bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the Mechanism of Action of Guinea Pig Lymphotoxin
Authors: Okamoto Mitsuhiro , Mayer Manfred M.
Published: December 2022

The effect of various pharmacologic agents on lysis of L cells by guinea pig lymphotoxin (LT) was studied. Among the many drugs tested, only those that affect plasma membrane functions were found to interfere with the cytolytic action of LT. Dimethyl sulfoxide or lidocaine potentiated L cell resistance against lysis. Stronger protection was provided by ouabain. Addition of ouabain to cells previously injured by LT was also effective in reducing cell death. Attempts to detect metabolic disturbances in cells before LT cytolysis were unsuccessful. The biosynthetic rate of DNA, RNA, or protein, and the total cellular content of ATP were not significantly changed in LT-treated cells. The results suggest that LT disturbs some plasma membrane functions of the target cell, perhaps ion transport systems, and consequently induces ionic imbalances between the intra- and extracellular milieu which eventually cause cell death.
The Selective Binding of Aggregated IgG to Lipid A-Rich Bacterial Lipopolysaccharides
Authors: Ginsberg Mark H. , Morrison David C.
Published: December 2022

To explore the mechanism by which certain bacterial lipopolysaccharides (LPS) enhance platelet stimulation by aggregated IgG, we studied potential interactions between the two ligands. Lipid A or the lipid A-rich LPS from Salmonella minnesota R595 (LPS R595) selectively increased the sedimentation of aggregated rather than monomer IgG in sucrose density gradients. Insolubilized IgG aggregates adsorbed LPS R595 from solution. These two experiments suggested binding of IgG aggregates to LPS R595 or lipid A and this was confirmed by isopycnic density gradient ultracentrifugation studies. The presence of R595 LPS shifted the equilibrium density profile of aggregated IgG from its usual equilibrium density at 1.30 g/ml to a new position superimposable with that of the LPS R595. The possibility that a selective binding of IgG aggregates to LPS may represent a fundamental mechanism of the action of LPS on cellular mediation systems is proposed.
Analysis of the Restricted Dinitrophenyl (DNP) Antibody Response to the DNP Conjugate of Poly-(L-Glu56, L-Lys35, L-Phe9)
Authors: Kipps Thomas J. , Benacerraf Baruj , Dorf Martin E.
Published: December 2022

The anti-dinitrophenyl (DNP) response in B10 congenic mice to the DNP conjugate of the random linear terpolymer of L-Glu, L-Lys, L-Phe (GLØ) is restricted in the number of DNP-specific antibody-producing clones expressed as determined by the technique of isoelectric focusing. A limited strain survey indicated that a gene(s) outside the major histocompatibility complex may influence the degree of restriction in the DNP response to DNP-GLØ. Evaluation of sera run in juxtaposition established that a high percentage of B10 congenic mice express a common clone of anti-DNP antibody-producing cells in response to DNP-GLØ. The expression of this clone is independent of H-2 haplotype. These findings contrasted with the extremely heterogeneous populations of anti-DNP antibodies produced in these strains when immunized with DNP-ovalbumin (DNP-OVA). Adoptive transfer experiments revealed, however, that unprimed or GLØ-primed T cells can cooperate with syngeneic DNP-OVA-primed B cell clones to generate a heterogeneous anti-DNP response upon challenge with DNP-GLØ.
Rejection of Allo- or Xenografts of Lymphoid Cells by Nude Mice: T Cell Suicide as a Result of Cooperation between Histoincompatible T and B Cells
Authors: Piguet P. F. , Vassalli P.
Published: December 2022

Athymic nude mice with a BALB/c or C57BL/6 genetic background were given an i.v. injection of allo- (e.g., CBA-T6T6) or xenogeneic (rat) lymphoid cells or purified T lymphocytes. About 1 week after a phase of graft-vs-host reaction, which was manifested by an increase in size of the lymphoid organs and a proliferation of donor T cells (detected by combined immunofluorescence and autoradiography and by caryotypic analysis), the grafted cells were rejected as indicated by 1) reversion of the lymphoid organs to their original size and to the very low initial T cell content or 2) by absence of donor cell mitoses. This was closely correlated with the appearance in the nude mice sera of high titers of cytotoxic antibodies of the IgG class, specifically directed against cells of the donor strain; these sera also seemed to contain anti-donor Ia antibodies. When the allogeneic or xenogeneic lymphoid cell graft was performed on nude mice bearing two foreign skin allografts, one syngeneic and the other allogeneic to the lymphoid graft, no gross signs of skin graft rejection were observed, except after injection of rabbit serum as a source of C. This was followed by an hyperacute rejection of the skin graft syngeneic to the lymphoid graft whereas the unrelated skin graft was unaffected.

Living T cells play an essential role in the strong antidonor humoral response of the nude mice, since nude mice injected with histoincompatible B cells or with lymphoid cells inactivated with slight formaldehyde fixation showed only an inconstant, very weak, and transient humoral response. The reaction of nude mice to foreign lymphoid grafts therefore implies a peculiar form of T-B cell cooperation across the histocompatibility or species barrier, in which the grafted T cells, recognizing the nude mice antigens, help the nude B cells make antibodies against the graft, thus leading to their own rejection.
On the Cross-Reactivity of Staphylococcal Enterotoxins A, B, and C
Authors: Spero Leonard , Morlock Beverly A. , Metzger Joseph F.
Published: December 2022

Strong cross-reactions were demonstrated for staphylococcal enterotoxins B (SEB) and C1 (SEC1) by antigenbinding capacity and by competitive binding ability. Both SEB and SEC1 combined completely with the heterologous antibody although requiring four times as much antiserum as the homologous enterotoxin and both displaced about one-third of the other enterotoxin from a heterologous antigen-antibody system. It is proposed that one of the three major antigenic determinants of these enterotoxins possesses a significant similarity but probably not an identity of structure.

