bluuebunny/crossref_metadata_2025 huggingface dataset:
Idiotypes and allotypes on Ia-binding alloactivated Lyt-1+,2-,3- T cells are coded for by genes linked to the igh-1 allotype locus.
Authors: Suzan M , Elliott B E , Rubin B
Published: December 2022

Xenogeneic antisera, designated 5936 and 6036, have been used in this laboratory to define 5936-idiotypes (Id) and 6036-T cell receptor (Tcr) allotype determinants, respectively, on populations of B6 anti-CBA MLC T blasts. The present experiments were carried out to determine a) whether T lymphocytes that bear 5936-Id also express antiserum 6036-defined Tcr allotypes; b) if so, what is the Lyt phenotype and c) specificity of this T lymphocyte population, and d) whether the genes coding for 5936-Id and 6036-allotypes are linked to immunoglobulin (Ig) allotype genes. The results showed that 5936-Id-bearing T lymphocytes were included in a subset of cells that expressed antiserum 6036-defined Tcr allotypic determinants and the Lyt-1+,2-,3- phenotype. By genetic segregation analysis it was shown that both 5936-Id and antiserum 6036-defined allotypic determinants on T cells were linked to Igh-1b allotypes. 5936-Id determinants were expressed on T lymphocytes of Igh-1b allotype strains, specific for allogeneic I-Ak but not on those specific for I-Ak/Ek molecules. In contrast, 6036-Tcr allotype determinants were present on T lymphocytes from Igh-1b allotype strains, specific for either I-Ak or I-Ak/Ek molecules. The results support the hypothesis that 5936-Id determinants are present only on a subset of anti-I-Ak T cell receptors, whereas 6036-Tcr allotype determinants are shared among T cell receptors of several unrelated specificities from Igh-1b allotype-bearing strains.
Isolation of cross-linked IgE-receptor complexes from rat macrophages.
Authors: Finbloom D S , Metzger H
Published: December 2022

Receptors for IgE on macrophages have been characterized by binding assays (1-3), but to date there has been only one report on the isolation of this receptor from macrophages, with use of the cell line U937 (4). In that report the receptor was isolated by using a heavily absorbed polyclonal antibody raised against lymphocytes bearing receptors for IgE (5). Monomeric IgE binds so weakly to macrophages that affinity chromatography of IgE-receptor complexes, such as has been used for isolation of the receptors for IgE on basophils (6) and for IgG on macrophages (7), cannot be readily accomplished. We have used oligomers of IgE to enhance the binding of IgE to macrophages (3), but this alone would not be sufficient because--depending on whether the receptors are multi- or univalent--once the cells are solubilized, multipoint attachment would again be reduced if not abrogated. In this report we describe the use of cross-linking reagents to stabilize further the interaction between IgE and its receptor on peritoneal macrophages. With this approach we have found that the receptor is likely to be composed of two chains whose gross properties are similar to the polypeptides constituting the receptor with high affinity for monomeric IgE on rat basophilic leukemia cells and mast cells.
The ontogeny of antigen-presenting cells in fetal thymus evaluated by MLR stimulation.
Authors: Robinson J H
Published: December 2022

This study demonstrates that cells with the characteristics of antigen-presenting cells (APC) are present in murine thymus from as early as 14 days gestation, around the time that T lymphopoiesis is initiated in the embryo. Thymic APC were identified as la+ adherent cells capable of presenting alloantigens to T cells in MLC. The possible role of these cells in thymocyte differentiation is discussed.
Anti-receptor antibody-induced H-Y-specific delayed-type hypersensitivity responses in nonresponder mice.
Authors: Sunday M E , Dorf M E
Published: December 2022

The present study examines an antiserum prepared against antigen-reactive T cells that induces murine H-Y-specific delayed-type hypersensitivity (DTH) responses. This anti-H-Y receptor antibody (ARA) was raised in C57BL/6 male mice against splenic T lymphocytes from H-Y immune syngeneic females. Subcutaneous administration of ARA to cyclophosphamide-pretreated C57BL/6 females is able to induce H-Y-specific delayed-type footpad swelling responses. The DTH inducing capacity in ARA was selectively retained on rabbit anti-mouse immunoglobulin columns and was absorbed completely by H-Y immune lymphoid cells from C57BL/6 females. The induction of H-Y DTH reactivity was due at least in part to the activation of H-Y antigen-specific T lymphocytes that could adoptively transfer DTH-like responses to naive female mice. ARA induces DTH responses in strains with the same lgh regions, including selected strains of H-Y nonresponders. Therefore, MHC-linked lr genes do not appear to be as critical when responses are triggered by ARA instead of by antigen. Possible mechanisms for the induction of immune responses by ARA are discussed.
Local production of IgG4 in human colostrum.
Authors: Keller M A , Heiner D C , Kidd R M , Myers A S
Published: December 2022

Total IgG4 levels were determined in 27 colostrum and 27 plasma paired samples by using RIA techniques, and total IgG was determined on the same pairs by using radial immunodiffusion. In colostrum, the mean IgG4 level was 4.6 micrograms/ml (0.6 to 19.0), and in the plasma the mean IgG4 level was 170.5 micrograms/ml (30 to 920). IgG averaged 42.3 micrograms/ml (12 to 240) in colostrum and 7980.9 micrograms/ml (3250 to 16,000) in plasma. Of colostral IgG, 15.3% was IgG4, whereas only 3.5% of plasma IgG was IgG4. Specific IgG4 antibodies to beta-lactoglobulin, bovine serum albumin, bermuda grass, and alpha-gliadin were also assayed. In six patients, strong evidence was found for local mammary production of IgG4-specific antibodies.
Capping of complement receptors on human neutrophils induced by group A streptococcal cell walls.
Authors: Pryzwansky K B , MacRae E K , Lambris J D
Published: December 2022

