bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunity to herpes simplex virus type 2: viral antigen-presenting capacity of epidermal cells and its impairment by ultraviolet irradiation.
Authors: Hayashi Y , Aurelian L
Published: December 2022

Ia+ epidermal cells (EC) had accessory cell function for herpes simplex virus type 2 (HSV-2)-induced T cell proliferation of immune lymph node cells (LNC). The EC-mediated virus-induced proliferative response of immune LNC was inhibited by ultraviolet B (UVB) irradiation. When EC were pulsed with viral antigen before UVB irradiation, the response was partially restored by addition of epidermal cell-derived thymocyte-activating factor (ETAF). Although normal EC secreted prostaglandin E2, the levels secreted by UVB-irradiated EC were significantly reduced, and the UVB-induced suppression of the proliferative response of immune LNC was not corrected by indomethacin. Soluble factor(s) that suppresses proliferation was generated in supernatants from cultures containing UVB-irradiated but not nonirradiated EC. Sephadex chromatography revealed the presence of factors differentially modulating the proliferative response of HSV-stimulated immune LNC and concanavalin A-stimulated normal lymphoid cells.
The rabbit kappa 1 b5 immunoglobulin gene: another J region gene cluster with only one functional J gene segment?
Authors: Esworthy S , Max E E
Published: December 2022

Our previous analysis of an immunoglobulin gene encoding the rabbit kappa chain of b4 allotype revealed that of the five J-like sequences in the J kappa cluster of this gene, only one, J2, appeared to be functional. This unusual ratio of J pseudogenes to functional J genes is unique among all J clusters of light and heavy chain genes of all species examined to date, including the cluster from the rabbit kappa 2 isotype, and must have consequences for diversity generation of b4 immunoglobulins. The fact that the only two known b5 J kappa sequences are different from the functional J2 of the b4 allotype prompted investigation of the b5 J kappa cluster to determine whether it resembled the b4 cluster, or the more typical mouse or human J kappa clusters. Our analysis of the b5 gene reveals a J kappa cluster strikingly similar to that of b4; apparent defects occur in all J sequences except J2. Although J2 is apparently functional, it differs from the J2 of the b4 locus by four nucleotide and three amino acid substitutions. The unusually high degree of sequence similarity previously observed between the b4 and b5 loci in the noncoding (vs the coding) regions extends through the newly sequenced DNA segment and remains an enigma.
DNA of human Raji target cells is damaged upon lymphocyte-mediated lysis.
Authors: Gromkowski S H , Brown T C , Cerutti P A , Cerottini J C
Published: December 2022

Human Raji target cells DNA is degraded by the introduction of single-strand breaks (alkali-sensitive sites) upon lymphocyte-mediated lysis. This type of DNA degradation appears earlier and is more extensive in lymphocyte-than in antibody + complement-mediated lysis of Raji cells, regardless of the species of effector lymphocytes (human or mouse). Mouse P815 target cell DNA is extensively fragmented (yielding 200 base pair fragments) when human or mouse lymphocytes are used to lyse P815. Thus, these observations indicate that both human and mouse target cell DNA are affected during lymphocyte-mediated lysis. Moreover, the pattern of DNA degradation in target cells lysed by effector lymphocytes is characteristic of the target cell species, suggesting that DNA degradation proceeds through the activation of target cell endonuclease(s).
Functional analysis of the interaction of the antigen-specific T cell receptor with its ligands.
Authors: Ashwell J D , Fox B S , Schwartz R H
Published: December 2022

Increasing the number of antigen-specific T cell clones in a T cell proliferation assay resulted in a shift in the antigen dose-response curves toward higher amounts of antigen (i.e., more antigen was required to achieve a given degree of stimulation). The antigen dose-response curve shifts were found to reflect the competition that occurred between the antigen-specific T cell receptors for their ligand, a combination of antigen and Ia molecule. This observation made it possible to determine whether the difference in the potency with which several synthetic cytochrome c analogs could stimulate one cytochrome c-specific T cell clone was due to a difference in the avidity of the antigen-specific receptors on the T cell clone for the different Ia molecule-antigen combinations. It was demonstrated that a single amino acid substitution at position 103 (which greatly diminished the potency of the analog) did not significantly alter the avidity of the T cell antigen-specific receptor for its ligand. In contrast, a substitution at position 99 (which resulted in a comparable decrease in potency) caused a dramatic loss of avidity. These results are consistent with the previous designation of residue 99 as one site on the antigen that contacts the T cell antigen-specific receptor, and of residue 103 as one part of the antigen that contacts the Ia molecule.
Regulation of B cell tolerance by macrophage-derived mediators: antagonistic effects of prostaglandin E2 and interleukin 1.
Authors: Goldings E A
Published: December 2022

A role for prostaglandins in the mechanism of B cell tolerance induction in normal adult mouse spleen cells was examined. Two inhibitors of the cyclooxygenase pathway of arachidonic acid metabolism, indomethacin and acetylsalicylic acid, abrogated hapten-specific B cell tolerance induction by trinitrophenyl-human gamma-globulin. Tolerance was fully restored by the addition of prostaglandin E2 (PGE2) at a concentration of greater than or equal to 6 nM. T cell-depleted spleen cells produced comparable amounts of PGE2 in culture, indicating that the tolerance promoting activity of PGE2 occurred with physiologically relevant concentrations. Depletion and reconstitution experiments indicated that macrophages in the spleen cell preparations completely accounted for both PGE2 production and the effects of indomethacin and acetylsalicylic acid on B cell tolerance induction. The macrophage product interleukin 1 (IL 1) was also found to alter B cell susceptibility to tolerance induction. Thus, human IL 1 containing monocyte supernatants and purified IL 1 were found to interfere with B cell tolerance induction when added to macrophage- and T cell-depleted splenic B cells. Tolerance was restored in such cultures by the addition of 10 nM PGE2. These experiments demonstrate that within mixed lymphoid populations macrophages through the release of mediators modulate B cell susceptibility to tolerance induction.
T cell development in B cell-deficient mice. IV. The role of B cells as antigen-presenting cells in vivo.
Authors: Hayglass K T , Naides S J , Scott C F , Benacerraf B , Sy M S
Published: December 2022

