bluuebunny/crossref_metadata_2025 huggingface dataset:
Helper Factors
Authors: Howie Sarah , Feldmann Marc
Published: December 2022

The mechanism of action of murine antigen specific T cell helper factors to two synthetic polypeptide antigens under MHC control (GAT10 and (T,G)-A--L) has been analysed at the cellular level in vitro. Such factors stimulate antibody forming responses only in the presence of B cells and macrophages. Macrophages have binding sites for the factors and macrophages which have bound helper factor and antigen can activate macrophage depleted B cells in the absence of further factor or antigen. Ir gene defects have been located at the macrophage-B cell interaction in low responder strains of mice. Appropriate mouse anti-Ia sera block the binding of helper factors to macrophages indicating that the macrophage acceptor site may involve Ia antigens. The presence of Ir gene defects on B cells is currently being examined.
Macrophage Sensitivity to Endotoxin: Genetic Control by a Single Codominant Gene
Authors: Rosenstreich David L. , Vogel Stefanie N. , Jacques Allan R. , Wahl Larry M. , Oppenheim Joost J.
Published: December 2022

The effects of LPS on macrophages in vitro have been examined. LPS triggers macrophages to produce LAF and PGE2 in vitro. LPS is also cytotoxic for macrophages derived from LPS-sensitive mice and will significantly inhibit their phagocytic ability. Both LAF production and cytotoxicity are due to the direct effects of LPS on the macrophage and do not require the participation of lymphocytes. Each of these functions is abnormal in C3H/HeJ mice. The nature of the gene(s) controlling these macrophage responses to LPS has been determined. The response of (C3H/HeJ × C3H/HeN)F1 macrophages was intermediate when compared to the parental responses and no sex linkage was found. Backcross linkage analysis suggested that the same autosomal codominant gene controls both macrophage and B lymphocyte-LPS sensitivity.
Inhibition of the Immune Response by Membrane-Bound Antibody
Authors: Setcavage Thomas M. , Kim Yoon Berm
Published: December 2022

Cells from the spleens of “normal” swine, which were pretreated with pronase to remove surface membrane-bound immunoglobulin, gave an enhanced hemolytic plaque-forming cell response to sheep red blood cells in vitro in comparison with untreated controls. The enhancement could be abrogated by preincubating pronase-treated spleen cells in preparations containing antibody to sheep red blood cells. This effect was demonstrated by autologous sera, immune sera, and all three known classes of porcine serum immunoglobulins, including IgM, IgA, and IgG and could be removed by absorption with sheep red blood cells. Surface membrane-bound antibody exerted its effect by binding to the nonadherent cell population. The response of normal spleen cells was unaffected by antibody treatment. Pronase-treatment was not mitogenic, did not function as a polyclonal B cell activator, and did not selectively eliminate T or B cells. The results indicate that removal of antibody from the surface of lymphoid cells enhanced the humoral immune response in vitro and confirm that membrane-bound antibody can inhibit response to antigen.
Differential Sensitivity of Human Leukemic T Cell Lines and B Cell Lines to Growth Inhibition by Deoxyadenosine
Authors: Carson Dennis A. , Kaye Jonathan , Seegmiller J. E.
Published: December 2022

Previous experiments have suggested that the lymphospecific toxicity associated with inherited deficiencies of the enzymes adenosine deaminase (ADA) (adenosine aminohydrolase; EC 3.5.4.4) and purine nucleoside phosphorylase (PNP) (purine-nucleoside orthophosphate ribosyltransferase; EC 2.4.2.1) is mediated by toxic purine deoxyribonucleotides, which are selectively trapped in lymphoid tissues enriched in purine deoxyribonucleoside kinase. This hypothesis, however, does not fully explain the greater impairment of T as opposed to B cell functions seen in ADA and particularly PNP deficiency. In the present experiments we have compared the inhibitory effects of deoxyadenosine and adenosine, the natural substrates of ADA, on three leukemic T cell lines and three B cell lines in long-term tissue culture. The leukemic T cell lines were 20-fold more sensitive than the B cell lines to the toxic effects of deoxyadenosine, but not adenosine. In the presence of the ADA inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride, 2.6 µM deoxyadenosine inhibited leukemic T cell growth by 50%. The increased sensitivity of the T cell lines to deoxyadenosine was associated with the accumulation of intracellular deoxyadenosine triphosphate (deoxyATP), and with inhibition of DNA but not RNA synthesis. In both the T and B cell lines, deoxyadenosine toxicity could be reversed by the addition of deoxycytidine to the culture medium. Among other toxic compounds tested, the leukemic T cells were several-fold more sensitive than the B cells to thymidine, a known ribonucleotide reductase inhibitor. Thus leukemic T cells in vitro appear to be very susceptible to the toxic effects of ribonucleotide reductase inhibitors. Purine deoxyribonucleoside analogs that are not substrates for adenosine deaminase or purine nucleoside phosphorylase, and thymidine analogs that are not substrates for thymidine phosphorylase, may have potential value as T cell-selective chemotherapeutic agents.
Differences in Activation of Human and Guinea Pig Complement by Retroviruses
Authors: Bartholomew Richard M. , Esser Alfred F.
Published: December 2022

C type murine leukemia viruses (retroviruses) have been shown previously to possess a receptor for human C1 that activated human but not guinea pig complement. In the present study we provide evidence that the viral receptor also binds guinea pig C1 but that such binding does not lead to activation. However, incorporation of human C1s into guinea pig C1 to form a C1 hybrid results in activation of that hybrid and in viral lysis. In contrast, incorporation of guinea pig C1s into human C1 abolishes activation by the virus. These results demonstrate that C1s governs the activation of C1 of the viral receptor.
Thymic Macrophages Modulate One Stage of T Cell Differentiation in Vitro
Authors: Beller David I. , Unanue Emil R.
Published: December 2022

