bluuebunny/crossref_metadata_2025 huggingface dataset:
IFN-treated neuroblastoma cell lines remain resistant to T cell-mediated allo-killing, and susceptible to non-MHC-restricted cytotoxicity.
Authors: Main E K , Monos D S , Lampson L A
Published: December 2022

Neuroblastoma cell lines can have very low MHC Ag expression. The cell lines are insensitive to allo-killing by primed CTL, but are sensitive to non-MHC-restricted cytotoxicity. IFN-gamma increased class I expression, but the cells remained insensitive to CTL. Susceptibility to nonrestricted effectors was preserved. Class I+ glioma cell lines behaved similarly. The CTL resistance was localized to the recognition phase. Neuroblastoma lines did not form conjugates with primed T cells, but were lysed if they were coupled to the effectors via lectins. The levels of class I expression, and resistance to CTL, were constant over a range of IFN doses. HLA-A,B,C structure and distribution were studied more intensively on one cell line, CHP-100. HLA-A2 and -A3 were present on greater than or equal to 99% of the cells, in a unimodal distribution. After IFN treatment, the levels were similar to B cell controls. In two-dimensional gel electrophoresis, the molecules co-migrated with those of B cell controls. The defect may thus be in accessory proteins that are necessary for T cell recognition or binding, rather than in the structure or distribution of the HLA-A,B,C proteins.
CD4 positive Leu-8 negative helper-inducer T cells predominate in the human intestinal lamina propria.
Authors: Kanof M E , Strober W , Fiocchi C , Zeitz M , James S P
Published: December 2022

The regulatory function of peripheral blood CD4 T cells correlates with the presence or absence of the membrane glycoprotein recognized by anti-Leu-8 antibody; CD4,Leu8- T cells help Ig synthesis and CD4,Leu-8+ T cells suppress Ig synthesis. In contrast to CD4 T cells from the peripheral blood and organized gut-associated lymphoid tissues, intestinal lamina propria CD4 T cells were found to have diminished expression of the Leu-8 Ag. Therefore, studies were performed to determine whether the decreased expression of the Leu-8 Ag on lamina propria CD4 T cells correlates with a difference in the ability of peripheral blood and lamina propria CD4 T cells to regulate PWM-stimulated Ig synthesis. At high T cell to non-T cell ratios, the helper function of lamina propria CD4 T cells was significantly higher than that of peripheral blood CD4 T cells. When CD4 T cells were incubated with anti-Leu-8 antibody, the suppressor function of peripheral blood CD4 T cells was increased, but lamina propria CD4 T cells did not suppress Ig synthesis. No difference was found between the helper function of CD4,Leu-8- T cells and the suppressor function of CD4, Leu-8+ T cells isolated from either the peripheral blood or the lamina propria. Thus, the difference in the regulatory function of CD4 T cells from the peripheral blood and the lamina propria is due to the quantitative difference in CD4,Leu-8+ T cells in these sites. Consequently, the intestinal lamina propria is a site enriched in CD4,Leu-8- T cells which predominantly mediate help for Ig synthesis.
Evidence against expression of an endogenous murine leukemia virus causing cellular resistance to lysis by activated macrophages.
Authors: Gooding L R , Taylor J R , Laster S M , Wehrly K , Chesebro B , Brickell P M , Latchmann D S , Rigby P W
Published: December 2022

In previous studies we observed that resistance of murine SV40-transformed fibroblast cell lines to cytolysis by activated macrophages was frequently associated with cellular expression of the gp70 of an endogenous ecotropic murine leukemia virus (MuLV). The work described here was initiated to test directly for a causative relationship between MuLV expression and resistance to lysis by macrophages. Northern blot analysis revealed that macrophage-resistant cells contain full length retroviral RNA. A panel of mAb which distinguish among host-range classes of MuLV detected only a non-recombinant ecotropic gp70 in these cells. The ecotropic MuLV from two independently derived macrophage resistant cells were isolated by limiting dilution cloning on Mus dunii fibroblasts. These viruses were then used to infect macrophage-sensitive cell lines and the resultant MuLV-positive cells tested for sensitivity to macrophage cytolysis. The MuLV-infected lines remained highly sensitive to macrophage lysis despite their high levels of cell surface gp70 and release of infectious MuLV. Thus, although we cannot rule out the possibility that MuLV or a product thereof is necessary for development of macrophage resistance in transformed cells, expression of MuLV per se is not sufficient to create the resistant phenotype.
Differential L chain expression in the antibody responses to phosphorylcholine of adult bone marrow or peritoneum-derived B lymphocytes.
Authors: Cazenave P A , Martinez C , Coutinho A
Published: December 2022

Lethal irradiation of adult BALB/c mice followed by reconstitution with autologous bone marrow results in loss of T15 Id and IdX expression in the responses to phosphorylcholine (PC) and alpha(1-3)-dextran, respectively. T15 Id, but not IdX expression can be reconstituted with low numbers of syngeneic, T cell-depleted peritoneal resident cells. All three groups of mice produce comparable titers of specific anti-PC and anti-dextran antibodies. The inability of adult bone marrow-reconstituted BALB/c mice to produce T15 Id+ antibodies is not due to differential VH-gene expression in bone marrow or peritoneum-derived B cells. Thus, the levels of T15 VH in total serum Ig and in anti-PC antibodies are similar in all groups of mice. Furthermore, IEF patterns of T15 VH-associated L chains directly demonstrate differential Vk repertoire expression in bone marrow and peritoneum-derived B cells.
Mouse fetal thymus lobes cultured in IL-2 generate CD3+, TCR-gamma delta-expressing CD4-/CD8+ and CD4-/CD8- cells.
Authors: Ceredig R , Medveczky J , Skulimowski A
Published: December 2022

