bluuebunny/crossref_metadata_2025 huggingface dataset:
Radioimmunoassay of IgG and IgM Rheumatoid Factors Reacting with Human IgG
Authors: Carson Dennis A. , Lawrance Simon , Catalano Michael A. , Vaughan John H. , Abraham George
Published: December 2022

Although IgG rheumatoid factor may play a central role in the pathogenesis of rheumatoid arthritis, previously there have been no precise methods for its specific measurement in serum and synovial fluid. This paper describes a solid phase radioimmunoassay for the independent quantification of IgM and IgG rheumatoid factor reacting with the Fc fragment of human IgG. As measured by this assay, serum IgG rheumatoid factor levels differed significantly between patients with seropositive and seronegative rheumatoid arthritis and normal control subjects. In addition, several sera and joint fluids from patients with seropositive rheumatoid arthritis, even without vasculitis, were shown by gel chromatography to have acid-dissociable complexes of IgG rheumatoid factor suggestive of IgG-IgG dimer or trimer formation.
A New Method of Applying the Sips Equation
Authors: Nahm Moon H. , Herzenberg Leonard A. , Little Katharine , Little J. Russell
Published: December 2022

The Sips equation is frequently used in immunochemistry to describe the relationship between antibody-binding site concentration (no[Ab]), antigen concentration, intrinsic affinity constant (K), and the heterogeneity index (a) of the affinity constant. Usually no[Ab] is determined before calculating the remaining parameters (K and a). A new method is proposed which does not require knowledge of no[Ab] nor an extensive calculation to determine K and a. The method can also be used to determine the antibody-binding site concentration without purified antibody or ligand saturation of the binding sites. This method can be applied to any antibody which binds a monovalent ligand and which can be obtained at a concentration greater than 1/K. Since the Sips equation can be applied to any ordinary chemical reaction by setting a = 1, the proposed method can be used generally to determine the affinity constant and the initial concentration of one of the reactants.
Failure of B Lymphocytes in Human Blood to Regenerate Surface Immunoglobulin after its Removal by Antibody
Authors: Ault Kenneth A. , Unanue Emil R.
Published: December 2022

In culture, human blood B cells regenerated surface IgM and IgD after their removal by a brief treatment with pronase. In contrast, surface Ig was poorly reexpressed after interaction with specific antibody. Both classes of surface Ig were suppressed after treatment with antibody specific for only one. B lymphocytes from spleen and tonsils regenerated surface Ig after treatment with either pronase or anti-Ig. We suggest that the particular sensitivity of circulating B cells to anti-Ig-surface Ig interaction may be reflection of their state of maturation.
Studies on the Nature of the Relationship Between Ia Antigens and Fc Receptors on Murine B Lymphocytes
Authors: Dickler Howard B. , Kubicek Mary T. , Arbeit Robert D. , Sharrow Susan O.
Published: December 2022

Possible mechanisms for the specific inhibition by anti-Ia antibody of the binding of Ig complexes to B lymphocyte Fc receptors were evaluated. Capping of B cell Fc receptors did not lead to redistribution of antigens determined by genes in the I region or the I-A or I-C, I-E subregions as analyzed by indirect fluorescence and visual microscopy. In addition, the amounts of these antigens which could be quantitatively detected with indirect fluorescence and flow microfluorometry were unaltered by capping of Fc receptors. Thus, Ia antigens and B lymphocyte Fc receptors do not appear to be identical.

Quantitation of Ia antigens after binding of Ig complexes to B cell Fc receptors under noncapping conditions revealed partial (6 to 10%) inhibition of detection of antigens determined by genes in the whole I region but no inhibition of I-A or I-C, I-E subregion antigens. Thus, the majority of Ia antigens do not, in the native state, appear to lie in close physical proximity to B cell Fc receptors.

In view of the fact that the Fc portion of anti-Ia antibodies is not required to produce inhibition of binding to B cell Fc receptors, these observations suggest that this inhibition is due to a ligand-induced alteration of Ia antigens which leads to an interaction with the Fc receptors of B lymphocytes. Such Ia antigen-Fc receptor interactions may play a role in B cell activation.
Murine Plasma Cells Secreting More Than One Class of Immunoglobulin Heavy Chain
Authors: Morse Herbert C. , Goode Julius H. , Rudikoff Stuart
Published: December 2022

The amino terminal sequences of the κ light chains from SAMM 368 IgG2b and IgA have been determined. The two chains belong to different κ subgroups as indicated by 10 amino acid differences among the first 23 residues. An additional three residue differences were demonstrated in the sequence including the first complementarity region. These results indicate that single cells of SAMM 368 produce two unique κ-chains.
Identification and Partial Purification of Two Synergistically Acting Helper Mediators in Human Mixed Leukocyte Culture Supernatants
Authors: Farrar John J. , Koopman William J. , Fuller-Bonar Janet
Published: December 2022