B cell-deficient, rabbit anti-mouse IgM-treated mice were compared with normal or normal rabbit immunoglobulin-treated controls in their ability to develop proliferative T cell responses, delayed hypersensitivity, and primary or secondary cytotoxic T cell responses. Immunization with hapten-coupled autologous spleen cells resulted in anti-mu-treated mice generating only marginal T cell responses. This decreased responsiveness was shown to be attributable not to an intrinsic T cell defect or to changes in the ability of macrophages from anti-mu-treated mice to present soluble antigen, but rather to the greatly diminished capacity of B cell-deficient spleen cells to present antigen. The results support the concept that B cells play a significant role in antigen presentation required for T cell activation.
Subpopulations of neutrophils with increased oxidative product formation in blood of patients with infection.
Authors: Bass D A , Olbrantz P , Szejda P , Seeds M C , McCall C E
Published: December 2022

Stimulated human polymorphonuclear leukocytes (PMNL) have a marked increase in oxidative metabolism, producing reduced oxygen species (e.g., H2O2) that mediate bacterial killing. Previously, quantitation of metabolic responses of PMNL from patients with acute infections employed assays that measure mean activity of the entire PMNL population; such studies reported a modest and highly variable increase in oxidative metabolic responses of such "toxic" PMNL compared with normal cells. To assess metabolic capability of PMNL from 51 patients with acute bacterial infection, we employed a quantitative flow cytometric assay of H2O2-dependent oxidative product formation, the intracellular oxidation of 2',7'-dichlorofluorescin (DCFH). After stimulation by phorbol myristate acetate, the PMNL of patients demonstrated an increase in mean DCFH oxidation (315 +/- 14 and 180 +/- 4.5 amol/cell, patients and controls). Hexose monophosphate shunt activation was similarly increased in stimulated PMNL from bacteremic patients. These data are comparable with previous studies of mean metabolic activities of toxic PMNL. However, these mean values underestimate the quantitative responses of the hyperresponsive ("primed") PMNL within a mixture of normal and primed PMNL in the patients' blood. The flow cytometric assay demonstrated that the PMNL of the patients were composed of two populations. One population of PMNL had normal oxidative responses; the other "primed" population had up to 4.6 times the oxidative product formation of normal cells. Similar priming of circulating PMNL was caused by infection with gram-positive or gram-negative staining bacteria or by Candida species. The proportion and oxidative ability of the primed PMNL occurred independently of the number of juvenile neutrophil forms and independently of "toxic" morphologic changes of Wright's-stained PMNL. On the average, 40% of the PMNL of patients were primed, but the size of the primed PMNL population varied widely between patients (range 0 to 80%). This variable subpopulation may explain the variability of mean responsiveness of the PMNL of patients reported previously. Moreover, the marked increase in oxidative metabolic capability of the primed PMNL may be a significant component of the host response to acute infection. It could also contribute to the damage to host tissues such as pulmonary vascular endothelium during bacteremia.
The human immune response to reconstituted bovine collagen.
Authors: Ellingsworth L R , DeLustro F , Brennan J E , Sawamura S , McPherson J
Published: December 2022

The human immune response to bovine dermal collagen was characterized through histologic, serologic, and immunoblotting methods. Collagen-sensitive patients were identified by hypersensitivity to intradermal exposure to ZYDERM Collagen Implant--a pepsin-solubilized, reconstituted, bovine dermal collagen. Biopsies of test sites in the forearm were obtained from several collagen-sensitive patients. Histologic examination revealed an implant-associated palisading foreign body granuloma. The lesion also contained a mixed cell infiltrate of histiocytes, lymphocytes, and eosinophils. Sera were collected from patients who developed erythema or induration at intradermal test or treatment sites, and were evaluated for antibodies to bovine dermal collagen by an enzyme-linked immunosorbent assay (ELISA). Sera with anti-collagen antibodies were further characterized in this study. The circulating antibodies were reactive with both native and heat-denatured bovine dermal collagen. By using purified alpha 1(I) and alpha 2(I) polypeptides, these sera were found to have antibodies reactive with both alpha-chains. Each alpha-chain was fragmented by using cyanogen bromide (CB). The CB peptides were electrophoretically separated, and these sera were evaluated for antibodies to the major fragments by using an immunoblotting technique. Of the sera evaluated by this method, 89% (23/26) had antibodies to alpha 1-CB6; 77% (20/26) had antibodies to alpha 2-CB4; and 65% (17/26) had antibodies reactive with both CB fragments. In addition, most sera (77%) contained antibodies reactive with two or more (up to five) of the major CB peptides. The least antigenic fragment was alpha 2-CB3,5 (8%). In addition, these sera had antibody activity against both native and heat-denaturated bovine types III and II collagens. Little or no interspecies (rat or guinea pig) cross-reactivity (types I and II) was detected. Furthermore, these sera did not have antibodies against human types I, II, and III collagens.
Stages of T cell activation: continued antigen dependence of IL 2-producing cells after IL 2 receptor expression.
Authors: Miller R A , Rozans M K , Ythier A A , Strom T B
Published: December 2022