We have described a procedure for isolating thymic macrophages and have evaluated their activity in stimulating thymocyte maturation in vitro. The culturing of gradient-purified immature thymocytes on thymic macrophages leads to an increased expression of H-2 antigens and decreased lytic sensitivity with anti-TL and C. The macrophage-stimulated thymocyte also acquires the ability to respond in the MLR. We propose that the macrophage may regulate one stage of thymic differentiation in vivo.
Comparison of the Secondary Structures and Binding Sites of C-Reactive Protein and the Phosphorylcholine-Binding Murine Myeloma Proteins
Authors: Martin Young N. , Williams Ross E.
Published: December 2022

The circular dichroism (C.D.) spectrum of C-reactive protein in the 200- to 240-nm region indicates that the protein has a) a considerable content of α-helix, a feature not found in immunoglobulins, and, b) a very similar structure to amyloid P component. In the 240- to 320-nm region the two proteins have different CD spectra, and show little resemblance to the phosphorylcholine-binding murine myeloma proteins such as MOPC 167 IgA. Removal of calcium from C-reactive protein produced a large change in the 240- to 320-nm region attributable to tyrosine, and addition of phosphorylcholine produced a small change in the same region. Inhibition of the reaction of C-reactive protein with pneumococcal C substance by analogs of phosphorylcholine showed that C-reactive protein is much more specific for the phosphate moiety than the myeloma proteins. Despite these structural and binding-site differences, comparison of the amino-acid sequences of C-reactive protein and the hypervariable regions of the myeloma proteins suggests that the phosphorylcholine-binding sites of the two may still have features in common.
Plasmacytomas of the NZB Mouse
Authors: Morse Herbert C. , Riblet Roy , Asofsky Richard , Weigert Martin
Published: December 2022

Plasmacytomas were readily induced in NZB mice by three i.p. inoculations with pristane (2, 6, 10, 14-tetramethylpentadecane). In comparison with comparable induction regimens in BALB/c mice a) the latent period for plasmacytoma development was significantly longer in NZB's; b) the frequency of IgA paraproteins produced by NZB tumors was much reduced and that of IgG (IgG1, IgG2a, IgG2b, IgG3) was significantly increased; and c) the frequency of carbohydrate-binding paraproteins was 10-fold lower. There was a high frequency of primary ascites containing more than one paraprotein, but none of 25 such tumors produced more than one immunoglobulin class on serial transplantation.
Suppression of Cytotoxic T Lymphocytes by Carrageenan-Activated Macrophage-Like Cells
Authors: Yung Yee Pang , Cudkowicz Gustavo
Published: December 2022

In the presence of 100 µg/ml of carrageenans (CAR), B6D2F1 responder spleen cells failed to generate anti-parent or anti-allogeneic cytotoxic T lymphocytes in vitro, but instead generated suppressor cells. Cultured CAR-treated cells added to mixtures of B6D2F1 anti-B6 or B6D2F1 anti-C3H cytotoxic effectors (induced in vitro) and the appropriate 51Cr-labeled lymphoma targets reduced or abolished cytolysis (measured as 51Cr release) depending on the ratio of suppressor to effector cells. Cultured spleen cells not exposed to CAR failed to inhibit both types of cytotoxicity.

Presuppressor cells were associated with a splenic subpopulation independent of the thymus (i.e., present in spleens of athymic nude mice), were moderately adherent to Sephadex G-10 columns, but were not phagocytic or “sticky” to carbonyl iron particles. Activation of such cells by CAR was not prevented by in vitro exposure to 2000 rads of γ-rays before culture, nor facilitated by antigenic stimulation. The matured suppressor cells remained radioresistant and became strongly adherent to Sephadex G-10. The suppressors lacked surface Thy-1 alloantigen detectable by antibody and rabbit complement. Suppressor cell activity was not restricted by the immunologic specificity and major histocompatibility type of effectors.

It would thus appear that CAR induced the transition from the presuppressor to the suppressor state of a macrophage-like splenic subpopulation via maturation, differentiation, or cell injury. Cells of this type, capable of inhibiting the effector arm of cell-mediated responses, may well contribute to the regulation of natural and induced cytotoxic cell interactions.
Regulation of Antibody Response in Different Immunoglobulin Classes
Authors: Watanabe Takeshi , Kimoto Masao , Maruyama Seishin , Kishimoto Tadamitsu , Yamamura Yuichi
Published: December 2022

Establishment of a mouse T hybrid cell line secreting suppressor factor(s) specific for the IgE antibody response is described. Fusion was made with polyethyleneglycol between AKR-derived T lymphoma cells (BW5147) and T cells from mice sensitized with DNP-Mycobacterium. Treatment of spleen cells with nondialyzable factor(s) in the culture supernatants of the T cell hybrid clone, 26-M10, showed a suppressive effect on IgE formation but not on IgG formation in adoptive transfer experiments. The suppressive effect was exerted through inactivation of normal or antigen-primed B cells responsible for IgE formation. It was also shown by direct cytotoxic test that the hybrid cells expressed H-2 and Thy-1 antigens derived from both parental cells on their surface. Karyotype analysis of the hybrid cells revealed that the number of chromosomes was less than the sum of the two parental cells' and the average was 50 (45 to 55). Although the 26-M10 hybrid cells lost the ability to secrete active suppressive factor(s) into culture medium 21 weeks after hybridization when the number of chromosomes in most of the cells was less than 41, recloning of the 26-M10 cells successfully recovered active suppressive clones.
Generation of Cytotoxic Lymphocytes in the Autologous Mixed Lymphocyte Culture
Authors: Miller Richard A. , Kaplan Henry S.
Published: December 2022