The present study was undertaken to fractionate and identify the stimulatory factors within the mixed leukocyte culture (MLC) supernatant which induce a 150- to 1000-fold increase in the in vitro plaque-forming cell (PFC) response of T cell-deficient normal mouse adherent spleen cells. G-75 Sephadex gel filtration of the allogeneic supernatant revealed three distinct peaks of helper activity which were designated helper peaks (HP) 1, 2, and 3. The m.w. estimates for the three components were: HP-1, 10 to 15,000 daltons; HP-2, 40 ≥ 77,000 daltons; and HP-3, 20 to 25,000 daltons. HP-1 and HP-2 were further investigated and found to contain minimal helper activity at their respective optimal concentrations when compared to the activity of the unfractionated supernatant. The two components did, however, exhibit the remarkable capacity to effect synergistically an almost complete restoration of the PFC response. Expression of the helper factor synergism was dependent on the absolute concentration of HP-1 in the cultures but relatively independent of the amount of HP-2. Furthermore, the capacity of HP-1 to synergize with HP-2 was also dependent on the introduction of HP-1 to the cultures during the first 20 hr of the incubation period, suggesting that this component was crucial to the initiation of the PFC response. The results suggest that HP-1 and HP-2 have distinct sites-of-action in the B cell activation pathway and that full expression of the PFC response is dependent on the lymphostimulatory events mediated by these two moieties.
No Direct Association between Ia Antigens and Fc Receptors on the B Cell Membrane
Authors: Wofsy Leon , McDevitt Hugh O. , Henry Claudia
Published: December 2022

The capping of Ia antigens does not induce redistribution of Fc receptors (FcR) on B lymphocytes. This rules out the possibility of a unidirectional association between Ia and FcR such as has been reported to link Ig and FcR. Iacapping was achieved with hapten-sandwich antibodies devoid of Fc regions: hapten-conjugated Fab anti-Ia followed by (Fab′)2 anti-hapten antibody. Three different immune complex systems were used to label FcR. With fluorescent double labeling, Ia and FcR were readily distinguished. The independent labeling and surface mobility of Ia and FcR are considered in connection with reports of the inhibition of FcR by anti-Ia antibodies.
Mediation of Macrophage Cytolytic and Phagocytic Activities by Antibodies of Different Classes and Class-Specific Fc-Receptors
Authors: Walker William S.
Published: December 2022

The classes of antibodies that mediate the phagocytosis and cytolysis of 51Cr-labeled chicken erythrocytes by IC-21 macrophages, an established line of mouse peritoneal macrophages, were identified. The phagocytic activity of IC-21 macrophages, as determined by a functional inhibition assay with mouse myeloma proteins, depended mainly on IgM and IgG2a antibodies and to a lesser extent on IgG2b antibodies. Extracellular cytolysis of target cells was mediated solely by IgG2b antibodies. These results correlate with the previously documented specificities of discrete Fc-receptors for IgG2a and IgG2b immunoglobulins on IC-21 cells. Thus, phagocytosis and cytolysis appear to be mediated by antibodies of different classes operating through separate and distinct sites on the surface of IC-21 macrophages.
Expression of Thymocyte Surface Alloantigens in the Fetal Mouse Thymus in vivo and in Organ Culture
Authors: Kamarck Michael E. , Gottlieb Paul D.
Published: December 2022

Cell proliferation and surface alloantigen expression were monitored during development of the fetal mouse thymus in vivo from day 13 of gestation until birth, and in organ cultures established at day 13 of gestation. Expression of Thy-1, Ly-1, Ly-2, Ly-3, TL, GIX, and H-2b determined alloantigens was assessed with specific antisera in one- and two-stage complement-dependent microcytotoxicity assays. A series of C57BL/6-congenic strains was employed to control for effects of the genetic background. Results indicate that at day 13 of gestation alloantigen expression is too low for detection by the cytotoxic assay. From day 14 until birth, exponential cell proliferation is accompanied by gradual increase in alloantigen expression, and by day 19, Ly-1, Ly-2, Ly-3, Thy-1, and GIX are expressed at adult levels, whereas TL expression is higher and H-2b expression is lower than is seen in the adult thymus. In fetal thymus organ cultures established at day 13 of gestation, cell proliferation was not so extensive as was seen in vivo, and by 6 to 8 days in culture, Thy-1 was expressed on essentially all the cells. The other alloantigens were detectable on only 30 to 45% of the cells. Both in vivo and in vitro, the Ly-1, Ly-2, and Ly-3 alloantigens appeared simultaneously on the same population of thymocytes. Results are compared with the reported kinetics of alloantigen expression induced in prothymocytes upon exposure to thymopoietin.
Abrogation of Resistance to Foreign Bone Marrow Grafts by Carrageenans
Authors: Cudkowicz Gustavo , Yung Yee Pang
Published: December 2022

Natural resistance of mice to transplants of foreign bone marrow or leukemia cells is mediated by radioresistant non-T effectors which may interact with accessory macrophage-like cells sensitive to the toxicity of silica particles. The role of the accessory cells was reinvestigated by means of the soluble antimacrophage agent Seakem-9 carrageenan, and for comparison with silica particles. The agents abrogated or weakened resistance to parental, allogeneic, and xenogeneic rat marrow grafts when a single relatively small dose (2 mg/mouse or less) was injected intravenously into irradiated mice, 5 to 24 hr after transplantation. This effect was dose dependent, not influenced by the sex of recipients and donors and, unlike the effect of silica particles, not prevented by the previous injection into the mice of the lysosomal stabilizer (i.e., macrophage protector) poly-2-vinylpyridine N-oxide. This discrepancy raised the possibility that carrageenan weakened resistance by impairing the function of cells other than macrophages, whereas silica particles did so by way of selective macrophage depletion. However, the combined effect of suboptimal doses of carrageenan and silica particles was additive, a result which favors the view that carrageenan functioned as an anti-macrophage agent in vivo. These experiments reiterate the importance of macrophage-like cells interacting with radioresistant non-T cells (presumably null lymphocytes) in the development of natural cell-mediated responses such as resistance to hemopoietic grafts and generation of killer cells for certain lymphomas.
Target Cell-Substratum Interaction
Authors: David Gary S. , Wiglesworth Charlotte M.
Published: December 2022

