bluuebunny/crossref_metadata_2025 huggingface dataset:
Cross-reactive idiotype family observed in the phthalate-specific B cell repertoire of adult BALB/c mice: diversity of IgM compared with IgG monoclonal anti-phthalate antibodies.
Authors: Luo S C , Bankert R B
Published: December 2022

A highly conserved clonotype has been identified within the repertoire of B cells specific for the negatively charged hapten phthalate. The prototype of this phthalate-specific clonotype is a primary-response hybridoma (2E9) that produces a mu,kappa anti-phthalate antibody. The 2E9 monoclonal antibody was found to share idiotypic determinants with several other independently-derived mu,kappa and gamma 1,kappa anti-phthalate monoclonal antibodies and with a significant proportion of conventional anti-phthalate antibodies derived from all of the BALB/c mice immunized with phthalate-keyhole limpet hemocyanin. Competitive RIA analysis of the 2E9 idiotypic relatedness between primary and secondary response antibodies was consistent with the hypothesis that the primary response mu,kappa antibodies represent a conserved germ-line product, whereas the secondary response to gamma 1,kappa antibodies reflect somatic variants of the 2E9 clonotype. Further analysis with a site-specific anti-idiotype reagent suggests that the idiotypic differences between mu,kappa and gamma 1,kappa monoclonal antibodies occur at positions outside of the combining site. Fine specificity analysis of the monoclonal antibodies expressing the 2E9 cross-reactive idiotype (CRI) also supports this hypothesis. Seven to 35% of the anti-phthalate antibodies after a single immunization with phthalate-KLH and 1 to 10% of the antibodies after a second immunization express the 2E9 CRI. The 2E9 CRI was also found in several other strains of mice, and its expression was associated exclusively with anti-phthalate antibodies.
Adenosine; a physiologic modulator of superoxide anion generation by human neutrophils. Adenosine acts via an A2 receptor on human neutrophils.
Authors: Cronstein B N , Rosenstein E D , Kramer S B , Weissmann G , Hirschhorn R
Published: December 2022

Adenosine specifically inhibits superoxide anion generation by N-formyl-methionyl-leucyl-phenylalanine-stimulated neutrophils without affecting either degranulation or "aggregation." We present data that also supports the hypothesis that adenosine engages a specific cell surface receptor to mediate inhibition of stimulated neutrophils. Theophylline (10 and 100 mu M), a competitive antagonist at adenosine receptors, reversed the effects of adenosine (0.1 mu M) on superoxide anion generation by stimulated neutrophils. The adenosine analogue 5'N-ethylcarboxamidoadenosine (NECA) was a more potent inhibitor of superoxide anion generation than either N6-phenylisopropyladenosine (PIA) or adenosine, an order of potency consistent with that previously demonstrated for adenosine A2 receptors. 2-Chloroadenosine inhibited superoxide anion generation at concentrations similar to NECA. [3H]-NECA and [3H]-2-chloroadenosine bound to a single receptor on intact neutrophils. The characteristics of the receptors for [3H]-NECA and [3H]-2-chloroadenosine were similar (Kd = 0.22 and 0.23 mu M, respectively; number of binding sites = 9.31 and 11.1 X 10(3) sites/cell, respectively). NECA, 2-chloroadenosine, adenosine, and PIA inhibited binding of [3H]-NECA with a rank order similar to that for inhibition of superoxide anion generation (NECA = 2-chloroadenosine greater than adenosine greater than PIA). There was 50% inhibition of superoxide anion generation by NECA at approximately 20% receptor occupancy. Adenosine, derived from damaged tissues, may serve as a specific, endogenous modulator of superoxide anion generation by activated neutrophils through interaction at this newly described receptor on human neutrophils.
Distribution and fate of free and liposome-encapsulated [3H]nor-muramyl dipeptide and [3H]muramyl tripeptide phosphatidylethanolamine in mice.
Authors: Fogler W E , Wade R , Brundish D E , Fidler I J
Published: December 2022

The pharmacokinetics and metabolism of i.v. administered free (unencapsulated) or liposome-encapsulated hydrophilic [3H]-labeled nor-muramyl dipeptide (nor-MDP) and lipophilic [3H]-labeled muramyl tripeptide phosphatidylethanolamine (MTP-PE) were evaluated. In addition we also examined the distribution and fate of these immunomodulators subsequent to intranasal (i.n.) administration. Unique patterns of circulatory clearance, organ distribution, metabolism, and excretion were observed for each of the four preparations. Nor-MDP in saline was rapidly cleared from the circulation and excreted in the urine as intact molecules. MTP-PE dissolved in saline was cleared from the circulation at a slow rate and found within various organs as intact MTP-PE, lyso-MTP-PE, and MDP. Following the i.v. administration of nor-MDP or MTP-PE in liposomes, patterns of clearance and organ distribution corresponded to that of liposome distribution, i.e., the reticuloendothelial system. Extensive dissociation of hydrophilic nor-MDP from the carrier liposomes occurred, and the immunomodulator was recovered in the urine. In contrast, MTP-PE entrapped in liposomes was retained in target organs for the duration of the study. The i.n. instillation of radiolabeled nor-MDP or MTP-PE was associated with the accumulation of these immunomodulators in the brain. Our results demonstrate the feasibility of targeting hydrophilic and lipophilic immunomodulators to cells of the macrophage-histiocyte series.
Characterization of the interaction of human eosinophils and neutrophils with opsonized particles.
Authors: Yazdanbakhsh M , Eckmann C M , Roos D
Published: December 2022

