bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms of lymphocyte activation: linkage between early protein synthesis and late lymphocyte proliferation.
Authors: Varesio L , Holden H T
Published: December 2022

An experimental model has been developed to study the mechanisms of lymphocyte activation. Using this model we examined the relationship between early protein synthetic events and the late proliferative response to Con A. We found that transient puromycin or cycloheximide-induced inhibition of protein synthesis during the first hour of stimulation by Con A resulted in either inhibition or enhancement of the response, depending on the subsequent treatment of the cells. If the lymphocytes were either not restimulated or restimulated immediately after the initial pulse with metabolic inhibitor plus Con A, there was a decrease in the proliferative response. However, if the cells were restimulated with Con A 24 hr later, there was a shift in the kinetics resulting in a prolonged and increased response. Inhibition of protein synthesis at 6 hr after stimulation with Con A produced no noticeable effects. Hence, there are protein synthetic events that take place during the first hours of stimulation that are critical for the development of the proliferative response. The possibility that these early protein synthetic events are the target for macrophage-mediated regulation of lymphocyte function is discussed.
Identification of a unique idiotype in cerebrospinal fluid and serum of a patient with multiple sclerosis.
Authors: Baird L G , Tachovsky T G , Sandberg-Wollheim M , Koprowski H , Nisonoff A
Published: December 2022

Anti-idiotypic antibodies were prepared in mouse ascites fluid against the CSF-IgG of a patient with multiple sclerosis. After adsorption with pooled human IgG, the ascites fluid antibodies precipitated 20% of labeled autologous CSF IgG. By using a competitive radioimmunoassay, less than one microgram of unlabeled CSF IgG produced 50% inhibition of binding autologous 125I-labeled CSF IgG, whereas 50 micrograms of normal HIgG was not inhibitory. The idiotype could be found in both serum and CSF IgG and persisted over a 5-year period. The absolute concentration of idiotype in the CSF varied somewhat but remained from 4 to 10 times greater than that of the serum. One of 14 heterologous MS CSF was found to contain small amounts of inhibitory protein; eight CSF from patients with other neurologic diseases did not contain the idiotype.
Effects of adriamycin on the activity of mouse natural killer cells.
Authors: Santoni A , Riccardi C , Sorci V , Herberman R B
Published: December 2022

Adriamycin, a widely employed anti-neoplastic agent, was found to have either inhibitory or stimulatory effects on NK activity, depending on the site examined. A single i.p. administration of ADM resulted in a rapid increase of cytolytic activity by PEC of various mouse strains. The effector cells appeared to be NK cells, being nonadherent and nonphagocytic; they expressed low amounts of Thy 1.2 antigen and had the same pattern of specificity as splenic NK cells. In contrast to the stimulatory effects of NK activity of PEC, ADM caused a transient dose-dependent depression of NK activity in the spleen, with a peak reduction at day 3 and recovery within a few days thereafter. The depressed NK activity could be reversed by removal of adherent cells by passage through a nylon column. Moreover, ADM induced cytostatic activity against tumor cells by macrophages, suggesting that activated macrophages may be responsible for suppression of splenic NK activity. The possible modulation of the levels of NK activity by ADM-induced macrophages was supported by mixture experiments, in which plastic adherent spleen cells from ADM-treated mice, but not from normal mice, inhibited the NK activity of normal spleen cells.
Specific spontaneous cytotoxic activity in human T cell colonies.
Authors: Price G B , Teh H S , Miller R G
Published: December 2022

Cells in T cell colonies grown in vitro from normal human peripheral blood leukocytes can kill a variety of different target cells against which the blood donor has not knowingly been previously sensitized, i.e., the colony cells exhibit spontaneous cytotoxicity. Tumor target cells are preferentially killed. The ability to kill two different targets segregates independently in different colonies, which implies that the effector cells are specificity restricted. A majority (perhaps all) of the effector cells possess receptors for sheep erythrocytes and do not possess receptors for the Fc end of IgG, making it unlikely that they are either "natural killer" (NK) cells of cells mediating antibody-dependent cellular cytotoxicity. They may, however, be cytotoxic T lymphocytes.
Anti-self receptors. II. Demonstration of H-2L region-restricted receptors on subpopulations of peripheral T and B lymphocytes.
Authors: Sia D Y , Parish C R
Published: December 2022

Subpopulations of murine spleen, lymph node, and bone marrow cells can bind autologous erythrocytes. The specificity of this interaction was investigated and it was found that these lymphoid cells, like thymocytes, primarily recognize self-H-2L antigens on red cells. Three experimental approaches were used to reach this conclusion: i) The inhibition of autorosetting with erythrocyte sonicates from different H-2 congenic and recombinant mouse strains; ii) the specific blocking of autorosette-inhibition with anti-H-2L antibodies, and iii) the analysis of H-2L mutant mice. The inhibition studies also demonstrated that extrathymic lymphocytes, like thymocytes, carry receptors that can distinguish between b, q and s haplotypes but cannot differentiate between the H-2L molecules expressed by d and k haplotypes. It was found that subpopulations of both T and B lymphocytes autorosette via H-2L restricted receptors. In fact, the majority (80%) of autorosetting cells in spleen were B lymphocytes. Furthermore, the H-2L restricted receptors on B lymphocytes were distinct from surface Ig and could develop in athymic (nude) mice. These findings imply that H-2 restricted receptors on lymphocytes play a much more fundamental and comples role in the immune system than simply directing the interaction of cytotoxic T lymphocytes with target cells.
H-2K/H-2D and Mls and I region-associated antigens stimulate helper factor(s) involved in the generation of cytotoxic T lymphocytes.
Authors: Scott J W , Ponzio N M , Orosz C G , Finke J H
Published: December 2022