When trypsinized cells were treated with alloantibody and complement they initially adhered to their substratum, then detached. Specific cytolysis did not occur. In addition to demonstrating an immunologically mediated reaction, this phenomenon has permitted the development of a new, simple, rapid assay for alloantibody that does not require a cytolytic reaction.
Immunologic Properties of Protein-Lipopolysaccharide Complexes
Authors: Scibienski R. J. , Gershwin M. E.
Published: December 2022

The in vivo antibody response to the lysozyme component of a lysozyme-lipopolysaccharide complex has been investigated in normal, thymectomized and nude mice. The splenic PFC response elicited by the complex in CBA mice is 10- to 20-fold higher than the response elicited by lysozyme admixed with LPS. Both lysozyme-LPS complexes and lysozyme + LPS mixtures prime mice for a subsequent secondary anti-lysozyme response. In contrast, thymectomized mice responded poorly to lysozyme-LPS complexes unless reconstituted with splenic T cells. However, nude mice responded as well as Nu/+ controls to the complex. The PFC response of normal and of nude mice was severely depressed by treatment with anti-lymphocyte serum. These findings suggest that T lymphocytes contribute significantly to the enhanced immune responsiveness associated with LPS administration.
Allotype Suppression in Rabbits: The Requirement for CH3 Domain of Anti-Allotype Antibody
Authors: Connell George E. , Dubiski Stanislaw
Published: December 2022

Facb fragments of rabbit anti-allotype antibody were prepared by plasmin digestion and isolated by gel chromatography. The antibody preparation was used in an attempt to induce allotype suppression in newborn rabbits. The Facb fragments were found to be ineffective in inducing the allotype suppression. Administration of Facb fragments caused a “burst” of immunoglobulin synthesis almost immediately after the administration of the antibody. It was concluded that the CH3 domain, which is responsible for the cytophilic activity of the antibody, is essential in induction of allotype suppression.
The Amino Acid Sequence of a Human Immunoglobulin G3m(g) pFc′ Fragment
Authors: Michaelsen Terje E. , Frangione Blas , Franklin Edward C.
Published: December 2022

Amino acid sequence analysis of the pFc′ fragment obtained by pepsin digestion of an IgG3; G3m(g) human myeloma protein HER shows it to consist of 112 residues. It starts at position 334 (γ1 numbering), contains eight residues of the Cγ2 region, and the whole Cγ3 domain. Comparison with the sequence of γ1 shows five differences including an extra Met at 397. Each is accountable by a single base substitution. The sequence is identical to that of a G3m(b0) molecule except for the previously noted allotype related Tyr/Phe exchange at position 436. The high degree of homology (95%) among γ-chain subclasses suggests a recent diversification.
Activation of Human B Lymphocytes
Authors: Fauci Anthony S. , Pratt Karen R. , Whalen Gail
Published: December 2022

In vitro hydrocortisone in physiologic and pharmacologically attainable concentrations caused a marked enhancement of the PWM-induced PFC response of normal human peripheral blood B lymphocytes. This effect was seen only when hydrocortisone was added within the first 24 hr of culture and only when hydrocortisone and PWM were present together in cultures. Only suprapharmacologic concentrations of hydrocortisone (10-3 M) were capable of suppressing early B cell activation. Late stages of antibody production and secretion were resistant to suppression by even these extraordinarily high concentrations. Hydrocortisone did not replace the T cell requirement of PWM-induced PFC responses. A single dose of in vivo hydrocortisone (400 mg) to normal adult volunteers did not produce this enhancing effect when PFC responses were measured in vitro in the absence of hydrocortisone.

The data strongly suggest that the enhancing effect of hydrocortisone was due not to elimination of naturally occurring suppressor cells, but to a modulation of the triggering signal either directly on the B cell itself or via the balance of positive and negative T cell regulation of B cell activation.
Release of Slow Reacting Substance (SRS) from Rat Basophilic Leukemia (RBL-1) Cells
Authors: Jakschik Barbara A. , Kulczycki Anthony , MacDonald Hanna H. , Parker Charles W.
Published: December 2022

When rat basophilic leukemia (RBL-1) cells were exposed to the ionophore A23187, a substance was released that produced a prolonged contraction of guinea pig ileum resembling that seen with slow reacting substances (SRSs) from various sources. The response was temperature, dose, and the time dependent with no activity being demonstrated in unstimulated cells. Several lines of evidence indicated that the RBL-1 product was markedly similar or identical to SRSs obtained from non-neoplastic tissues: 1) appropriate behavior in seven different chromatographic systems, 2) an appropriate profile of activity on various smooth muscle preparations, 3) an ability of low concentrations of the selective SRS inhibitor FPL 55712 to block the guinea pig ileal response, 4) failure of chymotrypsin to destroy activity, 5) loss of the activity after incubation with arylsulfatase, and 6) an ability to release activity from cells preincubated with indomethacin. Since RBL-1 cells can be grown in considerable quantity and under optimal conditions an average of 1500 SRS units/107 cells can be obtained, these cells should be useful as a biosynthetic source in further attempts to purify and characterize the SRS molecule.
Characterization of Effector Lymphocytes Associated with Immunity to Murine Sarcoma Virus (MSV)-Induced Tumors
Authors: Plata Fernando , Jongeneel C. Victor
Published: December 2022