Whole, undisrupted, 14-day fetal mouse thymus lobes were liquid-cultured in medium supplemented with 10 U/ml rIL-2. The cells that emerged from these fetal thymus lobes grew in an IL-2-dependent manner and showed non-MHC-restricted cytolytic activity. By two-color flow microfluorimetric analysis they could be subdivided into CD4-/CD8+ and CD4-/CD8- subpopulations, both of which contained CD3+ cells. Northern analysis of total cellular RNA revealed full-length transcripts of gamma- and delta-message, predominantly the truncated (1.0 kb) beta- and no detectable alpha-message. Taken together, these results show that by culturing 14-day fetal thymus lobes in IL-2, in the absence of deliberate mitogen stimulation, CD3+, TcR-gamma delta-expressing CD4-/CD8+ and CD4-/CD8- T cells are obtained. Such cells may represent the precursors of similar cells found outside the thymus in adult mice.
Expression of lymphocyte adhesion receptors for high endothelium in primates. Anatomic partitioning and linkage to activation.
Authors: Willerford D M , Hoffman P A , Gallatin W M
Published: December 2022

Glycoproteins of 90 to 95 kD Mr are involved in adhesion to high endothelium and migration into secondary lymphoid tissues in several species. Recent evidence indicates that in primates, one type of these molecules may be subsumed under the CD44 grouping of lymphocyte differentiation Ag. Flow cytometric analysis of circulating macaque lymphocytes for expression of these structures revealed a prominent bimodal distribution, defining two subpopulations with a 5- to 10-fold difference in immunofluorescence staining intensity. Studies of lymphocytes from different anatomic compartments revealed marked differences in the relative numbers of these two phenotypes: splenic and peripheral blood lymphocytes were mostly CD44hi, whereas thoracic duct lymphocytes, which have recently exited lymph nodes and Peyer's patches, were predominantly CD44lo, suggesting that these subsets may have different migratory behavior in vivo. Activated lymphocytes, as defined by light scatter measurements, expression of IL-2-R, and CD45R levels, were all CD44hi. Simultaneous three parameter flow cytometric determination of CD44 and CD45R expression, and cell-cycle analysis with 7-amino actinomycin D further demonstrated that intrinsically cycling cells were contained in the CD44hi, CD45R+ subset. After stimulation of CD44lo lymphocytes in vitro with cross-linked anti-CD3 antibodies and PMA, CD44 expression markedly increased. These data indicate that CD44 up-regulation is an early event in T lymphocyte activation in vivo, and support the hypothesis that patterns of lymphocyte traffic are regulated in concert with cell activation, possibly by differential expression of CD44.
Quantitative analyses of immune network components.
Authors: Lacy M J , Dombrink-Kurtzman M A , Voss E W
Published: December 2022

Polyclonal immune network antibodies were quantitated and characterized in a syngeneic BALB/c murine system. Immunizations of BALB/c antifluorescein mAb 9-40 conjugated to keyhole limpet hemocyanin, produced anti-Id (anti-9-40, 39 to 190 micrograms/ml) as well as anti-fluorescein (anti-Fl, 12 to 109 micrograms/ml). Separately, immunizations of polyclonal anti-9-40, developed significant anti-Fl serum levels in the secondary (2 degrees) response (50 to 270 micrograms/ml), which decreased in the 3 degrees response (50 to 180 micrograms/ml) and thereafter, although levels of 9-40 idiotypically related antibodies increased. Polyclonal 2 degrees anti-anti-9-40 exhibited variant anti-Fl active sites, was antigenically more cross-reactive than polyclonal 2 degrees anti-Fl, but did not exhibit affinity maturation for fluorescein relative to 1 degrees anti-anti-9-40. In addition, the 9-40 idiotype constituted a small (less than 1.0%) percent of the 2 degrees and 3 degrees anti-Fl (ab1) immune response. When viewed within the context of an antigenic system that possesses widely diverse idiotypy, continued introduction of polyclonal anti-Id appears eventually to: 1) induce polyclonal ab3 with quantitative expression of idiotypically related antibodies in preference to ab3 of ancestral (9-40) antigenic specificity, 2) relative to ab1, induce a 100-fold increase in the level of ab3 antibodies that have both ancestral idiotype and ancestral antigen reactivity, and 3) induce polyclonal ab3 antibodies with a measurably wider range of antigenic reactivities than those of polyclonal ab1. These quantitative data may reflect the natural state of an immune network in a diverse antigenic response.
Unique intermolecular bactericidal epitope involving the homosialopolysaccharide capsule on the cell surface of group B Neisseria meningitidis and Escherichia coli K1.
Authors: Jennings H J , Gamian A , Michon F , Ashton F E
Published: December 2022

