P , Williams D E , Hoffman R
Published: December 2022

This investigation was undertaken to clarify the mechanism by which purified recombinant human granulocyte-macrophage colony stimulating factor (GM-CSF) potentiates neutrophil oxidative responses triggered by the chemotactic peptide, FMLP. Previous studies have shown that GM-CSF priming of neutrophil responses to FMLP is induced relatively slowly, requiring 90 to 120 min of incubation in vitro, is not associated with increased levels of cytoplasmic free Ca2+, but is associated with up-regulation of cell-surface FMLP receptors. We have confirmed these findings and further characterized the process of GM-CSF priming. We found that the effect of GM-CSF on neutrophil oxidative responsiveness was induced in a temperature-dependent manner and was not reversed when the cells were washed extensively to remove the growth factor before stimulation with FMLP. Extracellular Ca2+ was not required for functional enhancement by GM-CSF and GM-CSF alone effected no detectable alteration in the 32P-labeled phospholipid content of neutrophils during incubation in vitro. Our data indicate that GM-CSF exerts its influence on neutrophils by accelerating a process that occurs spontaneously and results in up-regulation of both cell-surface FMLP receptors and oxidative responsiveness to FMLP. Thus, the results demonstrate that, with respect to oxidative activation, circulating endstage polymorphonuclear leukocytes are nonresponsive or hyporesponsive to FMLP; functional responsiveness increases dramatically as surface FMLP receptors are gradually deployed after the cells leave the circulation. Thus, as neutrophils mature, their responsiveness to FMLP changes in a manner which may be crucial for efficient host defense. At 37 degrees C, this process is markedly potentiated by GM-CSF. We conclude that endogenous GM-CSF, released systemically or at sites of infection and inflammation, potentially plays an important role in host defense by accelerating functional maturation of responding polymorphonuclear leukocytes.
Release of reactive nitrogen intermediates and reactive oxygen intermediates from mouse peritoneal macrophages. Comparison of activating cytokines and evidence for independent production.
Authors: Ding A H , Nathan C F , Stuehr D J
Published: December 2022

The capacity of 12 cytokines to induce NO2- or H2O2 release from murine peritoneal macrophages was tested by using resident macrophages, or macrophages elicited with periodate, casein, or thioglycollate broth. Elevated H2O2 release in response to PMA was observed in resident macrophages after a 48-h incubation with IFN-gamma, TNF-alpha, TNF-beta, or CSF-GM. Of these, only IFN-gamma induced substantial NO2- secretion during the culture period. The cytokines inactive in both assays under the conditions tested were IL-1 beta, IL-2, IL-3, IL-4, IFN-alpha, IFN-beta, CSF-M, and transforming growth factor-beta 1. Incubation of macrophages with IFN-gamma for 48 h in the presence of LPS inhibited H2O2 production but augmented NO2- release, whereas incubation in the presence of the arginine analog NG-monomethylarginine inhibited NO2- release but not H2O2 production. Although neither TNF-alpha nor TNF-beta induced NO2- synthesis on its own, addition of either cytokine together with IFN-gamma increased macrophage NO2- production up to six-fold over that in macrophages treated with IFN-gamma alone. Moreover, IFN-alpha or IFN-beta in combination with LPS could also induce NO2- production in macrophages, as was previously reported for IFN-gamma plus LPS. These data suggest that: 1) tested as a sole agent, IFN-gamma was the only one of the 12 cytokines capable of inducing both NO2- and H2O2 release; 2) the pathways leading to secretion of H2O2 and NO2- are independent; 3) either IFN-gamma and TNF-alpha/beta or IFN-alpha/beta/gamma and LPS can interact synergistically to induce NO2- release.
High yield enzymatic conversion of intravascular leukotriene A4 in blood-free perfused lungs.
Authors: Grimminger F , Becker G , Seeger W
Published: December 2022

Experiments to investigate the fate of intravascularly administered leukotriene (LT) A4, an unstable intermediate of LT generation, were performed in isolated, ventilated, and blood-free perfused rabbit lungs. LT extracted from the lung effluent were separated by different reverse phase and straight phase HPLC procedures as methylated and nonmethylated compounds. Identity of eluting LT was confirmed by UV spectrum analysis and immunoreactivity. Pulmonary artery injection of 75 to 300 nmol of LTA4 resulted in the rapid appearance of cysteinyl-LT as well as LTB4 in the recirculating perfusate. The yield of these enzymatically generated LTA4 metabolites vs non-enzymatic hydrolysis products (6-trans-LTB4, 5-trans-epi-LTB4, 5,6-dihydroxyeicosatetraenoic acids) ranged above 90%. Experiments with application of tritiated LTA4 showed exclusive origin of the detected LT from the exogenously applied precursor. The time course of cysteinyl-LT appearance in the perfusate suggested metabolism of LTC4 via LTD4 to LTE4, whereas there was no evidence for LTB4 omega-oxidation. In the dose range of LTA4 used, the enzymatic conversion of this LT precursor did not approach saturation. Collectively, these data indicate that the intact pulmonary vasculature contains a hitherto not described capacity for enzymatic conversion of intravascularly offered LTA4 to both cysteinyl-LT and LTB4. This may be of biological significance for a putative transcellular biosynthesis of LT in the pulmonary microcirculation upon contact with LTA4 feeder cells, such as activated granulocytes.
Early influx of Listeria-reactive T lymphocytes in liver of mice genetically resistant to listeriosis.
Authors: Goossens P L , Marchal G , Milon G
Published: December 2022