This study examines the antigen that stimulate production or release of a soluble helper factor(s) involved in development of cytotoxic T lymphocytes (CTL). Antigens associated with the Mls locus, I and K/D regions of the MHC were all capable of stimulating responder cells in MLC to produce helper factor. These supernatant fluids were all capable of providing "help" for the generation of cytotoxic T lymphocytes in MLC in which spleen cells are stimulated by allogeneic heat-treated thymocytes or splenocytes. Previous reports from our laboratory as well as others have shown that heat-treated cells do not stimulate a cytotoxic response. Heat-treatment of Mls, I, and H-2K/H-2D region incompatible stimulatory cells in MLC eliminated their ability to induce responder cells to produce helper factor, suggesting this is the mechanism whereby heat-treatment reduces the ability of cells to stimulate cell-mediated lympholysis (CML). The inability of supernatant fluids, from MLCs in which heat-treated cells were the stimulators, to assist in the generation of cytotoxic T cells did not appear to be the result of any suppressive factor induced by such treatment. Further, the antigens that stimulate pre-killer cells appear functionally distinct from those heat labile antigens (Mls, I, H-2K/H-2D associated) that stimulate helper factor production since heat-treated allogeneic cells served as stimulators of cytotoxicity provided helper activity was added to the MLC.
Isolation and purification of a type-specific antigen from Chlamydia trachomatis propagated in cell culture utilizing molecular shift chromatography.
Authors: Hourihan J T , Rota T R , MacDonald A B
Published: December 2022

Various techniques have been utilized for antigen solubilization, isolation, and purification. This report is the first to describe the isolation and purification of a type-specific antigen from Chlamydia trachomatis serotype A grown in cell culture. The type-specific antigen was prepared from Chlamydia trachomatis serotype A organisms grown in baby hamster kidney cells (BHK21). The extraction process employed a combination of both pH change and Triton X-100 solubilization. The soluble extract was radioiodinated and subjected to ion exchange and gel filtration chromatography. The fractions eluted were tested for type specificity utilizing the IgG prepared from exhaustively cross-absorbed hyperimmune sera from rabbits immunized with homologous organisms. Molecular shift chromatography was employed for analysis. Small samples of the isolated antigen were later used as markers for preparation of larger quantities necessary for antigenic characterization. The purified type-specific antigen has a m.w. of 30,000 to 32,000.
Mediation of macrophage collagenase production by 3'-5' cyclic adenosine monophosphate.
Authors: McCarthy J B , Wahl S M , Rees J C , Olsen C E , Sandberg L , Wahl L M
Published: December 2022

The production of collagenase by lipopolysaccharide-(LPS) activated guinea pig macrophages is mediated by prostaglandins (PG) of the E series. After stimulation of guinea pig macrophages with LPS, extracellular PGE levels and cellular cAMP levels are elevated. Indomethacin inhibits not only PG synthesis, but also cAMP and collagenase production in LPS-stimulated macrophage cultures. In these indomethacin-inhibited cultures containing LPS, dibutyryl (dB) cAMP, or cholera toxin can restore macrophage collagenase production but not PG synthesis. Moreover, dBcAMP and cholera toxin enhance collagenase production in LPS-activated cultures. Initial activation of the macrophages by an agent such as LPS is a prerequisite for synthesis of collagenase, since in the absence of LPS, dBcAMP or cholera toxin alone are ineffective stimuli. These findings clearly demonstrate a role for PG-induced elevations of cAMP in the production of collagenase by LPS-activated macrophages.
The terminal membrane C5b-9 complex of human complement. Evidence for the existence of multiple protease-resistant polypeptides that form the trans-membrane complement channel.
Authors: Bhakdi S , Tranum-Jensen J , Klump O
Published: December 2022

C5b-9(m) complexes were incorporated into lecithin liposomes and subjected to proteolysis in the presence of DTT to remove the externally oriented annulus. Liposomes were recovered that selectively carried the membrane-bound, thin-walled cylindrical portion of the C5b-9(m) complex. The presence of DTT during proteolysis enhanced peptide bond cleavage in the C5b-9(m) complex. All C5-C9 components were degraded to lower m.w. fragments. A protease-resistant, but hydrophilic 85 to 86,000-dalton polypeptide derivative of C5, possibly representing the C5 beta-chain, was recovered in the fluid phase. This component is not intimately associated with the target lipid bilayer. Immunochemical analyses yielded evidence for the existence of minor C5-C9 antigenic determinants on the membrane-bound C5b-9(m) residue. SDS polyacrylamide gel electrophoreses of liposomes carrying the C5b-9(m) residues revealed the persistence of at least six major polypeptides of approximately m.w. 50,000, 45,000, 40,000, 38,000, 20,000, and 16,000. The data are interpreted to indicate that multiple protease-resistant polypeptide chains derived from several terminal C components participate in formation of the trans-membrane C channel.
Differential allo-response of murine thymocytes to H- 2 K region different recombinants and to H-2Kb mutants.
Authors: Wu S , Bach F H , Sopori M
Published: December 2022