We have studied the ability of purified B lymphocytes to generate cytotoxic T lymphocytes in autologous mixed leukocyte cultures (MLC). Cytotoxic lymphocytes were produced but only autologous mononuclear cells stimulated by lipopolysaccharide (LPS) were susceptible target cells. Unstimulated mononuclear cells and purified B cells were not susceptible to killing by cytotoxic cells generated in the autologous MLC. This suggests that the target antigen may be expressed on stimulated or dividing B lymphocytes in a way that renders the cells more susceptible to cytolysis. Autologously stimulated cytotoxic effector cells were found to exhibit specificity. Cytotoxicity for autologous LPS-stimulated target cells occurred but not for an allogeneic, B cell, histiocytic lymphoma cell line. It is postulated that cytotoxic T cells generated in the autologous MLC may play a role in immune surveillance or in regulation of the immune system.
The Effects of Anti-IgD on Serum Immunoglobulins, Antibody Production, and Immunoglobulin-Bearing Cells in Adult Rats
Authors: Cuchens Marvin A. , Martin Louis N. , Leslie Gerrie A.
Published: December 2022

Rabbit anti-rat IgD (δ-specific) injected subcutaneously into adult rats resulted in hypergammaglobulinemia, increased serum immunoglobulins, increased antibody production, and alterations in the percentages of PBL expressing IgD and IgM. Serum IgM, IgG2a and IgG2c concentrations were increased 100%, 125%, and 200%, respectively, over controls, whereas IgA levels were not altered. Increases in the serum immunoglobulins were predominately due to an increase in antibodies to the rabbit serum components. A depletion of IgD-IgM bearing lymphocytes in the peripheral blood was observed after 24 hr of injection. Percentages of IgD-IgM bearing lymphocytes returned to normal by day 4 and were significantly increased (∼2-fold) by day 8. The in vivo effects of anti-δ in rats were similar to those reported in the monkey. Possible modes of action of the anti-δ and the significance of these results in relation to the biologic function of membrane IgD are discussed.
Induction of Lymphocyte Colony Formation in Vitro by Protein A
Authors: Shibasaki Masanao , Nemoto Hirobumi , Suzuki Shigeyoshi , Kuroume Takayoshi
Published: December 2022

Human lymphocyte colonies were grown in semi-solid culture in the presence of staphylococcal protein A. The best results were obtained when 1 × 106 lymphocytes were cultured for 5 to 7 days with 25 to 50 µg of protein A per dish. A lineal relationship was observed between the number of cells seeded and the number of colonies developed. An increased number of colonies was seen in cord blood culture compared with that in child and adult peripheral blood. The addition of 5 × 10-5 M of 2-ME to the culture approximately doubled the colony counts. The cells harvested from the colonies contained about 70% of E-RFC and 20% of EAC-RFC.
The Mouse Mutant “Motheaten”
Authors: Sidman Charles L. , Shultz Leonard D. , Unanue Emil R.
Published: December 2022

Motheaten mice have normal levels of T lymphocytes but reduced levels of B lymphocytes. Those B cells that are present show an impaired proliferative response to B cell mitogens and no plaque-forming cell response to thymus-independent antigens. T lymphocyte function is also defective in motheaten mice, as assayed by the proliferative responses to T cell mitogens, and by the capacity to develop cytotoxic killer cells against allogeneic cells. Motheaten mice possess spleen cells capable of suppressing normal B cell responses to thymus-independent antigens. This suppressor cell is not sensitive to anti-Thy-1 antibody plus complement treatment but is partially removed by adherence on plastic. Overall, the motheaten mouse suffers a functional severe combined immunodeficiency of both B and T cells, even though these cells are present. We postulate that the inescapable lethality of the motheaten defect is due to the lack of immunocompetence during the critical developmental period before adulthood and perhaps to an autoaggressive component as well.
Development of IgE-Forming Cells in Vitro from Rat Mesenteric Lymph Node Cells
Authors: Suemura Masaki , Urban Joseph F. , Ishizaka Kimishige
Published: December 2022

Mesenteric lymph node cells from normal rats and rats infected with Nippostrongylus brasiliensis (Nb) were cultured with pokeweed mitogen (PWM) or Nb antigen, and the development of IgM-, IgG2a-, or IgE-containing cells was assessed by immunofluorescence. Normal lymph node cells stimulated with PWM developed into both IgM- and IgE-containing cells, whereas similar stimulation of cells from Nb-infected rats resulted in the development of IgM-, IgG2a-, and IgE-containing cells. The in vitro plasma cell response to PWM was dependent on the presence of T lymphocytes. Lymph node cells from Nb-infected rats responded to Nb antigen and developed into plasma cells of IgM, IgG, and IgE classes. The response was antigen specific and required antigen-primed T cells. Depletion of IgE-bearing cells of IgM-bearing cells before stimulation with either PWM or Nb antigen diminished the level of IgE-forming cell development, suggesting that IgE-IgM double bearing cells are precursors of IgE-forming cells. The distribution of the three isotypes among the Ig-forming cells that developed in response to PWM was influenced by the source of both B and T cells. When B cells from Nb-infected rats were employed as a source of precursors, T cells from infected animals were more effective than normal T cells for the development of IgE-forming cells, whereas the latter cells were more effective for the development of IgG2a-forming cells than T cells from infected animals.
Sequential Proliferation Induced in Human Peripheral Blood Lymphocytes by Mitogens
Authors: Winger Larry A. , Nowell Peter C. , Daniele Ronald P.
Published: December 2022

The addition of PHA-stimulated human lymphocytes inhibits the continued proliferation of autologous lymphocytes growing in a feeder-layer system in response to mitogen. Velocity sedimentation and 3HTdR autoradiographic studies of the suppressive population indicated that the effect is mediated by proliferating, large cells (“blasts”). Other populations of actively dividing cells, including normal lymphocytes stimulated with pokeweed mitogen or the calcium ionophore A23187, the Raji B cell line, and human and mouse fibroblasts, suppressed 3HTdR uptake as well, in a similar dose range. The suppressive effect of these cells could be roughly correlated with the proportion of blasts in the cell population.

