bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies of the Molecular Mechanisms of C3b Inactivation and a Simplified Assay of β1H and the C3b Inactivator (C3bINA)
Authors: Gaither Thelma A. , Hammer Carl H. , Frank Michael M.
Published: December 2022

A sensitive radio assay was developed to evaluate and quantitate the function of the control proteins important in the cleavage of cell-bound C3b and in the release of the subfragment C3c. In addition, the effects of the control proteins on C3b functional hemolytic activity and on C3b immune adherence reactivity were measured. The cellular complement intermediate EAC43b was prepared with highly purified radiolabeled C3. The effects of incubation with β1H and the C3b inactivator were followed over a wide range of protein concentrations, and the kinetics of the interaction was measured. Incubation of EAC43b* with β1H led to some decrease in immune adherence activity but no loss in C3b functional hemolytic activity and no change in the integrity of the α- or β-chains. Addition of C3b inactivator to the membrane-bound β1H-C3b complex led to a single cleavage of the C3b α-chain without release of the C3c fragment from the cellular site. This led to complete loss of C3b functional hemolytic activity. The α-chain cleavage led to loss but not complete disappearance of immune adherence reactivity. The action of both β1H and the C3b inactivator on cell-bound C3b led to the appearance of a trypsin-sensitive bond within the α-chain. Addition of trypsin led to a second cleavage of the α-chain and the release of the radiolabeled C3c fragment. In kinetic studies the appearance of the trypsin-sensitive bond was shown to parallel the loss of C3b functional hemolytic activity. Kinetic studies demonstrated that both plasma and serum contain all of the ingredients for a C3b-cleaving system. By utilizing this sensitive radio-release assay, the functional titers of C3b inactivator in the serum of 15 normal individuals were found to be 11,310 ± 666 S.E. The mean β1H titer for 12 normal individuals was 20,600 ± 873. This assay can be used to quantitate the level of the trypsin-like enzyme as well. The assay provides a simple method to quantitate and evaluate the function of the C3b control proteins.
Qa-1-Associated Antigens
Authors: Kastner Daniel L. , Rich Robert R. , Shen Fung-Win
Published: December 2022

In this report we present evidence for the generation of H-2-nonrestricted cytotoxic T lymphocytes (CTL) specific for determinants encoded in the Qa-1 region of the 17th chromosome. B10.BR (Qa-1a) CTL primed in vivo and restimulated in vitro with H-2-identical AKR, C3H, or CBA (Qa-1b) splenocytes lysend Qa-1b targets, irrespective of their H-2 haplotypes. Immunizations in the reverse direction produced H-2-nonrestricted CTL that lysed Qa-1a but not Qa-1b targets. Mapping experiments with target cells from B6 congenic mice confirmed that the locus controlling these reactions lies in the Qa-1 region. Although it has been difficult to raise antisera against Qa-1b gene products, our cytotoxic data argue that the recognition of the products of the Qa-1 region is bidirectional.

Determinants encoded in the Qa-1 region, detected serologically or by CTL, were found on both T and B cell blasts. We also found that an antiserum against Qa-1a gene products specifically blocked the cell-mediated killing of Qa-1a targets, thus suggesting that CTL and antibodies bind products of the same genetic locus. Whether Qa-1 is a single locus or a complex of serologically and CTL-defined genes, the nonrestricted nature of anti-Qa-1 CTL suggests important functional and structural similarities between Qa-1 and the murine major histocompatibility complex.
Demonstration of Mouse Serum IgD
Authors: Finkelman Fred D. , Woods Virgil L. , Berning Alice , Scher Irwin
Published: December 2022

Although the mouse would provide an excellent experimental model for the study of serum IgD function, previous investigations have failed to detect serum IgD in this species. We have developed an immunofluorescence inhibition assay that has allowed us to identify and quantitate mouse serum IgD. Mouse sera or serum fractions were assayed for their abilities to inhibit staining of mouse spleen cells with an allotype-specific fluorescein isothiocyanate-labeled rabbit antibody against mouse cell-surface IgD (FITC-RaMδa), as analyzed with a fluorescence-activated cell sorter. FITC-RaMδa stains surface IgD+ spleen cells of mouse strains that have surface(s) sIgD of the a allotype, such as BALB/c, but not strains that have surface IgD of the b allotype, such as C57BL/6 or C.B20, which have the C57BL/6 CH genome on a BALB/c background. The staining of BALB/c lymphocytes by FITC-RaMδa was inhibited by BALB/c serum, but not by C57BL/6 or C.B20 serum. The staining was also not inhibited by BALB/c sera that had been adsorbed with rabbit anti-mouse Ig or a mouse hybridoma protein anti-mouse δ, or by BALB/c IgG, IgM, or IgA plasmacytoma proteins. These data strongly suggest that mice have IgD in their serum. Mouse serum IgD is probably secreted rather than shed from B cells, since amounts of serum IgD and splenic IgD in the same mice did not correlate with each other and serum IgD and shed sIgD had different density profiles.
Studies of Congenitally Immunologic Mutant New Zealand Mice
Authors: Ohsugi Yoshiyuki , Gershwin M. Eric
Published: December 2022