Thymocytes used as responding cells in a mixed leukocyte culture with x-irradiated splenic stimulating cells generate highly significant proliferative and cytotoxic responses when responding and stimulating cells differ by the entire H-2 complex. On the other hand, when the genetic difference between responding and stimulating cells is only a K region, very little, if any, proliferative response is detectable and no cytotoxic response is found. In contrast, when responding and stimulating cell donors differ by a spontaneous mutation in the K region of the H-2 complex, as found in B6.C-H-2ba, B6-H-2bd and B6.C-H-2bf, highly significant proliferative and cytotoxic responses can be obtained. These results, thus, argue that the H-2 mutants cannot, with regard to their relationship to the parental strain, be readily equated with a K region difference as defined in the recombinant inbred strains.
The T lymphocyte proliferative response to poly-L-Glu-poly-D,L-Ala--poly-L-Lys.
Authors: Solinger A M , Schwartz R H
Published: December 2022

The immune response to several antigens has been shown to be under the control of two complementing major histocompatibility-linked immune response (Ir) genes. In most cases, one gene has been mapped to the I-A subregion and the other to the I-E/C subregion. However, in some cases F1 complementation has been described between two alleles in the I-A subregion, so called beta-beta complementation. In these examples, complementation has been seen at the antibody level but not in a T lymphocyte proliferation assay. In the present work, we studied the T cell proliferative response to poly-L-Glu-poly-D,L-Ala--poly-L-Lys (G-A--L). Peritoneal exudate, T lymphocyte-enriched subpopulations (PETLES) from F1 hybrids between C57BL/10 and B10.A, C57BL/10, and B10.A(4R), or B10.A and B10.A(3R) or (5R) mice responded well to G-A--L. In contrast, PETLES from F1 hybrids between C57BL/10 and B10.A(5R) or B10.A and B10.A(4R) mice, as well as from all inbred strains tested, failed to respond to G-A--L. These results demonstrate for the first time an example of Ir gene complementation at the T cell level in which both genes map to the left of the I-J subregion presumably in I-A. This system should now allow us to determine whether alpha-beta and beta-beta complementation take place through the same biologic mechanism.
Glucocorticoids and lymphocytes. II. Cell cycle-dependent changes in glucocorticoid receptor content.
Authors: Crabtree G R , Munck A , Smith K A
Published: December 2022

To study variations in glucocorticoid receptor levels during the cell cycle, we have separated mitogen-stimulated human peripheral lymphocytes and rat lymph node cells by unit gravity sedimentation and measured glucocorticoid binding in the resultant fractions. By morphologic criteria and thymidine incorporation, the fractions were separated into populations of G0 and G1 phase and S and post-S phase cells. A 2- to 3-fold increase in glucocorticoid receptor sites per cell, for cells in the S and post-S phase over those in G0 and G1, was observed with both nonstimulated rat lymph node cell suspensions and concanavalin A-stimulated human peripheral lymphocytes. These observations together with those from other studies indicate that formation of new glucocorticoid receptors near the S phase may be a general phenomenon in proliferating cells. We propose that this increase in glucocorticoid receptors during the cell cycle may explain the increase in glucocorticoid receptors in mitogen-stimulated lymphocytes.
In vitro growth of murine T cells. V. The isolation and growth of lymphoid cells infiltrating syngeneic solid tumors.
Authors: Yron I , Wood T A , Spiess P J , Rosenberg S A
Published: December 2022

A method has been developed for isolating and growing lymphoid cells infiltrating murine solid tumors. When tumor cell suspensions are placed in T cell growth factor (TCGF) lymphoid cells and not tumor cells proliferate. By 7 to 9 days lymphoid cells free of tumor can be harvested and grown continuously in TCGF. The growth of these cells is dependent on the presence of TCGF but not on the presence of concanavalin-A. Tumor cell suspensions that have been freed of T lymphoid cells by treatment with anti-Thy-1.2 serum and complement or by fractionation on Ficoll gradients exhibit no cell out-growth in TCGF. The lymphoid cells growing in TCGF exhibit significant cytotoxicity for syngeneic tumor cells and normal fibroblasts grown in culture but do no lyse normal lymphoid cells.
The first component of complement. I. Purification and properties of native C1.
Authors: Medicus R G , Chapuis R M
Published: December 2022

The first component of complement has been purified by using affinity chromatography on Sepharose-bound IgG. Unlike earlier procedures that yield the activated form of C1, in this method C1 is maintained in the native form by the protease inhibitor p-nitrophenyl, p'-guanidinobenzoate (NPGB). The procedure requires only two steps and yields pure C1 as judged both by SDS-PAGE analysis and by effective molecule calculations. The yields have varied from 30 to 50% in over 50 preparations. The functional properties of the purified native C1 correspond to those of C1 in serum. The dose-response activity profile is nonlinear, but becomes linear when C1 IS ALLOWED TO SELF-ACTIVATE. From SDS-PAGE analysis of the self-activated C1, all the C1r and C1s subcomponents are converted to the activated split products, indicating that all C1 molecules are biologically active. The recovery of C1 activity is dependent on the use of a heterologous source for the IgG on the affinity absorbant. The conditions of binding and elution from the Sepharose-IgG column are critical, indicating that immunoglobulin-bound C1 is rapidly inactivated under physiologic conditions by serum inactivators. The activation of the purified C1 in fluid phase has been explored both in the presence and absence of C1-inhibitor.
Inhibitory factor(s) of lymphoproliferation produced by synovial fluid mononuclear cells from rheumatoid arthritis patients: the role of monocytes in suppression.
Authors: Zembala M , Lemmel E M
Published: December 2022