Inhibitory activity in this system was not demonstrated in supernatants from PHA blasts compared to saline controls, but intact cells suppressed across a nucleopore membrane but not a dialysis membrane. Supplementing the assay culture with low m.w. constituents of the medium did not decrease the suppressive effect. However, when fresh serum was added in increasing concentrations with the inhibitory cells, their suppressive effect was partially abrogated.

These results may be interpreted in at least two ways that are not mutually exclusive: i) PHA blasts may elaborate a labile inhibitory substance that may be bound, inactivated, or degraded to some degree by serum and/or ii) actively proliferating cells may exhaust an essential high m.w. nutrient in the assay culture. It is likely that the inhibitory effects observed in many culture systems involving mitogen-induced suppressor lymphocytes are not restricted to immunologic phenomena but may include a more general function of actively dividing cells, which is neither tissue nor species specific.
Immune Response to a Mammary Adenocarcinoma
Authors: Huber S. A. , Lucas Z. J.
Published: December 2022

Sera from Fischer rats 3 to 13 days after i.p. injection of syngeneic 13762A mammary adenocarcinoma contain three factors specifically blocking cell-mediated cytotoxicity (CMC). The major blocking factor is a 160,000-dalton IgG that combines specifically to cytolytic lymphocytes but not to tumor cells or tumor antigen, and that is not dissociated after treatment with 8 M urea. The other factors have been putatively identified as tumor antigen (<70,000 daltons) and as soluble antigen-antibody complexes (>200,000 daltons). Injecting the tumor antigen into tumor-free rats induced spleen cells specifically cytotoxic to the 13762A tumor and provided partial protection to challenge with live tumor cells. Treating soluble antigen-antibody complexes with 8 M urea decreased the size of the blocking activity from greater than 200,000 to less than 70,000 daltons. Although the IgG fraction dissociated from the complex did not block CMC, it did recombine with the tumor antigen fraction to transfer activity to the >200,000-dalton fraction. In contrast, mixing tumor antigen with the IgG fraction that did block CMC did not alter the size of the blocking activities.
Complement Lysis: Evidence for an Amphiphilic Nature of the Terminal Membrane C5b-9 Complex of Human Complement
Authors: Bhakdi Sucharit , Bjerrum Ole J. , Bhakdi-Lehnen Birgit , Tranum-Jensen Jørgen
Published: December 2022

The terminal, membrane-derived C5b-9 complex of human complement (C) is an apparently hollow, cylindrical macromolecule vertically oriented on the target membrane. In the present study, an antiserum to the complex has been used to probe its immunobiochemical properties. “Neoantigenic” determinants characteristic of the complex have been detected, which are absent on native C5-C9 molecules. Evidence that the C5b-9 complex is an amphiphilic molecule that possesses apolar, detergent-binding surfaces has been obtained by using charge-shift crossed immunoelectrophoresis, and by direct demonstration of Triton X-100 binding to the complex in quantitative immunoelectrophoresis. By the same criteria, serum C5, C6, and C9 are hydrophilic molecules. The results indicate that assembly of C5-C9 into the terminal membrane C5b-9 complex is accompanied by conformational changes in the individual C components that lead to the exposure of apolar molecular regions in the complex. It is proposed that this constitutes the basis for the lipid-binding properties of the macromolecule, which enable it to become inserted into biologic and artificial lipid membranes with apparent generation of a transmembrane pore.
The Binding of Activated C3 to Polysaccharides and Immunoglobulins
Authors: Capel Peter J. A. , Groeneboer Oscarina , Grosveld Gerard , Pondman Karel W.
Published: December 2022

The nature of the acceptors for activated C3 present on immunoglobulins was studied by using the fixation of C3 to Sepharose beads after activation with trypsin as a model system. C3 fixation to Sepharose is a property exclusively linked to the short active state of C3. This binding could be inhibited by various carbohydrates and their affinity for C3 was calculated from the extent of the inhibition of the binding of C3 to Sepharose. Mono-, di-, tri- and tetrasaccharides showed on a molar basis an increasing but still weak affinity for active C3. The C3 fixation to Sepharose could be inhibited by immunoglobulins and the degree of inhibition was proportional to the hexose content of the immunoglobulin preparations. The isolated polysaccharide moiety of IgG gave the same inhibition as the intact IgG.