There is a growing data base suggesting the existence of a primary B cell defect in New Zealand mice. To identify and characterize this possibility further, attention has been focused on developmental aspects of B lymphocyte clone formation in congenitally athymic (nude), hereditarily asplenic (Dh/+), conventionally housed, and germfree New Zealand Black (NZB) mice. Lipopolysaccharide-induced and background B lymphocyte cloning of fetal liver, spleen, lymph node, bone marrow, and thymus in semisolid agar was compared in NZB mice to age-matched NZW, BALB/c, C57BL/6, C3H/He, and DBA/2N mice. The number of splenic B cell colony-forming cells and the peak day for colony formation were similar for BALB/c, C57BL/6, C3H/He, and DBA/2N mice; adult values were reached by 14 to 30 days and were approximately 400/2.5 × 104 cells. A slightly higher value, with similar age kinetics, was observed in NZW mice. In contrast, NZB mice have statistically higher values compared to other strains from birth through 2 months of age; peak adult values were approximately 860/2.5 × 104 splenic cells. Moreover, with age, the number of splenic colony-forming cells rapidly diminished and was significantly reduced after 6 months. Similar data were obtained when B lymphocyte clones were compared by using bone marrow and lymph node. Further, the number of B lymphocyte clones of 17-day-old NZB fetal liver was significantly higher than in control mice. Finally, of particular interest, the number of B lymphocyte clones in NZB Dh/+ mice was similar to that +/+ mice and the number of B lymphocyte clones in NZB nude mice was similar to that in nude/+ littermates, suggesting that this B cell defect is thymus independent and unrelated to antigen-nonspecific suppressor function.
A Monoclonal Antibody with Selective Reactivity with Functionally Mature Human Thymocytes and All Peripheral Human T Cells
Authors: Reinherz Ellis L. , Kung Patrick C. , Goldstein Gideon , Schlossman Stuart F.
Published: December 2022

A monoclonal antibody directed at a determinant on human peripheral blood T cells was produced and characterized. This hybridoma antibody, termed OKT1, was reactive by indirect immunofluorescence with the entire human peripheral blood T cell population and a subset of human thymocytes. In contrast, OKT1 was unreactive with normal B cells, Null cells, macrophages, and ≥90% of human thymocytes. These findings suggested that OKT1 defines a mature T cell differentiation antigen. In support of this notion was the observation that T cell acute lymphoblastic leukemia cells were nonreactive with OKT1, whereas T cell chronic lymphocytic leukemia cells were reactive. Concomitant functional studies on FACS-separated lymphocytes showed that the T cell proliferative responses to mitogens and soluble and cell surface antigens were contained in the OKT1+ population. Fractionation of peripheral blood T cells into strongly and weakly reactive OKT1+ subgroups uncovered no functional T cell heterogeneity. In addition, when the thymocyte population was separated into OKT1+ and OKT1- subsets, only the OKT1+ thymocytes were MLC responsive. However, unlike peripheral T cells, neither the OKT1+ or OKT1- thymocytes proliferated to the mitogens PHA and Con A. Thus, OKT1+ thymocytes are functionally distinct from OKT1+ peripheral blood T cells. These studies show that a hybridoma antibody can be produced that detects a human differentiation antigen that appears during late intrathymic T cell ontogeny and persists on peripheral T cells.
Stimulators and Inhibitors of Lymphocyte DNA Synthesis in Supernatants from Human Lymphoid Cell Lines
Authors: Vesole David H. , Goust Jean-Michel , Fett James W. , Fudenberg H. Hugh
Published: December 2022

Some T and B lymphoid cell lines (LCL) were found to secrete into their supernatants a substance able to stimulate lymphocyte proliferation. This substance produced an increase in [3H]thymidine uptake by mononuclear cells when added to unstimulated cultures (mitogenic effect) or when added to cultures stimulated with phytohemagglutinin (PHA) or pokeweed mitogen (PWM) (potentiating effect). When complete supernatants were used, the potentiating effect was sometimes masked by an inhibitor of DNA synthesis. Fractionation on Sephadex G-100 separated these two activities. The stimulatory substance eluted at a m.w. range of 15,000 to 30,000, and the inhibitor eluted with the albumin peak. B cells with or without monocytes were the most sensitive to the mitogenic effect, whereas T cells were unaffected. Responses to PHA and PWM were potentiated when T cells were present, but the maximum effect was observed when the proportion of T cells was less than 50%. The stimulatory material may be similar to lymphocyte mitogenic factor and may function as a T cell-replacing factor in B cell stimulation.
Demonstration of Circulating Immune Complexes in Sjögren's Syndrome
Authors: Lawley Thomas J. , Moutsopoulos Haralampos M. , Katz Stephen I. , Theofilopoulos Argyrios N. , Chused Thomas M. , Frank Michael M.
Published: December 2022

The sera of patients with Sjögren's syndrome have been examined for circulating immune complexes with the 125I-C1q binding assay and the Raji cell radioimmunoassay. Elevated 125I-C1q binding was found in the sera of 47 of 55 patients (85%) and a positive Raji cell assay was found in the sera of 17 of 20 patients (85%). The two assay showed concordance of 90% in the detection of circulating immune complexes. The amount of immune complexes as detected by the Raji cell assay was not correlated with the titer of IgM or IgG rheumatoid factor. Interestingly, however, a positive association was found between the C1q-binding activity and the titer of IgM rheumatoid factor (Spearman rank correlation coefficient [rho = 0.551], p < 0.0005) although there was no association between C1q-binding activity and the amount of IgG rheumatoid factor. In order to investigate further the positive association of C1q-binding activity and IgM rheumatoid factor, sera were treated with either 2-mercaptoethanol to dissociate 19S IgM RF or solid phase protein A to absorb IgG and were then analyzed for C1q-binding activity and IgM rheumatoid factor. Pretreatment of the sera with 2-mercaptoethanol resulted in complete elimination of IgM rheumatoid factor activity but only slight to moderate reductions in C1q-binding activity. Partially purified IgM rheumatoid factor when added to normal human serum did not result in increased C1q-binding activity. All C1q-binding activity could be removed from Sjögren's syndrome sera by absorption with solid phase protein A, which at the same time caused slight to moderate decreases in the IgM rheumatoid factor titer. These findings indicate that a high percentage of patients with Sjögren's syndrome have circulating immune complexes most of which are distinct from 19S IgM and IgG rheumatoid factor.
The Enzymatic Nature of Human C1r̄: A Subcomponent of the First Component of Complement
Authors: Andrews Judith M. , Baillie Richard D.
Published: December 2022