Synovial fluid (SF) and synovial fluid mononuclear cells (SFM) were obtained from patients with rheumatoid arthritis (R.A.). The SF stimulated normal blood monocytes for nitroblue tetrazolium (NBT) reduction and inhibited normal lymphocyte response to PHA. Similar activities were found in supernatants from the cultures of SFM cells. Molecular weight of the lymphocytes inhibitory factor(s) produced by SFM was in range 50,000 to 100,000. The factor exerted its inhibitory activity via monocytes and had no direct toxic or blocking effect on lymphocytes. Monocytes played an active role in suppression presumably via production of a second-step inhibitory signal(s). It is suggested that the monocytes activated by the SFM-produced factor(s) are in turn triggered on for suppression of lymphoproliferation. These studies implicate that the state of monocyte activation is important in the regulation of lymphocyte responsiveness. This model of suppression may provide some explanation for SF lymphocyte hyporeactivity to mitogens in R.A.
T cell synergy in the rat: serologic characterization of T cell subsets.
Authors: Loop S M , Bernstein I D , Wright P W
Published: December 2022

The W3/25+ T cell subset in rats, defined by a xenogeneic monoclonal antibody and separated by using the FACS, was demonstrated to be the proliferating cell type in the in vitro MLC and to provide an amplifier function for the W3/25- T cell subset in the generation of cytotoxic effector cells to alloantigenic targets.
Regulation of the immune response. II. Characterization of the cell population(s) involved in the Fc fragment-induced adjuvant effect.
Authors: Morgan E L , Thoman M L , Walker S M , Weigle W O
Published: December 2022

Fc fragments derived from human and murine Ig have been shown to possess adjuvant properties. The spleen cell population(s) affected by the Fc fragments is the T lymphocyte. That Fc fragments do not act directly on the B lymphocyte was shown by the fact that in a system where T cell help was substituted for by TRF and using TI antigens, no adjuvant effect was observed. The adjuvant signal provided by the Fc fragments is needed early in the culture period, because it was reduced by approximately 50% when delayed by 24 hr. When the addition of Fc was delayed by 72 hr, the antibody response was not significantly increased over the culture that received antigen only.
Suppression of spontaneous reticulum cell sarcoma development and of syngeneic stimulator cell by anti-mu treatment of SJL/J mice.
Authors: Katz I R , Asofsky R , Thorbecke G J
Published: December 2022

The cellular origin of reticulum cell sarcoma (RCS) in SJL/J mice was studied by comparing the incidence of spontaneous RCS in control mice and in mice suppressed with goat anti-mu Ig from birth on. At 10 months of age anti-mu suppressed mice had 0% RCS as opposed to 60% in control mice. Growth of two i.v. injected transplantable RCS lines in anti-mu suppressed mice was approximately 60% as compared with growth in normal SJL/J mice. Proliferative responses of thymus and lymph node cells from anti-mu suppressed mice to RCS, mitomycin-treated syngeneic spleen cells (M. Spl.) Con A, and PHA were entirely normal. However, M. Spl. from anti-mu suppressed mice caused minimal or no stimulation of T cells from normal or anti-mu suppressed responders. The results suggest that the normal syngeneic stimulator cell is of B cell origin, either representing a direct precursor of RCS or indirectly influencing RCS appearance. A B cell origin of RCS is, furthermore, in agreement with some of its characteristics, such as surface markers (Ia antigens, Ly b) and in vivo localization properties.
Functional characteristics of TG and TnonG cells in a three party MLR.
Authors: Gebel H M , Radaj P A , Holmes D , Schwartz B D , Rodey G E
Published: December 2022

Human peripheral blood T lymphocytes were separated into highly purified Fc gamma receptor-positive (TG) and negative (TnonG) populations. These subgroups were compared with unseparated T cells for their ability to proliferate in response to concanavalin A or allogeneic cells, and to suppress a mixed leukocyte culture reaction (MLR). TG cells fail to vigorously proliferate in response to Con A or irradiated allogeneic cells. Moreover, the response of TnonG populations to Con A and allogeneic cells is enhanced compared with unseparated T cells, suggesting active suppression by TG cells. The suppressive effects of TG cells was confirmed in a 3-party MLR. In contrast, TnonG cells failed to suppress the MLR. However, Con A-activated TnonG cells did suppress the MLR and were as effective as TG cells.
Cell-surface immunoglobulin and insulin receptor expression in an EBV-negative lymphoma cell line and its EBV-converted sublines.
Authors: Spira G , Aman P , Koide N , Lundin G , Klein G , Hall K
Published: December 2022

Membrane Ig and insulin receptors were assayed in the EBV-negative Ramos lymphoma line and its EBV-converted sublines by surface fluorescence. 125I-protein A-binding assay, immunoprecipitation, and insulin receptor assay. The original Ramos line expressed surface IgM but not IgD and had a low concentration of insulin receptors. Ten of 10 converted lines expressed IgD and a variable but usually high insulin-binding capacity. Molecular weight analysis of immunoprecipitated Ig showed the presence of 2 mu-chains and 2 delta-chains. One of each heavy chain type could be characterized as membrane Ig, whereas the other was cytoplasmic. Antisera against the lambda-chain precipitated mu and delta heavy chains as well, indicating that the delta-chain expressed on the membrane of the EBV-converted Ramos lines is bound to the lambda light chain. The results show that the differentiation of a Burkitt lymphoma line is not completely "frozen" and can be induced to change in a more "activated" direction by EBV conversion.
Idiotypic analysis of anti-GAT antibodies. VIII. Comparison of interstrain and allotype-associated idiotypic specificities.
Authors: Ju S T , Pierres M , Germain R , Benacerraf B , Dorf M E
Published: December 2022