In addition cell wall polysaccharides of Salmonella abortus equi were found to have a high affinity for active C3. Thus, the more complex polysaccharides such as those present on immunoglobulins and cell walls might function as acceptor for activated C3.
Suppressor Adherent Cells in Human Tuberculosis
Authors: Ellner Jerrold J.
Published: December 2022

Patients with newly diagnosed active pulmonary tuberculosis were divided into high and low responder groups on the basis of 3H-thymidine incorporation of peripheral blood mononuclear cells (PB MNC) induced by tuberculin-purified protein derivative (PPD). The group of patients with low tuberculin responses was characterized by anergy to tuberculin skin testing and larger numbers of circulating monocytes than the high responders. The groups were comparable in the extent of pulmonary tuberculosis and other clinical parameters. PB MNC from tuberculin low responders had normal phytohemagglutinin (PHA) but depressed streptokinase-streptodornase (SKSD), Candida antigen, and tetanus toxoid-induced 3H-thymidine incorporation. Depletion of adherent cells resulted in a mean 24.4-fold enhancement of T lymphocyte responses to PPD in the low responders as compared to a 2.9-fold increase in the high responders. The low response of PB MNC from low responders to nonmycobacterial antigens was not similarly augmented by adherent cell depletion. Adding back graded numbers of adherent cells to purified T lymphocyte populations resulted in greater depression of the PPD-induced proliferative response to the tuberculin low responders when compared to the high responders. These studies provide evidence for circulating suppressor adherent cells in tuberculosis patients with diminished responsiveness to PPD in vitro. This immunosuppression is not mediated by adherent cell supernatant products, nor does it involve T lymphocyte labile during culture. However, complex cellular interactions, possibly involving suppressor T cells, are implicated by the restriction of this phenomenon to PPD-induced lymphocyte activation and the depression of the PB MNC responses to nonmycobacterial antigens. The suppressor adherent cells defined in these studies may be relevant as a cause or consequence of infection in a subset of patients with tuberculosis.
Specificities of Killing by T Lymphocytes Generated against Syngeneic SV40 Transformants: Studies Employing Recombinants within the H-2 Complex
Authors: Gooding Linda R.
Published: December 2022

T lymphocyte effectors to syngeneic SV40-transformed cells, generated by secondary in vitro sensitization of immune spleen cells, lyse SV40 transformed targets that are syngeneic at the H-2 locus. In this study we have employed recombinants within the H-2 region to examine in detail this H-2 specificity. H-2b effector were found to lyse SV40-transformed targets from recombinants bearing either H-2Kb or H-2Db. H-2k effectors recognized only SV40-transformed H-2Kk, and not H-2Dk target cells. By using the same protocol for sensitization, no effector cells could be detected in H-2d mice. Effectors generated in H-2 recombinant mice showed that the response capacity resides with K and D. For example, HTG, which is H-2d except at the D locus (H-2Db), produced effector cells specific for SV40-transformed H-2Db targets. Thus, the secondary in vitro response to SV40 transformants was found to depend only on the K and D alleles and not to be modified by the I region to any measurable extent.
Macromolecular Insoluble Cold Globulin (MICG): A Novel Protein from Mouse Lymphocytes
Authors: Kansu Emin , Sobczak Gloria , Hauptman Stephen P.
Published: December 2022

In the present communication we have examined the relationship between the synthesis of macromolecular insoluble cold globulin (MICG) and the mixed lymphocyte reaction (MLR). In addition, we have studied in vivo the effect of antiserum to MICG on the antibody response to sheep red blood cells. The experiments indicate that MICG synthesis compared to either IgM or total protein is selectively stimulated in responder T cells exposed to allogeneic stimulator cells in the MLR. Furthermore, cytotoxicity studies utilizing anti-MICG antiserum demonstrated that T cells bearing MICG on their surface are an essential component of the responder cell population in the MLR.

In vivo administration of antiserum to MICG significantly suppressed both the primary and secondary antibody response to sheep red blood cells. A possible mechanism for this suppression is discussed.
Solid Phase Radioimmunoassay for Quantitation of Antigen-Specific IgG in Human Sera with 125I-Protein A from Staphylococcus Aureus
Authors: Hamilton Robert G. , Sobotka Anne K. , Adkinson N. Franklin
Published: December 2022

Radiolabeled protein A from Staphylococcus aureus (Staph A) has been used to develop a solid phase, noncompetitive radioimmunoassay for quantitation of specific IgG antibody. The assay involves two incubations: First, agarose-insolubilized antigen is mixed with serum samples for 1 to 4 hr during which specific antibody is bound; second, after a washing procedure, the solid phase immune complexes are incubated for 4 to 18 hr with 125I-Staph A, during which the radiolabeled detection protein binds to the insolubilized specific IgG antibody. In a comparative study of the IgG antiphospholipase A antibody content of 23 human sera drawn from honeybee venom-sensitive patients, results of the Staph A assay correlated highly (r = 0.981, p < 0.001, N = 23) with those obtained from a liquid phase, competitive radioimmunoprecipitation (double antibody) assay. The two assays demonstrated comparable precision, sensitivity, and reproducibility. In contrast, the use of 125I-Staph A in the solid phase radioimmunoassay was supperior to 125I rabbit anti-human IgG because of lower negative serum (blank) values, shorter time required to reach equilibrium binding, and greater precision and reproducibility. In principle, the 125I Staph A assay may be applied to IgG quantitation for crude allergen extracts as well as purified antigens. Furthermore, the sera of a number of mammalian species may be studied without further modification.
The Role of Monocytes in Human Lymphocytes Activation by Mitogens
Authors: de Vries Jan E. , Caviles Alendry P. , Bont Willy S. , Mendelsohn John
Published: December 2022

Studies were performed to determine the role of monocytes in human lymphocyte activation by mitogens. Velocity sedimentation at 1 × G in a new apparatus was utilized to obtain highly purified lymphocyte fractions (LF) nearly free of monocytes (0.02 to 0.4%) and a fraction (MF) enriched for monocytes (64 to 92%). The average peak responses of the lymphocyte fractions to phytohemagglutinin, concanavalin A, and pokeweed mitogen were 19, 10, and 9% of the responses achieved with unfractionated lymphocyte cultures containing approximately 20% monocytes. These changes were not attributable to altered dose requirements. When mitomycin-C-treated MF cells were used to reconstitute LF cultures, it was found that 4% monocytes fully restored the response to phytohemagglutinin whereas 8 to 16% monocytes were required for a normal response to the other mitogens. Higher numbers of MF cells produced supranormal responses, with 35 to 50% monocytes resulting in the optimal stimulation. Allogeneic monocytes were able to fully reconstitute the response of LF, and 2-mercaptoethanol (50 µM) was only slightly effective.