Murine listeriosis is a classical model for investigating mechanisms of cellular immunity, which involves interaction of macrophages and T lymphocytes. The early course of this experimental infection is under control of a limited number of genes in the murine host. In the present study, we asked whether the early efficient control of bacterial growth in the liver of resistant mice is related to the expression of a more rapid specific immune response in this organ than in susceptible mice. Therefore, we compared the frequencies of Listeria monocytogenes-reactive T cells in blood, spleen, and liver of resistant C57BL/6 and susceptible C3H/He Past mice after i.v. injection of a high dose of Listeria (9 x 10(5) CFU). T cells were titrated through their ability to locally transfer a delayed-type hypersensitivity reaction to viable L. monocytogenes, an effector function potentially relevant to the early step of protective mechanisms. We observed (1) a 9- and 4-fold increase by day 1 in the frequency of Listeria-reactive transfer units in the blood of C57BL/6 and C3H mice, respectively, (2) no increase in the number of Listeria-reactive transfer units in the spleen of 2-day infected mice of both strains, and (3) a 90-fold increase, at day 2, in the number of Listeria-reactive transfer units in the liver of resistant C57BL/6 compared with only a 9-fold increase in the liver of susceptible C3H/He. These results suggest that the ability of C57BL/6 mice to control the early bacterial growth (0 to 48 h) in their liver, may be related to a rapid influx of L. monocytogenes-reactive T lymphocytes.
Differential recognition of Leishmania aethiopica antigens by lymphocytes from patients with local and diffuse cutaneous leishmaniasis. Evidence for antigen-induced immune suppression.
Authors: Akuffo H O , Fehniger T E , Britton S
Published: December 2022

Data are presented to suggest that differential Ag expression by parasites derived from diffuse (DCL) vs local (LCL) cutaneous leishmaniasis patients may be responsible for the Ag-specific anergy seen in DCL patients. The evidence suggests that promastigotes derived from DCL patients express epitopes which preferentially stimulate suppressor activities in DCL patients. These determinants appear to be expressed less, if at all by promastigotes derived from LCL patients. The Ag-specific suppression or nonresponsiveness which dominates the immune response in DCL patients during an active infection can be abrogated by drug treatment or removal of live DCL parasites, which suggests that Ag-induced regulatory cells, probably of T cell lineage, are most likely responsible for the nonresponsiveness seen in untreated DCL patients. Thus the mechanisms of immune regulation operating in this disease differ from that of lepromatous leprosy where the specific unresponsiveness (anergy) is irreversible even after successful treatment.
A study of functionally active amino acids involved in the interaction of HLA-A2 or HLA-A3 molecules with cytolytic T lymphocytes.
Authors: Healy F , Sire J , Gomard E , Yssel H , Jordan B , Levy J P
Published: December 2022

A large series of HLA-A2/HLA-A3 recombinant genes were generated by using the in vivo recombination technique. These genes have each been modified in the last two-thirds of the third exon such that one or several HLA-A2-specific substitutions have been made in the HLA-A3 gene and vice versa. The recombinant genes were transfected into the murine cell line P815 and the transfectants were used as targets for a series of 20 human CTL lines or clones specific for HLA-A2 or HLA-A3, or restricted by HLA-A2 and specific for influenza A. Several patterns of anti-HLA-A2, anti-HLA-A3, and HLA-A2-restricted anti-influenza CTL activity were observed and when uncloned cell lines were studied, a progressive selection of some clones with a similar pattern of activity was regularly found. From the comparison of these different patterns the following conclusions can be drawn: 1) In most but not all cases both domains of the class I molecule were essential for CTL recognition, but residue 152 was critically important for the majority of CTL tested; 2) amino acids 114/116 were also critical in most cases, and their position close to amino acid 152 in the tertiary structure of the molecule may have some functional significance; and 3) amino acid 161, although highly conserved, plays an unexpected but very important role in CTL function.
Identification by site-directed mutagenesis of amino acid residues contributing to serologic and CTL-defined epitope differences between HLA-A2.1 and HLA-A2.3.
Authors: Hogan K T , Clayberger C , Bernhard E J , Walk S F , Ridge J P , Parham P , Krensky A M , Engelhard V H
Published: December 2022