A guinea pig anti-idiotypic antiserum made against pooled specifically purified A/J anti-GAT antibodies was characterized. This antiserum contains anti-idiotypic antibodies specific to interspecies, interstrain, and allotype-linked idiotypic determinants. These idiotypic determinants are associated with the combining sites of idiotypic antibodies that are induced by GT-related but not GA-related antigenic moieties. Genetic and strain distribution studies indicated that the shared allotype-linked idiotypic determinants are controlled by Igh-1e- or Igh-1b-linked genes. The interrelationships of the allotype-linked and interstrain CGAT idiotypic specificities are described using monoclonal anti-GAT hybridoma antibodies. Four of 7 hybridoma anti-GAT antibodies of C57BL/6 origin expressed a major fraction of the idiotypic specificities of A/J anti-GAT antibodies. These 4 hybridoma antibodies also carried the common interstrain idiotype, termed CGAT, but not all CGAT-bearing anti-GAT hybridoma antibodies expressed the allotype-linked idiotypic specificities. The Ig-1b-positive, F17-167.1 hybridoma anti-GAT antibody was used as a ligand to selectively identify the major allotype-linked idiotypic specificities, which were designated Gte idiotype.
Idiotypic analysis of anti-GAT antibodies. IX. Genetic mapping of the Gte idiotypic marker within the Igh-V locus.
Authors: Ju S T , Dorf M E
Published: December 2022

The gene controlling the expression of the murine Gte idiotype marker was mapped within the Igh-V gene complex. This idiotypic marker was identified in B6, C.B-20 and A/J and C.AL-20 anti-GAT antisera, but either was not detectable or was present in very low quantities in the anti-GAT antisera obtained from BALB/c, BAB-14, SM/J, NZW, and NZB mice. The data are consistent with the interpretation that the latter 5 strains do not process Igh-Gte genes and the Igh haplotypes of these strains represent examples of crossing over within the Igh complex. Furthermore, the expression of the Gte idiotype(s) is not influenced by the Lyt-3 linked genes that control the kappa light chain polymorphism. Segregation analysis with 52 recombinant inbred strains confirmed the close linkage of Igh-Gte idiotype with Igh-1b locus. The recombination frequency between these loci was calculated to be 1 +/- 0.7 percent. Furthermore, by using B X D recombinant inbred strains, the Igh-Gte gene was mapped within the Igh-V region gene closely linked to the Igh-Np, Igh-Nbp, and Igh-BgI genes.
Distinct phenotypic expression of immunogenicity and immunosensitivity in sublines of a tumor.
Authors: Greenberg P D , Cheever M A , Fefer A
Published: December 2022

Continuous in vitro or in vivo passage of a BALB/c leukemia has resulted in generation of 2 immunologically distinct sublines. The subline maintained by in vitro passage failed to stimulate an allogeneic response but was susceptible to lysis by alloreactive cytotoxic cells. Conversely, the subline maintained by in vivo passage induced an allogeneic response but was resistant to lysis by cytotoxic T lymphocytes (CTL) reactive to H-2d antigens. Resistance to lysis occurred despite expression of H-2d antigens in a form recognizable by differentiated alloreactive CTL, as determined by cold-target inhibition experiments. Moreover, resistance was immunologically specific, in that the subline was susceptible to immune lysis mediated through recognition of other determinants. The results imply that the display and/or orientation of antigen in the cell membrane of these sublines that is required for a lytic event is distinct from the antigen expression necessary for immunologic recognition.
Macrophages in resistance to rickettsial infections: characterization of lymphokines that induce rickettsiacidal activity in macrophages.
Authors: Nacy C A , Leonard E J , Meltzer M S
Published: December 2022

Lymphokine-rich culture supernatants of antigen- or mitogen-stimulated spleen cells were fractionated by Sephadex G-200 column chromatography; fractions were assayed for capacity to induce tumoricidal and rickettsiacidal activities in mouse macrophages. Lymphokine activity that activated macrophages for tumor cytotoxicity eluted as a single peak in the 45,000 m.w. region. In contrast, activity for intracellular killing of rickettsiae eluted in 3 distinct regions: 115 to 125,000, 35 to 45,000, and less than 10,000 daltons. This elution pattern was observed with both antigen and mitogen-induced lymphokines. Activity of each of the 3 lymphokine species for induction of rickettsiacidal activity was destroyed by heating at 56 degrees C for 1 hr. Tumor cytotoxicity and rickettsiacidal activity, both effector functions of activated macrophages, were dissociated on the basis of lymphokines regulating these activities.
Immune response to acute virus infection in the Syrian hamster. II. Studies on the identity of virus-induced cytotoxic effector cells.
Authors: Nelles M J , Duncan W R , Streilein J W
Published: December 2022