SEB and SEC1 did not combine with antiserum to enterotoxin A nor inhibit the reaction of SEA with anti-SEA. SEA had no intrinsic binding capacity for anti-SEB or anti-SEC1 nor did it inhibit the binding of either enterotoxin to its own antibody. Affinity chromatography was employed to demonstrate that a small apparent binding of SEA to anti-SEB was due to antibody to SEA in the anti-SEB serum and that an almost complete displacement of SEC1 binding to anti-SEC1 was caused by contaminating SEC (about 0.01%) in preparations of enterotoxin A.
Rosette Formation by the Human K Cell
Authors: West William H. , Boozer R. Bryan , Herberman Ronald B.
Published: December 2022

Human T lymphocytes were separated into two subsets on the basis of relative affinity for sheep red blood cells (E), and these T cell fractions were examined for cytotoxic reactivity against antibody-sensitized Chang liver cells (ADCC). High affinity E-rosette-forming cells (E-RFC) (55 ± 6% of peripheral blood mononuclear cells), capable of rosette formation despite elevated temperatures of incubation (29°C) and a limited concentration of E, contained few antibody-dependent cytotoxic cells (K cells). In contrast, low affinity E-RFC (23 ± 7% of mononuclear cell suspensions) requiring cool temperatures of incubation (4°C) and an excess of E to form rosettes, were highly enriched for ADCC activity. The majority of K cells exhibited low affinity interactions with E. T cells in thymus, tonsil, and lymph node formed high affinity E-rosettes and exhibited little reactivity in ADCC. Only peripheral blood and spleen contained easily identified low affinity E-RFC and antibody-dependent cytotoxic cells. The proportion of low affinity E-RFC in the peripheral blood of normal subjects correlated closely with reactivity in ADCC, making it possible to predict cytotoxic potential from the E-rosette pattern. These data indicate that the human K cell may belong to a previously unappreciated but functionally important subset of thymic dependent mononuclear cells.
Cell Surface Immunoglobulin
Authors: Yuan Dorothy , Vitetta Ellen S.
Published: December 2022

The differentiation of Ig-bearing lymphocytes in adult mice was studied by monitoring the appearance of IgD relative to IgM on the surface of splenocytes obtained from lethally irradiated animals reconstituted for various periods of time with adult bone marrow cells, neonatal splenocytes, or Ig- adult splenocytes. It was found that IgM appears before IgD on differentiating lymphocytes. Furthermore, the rate of appearance of IgD during differentiation of adult cells is similar to that observed with neonatal cells.
Suppression of the Plaque-Forming Cell Response by Macrophages Present in the Normal Rat Spleen
Authors: Weiss Arthur , Fitch Frank W.
Published: December 2022

Depletion of phagocytic and/or adherent cells from normal rat spleen cell preparations permitted the generation of PFC to SRBC in vitro. Suppressive activity was associated with the presence of macrophages in the normal rat spleen, since irradiated unfractionated or irradiated adherent cells suppressed the PFC response of macrophage-depleted cells. Whereas depletion of macrophages from normal rat spleen cells permitted the PFC response to SRBC to occur, comparable treatment of mouse spleen cells eliminated the PFC response. These results are discussed in relation to the requirement for macrophages in the generation of PFC with rat cells in vitro.
Binding Studies on Heavy-Light Chain Recombinant Hybrid Immunoglobulins a Derived from Murine Myeloma Anti-Fructofuranans
Authors: Streefkerk Dirk G. , Vrana Mark , Glaudemans Cornelis P. J.
Published: December 2022

Heterologous H-L chain recombinants derived from homogeneous murine myeloma immunoglobulins with anti-inulin specificity were found to bind inulin-related oligosaccharides with affinities closely paralleling those of the L chain donors.
Cellular Mechanisms of Cholera Toxin-Mediated Modulation of in Vitro Hemolysin Formation by Mouse Immunocytes
Authors: Lyons Susan F. , Friedman Herman
Published: December 2022

Cholera exoenterotoxin (CT) from Vibrio bacilli enhances antibody responses when administered together with an antigen such as sheep erythrocytes but suppresses immune responses when given several days before antigen. Although CT is known to stimulate adenylate cyclase activity and alters cyclic AMP levels in lymphoid as well as nonlymphoid tissues, the mechanisms of immunologic modulation by the toxin are unknown. In the present study the in vitro hemolytic antibody plaque response to sheep red blood cells was found to be markedly enhanced when splenocytes were obtained from mice treated with CT on the day of culture initiation or 1 day earlier, similar to the enhancement of antibody formation in vivo when mice were given CT and antigen at the same time. Spleen cells from mice treated 2 to 3 days earlier with CT, however, showed marked impairment of in vitro responsiveness to sheep erythrocytes, similar to the immunosuppression observed in vivo in toxin-pretreated mice. In contrast, CT induced only an enhanced antibody response when added to normal spleen cells in vitro, either on the day of culture initiation and immunization or 2 days earlier, suggesting that suppression of immunity induced by CT pretreatment in vivo is due to an indirect effect on cells other than immunocytes. This was substantiated by experiments with adrenalectomized mice since only enhancement and not suppression of antibody responses occurred. Impairment of spleen cell responsiveness from CT-pretreated mice could be partially restored by addition of PE cells and fully restored by “educated” T cells derived from recipient mice given thymocytes and SRBC. Thus, CT suppression of antibody formation may be due to an indirect effect on specific cell populations, whereas immune enhancement was probably due to a direct adjuvant effect of the toxin on immunocytes or their precursor.
Chemotactic and Chemokinetic Stimulation of Human Eosinophil and Neutrophil Polymorphonuclear Leukocytes by 12-L-Hydroxy-5,8,10-Heptadecatrienoic Acid (HHT)
Authors: Goetzl Edward J. , Gorman Robert R.
Published: December 2022

