bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity of Long-Standing Xenografts of Rat Hearts to Humoral Antibodies
Authors: Burdick James F. , Russell Paul S. , Winn Henry J.
Published: December 2022

Long-standing rat skin xenografts on immunosuppressed mice are known to become insensitive to destruction by mouse anti-rat serum. Our present experiments demonstrate that long-standing primarily vascularized rat-to-mouse cardiac xenografts, unlike skin, remain fully sensitive to antiserum-mediated destruction, even in mice also bearing a long-standing skin graft that is resistant to antiserum. It appears that skin grafts become resistant to antiserum-mediated destruction because of extensive replacement of the endothelium by cells of host origin. The hearts remain sensitive to anti-serum since such an extensive endothelial replacement would not occur as readily in these whole organ grafts.
Physicochemical and Functional Identity of Rabbit Platelet-Activating Factor (PAF) Released in Vivo during IgE Anaphylaxis with PAF Released in Vitro from IgE Sensitized Basophils
Authors: Neal Pinckard R. , Farr Richard S. , Hanahan Donald J.
Published: December 2022

Platelet activating factor (PAF) released in vivo into the plasmas of rabbits during development of IgE-induced systemic anaphylactic shock had indistinguishable physicochemical and functional properties when compared with PAF released in vitro from antigen-stimulated, washed buffy coat cells containing IgE-sensitized basophils. Our findings represent the first documentation for the release of PAF in vivo and strongly support its role as an important chemical mediator involved in acute inflammatory reactions and tissue injury. The intravascular release of PAF during IgE anaphylaxis correlated temporally with the development of intravascular platelet aggregation and the development of thrombocytopenia and neutropenia. Passive transfer experiments indicated that IgE-sensitized basophils alone can initiate the intravascular release of PAF and development of the various platelet and neutrophil alterations similar to those observed during the anaphylactic syndrome in the actively immunized rabbit.

The PAF released in vivo or in vitro was completely recoverable by chloroform-methanol-water extraction and was easily and completely phased into a chloroformrich layer after the addition of water. All of the PAF samples studied consistently migrated on thin layer chromatography as a sharp band between sphingomyelin and lysolecithin on silica gel G plates by utilizing a solvent system of chloroform-methanol-water, 65:35:4, v/v. The mobility of the PAF on thin layer chromatography was essentially unaffected when chloroformmethanol-acetic acid-water, 25:15:4:2, v/v, or chloroform-methanol-25% ammonia 65:35:4, v/v, were utilized as the solvent systems. These observations, coupled with the fact that PAF preparations could not be extracted from the chloroform solution with NaHCO3 argue for a neutral lipid molecule. Functional PAF activity and migratory properties on thin layer chromatography were stable to acid conditions, exposure to air, treatment with periodic acid or sodium nitrite, but were exquisitely labile to methanolic NaOH. The above characteristics would eliminate the occurrence of a structure containing a vinyl ether linkage, a free glycerol, glycol or sugar moiety, but would support a neutral polar lipid containing a fatty acid ester group.
Stability of DNA/anti-DNA complexes. II. Salt lability and avidity.
Authors: Riley R L , Addis D J , Taylor R P
Published: December 2022

The kinetics of dissociation of antibody-radiolabeled dsDNA (homogeneous PM2 DNA or sonicated dsDNA of m.w. 6 x 10(5)) complexes at 37 degrees C have been examined via three independent radioimmunoassays: the Farr, Millipore Filter, and PEG assays. Two different procedures were used to study the kinetics. Either excess unlabeled DNA or high salt concentrations were employed to induce complex dissociation. Our results suggest that typical SLE sera contain at least two distinct populations of anti-dsDNA antibodies. One population is of rather high avidity and dissociates slowly in the presence of excess DNA or high salt. The other population is of considerably lower avidity and is dissociated more rapidly under these conditions. The results of a double label dissociation kinetics study provide independent evidence supporting this hypothesis.
The self determinants recognized by human virus-immune T cells can be distinguished from the serologically defined HLA antigens.
Authors: Biddison W E , Ward F E , Shearer G M , Shaw S
Published: December 2022

The self specificity of human influenza virus-immune cytotoxic T cells has been analyzed in order to clarify the relationship between the self antigens that they recognize and the serologically defined HLA-A and -B antigens. Virus-immune effectors from HLA-A2-positive donors were tested on panels of virus-infected target cells from donors who were either HLA-mismatched or matched only for HLA-A2. Virus-immune T cells from 11 out of 11 A2-positive donors lysed all A2-matched virus-infected target cells (and no HLA-mismatched targets), except that each of these effector cells consistently failed to lyse virus-infected target cells from one A2-positive donor (designated M7). Although the A2 specificity of donor M7 could also be distinguished from the A2 antigen of other donors by alloimmune cytotoxic T cells, no differences in the A2 antigen of donor M7 could be defined by extensive serologic analyses. These results indicate that there is a strong but incomplete association between a self antigen recognized by virus-immune T cells and the serologically defined HLA-A2 specificity.
Polyclonal activation of human lymphocytes in vitro-II. Reappraisal of T and B cell-specific mitogens.
Authors: Dosch H M , Schuurman R K , Gelfand E W
Published: December 2022