Cytolytic T lymphocytes (CTL) and specific CTL precursor cells can be generated during the immune response to syngeneic tumors induced by murine sarcoma virus (MSV) in the mouse. MSV-immune spleen cells yield high numbers of specific CTL after incubation in vitro with irradiated tumor cells in syngeneic secondary mixed leukocyte-tumor cell cultures (sec-MLTC). Peak cytolytic activity generated in sec-MLTC is detectable on day 7 after culture initiation and decreases slowly thereafter. This report presents data showing that highly active CTL could be regenerated upon tertiary stimulation of long-term sec-MLTC with irradiated tumor cells bearing MSV-associated antigens. CTL activity recovered from tertiary MLTC could be detected in a short-term (3 hr) 51Cr release assay, and increased levels of cytolysis were already evident 24 hr after culture re-initiation. It was also shown that cells recovered from MLTC 12 days after tertiary restimulation could be further stimulated by specific tumor antigen in quaternary MLTC to yield increased CTL numbers. These results thus indicated that T lymphocytes could be repeatedly stimulated by specific tumor antigen in syngeneic MLTC to yield increasing numbers of cytolytic cells. Furthermore, the tumor antigen used for the initial stimulation of MSV-immune spleen cells in sec-MLTC appeared to have induced a specific selection of CTL precursor cells, since only syngeneic tumor cells bearing MSV-associated antigens were capable of inducing high levels of CTL regeneration in tertiary MLTC.
Serum Amyloid A (SAA) Protein — Interaction with Itself and Serum Albumin
Authors: Rosenthal C. Julian , Franklin Edward C.
Published: December 2022

Serum amyloid A (SAA) protein is a 12,000 dalton protein that exists in serum under physiologic conditions as an 85,000 dalton complex and under certain conditions, as a 170,000 dalton component. To study the reason for this finding, the behavior of 125I-SAA was studied in the presence of cold SAA and several serum proteins. SAA caused a shift of some of the radioactivity to the region of albumin. Addition of normal human serum or albumin caused a shift of a significant fraction of the radioactivity to a peak eluting slightly ahead of albumin (80,000 daltons). This interaction could be blocked by the addition of cold SAA. No shift was noted when IgG or Bence Jones proteins were added. Thus, it appears that low molecular SAA protein has a tendency to aggregate with itself and to bind to albumin but not to human IgG or Bence Jones proteins.
The Nature of Immune Complexes in Human Cancer Sera
Authors: Theofilopoulos Argyrios N. , Andrews Brian S. , Urist Marshall M. , Morton Donald L. , Dixon Frank J.
Published: December 2022

Sera from 517 patients with various types of malignancies were assayed for immune complexes (ICs) by the Raji cell radioimmune assay. The incidence of immune complexes in these patients ranged from 16 to 52% as compared to 19% in normal controls. Increases in tumor mass and metastatic disease were associated with high levels of circulating ICs. Immunization of melanoma patients with BCG and tumor-cell vaccine produced an increase in levels of ICs. Cancer sera contained complexes of intermediate size. Tumor antigens and IgG, presumably in the form of complexes, were identified by immunofluorescence and radiolabeled antibody techniques on the surface of Raji cells incubated in ICs-containing cancer sera.
Studies of the Relationship between Adenosine Deaminase and Immune Function
Authors: Burridge Philip W. , Paetkau Verner , Henderson J. Frank
Published: December 2022

The relationship between adenosine deaminase deficiency and immunologic responsiveness was studied in mice treated in vivo with deoxycoformycin to produce very low levels of adenosine deaminase activity in tissues. Effects of such treatment on thymocyte response to concanavalin A in vitro and on mixed cultures of splenic cells were determined. Under the conditions used, inhibition of adenosine deaminase by deoxycoformycin had no effect on the viability or responsiveness of either thymocytes or splenic cells.
Sera and the in Vitro Induction of Immune Responses
Authors: Shiigi Stanley M. , Capwell Robin R. , Grabstein Kenneth H. , Mishell Robert I.
Published: December 2022

We have extended our studies on the role of bacterial contamination in the generation of fetal calf sera which support primary in vitro humoral responses by cultured mouse spleen cells. Gram-negative, gliding bacteria were isolated from a strongly supportive sample of fetal calf sera. Medium conditioned by the growth of these microorganisms had strong adjuvant effects in cultures of mouse spleen cells supplemented with a non supportive, deficient sera. The adjuvant and mitogenic activities of the bacterial conditioned medium were then compared to those of bacterial lipopolysaccharide from Salmonella typhosa 0901 in cultures of LPS responder and LPS nonresponder spleen cells. From the results of these comparative studies, we conclude that the active factor(s) obtained from the gliding bacteria is an adjuvant with properties very distinct from those of highly purified enteric bacterial LPS.
Immunosuppression of Experimental Autoimmune Myasthenia Gravis by Azathioprine
Authors: Tarrab-Hazdai Rebeca , Abramsky Oded , Fuchs Sara
Published: December 2022

Azathioprine was shown to be effective in suppressing the onset of experimental autoimmune myasthenia gravis (EAMG) in rabbits injected with acetylcholine receptor (AChR) from Torpedo californica. The correlation between clinical effects and several immunologic parameters resulting from the immunosuppressive treatment was studied.