Alloantigen stimulation leads, within 48 to 72 hr, to the expression of IL 2 receptors (IL 2R) on the surface of most of the helper T cells with specificity for the stimulating antigens. The IL 2R-bearing cells, separated by flow cytometry from 3-day human or mouse mixed lymphocyte cultures, were found by limiting dilution methods to be enriched 10- to 20-fold (compared to IL 2R- cells) for antigen-specific helper T cells detected by IL 2 production. Although these cells have been activated to an IL 2R+ stage, most of them are unable to produce detectable IL 2 unless they are cultured together with the original, activating antigen. Even when IL 2 is supplied, and lymphokine production measured by assay of a second factor, IL 3, the large majority of individual activated helper T cells remain dependent on further antigenic exposure for their continued maturation into lymphokine-secreting effectors. Helper T cells at this early stage of activation can therefore proliferate when given IL 2 alone, but lymphokine secretion involves a second antigen-dependent step.
Distinction of B cell maturation factors from lymphokines affecting B cell growth and viability.
Authors: Sherris D I , Sidman C L
Published: December 2022

Supernatants from S26.5 helper T cells, autoimmune viable motheaten (mev/mev) mouse spleen cells, EL4 lymphoma cells, and recombinant DNA-derived interferon gamma (IFN-gamma), all of which display B cell maturation factor (BMF) activity, were assayed for effects on B cell proliferation alone and with Dextran Sulfate (DxS) and anti-immunoglobulin antibodies (alpha-Ig). Both EL4 and S26.5 supernatants showed BCGF-II (DxS co-stimulator) activity, whereas only EL4 supernatant had BCGF-I (alpha-Ig co-stimulator or BSF-I) activity. Supernatants from mev/mev spleen cells and recombinant DNA-derived IFN-gamma showed no activity in either assay. Fractionation of S26.5 supernatant by chromatofocusing showed a divergence of BMF activity (BMF-T, pIa of 6.0) from BCGF-II activity (pIa of 5.4), providing evidence for their physical nonidentity. IFN-gamma, which decreases B cell viability in culture, was separable from BMF-T by phenyl-Sepharose chromatography. BMF-T from S26.5 supernatant was separated from IFN-gamma and BCGF-II and was shown to induce B cell maturation without affecting B cell proliferation. The molecular characteristics of the purified BMF-T were pIa 6.0, Mr 55,000 by G-75 gel filtration, and Mr 16,000 by SDS-PAGE. These data demonstrate that several lymphokines (BMF) exist that mediate the maturation of B cells to active Ig secretion without stimulating B cell proliferation.
Activation of the Na+/H+ antiport is not required for lectin-induced proliferation of human T lymphocytes.
Authors: Mills G B , Cheung R K , Cragoe E J , Grinstein S , Gelfand E W
Published: December 2022

Interaction of some mitogenic lectins and growth factors with the cell surface leads to activation of the Na+/H+ antiport and a resultant cytoplasmic alkalinization. Because amiloride inhibits both Na+/H+ exchange and cell proliferation, it has been hypothesized that activation of the antiport is an obligatory requirement and may, perhaps, be the "trigger" for proliferation. However, concentrations of amiloride which inhibit the antiport also inhibit several other intracellular processes, including protein synthesis and phosphorylation. To determine whether activation of the Na+/H+ antiport is necessary for lectin-induced proliferation, we examined the inhibitory activity of a series of potent amiloride analogs by measuring [3H]thymidine incorporation, cell cycle progression, and induction of the interleukin 2 (IL 2) receptor on human lymphocytes. In medium containing bicarbonate, and at concentrations at least 10 times higher than required to inhibit the antiport, these drugs did not inhibit the proliferative response of human peripheral blood T cells to the mitogen phytohemagglutinin. The amiloride analogs also failed to inhibit induction of the IL 2 receptor. Similarly, with human thymocytes, the amiloride analogs did not inhibit the co-mitogenic effects of the lectins phytohemagglutinin and concanavalin A together with IL 2 or the phorbol ester 12-O-tetradecanoylphorbol-13-acetate. This finding suggests that Na+/H+ exchange through the antiport is not an obligatory requirement for activation or proliferation of human lymphocytes or thymocytes.
Induction of alloreactive cytotoxic T cells by acute virus infection of mice.
Authors: Yang H , Welsh R M
Published: December 2022

Alloreactive cytotoxic T lymphocytes (CTL) distinct from virus-specific CTL and activated natural killer (NK) cells were generated during acute lymphocytic choriomeningitis virus (LCMV) infection of C57BL/6J mice. The alloreactive CTL shared similar antigenic markers (Thy-1.2+, Lyt-2.2+, and asialo GM1-) with the virus-specific CTL that appeared at the same time 7 days postinfection, but had different target specificities. These alloreactive CTL lysed allogeneic but not syngeneic or xenogeneic targets. These were distinct from activated NK cells, which lysed all target cell types, peaked 3 days postinfection, and had a phenotype of asialo GM1+, Thy-1 +/-, Lyt-2.2-. Cold target competition studies indicated that there were several subsets of alloreactive T cells with distinct specificities, and that these alloreactive T cells were not subsets of the virus-specific T cells. Similar types of alloreactive CTL were induced at much lower levels in C3H/St mice. This may indicate that the generation of this "aberrant" T cell activity is under genetic control. Hence, the LCMV infection of C57BL/6J mice induces several cytotoxic effector populations including alloreactive CTL, activated NK cells, and virus-specific CTL. Virus infections therefore have the ability not only to polyclonally stimulate B cells, as previously described, but also to stimulate CTL.
Formation of mast cell colonies in methylcellulose by mouse peritoneal cells and differentiation of these cloned cells in both the skin and the gastric mucosa of W/Wv mice: evidence that a common precursor can give rise to both "connective tissue-type" and "mucosal" mast cells.
Authors: Kobayashi T , Nakano T , Nakahata T , Asai H , Yagi Y , Tsuji K , Komiyama A , Akabane T , Kojima S , Kitamura Y
Published: December 2022