The N-propionylated group B meningococcal polysaccharide mimics a unique bactericidal epitope on the surface of group B meningococci and Escherichia coli K1. This was confirmed when both the above organisms were able to absorb the bactericidal antibodies from a mouse-anti-N-propionylated group B meningococcal polysaccharide-tetanus toxoid conjugate serum. By using affinity columns it was possible to divide the conjugate antiserum into three distinct populations of both group B polysaccharide cross-reactive and non-cross-reactive antibodies, one of which contained most of the bactericidal activity. The cross-reactive (IgG1) antibodies were absorbed by an affinity column in which the group B polysaccharide was linked to the solid support by a long spacer arm, thereby isolating a population of non-cross-reactive (IgG1) antibodies. Surprisingly the above column also retained another population of non-cross-reactive (IgG2a) and (IgG2b) antibodies which contained most of the bactericidal activity. These latter antibodies were not absorbed by a similar group B polysaccharide-affinity column in which a short spacer arm was employed. Thus the above experiments not only effected a separation of highly bactericidal antibodies but also provided evidence that the long spacer arm is functional in the binding of the bactericidal antibodies to the affinity column. This indicates that the bactericidal epitope is mimicked by the group B polysaccharide in the presence of the long spacer arm, which supports the hypothesis that the epitope is polysaccharide-associated and is probably intermolecular in nature.
Introduction of T cell receptor (TCR)-alpha cDNA has differential effects on TCR-gamma delta/CD3 expression by PEER and Lyon-1 cells.
Authors: De Waal Malefyt R , Alarcon B , Yssel H , Sancho J , Miyajima A , Terhorst C P , Spits H , De Vries J E
Published: December 2022

A TCR heterodimer composed of a TCR gamma-chain and a TCR delta-chain was found to be expressed in association with CD3 by a small population of human peripheral blood T cells, thymocytes, and certain leukemic T cell lines. The leukemic T cell lines PEER and Lyon-1 express such a TCR-gamma delta/CD3 complex at the cell surface. In addition, PEER and Lyon-1 cells transcribe a productively rearranged TCR-beta gene. Introduction of TCR alpha-chain cDNA of human or murine origin resulted in cell surface expression of a TCR-alpha beta/CD3 complex on PEER and Lyon-1 cells. The expression of the TCR-gamma delta/CD3 complex on PEER cells was not affected by introduction of TCR-alpha cDNA. In contrast, introduction of a TCR-alpha cDNA and expression of the TCR-alpha beta/CD3 complex in Lyon-1 cells resulted in the disappearance of the TCR-gamma delta/CD3 complex. These data were confirmed by indirect immunofluorescence, at the protein level and by gene expression analysis. Triggering of the TCR-alpha beta/CD3 complexes by anti-CD3 mAb or anti-TCR mAb resulted in increased internal Ca2+ levels, indicating that these receptors were functional in signal transduction. These results indicate that, besides TCR gene rearrangements, membrane expression of TCR-alpha beta heterodimers may be important in regulating TCR-gamma delta cell surface expression.
Mixed IgA-IgG aggregates as a model of immune complexes in IgA nephropathy.
Authors: Waldo F B , Cochran A M
Published: December 2022

Patients with IgA nephropathy have circulating immune complexes containing IgA, IgG, and C3. We have mixed human IgG and IgA1 and heated them to form mixed aggregate. On sucrose density gradients IgG aggregates were 11 to 19S whereas IgA aggregates were either 11S or greater than 19S. Mixed aggregates had both an 19 and 11 S peak. The isoelectric point of aggregates with only IgG was 7 to 9 and of only IgA 4.5 to 5.5. The isoelectric point of mixed aggregates decreased as the percent IgA increased. IgG aggregates mixed with normal human serum caused 30% C3 activation (20 min, 37 degrees C) whereas IgA aggregates causes no activation. There was a linear decrease in C3 activation as the percent IgA increased. Mixed aggregates that contained either radiolabeled IgG or IgA were mixed with normal human serum (1 h, 37 degrees C) and then solubilized, reduced, and separated by 10% SDS-PAGE. Heavy m.w. bands, consistent with covalent bonding of C3b and C3bi to Ig H chain were only seen in lanes with labeled IgG. This was confirmed by Western blot analysis. A human dimeric IgA1 myeloma protein with rheumatoid factor activity was also studied. It caused 15% alternative pathway C3 activation but did not fix C3 to its H chain. Binding of aggregates (+/- C3) to E was tested. Aggregates with IgG C3 bound but IgA (+/- C3) did not. Addition of greater than 10% IgA to an IgG-C3 aggregate inhibited E binding. We conclude that IgG in mixed aggregates is the site of C3 fixation. In contrast, IgA does not fix C3 but instead lowers the isoelectric point, increases the size and inhibits binding to E. These properties would inhibit clearance and promote mesangial deposition and local C activation.
Generation and characterization of hamster monoclonal antibodies that neutralize murine tumor necrosis factors.
Authors: Sheehan K C , Ruddle N H , Schreiber R D
Published: December 2022