Peptidoglycan-polysaccharide polymers derived from group A streptococcal cell walls (PG-PS) were opsonized with either purified C3 or normal human serum and were used as a probe to investigate the mobility of CR1 and CR3, the C3b and iC3b receptors, respectively, on human neutrophils. Incubation of monolayers or cell suspensions of neutrophils with PG-PS opsonized with C3b or serum resulted in capping of PG-PS, as detected by fluorescein-labeled antibody to PS. No binding of PG-PS to neutrophils was observed with heat-inactivated serum. By 30 min the cell walls were internalized and observed in one to three vacuoles. Capping was totally inhibited when PG-PS opsonized with C3b or serum was preincubated with Fab'-anti-C3b. Similar inhibition was observed when C3b-opsonized PG-PS was incubated with neutrophils that were preincubated with anti-CR1 or fluid-phase C3b; only partial inhibition of neutrophil capping was observed by using serum-opsonized PG-PS. Because anti-CR1 blocks only the C3b receptor, the cap formation observed with serum-opsonized PG-PS is probably due to CR3. These results suggest that both CR1 and CR3 on neutrophils cap after stimulation by group A streptococcal cell wall fragments.
Immune lysis of reconstituted myelin basic protein--lipid vesicles and myelin vesicles.
Authors: Boggs J M , Samji N , Moscarello M A , Hashim G A , Day E D
Published: December 2022

Complement-mediated lysis of reconstituted lipid-myelin basic protein (BP) vesicles and myelin vesicles due to antibody raised against BP and isolated myelin is measured by determination of the amount of a water-soluble spin label, tempocholine chloride, released from the vesicles. The response is shown to be antigen-specific, antibody-dependent, and complement mediated. The relative response to different anti-BP antibody samples is similar to that determined by radioimmunoassay procedures. In contrast to immunoassays with BP in aqueous solution, this method measures immune recognition of the protein in either a synthetic or a natural membranous environment. This is important because this protein has been shown to have a different conformation when bound to lipid bilayers than in aqueous solution and its conformation depends on lipid composition. It is also a more rapid method because no separation of spin label still trapped in the vesicles and that released due to immune lysis is required. In synthetic membranes consisting of sphingomyelin, cholesterol, and an acidic lipid, either phosphatidylglycerol, phosphatidic acid, or phosphatidylserine, the response was greatest when the acidic lipid was phosphatidic acid. The response did not depend significantly on the antigen concentration expressed as molar ratio of BP to sphingomyelin, over the range 0.15:600 to 2:600, although it decreased at molar ratios less than 0.15:600. The antigen density required for immune lysis of vesicles containing this protein antigen is similar to that reported elsewhere for lipid antigens, although the time required for maximal lysis was greater. Both anti-BP and anti-myelin antibodies caused a greater specific complement-mediated response with synthetic vesicles than with myelin vesicles, which may be due to the different lipid and/or protein composition of myelin. Response was also obtained with the myelin vesicles, however, indicating that some determinants of BP can be recognized on the surface of the bilayer in isolated myelin by anti-BP.
Interleukin 2-mediated immune interferon (IFN-gamma) production by human T cells and T cell subsets.
Authors: Kasahara T , Hooks J J , Dougherty S F , Oppenheim J J
Published: December 2022

Human interleukin 2 (IL 2, or T cell growth factor), which was free of lectin and interferon activity (IFN), induced human peripheral T lymphocytes to produce immune IFN (IFN-gamma). In contrast, non-T cells and macrophages did not produce IFN-gamma in response to IL 2. IL 2 acted directly on unstimulated T cells to induce IFN-gamma production, and also acted in synergy with a suboptimal dose (2 micrograms/ml) of concanavalin A (Con A) to enhance IFN-gamma production. The IFN-gamma-inducing activity of partially purified IL 2 was absorbed along with the IL 2 activity by murine IL 2-dependent CT-6 cell line cells. This further supports the view that IFN-gamma-inducing activity is identical to IL 2. When T cells were separated further into helper/inducer T4+ and suppressor/cytotoxic T8+ subsets by negative selection with monoclonal antibody and complement, both T4+ and T8+-enriched cells produced significant levels of IFN-gamma in response to IL 2. Complete removal of macrophages from purified T lymphocyte populations by treatment of OKM1 plus complement consistently reduced IFN-gamma production in response to IL 2 to a limited degree; readdition of macrophages restored IFN-gamma production by both T cell subsets. This observation that IL 2 contributes to the production of IFN-gamma by human lymphocytes suggests that a cascade of lymphocyte-cell interactions participates in human immune responses.
Mechanisms of suppression of mouse mesangial cell proliferation by macrophage supernatants.
Authors: Ooi Y M , Weiss M A , Hsu A , Ooi B S
Published: December 2022