We investigated the issue of mast cell heterogeneity by cloning mast cell colonies from peritoneal cells in methylcellulose, injecting the cloned cells into the skin and stomach of mast cell-deficient (WB X C57BL/6)F1-W/Wv (WBB6F1-W/Wv) mice, and staining the mast cells that developed in these sites with Berberine sulfate, a fluorescent dye that identifies heparin-containing mast cells. When peritoneal cells of nontreated WBB6F1-+/+ mice were plated in methylcellulose containing pokeweed mitogen-stimulated spleen cell conditioned medium, pure mast cell colonies developed. In contrast, the peritoneal cavity of genetically mast cell-deficient WBB6F1-W/Wv mice lacked the progenitor cells that made mast-cell colonies. The clonal nature of the mast cell colonies was determined by using the giant granules of C57BL/6-bgJ/bgJ mice as a marker: even when mixture of peritoneal cells of C57BL/6-bgJ/bgJ mice and C57BL/6-+/+ mice were plated, all of the resulting colonies consisted of either bgJ/bgJ-type mast cells alone or +/+-type mast cells alone. Individual mast c 11 colonies of WBB6F1-+/+ mouse origin were divided into two parts; one part was directly injected into the wall of the glandular stomach of a WBB6F1-W/Wv mouse, and another part was injected into the skin of the same W/Wv mouse. Injections of 14 of 46 such colonies resulted in development of mast cells in both the "connective tissues" (skin or stomach muscle or both) and the stomach mucosa. Mast cells in the connective tissues were stained with Berberine-sulfate, indicating that they contained heparin, whereas mast cells in the stomach mucosa were not. These results suggest that a single precursor cell can give rise to both "connective tissue-type" and "mucosal" mast cells.
Mechanisms of self-cure from Trypanosoma congolense infection in mice.
Authors: Pinder M , Chassin P , Fumoux F
Published: December 2022

The mechanism(s) of resistance to African trypanosomiasis caused by Trypanosoma congolense was investigated by using the Dinderesso/80/CRTA/3 isolate to which C57B1/6 are resistant (low parasitemia and self-cure) and BALB/c sensitive (high parasitemia and death). The resistance of C57B1/6 is similar to that found in some natural hosts of African trypanosomes such as certain indigenous West African cattle and wild Bovidae. The antibody response to epitopes exposed on the variant surface glycoprotein of a clone obtained from the Dinderesso/80/CRTA/3 isolate was measured by a complement-mediated lysis assay in C57B1/6 and BALB/c. After infections with 10(4), 10(5), or 10(7) motile organisms, antibody appeared in C57B1/6 4 to 8 days earlier than in BALB/c. Peak antibody titers were similar in both strains but were reached about 4 days earlier in C57B1/6. In this strain, antibody appeared during and controlled the first wave of parasitemia, whereas in BALB/c, parasitemia reached a plateau above 10(8) organisms per ml before antibody could be detected, and at this time the animals were dying. At peak antibody response, the proportion of immunoglobulin (Ig) M and IgG antibody was the same in both strains. The antibody response had the same kinetics in C57B1/6 and BALB/c after injection of 10(4), 10(5), and 10(7) lethally irradiated but intact parasites, but the peak titers were 10(3) to 10(4) times lower than after live challenge. The response to nonirradiated trypanosomes appeared to be T cell independent, because the antibody titers were the same in congenitally athymic nu/nu and normal C57B1/6, and no evidence for the induction of T cell activity could be demonstrated in the infected nude mice. A role for trypanolytic serum factors in resistance could not be demonstrated. The extent of immunosuppression after infection with nonirradiated organisms was compared in the two strains by measuring the in vitro response of their splenic lymphocytes to concanavalin A, pokeweed mitogen, and allogeneic cells and their ability to mount an in vivo response to an unrelated trypanosome challenge. Both strains were partially immunosuppressed during rising parasitemia, but as C57B1/6 controlled parasitemia, immunosuppression was gradually reversed, whereas in BALB/c it became worse. Several explanations might account for the resistance of C57B1/6 to the Dinderesso/80/CRTA/3 isolate of T. congolense. It appears that an early immune response is a decisive factor in this resistance.
Isotype-like suppression of T cell-mediated immunity in vivo. II. Suppression of the early component of contact sensitivity by a Ly-2+ T cell-derived suppressor factor that binds to contact sensitivity-initiating, antigen-specific, Ly-1+ T cell-derived factors that are of different antigen specificities.
Authors: Ptak W , Bereta M , Ptak M , Askenase P W
Published: December 2022

