bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribution of Lyb 5+ and Lyb 5- B cells to the primary and secondary phosphocholine-specific antibody response.
Authors: Kenny J J , Yaffe L J , Ahmed A , Metcalf E S
Published: December 2022

Due to a mutation on their X-chromosome, CBA/N mice lack the Lyb-5+ subset of B cells. The loss of this B cell subset results in a profound alteration in the immune response of these mice to the hapten phosphocholine (PC). Thus, when these mice are immunized with high doses of PC-KLH (200 micrograms) in CFA, they: 1) fail to produce IgM anti-PC antibodies; 2) produce little or no anti-PC antibody bearing the normally predominant T15-idiotype; and 3) produce IgG anti-PC antibodies only late in the primary response. In order to more fully delineate this defect in responsiveness to PC, the splenic focus assay was used to analyze Lyb-5- B cell precursors from both normal and immune defective mice. Lyb-5- cells were obtained from normal (CBA/N x DBA/2)F1 (CD) female spleens by treatment with anti-Lyb-5 serum and complement. These normal Lyb-5- cells and Lyb-5- cells from immune defective CD male mice were stimulated in vitro with either PC-Hy or TNP-Hy in the presence of Hy-primed T helper cells. The results demonstrate that primary Lyb-5- PC-specific B cells fail to respond in the splenic focus assay, while secondary Lyb-5- PC-specific precursors respond normally, and that both primary and secondary Lyb-5- TNP-specific precursors respond in the splenic focus assay. These data suggest that Lyb-5- PC-specific precursors must differentiate into memory cells before they can be activated to secrete antibody, and they also indicate that the Lyb-5- B cell subset may be composed of two subsets with different activation requirements.
The role of B cell proliferation in the generation of immunoglobulin-secreting cells in man.
Authors: Jelinek D F , Lipsky P E
Published: December 2022

The relationship of B cell proliferation and the generation of immunoglobulin-secreting cells (ISC) was explored in vitro by examining the effect of hydroxyurea (HU), an inhibitor of cellular DNA synthesis, on the generation of ISC from human peripheral blood mononuclear cells (PBM). HU completely inhibited the capacity of PBM to generate ISC in response to pokeweed mitogen (PWM) and other polyclonal B cell activators. Inhibition resulted from an effect on B cell proliferation, because HU also prevented the generation of ISC in cultures of purified B cells supplemented with either T cell supernatants or mitomycin C-treated T cells. Inhibiting B cell proliferation by treating them with mitomycin C before culture also abolished the generation of ISC. When ISC were enumerated after a 7-day incubation with PWM, the addition of HU as late as day 6 of culture was found to inhibit responsiveness markedly. This suggested that those cells that had acquired the capacity to secrete lg were actively dividing, and continued division was necessary for ongoing lg secretion. To examine this possibility, experiments were carried out in which responsiveness was assayed on a daily basis. ISC could be detected after a 3- or 4-day incubation and reached maximum at day 6 or 7. Addition of HU on days 3 to 7 caused a highly significant reduction in the number of ISC within 24 hr. ISC did not begin to show resistance to the effects of HU until later in culture. This observation supported the conclusions that ISC were a rapidly cycling cell population and that ongoing lg secretion, as well as expansion in the number of ISC, depended on continued proliferation of the ISC. To confirm directly that ISC were a cycling cell population, PBM were cultured with PWM for 6 days, fixed, stained for both cytoplasmic lg and DNA content, and analyzed on the fluorescence-activated cell sorter. This method made it possible to quantitate the DNA content of individual lg-synthesizing cells and thus to determine their position in the cell cycle. As many as 40% of cytoplasmic lg-positive cells were found to be in the S, G2, or M phases of the cell cycle. These data indicate that ISC generated in man after in vitro stimulation with a number of polyclonal activators are not stable terminally differentiated lg-secreting plasma cells but rather an actively cycling lg-secreting population. Furthermore, the results indicate that proliferation of the ISC themselves plays an important role in determining the magnitude of the resultant antibody response.
The mixed epidermal cell-lymphocyte reaction. I. Human epidermal cells elicit a greater allogeneic lymphocyte response than do autologous peripheral blood lymphoid cells.
Authors: Sontheimer R D
Published: December 2022