The interaction of human eosinophils with opsonized particles was compared with that of human neutrophils. When eosinophils are stimulated with serum-opsonized zymosan particles, the lag time in H2O2 production is twice as long as found with neutrophils. Moreover, the concentration of these IgG + C3-coated particles required for optimal stimulation is about four times as high for eosinophils as for neutrophils. Under these conditions, the two cell types generate similar amounts of H2O2. However, eosinophils produce twice as much H2O2 as do neutrophils when stimulated with the soluble agent phorbol myristate acetate. Thus, although the oxidase capacity of eosinophils is larger than that of neutrophils, opsonized zymosan is a weak trigger for this activity in eosinophils. This phenomenon may be due to differences between the two cell types in the plasma membrane receptors or in the receptor oxidase transducing signal. The following are indications for the first possibility. i) IgG interacts poorly with the Fc gamma receptors on the eosinophil surface compared with those on neutrophils. This was shown by the inability of IgG-coated zymosan or IgG-coated latex to trigger any substantial H2O2 production by eosinophils unless brought into close contact with these cells by centrifugation. In contrast, neutrophils are stimulated by these particles both in suspension and in a pellet. The dissimilarity of the Fc gamma receptors on eosinophils and neutrophils was also shown with respect to antigenicity, determined by the monoclonal antibodies 3G8 and CLB-FcR-1. ii) Eosinophils contain about half as many receptors for C3b and C3bi on their surface as do neutrophils, also detected with monoclonal antibodies. The interaction of IgG subclasses with functional Fc gamma receptors on eosinophils and neutrophils showed that eosinophils release twice as much H2O2 as do neutrophils upon interaction with IgG1-, IgG2-, or IgG3-coated Sepharose beads, but this difference becomes fivefold with IgG4-coated Sepharose. This might be of relevance to the situation of chronic antigenic stimulation, e.g., in chronic schistosomiasis, in which eosinophil numbers and IgG4 antibody levels are elevated.
Immunostimulation by cytomegalovirus (CMV): helper T cell-dependent activation of immunoglobulin production in vitro by lymphocytes from CMV-immune donors.
Authors: Yachie A , Tosato G , Straus S E , Blaese R M
Published: December 2022

Cytomegalovirus (CMV) is the cause of a number of different diseases ranging from self-limited benign infections in healthy adults to life threatening illnesses among immunocompromised hosts and newborns. Suppression of cell-mediated immunity is often found in cases of acute CMV infection, and in addition, the virus may also be a potent stimulant of lymphoid cells in vivo. We studied cellular proliferation and immunoglobulin (Ig) production induced by CMV to determine its effect on human lymphocytes in vitro. The CMV that was added to cultures of lymphocytes from CMV-seronegative donors failed to induce either significant cellular proliferation or Ig production. By contrast, CMV-stimulated cultures from CMV-seropositive donors induced both prominent cellular proliferation and Ig production. B cell differentiation into Ig-secreting cells required the presence of T cells, and this T cell help was sensitive to irradiation with 2000 rad and to treatment with cyclosporin A. When T cells were depleted of OKT4+ cells with monoclonal antibody and complement, the co-cultured B cells failed to produce Ig, whereas the depletion of OKT8+ cells had no effect on the Ig-secreting cell response. Inactivation of CMV before culture did not result in a reduction of either cellular proliferation or Ig production. Thus, infection of target cells is not required for in vitro lymphocyte activation by CMV. These results demonstrate that CMV is a potent activator of B cells inducing Ig production in vitro, and that this process requires the presence of virus-specific memory T cells.
A heat-modifiable outer membrane protein carries an antigen specific for the species Yersinia enterocolitica and Yersinia pseudotuberculosis.
Authors: Ogasawara M , Kobayashi S , Arai S , Laheji K , Hill J L , Kono D H , Yu D T
Published: December 2022

The outer membranes of gram-negative bacteria are considered to be of importance in host-bacteria interaction, in protective immunity, and occasionally in subclassification within a species. In this study, the outer membranes of several strains of Yersinia enterocolitica and Y. pseudotuberculosis were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). It was found that the appearance of the major proteins depended on the temperature at which they were solubilized in SDS. A protein was identified with the use of two-dimensional gels and preparative SDS-PAGE, which was equivalent to the "heat-modifiable protein" (protein II) of other Enterobacteriaceae species. A monoclonal antibody, 4G1, was generated against an isolated preparation of this Y. enterocolitica protein. This antibody was tested with whole cell bacterial antigens of 46 individual bacterial strains. The reactive strains included only Y. enterocolitica and Y. pseudotuberculosis. In addition, the reactivity of the 4G1 monoclonal antibody preparation could be absorbed only with Y. enterocolitica and Y. pseudotuberculosis, and not with other strains of bacteria. The reactivity of this 4G1 monoclonal antibody was also tested by the Western Blot technique. Six individual strains were tested: a Y. enterocolitica serotype 0:3, a Y. enterocolitica serotype 0:9, an Escherichia coli, a Salmonella typhimurium, a Shigella flexneri, and a Klebsiella pneumoniae. The 4G1 antibody reacted with only the proteins of the two Y. enterocolitica strains. In conclusion, the equivalent of the heat-modifiable protein was present in Y. enterocolitica and Y. pseudotuberculosis. Moreover, this protein also carried a species-specific antigenic determinant.
Polymorphic class II sequences linked to the rat major histocompatibility complex (RT1) homologous to human DR and DQ sequences.
Authors: Palmer M J , Buck D A , Frelinger J A , Wettstein P J
Published: December 2022