The capacity of the T cell mitogens phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM), and Staphylococcus protein A (SpA) to induce B cell proliferation and differentiation was compared with the B cell mitogen, formalinized Staphylococcus aureus (STA). Lymphocyte subpopulations from normal donors and patients with various immunodeficiency diseases were studied. In the presence of the T cell mitogens, irradiated T cells were capable of providing a helper cell activity that enabled co-cultured B lymphocytes to proliferate in response to these mitogens and to differentiate into IgM-secreting (direct) hemolytic plaque-forming cells (PFC). In the PFC response, radioresistant T-helper and radiosensitive T-suppressor cell activities could be demonstrated. T-suppressor cell activity outweighed helper activity only in nonirradiated co-cultures stimulated with Con A. Patients with severe combined immunodeficiency lacked mitogen-induced helper T cells, whereas patients with various forms of humoral immune deficiency were normal in this respect. These findings and the tissue distribution of the helper activity is aquired early in post-thymic T cell differentiation. The data suggest that experiments with cell lineage-specific lymphocyte mitogens should be considered in the context of more complex cell-cell interactions.
Evidence for the absence of I-E/C antigen expression on the cell surface in mice of the H-2b or H-2s haplotypes.
Authors: Ozato K , Lunney J K , El-Gamil M , Sachs D H
Published: December 2022

Mouse Ia antigens encoded by I-E/C subregions of the H-2b and H-2s haplotypes have not previously been detected with alloantisera. We have therefore examined the reactivity of xenoantisera, which could potentially detect nonpolymorphic determinants of these antigens, by using a sequential immunoprecipitation analysis of internally labeled glycoproteins from spleen lymphocytes of H-2b and H-2s haplotypes. The first xenoanti-serum, BN rat anti-B10 (H-2b) mouse, contained anti-Ia reactivity but precipitated only I-A antigens from both H-2b preparations and from preparations of another haplotype (H-2a) that is known to express I-E/C alloantigens. The second xenoantiserum, goat anti-Ia, was raised against soluble Ia antigens of H-2d haplotype. This serum lysed lymphocytes of all H-2 haplotypes tested and precipitated both I-A and I-E/C antigens from H-2d antigen preparations. However, when b or s haplotype antigens were examined, this antiserum precipitated only I-A antigens. These observations favor the hypothesis that I-E/C antigens are not expressed in these haplotypes. This hypothesis offers a possible explanation for the broad interspecies cross-reactions of anti-I-E/C alloantisera raised in either H-2b or H-2s haplotypes and may have implications for studies of two-gene control of immune responses.
Release of an endogenous pyrogen from guinea pig leukocytes: the role of T lymphocytes and correlation with suppression (desensitization) of delayed hypersensitivity.
Authors: Atkins E , Askenase P W , Francis L , Bernheim H A
Published: December 2022

The pathogenesis of fever in delayed hypersensitivity (DH) was studied in guinea pigs immunized with either ovalbumin or bovine gamma-globulin in complete Freund's adjuvant. In vitro incubation of sensitized lymphocytes with the specific antigen used for immunization resulted in the elaboration of a lymphokine-like factor that activated either monocytes or neutrophils to release endogenous pyrogen (EP), the protein that causes fever. Specifically sensitized T cells appeared to be responsible for release of this EP-inducing factor. Desensitization of the dermal DH response to antigen was produced by several large injections of antigen and was associated with a reduced capacity of lymphocytes from such animals to activate phagocytic cells to release EP. This may explain the reduced fever (pyrogenic tolerance) that occurs when repeated injections of antigen are given to sensitized animals. Fever and the dermal response to DH seem to be closely linked reactions that have evolved to defend the host against invading pathogens. In both reactions, phagocytic cells appear to be activated by lymphokines derived from T lymphocytes specifically responding to microbial antigens.
Induction and regulation of immunoglobulin expression in a murine pre-B cell line, 70Z/3. I. Cell cycle-associated induction of sIgM expression and kappa-chain synthesis in 70Z/3 cells by LPS stimulation.
Authors: Sakaguchi N , Kishimoto T , Kikutani H , Watanabe T , Yoshida N , Shimizu A , Yamawaki-Kataoka Y , Honjo T , Yamamura Y
Published: December 2022

Stimulation of a murine pre-B cell line, 70Z/3, with LPS induced sIgM expression and an increase of L kappa-chain mRNA within 12 hr. In synchronized 70Z/3 cells, the cell division cycle was 10 to 11 hr and LSP-stimulation did not affect the cell division cycle. LPS-signals given at G1/S boundary induced sIgM expression in the G2 to M-phase. On the other hand, LPS-signals given after M-phase did not induce sIgM expression. Inhibition of cell division with demecorcin did not affect sIgM expression in the M-phase. Induction of intracellular kappa-chain synthesis was also observed in the G2 to M-phase when the LPS-stimulation was provided at G1/S boundary, but LPS-signals given after the M-phase did not induce de novo synthesis of kappa-chain. These results showed that LPS-induced sIgM expression and synthesis of kappa-chain were cell cycle-related events and sIgM expression was associated wih de novo synthesis of kappa-chain.
Generation and release of platelet-activating factor (PAF) from enriched preparations of rabbit basophils; failure of human basophils to release PAF.
Authors: Betz S J , Lotner G Z , Henson P M
Published: December 2022