The esterase activity of the Clr̄ subcomponent of the first component of complement has been investigated. Clr̄ was found to hydrolyze two amino acid methyl esters; N-acetyl-L-arginine methyl ester and N-acetyl-glycyl-L-lysine methyl ester, and two amino acid p-nitro-phenyl esters, N-carbobenzyloxy-L-tyrosine-p-nitro-phenyl ester and Nα-carbobenzyloxy-L-lysine-p-nitrophenyl ester. A detailed kinetic analysis of the hydrolysis of N-Z-L-Tyr-ONp by Clr̄ revealed that the enzymatic activity per microgram of protein decreased as the Clr̄ concentration was increased. the loss of activity suggested that above 0.5 µM Clr̄ was undergoing aggregation with a loss of active sites. Similarly, when Clr̄ was titrated with the active site titrant p-nitrophenyl-p-guanidinobenzoate the number of titratable sites per milligram of protein decreased with increasing protein concentration. The hydrolysis of N-Z-L-Tyr-ONp by Clr̄ was inhibited by several synthetic inhibitors including phenylmethanesulfonylfluoride, p-amidinophenylmeth-anesulfonylfluoride, diisopropylfluorophosphate, and p-tosyl-L-lysine-chloromethyl ketone. However, the peptide esterase inhibitors Trasylol, hirudin, leupeptin, and Cl̄ esterase inhibitor had no effect on the esterase activity of Clr̄.
Distinct Effects of Thymic Epithelial Culture Supernatants on T Cell Properties of Mouse Thymocytes Separated by the Use of Peanut Agglutinin
Authors: Kruisbeek Ada M. , Astaldi Giulia C. B.
Published: December 2022

Supernatants from thymic epithelial cultures (TES), a putative analogue of thymic humoral function, are shown to induce strong cytolytic T lymphocyte (CTL) responses when added to primary mixed lymphocyte cultures (MLC) with thymocytes as responder cells. No enhancing effects of TES are observed with spleen cells or hydrocortisone-resistant thymocytes. These effects of TES on functional T cell parameters are accompanied by a reduction in part of the thymocytes in Thy 1 antigen density and sensitivity to hydrocortisone (HC). Inasmuch as immunocompetent T cells are found only among the HC-resistant thymocytes expressing a low Thy-1 antigen density, these findings suggest a TES-induced maturation process of thymocytes.

In addition, we attempted to answer the question of whether the enhancing effects of TES on T cell-proliferative capacity and T cell killer function of thymocytes are due to an effect on previously unresponsive immature T cells or merely to extra stimulation of already responsive cells. Using the peanut agglutinin (PNA)-agglutination technique as a reversible probe, we could now demonstrate that TES affects the T cell-proliferative and CTL responses of the PNA-agglutinating thymocytes only. These findings support the concept that TES induces maturation of immature thymocytes, inasmuch as the PNA-agglutinating cells represent the immunoincompetent cells which are rich in Thy 1 and poor in H-2 antigens and HC sensitive. The PNA-nonagglutinating thymocytes exhibited high reactivity in all the functional assays investigated (like HC-resistant thymocytes), and this could not be further enhanced by TES.

Together with the observation that supernatants from nonthymic epithelial cultures or from thymic lymphocyte cultures exhibit no effects on any of the abovementioned parameters, these findings suggest that TES represents a relevant in vitro model for studying thymic humoral function.
Augmentation of Antigen-Stimulated Histamine Release from Human Basophils by Serum-Treated Zymosan Particles
Authors: Thomas Larry L. , Findlay Steven R. , Lichtenstein Lawrence M.
Published: December 2022

It was observed previously that serum-treated zymosan particles (Zx) augmented antigen and anti-IgE stimulated histamine release. With most of the enhancement attributed to an increased rate of release, this suggested that Zx was active only during the course of IgE-mediated release. This association between IgE-mediated histamine release and responsiveness to Zx was examined further in the present report. Addition of Zx at various time intervals after release had been initiated indicated that the basophil responsiveness to Zx was limited in duration; maximum responsiveness to Zx correlated closely with the period in which the rate of IgE-mediated histamine release was maximum. The time-dependent decline in sensitivity to Zx paralleled the kinetics for desensitization to antigen. Addition of Zx failed to cause release from basophils desensitized in vitro or from basophils of a donor who failed to release histamine upon challenge with anti-IgE. In contrast to the enhancement of IgE-mediated release, Zx did not augment histamine release caused by C5a or the synthetic peptide f-Met-Leu-Phe. It is concluded that an obligatory link exists between ongoing IgE-mediated histamine release and enhancement by Zx.
Primary in Vitro Immunogenicity of Liposomal Model Membranes in Mouse Spleen Cell Cultures
Authors: Yasuda Tatsuji , Tadakuma Takushi , Pierce Carl W. , Kinsky Stephen C.
Published: December 2022