Until recently, the analysis of Class II genes linked to the rat major histocompatibility complex, RT1, has been confined to serologic and electrophoretic analysis of their gene products. To obtain a more definitive estimate of the number and relative polymorphism of RT1 Class II sequences, we performed Southern blot analysis of rat genomic DNA employing human cDNA probes specific for Class II heavy and light chain genes. Southern blots of EcoRI and BamHI digests of genomic DNA from ten inbred strains, expressing eight RT1 haplotypes, were hybridized with the human DQ beta or DR beta cDNA that are homologous to Class II light chain sequences. Four to eight bands were observed to hybridize with the light chain cDNA: band sizes ranged from 2.5 to 28 kb. Restriction fragment patterns were polymorphic; the only identical patterns observed were those associated with RT1 haplotypes with identical RT1.B regions. The number and size of bands hybridizing with DQ beta and DR beta suggested a minimum of four light chain sequences in each haplotype. Southern blots of BamHI and EcoRI digests of genomic DNA from the same strains were hybridized with a DR alpha cDNA that is homologous to Class II heavy chain sequences. All RT1 haplotypes expressed either a 10.0-kb or 13.0-kb band when digested with BamHI, and either a 17-kb or 3.7-kb band when digested with EcoRI. Considerably less polymorphism was detected with the DR alpha probe; this observation is consistent with previously reported limited protein polymorphism of the rat equivalent of the I-E alpha subunit. The size and number of bands hybridizing with the DR alpha probe suggests a minimum of two heavy chain sequences. These observations suggest that the RT1 complex includes more Class II sequences than have been observed in serologic and electrophoretic analyses of Class II gene products. Furthermore, the level of polymorphism of RT1 Class II sequences appears to be comparable with mouse and human Class II sequences.
Presence of an antigen-specific T cell subset that forms IgE-suppressive factor and IgG-suppressive factor on antigenic stimulation.
Authors: Jardieu P , Uede T , Ishizaka K
Published: December 2022

B6D2F1 mice were given three i.v. injections of ovalbumin (OA), and antigen-specific T cell clones were established from their spleen cells. One of the FcR+ T cell clones formed IgE-binding factors on incubation with OA-pulsed syngeneic macrophages. Neither soluble antigen nor macrophages alone induced factor formation. T cell hybridomas were constructed by fusion of the antigen-specific T cell clone with BW 5147 cells. Among 11 T cell hybridomas established, six clones produced IgE-binding factors on incubation with OA-pulsed BDF1 macrophages. Mouse IgE also induced the same hybridoma to form IgE-binding factors. The majority of IgE-binding factors formed by two T hybridomas and by those produced by the parent T cell clone had affinity for peanut agglutinin but for neither lentil lectin nor Con A. These hybridomas and the original T cell clone spontaneously released glycosylation-inhibiting factor, which inhibits the assembly of N-linked oligosaccharide(s) on IgE-binding factors. On antigenic stimulation, the T cell hybridomas produced both IgE-binding factors and IgG-binding factors. The IgE-binding factors consisted of three species with m.w. of 60,000, 30,000, and 15,000. Both the 60K and 15K IgE-binding factors selectively suppressed the IgE response of DNP-OA-primed rat mesenteric lymph node cells, whereas IgG-binding factors selectively suppressed the IgG response. The results indicate that antigen-primed FcR+ T cells produced IgE-suppressive factors and IgG-suppressive factors on antigenic stimulation. However, the T cell hybridomas were not committed to suppressive activity. When the hybridomas were stimulated by antigen in the presence of glycosylation-enhancing factor (GEF), the 60K, 30K, and 15K IgE-binding factors formed by the cells selectively potentiated the IgE response. IgG-binding factors formed by the cells in the presence of GEF failed to suppress the IgG response. It appears that antigen-specific FcR+ T cells regulate the antibody response through the formation of Ig-binding factors, but that the function of the cells could be switched from suppression to enhancement, depending on the environment of the cells.
B cell immune repertoire diversifies in a predictable temporal order in vitro.
Authors: Teale J M
Published: December 2022

The appearance of functional, antigen-specific B cells was studied in an in vitro fetal organ culture system in the absence of environmental influences associated with circulation and cell migration. In this way the B cell diversification process could be analyzed when genetic influences were dominating. By using this system in combination with the splenic focus assay, the frequency of developing B cells responsive to a number of hapten probes was measured. The results indicate that B cell diversification in vitro, in the apparent absence of many environmental influences, results in the appearance of antigen-responsive B cells in a predictable, temporal order. The results suggest that the acquisition of the expressed repertoire to a large extent is genetically controlled.
Mitogen-like monoclonal anti-actin antibodies.
Authors: Rosenblatt H M , Parikh N , McClure J E , Meza I , Hwo S Y , Bryan J , Shearer W T
Published: December 2022

Monoclonal antibodies (IgM kappa) have been produced to actin isolated electrophoretically from L cell extracts. These monoclonal anti-actin antibodies bind to intact L cells and modulate DNA synthesis and cell proliferation, much like affinity-purified polyclonal rabbit antibody to the same Mr 42,000 actin. In addition, monoclonal antibodies specific for actin from Entamoeba histolytica also bound to and modulated the growth of L cells. A monoclonal antibody directed against a neuroblastoma surface antigen did not produce stimulation of L cells, and the binding activity of anti-actin monoclonal antibody to L cells was removed by absorption with actin covalently coupled to Sepharose. These observations demonstrate the specificity of interaction between the anti-actin monoclonal antibodies and the surface of intact L cells. We conclude that a surface actin-like molecule on the L cell, when bound by specific monoclonal antibody, initiates a stimulatory signal which results in enhanced cellular metabolism.
GVHR elicited by products of class I or class II loci of the MHC: analysis of the response of mouse T lymphocytes to products of class I and class II loci of the MHC in correlation with GVHR-induced mortality, medullary aplasia, and enteropathy.
Authors: Piguet P F
Published: December 2022