In exploring possible mechanisms by which monocytes potentiate the mitogenic activity of lymphocytes, it was found that the supernatants of MF cultures could partially, but not completely, reconstitute LF responses, suggesting that contact with MF may be required for optimal effectiveness. Addition of graded numbers of monocytes to LF altered both the kinetics of the response and the peak level of proliferation. Monocyte depletion also resulted in markedly decreased survival of cultured unstimulated LF. These observations suggest a variety of possible effects of monocytes in potentiating mitogenic responses, including contact-mediated interactions with lymphocytes (possibly to present the mitogen optimally); enhancement of proliferation kinetics and the size of the responding subpopulation, and maintenance of a requisite growth factor(s) in the culture. Small differences in the monocyte content of cultured lymphocyte preparations may thus account for many of the often observed variations in mitogen responsiveness.
Role of Different T Cell Sets in the Rejection of Syngeneic Chemically Induced Tumors
Authors: Shimizu Kazuyuki , Shen Fung-Win
Published: December 2022

This study was designed to investigate the phenotypes of immune cells concerned in the rejection of chemically induced tumors. Counted numbers of viable dissociated cells of a selected C57BL/6 (B6) tumor were combined with counted numbers of peritoneal cells from highly immunized syngeneic B6 donors and inoculated subcutaneously into untreated syngeneic B6 mice. Progressive tumor growth was prevented by nonadherent immune peritoneal cells in numbers less than one-quarter the number of tumor cells, and the cells responsible belonged mainly or entirely to the nonadherent fraction of the peritoneal population. There was no cross-protection between this tumor and a second B6 tumor induced by the same carcinogen, indicating that immunity in this experimental system, as reported previously, is directed to antigens that individually characterize chemically induced tumors. Elimination of Thy-1(+) cells by Thy-1 antiserum and complement abolished the protective capacity of the immune peritoneal cells, showing that immunity under these conditions is mediated by T cells. Protection was also precluded by elimination of Lyt-1(+) cells or of Lyt-2(+) cells, showing that protection could not be attributed to either the Lyt-23 or the Lyt-1 set of T cells alone. Nor was protection conferred by various combinations of these selected Lyt-1 and Lyt-23 cell sets. Thus, participation of the third well defined Lyt cells set, Lyt-123, which is automatically eliminated when the Lyt-23 and Lyt-1 sets are prepared by selective immune cytolysis is evidently necessary to rejection, in these experimental circumstances. Although this might imply that cytotoxicity for syngeneic tumors is effected by Lyt-123 cells, it is emphasized that this assay system allows time for the differentiation and proliferation of cells sets. Thus, the data are also consistent with a uniform hypothesis that cell-mediated cytotoxicity is an exclusive function of Lyt123:CS cells, and that these, and possible Lyt1:H amplifier cells, are generated in the course of the assay from a specifically primed antecedent Lyt123:ARC cell set.
Lymphocyte Soluble Factor-Activated Cell-Mediated Cytotoxicity: The Role of Ia-Like Antigens in Activation and Cytolysis, and Their Relationship to Fc Receptor
Authors: Kasakura Shinpei
Published: December 2022

Rabbit antisera to the human B cell-specific surface antigen complex (27,000 and 33,000 m.w.) have been employed to investigate the role of Ia-like antigens in cell-mediated lympholysis induced by supernatants from cultures of human peripheral blood lymphocytes. A single treatment of T lymphocytes with anti-B cell serum plus complement totally eliminated CFM-induced CML. Decomplemented antiserum or IgG F(ab′)2 fragments present during the 6-day culture period blocked the generation of cytotoxic effector cells. Furthermore, cytotoxicity was inhibited by simply pretreating T lymphocytes with either decomplemented antiserum of F(ab′)2 fragments before exposure to CFM. The blocking effects of these antisera or their derivatives were also shown to occur during the cytolytic phase of CFM-induced CML. The effector cell in this type of cytotoxicity is known to possess receptors for the Fc portion of IgG. However, that this inhibitory effect was not due to binding of antibodies to the Fc receptor was shown in studies that demonstrate that F(ab′)2 fragments of these antisera inhibited cytotoxicity but did not interfere with EA rosette formation. This was further supported by the demonstration that pretreatment of the T lymphocyte with aggregated γ-globulin abrogated EA rosette formation but did not suppress cytotoxicity. Thus, the following information has been obtained from these studies: 1) Both the precursors of cytotoxic cells and the cytotoxic cell itself in CFM-induced CML bear Ia-like antigens; 2) Ia-like antigens are necessary in both the sensitization and cytolytic phases of this cytotoxicity; and 3) the Ia-like antigen represents a cell surface site on the effector cell that is distinct from the Fc receptor.
Suppression of Cytotoxic Response to Histoincompatible Cells
Authors: Gorczynski Reginald M. , MacRae S.
Published: December 2022