The identity of the effector cell(s) mediating vaccinia virus-induced cytotoxic activity in Syrian hamsters undergoing acute virus infection has been investigated. Two different approaches have been utilized in this regard. Although T cells do not mediate vaccinia virus-induced cytotoxic activity directly, studies employing adult thymectomized, x-irradiated, bone-marrow-reconstituted hamsters lacking discernible T cell reactivity demonstrated that the presence of an intact thymus and/or functional T cells were required for the in vivo development of a significant portion of vaccinia virus-induced cytotoxic activity. In addition, incorporation of aggregated gamma-globulins as well as anti-immunoglobulin reagents into the in vitro 51Cr release assay inhibited a significant proportion of the cytotoxic activity mediated by spleen cells obtained from acutely infected hamsters possessing an intact thymus. Both approaches have yielded information consistent with the idea that a sizable portion of vaccinia virus-induced cytotoxic activity in the Syrian hamster is effected by K cells mediating antibody-dependent cell-mediated cytotoxicity (ADCC). The significance of this observation is discussed with regard to hamster viral immunity in general.
Antigen-binding diversity and idiotypic cross-reactions among hybridoma autoantibodies to DNA.
Authors: Andrzejewski C , Rauch J , Lafer E , Stollar B D , Schwartz R S
Published: December 2022

Hybridoma anti-DNA antibodies produced by clones derived from fusions of spleen cells from unimmunized MRL/l mice with BALB/c plasmacytomas were examined for their binding to nucleic acid antigens and for their reactivities with anti-idiotype antibodies. All the antibodies bound to a variety of nucleic acids and polynucleotides. This finding suggests that epitopes shared by nucleic acid antigens can account for some of the serologic diversity in lupus serum. Each hybridoma autoantibody had a unique pattern of reactivity with nuclei acid antigens, yet cross-reactions among some of them were found by analyses with anti-idiotype antibodies. These cross-reactions were due to similarities in the antigen-binding regions of the autoantibodies because anti-idiotype Ig blocked the binding of the hybridoma antibody DNA; moreover, polynucleotides inhibited the idiotype anti-idiotype reaction. Cross-reactive idiotypes were found not only among hybridoma anti-DNA antibodies produced by clones derived from the same MRL/l mice but also among antibodies produced by clones derived from different MRL/l mice. The latter finding suggests that families of germ line genes may encode some autoantibodies against DNA.
Isolation of C4-binding protein from guinea pig plasma and demonstration of its function as a control protein of the classical complement pathway C3 convertase.
Authors: Burge J , Nicholson-Weller A , Austen K F
Published: December 2022

A decay-accelerating factor of the classical complement pathway C3 convertase, C4b,2a, has been purified to homogeneity from guinea pig plasma by a 5-step procedure that includes 5% polyethyleneglycol-4000 (PEG-4000) precipitation, Sepharose 6B gel filtration, heparin-Sepharose chromatography, DE-52 anion exchange chromatography, and Sepharose-C4gp affinity chromatography. The protein elicited a monospecific antiserum in a rabbit and was found with the Mancini technique in both normal and C4-deficient guinea pig plasma at a concentration of 60 microgram/ml. The purified protein gave a single stained band of 550,000 m.w. on SDS-PAGE under nonreducing conditions and a single band of 72,000 m.w. with reduction and alkylation. On the basis of its m.w. and subunit structure, ability to bind to a C4 affinity column, and ability to regulate the classical C system by accelerating the decay of the classical C3 convertase this protein represents the guinea pig analog of the human C4-binding protein.
The role of sialic acid in the functional activity and the hepatic clearance of C1-INH.
Authors: Minta J O
Published: December 2022

The immunochemical properties, catabolic clearance, and organ distribution of highly purified radiolabeled human C1-INH were studied after treatment with glycosidases. The antigenicity and C1s inhibitory activity of C1-INH were unimpaired after removal of sialic acid residues (60%) or sialic acid and galactose residues (60 and 20%, respectively) with immobilized neuraminidase and beta-galactosidase. Treatment of C1-INH with neuraminidase was associated with increased cathodal migration of the glycoprotein. In vivo studies in the rabbit, however, showed that removal of sialic acid residues resulted in rapid blood clearance of C1-INH and enhanced localization of the asialo C1-INH in the liver. Subsequent removal of penultimate galactose residues returned the survival time in the circulation and organ distribution to near normal. Additionally, simultaneous infusion of asialo-C1-INH with asialo alpha 1-acid glycoprotein, a protein known to bind to hepatic asialoglycoprotein receptors, dramatically extended the intravascular survival time of asialo C1-INH. In agreement with the observations on other plasma glycoproteins, these results indicate that desialylation of C1-INH results in rapid clearance by hepatic asialoglycoprotein receptors.
Monoclonal antibodies to mouse MHC antigens. III. Hybridoma antibodies reacting to antigens of the H-2b haplotype reveal genetic control of isotype expression.
Authors: Ozato K , Sachs D H
Published: December 2022

Eleven hybridoma antibodies directed against mouse major histocompatibility complex products of the H-2b haplotype have been produced and characterized. Of 7 antibodies reacting to H-2Kb and/or H-2Db antigens, all cross-reacted with other H-2 antigens, and 5 exhibited no correspondence with a known H-2 specificity established in the H-2 chart. Four anti-Iab antibodies all reacted with antigens encoded by the I-A subregion. Some of these antibodies showed no cross-reaction with other haplotypes, indicating reactions to private specificities of the I-Ab antigen. In addition, these anti-Ia antibodies appeared to be capable of distinguishing fine determinant differences, which corresponding alloantisera failed to reveal. A high frequency of hybridomas secreting IgM antibodies was found after fusions of spleen cells obtained from C3H anti-C3H.SW immunized mice, in contrast to the dominance of IgG hybridomas produced previously by fusions of spleen cells from mice immunized in the reverse direction. An isotype analysis of conventional cytotoxic alloantisera from the same strain combinations was therefore performed. The same correlation with respect to isotype expression was found, indicating that hybridoma antibodies reflect normal antibody responses and suggesting H-2-linked control of this expression.
Antigen-specific clones of proliferating T lymphocytes. I. Methodology, specificity, and MHC restriction.
Authors: Sredni B , Tse H Y , Chen C , Schwartz R H
Published: December 2022