Neither 2,4-dinitrophenyl-6-N-aminocaproylphosphatidylethanolamine (DNP-Cap-PE) nor fluoresceinthiocarbamylphosphatidylethanolamine (F1-PE) induces hapten-specific plaque-forming cells (PFC) when incubated with suspensions of spleen cells from unimmunized C57BL/6J mice. However, PFC are produced after incorporation of these synthetic lipid antigens into liposomal model membranes. The in vitro response is characterized by the following: a) it is time and dose dependent; b) the frequency of IgM PFC exceeds IgG PFC; c) both nonadherent and adherent cells are required (2-mercaptoethanol can replace the requirement for adherent cells in some experiments); d) depletion of thymusderived cells by treatment with anti-ϑ antiserum plus complement does not diminish the response; e) spleen cells from nude BALB/c mice also produce PFC. Thus, the essential features of the in vivo immunogenicity of DNP-Cap-PE and F1-PE sensitized liposomes, which have been previously described, can be replicated in an in vitro cell culture system.
Studies on the Mechanism of T Cell-Mediated Lysis at the Single Effector Cell Level
Authors: Zagury Daniel , Bernard Jacky , Jeannesson Pierre , Thiernesse Noëlle , Cerottini Jean-Charles
Published: December 2022

A procedure has been previously developed to allow kinetic analysis of target cell lysis in individual conjugates formed between murine alloimmune peritoneal exudate lymphocytes (PEL) and relevant tumor cells in suspension. Under the conditions used in the present work, 60% of the conjugates consisted of one lymphocyte bound to one target cell, whereas the remaining were multicellular, i.e., contained one lymphocyte bound to either two (24%), three (12%), or four (4%) target cells. Both ultrastructural studies and micromanipulation experiments with individual multicellular conjugates indicated differences in the degree of target cell binding to the same PEL. In more than 80% of the multicellular conjugates, lysis of all conjugated target cells occurred within a 3-hr incubation period at 37°C. Kinetic analysis of target cell lysis, however, showed that the time required for target cell death was quite variable, both within the same multicellular conjugate and between different conjugates, ranging from a few minutes to 3 hr after conjugation. By comparing the elapsed time necessary for lysis of 50% of the target cells in conjugates containing one lymphocyte bound to three target cells, it could be estimated that, on the average, lysis of the first, second, and third target cells occurred after 30, 60, and 90 min, respectively.

The time required for lethal hit of each conjugated target cell was measured by adding EDTA to the incubation medium of individual multicellular conjugates at various time intervals. Evidence could be obtained that a CTL induced irreversible lesions in only one of the conjugated target cells at a time, i.e., lethal hits were given sequentially rather than simultaneously.
Glucocorticoid-Induced Inhibition of T Cell Growth Factor Production
Authors: Gillis Steven , Crabtree Gerald R. , Smith Kendall A.
Published: December 2022

Although it has been clearly established that glucocorticoids inhibit mitogen- or antigen-induced lymphocyte proliferation, the mechanism underlying this effect has remained ill-defined. Recently, it has become evident that T cell proliferation is mediated by a soluble T cell growth factor (TCGF) released by mitogen/antigen stimulated T cells. Therefore it seemed probable that the inhibitory effects of glucocorticoids were manifested either at the level of TCGF production or at the level of the activated T lymphocyte. We found that differentiated cytolytic T lymphocytes harvested from TCGF-dependent long-term culture were only mildly sensitive to inhibitory effects (25 to 30% inhibition) of glucocorticoids as measured by decreased cellular proliferation and the incorporation of tritiated thymidine. The degree of inhibition observed was most probably mediated through glucocorticoid receptors in that the half maximal inhibitory glucocorticoid concentration correlated with half-maximal glucocorticoid receptor saturation. In contrast, we found that mitogen-induced TCGF production and T cell proliferation were completely inhibited by pharmacologic concentrations of dexamethasone (10-6 M). Finally, the TCGF supplementation of mitogen-stimulated cultures treated with maximal inhibitory concentrations of dexamethasone resulted in complete amelioration of glucocorticoid suppression. These results indicate that a major mechanism of glucocorticoid-mediated immunosuppression may occur at the level of the TCGF-producing cell, resulting in the control of clonal expansion of activated T cells via inhibition of TCGF production.
Signal Requirements for T Lymphocyte Activation
Authors: Rosenstreich David L. , Mizel Steven B.
Published: December 2022

Purified guinea pig T lymphocytes cannot be induced to proliferate by plant lectins in vitro unless they are reconstituted with either macrophages or a macrophagederived soluble factor. The effects of phorbol myristic acetate (PMA) on the activation of this purified T lymphocyte population were studied. Although PMA by itself was nonmitogenic for guinea pig T cells, at very low concentrations (10-5 µg/ml) it enabled purified T cells to respond to the lectins, PHA or Con A. However, it could not induce primed T cells to respond to a soluble antigen in the absence of macrophages. On the basis of several criteria, PMA appeared to be acting independently of macrophages. Its effect was unrelated to the number of macrophages in a lymphocyte preparation and it did not increase the accessory capability of additional macrophages.