In contrast to studies by other investigators, it was observed that epidermal cells isolated from flexor forearm skin of normal adult human volunteers are consistently superior to autologous peripheral blood mononuclear cells in triggering allogeneic lymphocytes to undergo blastogeneic transformation. Stimulator cell dilution studies revealed an eightfold greater allogeneic lymphocyte-stimulating potency for epidermal cells when compared to autologous peripheral blood mononuclear cells. This difference was shown not to have resulted from enzyme exposure during cell isolation procedures or suppressor cells present in the stimulator peripheral blood mononuclear cell populations. Our technique for isolating epidermal cells is straightforward and is harmless enough to make it reasonable to consider using the mixed epidermal cell lymphocyte reaction in matching human allograft donors and recipients.
Effect of Bordetella pertussis leukocytosis (lymphocytosis)-promoting factor (LPF) on the physical lymphoepithelial-cell association studied with the use of an in vitro model of mouse thymus.
Authors: Sugimoto M , Nakanishi Y , Otokawa M , Uchida N , Yasuda T , Sato H , Sato Y
Published: December 2022

The effect of highly purified leukocytosis (lymphocytosis)-promoting factor (LPF) of Bordetella pertussis on physical lymphocyte and reticuloepithelial (RE) cell association was studied in an in vitro thymus model. First, a simplified in vitro system to assess the lympho-RE-cell association was developed. A completely confluent layer of thymic RE cells was formed by cultivating trypsinized thymus cell suspensions from 2- to 7-day-old mice. When thymic lymphoid cells were seeded on this cell layer and cultivated overnight, a significant proportion of them were found underneath the RE cell layer. This physical lympho-RE-cell association was quantitated by counting the lymphoid cells underneath the RE cell layers. Second, the effect of LPF on this physical lympho-RE-cell association phenomenon was investigated. Addition of LPF to the culture markedly inhibited the formation of the lympho-RE-cell complex; that is, it inhibited the infiltration of lymphoid cells under the RE cell layer. LPF rendered a nearly maximal level of inhibitory effect at a dose of 0.1 ng/ml. Furthermore, LPF enhanced the liberation of lymphoid cells from preformed lympho-RE-cell complexes. On the other hand, LPF had no direct cytotoxic effect on lymphoid cells at doses below 1 microgram/ml. In order to investigate whether LPF produced the effect by acting on lymphoid cells, RE cells, or both, the following experiments were performed. When lymphoid cells were pretreated with LPF and added to normal RE cell layers, the lympho-RE-cell association was maximally inhibited above the dose of 1 ng/ml. Treatment of these LPF-treated lymphoid cells with anti-LPF antibodies failed to abrogate the effect of LPF. When RE cell layers were similarly pretreated with LPF and were cultivated with normal lymphoid cells, however, much higher doses of LPF, above 100 ng/ml, were required for maximal inhibition. Furthermore, treatment of these LPF-treated RE cells with anti-LPF antibodies abrogated the effect of LPF. Therefore, the apparent effect of LPF on RE cells was considered to be due to the carry-over by RE cells of LPF, which should directly act on lymphoid cells at extremely low doses. On the basis of these results, it was concluded that LPF acted directly on lymphoid cells without mediation of RE cells. These in vitro results appear to parallel the effects of LPF in vivo, where it induces a depletion of cells in the thymus. The model may be useful to study this phenomenon and the concomitant accumulation of blood lymphocytes.
Conversion of lipopolysaccharides to molecular aggregates with reduced subunit heterogeneity: demonstration of LPS-responsiveness in "endotoxin-unresponsive" C3H/HeJ splenocytes.
Authors: Vukajlovich S W , Morrison D C
Published: December 2022

Lipopolysaccharides (LPS) of homogeneous monomeric composition were prepared by gel filtration chromatography of detergent-dissociated LPS from the smooth strain of E. coli 055:B5. Splenocyte mitogenic activity of reassociated column fractions and fraction pools is markedly dependent upon the ratio of O-antigen polysaccharide to lipid A. The activity of the homogeneous LPS in eliciting spleen cell responses varied by approximately three orders of magnitude. One of the fraction pools rich in lipid A (which contains only a trace of O-antigen polysaccharide) induces a spleen cell proliferative response in C3H/HeJ "LPS-nonresponder" spleen cells. This mitogenic activity is not present in either unfractionated LPS or O-antigen-rich fractions. These latter findings indicate LPS macromolecular aggregates of the appropriate physicochemical structure have the capacity to elicit C3H/HeJ spleen cell proliferative responses.
C3 receptors on human lymphocyte subsets and recruitment of ADCC effector cells by C3 fragments.
Authors: Wåhlin B , Perlmann H , Perlmann P , Schreiber R D , Müller-Eberhard H J
Published: December 2022