mAb to murine TNF (MuTNF) were produced after immunization of Armenian hamsters with purified, Escherichia coli-derived rMuTNF-alpha. Antibody produced from clone TN3-19.12, was purified and was found to inhibit 100% of the lytic activity of either recombinant or natural MuTNF-alpha at an antibody input of 25 ng/U. TN3-19.12 also inhibited all the lytic activity in culture supernatants from a variety of T cell sources, including activated T cell clones and T cell hybridomas (all of which expressed high levels of TNF-alpha and TNF-beta (lymphotoxin, LT) mRNA). Western blot analysis was used to document the physical form(s) of MuTNF recognized by TN3-19.12. Recombinant and macrophage-derived TNF displayed identical patterns of a single band with Mr 17 kDa. In contrast, T cell culture supernatants exhibited patterns consisting of two bands with Mr 17 and 24.7 kDa. The higher m.w. form was glycosylated based on its sensitivity to n-glycanase and displayed a m.w. consistent with that of TNF-beta (LT). These data suggest that TN3-19.12 recognizes both MuTNF-alpha and MuTNF-beta (LT). Monoclonal TN3-19.12 and polyvalent rabbit anti-rTNF were used to establish a MuTNF-specific ELISA capable of detecting picogram quantities of recombinant or natural TNF. This assay was used to detect TNF in the sera of mice challenged with a lethal dose of LPS. Peak TNF serum levels of 11 ng/ml were observed in these animals 90 min after i.p. LPS administration and then rapidly declined to near base line levels by 3 h. These values were confirmed by quantitating levels of TNF functional activity in the same samples. TN3-19.12 injected into mice subsequently treated with LPS prevented the detection of TNF in the circulation by either assay and protected mice from the lethal effects of endotoxin shock. Thus, TN3-19.12 effectively neutralizes endogenously produced TNF in vivo.
Carbohydrates on human Fc gamma receptors. Interdependence of the classical IgG and nonclassical lectin-binding sites on human Fc gamma RIII expressed on neutrophils.
Authors: Kimberly R P , Tappe N J , Merriam L T , Redecha P B , Edberg J C , Schwartzman S , Valinsky J E
Published: December 2022

To explore the molecular basis for the ability of aggregated IgG to block the phagocytosis by human polymorphonuclear leukocytes of Con A-opsonized E and of nonopsonized Escherichia coli with mannose-binding adhesins, we examined specific aspects of the glycoprotein structure of both the 40- to 43-kDa receptor for the Fc portion of IgG (Fc gamma RII) and the 50- to 78-kDa receptor for the Fc portion of IgG (Fc gamma RIIIPMN) from human polymorphonuclear leukocytes. Fc gamma RIIIPMN isolated by both mAb and ligand affinity chromatography, but not Fc gamma RII, binds Con A in Western blots. This binding is specifically inhibitable by alpha-methylmannoside. Digestion of Fc gamma RIIIPMN by recombinant endoglycosidase H, which is specific for high mannose-type (Con A-binding) oligosaccharides, alters the epitope recognized by mAb 3G8 in or near the IgG ligand-binding site of the receptor. Similarly, the ability of Fc gamma RIIIPMN to bind human IgG ligand is sensitive to endoglycosidase H digestion. Our data indicate that ligands other than the classical IgG opsonins can bind to human Fc gamma RIIIPMN per se through lectin-carbohydrate interactions. Furthermore, Fc gamma RIIIPMN contains a high mannose type oligosaccharide chain which contributes importantly to the integrity of the classical IgG ligand-binding site. Thus, specific glycosylations of the receptor are important for both classical and nonclassical engagement of Fc gamma RIII and may play a role in determining the properties of the ligand-binding site.
Diversity and diversification of HLA-A,B,C alleles.
Authors: Parham P , Lawlor D A , Lomen C E , Ennis P D
Published: December 2022

The nucleotide sequences encoding 14 HLA-A,B,C and 5 ChLA-A,B,C molecules have been determined. Combining these sequences with published data has enabled the polymorphism in 40 HLA-A,B,C and 9 ChLA-A,B,C alleles to be analyzed. Diversity is generated through assortment of point mutations by recombinational mechanisms including gene and allelic conversions. The distribution and frequency of silent and replacement substitutions indicate that there has been positive selection for allelic diversity in the 5' part of the gene (exons 1 to 3) and for allelic homogenization and locus specificity in the 3' part of the gene (exons 4 to 8). These differences may correlate with the lengths of converted sequences in the two parts of the gene and frequency of the CpG dinucleotide. Locus-specific divergence of HLA-A,B, and C demonstrates that recombinational events involving alleles of a locus have been more important than conversion between loci. This contrasts with the predominance of gene conversion events in the evolution of mutants of the H-2Kb gene. However, a striking example of gene conversion involving HLA-B and C alleles of an oriental haplotype has been found. Comparison of human and chimpanzee alleles reveals extensive sharing of polymorphisms, confirming that diversification is a slow process, and that much of contemporary polymorphism originated in ancestral primate species before the emergence of Homo sapiens. There is less polymorphism at the HLA-A locus compared to HLA-B, with greater similarity also being seen between HLA-A and ChLA-A alleles than between HLA-B and ChLA-B alleles. Although greater diversity is seen in the 5' "variable" exons of HLA-B compared to HLA-A, there is increased heterogeneity in the 3' "conserved" exons of HLA-A compared to HLA-B.
Human endothelial cells prolong eosinophil survival. Regulation by cytokines and glucocorticoids.
Authors: Lamas A M , Marcotte G V , Schleimer R P
Published: December 2022

Many recent studies have established the eosinophil as an active proinflammatory participant in a variety of disease states, most notably in allergic and helminthic disorders. In order to understand the effector role of eosinophils, factors which promote a selective eosinophilic infiltrate must be delineated. Eosinophil adherence to vascular endothelium is the first step in the formation of such an infiltrate. However, studies thus far have failed to identify factors which selectively activate the adherence of eosinophils. We have therefore speculated that the selective enrichment of eosinophils may result from nonselective recruitment of several leukocyte types combined with the production of local factors that promote the survival of eosinophils and not of other cells. We report that endothelial cell-conditioned medium selectively prolongs eosinophil survival up to 6 days in culture in a dose- and time-dependent manner. Stimulation of human vascular endothelial cells with IL-1 caused an increase in the generation of eosinophil survival-promoting activity, whereas stimulation with platelet-activating factor did not. Supernatants from human vascular endothelial cells cultured for 48 h in the presence of the glucocorticoid, dexamethasone, were less active in promoting eosinophil survival than control supernatants. These results suggest that factors produced locally in the vascular microenvironment may selectively promote eosinophil survival and may be under the regulation of cytokines and glucocorticoids.
Indiscriminate representation of VH-gene families in the murine B lymphocyte responses to Trypanosoma cruzi.
Authors: Minoprio P , Andrade L , Lembezat M P , Ozaki L S , Coutinho A
Published: December 2022