In this report we describe in detail a new method for cloning antigen-specific, proliferating T lymphocytes directly from primed murine lymph nodes after 3 days of activation in vitro. After expansion in liquid culture the cells from the colonies were shown to be antigen specific and to require I-A histocompatible, irradiated spleen cells for stimulation. For hapten-carrier-type antigens, the T cells were shown to be carrier specific in their recognition but they were also capable of distinguishing the presence of the hapten. Recloning of small numbers of these cells in soft agar under conditions of high plating efficiency yielded true clones (i.e., populations derived from a single cell) whose antigen specificity was identical to that of cells from the original colony. The fact that a clone of T cells was I-A restricted in its antigen recognition demonstrates that suppressor T cell function cannot account for the phenomenon of major histocompatibility complex restriction.
Cross-reaction of a rat-anti-mouse phagocyte-specific monoclonal antibody (anti-Mac-1) with human monocytes and natural killer cells.
Authors: Ault K A , Springer T A
Published: December 2022

A monoclonal antibody produced by a hybridoma cell line that has previously been shown to recognize an antigen present on murine macrophages and granulocytes (Mac-1) has now been shown to bind to human monocytes and polymorphonuclear leukocytes. Human monocytes bind about 40,000 M1/70 (anti-Mac-1) F(ab')2 or IgG molecules per cell in saturating conditions. In addition, M1/70 antibody recognizes a small population (less than 10%) of human blood lymphocytes. These cells express approximately 3-fold fewer Mac-1 antigen determinants than monocytes. Separation of this lymphocyte subset on a fluorescence-activated cell sorter has shown that all the natural killing activity in human blood can be found among these cells. Similarly, separation of the natural killer cells by an independent method based on their surface Fc receptor has shown that nearly all of them can be labeled by the hybridoma antibody. The same results are obtained when an F(ab')2 fragment of the M1/70 hybridoma antibody is used. The anti-Mac-1 antibody does not interfere with binding to the Fc receptor, nor does it interfere with either natural killing or antibody-dependent cellular cytotoxicity mediated by these cells. We conclude that there is a similar antigenic structure on the surface of murine and human monocytes and granulocytes and that this structure is also found on human natural killer cells.
Human melanoma-associated antigens: role of carbohydrate in shedding and cell surface expression.
Authors: Morgan A C , Galloway D R , Imai K , Reisfeld R A
Published: December 2022

The shedding of 2 tumor-specific glycoprotein antigens from human melanoma cells into spent culture medium was selectively inhibited by nontoxic doses (0.5 microgram/ml) of tunicamycin, an inhibitor of N-asparagine-linked glycosylation. The inhibition of shedding of these 2 antigens with m.w. of 240K and 94K is complete within 24 hr after addition of tunicamycin. During this time interval, our data suggest that these glycosylated cell surface antigens are replaced by their nonglycosylated forms. Removal of tunicamycin or addition of N-acetyl glucosamine restores shedding of these melanoma-associated antigens with initially reduced glycosylation. This same selective inhibition of shedding was observed with cultures adapted to grow in high doses (2.5 microgram/ml) of tunicamycin that otherwise killed > 98% of the cells upon first exposure. In contrast to other glycoproteins found in spent culture medium of melanoma cells, the shedding of melanoma-associated antigens is strictly dependent on glycosylation.
Demonstration of IgG-Fc and C3 receptors on adult Schistosoma mansoni.
Authors: Tarleton R L , Kemp W M
Published: December 2022

Previous studies have indicated that adult schistosomes have an affinity for both IgG and C; however, thorough investigations on the possible presence of receptors for these serum proteins on the adult schistosome tegument have not been attempted. The present study presents evidence for both IgG-Fc and C3 receptors on adult schistosomes. An indirect assay utilizing fluoresceinated Staphylococcus aureus was developed to detect antigen-antibody (Ag-Ab) and antigen-antibody-C (Ag-Ab-C) binding to adult parasites. Detection of Ag-Ab and Ag-Ab-C complex binding was dependent on the presence of a metabolic inhibitor in the incubation mixture presumably to prevent shedding of bound complexes. Ag-Ab complex binding required the presence of an intact Fc on the IgG of the complex and could be partially inhibited by preincubation of parasites in heat-aggregated IgG or an isolated Fc preparation. Binding of Ag-Ab-C complexes was dependent on active C3 in the C source but not on an intact Fc on the IgG of the complex. Ag-Ab-C binding could be blocked by prior incubation of parasites in heat-aggregated IgG-C but not by C alone. Binding of host serum proteins to IgG-Fc and C3 receptors on adult schistosomes may aid parasite survival by helping to prevent immune detection.
Newborn T cell suppression: early appearance, maintenance in culture, and lack of growth factor suppression.
Authors: Hayward A R , Kurnick J
Published: December 2022