Diverse lipid products of arachidonic acid were examined for in vitro human polymorphonuclear (PMN) leukocyte chemotactic activity and the ability to enhance PMN leukocyte migration in the absence of a concentration gradient of the stimulus, an effect termed chemokinesis. Highly purified 12-L-hydroxy-5,8,10-eicosatetraenoic acid (HETE), a lipoxygenase product, and 12-L-hydroxy-5,8,10-heptadecatrienoic acid (HHT), a cyclo-oxygenase product, were chemotactic for PMN leukocytes in concentrations ranging from 0.7 to 25 µg/ml and 2 to 50 µg/ml, respectively, with a preference for the eosinophil series. Preincubation with peak chemotactic concentrations of either hydroxy-lipid product irreversibly suppressed the response of PMN leukocytes to the homologous and other chemotactic stimuli. At minimally chemotactic concentrations, both HETE and HHT were positively chemokinetic and enhanced the chemotactic response of PMN leukocytes to the homologous lipid and to a stimulus derived from human C5 by tryptic digestion. PGE2 and PGF2α lacked chemotactic activity, but exhibited negative and positive chemokinetic activity, respectively, whereas thromboxane B2 had no effect on PMN leukocyte migration. Thus, HHT is the first leukocyte chemotactic factor that is a product of the cyclooxygenase pathway and whose generation would thus be inhibited by nonsteroidal anti-inflammatory agents. Unlike the potently deactivating chemotactic factors, such as the tetrapeptides of the eosinophil chemotactic factor of anaphylaxis (ECF-A), HHT and HETE are chemokinetic at low concentrations and may enhance PMN leukocyte influx in response to other chemotactic stimuli.
Studies on Cellular Receptors for Lymphokines
Authors: Amsden Adele , Ewan Veeta , Yoshida Takeshi , Cohen Stanley
Published: December 2022

In contrast to previous reports, L-rhamnose as well as L-fucose is capable of inhibiting guinea pig migration inhibition factor (MIF) activity. These sugars also inhibit the activity of macrophage chemotactic and neutrophil chemotactic factors. Thus, fucose is not a specific inhibitor of MIF, nor is its activity confined to that lymphokine.

Preincubation of L-fucose or L-rhamnose with the lymphokines was required for inhibition of chemotactic activity. This finding, as well as the results of dose-response experiments, suggest that the mechanism of chemotactic inhibition is similar to the mechanism of inhibition of MIF by monosaccharides; i.e., that the lymphokines possess receptor sites that recognize cell sites bearing a structural or conformational similarity to these sugars. In contrast, L-xylose, the only other sugar found inhibitory in the present study, appeared to exert its activity by a direct effect on the target cells themselves rather than by interaction with the mediator.

Dose-response studies demonstrate that the effect of L-fucose on inhibition of either lymphokine activity is inversely proportional to the amount of lymphokine activity initially present.

A major finding that emerged from the present study is that the monosaccharide inhibition of inflammatory mediator activity appears to be confined to either lymphokines themselves or cytokines (lymphokine-like factors derived from nonlymphoid cells). Three other biologic mediators with chemotactic activity, fragments from trypsin-treated C3 and C5, and bacterial factor, could not be inhibited by either L-fucose or L-rhamnose. The apparent inhibitory effect of L-xylose for bacterial factor activity does not negate this conclusion, since as stated above, this sugar appears to interact with the target cell rather than the mediator. Aside from theoretical considerations, this finding may be of considerable practical importance since it could provide a simple way to distinguish different sources of chemotactic activity in complex biologic mixtures such as serum or tissue extracts.

Based upon current data and the results of previous studies, we have postulated that the inflammatory mediators (lymphokines) have two binding sites, one to allow for recognition of the appropriate target cells, and the other which determines the specific biologic activity.
The Reaction of Sle Antibodies with Native, Single Stranded Rna: Radioassay and Binding Specificities
Authors: Eilat Dan , Steinberg Alfred D. , Schechter Alan N.
Published: December 2022

Escherichia coli 3H-tRNA and MS2 phage 125I-RNA were prepared and used in a sensitive nitrocellulose filter assay. Antibodies that bound these RNA ligands occurred in the sera of several patients with SLE, but not in sera of patients with other connective tissue diseases. The antibody populations that bound polyribonucleotides (largely IgG) were distinct from antibody populations that bound polydeoxyribonucleotides. Competition experiments showed that the anti-RNA antibodies preferentially bound native ssRNA as compared with synthetic single and double stranded polyribonucleotides. There was increasing affinity with increasing m.w. of the ssRNA. The anti-tRNA population was of restricted heterogeneity (Sips index 0.83) and bound tRNA with an average association constant (Ko) of 9 × 106 1/mole at 4°C. The anti-MS2 RNA population was much more heterogeneous (Sips index 0.67) and bound MS2 RNA with a Ko of about 3 × 109 1/mole at 4°C. Whereas NZB/NZW mice spontaneously produce RNA reactive antibodies with conformation specificity for native tRNA, human SLE anti-RNA antibodies appear to have very little of this type of conformation specificity.
Detection of Ia Antigens on Langerhans Cells in Guinea Pig Skin
Authors: Stingl Georg , Katz Stephen I. , Shevach Ethan M. , Wolff-Schreiner Elisabeth , Green Ira
Published: December 2022