Site-directed mutagenesis of HLA-A2.1 has been used to identify the amino acid substitutions in HLA-A2.3 that are responsible for the lack of recognition of the latter molecule by the HLA-A2/A28 specific antibody, CR11-351, and by HLA-A2.1 specific CTL. Three genes were constructed that encoded HLA-A2 derivatives containing one of the amino acids known to occur in HLA-A2.3: Thr for Ala149, Glu for Val152, and Trp for Leu156. Three additional genes were constructed that encoded the different possible combinations of two amino acid substitutions at these residues. Finally, a gene encoding all three substitutions and equivalent to HLA-A2.3 was constructed. These genes were transfected into the class I negative, human cell line Hmy2.C1R. Analysis of this panel of cells revealed that recognition by the antibody CR11-351 was completely lost when Thr was substituted for Ala149, whereas substitutions at amino acids 152 and 156, either singly or in combination, had no effect on the binding of this antibody. The epitopes recognized by the allogeneic and xenogeneic HLA-A2.1 specific CTL clones used in this study were all affected by either one or two amino acid substitutions. Of those epitopes sensitive to single amino acid changes, none were affected by the substitution of Thr for Ala149, whereas all of them were affected by at least one of the substitutions of Glu for Val 152 or Trp for Leu156. Overall, amino acid residue 152 exerted a stronger effect on the epitopes recognized by HLA-A2.1 specific CTL than did residue 156. Of those epitopes affected only by multiple amino acid substitutions, double substitutions at residues 149 and 152 or at 152 and 156 resulted in a loss of recognition, whereas a mutant with substitutions at residues 149 and 156 was recognized normally. This reemphasizes the importance of residue 152 and indicates that residue 149 can affect epitope formation in conjunction with another amino acid substitution. These results are discussed in the context of current models for the recognition of alloantigens and in light of the recently published three-dimensional structure of the HLA-A2.1 molecule.
Constitutive expression of a phosphorylated activation antigen (Leu 23) by CD3bright human thymocytes.
Authors: Testi R , Phillips J H , Lanier L L
Published: December 2022

Leu 23 is a human cell surface differentiation Ag expressed very early during lymphoid cell activation. Resting T lymphocytes do not express Leu 23. However, expression of Leu 23 glycoprotein can be induced on the Jurkat T leukemia cell line within a few hours after stimulation with soluble anti-CD3 mAb or Con A. After removal of the stimulus Leu 23 is expressed for greater than 30 h. A total of 20 to 30% of resting human thymocytes was unexpectedly stained by anti-Leu 23 mAb. Biochemical analysis revealed that the Leu 23 Ag expressed on thymocytes is a phosphorylated disulfide-linked dimer composed of 28- and 32-kDa subunits. Within the thymus, Leu 23 is preferentially expressed on the CD3bright, mostly CD4+ CD8- or CD4- CD8+ subpopulations. By contrast, CD3dim CD4+CD8+ thymocytes expressed only very low levels of Leu 23, and CD7+ CD3- CD4- CD8- thymocytes were Leu 23-. However, Leu 23 was induced on the CD3dim thymocytes by in vitro culture of thymocytes with anti-CD3-conjugated Sepharose. The transition from CD3dim to CD3bright within the thymus may be an important differentiation stage and influence selection of the antigenic repertoire. Therefore, the ability to detect subpopulations within the thymus that express Leu 23 Ag may help to identify thymocytes activated in vivo, possibly by the functional engagement of their CD3/TCR.
Inverse relationship between proliferation and differentiation in a human TNP-specific B cell line. Cell cycle dependence of antibody secretion.
Authors: Golding B , Pillemer S R , Roussou P , Peters E A , Tsokos G C , Ballow J E , Hoffman T
Published: December 2022

Studies of an EBV-transformed and TNP-specific human B cell line revealed that, unlike myeloma or hybridoma cell lines that consist mainly of fully differentiated cells, most of the cloned EBV-transformed cells were not fully differentiated, as judged by inability to bind TNP-SRBC and to secrete anti-TNP antibody. The minority of more differentiated cells were selected by TNP-SRBC rosetting. They were found to proliferate to a lesser extent than nonrosetting cells and to contain increased numbers of antibody-secreting cells. This inverse relationship between proliferation and differentiation was also shown to be cell cycle related in that the TNP-SRBC rosetting cells resided, to a greater extent than the nonrosetting cells, in the G1 phase of the cell cycle. The finding that the G1 phase of the cell cycle was associated with differentiation into anti-TNP secreting cells was confirmed by demonstrating that treatment with hydroxyurea, which arrests the cells in G1, resulted in decreased proliferation and an increased proportion of antibody-secreting cells. Similarly, addition of phorbol ester resulted in increased antibody secretion and decreased proliferation, suggesting a role for protein kinase C in this differentiation pathway. The strategy of increasing the number of antibody-producing cells in this human EBV line, by promoting differentiation of the cells in G1, may be relevant to the large scale production of specific human mAb for the treatment and diagnosis of human diseases.
Individual class II-restricted antigenic determinants of the same protein exhibit distinct kinetics of appearance and persistence on antigen-presenting cells.
Authors: Eisenlohr L C , Gerhard W , Hackett C J
Published: December 2022