A lethal graft-vs-host reaction (GVHR) was elicited by the injection into irradiated (700 rad) mice, reconstituted with T-depleted bone marrow cells (BM), of T lymphocytes incompatible for different loci of the major histocompatibility complex (MHC). The number of T cells needed to kill more than 50% of the recipients by day 40 was about 10(6) for GVHR elicited across the product of the K, D, or E locus, but about 10(5)--10--fold less-when the A locus was involved. The mortality was associated with a medullary aplasia in all strain combinations, but enteropathy was observed only in GVHR elicited by the products of class II, and not class I, loci. Mortality and medullary aplasia were diminished or absent in recipients reconstituted with BM cells from T cell donors instead of cells of the host genotype, which suggests a direct (cytolytic) T-hematopoietic cell interaction. Lymphoproliferation was evident within the host spleen and lymph node 5 days after injection of T lymphocytes incompatible for class II but not class I loci. Spleens from mice suffering from a lethal GVHR were examined by culture in limiting dilution to evaluate the frequency of anti-host T cells and to derive anti-host T cell clones and lines, whose properties were explored. In the GVHR elicited across the A or E region of the MHC, examined between days 7 and 19, a high frequency (10(-2] of anti-host cells was observed. The polyclonal cell lines isolated (16) all displayed MLR responsiveness, antigen-driven IL 2 production, and cytolysis for LPS blasts of the host genotype. However, among 13 clones isolated, two categories were observed: Lyt-2-, which were MLR responders and IL 2 producers (four of 13), and Lyt-2+, which were cytolytic but neither MLR responders nor IL 2 producers (nine of 13). In the GVHR elicited by the K or D region, examined between days 7 and 90, the frequency of anti-host cells was low (10(3) to 10(4], with a tendency to decrease during the progression of the disease. The lines (11) or clones (26) isolated from different mice were all Lyt-2+ and strongly cytolytic but proliferated poorly and produced no IL 2 in MLR. These findings suggest that the Lyt-2+ lymphocytes, recognizing the products of the class I loci, function in vivo without proliferation and without requiring helper T cells. Cell lines specific for class I or class II loci of the MHC produced interferon and colony-stimulating factors.
Molecular associations of class II MHC antigens in mitogen-stimulated B cells.
Authors: Wolfert R L , Goodman M G , Weigle W O
Published: December 2022

Previously, we showed that murine B cell membrane proteins undergo rearrangements in the plasma membrane to form new molecular associations in response to mitogenic stimulation. These complexes were covalently stabilized by photoreactive cross-linking agents and were analyzed by SDS PAGE. We have now identified certain complexes that involve class II MHC products, the Ia antigens. Upon stimulation of B cells with LPS, Ia surface molecules (as identified by radioimmunoprecipitation with polyclonal anti-Ia antiserum) enter into a molecular complex with a 95-kd membrane-associated protein (p95) to form a 200-kd complex that may be stabilized by the cross-linking agent dithiobisphenylazide (DTPA). This molecular association is not observed upon stimulation with mitogenic anti-Ig reagents, nor with the polyclonal B cell activator 8-bromoguanosine. p95 is not a disulfide-linked molecule itself, and by separate immunoprecipitation experiments we have established that it is not a component of surface Ig, transferrin receptor, the B cell Fc receptor, or CR1, the receptor for complement component C3b. Further analysis of the association of Ia antigens with surface proteins, with the use of monoclonal antibodies directed against I-A or I-E, has demonstrated that each subregion gene product forms a unique molecular association. Precipitation of radiolabeled lysates from LPS-activated B cells with anti-I-A reveals the aforementioned association with p95. In contrast, the I-E antigen apparently forms complexes with a multimer of a 15-kd protein to give complexes of 45, 60, 75, and 90 kd. When analyzed by two-dimensional diagonal gels (nonreducing/reducing), only the I-E bands are revealed by autoradiography, indicating that the putative p15 that associates with I-E may not be accessible to surface labeling. The disparate molecular associations for I-A and I-E suggest that the formation of these distinct protein complexes may be functionally related to a different role in the process of cellular activation for each of these Ia subregion gene products.
Molecular events in B cell activation. I. Signals required to stimulate G0 to G1 transition of resting B lymphocytes.
Authors: Monroe J G , Kass M J
Published: December 2022