Langerhans cells (LC) constitute a small proportion of the mammalian epidermal cells and may be identified by their unique ultrastructural appearance. Of all the cells in the guinea pig epidermis, only Langerhans cells—as defined by ultrastructural criteria—form rosettes with IgG antibody-coated BRBC. Using this rosette assay for the identification of LC and an indirect immunofluorescent technique with FITC-SPA as a marker to detect antigens of the guinea pig MHC, we have investigated whether guinea pig LC bear Ia antigens. Rosette-forming epidermal cells (RF-EC)—identical to LC—from strain 2 animals bound only an anti-strain 2 antiserum, but not an anti-strain 13 antiserum or NGPS and, in reverse fashion, RF-EC from strain 13 animals bound an anti-strain 13 antiserum, but not an anti-strain 2 antiserum or NGPS. LC from (2 × 13)F1 animals reacted with both an anti-strain 2 and anti-strain 13 antiserum, but not with NGPS. Non-RF-EC did not bind any of the anti-Ia antisera. An anti-B.1 antiserum, by contrast, reacted with all epidermal cells from strain 2, strain 13, and (2 × 13)F1 animals (known to share in common B.1 antigens), but not with epidermal cells from a B.3 animal. These results demonstrate that Ia antigens in guinea pig epidermis are selectively expressed on LC, whereas GPLA-B region antigens can be detected on all epidermal cells. Fc-IgG rosette formation by LC can be inhibited by either the specific anti-Ia antiserum or by specific anti-B region antisera, which seems to indicate that antibodies against various antigenic determinants on LC may provoke subtle membrane changes resulting in Fc receptor blockade.

The finding of Fc receptors along with the expression of Ia antigens on the surface of LC supports the concept of their being involved in the afferent limb of the immune response.
Identification of a Tumor-Associated Antigen of the Guinea Pig L2C Leukemia by Using Syngeneic Antisera
Authors: Hu Cheng-Po , Schwartz Benjamin D. , Green Ira
Published: December 2022

Inbred strain 2 guinea pigs immunized with L2C leukemia cells produced antibodies to L2C cells detected by 125I-protein A assay. L2C-associated tumor antigens were reacted with syngeneic antisera and analyzed by immunoprecipitation and SDS-polyacrylamide gel electrophoresis. These sera recognized idiotypic determinants on surface IgM molecules of L2C cells but did not recognize any determinants on normal strain 2 spleen cells. Thus, determinants on IgM molecules act as tumor-associated antigens in the L2C system and can be detected by syngeneic sera.
Suppression of Experimental Allergic Encephalomyelitis by 6-Hydroxyphthalaldehydic Acid, O-(p-Chlorobenzyl)Oxime (EN3638)
Authors: Levine Seymour , Sowinski Richard
Published: December 2022

EN3638 is a new oxime derivative of salicylic acid that has immunosuppressive properties. Oral administration of the compound to rats during the incubation period of experimental allergic encephalomyelitis (EAE) delayed the onset of clinical signs. EN3638 was effective in both ordinary and hyperacute forms of EAE. Doses of 50, 100, or 150 mg/kg daily, 250 mg/kg three times a week, or 400 mg/kg twice a week suppressed both clinical and histologic evidences of EAE during the course of therapy (as long as 4 weeks) and for 8 or more days thereafter. Clinical EAE developed after a full incubation period after discontinuance of EN3638, probably due to the persisting depot of antigen in oil. When EAE was produced without an oily depot, a single dose suppressed the disease for at least 5 weeks in some rats. EN3638 was effective when given only in the second half of the incubation period but not when given at the time that EAE lesions and signs develop. Passive transfer experiments suggested that the drug prevented and even reversed sensitization to neural antigens. It had only slight effect on fully sensitized lymphoid cells or on the recruitment of nonimmune inflammatory cells in the nervous system, and it was not acting as a source of salicylate or as an adrenocortical stimulator.
Thymus Dependency of Host Resistance to Giardia Muris Infection: Studies in Nude Mice
Authors: Stevens David P. , Frank Dorothy M. , Mahmoud Adel A. F.
Published: December 2022

Infection of normal mice by the intestinal protozoan Giardia muris is self-limited and is followed by resistance to subsequent reinfection (1, 2). Similar observations have been made in G. lamblia infection in limited studies in human volunteers (3). The nature and mechanism of this parasite elimination are, however, unclear. Immune mechanisms may be suspected in human infection with G. lamblia because of the high prevalence of chronic giardiasis in persons with variable immune deficiency syndrome (4). Congenitally hypothymic (nude, nu/nu) mice provide a useful model to test the contribution of thymus-dependent immune mechanisms in resolution of this protozoan infection. We have previously described the natural history of G. muris infection in mice (1). The infection can be measured by counting trophozoites in small intestine and cysts in feces; peak fecal cyst excretion occurs 1 to 2 weeks after oral inoculation of cysts in CF-1 outbred mice and in A/J and BALB/c inbred strains followed consistently by resolution of infection in 4 to 7 weeks (1, 2).
T Lymphocyte-Mediated Cytolysis: Dissociation of the Binding and Lytic Mechanisms of the Effector Cell
Authors: Fishelson Zvi , Berke Gideon
Published: December 2022