Spleen and thymus cell populations from normal or allograft tolerant mice have been cultured for 5 days with specific alloantigens and examined for their reactivity in three assay systems. No consistent correlation was observed between the production of cytotoxic T cells (CTL) in these cultures and the ability of such cultured cells to inhibit specifically a CML response from fresh normal spleen cells directed to the priming alloantigens. Furthermore, suppressor cells measured in this latter assay were apparently distinct from those able to inhibit the production of cytotoxic lymphocyte precursors (CTLp) from bone marrow stem cells in lethally irradiated bone marrow protected mice. Velocity sedimentation experiments confirmed that both the precursor and effector cells for the two suppressor systems were physically separable, and were distinct from CTLp or CTL, respectively. Precursor cells for the two suppressor systems investigated belong to the short-lived cortical thymus cell population.
Induction of Suppressor Cells in Rat Spleen: Influence of Microbial Stimulation
Authors: Mattingly Jerome A. , Eardley Diane D. , Kemp John D. , Gershon Richard K.
Published: December 2022

The role of the products of prostaglandin synthetase in the suppression of in vitro secondary antibody responses by rat spleen cells was examined. By including cells from both germfree and conventional rats in these studies, the effect of in vivo microbial stimulation on this suppression was also determined. We found that 1) the suppression that is normally present in the spleen cells of rats can be eliminated by the use of glass wool or indomethacin; 2) germfree rats do not display this suppressor activity; and 3) this “deficit” in the germfree rat may be due to a lack of a microbial-induced signal from a nonadherent cell to an adherent prostaglandin-containing macrophage, implying that at least two cells are involved in the prostaglandin-synthetase dependent suppressor effect. It is possible that large amounts of some or all microbial products activate “suppressor” macrophages and that inbred rats behave like “chronically infected” mice because of an inability to regulate their “normal” microbial flora.
Tumor Antigens as Inappropriately Expressed Normal Alloantigens
Authors: Russell John H. , Ginns Leo C. , Terres Geronimo , Eisen Herman N.
Published: December 2022

Preliminary tests of three BALB/c myeloma tumors for ability to elicit immune responses in BALB/c mice showed that the only highly immunogenic one was MOPC-167. BALB/c mice immunized with this tumor developed cytotoxic T lymphocytes (CTLs) that lysed MOPC-167 cells specifically. When challenged with 5 × 105 MOPC-167 cells (about 1000 times the LD50 dose) labeled with 131I-iododeoxyuridine, tumors failed to develop in immunized animals and whole-body counts showed that the labeled MOPC-167 cells were rapidly eliminated. The cross-reactions of these CTL were unusual: they caused essentially no lysis of eight other BALB/c tumors, including three myeloma tumors, but they lysed extensively six out of nine tumors of DBA/2 mice (a seventh was lysed weakly). In contrast, the CTL elicited by MOPC-167 in (BALB/c × DBA/2)F1 hybrids did not lyse P815, the most sensitive of the DBA/2 tumors, and had less lytic activity against MOPC-167. CTL elicited by MOPC-167 in other BALB/c hybrids (BALB/c × NZB and BALB/c × C57BL/6) had the same reactions and cross-reactions as those elicited in purebred BALB/c mice. All of these observations suggest that MOPC-167 expresses an alloantigen that normally is absent in BALB/c mice but present in DBA/2 mice and in many DBA/2 tumors. The possibility that CTL elicited by immunization with a syngeneic tumor might be directed to inappropriately expressed alloantigens on the tumor cells was supported by observations with L5178Y: this lymphoma was one of the DBA/2 tumors not lysed by BALB/c anti-MOPC-167 CTL, but it was lysed by the CTL elicited in DBA/2 mice with MOPC-167 or with normal BALB/c spleen cells. Hence L5178Y, although of DBA/2 origin, appears to express antigens that are the same or strongly cross-reactive with an alloantigen that is absent in DBA/2 mice and present on normal BALB/c spleen cells and on a BALB/c myeloma tumor (MOPC-167).
Detection of HLA-DRw (Ia-Like) Antigens on Human T Lymphocytes Grown in Tissue Culture
Authors: Metzgar Richard S. , Bertoglio Jacques , Anderson Joy K. , Bonnard Guy D. , Ruscetti Francis W.
Published: December 2022

Human T lymphocytes that proliferate in the presence of conditioned medium from PHA-stimulated allogeneic peripheral blood cells were shown to express Ia antigens after the 8th culture day. Ia antigens as detected by xenogeneic antisera were present on 80 to 90% of the cultured cells which were also strongly reactive with xenogenic antisera defining a human T cell antigen and formed E rosettes. Control cultures with PHA or no conditioned medium expressed T cell but not Ia antigens. These cultured T cells also express the same HLA-DRw determinant as the B cells of the donor they were derived from. Absorption of xenogeneic Ia, and HLA-DRw alloantisera with cultured T cells completely removed the reactivity of these sera for enriched peripheral blood B lymphocytes from normal donors.
Relationship Between Antibody Affinity and Hemolytic Plaque Diameter
Authors: DeHeer David H. , Edgington Thomas S.
Published: December 2022

The relationship between antibody affinity and hemolytic plaque diameter was explored with immunochemically purified anti-DNP antibody of demonstrated affinity and heterogeneity. Anti-DNP antisera were prepared by immunizing two groups of two rabbits each with 5 and 50 mg of DNP-BGG, respectively. Anti-DNP IgG antibody from each antiserum was purified by ammonium sulfate precipitation, DEAE cellulose and Sephadex G-200 chromatography, and elution from a DNP-aminoethylcellulose immunoabsorbent. The affinity and heterogeneity of each preparation were determined by equilibrium dialysis with 3H-DNP-EACA. Each antibody preparation was analyzed by hemolytic plaque assay with trinitrophenylated sheep erythrocytes in an agarose layer. These assays demonstrated a proportionality between antibody affinity and plaque diameter, with the largest plaques being formed by antibody of high affinity. Incorporation of free DNP-EACA into the assays demonstrated: a) that the highest affinity plaques were neutralized more efficiently than low affinity plaques; b) high affinity antibody resulted in a higher inhibition slope than low affinity antibody; c) inhibition slope was directly proportional to the heterogeneity of antibody affinity; and d) a linear correlation existed between the concentration of competing antigen that neutralized 50% of the antibody (Ab50) and the affinity of the antibody. These results provide a basis for the experimental use of inhibition assays to assess anti-hapten antibody affinity and substantiate the validity of using Ab50 in analyses of relative antibody affinity.
Involvement of Proteases in the Binding of EAC14OXY23B to Complement Receptor Cells
Authors: Dierich Manfred P. , Landen Beate
Published: December 2022