Rabbit mononuclear cells containing up to 20% basophils and uncontaminated by neutrophils release PAF when stimulated with goat antiserum to rabbit IgE. The amount of PAF detected was a function of basophil concentration but decreased on a per cell basis at high basophil or high total cell concentrations. Calcium ionophore A23187, but not protein A, C5a, or FMLP, initiated rabbit basophil degranulation and PAF release. By contrast, extensive studies using a variety of human leukocyte preparations failed to demonstrate the release of significant levels of PAF from human basophils by IgE-dependent or -independent mechanisms. These results suggest that cells other than the peripheral blood basophil (e.g., the neutrophil) may act as the primary site of PAF production in man.
Cytotoxic activity and interferon production by lymphocytes from patients with multiple sclerosis.
Authors: Santoli D , Hall W , Kastrukoff L , Lisak R P , Perussia B , Trinchieri G , Koprowski H
Published: December 2022

Peripheral blood lymphocytes from MS patients and from healthy control donors were compared for their ability to mediate spontaneous and antibody-dependent cell-mediated cytotoxicity. They were also compared for their ability to respond to infection with various strains of measles and sSPE viruses with interferon production and enhanced NK activity. Neither SLMC nor ADCC against several different target cells was found to be impaired in the MS population. Furthermore, no defect was detected in the response of patients' lymphocytes to virus challenge in vitro in terms of both activation of NK cells and interferon production. Enhanced NK activity was also induced by an exogenous interferon preparation and by Poly I:C to the same extent in patients and controls.
The biologic activity of the immunoregulatory lipoprotein, LDL-In is independent of its free fatty acid content.
Authors: Curtiss L K , Edgington T S
Published: December 2022

The immunoregulatory normal plasma lipoprotein subclass, termed LDL-In, suppresses a number of immune responses in vitro including peripheral blood lymphocyte phytohemagglutinin-stimulated 3H-thymidine uptake, pokeweed mitogen-driven immunoglobulin synthesis, and the generation of cytolytic T cells. In vivo parallels have also been demonstrated. Plasma lipoproteins represent noncovalent complexes of lipid and apolipoprotein chains. Since free fatty acids have been demonstrated to suppress certain lymphocyte responses including mitogen-stimulated 3H-thymidine uptake, we have examined the hypothesis that the free fatty acids associated with LDL-In particles are the biologically active constituents. However, the dose-dependence and the kinetics of LDL-In-mediated suppression were distinctly different from those observed for a number of free fatty acids. In addition, when greater than 92% of the endogenous free fatty acids of LDL-In were removed by incubation in the presence of delipidated albumin, no differences were observed between this free fatty acid depleted LDL-In and native LDL-In with respect to suppressive activity for lymphocyte stimulation or binding to the lymphocyte LDL-In receptor. These observations indicate that the interaction of the LDL-In particle with the lymphocyte receptor and the suppression of lymphocyte function are independent of the free fatty acid content of this bioregulatory lipoprotein, thus focusing attention on the apolipoprotein chains or the phospholipids and glycolipids of this minor plasma lipoprotein.
Immune response to phosphorylcholine. VIII. The response CBA/N mice to PC-LPS.
Authors: Köhler H , Smyk S , Fung J
Published: December 2022

CBA/N mice and F1 crosses of CBA/N X BALB/c with the CBA/N phenotype respond to immunization with PC-LPS with a PC-specific and an anti-bridge antibody production. The PC-specific response in defective CBA/N and NBF1 is devoid of the IgG3 subclass and is not T15 idiotype dominant, whereas normal BALB/c and nondefective NBF1 mice express the T15 dominantly in their anti-PC-LPS response. By the criteria of responsiveness to PC-LPS only and the absence of dominant T15 expression, the precursors in defective NBF1 mice for TI-1 antigen PC-LPS can be characterized as being immature B cells similar to those found in neonatal livers of normal BALB/c or in spleens of chronically idiotype suppressed BALB/c mice. This analogy suggests that the developmental defect in CBA/N mice becomes active during the maturation process before selection for clonal dominance occurs and specialization of precursors for the preferred expression of the IgG3 subclass is completed. Alterations in the T cell compartment may contribute to the immature nature of B cells in the sex-linked immunodeficiency of CBA/N mice.
Mechanisms of lymphocyte-mediated cytotoxicity. I. The effects of anti-human lymphotoxin antisera on the cytolysis of allogeneic B cell lines by MLC-sensitized human lymphocytes in vitro.
Authors: Ware C F , Granger G A
Published: December 2022

Goat and rabbit anti-human lymphotoxin sera, IgG and F(ab')2 reagents were investigated for their capacity to effect a specific alloimmune lymphocyte-mediated cytotoxic reaction. The cytotoxic reaction employed human peripheral blood or adenoid lymphocytes sensitized in MLC to allogeneic B lymphocyte cell lines and lysis was measured in a short-term 51Cr-release assay. A polyspecific anti-LT sera (anti-WS), made against unfractionated whole supernatants from lectin-activated lymphocytes and its IgG and F(ab')2 fragments, was found to be a potent inhibitor of this reaction when the anti-WS reagent was present throughout the assay period. Absorption studies indicated the anti-WS was inhibiting cytolysis at the level of effector cell or its products. Two broadly defined antibody specificities were involved in the cytolytic-inhibitory activity of the polyspecific anti-LT; i) antigens present on the normal lymphocyte cell surface; and ii) lymphocyte surface antigens associated with activated cells. These results correlate with the previously defined antigenic structure of the LT Cx and alpha H classes. Anti-LT sera reactive with the smaller m.w. alpha and beta classes and subclasses were not inhibitory, although the anti-beta sera showed a moderate enhancing activity. The results indicated that several anti-LT antibody specificities may be required to inhibit alloimmune cytolysis. The results suggest LT molecules may mediate lymphocyte-induced alloimmune cytolysis as a multi-component toxin system, rather than as an individual toxin.
Immature B cells as the target for in vivo tolerance induction.
Authors: Klinman N R , Schrater A F , Katz D H
Published: December 2022