To determine functional relationships between the cytotoxic T lymphocyte (CTL) receptor for target binding and the lytic mechanism, we have studied the reaction between two immunized CTL populations (AαB and BαA), both at the population and the single-cell level. When studied at the population level, the reaction of AαB with BαA (bidirectional system) resulted in formation of AαB/BαA conjugates and bidirectional cytolysis. However, when the viability of cells in individual AαB/BαA conjugates was analyzed, unidirectional instead of bidirectional lysis occurred. These results indicate that under conditions that are conducive to lysis, binding of a potentially lytic cell to its target does not necessarily result in target lysis. Short heat treatment of CTL (44°C, 10 min) totally abolished their lytic activity, without affecting their capacity to bind specifically, thus dissociating the binding from the lytic activity of the CTL. The cytolytic activity is probably associated with, or triggered by the CTL-binding unit. The binding unit, on the other hand, appears to be a functional receptor of the CTL, which is involved in but not sufficient to bring about lysis.
Separation of Helper and Suppressor T Lymphocytes
Authors: Tse Harley Y. , Dutton Richard W.
Published: December 2022

Using a Ficoll velocity sedimentation gradient, we provide evidence to show that stimulatory and inhibitory activities induced in mixed lymphocyte culture belong to two distinct subpopulations of T cells. Slow- to medium-sedimenting, nonproliferating cells enhance the humoral response of normal cells to SRBC whereas fast-sedimenting cells inhibit that response. Cytotoxic lymphocytes are found in the same fractions as suppressor cells but appear to be differentiable from the latter in terms of maturation kinetics and specificity
Effects of Vitamin B6 Deficiency on Thymic Epithelial Cells and T Lymphocyte Differentiation
Authors: Willis-Carr J. I. , St. Pierre R. L.
Published: December 2022

Dietary vitamin B6 (pyridoxine) deficiency in young Lewis rats results in a reduction of T lymphocyte numbers and defects of cellular immunocompetence. In vitro studies of thymic epithelial (TE) cells, responsible for inducing T lymphocyte differentiation, revealed that maintenance on a vitamin B6 deficient diet for 2 weeks resulted in a severe defect in TE cell function. When the deficient animals were returned to a normal diet, TE cell function was restored. Exposure of lymphoid precursors from neonatally thymectomized or vitamin B6-deficient donors to normal TE monolayers resulted in their conversion to functional T lymphocytes, as measured by their response in MLR and to mitogens. However, TE monolayers from vitamin B6-deficient animals were unable to effect such a maturation of T lymphocytes. Therefore, it is suggested that the defect in cellular immunocompetence following this dietary deficiency is due, at least in part, to the inability of TE cells to effect the differentiation of T lymphocyte precursors to functional T lymphocytes. The dietary deficiency does not, however, impair lymphoid precursors, which can be stimulated to further differentiation by exposure to normal TE cell monolayers.
Characterization of a Soluble Factor that Specifically Suppresses the in Vitro Generation of Cells Cytotoxic for Syngeneic Tumor Cells in Mice
Authors: Takei Fumio , Levy Julia G. , Kilburn Douglas G.
Published: December 2022

A tumor-specific soluble factor found in extracts of thymocytes from mice bearing small P815 tumors has been demonstrated. This factor is capable of significantly suppressing the in vitro generation of syngeneic cells cytotoxic for P815 targets if it is added to culture vessels within the first 30 hr of culture. The suppressive factor eluted from Sephadex G-100 after hemoglobin and was estimated to have a m.w. in the range of 40 to 60,000. Preparative isoelectric focusing of thymic extracts established that the suppressive material has an isoelectric point in the range of pH 4.6 to 4.9. The suppressive activity of extracts could be removed by passage of the material through immunoadsorbent columns prepared from membrane proteins of P815 cells but not by analogous columns prepared by using L1210 membrane proteins. The suppressive material was not removed by its passage through immunoadsorbent columns containing anti-mouse immunoglobulin.
Immune Responses During Human Schistosomiasis Mansoni
Authors: Colley Daniel G. , Lewis Fred A. , Goodgame Richard W.
Published: December 2022

Human peripheral blood lymphocytes from patients with chronic Schistosoma mansoni infection were exposed to concanavalin A (Con A), soluble schistosome egg antigenic preparation (SEA), or soluble adult worm antigenic preparation (SWAP). They were then evaluated for their ability to suppress the phytohemagglutinin response of autologous cells. Significant suppression was reliably obtained by Con A pretreatment of the cells of 15 of 17 patients (88%). Pre-exposure of patient's cells to SEA and SWAP in medium supplemented with normal human serum (NHS) resulted in significant suppression being expressed by 36% and 39% of the patients, respectively. The ability to express suppressor activity in these circumstances did not appear to correlate with the intensity of the patient's S. mansoni infection, or the clinical state of the patient's disease. The capacity to generate schistosomal antigen-induced suppressor activity increased sharply during the second decade of life, in general, correlating with increased duration of infection. Preliminary studies have indicated that the ability to generate schistosome antigen-induced suppressor activity was greatly increased when the cells were exposed to the antigens in the presence of “suppressive” sera from a patient with chronic S. mansoni infection rather than NHS. This information suggests a synergistic relationship, involving antigenic exposure of both the cells and sera of certain chronic patients, which assists in the induction of suppressor activity. The immunoregulatory responses observed could be important in the establishment of a stable chronic infection state by modulating the extent of egg-induced granuloma formation and preventing rejection of the adult worm.
A Two-Step Centrifugation Procedure for the Purification of Sheep Erythrocyte Antigen-Binding Cells
Authors: Kenny James J. , Merrill Jean E. , Ashman Robert F.
Published: December 2022