Anti-immunoglobulin antibodies (anti-Ig) can stimulate a majority of resting B cells via their receptor Ig. Evidence suggests that the signals generated after this ligand-receptor interaction may be transduced via hydrolysis of inositol phospholipids. In other systems, the ability of inositol phospholipid hydrolysis to link receptor-ligand interactions to subsequent activational events has been suggested to relate to the ability of metabolic intermediates of this hydrolytic process to facilitate activation of protein kinase C and mobilization of Ca+2. In this study, we investigated the importance of protein kinase C and Ca+2 mobilization in the signaling mechanism by which anti-Ig drives B cells to undergo G0 to G1 transition. Our results show that pharmacologic inhibition of either protein kinase C activity or channel-mediated Ca+2 influx completely abrogates the increase in RNA synthesis associated with B cell activation after stimulation by anti-Ig. This suggests that pathways leading to both protein kinase C activation and elevation of intracellular Ca+2 are critical for receptor Ig-mediated G0 to G1 transition. Furthermore, studies in which anti-Ig-induced signaling could be bypassed by directly facilitating Ca+2 mobilization and protein kinase C activation using Ca+2 ionophore and phorbol diester show that these events are sufficient to drive the majority of resting B cells into G1 in the absence of additional signaling from accessory cells or extra-cellular factors. However, like anti-Ig-induced stimulation, Ca+2 ionophore and phorbol diester are relatively inefficient in driving B cells that have entered G1 into S phase. We discuss the relevance of these results towards the transduction mechanism linking B cell membrane-associated Ig-generated signals with subsequent activation events.
Characterization of circulating and cutaneous IgA immune complexes in patients with dermatitis herpetiformis.
Authors: Hall R P , Lawley T J
Published: December 2022

Dermatitis herpetiformis (DH) is a chronic, blistering skin disease characterized in part by deposits of IgA at the dermal-epidermal junction. Eighty-five percent of DH patients have granular IgA deposits and have an associated gluten-sensitive enteropathy (GSE). In contrast, 15% of DH patients have a linear pattern of IgA deposits and no associated intestinal abnormality. Although circulating IgA antibodies against skin are not present in these patients, 40% of DH patients do have IgA-containing circulating immune complexes (IgA-CIC). The role and origin of the cutaneous IgA and the IgA-CIC in patients with DH are unknown; however, the association of GSE with the granular IgA deposits suggests that a mucosal immune response may be important in the pathogenesis of DH. We have characterized the IgA subclass composition of the cutaneous IgA deposits in patients with DH, and have isolated and characterized the IgA-CIC from these patients. Twenty-nine of 29 patients with DH and granular IgA deposits were found to have only IgA1 deposits. Ten of 11 patients with linear IgA deposits also had only IgA1 deposits; one of 11 had IgA2 deposits. Isolated IgA-CIC from the sera of eight patients with DH and granular IgA deposits were found to contain both IgA1 (58% +/- 5, mean percent of total IgA +/- SEM) and IgA2 (42% +/- 5), as were IgA-CIC from two patients with ordinary GSE without cutaneous IgA deposits. The IgA subclass composition of the isolated immune complexes was significantly different from the serum IgA1 and IgA2 composition (serum IgA1 = 76% +/- 6; IgA2 = 24% +/- 5, p less than 0.025, Student's t-test), and suggests that the IgA-CIC may arise from gut-associated lymphoid tissue (GALT). Sequential anti-IgA1 absorption of serum which contained IgA-CIC did not remove all the IgA-CIC, suggesting that the complexes circulate as separate IgA1 and IgA2 complexes. The finding of IgA1 alone in the skin of patients with DH suggests that the cutaneous IgA may not arise from GALT, or that IgA1, possibly arising in GALT, is preferentially bound to DH skin. Because IgA-containing CIC which contain both IgA1 and IgA2 were found in the serum of patients with DH and with ordinary GSE, it seems unlikely that IgA-containing CIC are responsible for the cutaneous IgA deposits seen in DH.
Disease-associated loss of erythrocyte complement receptors (CR1, C3b receptors) in patients with systemic lupus erythematosus and other diseases involving autoantibodies and/or complement activation.
Authors: Ross G D , Yount W J , Walport M J , Winfield J B , Parker C J , Fuller C R , Taylor R P , Myones B L , Lachmann P J
Published: December 2022

Although surface membrane density of complement receptor type one (CR1) on erythrocytes (E) is probably an inherited trait among normal individuals, recent evidence from our laboratories suggests that the reduced number of CR1 per E observed in patients with systemic lupus erythematosus (SLE) results from acquired as well as genetic factors. In the present investigation, the number of CR1 per E was quantitated with 125I-monoclonal anti-CR1 and was found to vary inversely with disease activity in patients with SLE who were followed serially for as long as 14 mo. Although evidence for E surface-bound immune complexes or fixed C3b/iC3b was not obtained, periods of disease activity and low amounts of CR1 per E correlated with the presence of 100 to 800 molecules per E of fixed C3dg fragments (less than 100 C3dg per E in normal subjects). Reduced CR1 and excess fixed C3dg on E also were observed in patients with other disorders associated with complement activation, including chronic cold agglutinin disease, autoimmune hemolytic anemia, paroxysmal nocturnal hemoglobinuria (PNH), Sjögren's syndrome, and mycoplasma pneumonia. A significant negative correlation (r = -0.498) between CR1/E and fixed C3dg/E was demonstrable in 255 individual assays evaluated by regression analysis. CR1 decreased and fixed C3dg increased during active disease; the converse was obtained during remission. In patients with active SLE, both serum complement activity and E CR1 decreased, whereas fixed C3dg fragments increased. By piecewise linear regression analysis, the appearance of 100 to 400 C3dg molecules on patients' E corresponded to a 27 to 60%, reduction in the number of CR1 per E (p less than 0.0002), confirming that fixation of C3 to E was correlated with a loss of CR1. In patients with PNH, low values for CR1 were observed on moderately complement-sensitive PNH type II E in association with increased fixed C3 fragments; however, the markedly complement-sensitive PNH type III E had essentially normal amounts of CR1 and bore little fixed C3. The addition of soluble DNA/anti-DNA immune complexes to normal blood generated levels of fixed C3dg fragments on E comparable to those observed on E from patients with SLE. Kinetic experiments indicated that C3b was fixed to E during the process of immune complex binding and release from E CR1, and that this fixed C3b was subsequently degraded rapidly to fixed iC3b and more slowly to fixed C3dg without the loss of CR1 that occurs in vivo.(ABSTRACT TRUNCATED AT 400 WORDS)
Functional integrity of cytokineplasts: specific chemotactic and capping responses.
Authors: Dyett D E , Malawista S E , Van Blaricom G , Melnick D A , Malech H L
Published: December 2022