The utilization of the nine major homology families of VH-genes was quantitated in the B lymphocyte response to Trypanosoma cruzi infection of C57BL/6 mice. Normal and infected mice at various times after parasite inoculation were compared for VH-gene distribution of CFU-B produced by activated blasts recovered from spleen and lymph nodes, and for relative hybridization of total spleen RNA with each of the family probes. T. cruzi infection results in large increases of splenic RNA in the various homology families, and the numbers of activated CFU-B, reflecting the massive B lymphocyte responses. In acute phase, all nine families are expressed in roughly the same proportions as in normal mice, whereas in chronic infection, B cells expressing S107 and 7183 VH-genes might be preferentially stimulated. These results establish the polyclonal nature of the host response to T. cruzi infection.
Differential expression of the class I MHC genes in the embryo and placenta during midgestational development in the mouse.
Authors: Hedley M L , Drake B L , Head J R , Tucker P W , Forman J
Published: December 2022

A sensitive RNase mapping technique was used to investigate the expression of individual class I mRNA in the embryo and placenta of the mouse from day 7.5 through day 13 of gestation. Transcripts of the H-2Kd and -Dd genes appeared in both placental and embryonic tissues as early as day 7.5 post coitum and continued to be expressed thereafter. In contrast, H-2Ld mRNA was barely detectable in embryonic RNA until day 18 of pregnancy, although it was present in placental RNA samples on days 10 to 13 of gestation. Qa-region genes demonstrated a different pattern of expression than H-2Dd, -Kd, and -Ld. Transcripts of Q7, one of the genes encoding Qa-2 surface Ag, were detected in the developing embryo on days 9 to 11 post coitum but decreased thereafter. However, Q7d transcripts were not detected in placental tissues at any stage. Q6 mRNA was not detected in any of the tissues, and Q10 mRNA was detected only in day 12 to 13 embryos, where expression is known to be restricted to the fetal liver. Transcripts from T13, a Tla-region gene, and D2d, a D-region gene, were not detected in any of the samples tested. This study has revealed a complex pattern of class I gene regulation both within the genes of the MHC and between the embryo and placental lineages during the midgestational stages of development.
Stimulation of mouse lymphocytes by a mitogen derived from Mycoplasma arthritidis. VII. Responsiveness is associated with expression of a product(s) of the V beta 8 gene family present on the T cell receptor alpha/beta for antigen.
Authors: Cole B C , Kartchner D R , Wells D J
Published: December 2022

Mycoplasma arthritidis produces a potent soluble T lymphocyte mitogen (MAM) which is dependent upon accessory cells bearing the alpha-chain of the I-E molecule (E alpha). Lymphocytes from the RIIIS mouse strain which possess E alpha yet whose T cells fail to recognize the MAM-E alpha complex were shown not to express V beta 8.1, 8.2 or 8.3 gene products present on the TCR-alpha/beta by virtue of their lack of reactivity with the F23.1 mAb. Because lymphocytes from the congenic B10.RIII mouse strain reacted positively with F23.1, we examined the progeny from (RIIIS x B10.RIII)F1 x RIIIS backcross mice for cosegregation of lymphocytes expressing F23.1-reactive sites and ability to proliferate in response to MAM. Whereas lymphocytes of all mice responded to Con A, only lymphocytes from progeny expressing F23.1-reactive cells responded to MAM. Similar studies were conducted on progeny from the F23.1- SWR mouse which was backcrossed to (SWR x B10.RIII)F1 mice. Of the E alpha-bearing progeny, there was a direct correlation between lymphocyte expression of F23.1 determinants and ability to respond to MAM. These results established that MAM reactivity was dependent upon a product(s) of the V beta locus of the TCR-alpha/beta. Nodal and thymic lymphocytes cultured for 3 days in vitro with MAM exhibited clonal expansion of F23.1 and F23.2-reactive cells as compared with cultures treated with Con A. We also demonstrated that F23.1 and F23.2 mAb inhibited the ability of lymphocytes to proliferate in response to MAM but had little effect on responses to Con A. The combined data suggest that the MAM-E alpha complex can utilize a V beta 8 gene product(s) on the TCR-alpha/beta.
Molecular interactions required for triggering alloantigen-specific cytolytic T lymphocytes.
Authors: Kane K P , Sherman L A , Mescher M F
Published: December 2022