The kinetics of presentation of class II-restricted T cell determinants of influenza virus hemagglutinin (HA) was investigated over a 48-h time course after pulsing of A20 B lymphoma APC with non-replicative virus or isolated HA. At intervals after Ag pulse, APC were fixed with paraformaldehyde to arrest Ag processing and to preserve the expression levels of the presented determinants. Expression of T cell sites at each time point was probed by a panel of BALC/c T hybridomas specific for the HA of influenza A/Puerto Rico/8/34 virus, recognizing either site 1 (residues 111 to 119), site 2 (126 to 138), or site 3 (302 to 313). Characteristic patterns of presentation were observed for each site: sites 2 and 3 achieved maximal expression by 8 h post pulse, but declined thereafter, whereas site 1 presentation continued to increase over time. The quantitative expression of each T cell site was affected by the proteolysis inhibitor leupeptin, resulting in partial inhibition of site 1, complete blocking of site 2, but enhancement of site 3. However, the expression kinetics of sites 1 and 3, which could be observed in the presence of the inhibitor, remained qualitatively unchanged. These observations indicate that some T cell determinants (e.g., HA site 1) may exhibit a greater longevity of expression on APC than other antigenic sites of the same protein. Differences in the persistence of surface expression of distinct T cell sites may be a factor in their relative immunodominance.
Soluble IL-2 receptor in rheumatoid arthritis. Correlation with disease activity, IL-1 and IL-2 inhibition.
Authors: Symons J A , Wood N C , Di Giovine F S , Duff G W
Published: December 2022

An ELISA was used to measure soluble IL-2R (sIL-2R) in the sera and synovial fluids of patients with rheumatic diseases. Patients with rheumatoid arthritis had raised levels of sIL-2R both in their sera and in their synovial fluid compared to patients with osteoarthritis and age-matched healthy controls. Mononuclear cells from the synovial fluid of rheumatoid arthritis patients were found to produce spontaneously high levels of sIL-2R which eluted at approximately m.w. 40,000 on gel filtration. In contrast, autologous peripheral blood cells only produced comparable levels upon stimulation with mitogenic lectin. Sequential studies indicated that serum sIL-2R levels were highly correlated with disease activity, indicating that measurement of sIL-2R may be a useful clinical marker in the future. Within the joint, synovial fluid sIL-2R levels correlated significantly with immunoreactive IL-1 beta levels, providing evidence for a role of IL-1 in immune activation in the synovium. In synovial fluids, sIL-2R level also correlated with functional inhibition of IL-2-driven responses in vitro. Furthermore, sIL-2R immunoreactivity in synovial fluid eluted at m.w. 100,000 coeluting with IL-2-inhibitory activity and consistent with a role for sIL-2R in down-regulation of IL-2 responses. The abnormal m.w. may be accounted for by complex formation in the synovial fluid. Given the ability of sIL-2R to bind IL-2, the presence of sIL-2R within the joint may contribute to the well documented "IL-2 defect" seen in rheumatoid arthritis.
Anti-proliferative effect of IFN-gamma in immune regulation. II. IFN-gamma inhibits the proliferation of murine bone marrow cells stimulated with IL-3, IL-4, or granulocyte-macrophage colony-stimulating factor.
Authors: Gajewski T F , Goldwasser E , Fitch F W
Published: December 2022

A biphasic dose response curve was observed when the bone marrow-derived cell line FDCP1, used as an indicator line for IL-3 bioassays, was exposed to supernatants from some activated T cell clones but not others. The active component which inhibited proliferation at the higher supernatant concentrations appeared to be IFN-gamma, based on the following observations. 1) Only those culture supernatants which contained IFN-gamma gave a biphasic dose response curve; 2) with these supernatants, an anti-IFN-gamma mAb augmented the proliferation of FDCP1 cells at the higher supernatant concentrations; and 3) rIFN-gamma profoundly inhibited the proliferation of FDCP1 cells stimulated with rIL-3 or rIL-4. rTNF-alpha inhibited FDCP1 proliferation only to a modest extent, yet the combination of rTNF-alpha + rIFN-gamma provided greater inhibition than each agent alone. The proliferation of a second bone marrow-derived cell line, DA1, was not inhibited by rIFN-gamma or rIFN-gamma + rTNF-alpha when stimulated with rIL-3 or recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF). Fresh bone marrow cells also showed a suboptimal proliferative response when stimulated with T cell supernatants containing IFN-gamma, and this response was augmented considerably upon the addition of anti-IFN-gamma mAb. Bone marrow cell proliferation was observed upon exposure to rIL-3, rIL-4, or rGM-CSF, and these responses were inhibited by rIFN-gamma; rTNF-alpha also produced a synergistic effect with these cells. Bone marrow cell colony formation stimulated by rIL-3 or rGM-CSF also was inhibited by rIFN-gamma. Colony formation in bone marrow cell cultures was not observed in response to rIL-4. Collectively, these results suggest that Th1 cells, which in addition to IL-3 and GM-CSF also produce IFN-gamma, may regulate hemopoietic cell proliferation and colony formation differently from the way Th2 cells do, which do not produce IFN-gamma.
Characterization of the murine T cell receptor for IgE (Fc epsilon RII). Demonstration of shared and unshared epitopes with the B cell Fc epsilon RII.
Authors: Mathur A , Conrad D H , Lynch R G
Published: December 2022