Cytokineplasts (CKP) are motile, membrane-bound, anucleate, granule-poor cytoplasmic fragments that are induced from human blood polymorphonuclear leukocytes (PMN) by the brief application of heat. We examined CKP with respect to specific chemotactic and capping responses, the presence of the N-formyl-peptide chemotactide receptor, and evidence of respiratory burst activity and compared them with CB-cytoplasts, which are fragments created by the centrifugation of cytochalasin B (CB)-treated PMN at high speeds. Under agarose, CKP responded chemotactically to both N-formyl-methionyl-leucyl-phenylalanine (fmlp) and zymosan-activated serum; CB-cytoplasts responded to neither chemoattractant. Despite the functional differences, both fragments retained N-formyl-peptide receptors as measured by affinity labeling with N-formyl-norleu-leu-phe-norleu-125I-tyr-lys and autoradiography of dried SDS-PAGE gels. For studies of capping we used a murine monoclonal antibody, PMN7C3, which binds a specific, widely distributed membrane component of intact PMN, and on warming, promptly induces capping of ligand-receptor complexes. Rhodamine-conjugated PMN7C3 at 4 degrees C labeled the surface of CKP homogeneously. As the CKP warmed to 37 degrees C, label became concentrated in small fluorescent caps at the rear of migrating fragments. Although CB-cytoplasts also bound the fluorochromed antibody homogeneously in the cold, on warming they were unable to concentrate the label normally. With respect to respiratory burst activity, the situation in the two fragments was reversed: CKP did not generate superoxide anion when stimulated either with phorbol myristate acetate or with fmlp after pretreatment with CB; CB-cytoplasts, as noted earlier by other investigators, did. These two types of cytoplasts with markedly different capabilities have complementary roles in the analysis of PMN function.
Prophylactic immunization against experimental leishmaniasis. IV. Subcutaneous immunization prevents the induction of protective immunity against fatal Leishmania major infection.
Authors: Liew F Y , Hale C , Howard J G
Published: December 2022

Durable immunity against fatal L. major infection in genetically susceptible mice can be induced by immunization with 150,000-rad irradiated or heat-killed promastigotes administered i.v. or to a lesser extent i.p. Conversely, subcutaneous (s.c.) and intramuscular (i.m.) injections are not only totally ineffective but generally increase susceptibility to and enhance the progression of the disease, leading to earlier mortality. This detrimental effect is particularly evident with lower infecting challenge doses. Disease exacerbation is apparent in mice given 4 X s.c. injections of as few as 2 X 10(4) irradiated promastigotes, but it appears most potent after doses of 2 X 10(7). When mice given 4 X s.c. injections were subsequently immunized i.v. with 2 X 10(7) irradiated promastigotes, they failed to develop any evidence of protection against infection with 2 X 10(5) promastigotes, whereas mice given i.v. immunization alone were strongly protected. Thus, s.c. injections are capable of blocking the prophylactic effect of i.v. immunization with irradiated parasites. This inhibitory effect can be achieved with a single s.c. injection, although rather less potently than with four, and is even effective against four repeated weekly i.v. immunizations. Once induced, the effect persists undiminished after 100 days. A weaker effect is also inducible by s.c. injection given after i.v. immunization. The blocking effect of s.c. injection is not dependent on continuing viability of the promastigotes, as it can be induced equally readily with heat-killed, formalin-fixed, or sonicated parasites. The phenomenon extends to mouse strains genetically resistant as well as susceptible to L. major infection and, in congenic mice of BALB background, is independent of the major histocompatibility (H-2) gene complex.
Schistosoma mansoni: detection by monoclonal antibody of a 22,000-dalton surface membrane antigen which may be blocked by host molecules on lung stage parasites.
Authors: Harn D A , Mitsuyama M , Huguenel E D , David J R
Published: December 2022

Monoclonal antibody M.2 binds to the surface membranes of cercariae and developing schistosomula. This antibody was generated from mice immunized with membrane-enriched extracts of mechanically transformed schistosomula. The antigen detected by M.2 was shown to persist on developing schistosomula for at least 96 hr post-transformation. M.2 also bound to the surface of living, cultured lung worms but not to freshly harvested lung worms. The ability of M.2 to bind to cultured lung worms coincided with the loss of host H-2 from the parasite surface. The apparent m.w. of the antigen was 22,000; an antigen with the same apparent m.w. was immunoprecipitated from cercariae, schistosomula, lung worms, and adult worms.
Structure and expression of two porcine genomic clones encoding class I MHC antigens.
Authors: Satz M L , Wang L C , Singer D S , Rudikoff S
Published: December 2022