Human newborn T lymphocytes suppress the responses of adult lymphocytes to several stimuli, including the T dependent differentiation of adult B cells to plasma cells (PC) by pokeweed mitogen (PWM) stimulation. We tested blood from premature babies to show that the suppressor activity for PWM-induced B cell differentiation appeared by 26 weeks' gestation. Cord blood from full term babies delivered by Caesarean section also suppressed PC differentiation showing that maternal labor is not a prerequisite for suppression. Eleven percent of freshly isolated newborn T cells bore the putative suppressor phenotype OKT 8 and 81% had the putative helper phenotype OKT 4, so the increased suppression and diminished help of newborn T cells was not associated with an imbalance of phenotypic helper or suppressor cells. The function of newborn T cells was further investigated by establishing the cells in continuous culture with T cell growth factors. The polyclonal lines obtained suppressed adult PWM-induced PC differentiation and were inefficient helpers so their functional characteristics appear to be maintained in culture without changes in the balance of help and suppression. PHA-stimulated newborn lymphocytes were themselves efficient producers of T cell growth factors. We conclude that newborn T cells can suppress without lectin activation and that the suppressor activity that is found is a stable intrinsic characteristic of the cell.
Tumor-associated antigens in spent medium of human melanoma cells: immunochemical characterization with xenoantisera.
Authors: Galloway D R , McCabe R P , Pellegrino M A , Ferrone S , Reisfeld R A
Published: December 2022

Xenoantisera to human melanoma cells and to partially purified melanoma-associated antigens were coupled to protein A-bearing Staphylococcus Aureus or protein A-Sepharose and used as immunoadsorbents for the indirect immunoprecipitation of intrinsically radiolabeled proteins released into culture medium from various cultured human tumor and nontumor cell lines. These radiolabeled immunoprecipitates when analyzed by SDS-PAGE revealed highly reproducible molecular profiles of proteins and glycoproteins released by various cultured tumor lines and control cells into their spent culture media. A comparison of molecular profiles together with data indicating the binding specificity of known xenoantisera produced against human melanoma cells or their extracts led to the discovery of 2 macromolecules that are associated with human melanoma cells; a glycoprotein with a subunit m.w. of 240,000 (240K) and a single-chain glycoprotein of 94,000 (94K) m.w. also found in association with human carcinoma cells are described in this report.
Properties of a minor cross-reactive idiotype associated with anti-p-azophenylarsonate antibodies of A/J mice.
Authors: Gill-Pazaris L A , Lamoyi E , Brown A R , Nisonoff A
Published: December 2022

Experiments are described that further characterize an A/J anti-phenylarsonate (anti-Ar) antibody population, which is idiotypically cross-reactive within the strain but differs from the family of antibodies expressing the major cross-reactive idiotype (CRI). This population has been designated as expressing a "minor" cross-reactive idiotype. Chain recombination studies with hybridoma products (HP) revealed that 2 of 3 HP expressing minor idiotypic determinants contain L chains that are idiotypically closely related to L chains in anti-Ar antibodies bearing the major CRI. The results indicate the expression of the same or very similar L chains in antibodies that differ in idiotype. The minor idiotypic population in serum was investigated by separating antibodies with minor and major idiotypic determinants by use of an immunoadsorbent containing anti-idiotype directed to an HP expressing the major CRI. Studies with the nonadherent, minor idiotypic population showed that such molecules constitute about 8 to 10% of the anti-Ar antibodies in a pool of serum but that individual sera vary markedly in their content of anti-Ar antibodies bearing minor idiotypes. Preinoculation of mice with conventional anti-idiotypic antiserum before immunization with KLH-Ar was found to suppress the appearance of the minor idiotypes as well as the major CRI upon subsequent immunization. The suppression of the minor idiotypic population is presumably mediated by the small fraction of rabbit anti-id antibodies directed against such molecules.
Immunogenicity of haptenated schistosomula in vitro.
Authors: Abbas A K , James S L , Sher A
Published: December 2022

Skin-stage schistosomula of Schistosoma mansoni modified with 2,4,6-trinitrophenyl (TNP) induce primary anti-TNP plaque-forming cell (PFC) responses in normal mouse spleen cells in vitro. The PFC are TNP-specific, and the response is dependent on adherent cells and T lymphocytes. In contrast, comparably haptenated lung stage larvae are weakly or nonimmunogenic in this system, and their inability to stimulate anti-TNP PFC cannot be attributed to a toxic or suppressive effect. These observations suggest that maturation of schistosomula in vivo is accompanied by a decline in their immunogenicity, which, along with other adaptive mechanisms, may promote the survival of parasites in the host environment.
A mechanism of migration inhibition in delayed-type hypersensitivity reactions. II. Lymphokines promote procoagulant activity of macrophages in vitro.
Authors: Geczy C L , Hopper K E
Published: December 2022

Although lymphokine supernatants had no procoagulant activity per se, guinea pig peritoneal exudate cells (PEC), incubated with lymphokine supernatants or with a lymphokine fraction of 35,000 to 50,000 daltons decreased the recalcification time of platelet-poor plasma. PEC from animals immunized with BCG or with ovalbumin and incubated with the corresponding antigen had increased procoagulant activity. Similar effects were observed with PEC incubated with endotoxin. The induction of procoagulant activity by the cells was accompanied by a concomitant decrease in their ability to respond to chemotactic agents and to migrate from capillary tubes. Separation of exudate cells by sedimentation velocity indicated that large macrophages had the highest degree of procoagulant activity after incubation with lymphokines. The clotting time of Factor IX-deficient plasma was decreased by lymphokine-treated macrophages, indicating that the extrinsic clotting sequence may be activated as a result of increased tissue factor on the treated cells. Heparin abolished the ability of lymphokines to inhibit macrophage migration.