The monocyte/macrophage has been identified as an effector cell infiltrating the glomerulus in human and experimental nephritis. To clarify the role of the macrophage in this context, an in vitro system was developed in which mouse mesangial cell cultures were maintained. Macrophage supernatants were obtained from peritoneal macrophages harvested from either resident or endotoxin-stimulated C57BL/6J male mice cultured for 24 hr. Incubation of mesangial cell cultures with macrophage supernatants resulted in depression of mesangial cell metabolism as indicated by incorporation of (3H)-thymidine; the effect was more marked when supernatants of endotoxin-treated mice were used. The molecular mechanisms by which suppression was obtained was clarified by experiments fractionating macrophage supernatants by G-100 column chromatography. By this means, two fractions were obtained with different molecular and physiologic properties. One fraction, a molecular size of 14,600 to 29,000 daltons, was shown to mediate the suppressive effect by stimulating endogenous mesangial cell PGE synthesis; additionally, a novel molecular species was identified, which was biologically active at higher concentrations of macrophage supernatants, had a larger molecular size (29,000 to 68,000 daltons), exerted its suppressive effect by an independent mechanism, and accounted for the inability of indomethacin pretreatment of mesangial cells to abrogate completely the suppressive effect of macrophage supernatant at higher concentrations.
Clearance kinetics and fate of mouse IgA immune complexes prepared with monomeric or dimeric IgA.
Authors: Rifai A , Mannik M
Published: December 2022

To determine the pathophysiologic mechanism(s) involved in experimental IgA nephropathy, the clearance kinetics and tissue distribution of soluble IgA immune complexes in mice were investigated. Purified radiolabeled dimeric (dIgA) and monomeric (mIgA) IgA antidinitrophenyl, obtained from MOPC-315, were covalently cross-linked with a bivalent affinity-labeling antigen, bis-2,4-dinitrophenyl pimelic ester. After i.v. injection, heavy polymers (greater than 1.2 X 10(6) m.w.) were rapidly removed from circulation. Analysis of circulating intermediate-latticed complexes by gradient polyacrylamide gel electrophoresis indicated that polymers with a minimal composition of four dIgA or eight mIgA were required for rapid elimination. The dIgA and mIgA complexes with lattices smaller than this critical size were removed at slower rates (yielding a t1/2 of 35 min for complexes with dIgA and a t1/2 of 60 min for complexes with mIgA). Tissue distribution of both dIgA and mIgA immune complexes was similar. The liver was the major organ involved in uptake of IgA immune complexes with an insignificant amount in the bile. Heavy polymers of dIgA or mIgA were predominantly localized in the hepatic nonparenchymal cells.
Expression of a bone marrow-associated Ly-6 determinant on the T cell population expanding in the lymph nodes of the autoimmune mouse strain MRL/Mp-lpr/lpr.
Authors: Melino M R , Dumont F J , Habbersett R C , Hansen T H
Published: December 2022

In this report we describe the reactivity patterns of two monoclonal anti-Ly-6.2 antibodies toward lymph node (LN) cells of the autoimmune MRL/Mp-lpr/lpr (lpr) and the normal congenic MRL/Mp-+/+ (+/+) mouse strains. The monoclonal antibody 34-11-3, which has previously been found to detect a LN-associated Ly-6.2 antigen, reacted with both lpr and +/+ LN cells. Another monoclonal antibody, 34-10-7, which has been demonstrated to detect a bone marrow- (BM) associated determinant, was found to react with a small proportion of +/+ LN cells and unexpectedly with a high percentage of lpr LN cells. The expression of this BM determinant found in the LN of lpr mice was age dependent, and its presence on Thy-1.2+ cells increased with the expansion of a subset of Lyt-1+2- cells. In contrast, dual labeling experiments showed that in +/+ and young lpr mice a small subset of Lyt-1+2+ cells express this BM-associated Ly6.2 determinant. Therefore these findings demonstrate that the lpr gene-dependent T cell expansion in the LN results in both aberrant expression and association of lymphocyte cell surface markers.
Functional studies on B cell hybridomas with B cell surface antigens. I. Effects of anti-immunoglobulin antibodies on proliferation and differentiation.
Authors: Hamano T , Asofsky R
Published: December 2022

B cell hybridomas with Ia and IgM molecules on the cell membrane were treated with either purified goat anti-mouse mu antibody (anti-mu) or monoclonal rat anti-mouse IgM antibody (anti-IgM). The spontaneous uptake of [3H] thymidine by these cells was markedly inhibited by both reagents. These hybrid cells could be induced to differentiate into IgM-secreting cells in the presence of these reagents at high frequency. Furthermore, the induction of IgM secretion by B cell hybridomas treated with these antibodies was completely T cell independent, and cell division was not required for the differentiative response to anti-mu. In addition, F(ab')2 fragments of anti-mu showed more effects on proliferation and differentiation of these cells than intact anti-mu. Interestingly, TH2.54, a subline of B cell hybridomas, could generate IgG2a production as well as IgM when incubated with anti-mu. These findings suggest very strongly that the interaction of either goat anti-mu or monoclonal rat anti-IgM with surface IgM molecules on the cell membrane of the B cell hybridomas inhibits in vitro spontaneous proliferation, and results in providing signals for differentiation into Ig-secreting cells without T cell factors.
Heterologous antisera to Lyt-1+, 2- -derived antigen-binding factor detect a subfactor of an antigen-specific suppressor factor and cell surface proteins on Lyt-1+, 2- and Lyt-1-, 2+ T cells.
Authors: Cone R E , Rosenstein R W , Tite J , Ptak W , Gershon R K
Published: December 2022