Administration of azathioprine for 5 months prevented the appearance of EAMG for at least 12 months, even after discontinuation of the treatment, in rabbits injected once with AChR. The suppressive effect of azathioprine was followed by a decreased cellular reactivity such as lymphocyte transformation and binding of AChR to macrophages, as well as a decreased humoral reactivity such as levels of total circulating antibodies and of cytophilic antibodies. Whereas the cellular and humoral sensitivities toward the immunizing Torpedo receptor were decreased, the reactivity against self AChR was essentially abolished. The strong effect on the autoimmune reactivity may assign some specificity to the treatment with azathioprine in affecting selectively certain cell populations. It is possible that immune responses directed against certain antigenic determinants that may be actively involved in the pathogenesis of EAMG are selectively more affected by azathioprine. The immunologic findings should prove useful in assessing and evaluating azathioprine treatment of the human disease.
Suppression of B Cell MIF Production by T Cells and Soluble T Cell-Derived Factors
Authors: Cohen Stanley , Yoshida Takeshi
Published: December 2022

Purified populations of guinea pig B cells from nonimmunized animals may be stimulated by PPD or LPS to produce MIF. Unfractionated lymphocyte suspensions from these animals do not produce MIF under these conditions. Reconstitution of B cells with T cells abolishes their ability to generate detectable MIF. A soluble factor obtained from stimulated T cell cultures (MIFIF) is also capable of suppressing this B cell activity. Thus suppressor T cells can interfere with lymphokine production by B cells and this effect is mediated at least in part by a soluble factor. This previously undescribed capacity of T cells may provide an explanation for the fact that B cells do not appear to play a role in reactions of cell-mediated immunity in vivo.
Expression and Function of I Region Determinants on Immunocompetent Cells
Authors: Henry Claudia , Chan Eva L.
Published: December 2022

We have examined the cytotoxic activity of anti-Iak serum and complement on various immune functions of BALB/c (H-2d) cells. Since the cytotoxic action of this antiserum on H-2d cells defines specificity Ia.7, an I-C region product, we have looked at the selective expression of this antigen. We have mainly used the in vitro anti-Lac2 response to study the cells involved in the induction and regulation of antibody. The data presented here show that Ia.7 is present on both IgM and IgG precursor B cells and in lesser amounts on plaque-forming cells. The antiserum also recognizes with less efficiency a product on specific T suppressor cells, which is possibly coded for by the adjacent I-J subregion. Both fluorescence and functional tests indicate the absence of Ia.7 on macrophages. It is also lacking on T helper cells. When we tested the antiserum on the in vitro cytotoxic responses to alloantigens, we found that neither T effector cells nor their precursors were affected.
Regulation of Cell-Mediated Cytotoxicity
Authors: Babu U. M. , Sabbadini Edris
Published: December 2022

Lethally irradiated F1 hybrid mice were given an i.v. injection of parental strain spleen cells. Six days later, their spleen cells were used as the effector cells to measure the in vitro cell-mediated cytotoxicity (CMC) of the parental cells. The treatment of the donors with hydrocortisone resulted in a marked decrease of the capacity of their spleen cells to produce a CMC reaction, whereas the treatment with antithymocyte serum (ATS) resulted in an almost complete loss of such activity. The mixing of spleen cells from hydrocortisone-treated parental donors with the spleen cells from ATS-treated parental donors before injection resulted in a synergistic amplification of the cytotoxic response. The anti-Thy-1 serum treatment of either spleen cell population abolished the synergism completely. These results indicate that cortico-resistant T cells act as precursors of cytotoxic lymphocytes and that ATS-resistant T cells produce an amplification of their reaction.
The Antibody Response to the T1699 Murine Adenocarcinoma: Antibody Class and Subclass Heterogeneity Detected in Serum and in Situ
Authors: Haskill J. S. , Radov L. A. , Fett J. W. , Parthenais E.
Published: December 2022

We have used indirect immunofluorescence to study antibody responses directed against membrane antigens expressed on in vitro and in vivo T1699 mammary adenocarcinoma cells. IgG1, IgG2a, IgG2b, IgG3, IgA, and IgM antibodies were present in the serum of DBA/2 mice bearing T1699 tumors; IgG2a and IgG2b antibodies were readily detected on the cells in situ. Lesser amounts of the other classes and subclasses could be detected by indirect immunofluorescence measurements on in vivo tumor cells and with low pH eluates of in vivo cells tested on the in vitro line of T1699. The antigenic determinants on in situ tumor cells are not saturated with antibody as these cells demonstrated enhanced fluorescence of all immunoglobulin classes and subclasses when treated with autologous serum. Experiments with thymus-depleted mice indicated that immunoglobulin production was strongly dependent on thymus-derived cells for all immunoglobulin classes and subclasses except IgG2b. Our studies suggest that IgG2a may be active in the macrophage-mediated cytotoxic reaction and IgG2b in the immediate hypersensitivity reaction to T1699 cells. These results provide further evidence for an active role of tumor-specific antibody in the host defense to the T1699 adenocarcinoma in situ.
Studies on the Cytotoxic Activity of Human Lymphocytes
Authors: Ziegler H. Kirk , Henney Christopher S.
Published: December 2022

The inhibition of human K cell-mediated cytolysis by a variety of immunoglobulin preparations was studied. It was found that inhibition was not a simple function of IgG concentration but was dependent on the mode of immunoglobulin presentation. The relative inhibitory capacity of IgG preparations on a weight basis was as follows: cell associated Ig ≥ immobilized immune complexes τ; insoluble immune complexes τ; soluble immune complexes τ; heat-aggregated Ig ≫ monomeric Ig. These results imply that the inhibitory capacity of immunoglobulin is determined by ligand (Fc) multivalency.

It was found that although interactions between immunoglobulin and Fc receptors occur at low temperatures, these interactions lead neither to lysis nor to K cell inactivation. A temperature-sensitive post-binding event was required both for lysis to occur and for K cells to be inactivated.