Two nonallelic porcine class I MHC (SLA) genes have been isolated and characterized. Both genes are expressed in mouse L cells, directing the synthesis of class I SLA molecules that carry common monomorphic determinants but are serologically distinct. The corresponding DNA sequences have been determined. The organization of both of these genes is similar to that of other class I genes: a leader exon, three exons encoding extracellular domains, a transmembrane exon, and three intracytoplasmic exons. The two genes are highly homologous in both exon and intron segments, with average homologies of 88% and 80%, respectively. Nucleotide changes in exon 2 are clustered, whereas those in the other exons are dispersed throughout. Comparison of the swine DNA sequences with class I genes from other species reveals a generally high conservation of exons 2, 3, 4, and 6 with lower homology in the remaining protein-encoding domains. Introns are markedly less well conserved, although moderate homology is found between swine and human class I MHC genes in both introns and 3' flanking regions. Taken together with comparisons of the deduced protein sequences, these data indicate an order of swine greater than human greater than rabbit greater than mouse in the relationship of class I genes.
Cross-reactive cellular and humoral immunity to carcinogen-induced chicken fibrosarcomas. II. Effect of prior immunization with transplantable tumors on primary tumor incidence.
Authors: Edelman A S , Xue B , Galton J E , Sanchez P , Thorbecke G J
Published: December 2022

Primary carcinogen-induced (7,12-dimethyl-benz[a]anthracene; DMBA) tumor-bearing SC chickens (B2/B2) frequently showed antibodies in their sera which reacted with cells from their autochthonous tumors, chicken embryo fibroblasts (CEF), tumor cells from some transplantable tumor lines, and from approximately 10% of other primary tumors. Similar results were obtained by ELISA on glutaraldehyde-fixed cells and by immunofluorescence on viable cells. The serum antibody reactivity could be removed by absorption with CEF but not with non-cross-reacting primary tumor cells or a variety of normal tissues. Although sera from normal chickens never showed significant reactivity, a high percentage of sera from chickens that had been injected with DMBA but failed to develop detectable tumors showed antibody activity to a transplantable DMBA-induced tumor and to CEF. On the basis of previously established cross-reactivity patterns in protective immunity to transplantable carcinogen-induced fibrosarcomas, attempts were made to protect against chemical carcinogenesis by prior immunization with selected DMBA-induced transplantable tumors. Tumor-immune chickens showed a significant decrease in the development of tumors during the first 3 mo after injection of DMBA (p = 0.001) or methylcholanthrene (p = 0.033) when compared to controls. This resistance to tumor induction in immune chickens was correlated to the degree of tumor immunity to the immunizing tumor present 1 mo after carcinogen injection (p = 0.046). There was, however, no detectable difference in the incidence of tumors arising later than 3 mo after carcinogen injection. The reduction in tumor incidence in immune as compared to control chickens at 5 mo was therefore less striking than the reduction seen at 3 mo. Immunization with CEF and adjuvants or with adjuvants alone afforded no protection to tumor induction.
Presentation of Class I antigens on T cells can induce the generation of antigen-specific CTL.
Authors: Zier K S , Pickard A R
Published: December 2022

Cytotoxic T lymphocyte (CTL) lines generally require a source of specific antigen to continue to proliferate in vitro. We previously showed that populations of mononuclear cells grown in medium containing interleukin 2 (IL 2) and composed largely of activated T cells were able to present Class I alloantigen to CTL lines. On the basis of these findings we were interested to know whether T cells themselves were able to present antigen or whether this was a function of the small number of contaminating non-T cells. To answer this question, populations of activated or resting mononuclear cells were rigorously depleted of non-T cells before use as antigen-presenting cells. We observed that populations composed of greater than 99% T cells were able to support the differentiation of antigen-specific CTL. These results were confirmed by using cells from an established T cell line. The proliferation of the same lines, however, was less than that of lines grown in the presence of antigen-presenting cells containing some non-T cells. These results suggest that although T cells can present Class I alloantigens to CTL, they may be less effective in triggering cell division than populations containing a source of non-T cells.
Postnatal liver hemopoiesis in mice: generation of pre-B cells, granulocytes, and erythrocytes in discrete colonies.
Authors: Grossi C E , Velardi A , Cooper M D
Published: December 2022

Morphologic analysis of hemopoietic tissue in mouse liver reveals the persistence of erythropoietic, granulopoietic, and lymphopoietic activity for approximately 2 wk after birth. Near the end of the first postnatal week, we noted a remarkable reorganization of the hemopoietic cells that was characterized by a transition from a diffuse distribution of mixed erythroid, myeloid, and lymphoid elements to a focal pattern of discrete hemopoietic colonies scattered among the cords of hepatic parenchymal cells. Each hemopoietic focus contained cells progressing along a single differentiation pathway (i.e., erythroid, myeloid, or lymphoid cells). Megakaryocytes were seen as solitary cells surrounded by hepatocytes. This pattern of colonization was observed in all strains of mice examined. In the livers of mice with known hemopoietic defects, however, differences were found in the duration of postnatal hemopoiesis. Accessory cells with macrophage-like features were consistently observed in erythropoietic foci, but were rarely seen in lymphoid foci. The latter were formed by pre-B cells identifiable by the presence of cytoplasmic mu-heavy chains and the absence of light chain expression. The occurrence of discrete colonies of erythroid, myeloid, and pre-B lymphoid cells in the postnatal liver suggests that each is derived from a single, committed precursor cell. This anatomical compartmentalization according to cell type offers a useful model system for analysis of hemopoietic differentiation and of the generation of clonal diversity among B lineage cells.
Suppression and contrasuppression in the induction of contact sensitivity by the administration of cellbound antigen-antibody complexes.
Authors: Ptak W , Bereta M , Ptak M , Iverson G M , Green D R
Published: December 2022