Antigenic relationships between the low affinity Fc epsilon R present on murine B and T lymphocytes were studied. A rat mAb (B3B4) and two polyclonal antisera produced by immunizing with the murine B lymphocyte Fc epsilon RII were examined for their ability to inhibit binding of IgE to murine B or T lymphocytes, using an IgE-specific rosette assay. One polyclonal antiserum (goat-anti-mouse Fc epsilon R) inhibited binding of IgE to both B and T lymphocytes, whereas another polyclonal antiserum (rabbit-anti-mouse Fc epsilon R) and the rat mAb inhibited the binding of IgE to B lymphocytes but did not influence the binding of IgE to T lymphocytes. When lymphocytes were surface labeled with 125I, 49-kDa and 38-kDa IgE-binding proteins were immunoprecipitated from B lymphocyte lysates by B3B4 and from B and T lymphocyte lysates by the goat antiserum. Taken together, these results suggest that the Fc epsilon R present on murine B and T lymphocytes are structurally related receptors that share some, but not all, epitopes.
Structural polymorphism of the human platelet Fc gamma receptor.
Authors: Looney R J , Anderson C L , Ryan D H , Rosenfeld S I
Published: December 2022

A variable T lymphocyte proliferative response to murine IgG1 anti-T3 monoclonal antibodies, in which most North American Caucasians respond whereas a minority do not, is well established. This is most likely the result of a genetic polymorphism manifested by 1) the inability of the monocyte 40-kDa IgG FcR of some individuals to bind murine IgG1, and 2) a distinctive trimorphic pattern on IEF of the monocyte 40-kDa FcR, one form being seen in all individuals who do not respond and another form (or a combination of both forms) being seen in those who do respond. We have evaluated the IEF patterns of the platelet 40-kDa FcR and find that in every individual tested the pattern for platelet FcR correlates with that seen for the monocyte 40-kDa FcR pattern. Furthermore, the platelets of those individuals whose "nonresponder" monocyte 40-kDa FcR did not mediate a murine IgG1 anti-T3 response did not respond with an aggregation reaction to murine IgG1 immune complexes (opsonized E). In contrast, platelets from donors possessing "responder" monocytes displayed positive "aggregation" responses to E coated with murine IgG1 antibody. However, the platelet FcR structural polymorphism described earlier did not correlate with the donor-specific variability in capacity of platelets to respond functionally to aggregated human IgG described in an earlier paper. Rather, the variation in capacity of platelets from individual donors to respond functionally to aggregated human IgG was related to the quantitative expression of platelet FcR. These data indicate that the molecular mechanisms responsible for the platelet 40-kDa FcR structural polymorphism are quite different from the mechanisms governing the variation in quantitative expression of the receptor.
Substance P augmentation of CSF-1-stimulated in vitro myelopoiesis. A two-signal progenitor restricted, tuftsin-like effect.
Authors: Moore R N , Osmand A P , Dunn J A , Joshi J G , Rouse B T
Published: December 2022

The inflammatory neuropeptide substance P acted as a costimulant for macrophage CSF-1-induced clonal proliferation of murine marrow-derived two signal-dependent mononuclear phagocyte progenitors. Substance P had no effect on clonal proliferation by progenitors responding solely to CSF-1. Substance P fragment 2-11 had no costimulatory activity; however, SP fragment 1-4 retained the full activity of the parent undecapeptide. Fragment 1-4 (ARG-PRO-LYS-PRO), a peptide containing a PRO residue between two positive charges, is a tuftsin-like (THR-LYS-PRO-ARG) tetrapeptide, and tuftsin exerted an identical costimulatory effect. Substance P, SP:1-4, and tuftsin were optimally effective as costimulants at 10(-7) to 10(-6) M. (ALA1)-tuftsin, an inhibitory analog of tuftsin, was a potent negative regulator of two signal-dependent colony formation. (ALA1)-tuftsin at concentrations less than or equal to 10(-9) M exerted dose-dependent inhibition of the positive effects of optimal concentrations of all of the co-stimulants tested, including bacterial LPS. The inhibitory tetrapeptide was equivalent in activity to ferritin, an established inhibitor of two signal-dependent colony formation. The results indicated that SP may influence myelopoiesis in addition to its other inflammatory and immunopotentiating properties. In addition, a potentially valuable modulator of SP and LPS responses in this system, (ALA1)-tuftsin, was identified.
Human monoclonal antibodies reactive with antigens of the group A Streptococcus and human heart.
Authors: Cunningham M W , McCormack J M , Talaber L R , Harley J B , Ayoub E M , Muneer R S , Chun L T , Reddy D V
Published: December 2022