The presence of C3 receptors on human peripheral blood lymphocytes (PBL) and on the ADCC-exhibiting subset (K cells) thereof was analyzed by rosetting with bovine erythrocytes (Eb) or chicken erythrocytes (Ec) carrying human C3b, C3bi, or C3d. The indicator cells were coated with 20,000 to 100,000 C3 fragments, obtained by C3 activation with purified proteins of the alternative pathway and trypsin treatment. ADCC was studied at the cellular level by means of a plaque assay, with complement-free or complement-carrying indicator cells as targets. Of the total lymphocytes, 12 to 14% bound EC3b; 6 to 8%, EC3bi; and approximately 2%, EC3d. Surface marker analysis indicated that approximately 75% of the C3b-binding lymphocytes in PBL were either B or null cells and approximately 60% of the C3bi-binding cells were T cells, as characterized by the monoclonal antibodies OKT3 and OKT4 or by presence of receptors for Helix pomatia hemagglutinin. Of the K cells, which constituted from 5 to 10% of the total lymphocytes, approximately 20% bound C3b; 30 to 35%, C3bi; and 7 to 8%, C3d. Here the majority of the C3b binders were null cells, and the majority of the C3bi and C3d binders were T cells. Only one-third of the C3b-binding K cells and one-fifth of the C3bi-binding K cells bound both fragments. The nature of these double binding cells is unknown. In contrast, all C3d-binding K cells bound C3bi as well. C3 fragment-carrying target cells did not induce K cell-mediated lysis in the absence of anti-target antibodies but strongly enhanced ADCC in the presence of sublytic concentrations of such antibodies. The rank order for C3 fragment-induced enhancement was C3bi greater than C3d greater than C3b. It reflected the relative proportions of effector cells binding the different fragments. Enhancement was the expression of effector cell recruitment rather than of increased cytolytic activity of individual K cells. This recruitment was selective in that C3b-carrying target cells primarily recruited effector cells of null type, binding C3b, while C3bi- or C3d-carrying targets primarily recruited C3bi and/or C3d-binding K cells of T gamma type. Thus, these experiments show directly at the effector cell level that cell-bound C3 fragments constitute important recognition structures, which strongly amplify ADCC both by recruiting the proper effector cells into the cytolytic reaction and by very significantly decreasing the antibody concentration needed for its induction.
Altered oxidative metabolism in selenium-deficient rat granulocytes.
Authors: Baker S S , Cohen H J
Published: December 2022

Rats fed a selenium-deficient diet for 12 to 15 wk became selenium-depleted, measured by the selenium content of liver and granulocytes. The activity of granulocyte glutathione peroxidase, a selenoenzyme, in deficient rats was 11% of the activity in replete rat granulocytes. When stimulated with an H2O2 generating system, the HMPS activity of the deficient granulocytes was 50% of replete; however, when stimulated with methylene blue, the HMPS activity in deficient and replete granulocytes was the same. When granulocytes were incubated with PMA or OPZ, deficient granulocytes initially had the same O-2-generating activity as replete granulocytes; however, with increasing duration of stimulation, granulocytes from deficient rats generated less O-2 than replete rats. After 20 min in an H2O2-generating system, deficient granulocytes stimulated with PMA or OPZ generated less O-2 than replete granulocytes. These results indicate that deficient granulocytes did not metabolize H2O2 as well as replete granulocytes and that H2O2 caused damage to the O2-generating system. Measurement of O-2 generation in membrane-enriched particles showed the above effects were due to inactivation of the NADPH-dependent O2-generating system. Deficient granulocytes stimulated with OPZ for 20 min had 70% less membrane O-2-generating activity than controls. In addition, when membrane-enriched particles were made from cells that had been stressed with an H2O2-generating system, NADPH-dependent O-2-generating activity in deficient granulocytes was 50% of replete. In selenium-deficient granulocytes with low GSH-Px activity, prolonged incubation with stimulants and prior incubations with an H2O2-generating system caused loss of activity of the membrane-bound, NADPH-dependent, O-2-generating system.
Regulation of cell-mediated immunity in cryptococcosis. II. Characterization of first-order T suppressor cells (Ts1) and induction of second-order suppressor cells.
Authors: Murphy J W , Mosley R L , Moorhead J W
Published: December 2022