These findings lead us to propose that an IgG-induced redistribution (“capping”) of Fc receptors on the K cell surface may be required for cytolysis and for effector cell inactivation.
Differentiation of Lymphoid Cells: The Preferential Binding of the Lipid a Moiety of Lipopolysaccharide to B Lymphocyte Populations
Authors: Zimmerman D. H. , Gregory S. , Kern M.
Published: December 2022

Lipid A, prepared from lipopolysaccharide, was labeled with 125I. Such iodinated lipid A possesses the full mitogenic activity of untreated lipid A. Comparison of the 125I-lipid A-binding activity of splenocytes and thymocytes from the same rabbit revealed that the extent of labeling of splenocytes was 10 to 20 times greater than that observed with an equivalent number of thymocytes. A similar preferential binding was detected in comparing cells in mouse and rat. Spleen populations depleted of adherent cells were essentially unaltered with regard to binding when compared to the original population. In addition, spleen cell populations enriched for thymus-derived cells (T cells) exhibited a marked loss of specific binding activity. On the other hand, spleen cell populations enriched for bone marrow-derived cells (B cells) exhibited the expected binding. The difference in binding behavior of B and T cell-enriched populations was confirmed by using three independent techniques to separate B and T cells. These findings are consistent with the mitogenic specificity of lipid A toward B cells rather than T cells and suggest that the observed cellular specificity resides in an early event in mitogenesis, i.e., binding of the mitogen.
Antibody-Dependent Cellular Cytotoxicity Effector Cells Lack Ia Antigens
Authors: Nelson David L. , Sachs David H. , Dickler Howard B.
Published: December 2022

Surface immunoglobulin (sIg)-positive and sIg-negative subpopulations of macrophage-depleted murine splenic lymphocytes were obtained by Sephadex anti-Fab immunoabsorbent fractionation. These lymphocyte subpopulations were analyzed for the presence of Thy 1 and Ia alloantigens and also for Fc receptors by fluorescence microscopy. Concurrently, these lymphocyte subpopulations were studied for effector cell activity in antibody-dependent cellular cytotoxicity (ADCC). Effector cells mediating ADCC were contained in the sIg-negative lymphocyte subpopulation and sIg-positive lymphocytes did not mediate cytotoxicity. The majority of sIg-positive lymphocytes were found to bear Ia antigens and Fc receptors, and these cell surface structures were associated in that treatment of these cells with anti-Ia sera inhibited binding of complexed immunoglobulin to Fc receptors. In contrast, most sIg-negative, Thy 1-negative lymphocytes lacked Ia antigens, and the Fc receptors detected on such cells were not blocked by anti-Ia sera. In addition, a small subpopulation of sIg-negative, Ia antigen-positive, Fc receptor-positive lymphocytes was found. Elimination of this subpopulation of Ia antigen-positive cells from sIg-negative lymphocytes, by treatment with anti-Ia serum and complement, did not diminish ADCC effector cell activity in the resultant cell population when compared with untreated sIg-negative lymphocytes. Thus, in murine spleen, nonphagocytic mononuclear cells that lack both sIg and Ia antigens were shown to mediate ADCC.
Studies on the Induction and Expression of T Cell Mediated Immunity
Authors: Grimm Elizabeth A. , Bonavida Benjamin
Published: December 2022

The lytic efficiency of isolated alloimmune cytotoxic lymphocytes (CTL) has been examined, following the development of a method to highly enrich for cytotoxic T lymphocytes (CTL) by specific binding to allogeneic target cells. Murine effector-target cell conjugates, prepared by mixing populations of immune lymphocytes (generated in vitro and in vivo) with allogeneic tumor target cells, were enriched by rate sedimentation through a discontinuous fetal calf serum (FCS) gradient. The bottom layer contained 80 to 90% conjugated lymphocytes, or an enrichment of 3- to 6-fold and a recovery of approximately 50%. Isolation by a microdilution technique, followed by single-cell, cell-mediated cytotoxicity (CMC) assay proved that an average of 70% of the conjugating lymphocytes from both primary and secondary responses lysed their attached target cell. The absolute frequency of CTL in any immune T cell population was determined by correcting the percentage of conjugates by the factor of those conjugating lymphocytes observed to kill in the single-cell CMC assay.

Using these techniques of CTL enrichment and single-cell assay, results have been obtained that provide evidence for heterogeneity of CTL lytic potential. The intrinsic lytic efficiency of individual CTL was determined by quantitation of the time intervals required for target lysis by 1373 conjugated lymphocytes. Up to 5 hr for primary and 4 hr for secondary CTL was necessary to achieve maximum single-target lysis at 37°C. In addition, the average 1° CTL displayed a slower rate of killing than the average 2° CTL. It was found that the time required for lysis by 50% of the 1° lymphocytes was 2.5 hr and for 2° lymphocytes was 1.2 hr, demonstrating that cytotoxic lymphocytes are heterogeneous in their lytic potential. Heterogeneity of lytic efficiency by CTL was also shown by experiments demonstrating a poor correlation between the frequency of conjugating lymphocytes and the cytotoxicity measured by 51Cr release.
Binding Site of Human IgG Subclasses and Their Domains for Fc Receptors of Activated Murine T Cells
Authors: Klein Michel , Neauport-Sautes Catherine , Ellerson James R. , Fridman Wolf H.
Published: December 2022

A subpopulation of activated murine T cells (25%) were found to bear Fc receptors for mouse, rabbit, and human IgG. Studies, by rosette inhibition and indirect immunofluorescence, of their specificity for human IgG subclasses have shown that these receptors bound nonaggregated IgG1, IgG2, and IgG3 in a comparable fashion, but did not bind IgG4. The binding site has been localized exclusively to the Fc region and the binding capacity of this fragment was not affected by mild reduction. Binding of the Fc fragment of IgG4 could not be demonstrated. Using isolated Cγ2 and Cγ3 (pFc′) domains from IgG1 and a Cγ3-derived fragment (Fc′), a major binding site was localized to the Cγ3 domain between residues Gln342 and His433. A 10-fold molar excess of Cγ3 dimer over native Fc was, however, required to show comparable activity. The monomeric Cγ2 domain was 10-fold less active than the Cγ3 fragment. Human urine β2-microglobulin was not cytophilic. These data are discussed and it is suggested that the Cγ2 and Cγ3 domains may contribute to the formation of a cooperative binding site through quaternary interdomain interactions.