Recognition that delayed-type hypersensitivity (DTH) reactions, such as contact sensitivity (CS) in mice, are initiated by Ly-1+ T cell-derived, antigen-specific factors has led to identification of a new kind of suppressor T cell that regulates this initiation phase of CS. Regulation by these suppressor T cells is T cell isotype-like in that initiation of DTH of various antigenic specificities is suppressed, whereas, Ly-1+ T cells mediating the antigen/major histocompatibility complex-restricted, classic delayed phase of CS responses are not affected, nor are other T cell activities. This study shows that these isotype-specific suppressor T cells probably act by release of soluble, isotype-specific, suppressor factors. These isotype-specific T cell factors bind to and can be eluted from columns linked with antigen-specific Ly-1+ T cell factors that initiate CS, and are of different antigen specificities. These T cell regulating, anti-isotypic suppressor factors are derived from Lyt-2+ I-J- T cells and suppress CS-initiating T cells, but do not affect the delayed-acting T cells of CS. This is in contrast with antigen-specific T cell suppressor factors that affect the late-acting and not the early-acting T cells of CS. It is suggested that the antigen-binding, CS-initiating, T cell factors, and their regulatory, anti-isotypic T cell factors are, respectively, T cell analogues of immunoglobulin(Ig)E antibody, and IgE-binding factors, that regulate IgE antibody production by IgE+ B cells.
In vitro production of interleukin 1 by normal and malignant human B lymphocytes.
Authors: Pistoia V , Cozzolino F , Rubartelli A , Torcia M , Roncella S , Ferrarini M
Published: December 2022

In this study, the capacity of normal and neoplastic B lymphocytes to release interleukin 1 (IL 1) has been investigated. Peripheral blood B cells from normal donors were isolated by depletion of E rosetting cells and by positive selection of cells expressing surface immunoglobulin (sIg) or the B1 marker. Peripheral blood B cells from patients with B cell chronic lymphocytic leukemia (B-CLL) were purified by removal of E rosetting cells followed by complement-mediated cytotoxicity with selected monoclonal antibodies. All of the normal B cell suspensions and the large majority of the B-CLL cells produced in culture high amounts of IL 1 in the absence of any apparent stimulus. Control experiments ruled out that small numbers of monocytes in the B cell suspensions could represent the source of IL 1. These data support the contention that B cells participate to the immune response as accessory cells for T cell activation not only by physically presenting antigen, but also by releasing IL 1.
Regulation of interleukin 2 receptor expression on a human cytotoxic T lymphocyte clone, synergism between alloantigenic stimulation and interleukin 2.
Authors: Jacques Y , Le Mauff B , Godard A , Olive D , Moreau J F , Soulillou J P
Published: December 2022

A human T cell clone (termed 40.2.6) established from a rejected human kidney allograft has been studied for its ability to express membrane IL 2 receptors in response to antigen (irradiated cells from the graft's donor) and recombinant IL 2 (rec-IL 2). On antigenic stimulation, the 40.2.6 clone produced low levels (0.15 U/ml) of IL 2 (peak at 24 hr) and incorporated (3H)thymidine (peak at 48 hr). This incorporation was strongly enhanced on addition of rec-IL 2 and was inhibited by the 33B31 antibody, an anti-human IL 2 receptor monoclonal antibody (Mab). The 125I-labeled 33B31 Mab has been used to quantify the density of IL 2 receptors on 40.2.6 cells. Cells not re-exposed to antigen or rec-IL 2 had a level of 33B31-binding sites which declined rapidly (10% of starting value after 2 days). This level remained much more stable when rec-IL 2 (1 U/ml) was present in the medium (80% at day 2). Antigen induced a three- to eightfold increase in the level of 33B31-binding sites which peaked at 24 hr and then declined. When a similar antigenic stimulation was performed in the presence of rec-IL 2 (1 U/ml), the level of 33B31-binding sites peaked at a higher value (eight- to 20-fold increase at day 2), and its subsequent decline was slower. These potentiating effects of rec-IL 2 were dose-dependent and occurred at low concentrations corresponding to the saturation by rec-IL 2 of high affinity IL 2 receptor sites. Finally, high affinity IL 2 receptors, as measured by the binding of 35S-labeled rec-IL 2, were found to be similarly up-regulated by antigen and rec-IL 2. Together, our results obtained on a monoclonal human T cell population with highly purified rec-IL 2 demonstrate that rec-IL 2 and antigen act in synergy to induce the expression of both high and low affinity membrane IL 2 receptors.
Natural antibodies to interferon-alpha and interferon-beta are a common feature of inbred mouse strains.
Authors: De Maeyer-Guignard J , De Maeyer E
Published: December 2022

Neutralizing antibodies to murine interferon-alpha (MuIFN-alpha) and MuIFN-beta of the immunoglobulin (Ig)G and IgM class were naturally present in sera of BALB/c and C57BL/6 mice of four different age groups, ranging from 1 to 15 mo. These antibodies not only neutralized IFN made by C-243 cells (Swiss genotype), but also isogenic IFN-alpha and IFN-beta, and can therefore be considered to be real autoantibodies. Natural anti-MuIFN antibodies were also found in the sera of mice from 12 other inbred strains, and seem to be a common feature of inbred mouse strains.
Isolation and partial characterization of an eosinophil chemotactic factor from metacestodes of Taenia taeniaeformis (ECF-Tt).
Authors: Potter K A , Leid R W
Published: December 2022

Eosinophil chemotactic activity associated with protein extracts of Taenia taeniaeformis metacestodes was investigated. Chemotactic activity was associated with the nonbound protein after QAE cellulose chromatography of a 3 M KCl extract of homogenized larvae. When this material was precipitated with ammonium sulfate, activity was present in the 40 to 80% precipitate. Upon rechromatography on QAE cellulose equilibrated in a low ionic strength buffer, eosinophil chemotactic activity was retained by the gel and eluted after application of the NaCl gradient. Gel filtration of Sephacryl S-300 yielded an estimated m.w. of 91,000. Chromatofocusing revealed a broad peak of activity with a pI of 4.5 to 5.0. SDS-PAGE showed the active fraction migrated as a protein with a m.w. of 10,400. ECF-Tt had chemotactic and chemokinetic activity for equine eosinophils and murine eosinophils, but not for equine and murine neutrophils.
Recognition of HLA class I molecules by antisera directed to synthetic peptides corresponding to different regions of the HLA-B7 heavy chain.
Authors: Choppin J , Metzger J J , Bouillot M , Briand J P , Connan F , Van Regenmortel M H , Levy J P
Published: December 2022