In vitro studies have indicated that immature B cells at a specific stage in clonal maturation are exquisitely susceptible to tolerance induction by antigens and antigen concentrations that have no effect on mature B cells. In order to determine if a similar phenomenon obtains for B cells in vivo, mice were tolerized with DNP-D-GL and their splenic and bone marrow B cells were carefully washed and analyzed for responsiveness in the splenic focus system. The results demonstrate that, whereas the treated mice themselves become rapidly unresponsive to either DNP or TNP on a heterologous carrier, a measurable decrease in the frequency of splenic DNP-responsive B cells occurs only very slowly with a half-life of approximately 2 wk and TNP-responsive splenic B cells are only marginally, if at all, affected. A progressive decrease in DNP-responsive bone marrow B cells is also observed and occurs at a somewhat more rapid rate than the decrease in splenic B cells. The rate of decrease of splenic precursor cells is totally consistent with the normal attrition of mature B cells in the absence of newly generated DNP-specific B cells. Thus, in vivo tolerance, like in vitro tolerance may only eliminate immature B cells as they emerge from their stem cell pool and has no effect on mature resident B cells. This conclusion is consistent with the additional finding that 1 mo after tolerance induction, the majority of remaining DNP-responsive B cells in the bone marrow is found in very early precursors that have not, as yet, acquired their immunoglobulin receptors. Finally, the exquisite specificity of this tolerance induction would be totally consistent with a physiologic role for a clonal abortion mechanism that could specifically eliminate self-reactive B cells while leaving essentially intact the B cell repertoire responsive to non-self determinants.
In vitro growth of cytotoxic human lymphocytes. III. The preparation of lectin-free T cell growth factor (TCGF) and an analysis of its activity.
Authors: Lotze M T , Rosenberg S A
Published: December 2022

Supernatants containing T cell growth factor (TCGF) that are produced by incubating human peripheral blood lymphocytes with the mitogenic lectin, phytohemagglutinin (PHA) have previously been shown to allow the successful culture of antigen-reactive T cells. The continued presence of PHA in these preparations, however, complicates the analysis of the direct effects of TCGF. In this report we describe in detail methods used to remove greater than 99% of the exogenous mitogen with a 77% yield of TCGF. TCGF activity precipitated between 50 and 75% saturated ammonium sulfate and was freed of 90% of exogenous PHA. Residual PHA was removed by absorption on affinity columns of Sepharose 4B linked to rabbit anti-PHA antibody. Ninety-nine percent of PHA was removed by these techniques based on assays of the mitogenesis of fresh lymphoid cells and the use of tracer quantities of highly purified radiolabeled PHA. This partially purified TCGF (PP-TCGF) supported the continued growth of mitogen or alloactivated lymphoid cells but not fresh resting cells unless high starting numbers of lymphoid cells are used. An increase of up to 500 times the number of specific lytic units/culture was obtained by expanding alloactivated cells in PP-TCGF when compared to the crude TCGF supernatants.
Immune restoration and/or augmentation of local xenogeneic graft versus host reaction by Cimetidine in vitro.
Authors: Mavligit G M , Calvo D B , Patt Y Z , Hersh E M
Published: December 2022

The immunorestorative effect of Cimetidine in vitro on the T cell-induced local GVH reaction in vivo was studied in 43 cancer patients and 43 normal healthy donors. Both low dose (10(-5) M) and high dose (10(-4) M) Cimetidine induced significant, albeit partial, immune restoration among GVHR-negative cancer patients (p less than 0.05, p less than 0.01, respectively) with the high dose being significantly more effective (p less than 0.05). In contrast, similar Cimetidine doses induced only moderate augmentation (p greater than 0.05) among GVHR-positive cancer patients and a marginal one among normal healthy donors. In the latter 2 groups, Cimetidine was found to be occasionally detrimental in that it induced a conversion from a positive to a negative GVH reaction. These results support the concept of anti-suppressor cell activity ascribed to Cimetidine. However, the possibility of a detrimental effect should be born in mind in planning future clinical trials. We propose that the use of Cimetidine be limited to cancer patients with documented increase in suppressor cell activity associated with defective T cell function under close serial monitoring.
Genes of the H-2 complex regulate the antibody response to murine leukemia virus.
Authors: Vlug A , Schoenmakers H J , Melief C J
Published: December 2022