Affinity-purified class I proteins in detergent solution can be directly immobilized on plastic by a simple dilution procedure. The immobilized Ag retains its native structure and will trigger specific, TCR-mediated degranulation of cloned CTL. Stimulation of the response is dependent on the surface density of Ag, and displays a critical threshold density below which response does not occur. Individual clones differ with respect to the threshold density required for activation, but these differences are not large. With one exception, the cloned lines examined respond to Ag densities comparable to that found on normal allogeneic cells, and critical threshold densities varied over about a fourfold range. Coimmobilization of alloantigen and nonantigenic class I protein of a different specificity has the effect of decreasing the threshold density of alloantigen required for response to occur. This augmentation is specific for class I, coimmobilized class II protein does not affect responses, and is very likely mediated by Lyt-2 (CD8) interaction with nonpolymorphic determinants on the class I protein. Thus, class I alloantigen is the necessary and sufficient ligand for activation of most allogeneic CTL clones, and both TCR and Lyt-2 interactions contribute to the response. The results described here for effector CTL are compared with those previously found in examining the ligand requirements for activation of precursor CTL.
Processing and presentation of insulin. II. Evidence for intracellular, plasma membrane-associated and extracellular degradation of human insulin by antigen-presenting B cells.
Authors: Semple J W , Ellis J , Delovitch T L
Published: December 2022

To study the biochemistry of processing of a soluble protein Ag by an APC, we investigated how 125I-labeled human insulin (HI) is processed in situ by TA3 mouse hybridoma B cells. Fractionation of TA3 cells into their extracellular, plasma membrane-associated and intracellular compartments coupled with the use of HPLC enabled us to analyze several peptides derived from each compartment. One HI peptide found in all three compartments is composed of residues A1-A14 disulfide-linked to B7-B26 (A1-A14/B7-B26). The presence of this peptide in the extracellular compartment likely resulted from digestion of HI by an enzyme(s) released from the APC. Extracellular processing of radiolabeled HI was inhibited completely by unlabeled HI and N-ethylmaleimide, an inhibitor of a previously described insulin-specific protease, partially by lysozyme but not by BSA or OVA. This suggests that the enzyme involved in the extracellular processing of insulin is relatively insulin-specific and gives rise to the A1-A14/B7-B26 peptide. The processing of HI both at the plasma membrane and intracellularly was inhibited by chloroquine, monensin, and NH4Cl, suggesting that both intracellular pH changes and endocytic and exocytic events may be required for these compartments to process insulin. Kinetic analyses revealed that the processing of insulin into the A1-A14/B7-B26 peptide is first detected at the plasma membrane then intracellularly and finally in the extracellular compartment. This unlabeled A1-A14/B7-B26 peptide was purified from the extracellular compartment of TA3 APC by HPLC; when presented by TA3 APC this peptide effectively stimulated pork insulin (PI/I-Ad) specific Th cells to secrete IL-2. These data, taken together with the identification of another processed insulin peptide, A7-A11/B7-B26, have enabled us to elucidate the first steps in the biochemical pathway(s) of processing of insulin as an Ag in a B cell APC.
Soluble IL-2 receptor in AIDS. Correlation of its serum level with the classification of HIV-induced diseases and its characterization.
Authors: Honda M , Kitamura K , Matsuda K , Yokota Y , Yamamoto N , Mitsuyasu R , Chermann J C , Tokunaga T
Published: December 2022

By using a fluorescence sandwich ELISA, elevated IL-2R levels were detected in the sera from both HIV-infected hemophiliacs and other HIV-infected patients. The serum IL-2R levels were reflective of the classification of HIV-induced diseases by the Centers for Disease Control. Moreover, the IL-2R levels were negatively correlated most prominently with CD4 cell counts, with lymphocyte counts, and with a decrease in the CD4-CD8 ratio but not with either WBC counts or B cell counts. As striking elevations of serum IL-2R were noted in AIDS patients with group IVD infection, the serum IL-2R was purified sequentially by using size-exclusion HPLC, high-pressure chromatofocusing, and H48 affinity HPLC. The isoelectric point values of IL-2R were separated into 4.2 and 3.8, whereas the Mr was determined to be only 45 kDa by immunoprecipitation with H48 antibody followed by SDS-PAGE. However, production of cellular and supernatant IL-2R was not elevated in PBMC of patients with AIDS or in any of the 19 HIV-I- or HIV-II-infected cell line cells. In contrast, PBMC from patients with adult T cell leukemia and cell line cells that expressed human T cell lymphotropic virus -I or -II produced soluble IL-2R, constitutively. The mechanisms by which serum levels of IL-2R might be elevated in HIV-infected patients are discussed in comparison with that in adult T cell leukemia patients.
HLA class I-related impairment in IL-2 production and lymphocyte response to microbial antigens in reactive arthritis.
Authors: Inman R D , Chiu B , Johnston M E , Vas S , Falk J
Published: December 2022

The contribution of certain Gram-negative bacteria and host HLA class I Ag to the development of reactive arthritis (ReA)3 has strong epidemiologic support but the pathogenesis of the arthritis is unknown. An outbreak of Salmonella typhimurium afforded the opportunity to compare the immune response to the organism between those who developed ReA (ReA+, n = 11) with those who did not (ReA-, n = 12). Of the 11 ReA+ patients, 4 were B27-positive and 6 were B7-positive; of the ReA- patients none was B27- or B7-positive. The causative pathogen S. typhimurium phage 22 was used to examine PBL proliferation by [3H]thymidine incorporation. Impairment in lymphocyte response to S. typhimurium in ReA+ compared with ReA- was demonstrated by: i) lower stimulation index (1.9 +/- 0.3 for ReA+, 5.7 +/- 0.6 for ReA-, p less than 0.01); ii) lower in vitro Ig production; and iii) lower Ag-induced IL-2 production. Mixing experiments did not demonstrate a soluble suppressor factor in ReA+ supernatants. Thus, after infection with S. typhimurium there is an impairment in cellular immunity that has correlates in immunogenetic and clinical features of the infected population.
Synthetic peptide corresponding to a conserved domain of the retroviral protein p15E blocks IL-1-mediated signal transduction.
Authors: Gottlieb R A , Lennarz W J , Knowles R D , Cianciolo G J , Dinarello C A , Lachman L B , Kleinerman E S
Published: December 2022