Antisera have been prepared in rabbits and in mice against different peptides corresponding to four hydrophilic and variable regions of HLA-B7 heavy chain (65-82, 99-118, 138-157, and 164-187). Specific antipeptide sera have been obtained with all synthetic peptides; for three of them which were more than 20 amino acids long, highly potent sera were elicited by injection of the free peptide. Three overlapping peptides included in region 138-157 have been used, and two different antigenic sites were detected in this region. HLA molecules solubilized in nonionic detergent were precipitated by antipeptide sera directed against regions 65-82, 138-157, and 164-187, but not by antipeptide serum directed against the less hydrophilic region 99-118. Analysis by two-dimensional electrophoresis of the isolated molecules confirmed the anti-HLA specificity of the antipeptide 65-82 and 138-157 sera. Variable numbers of HLA-related spots were found according to the antisera used. Antipeptide 138-157 serum precipitated numerous HLA molecules and therefore probably reacted with monomorphic determinants whereas antipeptide 65-82 appeared specific for a more limited number of HLA antigens. Such reagents directed against well-defined regions of the HLA class I heavy chain are of considerable interest, notably for the mapping of antigenic epitopes on the molecule and for the study of relationships between structure and function.
Biochemical analysis suggests distinct functional roles for the BLAST-1 and BLAST-2 antigens.
Authors: Thorley-Lawson D A , Swendeman S L , Edson C M
Published: December 2022

The biochemical processing of the BLAST-1 and BLAST-2 activation antigens has been studied. Both are glycoproteins that derive from different precursors of the same apparent m.w. on SDS-PAGE. BLAST-1 is synthesized as a 43,000 m.w. light chain in association with a second heavier chain of 55,000 m.w. The light chain acquires sialylated O-linked glycans and is stably expressed at the cell surface with a half-life of 14 hr. BLAST-2 is also synthesized as a 43,000 m.w. precursor, but it acquires only unsialylated N-linked glycans. The mature glycoprotein is only expressed briefly at the cell surface (half-life of 1 to 2 hr), and is then shed into the culture supernatant as a soluble 33,000 m.w. derivative. The different fates of these molecules, one stably expressed at the cell surface and one shed, suggest disparate roles for these two antigens in B cell activation.
Binding and catabolism of aggregated immunoglobulins containing C3b by U937 cells.
Authors: Mehta R L , Takahashi H , Rudick R A , Knutson D W
Published: December 2022

We studied Fc receptor and C3b receptor (CR1) function on U937 cells, a human monocyte cell line. C3b was incorporated into stable soluble heat aggregates of 125I-IgM (A-IgM) and 125I-IgG (A-IgG) by using functionally pure classical pathway components. C3b incorporation was verified by the ability of aggregates to bind to human red cells and by cosedimentation of 125I and 131I during ultracentrifugation. Cell uptake and degradation of A-IgG X C3b was increased up to twofold compared with A-IgG not containing C3b molecules. However, A-IgG X C3b bound to CR1 after Fc receptors were blocked with nonradiolabeled A-IgG were also not endocytosed and catabolized. Moreover, A-IgM X C3b was bound but not degraded by U937 cells. As expected, uptake of A-IgM without C3b was negligible. CR1-mediated binding of A-IgM X C3b was specifically inhibited both by a murine monoclonal antibody against the human CR1 that blocks C3b binding and by C3b oligomers generated by trypsin activation of C3, but not by monoclonal antibodies against the iC3b receptor (CR3). We conclude that CR1 on U937 cells cause increased binding of A-IgG, and this increased binding leads to increased Fc-mediated endocytosis and catabolism of model immune complexes. However, binding of soluble ligands by CR1 alone, even when binding is multivalent, does not lead to endocytosis and degradation of soluble ligands bearing C3b.
Cells with natural killer activity in the cerebrospinal fluid of normal mice and athymic nude mice with acute Sindbis virus encephalitis.
Authors: Griffin D E , Hess J L
Published: December 2022

Sindbis virus causes an acute, nonfatal inflammatory encephalitis in weanling BALB/c mice. Mononuclear inflammatory cells are present in the cerebrospinal fluid (CSF) as well as in the parenchyma of the brain. Both aspects of this inflammatory response were eliminated by treatment with cyclophosphamide. Athymic nude (nu/nu) mice developed no inflammation in the brain, but did develop a CSF pleocytosis that peaked on day 2 after infection. The time course of the appearance of cells in the CSF was earlier in nu/nu mice than their heterozygote (nu/+) littermates. The pleocytosis in nu/nu mice reached a peak on day 2, whereas in nu/+ mice the peak was on day 4, as it is in normal BALB/c mice. To determine whether some of the CSF cells in nu/nu mice may be natural killer (NK) cells, NK activity was measured in a 4-hr assay by using a YAC-1 target cell. NK cell activity in the spleen and peripheral blood was induced by infection with Sindbis virus in nu/nu mice with a similar time course to that of nu/+ mice (peak 1 day after infection). CSF from nu/nu mice had NK activity present 2 days after infection that was greater than that present in either the peripheral blood or spleen. BALB/c and nu/+ mice had insufficient cells present for assay at day 2, but BALB/c mice had NK activity present in the CSF 3 and 5 days after infection that exceeded that in the peripheral blood or spleen. Brain interferon was detectable on day 1 in nu/nu mice, but not until day 2 in nu/+ mice even though the amounts of brain virus were the same in the two groups at all time points. It is concluded that cells with NK activity contribute to the CSF pleocytosis induced by acute Sindbis virus encephalitis.
The role of T cell accessory molecules in the generation of class II-specific xenogeneic cytolytic T cells.
Authors: Greenstein J L , Foran J A , Gorga J C , Burakoff S J
Published: December 2022