The influence of the major histocompatibility complex of the mouse (H-2 complex) on the antibody response against murine leukemia virus (MuLV) was investigated after 3 different ways of virus presentation (milk transmission of virus, spontaneous virus activation, and immunization with inactivated virus). The antibody response against MuLV was measured in the sera of H-2 congenic C57BL V+ sublines (V+ denotes positive for milk-transmitted MuLV), (B10.AV+ X C57BL)F1 mice, (C57BL X AKR)F1 mice and of C57BL animals after immunization with inactivated AKR virus. The pattern of immune responsiveness of the different C57BL strains to MuLV was independent of virus replication and was similar for the 3 ways of virus presentation. Serum antibody levels were controlled by 2 genes within the H-2 complex. The first gene (Ir-MuLV-1) was located in the I-A region and was complemented by a second gene (Ir-MuLV-2), which was situated in the regions to the right of the I-B region. Presence of 2 responder alleles (Ir-MuLV-1+,2+) led to an optimal antibody response (H-2b haplotype). Animals that only expressed a responder allele in the I-A region (Ir-MuLV-1+,2-) were intermediate responders. Animals lacking a responder allele in the I-A region (Ir-MuLV-1-,2+ or Ir-MuLV-1-,2-) were low responders.
The third component of complement: covalent attachment of a radioactive sugar to the labile binding site of C3 via the alternative pathway.
Authors: Mann J , O'Brien R , Hostetter M K , Alper C A , Rosen F S , Babior B M
Published: December 2022

A complement- (C) fixing particle consisting of agarose beads to which 5-thioglucose was attached by a --S--S-- bond (agarose-thioglucose) was employed to investigate the mechanism of attachment of C3 to surfaces. When whole serum containing [125I] C3 was incubated with agarose-thioglucose, labeled C3b was taken up in a form that was not removed by 2 M NaCl but was released by 10 mM dithiothreitol. Deposition of DTT-releasable C3b was dependent upon the alternative pathway of C activation. Gel electrophoresis of DTT-releasable C3b from similar experiments performed with unlabeled serum and agarose-[3H]thioglucose showed that the liberated C3b contained a molecule of radioactive thioglucose attached to the alpha'-chain by a covalent bond that was stable to mercaptoethanol. We propose that the thioglucose-alpha' chain bond was formed during the course of C activation by a reaction between the "labile binding site" of newly released C3b and the (then) particle-bound sugar. This formulation implies that the reaction by which C3b attaches to 5-thioglucose in this system is the reaction responsible for opsonization by C3b, and that the C3b-linked sugar represents a marker for the labile binding site. Incubation of the particle-bound C3b in serum resulted in the cleavage of the covalently linked alpha'-chain to several smaller polypeptides, the major cleavage product having a m.w. of 70,000.
T cell subpopulations required for the human cytotoxic T lymphocyte response to influenza virus: evidence for T cell help.
Authors: Biddison W E , Sharrow S O , Shearer G M
Published: December 2022

The requirement for specific T cell subsets in the in vitro generation of human influenza virus-immune cytotoxic T lymphocyte (CTL) responses was investigated. Peripheral blood T cell populations were identified by and selected for their reactivity with the monoclonal antibodies OKT3, OKT4, and OKT8. Influenza virus-immune CTL effectors are OKT3+, OKT4-, and OKT8+. Analysis of CTL precursors demonstrates that: 1) influenza-immune CTL precursors are OKT3+, OKT4-, and OKT8+; 2) CTL precursors require radioresistant OKT3+ helper T cells in order to generate strong cytotoxic responses; and 3) helper T cells can be obtained from either the OKT4+ or OKT4- populations, but more potent help was generated by the OKT4+ subset. The demonstration of a helper T cell requirement for the generation of influenza virus-immune CTL suggests that helper T cells may be involved in the previously documented HLA-linked Ir gene control of influenza-immune CTL responsiveness.
Regulation of antigen-induced lymphoproliferation by BSA gradient-separated T cell fractions.
Authors: Emmons R P , Carvalho E M , Horwitz D A
Published: December 2022

Human T cells from 6 volunteers immunized with keyhole limpet hemocyanin (KLH) or tetanus toxoid were fractionated on bovine serum albumin (BSA) gradients. These T cell fractions were then recombined with autologous unseparated mononuclear cells or unseparated T cells to determine the effect of each fraction on the proliferative (DNA synthetic) response to the immunizing antigen. Using this separation technique, we were able to define 2 fractions of T cells of widely different densities that had a suppressive effect on the proliferative response to KLH of unfractionated T cells. The demonstration of suppressive activity was possible only if cells were tested within 8 wk of immunization with KLH. These suppressive T cell fractions differed not only in density but also in surface characteristics. Fraction 1 cells had a high proportion of Ia+ cells but no Fc receptors for IgG (FcRG-) were seen, whereas cells from fraction 4 (of higher density) were Ia- and were composed of 12.1 +/- 1.2% FcRG+ cells. this suppression was shown to be specific for the immunizing antigen. One individual who had been immunized with KLH for more than 1 yr in which suppression of KLH-induced proliferation was no longer demonstrable was given primary immunization to tetanus toxoid. Suppression could be demonstrated in fractions 1 and 4 specific for tetanus toxoid; there was no demonstrable effect of these T cell fractions on the response to KLH. We postulate that these are different functional populations of suppressor T cells that regulate antigen specific lymphoproliferation.
Activation of antigen-specific suppressor cells in human schistosomiasis mansoni by fractions of soluble egg antigens nonadherent to Con A sepharose.
Authors: Rocklin R E , Tracy J W , El Kholy A
Published: December 2022