We studied the mode of action of the synthetic peptide CKS-17, which is a heptadecapeptide homologous to a highly conserved region of the immunosuppressive retroviral envelope protein p15E, as well as to envelope proteins of the human T cell leukemia virus I and II. Previous studies have established that CKS-17 conjugated to BSA (CKS-17-BSA) inhibited IL-1-mediated tumor toxicity in melanoma cells and proliferation in murine Th clones. We examined the effects of CKS-17-BSA on IL-1 action. CKS-17-BSA did not bind to IL-1, nor did it affect the number of IL-1 receptors, their binding affinity, or their ability to internalize IL-1. However, CKS-17-BSA inhibited production of IL-2 by murine thymoma cells treated with IL-1 or with 12-O-tetradecanoyl phorbol-13 acetate. The potent protein kinase C inhibitor, H7, also inhibited IL-1-mediated responses, while HA1004, a weak inhibitor of protein kinase C, did not. Protein kinase C activity in the cytosolic fraction prepared from thymoma cells was found to be inhibited by CKS-17-BSA in a dose-dependent manner. All of these findings are consistent with the idea that CKS-17-BSA inhibits IL-1-mediated responses by interfering with signal transduction through a protein kinase C pathway.
Molecular and serologic analysis of IgG1 deficiency caused by new forms of the constant region of the Ig H chain gene deletions.
Authors: Smith C I , Hammarström L , Henter J I , de Lange G G
Published: December 2022

Selective IgG1 deficiency is a rare disease. We report a familial form of IgG1 deficiency, in which IgG1 was undetectable in a 5-yr-old girl with a history of asthma and respiratory tract infections. Her father had an IgG1 level that was one-third of the mean amount found in normal healthy controls. The defect in the proband was caused by a homozygous deletion of the structural gene for C gamma 1. A Southern blot analysis demonstrated that the maternal haplotype contained a deletion encompassing C gamma 1, C psi epsilon 1, C alpha 1, C psi gamma, and C gamma 2, whereas the deletion on the paternal haplotype was confined to the C gamma 1 gene. Neither of these deletions has previously been reported. IgG1 normally constitutes the dominant isotype for antibodies directed against protein Ag, including viral proteins. We have analyzed the immune response to a number of different protein and polysaccharide Ag in the patient and her parents. In the proband, antiviral antibodies were restricted to the IgG3 and IgG4 subclasses. However, the total amount of IgG directed against several viruses was below the concentration found in normal seropositive individuals. The father and the paternal grandfather, both with low serum IgG1 levels, also had asthma, thus indicating a possible causal relationship.
Evidence against the existence of a membrane form of murine IL-1 alpha.
Authors: Minnich-Carruth L L , Suttles J , Mizel S B
Published: December 2022

Previous studies have demonstrated that paraformaldehyde-treated macrophages possess IL-1 alpha activity in a variety of bioassay systems. However, no definitive biochemical data in support of the membrane IL-1 alpha concept has been reported. The purpose of the present study was to determine if the biologic activity associated with treated cells is due to a membrane form of IL-1 alpha or alternatively, to the leakage of IL-1 alpha. If the former case was true, then the exposed membrane IL-1 alpha should bind anti-IL-1 alpha antibodies or be cleaved by mild trypsin treatment. In both instances, IL-1 alpha activity should be lost when measured in a subsequent IL-1 bioassay. Our results indicate that pulsing paraformaldehyde-treated normal or cell line macrophages with anti-IL-1 alpha antibodies or treating the cells with trypsin did not affect the ability of the treated cells to function in a murine thymocyte proliferation assay. Furthermore, the standard short term treatment of cells with paraformaldehyde (15 min) did not prevent the leakage of IL-1 alpha from the cells or the processing of the precursor forms of the protein. When cells were treated with paraformaldehyde for 2 h, they no longer released IL-1 alpha or possessed thymocyte stimulatory activity. We also found that short term glutaraldehyde treatment of macrophages completely blocked the release of IL-1 alpha from cells as well as the appearance of cell-associated IL-1 alpha activity. Our results support the conclusion that the stimulatory activity of paraformaldehyde-treated macrophages is not due to a membrane form of IL-1 alpha but is, in fact, due to the continuous release of IL-1 alpha from the cells.
T lymphocyte cytotoxicity with natural varicella-zoster virus infection and after immunization with live attenuated varicella vaccine.
Authors: Diaz P S , Smith S , Hunter E , Arvin A M
Published: December 2022