A two-step centrifugation procedure has been developed to isolate greater quantities of highly purified sheep erythrocyte antigen-binding cells (ABC) than previously possible. The first step involves partially separating sheep erythrocyte rosettes from unrosetted lymphocytes by their difference in buoyant density on Ficoll-Hypaque. Subsequent passage through a linear 5 to 10% Ficoll gradient produces further purification of rosettes by sedimentation velocity. Approximately 4.5 × 106 ABC can be obtained at 50 to 100% purity from 109 immune spleen cells (5 days post-immunization) and 1 × 105 ABC at 20 to 40% purity from 109 nonimmune spleen cells. The purified ABC from 5-day immune animals are 80 to 90% B cells and 10 to 20% T cells, and represent between 30 and 40% of the original ABC in the spleen cell population. Less than 0.2% of the purified ABC are plaque-forming cells (PFC) and less than 2% have intracellular immunoglobulin (Ig) or J chain. The quantities of ABC obtained are sufficient for investigating biochemical parameters of antigen-induced lymphocyte activation and for direct analysis of the surface isotypes found on antigen-binding cells after immunization.
Increase of T Lymphocyte Self-Reactivity in Aging Inbred Rats: In Vitro Studies with a Model of Experimental Autoimmune Orchitis
Authors: Kyewski Bruno , Wekerle Hartmut
Published: December 2022

To study the self-reactivity of rat lymphocytes as a function of age we applied an in vitro correlate of the experimental autoimmune orchitis (EAO). Previous analyses indicated that in this in vitro model, T lymphocytes react specifically against autoantigens when cocultured with syngeneic testis cells. The EAO response shows tissue specificity and is determined by the MHC. The self-reaction is measured in a cytostasis microassay, which is based on estimating growth inhibition of testis cell-derived monolayer formation in a terminal 51Cr uptake assay. We compared the self-reactivity of individual rats of varying ages (3 to 26 months) by testing their in vitro EAO responsiveness. In parallel, their reactivity to alloantigens and a polyclonal T lymphocyte activator (Con A) was monitored. We found a decrease in the allo- and the mitogen responsiveness in aged animals (from 20 months on) compared to young controls (3 months). The self-reactivity, in contrast, was in all cases increased. The increased EAO response was found not to be due to age-dependent alteration of the relevant autoantigens nor to changed functions of accessory non-T cells. The enhanced autoimmune reactivity was rather a property of the T cell compartment. We believe that these results indicate an age-dependent loss of T lymphocyte self-tolerance, which may play an active role in the pathogenesis of autoimmune diseases in the aging organism.
The Central Nervous System-Associated Immune Response to Parainfluenza Type I Virus in Mice
Authors: Gerhard Walter , Iwasaki Yuzo , Koprowski Hilary
Published: December 2022

The immune response in the cerebrospinal fluid (CSF) and serum of BALB/c mice was compared after intracerebral (i.c.) inoculation with inactivated parainfluenza type 1 virus. The antiviral antibody response in CSF peaked approximately 11 days after primary i.c. inoculation coinciding with or even slightly preceding the response in the serum. Prior extracerebral priming of the mice by the intranasal or i.v. route did not alter the kinetics of the response in CSF. However, the antibody response in CSF after i.c. inoculation was accelerated if the mice were primed previously by the i.c. route. In all instances, CSF and serum differed markedly with regard to the isotype composition, which was characterized by a 20- to 80-fold increase in IgA over IgG1 and IgG2 in CSF.

Taken together, the results prove that part of the antiviral antibodies in CSF are locally produced. In addition, the results indicate that after primary i.c. inoculation with virus, the CNS acquired immunocompetence with regard to the secondary anti-parainfluenza response.
Studies on the Mitogen Responses of Germfree Allogeneic Chimeras
Authors: Mattingly Jerome A. , Webb Phyllis M.
Published: December 2022

Germfree allogeneic bone marrow chimeras (ABMC) were produced by the i.v. injection of approximately 107 bone marrow cells from germfree DBA/2 mice into lethally irradiated germfree C3H mice. In the germfree state, the short-term ABMC showed no histologic signs of graft-vs-host reactions (GVHR), yet splenic lymphocytes were unable to respond to PHA, Con A, or SRBC. Attempts to remove nonspecific suppressor cells by the glass adherence technique failed to improve responsiveness. Attempts to improve responsiveness by the implantation of a DBA/2 thymus under the host kidney capsule also resulted in failure. However, when the donor thymus was enclosed in a cell-impermeable chamber to eliminate a GVH reaction, responsiveness to Con A was restored. The PHA and SRBC responses were unaffected by this treatment. Daily injections of thymosin caused both an increased Con A response and increased numbers of PFC, although the PHA response was again unaffected. Thus, soluble substances from thymic tissue can be used to overcome partially the histocompatibility barrier present in the ABMC that affects at least two different functional cell populations.
Characterization of Murine Colony-Forming B Cells
Authors: Kincade Paul W. , Paige Christopher J. , E. Parkhouse R. Michael , Lee Grace
Published: December 2022