The nature of the mononuclear suppressor cell and the fraction of crude soluble egg antigen (SEA) capable of activating antigen-specific suppressor cells were studied in 32 Egyptian children infected with schistosomiasis mansoni. Crude SEA was fractionated on Con A Sepharose, and the unbound and bound material (eluted with alpha-methyl-D-mannoside) was recovered for use in the generation of suppressor cells by the use of a co-culture technique. The glycoprotein fraction was further purified by DEAE cellulose chromatography to isolate the major serologic antigen (MSA-1). We found that both the crude SEA and the "protein" fraction (nonadherent to Con A Sepharose) of SEA was capable of inducing antigen-specific suppressor cell activity in a dose-dependent manner. The glycoprotein fraction of SEA (including MSA-1) was responsible for inducing nonspecific suppression. The antigen-specific suppressor cell was characterized in terms of its adherence properties of plastic and the presence of a receptor for sheep erythrocytes (E). The nonadherent, E-rosette-positive mononuclear cells were found to be activated by the crude SEA, and the "protein" fraction of SEA was found to exert an antigen-specific suppressor influence. Clinically, suppressor cell activity was found to be statistically greater in patients with a high intensity of infection compared to those with a low intensity of infection, but it was not different in patients with regard to the presence or absence of organomegaly. These results provide further information on one of the immunoregulatory mechanisms operative in human S. mansoni infection and on the nature of the antigen(s) that activates this response during the course of infection.
Monomorphic anti-HLA-A,B,C monoclonal antibodies detecting molecular subunits and combinatorial determinants.
Authors: Brodsky F M , Parham P
Published: December 2022

Thirteen monoclonal antibodies that react with monomorphic determinants on the HLA-A,B,C-beta 2-microglobulin (beta 2m) molecule were characterized. Analysis of antibody activity included inhibition by papain-solubilized HLA antigens and free beta 2m, antibody binding to mouse-human somatic cell hybrids containing human chromosome 6 or 15, and antibody cross-reactivity with lymphocytes from nonhuman species. Two criteria for monomorphism were established: 1) equal inhibition or absorption of antibody activity by all papain-solubilized HLA antigens or cell lines of different HLA specificities tested; and 2) nonpolymorphic cross-reactivity within another species or subspecies. On the basis of soluble antigen inhibition and binding to somatic cell hybrids, 3 classes of antibodies were detected: anti-beta 2m, anti-heavy chain, and anti-complex (against a combinatorial determinant formed by heavy chain and beta 2m). Antibody cross-reaction patterns in nonhuman species were suggestive that these monomorphic antibodies detect a limited number of determinants, minimally one on each chain and 2 combinatorial determinants. Examination of the known primary sequences for HLA-A2, HLA-B7, H-2Kb, and mouse, rabbit and human beta 2m provides a molecular explanation for this limited mouse anti-HLA monomorphic antibody activity.
Hapten-coupled monoclonal anti-I-A antibodies provide a first signal for the induction of suppression.
Authors: Bromberg J S , Nepom J T , Benacerraf B , Greene M I
Published: December 2022

A mechanism for induction of hapten-specific immune unresponsiveness is described that utilizes a hapten-conjugated monoclonal anti-Ia antibody to direct the in vivo immune response. Azobenzenearsonate- (ABA) coupled anti-I-Ak antibodies provide a potent first signal for the induction of nonresponsiveness to ABA in H-2k,a mice. The use of an anti-Ia antibody requires haplotype matching and may selectively direct the hapten signal, because other haptenated monoclonal antibodies are ineffective. There is an absolute requirement for a second signal to achieve in vivo suppression; the signal may be substituted by the generation of an allogeneic effect at the time of hapten presentation. We suggest that these methods allow for specific targeting of hapten-suppressive signals that differ considerably from other model systems of tolerance to haptenated immunoglobulins. The results are discussed in relation to a potential role for an Ia+ cell involved in the induction of regulating suppressor pathways.
Normal and malignant human myelocytic and monocytic cells identified by monoclonal antibodies.
Authors: Bernstein I D , Andrews R G , Cohen S F , McMaster B E
Published: December 2022

Two cytotoxic IgM monoclonal antibodies reactive with human cells of myeloid origin are described. Each antibody was tested for reactivity with normal and malignant cells of myeloid origin by using immunofluorescent and cytotoxic assays. Antibody 5F1 defines a determinant expressed by peripheral blood monocytes and platelets. Antibody 1G10 detects a determinant expressed in high concentration on granulocytes and in low concentration on a subset of monocytes. Neither antibody reacts with peripheral blood lymphocytes, erythrocytes, or thymocytes. In bone marrow, 5F1 stains monocytic and nucleated erythrocytic cells, whereas 1G10 stains cells of the granulocytic lineage. Each antibody also reacts with subsets of acute nonlymphocytic leukemia cells. These reagents should be useful in delineating stages of normal and malignant myeloid differentiation.
Anti-f Met-Leu-Phe: similarities in fine specificity with the formyl peptide chemotaxis receptor of the neutrophil.
Authors: Marasco W A , Showell H J , Freer R J , Becker E L
Published: December 2022