Human mAb were produced from tonsillar or PBL of normal individuals or patients infected with group A streptococci. Lymphocytes were purified on Ficoll-Hypaque gradients and stimulated in vitro with purified group A streptococcal membranes or M protein extracts. The mAb were selected for study based on their reaction with group A streptococci, pep M5 protein, and/or M6 Escherichia coli protein. Further analysis by Western immunoblot or competitive inhibition ELISA revealed that there were two types of antibodies: one type that reacted with myosin and DNA and the other type that reacted with myosin, keratin, and/or actin. The specificities of these human mAb are similar to specificities observed in our previous studies of murine mAb reactive with group A streptococci and heart Ag. For comparison, anti-myosin antibodies were affinity purified from the sera of infected or acute rheumatic fever patients and were shown to react with myosin and DNA as well as with group A streptococci and M protein. To affinity purify these antibodies from normal sera, five times the amount of sera was required to obtain detectable quantities. These data suggest that the human mAb reactive with group A streptococci and myosin reflect the antibodies seen in sera from infected patients or acute rheumatics and that the B lymphocyte clones capable of producing these cross-reactive antibodies are also present in normal individuals.
Restricted Ig variable region gene expression among Ly-1+ B cell lymphomas.
Authors: Pennell C A , Arnold L W , Haughton G , Clarke S H
Published: December 2022

The majority of the characterized Ly-1+ B cell lymphomas of B10.H-2aH-4bp/Wts origin (the CH series) bear surface Ig related by Ag specificity or idiotype or both. To determine the genetic basis for these structural similarities, we have sequenced the VH and VL region genes expressed by 10 CH lymphomas, and have compared their VH and V kappa gene rearrangements by Southern blot analysis to one another and to those of four other CH lymphomas. Sequence analysis identified only five different VH, and seven different VL genes, and indicated that these V genes are essentially unmutated. CH lymphomas which express the identical VH gene share at least one idiotope. Thus, the basis for shared idiotype and specificity is due in most cases to the use of the same V gene. This restriction in V gene expression is not due to the preferential use of V genes of any particular VH family or VL group, as the expressed V genes belong to four different VH families and four V kappa groups, and include V lambda 1 and V lambda 2. We hypothesize that Ag selection accounts for the restriction in V gene usage among CH lymphomas.
IgE-binding protein. Subcellular location and gene expression in many murine tissues and cells.
Authors: Gritzmacher C A , Robertson M W , Liu F T
Published: December 2022

We show that IgE-binding protein (epsilon BP) is found primarily in the cytoplasm of rat basophilic leukemia (RBL) cells and COS-1 cells transfected with epsilon BP cDNA. Antibodies to a synthetic peptide internal to epsilon BP were generated that specifically recognized epsilon BP by protein immunoblotting. These antibodies also bind the surface of RBL cells. Surprisingly, blot hybridization analysis of RNA from nine various normal rat tissues showed that the epsilon BP gene is transcribed in all the tissues tested as well as in a mouse macrophage-like cell line.
Characterization of lymphoid tumors induced by a recombinant murine retrovirus carrying the avian v-myc oncogene. Identification of novel (B-lymphoid) tumors in the thymus.
Authors: Brightman B K , Chandy K G , Spencer R H , Gupta S , Pattengale P K , Fan H
Published: December 2022