In the generation of allogeneic, hapten-modified and virus-specific cytotoxic T cell (CTL) responses there is usually a requirement for T-T interaction between the T helper cell (TH) and the precursor CTL (CTL). We have investigated the role of a TH signal in the induction of a xenogeneic mouse antihuman CTL response by using membranes and liposomes bearing the xenogeneic antigen to stimulate primed responders. The TH signal can be achieved by either an Ia-restricted, L3T4+ DR-specific T cell or by the addition of nonspecific T helper factors(s). This signal is delivered to an Lyt-2+, L3T4-DR-specific CTL to generate active xenogeneic (xeno-) CTL. The roles of the T cell accessory molecules L3T4, Lyt-2, and LFA-1 in the generation of and target cell lysis by xeno-CTL are investigated.
Multiple epitopes in a dodecapeptide of myelin basic protein determined by monoclonal antibodies.
Authors: Price J O , Whitaker J N , Vasu R I , Metzger D W
Published: December 2022

Three custom synthesized myelin basic protein (MBP) peptides, bovine peptide 79-88, human peptide 80-89, and human peptide 82-91, were used to produce four murine monoclonal antibodies (MAb) that were selected on the basis of reaction in a solid phase radioimmunoassay (SRIA) with human MBP. The MAb were compared with respect to antigen specificity against intact MBP and 10 overlapping MBP peptides. One MAb recognized an epitope near the amino-terminus of bovine MBP peptide 79-88. A second MAb was directed towards an epitope that is more reactive in human MBP peptide 45-89 than in intact MBP, but is not recognized in any of the small MBP peptides examined. The third MAb detected an epitope near the middle of human MBP peptide 80-89, whereas the fourth MAb reacted with the carboxyl-terminal portion of human MBP peptide 82-91. Epitopes recognized in SRIA were sometimes not detected by the same MAb in a fluid phase double antibody radioimmunoassay. These results demonstrate the multiplicity of potential epitopes in a dodecapeptide of MBP and do not support the concept of a single, dominant epitope in the region of MBP peptide 80-89.
Binding and cross-linking of recombinant mouse interferon-gamma to receptors in mouse leukemic L1210 cells; interferon-gamma internalization and receptor down-regulation.
Authors: Wietzerbin J , Gaudelet C , Aguet M , Falcoff E
Published: December 2022

Recombinant E. coli-derived murine IFN-gamma (Mu-rIFN-gamma; 5 X 10(7) U/mg) was radiolabeled with 125I by the chloramine-T method without loss of its antiviral activity. The 125I-Mu-rIFN-gamma showed specific binding to L1210 cells. Scatchard analysis indicates about 4000 binding sites per cell and an apparent Kd of 5 X 10(-10)M. Binding of 125I-Mu-rIFN-gamma to cells was inhibited by both natural (glycosylated) and rIFN-gamma, but not by IFN-alpha/beta. Receptor-bound 125I-Mu-rIFN-gamma was rapidly internalized when incubation temperature was raised from 4 degrees C to 37 degrees C. On internalization, almost no IFN-gamma degradation was observed during 16 hr incubation. 125I-Mu-rIFN-gamma binding capacity decreased in cells preincubated with low doses of unlabeled Mu-rIFN-gamma, but not with IFN-alpha/beta. This receptor down-regulation was dose-dependent: 90% reduction of 125I-Mu-rIFN-gamma binding was observed after preincubation with 100 U/ml. After removal of IFN-gamma from the culture medium, the binding capacity increased with time. However, reappearance of receptor was completely blocked by cycloheximide or tunicamycin, suggesting that re-expression of receptors is not due to recycling but to the synthesis of new receptors, and that the receptor is probably a glycoprotein. Cross-linking of 125I-Mu-rIFN-gamma to surface L1210 cell proteins by using bifunctional agents yielded a predominant complex of m.w. 110,000 +/- 5000. Thus, assuming a bimolecular complex, the m.w. of the receptor or receptor subunit would be close to 95,000 +/- 5000. The formation of such a complex appeared highly specific on the basis of the following criteria: it could be inhibited by the addition of Mu-rIFN-gamma but not by Mu-rIFN-alpha/beta, it was not obtained in cells pretreated with IFN-gamma to induce down-regulation of IFN-gamma receptors, and it was also identified in the IFN-alpha/beta-resistant L1210R cell line, known to be sensitive to IFN-gamma and which we have recently shown to express IFN-gamma receptors.
Histamine-induced suppressor factor inhibition of NK cells: reversal with interferon and interleukin 2.
Authors: Nair M P , Cilik J M , Schwartz S A
Published: December 2022