By redistribution experiments, it was demonstrated that the three human IgG subclasses shown to be cytophilic share common or linked receptors, which were not associated with the H-2 alloantigens.
Thymosin-Induced Human Serum Factor Increasing Cyclic AMP
Authors: Astaldi Alberto , Astaldi Giulia C. B. , Wijermans Pierre , Groenewoud Marjorie , Schellekens Peter Th.A. , Eijsvoogel Vincent P.
Published: December 2022

Thymosin has virtually no in vitro effect on cyclic AMP levels in thymocytes and seems not to react with either the β-adrenergic receptor or with the putative human serum thymic factor (SF) receptor. However, when thymosin is injected into patients lacking SF activity, it induces the appearance of a serum factor which increases cellular cyclic AMP levels in thymocytes in vitro. This factor appears to act on a membrane site distinct from the β-adrenergic receptors.
Altered Humoral Immune Response to Sheep Red Blood Cells by Sheep Erythrocyte-Soluble Hemolysate
Authors: Davis-Miller Merdis , Bratcher Ray L.
Published: December 2022

Adult C3H/He mice were rendered unresponsive to a primary injection of sheep red blood cells (SRBC) by pretreatment with sheep hemolysate supernatant (SHS) or subfractions of SHS isolated by column chromatography. The following effects of SHS on the immune response were observed: SHS did not kill antigen-reactive cells, it did not prevent the release of antibody by cells actively synthesizing and secreting antibody, and SHS-induced tolerance was not inhibited or abrogated by methods which terminate or abolish tolerance. In addition, cell-mediated responses were not affected in animals whose humoral responses were suppressed; however, the secondary plaque-forming cell (PFC) response was enhanced by SHS treatment. SDS gel electrophoresis revealed SHS to contain several proteins ranging from 12,000 to approximately 500,000 daltons.
Experimental Allergic Encephalomyelitis: Enhancement of Cell-Mediated Transfer by Concanavalin A
Authors: Panitch Hillel S. , McFarlin Dale E.
Published: December 2022

Adoptive transfer of experimental allergic encephalomyelitis (EAE) with splenic lymphocytes from Lewis rats sensitized to myelin basic protein (BP) was potentiated by incubation of the cells in vitro with concanavalin A (Con A). Spleen cells of donors which had recovered from EAE also transferred the disease readily after activation by this procedure. In contrast, the transfer of activity of lymph node cells was not altered. We conclude that during the course of EAE a population of T cells with immunologic memory for BP is generated and persists in the spleen. Incubation with Con A activates these cells and results in marked enhancement of their ability to transfer the disease.
Fucose-Binding Lotus tetragonolobus Lectin Binds to Human Polymorphonuclear Leukocytes and Induces a Chemotactic Response
Authors: VanEpps Dennis E. , Tung Kenneth S. K.
Published: December 2022

Fucose-binding L. tetragonolobus lectin binds to the surface of human polymorphonuclear leukocytes (PMN) and induces a chemotactic response. Both surface binding and chemotaxis are inhibited by free fucose but not by fructose, mannose, or galactose. The lectin-binding sites on PMN are unrelated to the A, B, or O blood group antigen. Utilization of this lectin should be a useful tool in isolating PMN membrane components and in analyzing the mechanism of neutrophil chemotaxis.
Immunologic Classification of Neisseria Gonorrhoeae with Micro-Immunofluorescence
Authors: Wang San-Pin , Holmes King K. , Knapp Joan S. , Ott Susanne , Kyzer David D.
Published: December 2022

A reproducible immunologic classification of Neisseria gonorrhoeae strains has been achieved by the micro-immunofluorescence (Micro-IF)3 method by using formalinized whole organisms as test antigens and mouse antisera prepared by i.v. immunization with the whole organisms as antibody. Immunologic differences among Neisseria species were also distinct in this test system. Immunologic differences among gonococcal strains were not influenced by gonococcal colony type. Classification of gonococci was facilitated by use of antisera absorbed with an antigenically unique gonococcus strain.

Of 180 gonococcal strains, 175 could be classified into three immunotypes: A, B, and C. Each type was further divided into subtypes designated A1, A2, A3, B1, B2, B3, C1, and C2. Minor antigenic differences still exist within each subtype.