Rabbits were immunized with TNP-specific Lyt-1+, 2- T cell-derived, antigen-binding proteins (PCI-F) released by T cells sensitized by skin painting with picrylchloride. The resulting antiserum (anti-PCI-F) bound to PCI-F and TNP-specific factors that suppressed delayed hypersensitivity (TSF) known to be comprised of PCI-F and Lyt-2+ -derived polypeptides released by cells sensitized by injection of trinitrobenzenesulfonic acid (TNBSF). Anti-PCI-F bound to T lymphocytes and 68,000 to 72,000 m.w. T cell surface proteins but not B cells on their surface proteins. Anti-PCI-F bound to both Lyt-1+ and Lyt-2+ T cells and surface proteins. A comparison of anti-PCI-F with anti-TSF indicates that anti-TSF contains specificity for Ly-2+ T cell-derived components of TSF and T cells not present in anti-PCI-F. The possibility of multiple isotypes of T cell receptors and antigen-binding molecules is discussed.
Sensitization of circulating basophils in guinea pig recipients of passive transfer of cutaneous basophil hypersensitivity (CBH) with immune serum: antigen-specific histamine release in vitro.
Authors: Lett-Brown M A , Mitchell E B , Askenase P W
Published: December 2022

An in vitro histamine release assay was used to test the hypothesis that passive sensitization of circulating basophils is associated with the activity of immune serum that transfer the ability to elicit cutaneous basophil hypersensitivity (CBH) reactions. Systemic i.v. transfer of several types of immune sera that mediate CBH also led to passive sensitization of circulating basophils for antigen-specific release of histamine in vitro. In addition, we found that immune serum passively sensitizes basophils in vitro. Thus immune sera had three activities that are probably interconnected: sera will 1) passively transfer CBH in vivo, 2) passively sensitize basophils in vivo, and 3) passively sensitize basophils in vitro. These results suggest that passive sensitization of circulating basophils by immune serum contributes to the mechanism by which antibodies transfer the ability to elicit CBH reactions.
Human natural killer cells analyzed by B73.1, a monoclonal antibody blocking Fc receptor functions. II. Studies of B73.1 antibody-antigen interaction on the lymphocyte membrane.
Authors: Perussia B , Acuto O , Terhorst C , Faust J , Lazarus R , Fanning V , Trinchieri G
Published: December 2022

In this paper, we characterize the antigen recognized by the monoclonal antibody B73.1 and the modification occurring at the membrane of the positive cells after interaction with the antibody. The B73.1-defined antigen is a protein of 50,000 to 72,000 daltons that is sensitive to pronase but not to trypsin treatment. B73.1 antibody, and its F(ab')2 fragment, directly block, at high concentrations, the binding of IgG antibody-sensitized erythrocytes to the Fc receptors (FcR) of a subpopulation of lymphocytes and neutrophils. B73.1 antibody dissociates rapidly from the positive cells, but concomitant modulation of both B73.1 antigen and FcR is induced when cells are incubated in the continuous presence of antibody or when B73.1 antibody is cross-linked at the cell membrane with an anti-mouse immunoglobulin antiserum. Reaction of lymphocytes with immune complexes also induces modulation of both FcR and B73.1 antigen, without affecting the expression of other antigens on the positive cells. The possibility that the antigen is internalized and digested by the cell after reaction with the antibody is discussed. B73.1 antibody inhibits antibody-dependent cytotoxicity mediated by lymphocytes (K cells) and neutrophils, whereas it does not affect spontaneous cytotoxicity of NK cells. These results suggest the B73.1-defined antigen might be the FcR or a structure closely related to it on K/NK cells.
Epitopes of peptide 43-88 of guinea pig myelin basic protein: localization with monoclonal antibodies.
Authors: Fritz R B , Chou C H
Published: December 2022

Two monoclonal antibodies, one raised by immunization with mouse myelin basic protein (MBP) and the second raised by immunization with peptide 68-88 of guinea pig MBP, were compared with respect to specificity. The former antibody (15.32) cross-reacted completely with rat, guinea pig, human, and bovine MBP. It also reacted with peptide 43-88 from each MBP. The latter antibody (22.17) was nonreactive with MBP, but cross-reacted with peptide 43-88 from rat, human, guinea pig, and bovine MBP. When tested with small peptides derived from peptide 43-88, antibody 22.17 reacted with an epitope in the C-terminal region. Antibody 15.32 reacted with an epitope in the N-terminal half of the peptide. The data show that 22.17 reacted with a unique epitope associated only with free peptide, whereas 15.32 recognized an epitope common to both peptide 43-88 and MBP.
Encephalitogenic activity of the small form of mouse myelin basic protein in the SJL/J mouse.
Authors: Chou C H , Shapira R , Fritz R B
Published: December 2022

Mouse myelin basic proteins (MBP) were prepared by ion-exchange chromatography of an acid extract of homogenized, delipidated mouse brain. The use of a linear salt gradient during ion-exchange chromatography gave three peaks, 1, 2, and 3, of MBP. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of these peaks showed that peaks 2 and 3 were a mixture of the large and small forms of mouse MBP, whereas peak 1 was solely the small form. Tryptic peptides of mouse and rat small form MBP were compared by high-performance liquid chromatography. The elution times and absorbances at 210 nm were identical for 16 of 21 peaks derived from small form MBP of the two species. Amino acid analysis showed that 10 corresponding peaks from the small form of mouse and rat MBP had identical amino acid composition. When tested for encephalitogenicity in SJL/J mice, both the mixture of large and small forms of mouse MBP and the small form mouse MBP were highly encephalitogenic.
Soluble factors involved in B cell differentiation: identification of two distinct T cell-replacing factors (TRF).
Authors: Nakanishi K , Howard M , Muraguchi A , Farrar J , Takatsu K , Hamaoka T , Paul W E
Published: December 2022