Cryptococcosis patients frequently have high levels of cryptococcal antigen in their body fluids, and the levels of circulating antigen can generally be used to predict the patient's recovery, with high or rising antigen titers indicating a poor prognosis and low or decreasing levels a good prognosis. In a previous study, we reported on a murine model for studying the effects of cryptococcal antigen on host defense mechanisms. In that work, we demonstrated that an i.v. injection of cryptococcal antigen (CneF) into CBA/J mice, to simulate the antigenemia known to occur in human cryptococcosis, induced a population of T suppressor cells (Ts1) in the lymph nodes (LN). Upon adoptive transfer, the Ts1 cells specifically suppressed the afferent limb of the delayed-type hypersensitivity (DTH) response to cryptococcal antigen. In the present study, we show that the precursors of the Ts1 cells are sensitive to low-dose cyclophosphamide treatment and that the phenotype of the Ts1 cells is Lyt-1+, Ia+ (I-J+). LN cells from CneF-injected mice or a soluble factor derived therefrom can induce in the spleens of recipient mice a second-order suppressor cell population that suppresses the efferent limb of the DTH response. The cells that induce the second-order or efferent suppressor cells have the same phenotype as the cells that appear to suppress the afferent limb of the DTH response. The findings in this study indicate that a complex regulatory mechanism is responsible for the observed suppression of the DTH response in this infectious disease model. Furthermore, the suppressive circuit thus far defined for cryptococcal antigen is similar to the antigen-specific suppressor cell pathway outlined for certain chemically defined haptenic systems.
Monoclonal antibody against a differentiation antigen on human leukemia cells: cross-reactivity with rat leukemia and suppression of rat leukemia in vivo.
Authors: Johnson R J , Shin H S
Published: December 2022

We produced a McAb against a normal differentiation antigen on human ANLL that cross-reacts with a rat ANLL. The McAb reacted with all ANLL cells tested as well as normal undifferentiated myelomonocytic cells. This McAb, of the IgM isotype, in the presence of C mediated lysis of human and rat leukemic cells in vitro. In addition, it mediated complete tumor suppression in rats engrafted with 10(2) to 10(3) rat leukemic cells in vivo. No significant side effects were observed in McAb-treated rats. McAb of this type may be useful in the treatment of human ANLL after conventional therapy, which often eliminates most leukemic cells, leaving a small number of residual cells. The ultimate utility of this McAb for human therapy or McAb directed against the same or other differentiation antigens remains to be determined.
Studies on the mechanism of natural killer cell-mediated cytotoxicity. IV. Interferon-induced inhibition of NK target cell susceptibility to lysis is due to a defect in their ability to stimulate release of natural killer cytotoxic factors (NKCF).
Authors: Wright S C , Bonavida B
Published: December 2022

The effects of interferon (IFN) at the level of the target cell in the natural killer cytotoxic factors (NKCF) system have been examined to determine whether they correlate with the effects of IFN in natural killer (NK) cell-mediated cytotoxicity (CMC). NKCF are released into the supernatant of co-cultures of murine spleen cells and YAC-1 stimulator cells, and their lytic activity is measured against YAC-1 target cells. It was found that IFN-pretreated YAC-1 target cells were still sensitive to lysis by NKCF, although their ability to stimulate release of NKCF from murine spleen cells was impaired. This defect was not due to a lack of NK target structures, because IFN-pretreated YAC-1 cells form a normal number of conjugates with spleen cells. The defect also could not be attributed to an IFN-induced inhibition of protein synthesis, because emetine-pretreated YAC-1 stimulator cells can still induce the release of high levels of NKCF. Cellfree supernatants containing NKCF also contain low levels of endogenous IFN (10 to 50 U/ml). Although this concentration of IFN itself is not toxic to YAC-1 cells, it may still interact with NKCF and/or the target cell to enhance cytotoxicity mediated by NKCF. Evidence in support of this possibility is derived from experiments that demonstrated that addition of exogenous IFN to NKCF resulted in a synergistic enhancement of cytotoxicity. Taken together, these findings can account for the IFN-induced inhibition of target cell susceptibility to lysis in the NK CMC system. In addition, the evidence supports our model for the role of NKCF in the mechanism of NK CMC. According to this model, the effector cell must first bind to the target cell; then the target cell delivers a signal to the effector cell to activate the NKCF release mechanism. The effector cell releases NKCF that then bind to the target cell and mediate cell lysis. The mechanism by which IFN-pretreated target cells become relatively NK-resistant appears to be a defect in their ability to stimulate the effector cell to release NKCF after the initial effector-target cell binding.
Immune capacity of the chicken bursectomized at 60 hours of incubation: mitogen-induced cell proliferation and immunoglobulin secretion.
Authors: Eerola E , Jalkanen S , Granfors K , Toivanen A
Published: December 2022