The tolerogenic signal produced by the i.v. injection of haptenated peritoneal exudate cells can be converted to an immunogenic signal by treating the cells with antibody to the hapten before administration. We examined this phenomenon and found that immunity induced by antigen-antibody complexes, as opposed to skin sensitization, is resistant to suppressor T cell influences. This resistance to suppression is due to the activation of an I-J+, Ly-1 T cell population which adheres to the Vicia villosa lectin, all characteristics of contrasuppressor T cells. Because haptenated cells can induce immunity if injected subcutaneously or into cyclophosphamide-pretreated recipients (thereby avoiding the induction of suppressor cells), we suggest that the activation of contrasuppressor cells by antigen-antibody complexes overrides suppressive influences in the host, allowing immunity to become dominant. The possible roles of suppression and contrasuppression in channeling the effector arm of the immune response (e.g., contact sensitivity vs humoral immunity) are discussed.
Activation through CD3 molecule leads to clonal expansion of all human peripheral blood T lymphocytes: functional analysis of clonally expanded cells.
Authors: Weber W E , Buurman W A , Vandermeeren M M , Raus J C
Published: December 2022

Monoclonal antibodies directed against CD3, a T cell-specific surface molecule essentially required for activation of these cells, are highly mitogenic for resting human peripheral blood T lymphocytes. A predetermined optimal concentration of anti-CD3 monoclonal antibody WT32 was employed to activate T cells cultured in limiting-dilution microcultures containing irradiated feeder cells and exogeneous interleukin 2. Frequencies of cells triggered into clonal expansion by WT32 under these culture conditions were 0.57 to 0.72 and 0.90 to 1.10 in peripheral blood mononuclear cells and E rosette-positive cells, respectively. It appeared that WT32 could induce virtually every human peripheral blood T lymphocyte to expand into a clonal progeny of 5 to 40 X 10(4) cells in 14 to 18 days of culture. This progeny was tested for cytolytic effector function with 51Cr-labeled murine P815 targets in the presence of PHA to detect all cytotoxic T lymphocytes (CTL) regardless of specificity, and was also assayed for natural killer like activity against K562 target cells. Frequencies of cells in the human peripheral blood T cell compartment giving rise to a clonal progeny expressing CTL function was 1/3, whereas 1/6 to 1/5 expanded into effector cell populations possessing NK activity. Frequency analysis of CD4-positive and CD8-positive populations, activated by WT32 in limiting dilution microcultures, demonstrated that 1 to 6% of the CD4-positive and 100% of the CD8-positive peripheral blood T lymphocytes expanded into CTL.
Surface marker characterization of EBV target cells in normal blood and tonsil B lymphocyte populations.
Authors: Aman P , Gordon J , Lewin N , Nordström M , Ehlin-Henriksson B , Klein G , Carstensson A
Published: December 2022

Human FACS-sorted B lymphocyte subpopulations were investigated for their susceptibility to immortalization by Epstein Barr virus (EBV). Only B cells reacting with the monoclonal antibody B2 were immortalized, whereas cells reacting with anti-human IgG or the monoclonal antibody BB2 were not responding. Cells positive or negative for IgM, IgD, Burkitt's lymphoma antigen (BLA), BB1, and HB2 were all transformed by EBV.
Interleukin 2 acts directly on a Tac-positive cloned B cell line established from a patient with adult T cell leukemia.
Authors: Arima N , Daitoku Y , Hidaka S , Tanaka H , Katsuki T
Published: December 2022

A Tac-positive B cell line termed K3B was established from a patient with adult T cell leukemia (ATL). This cell line had EBNA antigen and human T cell leukemic virus (HTLV) provirus besides B1 antigen and surface immunoglobulin. A cloned Tac-positive B cell line termed K3B01 was obtained from K3B by the limiting dilution method. The K3B01 cells were shown to absorb IL 2 activity in a tonsillar IL 2 preparation. By using this cloned cell line and a purified recombinant IL 2 preparation, it was shown that the proliferation of K3B01 cells was enhanced by the addition of recombinant IL 2. Moreover, this response was inhibited by anti-Tac antibody. These results demonstrate definitively that IL 2 acts directly on B cells through IL 2 receptors on them.
Effect of antibody excess on the size, stoichiometry, and DNAse resistance of DNA anti-DNA immune complexes.
Authors: Burdick G , Emlen W
Published: December 2022

The binding of antibodies to DNA was examined under conditions of increasing antibody excess. DNA anti-DNA immune complexes (IC) formed at increasing antibody to DNA ratios were digested with excess DNAse I, and the DNAse-resistant (protected) IC were analyzed. With increasing antibody excess, the size of the IC that were resistant to DNAse digestion increased, and the size of the protected DNA within the IC also increased. This suggested that IgG molecules could bind in close proximity along the DNA molecule, preventing access of DNAse to the DNA between adjacent IgG. To further define the binding of adjacent IgG, DNAse digested IC containing one or two IgG were isolated, and the DNA contained within these IC was analyzed on DNA sequencing gels. Binding of a single IgG to DNA resulted in the protection of a DNA fragment 35 to 45 base pairs (bp) long, corresponding to the distance between binding sites of a single IgG molecule. Binding of two IgG to DNA protected a DNA fragment 50 to 60 bp long, 1 1/2 times the size of the fragment protected by one IgG. These data suggest that in conditions of Ab excess, IgG molecules can interdigitate along the DNA molecule, resulting in small, stable, DNAse-resistant IC of high antibody density.