Varicella-zoster virus (VZV) specific cytotoxicity was investigated during acute primary VZV infection, in naturally immune subjects and after vaccination with the live attenuated varicella vaccine by using T cell cultures (TCC) generated by stimulating PBMC with VZV Ag and autologous VZV-superinfected lymphoblastoid cell lines as targets. Lysis of VZV-infected lymphoblastoid cell lines was observed by TCC from acutely infected subjects, naturally immune subjects, and recipients of the varicella vaccine. VZV glycoprotein I induced cytotoxic T cells but killing was less efficient than killing by TCC stimulated with VZV Ag. The TCC were primarily CD4+ (mean 86.6%) T lymphocytes with 15.2% of the cells coexpressing Leu-19. TCC were predominantly restricted by HLA class II as demonstrated by lack of any blocking using class I mAb and blocking of 15 to 71% by L243, a mAb to class II. Unrestricted killing as measured by killing of K562 cells occurred in all TCC but was minimally greater than that observed against uninfected autologous targets. Phenotypes of PBMC during acute infection had an initial increase in CD4+ cells and an overall decrease in the percentage of circulating Leu-11+ (CD16). No enhanced K562 killing was demonstrated in PBMC from subjects with acute infection compared to subjects without infection. CD4+ CTL may function as an important primary host response in acute varicella. Immunization with live attenuated varicella vaccine induced VZV-specific, memory CTL responses comparable to those of naturally immune subjects. The demonstration of their persistence long after primary VZV infection may indicate a role for CTL in restriction of viral replication during episodes of VZV reactivation from latency.
Polyamine oxidation down-regulates IL-2 production by human peripheral blood mononuclear cells.
Authors: Flescher E , Bowlin T L , Talal N
Published: December 2022

Polyamine biosynthesis by mononuclear cells (MNC) appears to regulate T cell activity since 1) inhibition of polyamine biosynthesis increases IL-2 production and 2) H2O2 (a product of polyamine oxidase, PAO), suppresses lymphocyte proliferation. We investigated this immunoregulatory mechanism and find that catalase, an H2O2 inhibitor, also enhances IL-2 production by MNC. The addition of PAO, but only in the presence of either endogenous or exogenous spermidine (a polyamine), decreases IL-2 production; this effect is catalase inhibitable. Pre-incubation with spermidine, but not any of three diamines tested, suppresses PHA-stimulated IL-2 production and this effect requires monocytes. Three PAO inhibitors have an enhancing effect on IL-2 production which is again monocyte dependent. These results suggest that: 1) H2O2 produced by PHA-activated PBMC down-regulates IL-2 production; 2) products of the interaction between PAO and spermidine inhibit IL-2 production and H2O2 is essential but apparently not sufficient to mediate this effect; 3) human PBMC contain PAO activity. This polyamine-PAO-dependent inhibitory mechanism might constitute a feedback loop that limits human T cell proliferation and, consequently, also the immune responses mediated by these cells.
Toxoplasma gondii: mechanism of resistance to complement-mediated killing.
Authors: Fuhrman S A , Joiner K A
Published: December 2022

Tachyzoites of the obligate intracellular protozoan Toxoplasma gondii are resistant to lysis in non-immune human serum. We have examined the mechanism of this serum resistance in RH and P strain organisms, which differ markedly in virulence, but are equally resistant to serum killing. Rapid, but limited, activation of the alternative complement pathway occurred in non-immune human serum, with deposition of equivalent amounts of C3 on the two strains. C component C3 bound covalently to parasite acceptor molecules via an ester linkage. The predominant form of C3 was iC3b which cannot participate in formation of a lytic C5b-9 complex. Multiple membrane constituents of the tachyzoite of T. gondii may serve as acceptors for the limited amount of C3 deposited during incubation in non-immune serum. When tachyzoites were presensitized with the lytic anti-p30 mAb 7B8, new amide-linked C3-acceptor complexes formed. Nearly equivalent C3 binding but a threefold enhancement of 125I-C9 binding occurred when mAb 7B8 pre-sensitized tachyzoites were compared to native organisms. These results indicate that tachyzoites of T. gondii are serum resistant because of failure to activate C efficiently. Presensitization with a lytic mAb alters the site of complement deposition and augments C5b-9 formation.
The effect of lipopolysaccharide desensitization on the regulation of in vivo induction of immunologic tolerance and antibody production and in vitro release of IL-1.
Authors: Weigle W O , Gahring L C , Romball C G , Goodman M G
Published: December 2022

As previously reported, LPS and 8-derivatized guanosine (both generators of IL-1 release), as well as IL-1 itself interfere with the in vivo induction of tolerance to DHGG in A/J mice. In the present studies it was demonstrated that desensitization of either A/J or CBA/CaJ mice with LPS aborts the ability of LPS to interfere with the induction of tolerance to DHGG. The abrogation of the ability of LPS to interfere with tolerance by LPS desensitization is not the result of neutralization of LPS by antibody produced to LPS during desensitization. Desensitization with LPS also aborts the interference with tolerance induction by 7-methyl-8-oxoguanosine. LPS desensitization inhibits the ability of LPS and/or 7-methyl-8-oxoguanosine to both convert a tolerogenic signal to an immunogenic signal and interfere with the induction of a tolerant state to a subsequent injection of Ag. The effects resulting from desensitization may be in part attributed to the depletion of IL-1. LPS desensitization also modulates the antibody response to injection of the AG, AHGG. Desensitization with LPS markedly suppresses the antibody response to a subsequent injection of AHGG in CBA/CaJ mice. Desensitization with LPS also inhibits the anti-HGG antibody response in A/J mice, but in this strain its effect is dependent on the route of injection of AHGG. In an experiment directly comparing the responses of normal and desensitized A/J mice to either intravenous or intraperitoneal injection of AHGG, desensitization only suppressed the response in mice injected with AHGG i.p.. Desensitization with LPS also inhibits the ability of LPS to act as an adjuvant in a subsequent antibody response to AHGG. Not only does desensitization interfere with the primary antibody response to AHGG, but it also interferes with the secondary response, suggesting that the primary injection after desensitization induces a state of immunologic tolerance.