Lymphoid tumors induced by a recombinant murine retrovirus carrying the v-myc oncogene of avian MC29 virus were characterized. The Moloney murine leukemia virus myc oncogene (M-MuLV (myc], carried by an amphotropic MuLV helper, induced tumors in NIH Swiss and NFS/N mice after a relatively long latency (8 to 24 wk). Tumor masses appeared in the thymus, spleen, and lymph nodes. Flow cytometry of the tumor cells indicated that approximately 50% were positive for Thy 1.2. Most of these tumors also expressed one or more other cell surface markers of thymocytes and mature T cells (CD4, CD8). Southern blot hybridization revealed genomic rearrangements for the TCR beta genes. The TCR beta analysis suggested that the M-MuLV(myc)-induced Thy 1.2+ tumors were derived from somewhat less mature cells than tumors induced by M-MuLV, which is a classical non-acute retrovirus lacking an oncogene. The remainder of the M-MuLV(myc)-induced tumors were Thy 1.2-, but they were positive for Ly-5 (B220) and also for MAC-2. The Thy 1.2- tumors were characteristically located in the thymus. However, they were negative for TCR beta gene rearrangements. Some, but not all, of the Thy 1.2- tumors contained rearrangements for Ig genes. Additionally, they typically expressed mRNA specific for B but not for T cells. Thus, these thymic tumors had characteristics of the B cell lineage. Tumor transplantation experiments demonstrated that the Thy 1.2- tumor cells could reestablish in the thymus and spleen of irradiated hosts, and low level expression of the Thy 1 molecule was observed in the thymus but not the spleen on the first passage. After serial passage, one Thy 1- tumor altered its cell surface phenotype to Thy 1low B220-.
Synergistic antitumor activity with IFN and monoclonal anti-idiotype for murine B cell lymphoma. Mechanism of action.
Authors: Basham T Y , Race E R , Campbell M J , Reid T R , Levy R , Merigan T C
Published: December 2022

Combination therapy with syngeneic anti-idiotype antibody and human hybrid rIFN-alpha A/D synergistically increase survival in C3H/HeN mice challenged with a lethal dose of tumor cells. C3H/HeJ mice, which have previously been described to be LPS hyporesponsive and have a defect in Fc gamma R function, did not respond to anti-idiotype therapy as well as C3H/HeN normal mice. This defect was completely corrected in animals treated simultaneously with IFN. Anti-idiotype mAb that was cleaved into F(ab')2 fragments no longer had any antitumor activity alone and could not be enhanced by IFN therapy. These results suggest that antibody is functioning through Fc gamma R-bearing effector cells that are enhanced by IFN therapy. Synergy between IFN and anti-idiotype mAb was maintained in nude mice lacking classical T cells but was reduced in C3H beige mice lacking classical NK/killer cells. IFN did not increase idiotype expression on the tumor cells but did increase H-2 expression. Although we have previously shown that rIFN-alpha A/D can directly kill 38C13 in vitro, an IFN-resistant subclone derived from 38C13, SIR-1, was equally or more responsive to human rIFN-alpha A/D in vivo and had a synergistic antitumor response to combination IFN and anti-idiotype therapy, indicating that IFN acts primarily through host mediated effects rather than direct effects.
Heterologous cross-linking of Lyt-2 (CD8) to the alpha beta-T cell receptor is more effective in T cell activation than homologous alpha beta-T cell receptor cross-linking.
Authors: Boyce N W , Jönsson J I , Emmrich F , Eichmann K
Published: December 2022

Ag recognition of Lyt-2 (CD8)-positive T lymphocytes requires the presentation by APC of a suitably processed Ag in association with MHC class I molecules. In previous studies we have obtained evidence that, for optimal activation, both the alpha beta-TCR and Lyt-2 have to participate in this recognition process. In the current study we investigate the functional consequences of limited cross-linking of these cell surface molecules by using soluble, dimeric hetero- and homoconjugates of mAb to Lyt-2 and to the TCR beta-chain (F23.1). Heterologous cross-linking of Lyt-2 to the TCR induced a vigorous, selective Lyt-2+ T cell proliferative response. Functionally active cytotoxic cells were generated, and a high frequency of responding cells was observed in limiting dilution analyses. In contrast, homologous TCR cross-linking initiated a less pronounced proliferation with a relatively low frequency of response, whereas Lyt-2 cross-linking resulted in no cellular proliferation. Significant T cell activation occurred with exposure to anti-Lyt-2: F23.1 mAb dimers at concentrations an order of magnitude lower than those required for stimulation by F23.1:F23.1 mAb dimers. The induction of proliferation by mAb dimers occurred in the absence of Fc components and in rigorously APC depleted, purified T cell preparations. Effective stimulation of resting T cells could be induced also by heterodimers of monovalent Fab fragments. Heterologous cross-linking of Lyt-2 to the TCR was superior to homologous TCR cross-linking primarily with respect to proliferation in IL-2 containing media and to IL-2R expression, whereas proliferation in response to other lymphokines and the production of IL-2 itself were similar under both cross-linking regimens. Thus, when linked to the TCR, Lyt-2 contributed a strong, positive signal toward IL-2-dependent growth of resting T cells. We assume that in the case of Ag-driven T cell activation, the class I MHC molecule acts as the physiologic cross-linking ligand for Lyt-2 and the TCR.
Alloantigen presentation by B cells. Requirement for IL-1 and IL-6.
Authors: McKenzie D
Published: December 2022