The two gonococcal isolates from each of 17 pairs of sexual contacts fell into the same subtype. Seventy-one of 73 isolates which required arginine, hypoxanthine, and uracil for growth (Arg-Hyx-Ura-) and seven of 107 other auxotypes belonged to subtypes A2 and A3. Marked geographical differences in distribution of gonococcal immunotypes were observed among those available for testing. Subtypes A2 and A3 were predominant in Seattle whereas types B and C were predominant in Southeast Asia. The only Arg-Hyx-Ura- isolates not belonging to subtypes A2 or A3 were the only two that were serum sensitive. This Micro-IF immunotyping appears potentially useful for future immunologic, epidemiologic, and genetic studies of N. gonorrhoeae.
The Incorporation of C3 Nephritic Factor (C3NeF) into a Stabilized C3 Convertase, C3bBb(C3NeF), and its Release after Decay of Convertase Function
Authors: Daha Mohamed R. , Austen K. Frank , Fearon Douglas T.
Published: December 2022

The stabilized fluid phase C3 convertase formed during the interaction of C3NeF, B, D̄, and C3 and isolated as a 10S complex by sucrose density gradient ultracentrifugation contains C3NeF. The C3NeF incorporated into the 10S complex cannot be detected by hemolytic assay until it is released during the decay of convertase function. The total recovery of the C3NeF present in the original reaction mixture from the 7S and 10S fractions indicates that the stabilizing action of C3NeF on the fluid phase convertase is not associated with an appreciable augmentation or decline in function. Furthermore, the C3NeF recovered after decay of the fluid phase convertase is identical to the starting material in its stabilizing action on erythrocyte-bound C3bBb, its molecular weight of 160,000 daltons, and its isoelectric point of pH 8.6 to 8.7. The incorporation of partially purified C3NeF into the fluid phase amplification convertase with release upon decay of the convertase, followed by removal of the contaminating complement proteins, yielded more than a 100-fold further purification. Thus, the affinity of C3NeF for the amplification convertase afforded a unique method for removing physicochemically similar contaminating proteins. Purified C3NeF, radiolabeled without decrement in functional activity, was incorporated in a 1:1 molar ratio with radiolabeled B into the 10S complex, thereby establishing a molecular composition of the stabilized convertase C3bBb-(C3NeF) of 1:1:1.
Expression of Fetal Antigens by Normal Human Skin Cells Grown in Tissue Culture
Authors: Thorpe William P. , Parker George A. , Rosenberg Steven A.
Published: December 2022

Normal human sera are capable of causing complement-mediated lysis of normal human skin cells grown in tissue culture. This lytic reactivity can be completely removed by absorption with first trimester fetal tissue. Absorption with a variety of normal adult human tissues including lymphocytes, decidua, skin, and muscle are incapable of absorbing reactivity. Absorption of reactivity by fetal tissue is specific and not due to the introduction of anti-complementary or other nonspecific factors, as evidenced by the inability of simultaneous fetal absorption to remove reactivity from antisera with specificity for HLA antigens. Similarly, absorption of lytic sera with fetal calf serum proteins was incapable of removing reactivity against normal cells in tissue culture. It thus appears that normal human cells in tissue culture express antigens shared by the first trimester human fetus, but not present on a variety of adult human tissues. This “neoantigen” present on normal human cells when grown in tissue culture is a potential source of confusion and must be accounted for in searching for human tumor-specific antigens utilizing tissue culture cells.
Expression of Protein HC on the Plasma Membrane of Different Human Cell Types
Authors: Pearlstein Edward , Turesson Ingemar , Tejler Lars , Grubb Anders O.
Published: December 2022

The surface expression of a recently described plasma glycoprotein called human complex-forming glycoprotein, heterogeneous in charge (protein HC) on a number of different human cell types was investigated. By means of direct and indirect immunofluoresence, protein HC was shown to be associated with the surface of virtually all cells of the investigated normal cell types including erythrocytes, peripheral blood B and T lymphocytes, and the human fibroblast lines HE 81, HE 31, and WI 38. When transformed and malignant cell populations were studied, it was found that some populations (e.g., the T cell line Molt-4) carried protein HC on the surfaces of very few cells, whereas other cell populations (e.g., chronic lymphocytic leukemia lymphocytes) carried the protein on most cells. Malignant cell populations with intermediary percentages of protein HC-positive cells were also found.

Protein HC on the cell surface of normal peripheral blood lymphocytes could be redistributed by incubation of the cells with anti-protein HC-antiserum at 37°C, and this reaction could be inhibited by sodium azide.
Selective Loss of Suppressor Cell Function in New Zealand Mice Induced by NTA
Authors: Klassen Lynell W. , Krakauer R. S. , Steinberg Alfred D.
Published: December 2022

New Zealand mice develop a naturally occurring thymocytotoxic antibody (NTA) which increases in titer with age. This antibody causes a loss of recirculating peripheral T cells and interferes with T cell functions. To study the potential pathogenic role of NTA in murine autoimmune disease, NZB/W mice were injected daily with NTA-containing serum starting at 3 to 5 days of age. Littermate controls received normal mouse serum (NMS). After 4.5 weeks of treatment, spleen cells from female NZB/W mice treated with NTA had a significant increase in capacity to induce graft-vs-host disease in newborn Swiss mice, suggesting a deficiency of suppressor cells.

Con A-activated spleen cells from NMS-treated animals suppressed IgM synthesis in vitro; however, Con A-activated spleen cells from NTA-treated mice were not suppressive. The NTA-induced loss of suppressor cell function was prevented by prior absorption of the NTA with thymocytes. Cells from control (NMS-treated) and NTA-treated litter-mates responded similarly to mitogens (Con A, PHA, PWM, LPS) and allogeneic lymphocytes in vitro. Although the number of nucleated spleen cells and splenic B cells was not changed by NTA treatment, a moderate reduction of T cells was seen (37% to 26% Thy 1.2 positive cells). Nevertheless, NTA treatment did not alter either skin allograft injection or the antibody response to immunization with the T-dependent antigen SRBC.

These studies suggest that NTA causes a selective loss of suppressor cells in NZB/W mice, supporting the hypothesis that NTA may play a pathogenic role in murine autoimmunity.