Involvement of proteases in complement-dependent rosette formation was tested by using binding of EAC14oxy23b to complement receptor cells (CR+C) as a model. The evidence for such a mechanism was 4-fold: a) Interaction between EAC14oxy23b and CR+C (Raji cells, PBL, PMNL) could be inhibited by DFP, PMSF, or TLCK; pretreatment of EAC14oxy23b by the inhibitors had the same effect. b) EAC43b and EAC143b showed less rosettes than EAC14oxy23b, an effect for which oxyC2 could be made directly responsible; the oxyC2a-dependent increase in reactivity could be avoided by DFP. c) Inhibitor-induced reduction and oxyC2a-induced promotion of cell interaction could be correlated with reduction or promotion of the hemolytic activity of EAC14oxy23b toward C5. d) Treatment of Raji cells with a monospecific anti-C3 serum resulted in inhibition of the oxyC2-dependent part of the interaction.

The enzyme-dependent mechanism started to function only after the protease-carrying cell (EAC14oxy23b) and the substrate-carrying cell (e.g., Raji cell) were brought into close enough contact via interaction between C3b and C3-receptors. This suggests that after the initial nonenzymatic contact through interaction of C3 and C3-receptor or possibly other ligand-receptor cooperation, membrane-bound proteases might be enabled to cleave suitable substrates on the adjacent cell and to liberate new binding sites on the substrates. These new binding sites might then intensify or stabilize an otherwise labile cell-cell contact.
Rhesus Monkey B Lymphocyte Surface Immunoglobulin: Analysis with a Fluorescence-Activated Cell Sorter
Authors: Finkelman Fred D. , Scher Irwin
Published: December 2022

Rhesus monkey spleen, mesenteric lymph node, peripheral lymph node, blood, thymus, and bone marrow mononuclear cell suspensions were stained with fluorescein-conjugated F(ab′)2 fragments of affinity-purified rabbit anti-human Fab, rabbit anti-human γ, rabbit anti-human µ, rabbit anti-human δ, and/or rabbit anti-human α as well as rabbit anti-keyhole limpet hemocyanin (RaKLH) and analyzed for fluorescence intensity and frequency of positive cells with a fluorescence-activated cell sorter. Greater than 90% of surface (s)IgM-bearing spleen, blood, and lymph node lymphocytes bore sIgD, whereas only approximately 40% of sIgM-bearing bone marrow lymphocytes had sIgD. In all of these organs greater than 90% of sIgD-bearing cells also had sIgM. Substantially smaller numbers of lymphocytes bore sIgG than sIgM or sIgD, and most sIgG-bearing cells in all organs studied lacked sIgM and sIgD. Few if any cells in any organ studied bore detectable sIgA, and less than 1% of thymus cells had any sIg.

B cell populations from spleen, peripheral lymph node, and mesenteric lymph node averaged similar quantities of sIgM and sIgD per B cell. Blood B cells averaged twice as much sIgM and sIgD as B cells from spleen and lymph node, and 9 times as much sIgD as sIgD+ bone marrow cells. sIgD+ bone marrow B lymphocytes have considerably more sIgM than sIgD- sIgM+ bone marrow B cells. Our data confirm that the sIgD+ sIgM+ cells are the predominant B lymphocyte in primates, and suggest that monkey B cells acquire sIgD in the marrow before migrating to other lymphoid organs.
A Physicochemical and Immunologic Comparison of the Cell Growth Inhibitory Activity of Human Lymphotoxins and Interferons in vitro
Authors: Ware Carl F. , Granger Gale A.
Published: December 2022

The physicochemical, immunologic, and biologic relationships between human lymphotoxins (LT) and interferons (IF) present in supernatant fluids from lectin-stimulated peripheral blood lymphocytes (PBL) and a continuous B-lymphoblastoid cell line (PGLC-33h) were analyzed. LT activity obtained from lectin-activated PBL could not be resolved from IF activity by gel filtration chromatography. LT activity eluted in multiple peaks of activity at 70 to 90,000, and 40 to 50,000 m.w., characteristic of α and β LT, respectively. IF activity in these supernatant fluids eluted as a broad band between 35 and 80,000 m.w., also suggestive of molecular heterogeneity. In contrast, this m.w. heterogeneity was not observed in LT and IF activities obtained from the PGLC-33h cell line. LT and IF eluted as separate peaks of activity at 90,000 and 25,000 m.w., respectively. In addition, acid and heat lability of PGLC-33h IF suggested similarity to type II IF. Immunologic studies, with a rabbit anti-α class serum that neutralized LT activity from both PBL and PGLC-33h, did not affect IF activity from either of these sources.

Supernatant fluids from PGLC-33h cultures were also capable of inhibiting the proliferation of HeLa cells in vitro. The growth inhibitory activity was attributed to LT- and IF-like molecules. This evidence suggests that although cytotoxic and anti-viral activities were due to separate molecules, LT and IF have overlapping biologic activities in their ability to inhibit the proliferation of cells in vitro.