We have evaluated the requirements for non-activated allogeneic B cells to present alloantigen in primary MLC. We found that the generation of an MLR was dependent on the addition of exogenous IL-1 and IL-6 to the cultures; neither lymphokine by itself was capable of significantly stimulating the response. Our results suggest that the concentration of these lymphokines present in a standard MLR culture may serve to regulate the magnitude of the proliferative response. The B cells that co-stimulated with IL-1 and IL-6 were found to be contained almost exclusively within the large, low density population. Presumably, large low density B cells have attained a state in which they are particularly effective at presentation of alloantigen. Together our findings indicate that three components are required for Ag presentation in primary MLC: class II MHC-positive stimulator cells that have attained the appropriate state of differentiation and the presence of both IL-1 and IL-6.
Association of cytoskeletal re-organization with capping of the complement decay-accelerating factor on T lymphocytes.
Authors: Kammer G M , Walter E I , Medof M E
Published: December 2022

Recent studies have identified cell-associated proteins that are membrane anchored by glycosyl-inositol-phospholipid structures but the biologic implications of this mode of membrane attachment are incompletely understood. Among proteins anchored in this way is the decay-accelerating factor (DAF), a complement (C) regulatory factor that functions on blood cell surfaces to prevent autologous C attack. As one approach to investigate the functional consequences of glycosyl-inositol-phospholipid-anchoring of DAF in T lymphocytes, the effects of crosslinking surface DAF molecules were compared to those of crosslinking conventionally by anchored cluster of differentiation (CD) proteins. Upon incubation with anti-DAF mAb and anti-murine IgG, DAF re-distributed to a pole of the cell with a t1/2 at 37 degrees C of 4.4 min as compared to t1/2 of 3.5 to 7 min for CD3, CD4, and CD8. Re-distribution of DAF occurred independently of CD2, CD3, CD4, or CD8. Anti-DAF immunoprecipitates of membrane extracts of cells chemically cross-linked with dithiobis(succinimidylpropionate) contained only monomeric DAF. Immunofluorescent staining demonstrated clustered actin, tubulin, and vimentin beneath the capped DAF protein. Pre-treatment of cells with colchicine or 8-azidoadenosine 3',5'-cyclic phosphate, but not lumicolchicine, resulted in reduction of the t1/2 for DAF to 1 to 2.6 min. Conversely, treatment of cells with cytochalasins B or D completely blocked DAF capping. The results indicate that, upon cross-linking, glycosyl-inositol-phospholipid-anchored DAF molecules undergo capping similar to conventionally anchored CD molecules and that DAF capping is associated with cytoskeletal reorganization.
In vivo treatment with IL-1 reduces the severity and duration of antigen-induced arthritis in rats.
Authors: Jacobs C , Young D , Tyler S , Callis G , Gillis S , Conlon P J
Published: December 2022

IL-1 has been implicated in the pathogenesis of arthritis. Although IL-1 injected in vivo into normal joints results in a transient inflammatory reaction, we have shown that three weekly repetitive injections of IL-1 do not produce a progressive inflammatory condition suggestive of chronic arthritis. In fact, priming normal joints with three weekly IL-1 intraarticular injections results in a significant reduction in joint swelling and diminished histopathologic alterations/lesions caused by subsequent methylated BSA-induced arthritis. Similarly, post treatment with IL-1 intraarticular injection after arthritis induction reduced arthritic swelling and joint injury if IL-1 was given during the developing stage of arthritis. Our results suggest that IL-1 might limit arthritic inflammation and progressive cartilage destruction through an, as yet, undetermined mechanism(s). Further in vivo investigations are required to determine the therapeutic utility of IL-1 in reducing early arthritic inflammation.
A role of HLA-DQ molecules of stimulator-adherent cells in the regulation of human autologous mixed lymphocyte reaction.
Authors: Nieda M , Juji T , Imao S , Minami M
Published: December 2022

In this study, we have found that treatment of stimulator autologous adherent cells with anti-HLA-DQ mAb resulted in markedly enhanced proliferative response of T cells in human autologous mixed lymphocyte reaction system wherein T cells were cultured with autologous adherent cells at near ratio of adherent cells to T cells in peripheral blood, in which T cells minimally proliferate. However, treatment of stimulator-adherent cells with anti-HLA class I, anti-DR and anti-DP mAb had no effect on the proliferative response of T cells under the condition. It was further observed that CD4-enriched cells could significantly proliferate in the presence of autologous adherent cells either untreated or treated with anti-DQ mAb, although treatment of adherent cells with anti-DR mAb blocked proliferative response of CD4-enriched cells. Moreover, the proliferative response of CD4-enriched cells was suppressed by addition of CD8-enriched cells in the presence of untreated adherent cells, whereas the proliferative response of CD4-enriched cells could not be suppressed by CD8-enriched cells when the adherent cells in the culture were treated with anti-DQ mAb. These observations suggest that CD8 T cells are required for suppression of proliferative response of CD4 T cells to HLA-DR molecules on autologous stimulator-adherent cells, and that HLA-DQ molecules on the surface of adherent cells play an important role in the induction of suppression by CD8 T cells.