Analysis of the kinetics of the interaction between PMA, lectins, and T cells revealed that these compounds could be added to the T cells independently and in any order and still induce activation. However, maximal T cell proliferation required that PMA and lectin be added within the first 4 hr of culture. In addition, both agents were capable of exerting their effects after a brief (1 hr) exposure. The results of this study indicate that PMA can replace macrophages as a source of the second signal that is required to induce T cell proliferation in vitro. This agent may prove to be extremely valuable in the analysis of both the biochemical alterations involved in the process of T cell activation, and the mechanism by which macrophages induce these alterations.
Direct suppression of lymphocyte induction by the immunoregulatory human serum low density lipoprotein, LDL-In.
Authors: Fujii D K , Edgington T S
Published: December 2022

Preparations of LDL-In, an immunosuppressive lipoprotein subfraction, were analyzed for the capacity to directly suppress the response of human lymphocytes to the representative stimulant PHA vis-a-vis indirect mechanisms mediated by soluble factors or cell:cell interactions. Serum lipoprotein subfraction enriched in LDL-In induced a suppressed state in lymphocytes during 18-hr induction cultures. These lymphocytes, whether partially or completely suppressed, when added to fresh responder lymphocytes in the presence of PHA did not suppress the response of the responder lymphocytes. In contrast, the major low density lipoprotein (LDL) did not suppress lymphocytes at equivalent concentration in the induction culture, nor did LDL-exposed lymphocytes suppress responder lymphocytes. The supernatant medium from LDL-In-suppressed lymphocytes did not contain a newly synthesized or released suppressive factor. Finally, LDL-In-suppressed lymphocytes were not rescued by normal lymphocytes. Each of these observations, and previous evidence that adherent cells do not mediate the biologic effects of LDL-In, support the hypothesis that the biologic manifestations of LDL-In suppression of lymphocyte function result from a direct effect on the lymphocyte that is exposed to this lipoprotein, possibly via the previously demonstrated LDL-In receptor.
Human granulocyte-specific nuclear antigen(s). II. Detection of antigens in human proliferative syndromes.
Authors: Briggs R C , Forbes J T , Hnilica L S , Montiel M M , Thor D E
Published: December 2022

Antisera raised to dehistonized chromatin from isolated normal human granulocytes revealed the presence of chromatin-associated antigens specific for the human neutrophils that appear during late stages of myeloid cellular differentiation. Immunological specificity was demonstrated by C fixation, immunodiffusion, and immunocytochemical reactions. Chromatin prepared from both normal granulocytes and specimens of myeloid leukemia showed immunologic reactivity. Although the normal antigens were detected in a specimen of CML, the position of immunodiffusion precipitin lines was different from that obtained with normal granulocyte chromatin. In addition, chromatin prepared from the myeloid leukemic cell line HL-60 expressed only one of the three precipitin bands normally found in immunodiffusion. The immunocytochemical staining reaction was confined to the nucleus of mature neutrophils in normal peripheral blood smears. Greater than 90% of cells in peripheral blood specimens of CML showed positive immunocytochemical nuclear staining. In other types of leukaemia, the normal mature granulocyte reacted with antiserum, but the nonmyeloid leukemic cells in these specimens did not. The specificity of immunologic reactions described here suggests the usefulness of nuclear antigens as cell markers.
Allogeneic radiation chimeras respond to TNP-modified donor and host targets.
Authors: Lattime E C , Gershon H E , Stutman O
Published: December 2022

Tolerance to major histocompatibility antigens as well as the ability to mount a cytotoxic response to hapten-modified cells of bone marrow donor and host origin was studied in allogeneic radiation chimeras. Lethally irradiated (C57BL/6 X DBA/2)F1 hosts reconstituted with anti-Thy 1.2 + C-treated bone marrow from (C57BL/6 X CBA)F1 mice showed tolerance to the MHC antigens of the three parental strains as measured by MLC and CML assay. The chimeras responded normally to unrelated allogeneic cells. Chimeric animals generated a cytotoxic response to hapten-modified cells of both donor (CBA) and host (DBA/2) haplotypes, as well as to C57BL/6, demonstrating that tolerance to the hapten-presenting host haplotype is sufficient to allow a cytotoxic antihapten response, and that processing through a semiallogeneic host environment does not affect the ability to generate a response to hapten in conjunction with self-determinants. Chimeras failed to mount a cytotoxic response to hapten presented on nontolerated allogeneic spleen cells.
Mechanisms of recovery from viral infections: destruction of infected cells by neutrophils and complement.
Authors: Grewal A S , Rouse B T , Babiuk L A
Published: December 2022

Highly enriched populations of bovine neutrophils (PMN) were able to destroy herpesvirus-infected cells when in the presence of C. This mechanism of cytotoxicity was termed C-dependent neutrophil-mediated cytotoxicity (CDNC). To demonstrate CDNC required viable PMN, an active source of C, and a target cell expressing viral antigens. Noninfected cells were not susceptible to lysis. Several approaches were used to exclude the presence of antibody as an explanation for the cytotoxicity observed. In a comparison of the effectiveness of different cell types at mediating CDNC, PMN were more effective than macrophages, and lymphocytes were without activity. The results was discussed in terms of the possible in vivo significance of the neutrophil as a cell type capable of mediating recovery from infection, since if a mechanism similar to CDNC occurs in vivo, this could play a role in defense before the time when protective levels of antibody and immune cells are generated.
Neonatal susceptibility to MHV3 infection in mice. II. Role of natural effector marrow cells in transfer of resistance.
Authors: Tardieu M , Héry C , Dupuy J M
Published: December 2022

Protection of newborn mice against MHV3 infection requires the transfer of several cell populations originating from adult syngeneic donors: adherent spleen cells, T lymphocytes, and a third population present in the nonadherent spleen cell fraction, in peritoneal exudates, and in bone marrow cells (M cells). M cells were found to be sensitive to short-term incubation at 37 degrees C and to preincubation with anti-bone marrow antiserum, mitomycin C, puromycin, and aggregated Ig, the latter suggesting the presence of Fc receptors. They were resistant to silica particles but were sensitive to irradiation with x-rays as well as with 89Strontium. Nonadherent spleen cells, however, behaved differently from M cells toward x-irradiation since they were radio-resistant, suggesting that M cells are precursors that require further differentiation or division to participate in MHV3 resistance. Effector M cells responsible for MHV3 resistance display, therefore, some similarities with natural killing cells. They might belong to a group of effector cells operative in regulatory processes or anti-tumor surveillance but also may be defense mechanisms against infectious diseases.
Antibody gene linkage studies in (NZB X C58) recombinant-inbred lines.
Authors: Riblet R , Claflin L , Gibson D M , Mathieson B J , Weigert M
Published: December 2022