Culture supernatants of lymphocytes stimulated with 10(-3) to 10(-8) M histamine contain histamine-induced soluble suppressor factor (HISSF) that significantly inhibits the natural killer (NK) cell functions of allogeneic lymphocytes. Lymphocytes precultured with increasing concentrations of HISSF showed a dose-dependent suppressive effect on their NK activity. HISSF was not cytotoxic itself and produced suppressive effects on PBL, NK-enriched large granular lymphocytes (LGL), and isolated T cells. Suppression was evident throughout a range of effector:target cell ratios. Production of HISSF was specifically blocked by the H2 antagonist cimetidine, but not by the H1 antagonist clemastine fumarate. Furthermore, H1 and H2 antagonists themselves do not induce production of HISSF. Although HISSF could inhibit the cytotoxicity of LGL, LGL themselves do not produce HISSF. HISSF inhibition of NK activity could be completely reversed by treating effector lymphocytes with recombinant interferon-alpha (IFN) for 1 or 2 hr or culturing them with purified interleukin 2(IL 2) for 36 hr. Our data suggest that exogenous IFN and IL 2 may have therapeutic potential in the treatment of immunological diseases associated with histamine-induced suppressor cell activity.
Production of interleukin 1 by human endothelial cells.
Authors: Miossec P , Cavender D , Ziff M
Published: December 2022

Vascular endothelial cells (EC) play an important role in the emigration from the blood of the mononuclear cells that participate in the chronic inflammatory response. Because EC express a number of functions of cells of the monocyte/macrophage lineage, EC culture supernatants (ECSN) were examined for the presence of IL 1. In these supernatants, IL 1 activity was low when EC were cultured in the presence of serum. The low level of activity appeared to be due to the spontaneous production by the EC of inhibitors of the thymocyte proliferation assay of IL 1, of 70 kd and 9 kd, as measured by AcA Ultrogel filtration. When EC were cultured in the absence of serum, IL 1 activity was easily demonstrated in crude supernatants. Upon stimulation with LPS, the amounts of IL 1 activity were greatly increased. The release of IL 1 was an early event, detectable after 1 hr of incubation and reaching a maximum after 24 hr. The IL 1 activity produced by EC demonstrated a number of similarities to that of IL 1 produced by monocytes. On AcA 54 gel filtration, as with monocyte-derived IL 1, the IL 1 activity was found in two peaks of 50 to 60 kd and 16 to 18 kd. Upon chromatofocusing of the 16 to 18 kd peak, three active fractions were found, eluting near pH 7.0, 5.6, and 5.0. In addition, when LPS-stimulated ECSN and purified monocyte-derived IL 1 were incubated with a rabbit anti-IL 1 antibody, a parallel reduction in thymocyte-stimulating activity was observed, suggesting that the active agent in ECSN shared a common antigenic site with IL 1. The demonstration of IL 1 production by EC provides additional evidence that these cells, in addition to their functions as vascular cells, may also participate in some of the immune and nonimmune functions previously ascribed to macrophages.
Enhancement of plasma levels of biologically active leukotriene B compounds during anaphylaxis in guinea pigs pretreated by indomethacin or by a fish oil-enriched diet.
Authors: Lee T H , Israel E , Drazen J M , Leitch A G , Ravalese J , Corey E J , Robinson D R , Lewis R A , Austen K F
Published: December 2022

The changes in arterial plasma concentrations of immunoreactive leukotriene B (LTB) were compared after antigen challenge of two groups of sensitized, mepyramine-treated, and mechanically ventilated guinea pigs, one fed a diet enriched with fish oil and the other a control diet enriched with beef tallow. The lung tissue of animals fed a fish oil-enriched diet (FFD) for 9 to 10 wk incorporated eicosapentaenoic acid (EPA) and docosahexaenoic acid to constitute 8 to 9% of total fatty acid content, whereas these alternative fatty acids constituted less than 1% of the total fatty acid content of the lung tissue of animals on a beef tallow-supplemented diet (BFD). The maximum increase after antigen challenge in immunoreactive LTB4 from 0.16 +/- 0.04 ng/ml to 0.84 +/- 0.25 ng/ml in BFD animals and from 0.47 +/- 0.11 to 5.1 +/- 1.4 ng/ml immunoreactive LTB (LTB4 and LTB5) in FFD animals was significant (p less than 0.02) for each. Furthermore, the increase in total immunoreactive LTB in mepyramine-treated FFD animals was significantly greater than the increase in LTB4 in mepyramine-treated BFD guinea pigs at 2 to 8 min after antigen challenge (p less than 0.05). Resolution of arterial plasma immunoreactive LTB from pooled samples by reverse-phase high-performance liquid chromatography demonstrated that the sum of LTB4 and LTB5 in FFD animals exceeded that of LTB4 in BFD animals and that the quantity of LTB4 in the FFD animals was at least as great as that in the BFD animals during anaphylaxis. The products eluting at the retention times of LTB4 and LTB5 exhibited the chemotactic activity of their respective synthetic standards. The combination of indomethacin and mepyramine markedly augmented the antigen-induced increase in arterial plasma immunoreactive LTB4 concentrations in BFD animals, but had no effect on immunoreactive LTB levels in FFD animals. Limited in vivo measurements showing a lesser increase of plasma immunoreactive thromboxane B2 in the FFD relative to the BFD animals during anaphylaxis and ex vivo measurements showing a decreased LTB4-stimulated (cyclooxygenase product-dependent) contractile response of pulmonary parenchymal strips from the FFD relative to the BFD animals provide evidence for blockade in the cyclooxygenase pathway in the FFD animals. The measurements of arterial plasma LTB indicate that indomethacin treatment alone, which inhibits cyclooxygenase activity, and FFD treatment each augment the metabolism of arachidonic acid by the 5-lipoxygenase pathway in animals pretreated with mepyramine.(ABSTRACT TRUNCATED AT 400 WORDS)