Highly purified B lymphocytes cultured with affinity-purified goat anti-mouse IgM antibodies and B cell growth factor (BCGF) proliferate but fail to differentiate into immunoglobulin-synthesizing cells during 4-day cultures. Induction of immunoglobulin (Ig) synthesis depends on the presence of two additional T cell-derived factors (T cell-replacing factors [TRF]). One TRF, designated B15 1K 12-TRF, is found in the supernatant of B15 1K 12 T hybridoma cells. It is required relatively early in these cultures and appears to cause an increase in cell yield as well as Ig synthesis. The second factor, designated EL-TRF, is found in PMA-induced EL-4 supernatant. It appears to be different from both BCGF and IL 2 in that it can be separated from the former by isoelectric focusing and from the latter by phenyl-Sepharose chromatography. EL-TRF is still active if added on the last day of a 4-day culture. A model for the action of anti-IgM and these three T cell-derived factors in B cell activation and differentiation is proposed.
In vitro analysis of allogeneic lymphocyte interaction. VI. I-J-restricted self-reactive and alloreactive components of allogeneic effect factor (AEF) are distinct I-J- molecules that interact with I-J+ T cells and antigen-presenting cells.
Authors: Delovitch T L , Kaufman K , Gorczynski R M
Published: December 2022

An allogeneic effect factor (AEF) generated across an I-J incompatibility was derived from MLR cultures of alloactivated B10.A(3R) responder T cells and irradiated T cell-depleted B10.A(5R) stimulator spleen cells. This AEF consists of two soluble, secreted I-J-restricted helper components. One helper component, TH-I, recognizes self-I-J determinants on an I-J+ B10.A(3R) antigen-presenting cell (APC), whereas the other helper component, TH-II, recognizes allo-I-J determinants on an I-J+ B10.A(5R) APC. TH-I-B10.A(3R) APC interaction and TH-II-B10.A(5R) APC interaction each induce an in vitro primary anti-SRBC PFC response of either B10.A(3R) or B10.A(5R) B cells. Thus, I-J determinants serve as restricting elements during a TH-APC and not an APC-B interaction. TH-II mediates the I-J-restricted allogeneic effect required to activate T suppressor (TS) cells during a contact sensitivity or delayed-type hypersensitivity response to hapten-conjugated syngeneic lymphoid cells. This indicates that TH-II is also involved in a TH-pre-TS type interaction. TH-I and TH-II are I-J-, 68,000 m.w. molecules that differ by about 0.10 units in their pl values. Their charge difference is not due to an altered amount of sialylation or phosphorylation, but may result either from another form of altered glycosylation and/or from a difference in their primary structure. Peptide mapping analyses reveal that TH-I and TH-II possess at least 80% shared peptides and may be structurally homologous but nonidentical molecules; however, the possibility that TH-I and TH-II are structurally identical cannot be eliminated. Papain cleaves TH-I and TH-II into a 40,000 m.w. fragment. No subunit structure of TH-I and TH-II is apparent. It is suggested that TH-I and TH-II are I-J- -activated responder T cell-derived receptors for self-I-J and allo-I-J determinants, respectively.
Human soluble Fc gamma-binding material. I. Immunochemical properties of the material produced by the T cell line KE37.
Authors: Caraux J , Chichehian B , Serrou B , Weigle W O
Published: December 2022

A soluble Fc gamma-binding material (S-Fc gamma BM) is produced by the Fc gamma receptor-bearing human T cell line KE37 but not by the two Fc receptor-negative cell lines Molt 4 and Reh 6. The S-Fc gamma BM has specific affinity for the Fc fragment of IgG and none for the Fab fragments. It can be obtained in radioactive form after internal labeling with radioactive amino acids. It can then be isolated from the supernatant of the KE37 cell line by affinity chromatography, gel filtration and isoelectric focusing. The subunit components of S-Fc gamma BM are 23,000-dalton polypeptide chains. The soluble form is a dimer (42,000 to 45,000 m.w., pl 6.2), which retains Fc gamma-binding activity after isolation. Higher m.w. polymers of the 23,000-dalton subunits are also present in the supernatant of the KE37 cell line. These polymers are relatively insoluble in aqueous solvents but possess Fc gamma-binding activity. The S-Fc gamma BM molecules might be derived from a membrane-inserted form by restricted proteolytic cleavage at connecting regions of a larger polypeptide chain folded into 23,000-dalton subunits.
Studies of antigen binding on human basophils. I. Antigen binding and functional consequences.
Authors: MacGlashan D , Lichtenstein L M
Published: December 2022

We developed an assay to study simultaneously antigen binding and its functional consequences on human basophils. Using a 125iodine-labeled penicillin-human serum albumin conjugate, we were able to detect as few as 100 molecules of antigen bound to purified basophils. We found that histamine release could be initiated with fewer than 100 molecules of antigen and that the optimum for histamine release occurred at a concentration at which 10 to 15% of the available antibody-binding sites were occupied. Analysis of the binding kinetics in the presence of monovalent hapten allowed a calculation of the affinity constant for the antibody:hapten association; the value of 2 to 3 X 10(6)/Msec confirmed an earlier independent calculation. Binding data also suggested a 25% fraction of the bound antigen was binding in monogamous bivalent form. It is anticipated that studies of this kind will delineate the nature of the antibody-antigen reaction on cell surfaces.
Identification and in situ localization of the "thymic nurse cell" in man.
Authors: van de Wijngaert F P , Rademakers L H , Schuurman H J , de Weger R A , Kater L
Published: December 2022