A set of recombinant inbred mouse strains has been constructed from the cross of NZB by C58. These strains provide new tools for the analysis of antibody heavy and light chain genes and NZB autoimmunity. Typing of heavy chain genes confirmed the allotype linkage of the dextran response locus Igh-Dex. One strain has fixed a recombinant chromosome carrying NZB allotype genes and the Dex+ variable region gene from C58. Two kappa-light chain variable region genes, Igk-Pc and Igk-Ef1, co-segregated with the Lyt-2 lymphocyte alloantigen locus. This confirms the tight linkage of these loci and decreases the maximum estimate of the recombination frequency between them to 1.7%.
Bactericidal activity of eosinophil peroxidase.
Authors: Jong E C , Henderson W R , Klebanoff S J
Published: December 2022

A partially purified preparation of guinea pig eosinophil peroxidase was found to be bactericidal when combined with H2O2 and either iodide, bromide, chloride, or thiocyanate ions. The EPO-H2O2-halide bactericidal system had an acid pH optimum and was inhibited by the proteins albumin and gelatin and by the hemeprotein inhibitors azide, cyanide, and aminotriazole. When the EPO concentration of the reaction mixture was lowered, the bactericidal effect at pH 7.0 was lost first with chloride, then with bromide, and finally with iodide as the halide. Activity with physiologic concentrations of chloride was favored by a relatively high EPO level, a decrease in pH below neutrality and an absence of extraneous protein. These findings are discussed in relation to the potential role of the peroxidase system in the intracellular and extracellular toxic reactions of eosinophils.
Specific enhancement of immune responses by BCG: isolation of extracellular DNA from supernatants of specifically stimulated BCG-primed lymphoid cells.
Authors: Alaba O
Published: December 2022

When lymphocytes obtained from W/Fu rats primed with BCG are cultured in the presence of PPD, they elaborate a factor that is capable of potentiating the specific in vitro generation of cytotoxic lymphocytes to syngeneic (C58NT)D lymphoma cells and to BN alloantigen. Purification of the factor, achieved by gel filtration on Sephadex G-100, was facilitated by using a serum-free culture condition and the removal of the specific stimulating antigen, PPD, after an initial incubation period. The factor isolated contains DNA by its absorption spectrum, resistance to trypsin and RNase, but complete susceptibility to DNAase, and by the presence of ethidium bromide-positive material in the purified sample. It displays a 260/280 nm absorption ratio of 1.6 and a m.w. estimate of 10,000 to 30,000. Electrophoresis of the purified factor on agarose gel yielded three ethidium bromide reactive bands. Data obtained following the slicing and elution of these bands, and then testing for potentiating activity indicated that two of the three bands contained potentiating activity.
OKT3: a monoclonal anti-human T lymphocyte antibody with potent mitogenic properties.
Authors: Van Wauwe J P , De Mey J R , Goossens J G
Published: December 2022

OKT3, a monoclonal anti-human T cell antibody (IgG2), was found to induce DNA synthesis in human peripheral lymphocyte cultures. OKT3 induced maximal mitogenesis at a concentration of 10 to 20 ng/ml and was about 20-fold more potent than PHA as a mitogen. No high-dose inhibition of thymidine incorporation was noticed at concentrations up to 2.5 microgram OKT3/ml. The monovalent Fab fragment of OKT3 was also mitogenic but about 100 times less potent than the parent IgG. OKT3 appeared to be a T lymphocyte mitogen as only sheep red blood cell rosetting lymphocytes were responsive. Quantitative studies on the binding of 125I-labeled Fab fragment of OKT3 to human lymphocytes showed an average of 5.1 x 10(4) receptor sites/cell with an association of about 10(8) M-1 at 37 degrees C, with no heterogeneity of the cell binding sites. These data suggest a strong interaction of the monoclonal OKT3 with a limited number of identical T cell membrane receptors. As this interaction can trigger mitogenesis, the cell membrane determinant recognized by OKT3 could be described as a "T cell stimulation receptor." The mitogenecity of the lymphocytes is not solely dependent on cross-linking of these receptors.
Structural polymorphism of murine C4 and its linkage to H-2.
Authors: Natsuume-Sakai S , Kaidoh T , Nonaka M , Takahashi M
Published: December 2022