With appropriate culture conditions, numbers of proliferating foci are a linear function of the number of B cells placed in mitogen-stimulated semisolid cultures, and colony formation is not obviously suppressed or enhanced by T cells. This made it possible to determine the fraction of Ig+ B cells in different tissues and stages of development which was capable of colony formation. No evidence was obtained that these functional cells were enriched among either mature or immature B cell populations. Cytolysis with A.TH anti-A.TL serum and C before culture was used to study expression of Ia antigens on colony-forming cells. By this criterion, multipotential stem cells, granulocyte-macrophage progenitors, and fetal colony-forming B cells were Ia negative, whereas all clonable B cells in adult tissues were Ia positive. Colony formation by adult lymph node cells was inhibited by an average of 79% by the addition of rabbit anti-mouse IgD to the cultures, and extremely small quantities of antiserum were required. Adult spleen and bone marrow contained a higher percentage of antiserum-resistant and presumably δ- B cells, and clonable B cells in fetal tissues were not significantly inhibited. An additional subpopulation of late appearing B cells whose proliferation was resistant to anti-Ig antibodies was identified with a particular set of culture conditions. Colony-forming cells were also heterogeneous in their resistance to preincubation with anti-immunoglobulin antibodies. Under conditions that did not significantly affect adult splenic B cells, clonable cells in fetal and neonatal tissues were substantially inactivated. It appears that colony-forming B cells comprise an equivalent proportion of the B cells in different sites and stages of development and include cells that differ in maturity by the criteria employed here. However, they do not seem to be representative of B cells as a whole, and when considered in relationship to the defect in CBA/N mice, the possibility emerges that the cloning technique preferentially detects a lineage of functionally specialized B cells.
Complement (C3)-Activated Phagocytosis by Lung Macrophages
Authors: Shurin Susan B. , Stossel Thomas P.
Published: December 2022

We have investigated the interaction between rabbit lung macrophages and Escherichia coli lipopolysaccharide-coated oil droplets opsonized with a fragment of C3, and of albumin-coated oil droplets opsonized with anti-albumin IgG.

We also examined in detail C3-dependent, IgG-activated, and nonspecific phagocytosis by trypsinized rabbit lung macrophages. We found that: 1) there was no basal ingestion of the LPS particles by macrophages, and reaction of particles with heated serum or anti-LPS antibody failed to elicit ingestion. Only fresh serum (deposition of C3) caused LPS particles to be ingested by macrophages. C3 alone, therefore, is the activator of phagocytosis in this system. 2) The ingestion of C3-coated particles occurred at a rapid constant rate for 2 min, followed by a slower constant rate; the ingestion of IgG-coated particles occurred at a single constant rate. 3) The initial rapid phase of C3-mediated ingestion was dependent upon the presence of divalent cations in the incubation medium; the secondary rate of ingestion of C3-coated particles and the ingestion of IgG-coated particles were not dependent on divalent cations. 4) Heated serum, which contains enzymes that destroy opsonically active C3 on particles, diminished the ingestibility of C3-coated particles, but did not alter the biphasic kinetics of the ingestion mechanism. Although heated serum decreased the ingestibility of C3-coated particles by rabbit exudate polymorphonuclear leukocytes more rapidly than by macrophages, the ultimate loss of ingestibility was equivalent for both cell types. 5) Trypsin rapidly diminished, but did not abolish, C3-activated phagocytosis without affecting IgG-activated or nonspecific ingestion. The principal effect of trypsin was to abolish the initial rapid phase of ingestion. 6) After trypsinization, the macrophages could recover trypsin-sensitive functions. Recovery was dependent upon: a) time, 4 hr being required for complete recovery; b) temperature, with recovery occurring at 37°C but not at 0°C; c) exogenous serum protein (serum or albumin); and d) endogenous protein synthesis (cycloheximide inhibited recovery). The role of serum protein was independent of its lipid-carrying capacity. Drugs thought to influence secretion by acting on cytoplasmic microtubules (colchicine) or which inhibit secretion of a macrophage protease (dexamethasone) had no effect on recovery.

C3-mediated ingestion and IgG-mediated ingestion by lung macrophages differ in their kinetic patterns. Trypsin treatment of macrophages and removal of divalent cations from the medium affect C3-mediated ingestion primarily by altering its kinetics. They exert their effects during an initial rapid phase of ingestion which is not seen in IgG-mediated ingestion. The effect of trypsin on macrophages is reversible with time under appropriate conditions.
Breast Milk IgA Binds to Jejunal Epithelium in Suckling Rats
Authors: Nagura Hiroshi , Nakane Paul K. , Brown William R.
Published: December 2022

We conducted peroxidase-labeled antibody immunocytochemical studies on the gastrointestinal tracts of neonatal rats to determine the disposition of IgA ingested in maternal milk.

From the onset of suckling to sometime between the 15th and 21st days of life, IgA and the secretory component (SC) were localized on the luminal surfaces of villi in the proximal one-third of the small intestine. At the ultrastructural level, these components of secretory IgA were associated with the plasma membranes of the upper one-third to one-half of microvilli. The IgA could not be removed by vigorous washing or trypsin treatment; it was not internalized or transported through the enterocytes to intercellular spaces; it could not be attributed to endogenous sources within the neonates. By contrast with IgA, ingested IgG was bound to the lower portions of microvilli and intervening apical plasma membranes of jejunal enterocytes, and was internalized and transported through the cells in membranous vesicles.