The observation of the "thymic nurse cell" (TNC), a reticuloepithelial cell with intracytoplasmic lymphocytes, in suspension of murine thymic tissue prompted us to investigate the existence of this cell in cell suspension, as well as in tissue sections of the human thymus. TNC-like cells were enriched in suspension by enzymatic disintegration of thymic tissue and 1 X G sedimentation over 50% fetal calf serum gradients. TNC-like cells were negative for lysosomal enzymes: in this respect, as well as in light microscopic morphology, the cells were different from tissue macrophages with intracytoplasmic lymphocytes. In electron microscopy, TNC-like cells showed reticuloepithelial characteristics. In 1-micron tissue sections, clusters of lymphocytes with a possible reticuloepithelial nucleus were observed close to blood capillaries in the cortical area. Ultrastructural analysis confirmed the epithelial nature of this cell, as well as its location adjacent to blood capillaries. We concluded that there is in situ existence of TNC in man. This observation enables studies on the role of TNC in intrathymic T cell maturation.
Biochemical analysis of initial triggering events of IgE-mediated histamine release from human lung mast cells.
Authors: Ishizaka T , Conrad D H , Schulman E S , Sterk A R , Ishizaka K
Published: December 2022

Mast cells were isolated from human lung tissues by counter current centrifugation elutriation, followed by flotation through Percoll gradients. Purified human mast cells released histamine upon challenge with anti-IgE. An optimal concentration of anti-IgE for maximum histamine release from human lung mast cells was comparable to that required for histamine release from normal human basophil granulocytes. Human lung mast cells could be passively sensitized with mouse monoclonal IgE antibody for antigen-induced histamine release. Bridging of cell-bound IgE molecules on human mast cells by anti-IgE or its F(ab')2 fragments induced phospholipid methylation and an increase in intracellular cyclic AMP (cAMP). Incorporation of [3H]methyl groups into phospholipid reached a maximum at 30 sec after challenge with anti-IgE, whereas intracellular cAMP reached a maximum at 1 min. Both values declined to base line levels within 2 to 3 min. These biochemical events were followed by Ca2+ influx and histamine release. Ca2+ uptake and histamine release reached maximum at 2 to 3 min and 5 to 8 min, respectively. Neither phospholipid methylation nor initial rise in cAMP was inhibited by indomethacin, which indicates that these biochemical events are not the result of prostaglandin synthesis. However, inhibition of phospholipid methylation by inhibitors of S-adenosyl-L-methionine-mediated methylation, such as 3-deazaadenosine and S-isobutyryl 3-deazaadenosine, inhibited not only phospholipid methylation but also cAMP rise and subsequent Ca2+ uptake and histamine release. The results indicate that phospholipid methylation induced by bridging of IgE receptors on human mast cells is essential for Ca2+ influx and histamine release.
Delayed hypersensitivity to Newcastle disease virus in high and low interferon-producing mice.
Authors: De Maeyer E , De Maeyer-Guignard J
Published: December 2022

Since it was previously shown that IFN, under certain conditions, can stimulate sensitization to SRBC, we examined the intensity and duration of DH to NDV in high and low IFN-alpha and -beta producing mice that carried either the h or I allele at the If-1 locus. In C57BL/6 mice (If-1h) DH to NDV is of higher intensity and longer duration than in BALB/c (If-1l). Evidence that this difference is related to the higher IFN-alpha and -beta production induced by NDV in C57BL/6 mice was obtained by comparing DH to NDV in C57BL/6 (If-1h) mice and in mice of three congenic strains, carrying the If-1l allele on a C57BL/6 background (B6.C-H-28c-If-1l). In the latter, DH to NDV was much more of BALB/c than of C57BL/6 type, since after footpad challenge a significant reaction was only observed at 24 hr and no longer at 48 hr. When the low endogenous IFN production of the If-1l congenic mice was compensated for by giving extra IFN-alpha and -beta a few hours after sensitization with NDV, DH was enhanced. If, on the other hand, anti IFN-alpha and -beta globulins were administered to either C57BL/6 or If-1l congenic mice immediately after sensitization with NDV, DH was decreased. These results indicate that, on a C57BL/6 background, the establishment of DH to NDV is influenced by the alleles at If-1, determining the levels of endogenous IFN-alpha and -beta induced by NDV.
gamma Interferon production appears to predict time of recurrence of herpes labialis.
Authors: Cunningham A L , Merigan T C
Published: December 2022

Peripheral blood mononuclear cells separated from the blood of 29 volunteers within 3 wk of the onset of recurrent oral herpes labialis spontaneously secreted IFN-gamma (and small amounts of IFN-beta) into the culture medium in varying amounts (mean = 77 U/ml, SE = 17). However, interferon could not be detected in the serum of 10 of these patients tested. In the group as a whole, peak levels of interferon were secreted in vitro at 6 to 20 days after the onset of herpes labialis. Serial studies in eight patients showed peak production in the second or third week, with subsequent decrease to undetectable levels at 6 wk. A strong correlation between peak supernatant interferon level and the time to the next recurrence of herpes labialis in each patient was noted (r = 0.82, p less than 0.0001). Herpes simplex antigen-stimulated mononuclear cell cultures from each patient produced a mixture of IFN-alpha and IFN-gamma. A less marked but still significant correlation was noted between the peak mixed interferon level and the inter-recurrence interval (r = 0.52, p less than 0.005). These results suggest that a recurrent herpes labialis acts as an in vivo stimulus to the induction of IFN-gamma-producing cells that circulate in peripheral blood. The IFN-gamma produced is either a direct determinant of frequency of recurrence of herpes or a quantitative marker for other cellular immune events determining frequency.
Target determinants for F1 hybrid anti-parental H-2d cell-mediated lympholysis: self antigens controlled by the D end.
Authors: Nakamura I , Nakano K , Cudkowicz G
Published: December 2022