Heretofore unrecognized structural polymorphism of murine C4(Ss) was demonstrated by using two different techniques: immunofixation electrophoresis and immunofixation isoelectric focusing. By these methods C4 was demonstrated as a broad protein band in freshly bled EDTA-plasma of inbred strains and wild mouse lines. Seven variants of C4(Ss) were identified among a large number of mice tested:C4-v (pI 7.7) exemplified by strain SM/J, C4-B(pI 7.5) exemplified by B10, C4-k (pI 7.3) exemplified by C3H/He, C4-bactrianus (pI 7.2) exemplified by Mus m.bacterianus, C4-d.s(pI 7.0) exemplified by DBA/2 and SJL/J, C4-castaneus (pI 6.6) exemplified by Mus m.castaneus, and C4-NC(pI 6.3) exemplified by NC. F1 hybrid exhibited two C4 bands, each of which corresponds to C4 of a parent. The possibility that the observed polymorphism represents variation of Slp was ruled out because an identical C4 pattern was always observed between male and female mice. The observed structural variation of murine C4 is controlled by a single codominant locus localized within or in the proximity of the S subregion of H-2. This was shown by phenotyping several intra-H-2 recombinant strains and backcross progeny, (B10 X NC)F1 X B10 and (B10 X NC)F1 X NC. An alloantiserum specific for one of the C4 variants (C4-NC) was successfully produced in C3H/He mice by repeated injection of purified C4 of NC mouse. This finding suggests that observed C4 variants or at least some of them represent antigenically distinguishable allotypes of murine C4.
Demonstration of a chemotactic factor receptor on macrophages.
Authors: Snyderman R , Fudman E J
Published: December 2022

Certain synthetic N-formylated peptides are potent chemotactic agents for phagocytic cells. We have identified a specific, high affinity receptor for the chemotactic peptide fMet-Leu-[3H]Phe on inflammatory as well as on resident guinea pig peritoneal macrophages. The receptor on inflammatory macrophages has an equilibrium dissociation constant (KD) of 11 nM at room temperature, and there are approximately 10,000 binding sites per cell. The receptor on resident peritoneal macrophages has a KD of 7 nM with approximately 12,000 sites per cell. The increased chemotactic responsiveness of inflammatory macrophages as compared to resident macrophages is probably not due to differences in the fMet-Leu-[3h]phe receptor since the number of binding sites per cell and the KD are quite similar. The specificity of the binding site on both cell types for a series of N-formylated peptides correlates well with the ability of the peptides to initiate macrophage chemotaxis. These studies suggest that the chemotactic response of guinea pig peritoneal macrophages to N-formylated peptides is initiated by the binding of the peptides to a specific cell-surface receptor.
Identification of a major serum DNA-binding protein as factor B of the alternative complement pathway.
Authors: Gardner W D , Haselby J A , Hoch S O
Published: December 2022

One of the major proteins in human serum capable of binding DNA has been shown to be factor B of the alternative pathway of complement activation. This protein, designated DNA-binding protein-2 (DBP-2), is recognized by antisera directed against both factor B and its activated form, fragment Bb. Its m.w., charge microheterogeneity, and amino acid composition correspond closely with reported values for those properties of factor B. A radioimmunoassay was used to estimate the serum concentration of DBP-2 at 266 +/- 83 microgram/ml, which also corresponds with the level of factor B normally present in the serum. DBP-2 functions as factor B in the activation of factor B-depleted serum. Limited proteolytic treatment of DBP-2 produced a fragment pattern resembling that of factor B both in the m.w. of the fragments and their electrophoretic mobilities. By means of DNA affinity chromatography of the fragments produced by trypsinization, the DNA-binding domain of DBP-2 was localized.
Monogamous bivalency of IgG antibodies. I. Deficiency of branched ABHI-active oligosaccharide chains on red cells of infants causes the weak antiglobulin reactions in hemolytic disease of the newborn due to ABO incompatibility.
Authors: Romans D G , Tilley C A , Dorrington K J
Published: December 2022

This study shows that monogamous bivalency of human IgG anti-A and anti-B is necessary to maintain sensitization of red cells in the antiglobulin test. On red cells of infants and of adults of i phenotype, the known deficiency of branched ABHI-active oligosaccharide chains limits monogamous bivalency, and these accounts for the relatively weak direct antiglobulin reactions in hemolytic disease of the newborn due to ABO incompatbility. One corollary of this finding is that there is strong biologic selection against the transition on fetal red cells from the straight-chain i phenotype to branched-chain I phenotype, since such branching of cell-surface oligosaccharide chains would compromise ABO-incompatible pregnancies.
Evidence for the influence of the initial complement components on the assembly and activity of the membrane attack complex.
Authors: Boyle M D , Ohanian S H
Published: December 2022

The failure of functionally purified C5gp to reconstitute the hemolytic complement (C) activity of C5-deficient human serum was studied. The lack of hemolytic activity of C5gp in this system could not be correlated with the failure of EAC1-3hu to bind and activate C5gp, but was related to the failure of EAC1-3hu5gp6hu to efficiently bind C7hu in a form that would lead to lysis when HuC8 and HuC9 were added. This failure was not observed with EAC1-3gp5gp6hu or EAC1-3hu5hu6hu, which could be lysed with any combination of human or guinea pig C7 through C9. The implications of these findings on the control of the lytic C attack mechanism by the initial components in the C cascade are discussed.
T cell maturation: thymocyte and thymus migrant subpopulations defined with monoclonal antibodies to MHC region antigens.
Authors: Scollay R , Jacobs S , Jerabek L , Butcher E , Weissman I
Published: December 2022

The maturation sequences of thymocytes is known to some extent: A generative layer of subcapsular large lymphoblasts gives rise to a major population of small cortical thymocytes and a minor population of midsize medullary thymocytes. The relative contribution of these three populations to the peripheral T cell populations is not yet known. In this study, subcapsular lymphoblasts, cortical small cells, medullary cells, and thymic emigrant cells have all been analyzed by immunofluorescence for expression of the antigens H-2D, I-A, H-2K, and TL. H-2D is expressed brightly on all subcapsular large cells, dimly on cortical small cells, and brightly on all migrants, cortisone-resistant thymocytes (CRT), and peripheral T cells. I-A can be detected at low levels on 30 to 50% of cells in all the thymic subpopulations, and on 30 to 50% of migrants and peripheral T cells. Fifty to 80% of small cortical cells do not express detectable H-2K, but all the other subpopulations, both inside and outside the thymus, stain uniformly quite brightly. TL3 is expressed on 70 to 80% of subcapsular and cortical thymocytes, 30 to 40% of CRT, is undetectable on migrants but can be seen at low levels on 10 to 20% of spleen and lymph node T cells. The possibility that some or all of these antigens represent stable markers of separate lineages rather than unstable, stage-specific markers is discussed.
C5a induced tracheal contraction: a histamine independent mechanism.
Authors: Regal J F , Eastman A Y , Pickering R J
Published: December 2022