We have prepared antisera in both rabbits and rats against f Met-Leu-Phe conjugated to a variety of carrier proteins. Over 40 peptides with widely varying reactivity for the neutrophil formylpeptide receptor have been tested for their ability to bind to rabbit antibody raised against fMLP10-BSA. Structure-activity studies of peptides structurally related to f Met-Leu-Phe demonstrate that the N-formyl group is mandatory for maximum antibody binding activity. Methionine in position 1 and phenylalanine in position 3 are found to confer maximum binding activity. Stereoselectivity of the antibody-combining site also has been demonstrated. Comparison of the ability of the peptides to bind to the antibody receptor with their reactivity for the neutrophil has demonstrated a strong correlation in the rank order of reactivity of the numerous synthetic peptides: for the alpha NH2-acyl group, r = 0.94; for position 1, r = 0.90; for position 2, r = 0.97; and for position 3, r = 0.78. This strong correlation is seen across species lines with both rabbit and rat antibodies. Significant differences, however, in the specificity of the antibody and neutrophil receptors are seen at the carboxyl terminus of phenylalanine, and beyond the phenylalanine ring, r = 0.29. In addition, bacterial chemotactic factor-enriched butanol extracts from Escherichia coli culture filtrates can also bind to anti-f Met-Leu-Phe, affording additional evidence for the similarity in the structure of the bacterial chemotactic factor to the synthetic chemotactic peptides.
Inhibition of human natural killer cell activity by cytophilic immunoglobulin G.
Authors: Sulica A , Gherman M , Galatiuc C , Manciulea M , Herberman R B
Published: December 2022

The natural killer (NK) cell activity of human peripheral blood mononuclear cells (PBL) was found to be increased after incubation at 37 degrees C for 2 hr. The observed increase was shown to be associated with release from inhibition by human serum factors, because incubation in autologous serum interfered with augmentation. The serum-mediated effect appeared attributable to the degree of binding of labile IgG to PBL and could be reduced by selective depletion of IgG from the serum. Human monomeric IgG was found to efficiently inhibit the culture-induced augmentation of NK activity; the inhibitory IgG had properties consistent with those described for cytophilic IgG and was mediated through the Fc region of IgG. The inhibition by monomeric IgG occurred at 0 degrees C as well as at 37 degrees C and this could be induced even after culture-induced augmentation of NK activity. Thus, binding of monomeric IgG to human PBL appears to reversibly inhibit their NK activity. These results provide evidence for a novel mechanism for negative regulation of NK activity.
The production of plasminogen activator by afferent but not efferent lymph cells emigrating from chronic granulomatous lesions in sheep.
Authors: Wasi S , Vadas P , Chin G W , Movat H Z , Hay J B
Published: December 2022

Subcutaneous granulomas were induced in sheep by injecting Freund's adjuvant. At varying times thereafter afferent and efferent lymphatics draining the granulomas were cannulated. Lymph was collected for periods up to several days or weeks from either normal skin or from inflammatory lesions 15 to 120 days after the initiation of the lesions. The fibrinolytic activity of cells and cell culture medium in which cells were grown was assayed by using 125I-fibrin plates. No detectable enzyme activity was found from normal afferent, normal efferent, or stimulated efferent lymph cells. Afferent granuloma cells produced a plasminogen-dependent, DFP inhibitable protease activity that was dependent on the cell concentration and the incubation time. Results of cell separation techniques such as sedimentation velocity, adherence on fibrin plates, and Sephadex G-10 fractionation showed that the large, macrophage-like cell population in afferent lymph was secreting the plasminogen activator. The lymph cells collected from lesions 1 to 2-mo-old were more active than an equivalent number of cells collected from earlier or later lesions. When tuberculin was injected directly into lesions the lymph cells that appeared in the subsequent 1 to 2 days produced more enzyme per cell. The relationship between plasminogen activator and other possible mediators that appear in either the cells or plasma of afferent lymph is discussed.
Streptococcal group A carbohydrate has properties of both a thymus-independent (TI-2) and a thymus-dependent antigen.
Authors: Briles D E , Nahm M , Marion T N , Perlmutter R M , Davie J M
Published: December 2022

Streptococcal group A carbohydrate, which elicits mouse antibody of primarily the IgM and IgG3 isotypes, is relatively nonimmunogenic in nu/nu or xid mice, and thus appears to be a type of TD-2 antigen. The TD-2 antigens described previously have been proteins that elicit IgG antibody primarily of the IgG1 and IgG2 isotypes. Our findings indicate that TD-2 properties may also be a characteristic of at least some carbohydrate antigens that can elicit IgG antibody predominantly of the IgG3 class.
A role for C-reactive protein in the complement-mediated stimulation of human neutrophils by type 27 Streptococcus pneumoniae.
Authors: Edwards K M , Gewurz H , Lint T F , Mold C
Published: December 2022

Although C-reactive protein (CRP) has been shown to be opsonic when bound to erythrocytes, its role in bacterial phagocytosis is unclear. Chemiluminescence (CL), a measure of the metabolic stimulation of neutrophils, was used to investigate the effects of CRP and complement (C) on the interaction between phagocytes and Streptococcus pneumoniae, type 27 (Pn27). CRP binding to Pn27 was demonstrated by using radiolabeled CRP, and Scatchard analysis indicated a saturation binding of about 10(7) CRP molecules/CFU. When Pn27 was pretreated with normal human serum and added to neutrophils, the CL response observed was directly related to the number of bacteria and the amount of serum added. Although bacteria pretreated with CRP alone produced minimal CL, the addition of CRP to serum resulted in a two to 13-fold enhancement of the CL response. CRP enhancement of CL was not observed with heated serum or serum from a patient genetically lacking C2. CRP bound to Pn27 was found to cause consumption of C3 and C4 in normal human serum, indicating activation of the classical C pathway. Because CRP opsonization might provide early protection in the nonimmune host, we tested the ability of CRP to enhance opsonization in serum with markedly decreased immunoglobulin. CRP enhanced the CL response in serum from a hypogammaglobulinemic patient to between 12 and 16 times the serum control. These studies show CRP binds to Pn27 and in the presence of C enhances the opsonization of these organisms. These findings support the concept that CRP plays a protective role in bacterial infection.
Regulation of macrophage populations. V. Evaluation of the control of macrophage Ia expression in vitro.
Authors: Beller D I , Ho K
Published: December 2022