The immunogenetic specificity and reactivity with syngeneic target cells were determined for (C57BL/6 x DBA/2)F1 anti-parental DBA/2 cytotoxic T lymphocytes (CTL) elicited in primary mixed spleen cell cultures. A panel of peritoneal exudate cells (PEC) from mice bearing nonrecombinant and recombinant H-2-Tla haplotypes and their F1 hybrids was used as the source of target and inhibitor cells for direct lytic and competitive inhibition assays. PEC of H-2d and several recombinant haplotypes bearing the d alleles at the D region, including H-2u, were as susceptible to lysis as parental DBA/2 PEC, irrespective of non-N-2 genetic constitution. Those of H-2b, H-2k, H-2s, and recombinant haplotypes not carrying the d allele in the D region were not lysed above the background levels. Syngeneic F1 PEC were not lysed by CTL, but were nevertheless capable of inhibiting the lysis of DBA/2 PEC, albeit slightly less effectively than homozygous Dd-positive PEC inhibitors. Mapping by inhibition assays indicated that the presence of at least one copy of the H-2Dd allele was necessary and was sufficient to confer inhibitory capacity to H-2 heterozygous PEC. These results extend previous observations on primary F1 anti-parental H-2b and H-2k cell-mediated lympholysis (CML) and indicate generality of autoreactive F1 anti-parent CML responses against surface structures coded for or controlled by H-2K or H-2D region genes.
Phorbolester-treated human lymphocytes are susceptible to natural killer cell-mediated cytolysis.
Authors: Kabelitz D , Kunkel H G
Published: December 2022

The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) was found in this study to render normal human lymphocytes susceptible to allogeneic and autologous natural killer (NK) cell lysis. Both T and non-T cells became susceptible after culture for 3 days in the presence of 1 ng/ml TPA. Effector cells were nonadherent mononuclear cells of low density, enriched for large granular lymphocytes and HNK-1+ cells. Activation of effector cells with interferon increased lysis of TPA-treated lymphocytes. The present system may provide a new model to study NK cell target structures.
Two distinct suppressor T cells acting in concert cause suppression of cytolytic T lymphocyte (CTL) response to hapten-altered self in vivo.
Authors: Gautam S C , Beckman K D , Wong H L , Battisto J R
Published: December 2022

The participation of two subpopulations of suppressor T cells (Ts) active in the suppression of hapten-specific contact sensitivity (CS) was investigated in the down-regulation of in vivo development of CTL to hapten-altered self. We have shown that Ts efferent (Ts-eff) cell that is induced by tolerizing mice with an i.v. injection of hapten-coupled syngeneic spleen cells, and the auxiliary Ts cell (Ts-aux), which is generated by dermal application of hapten, together suppress the generation of CTL. Thus, when tolerant mice possessing Ts-eff cells were concomitantly sensitized for CTL and CS (which causes the arisal of Ts-aux and TDTH effector cells), the development of CTL was suppressed. Furthermore, adoptive transfer of lymph node cells from dermally sensitized mice into tolerant mice also suppressed the CTL response. Use of lymph node cells from mice pretreated with cyclophosphamide before dermal sensitization and therefore lacking Ts-aux cells was not efficient in suppressing the CTL response. Thus, neither Ts-eff alone nor TDTH in conjunction with Ts-aux were capable of suppressing the development of CTL. In addition to supporting the view that the in vivo generation of CTL is suppressed when both Ts-eff and Ts-aux cells are present, the data indicate that suppressor cells operational for one T cell-mediated response (CS) are equally functional for a separate unrelated one (CTL).
Delayed hypersensitivity in mast-cell-deficient mice.
Authors: Thomas W R , Schrader J W
Published: December 2022

The ability of mast cell-deficient Wf/Wf and W/Wv mice to produced delayed hypersensitivity responses was examined. The W/Wv mice did not have detectable mast cells and could not produce IgE-mediated passive cutaneous anaphylaxis. Mice of both genotypes produced large delayed hypersensitivity responses to the contact sensitizers oxazolone and picryl chloride. The responses were indistinguishable from responses of control mice when challenged with optimal or suboptimal doses of antigen. Delayed hypersensitivity could be transferred into Wf/Wf mice by an antigen-specific T cell line, and the proliferative responses in the lymph nodes of these mice after, painting with sensitizer, were normal.
Derivatized guanine nucleosides: a new class of adjuvant for in vitro antibody responses.
Authors: Goodman M G , Weigle W O
Published: December 2022

Guanine ribonucleosides, substituted at the C8 position with either a bromine or thiol group, are potent adjuvants when added to culture with antigen. Responses from both naive and antigen-experienced B cells are augmented by the presence of the nucleoside derivatives. Like the induction of B cell proliferation and polyclonal immunoglobulin secretion, enhancement of antibody responses is not attributable to structural analogy between 8BrGuo and the cyclic nucleotide 8Br-cGMP, because the latter compound is unable to augment the antibody response. The capacity of 8MGuo to augment both T-independent and T helper factor-supported antibody responses suggests that the nucleoside acts by directly interacting with B cells and/or antigen-presenting cells. 8MGuo retains its full adjuvant activity even when added 3 days after culture initiation, a time that is too late for freshly added T cells to support a response. Finally, supplementation of cultures of spleen cells from immunodeficient (CBA/N x CBA/CaJ)F1 male mice with the nucleoside effectively restored to normal their capacity to generate an antibody response.
Seasonal rhythmicity in lymphocyte blastogenic responses of mice persists in a constant environment.
Authors: Brock M A
Published: December 2022