C5a, a peptide derived from the fifth component of complement, caused significant prolonged smooth muscle contraction in isolated guinea pig trachea. Diphenhydramine, a histamine receptor antagonist of the H1 type, had no effect on either the rate, amplitude or duration of C5a induced tracheal contraction, whereas it significantly inhibited the tracheal response to exogenous histamine. Diphenhydramine also caused a significant delay in the response to compound 48/80 in normal guinea pig trachea and to antigen in actively sensitized trachea, indicating that the antihistamine was capable of inhibiting tracheal contractions to endogenously released histamine. C5a induced tracheal smooth muscle contraction was also unaffected by antagonists of H2, muscarinic cholinergic and alpha adrenergic receptors. These results indicate that C5a induced tracheal contraction is independent of histamine and is potentially a mediator of allergic bronchospasm.
Suppression of the benzylpenicilloyl- (BPO) specific IgE formation with isologous anti-idiotypic antibodies in BALB/c mice.
Authors: Blaser K , Nakagawa T , de Weck A L
Published: December 2022

In vivo effects of actively produced or passively administered isologous anti-idiotypic antisera (aId) on the benzylpenicilloyl- (BPO) specific IgE and IgG formation in BALB/c mice have been studied. Isologous anti-BPO aId were raised in BALB/c mice by immunization with purified anti-BPO antibodies isolated from ascites induced with BPO-bovine gamma-globulin in the same mouse strain. Mice producing isologous anti-BPO aId exhibited long-term suppression of BPO-specific IgE and IgG antibody responses induced by BPO-ovalbumin (BPO-OVA) in aluminum hydroxide. Simultaneously, they produced increased amounts of anti-BPO aId after each challenge with the BPO-OVA antigens. Passive administration of isologous anti-BPO aId into syngeneic mice previously sensitized with BPO-OVA caused depression of BPO-specific IgE antibody levels for 2 to 3 weeks. When anti-BPO IgE had again reached its previous level, passively administered aId had decreased to the level of untreated mice. Passive administration of anti-BPO aId also depressed the primary anti-BPO IgE formation for 2 to 3 weeks. In all these experiments the IgE antibody formation against the carrier proteins used for BPO-antigens was not affected. These results show that IgE and IgG antibodies share major idiotypic determinants and that IgE production is accessible to regulation by aId.
The murine B cell response to TNP-polyacrylamide beads: the relationship between the epitope density of the antigen and the requirements for T cell help and surface IgD.
Authors: Puré E , Vitetta E S
Published: December 2022

Spleen cells were cultured with high or low epitope TNP-polyacrylamide beads (TNP-PAB) in order to investigate the effect of epitope density on the requirements for T cell help and surface IgD on responding B cells. The response to low epitope density TNP-PAB was abolished by treatment with anti-Thy-1.2 and complement, whereas approximately 50% of the response to high epitope density TNP-PAB was retained after similar treatment. Thus, an increase in epitope density resulted in a decreased requirement for T cell help. An increase in epitope density was also associated with a decreased requirement for interaction of antigen and surface IgD as determined by "blocking" studies with anti-delta; further, the majority of the T-independent portion of this response was not blocked by anti-delta antibodies. This finding indicate that the T-independent portion of the anti-TNP response does not require interaction of antigen with surface IgD on B cells. These results are discussed in terms of differential cross-linking of IgM and IgD receptors on B cells by multivalent antigens.
Fc receptors of a human promyelocytic leukemic cell line: evidence for two types of receptors defined by binding of the staphylococcal protein A-IgG1 complex.
Authors: Crabtree G R
Published: December 2022

The specificity and kinetics of binding of purified monomeric human and murine myeloma immunoglobulins to Fc receptors were studied in a human promyelocytic cell line (HL-60). HL-60 cells contain approximately 20,000 Fc receptors per cell and bind human IgG1, IgG3 and mouse IgG2a with high affinity (dissociation constant of 5 to 10 nM). Kinetic studies of the binding of IgG1 to HL-60 cells demonstrate rapid exchange with ambient immunoglobulin with approximately one-half of the surface-bound IgG1 exchanging every 25 to 30 min at 37 degrees C. Estimation of the equilibrium binding constant from the rates of association and dissociation of IgG1 agrees well with the values obtained from Scatchard analysis of equilibrium binding of radioiodinated IgG1. Approximately one-half of the Fc receptors of HL-60 cells are capable of binding IgG1 complexed to Protein A. This result was independent of the concentration of Protein A (0.5 to 200 microM) or the time of incubation of IgG1 with Protein A. Studies in which Protein A was incubated with HL-60 cells at 37 degrees C then rapidly washed at 0 degrees C indicated that Protein A did not degrade Fc receptors or interact with the Fc receptor sites on HL-60 cells. The complexes formed between Protein A and IgG1 sedimented at 7 to 9S by ultracentrifugation. These results suggest that there are two types of Fc receptors on HL-60 cells, which can be distinguished by their ability to bind the IgG1-Protein A complex.