In response to a lymphokine (LK) produced by activated T cells, macrophages can be induced to express Ia in vitro. This appears to be a complex process comprised of a number of discernible events. Peritoneal macrophages elicited by different means, and unstimulated macrophage and monocyte populations, each had a distinct kinetic profile of Ia induction. This response was characterized most noticeably by a latent period before actual Ia expression. The latent period varied from 3 to 7 days, depending on the target population, and was correlated with the state of activation of the macrophage as reflected by 5' nucleotidase activity. In spite of the protracted time course for Ia expression, all macrophage populations could be "triggered" (committed to a subsequent program of Ia expression) by exposure to the LK for as little as 2 hr. To be triggered, however, macrophages first had to go through a period of culture as adherent cells. Both the spontaneous loss and LK-dependent acquisition of Ia correlated with the functional capacity of these macrophages as antigen-presenting cells, indicating that these events are functionally significant.
B cell helper factors. II. Synergy among three helper factors in the response of T cell- and macrophage-depleted B cells.
Authors: Liebson H J , Marrack P , Kappler J
Published: December 2022

The concanavalin A- (Con A) stimulated supernatant of normal spleen cells (normal Con A SN) was shown to contain a set of helper factors sufficient to allow T cell- and macrophage- (M phi) depleted murine splenic B cells to produce a plaque-forming cell response to the antigen sheep red blood cells (SRBC). The activity of normal Con A SN could be reconstituted by a mixture of three helper factor preparations. The first was the interleukin 2- (IL 2) containing Con A SN of the T cell hybridoma, FS6-14.13. The second was a normal Con A SN depleted of IL 2 by extended culture with T cell blasts from which the 30,000 to 50,000 m.w. factors were isolated (interleukin X, IL X). The third was a SN either from the M phi tumor cell line P388D1 or from normal M phi taken from Corynebacterium parvum-immune mice. The combination of all three helper factor preparations was required to equal the activity of normal Con A SN; however, the M phi SN had the least overall effect. The M phi SN and IL 2 had to be added at the initiation of the culture period for a maximal effect, but the IL X preparation was most effective when added 24 hr after the initiation of culture. These results indicate that at least three nonspecific helper factors contribute to the helper activity in normal Con A SN.
Comparison of cell-mediated lympholysis and mixed lymphocyte culture in the immunologic evaluation for renal transplantation.
Authors: Harmon W E , Parkman R , Lavin P T , Grupe W E , Ingelfinger J R , Yunis E J , Levey R H
Published: December 2022

We investigated the relationship between both pre-transplant cell-mediated lympholysis assay (CML) and mixed lymphocyte culture (MLC) and transplant outcome (graft function and survival) in 33 living, related donor renal transplants performed during the past 5 yr. Both assays were excellent predictors of transplant outcome. A positive CML assay was correlated with the occurrence of early acute rejection episodes (p less than 0.005), shortened time to graft dysfunction (serum creatinine greater than 1.5 mg/dl) (p less than 0.001), and poor long-term graft survival (p = 0.07). Similarly, a positive MLC was correlated with acute rejection episodes (p less than 0.005), graft dysfunction (p = 0.001), and poor graft survival (p less than 0.01). To determine the relative prognostic significance of the CML and MLC assays, we compared the correlation of each of them with the occurrence of acute rejection episodes. Under a logistic model of probability, the CML and MLC assays were equally predictive of an early acute rejection episode (p less than 0.01); however, the combination of CML and MLC together improved the accuracy of the prediction of an acute rejection episode by 50%. These results indicate that the CML and MLC assays are independent predictors of transplant outcome and that both tests should be an integral part of the immunologic evaluation of prospective living, related donors for renal transplantation.
Trypanosoma rhodesiense blood forms express all antigen specificities relevant to protection against metacyclic (insect form) challenge.
Authors: Esser K M , Schoenbechler M J , Gingrich J B
Published: December 2022

Monoclonal antibodies were used to demonstrate the expression of four distinct metacyclic (infective insect form) trypanosome antigens on blood forms of T. rhodesiense. Metacyclic antigens were consistently expressed on the blood forms on days 4 and 5 of the first parasitemia after metacyclic infection of C57BL/6 mice. In different mice examined, the percent of blood forms expressing metacyclic antigens ranged from 46 to 85%. Immunization with irradiated day-5 blood form trypanosomes was protective against metacyclic challenge, indicating that all antigen specificities relevant to protective immunization against metacyclic challenge are expressed on blood form trypanosomes. Blood forms, in contrast to metacyclic forms, can be isolated in quantities sufficient for purification of antigens and genetic cloning.