Young C57BL/6 mice were housed in an environment in which the ambient temperature (22.5 degrees C +/- 1 degree) and photo-period were constant for the duration of the observations. At weekly intervals, animals were sacrificed, and splenic single cell suspensions were tested for percentage of viable cells. The functional capacity of T and B lymphocytes was assessed in vitro by the mitogen-induced incorporation of tritiated thymidine by dividing cells. The lymphocytes were incubated in RPMI 1640 containing 10% fetal calf serum for 68 hr at 37 degrees C. T and B lymphocytes were stimulated with phytohemagglutinin-P and concanavalin A and with lipopolysaccharide, respectively. Seasonal rhythmicity in the incorporation of tritiated thymidine was exhibited by both lymphocyte subpopulations, with peak responses two to five times higher in March to April 1978 and February to March 1979 than during the previous two Decembers. Factors such as birth date of the mice and components of the culture medium had no influence on the results. Because the annual cycles persisted in the absence of known environmental signals or Zeitgebers, they bear similarities with circannual rhythms. It is suggested that a relationship may exist in mice and in other species between seasonally depressed immune functions and increased incidence of infectious agents.
Suppression of T lymphocyte functions by human C3 fragments. I. Inhibition of human T cell proliferative responses by a kallikrein cleavage fragment of human iC3b.
Authors: Meuth J L , Morgan E L , DiSipio R G , Hugli T E
Published: December 2022

Cleavage of human iC3b by kallikrein isolated from human plasma generates a fragment, C3d-K, which is capable of inhibiting mitogen-, antigen-, and alloantigen-induced T lymphocyte proliferation. Native C3, C3a, C3b, and C3c-K had no effect on lymphocyte proliferative responses. In addition to being a potent suppressor of mitogen- and antigen-induced proliferation, C3d-K is capable of inducing leukocytosis in both mice and rabbits. Intravenous injection of C3d-K, but not C3, C3a, C3b, or C3c-K, results in a twofold to threefold increase in the number of circulating leukocytes. Thus, C3d-K exhibits two apparently independent functions, namely suppression of T cell proliferation and leukocytosis. Cleavage of iC3b by kallikrein results in the production of only two fragments. The larger fragment, C3c-K, is 144,000 m.w. and has a chemical structure analogous to that of C3c obtained from the cleavage of C3 by trypsin or elastase. The smaller fragment, C3d-K, is 41,000 m.w. and contains the metastable binding site of C3. It is through this site located in the C3d region of the molecule that C3 attaches covalently to target cells. Analysis of the amino terminal region of C3d-K provided a sequence that fails to overlap with any sequence yet reported for other characterized C3 fragments, including C3d originally obtained from elastase digestion. A revised model of the C3 molecule is proposed, with locations of the C3e and C3d fragments assigned on the basis of chemical analyses.
Blocking of human T lymphocyte functions by anti-Leu-2 and anti-Leu-3 antibodies: differential inhibition of proliferation and suppression.
Authors: Engleman E G , Benike C J , Metzler C , Gatenby P A , Evans R L
Published: December 2022

We have shown previously that monoclonal antibodies to the Leu-2 and Leu-3 T cell antigens block the response of their respective subsets in allogeneic MLR. The present study was an effort to explore the mechanism of inhibition and to determine if anti-Leu-2 and anti-Leu-3 antibodies affect the responses to stimuli in addition to alloantigens. Our results indicate that antibodies to Leu-2 and Leu-3 have profound inhibitory effects on proliferation by their respective T cell subsets responding to a variety of stimuli, including specific soluble antigens and alloantigen. This effect was characterized by the following features: a) For optimal inhibition of proliferation, antibody must be present at the onset of antigenic stimulation. b) Inhibition is augmented by increasing the concentration of antibody or decreasing the concentration of antigen. c) Fab fragments of both anti-Leu-2a and anti-Leu-3a antibodies also block proliferation. In addition to their effects on T cell proliferation, anti-Leu-3 antibody blocked T cell-dependent lg synthesis induced in MLR, and anti-Leu-2 antibody prevented the induction, in vitro, of Leu-2+3- suppressor cells of lg synthesis. Taken together, these results suggest that antibodies to antigenic determinants on the Leu-2 and Leu-3 molecules competitively block segments of these structures that bind to alloantigen or nominal antigen. On the other hand, anti-Leu-2a antibody failed to block suppression of the MLR by in vivo activated, antigen-specific Leu-2+3- suppressor cells, which suggests that the Leu-2a epitope does not transmit antigen-specific signals from these differentiated suppressor T cells.
The complement-mediated binding of soluble antibody/dsDNA immune complexes to human neutrophils.
Authors: Taylor R P , Burge J , Horgan C , Shasby D M
Published: December 2022

The complement-mediated binding of soluble antibody/3H-dsDNA immune complexes (prepared in vitro) to human polymorphonuclear leukocytes (PMN) has been investigated quantitatively. Studies with isolated complement components in conjunction with experiments on the binding of these complexes to human red blood cells suggest that the binding to both cell types is mediated predominantly by CR1 (C4b-C3b) receptors but that CR3 (iC3b or C3d-g) receptors may play a role in binding to PMN but probably not to RBC. Our results also indicate that under the standard conditions of these assays (37 degrees C, 20 to 40 min incubations) there is no significant internalization of the soluble antibody/dsDNA immune complexes after they are bound by the PMN.