In the distal small intestine, neither IgA nor IgG was bound to the epithelial surface, but both immunoglobulins were found in cytoplasmic vacuoles that did not fuse with lateral cell membranes or discharge their contents into intercellular spaces.

We conclude that villus enterocytes of neonatal rat jejunum have specific binding sites for maternal secretory IgA that are distinct from the sites that bind IgG. IgG binding is involved in transepithelial translocation of immunoglobulin into the circulation, but bound IgA remains on the epithelial surfaces. In the distal small intestine, IgA and IgG are taken nonspecifically into villus epithelial cells but are not transported through the cells intact.
A Mechanism for the Suppression of Graft-vs-Host Disease with Endotoxin
Authors: Thomson Philip D. , Rampy P. A. , Jutila John W.
Published: December 2022

It was shown that as few as 5 × 106 adherent spleen cells from CBA mice pretreated with endotoxin would suppress the GVH reactivity of 2 × 107 whole normal spleen cells from CBA mice when given to BALB/c neonates. This suppressive effect was also observed after the incubation of these two spleen cell populations in vitro for 2 hr. This adherent cell population of mice treated with endotoxin was characterized, and cell-cell contact was observed between macrophages and lymphocytes after in vitro incubation. Although no cell product was detected in the in vitro incubation environment, which impaired the GVH reactivity of 2 × 107 CBA whole normal spleen cells, as little as 0.1 ml of serum from endotoxin-treated mice, rich in IgM antibody, suppressed the GVH reactivity of 2 × 107 CBA whole normal spleen cells when given to BALB/c neonates. Endotoxin treatment of CBA mice also prevented normal rejection of allogenic skin and tumors. A mechanism is proposed in which adherent spleen cells and humoral factors from mice treated with endotoxin interact with normal spleen cells from CBA mice to abrogate the GVH disease in BALB/c neonates.
Purification of Human Monocytes on Microexudatecoated Surfaces
Authors: Ackerman Samuel K. , Douglas Steven D.
Published: December 2022

Human blood monocytes, but not other Ficoll-Hypaque cells, adhere to plastic surfaces from which confluent BHK cells have been removed. EDTA (3 mM) rapidly and completely removes monocytes, providing a simple technique for preparation of human monocytes in suspension. The method should be valuable for studies of monocyte function where monocyte monolayers are not suitable.
Changes in Fluorescence Polarization of a Membrane Probe during Lymphocyte-Target Cell Interaction
Authors: Berke Gideon , Tzur Ruth , Inbar Michael
Published: December 2022

Interaction of exposed membrane-lipid regions after mixing of immune peritoneal exudate T lymphocytes (PEL) and target cells (TC) was studied by monitoring the degree of fluorescence polarization (P) of 1,6-diphenyl 1,3,5-hexatriene (DPH), a lipophilic probe, which can be transferred upon contact of lipid phases. Since the P of DPH-labeled PEL and labeled TC differed significantly, detection of DPH translocation between labeled and nonlabeled cells was possible. A decrease in P was observed after interaction of DPH-labeled PEL and nonlabeled TC. Conversely, an increase in P was detected after nonlabeled PEL were allowed to react with DPH-labeled TC. These changes in P were evident when TC were reacted with specific PEL. However, substantial changes were also monitored with PEL immunized against third-party target cells. No significant changes in P were obtained when DPH-labeled TC were reacted with normal or immune lymph node cells or thymocytes, or with anti-TC antibody. These findings suggest that nonspecific collision of exposed membrane lipid regions occurs during immune PEL-TC interaction. We propose that binding of cytotoxic lymphocytes and TC is preceded by an unstable and nonspecific hydrophobic interaction of cells, which facilitates specific and stable binding. In support of this proposal is the finding that changes in the composition of membrane lipid constituents prevent binding of PEL and TC.
Senile Cardiac Amyloid: Demonstration of a Unique Fibril Protein in Tissue Sections
Authors: Cornwell Gibbons G. , Natvig Jacob B. , Westermark Per , Husby Gunnar
Published: December 2022

Antisera were raised against degraded amyloid fibrils isolated from the heart of a patient with senile cardiac amyloidosis (SCA), and from a medullary carcinoma of the thyroid (MCT). The antisera were absorbed and used in indirect immunofluorescence to identify an amyloid fibril protein (ASCA) in heart tissue from patients with senile cardiac amyloidosis and to identify the amyloid fibril protein (AMCT) found in association with medullary carcinomas of the thyroid. Absorbed anti-ASCA antiserum did not react with normal tissue such as heart, liver, spleen, and striated muscle, or with amyloid tissue known to contain amyloid fibril proteins AA, AλI, AλIV, AλV, AMCT or with pancreatic tissue containing islet amyloid deposits. The reactions with senile amyloid heart tissue could be blocked completely by degraded amyloid fibrils extracted from senile amyloid heart tissue or by amyloid fibril protein ASCA isolated from such fibrils. The anti-AMCT antiserum showed a similar specific reaction restricted to amyloid associated with MCT. In addition, antisera specific for amyloid fibril proteins AA, AλI, AλIV, and AλV failed to react with senile cardiac amyloid, pancreatic islet amyloid, or medullary thyroid amyloid.