Chickens were bursectomized surgically at 60 hr of incubation. Bone marrow cells from the bursectomized (Bx) and control (Co) chickens responded equally well by proliferation to B cell mitogens (dextran sulfate, anti-mu, anti-gamma) when studied at the age of 10 weeks. In contrast, spleen cells of Bx chickens responded significantly less to anti-mu and anti-gamma than did spleen cells of the Co chickens. When observed at the age of 10 days, a significantly depressed secretion of IgM, IgG, and IgA by the Bx cells was observed in vitro. This difference between the Bx and Co chickens had disappeared when studied at the age of 10 weeks.
Blockade of Fc receptor-mediated binding to U-937 cells by murine monoclonal antibodies directed against a variety of surface antigens.
Authors: Kurlander R J
Published: December 2022

The effect of murine IgG hybridoma antibodies directed against leukocyte antigens on the Fc receptor function of human cells was studied. For this purpose, the specific binding of 125I-labeled monomeric human IgG1 to a macrophage-like cell-line (U-937) was quantitated before and after incubation in the presence of murine monoclonal hybridoma antibodies. Four monoclonal hybridoma antibodies (A1G3, 23D6, 4F2, and 3A 10), each of which binds to different antigens on the surface of U-937 cells, rapidly and potently inhibited the specific binding of labeled IgG1 to these cells. Inasmuch as inhibition was mediated only by IgG antibodies with an intact Fc fragment and antibody activity against surface antigens found on U-937, inhibition appears to have resulted from the formation of a three-component complex composed of antibody bound by its Fab portion to antigen and by its Fc fragment to a Fc receptor. Equilibrium binding studies performed on treated cells confirmed that reduced Fc receptor-mediated binding was due to a reduction in the number of available receptors. Binding studies employing double isotope labeling methods demonstrated that about 0.5 to 1.0 Fc receptor was blocked for each molecule of intact antibody bound to a U-937 cell. Using several techniques, it was shown that most of the monoclonal antibody bound to cells and the Fc receptors blocked by antibody remained on the cell surface despite incubation at 37 degrees C for 3 hr. Thus, the loss of receptor function observed in these experiments was almost exclusively due to reversible receptor blockade rather than receptor internalization or degradation. The antibodies identified in these studies also markedly inhibited Fc receptors on one other human cell line (HL-60) as well as those on normal human peripheral blood monocytes.
Identification and functional characterization of two distinct epitopes on the human T cell surface protein Tp50.
Authors: Martin P J , Longton G , Ledbetter J A , Newman W , Braun M P , Beatty P G , Hansen J A
Published: December 2022

The structural and functional domains of Tp50, the human T lymphocyte surface protein associated with the E rosette receptor, were probed with the use of two murine monoclonal antibodies. Lysostripping, immune precipitation, and competitive binding experiments demonstrated that antibodies 9.6 and 35.1 bind to Tp50 epitopes in close proximity. In functional studies, both antibodies caused a similar degree of antigenic modulation, inhibited T cell proliferative responses, and inhibited cytotoxic T lymphocyte function without affecting cells that mediate antibody-dependent cell-mediated cytotoxicity. The antibodies were strikingly different, however, in that antibody 9.6 inhibited E rosette formation and natural killer cell-mediated lysis, whereas antibody 35.1 did not. These results could not be ascribed to differences in antibody class or binding characteristics, because Scatchard analysis demonstrated that these two IgG2a antibodies have comparable avidity and that T cells bind each antibody in equivalent amounts. The differential binding of antibodies 9.6 and 35.1 to T cells from nonhuman primates further supports the interpretation that the differences between the antibodies in their effects on E rosette formation and natural killer function stem from the fact that they bind to distinct epitopes of Tp50. The implications of these findings for understanding the functions of Tp50 molecules are discussed.
Con A-induced TCGF-reactivity is selectively acquired by Lyt-2-positive T cell precursors.
Authors: Gullberg M , Larsson E L
Published: December 2022

We investigated whether concanavalin A-stimulated, TCGF-reactive, and TCGF-producing T cells could be separated with regard to their Lyt phenotypes. Normal spleen cells, pretreated with monoclonal anti-Lyt-1 or anti-Lyt-2 antibodies and complement were assayed for their capacity to respond to TCGF, as well as for their ability to produce TCGF after Con A stimulation. The results demonstrate that reactivity to TCGF is predominantly induced in Lyt-2+ lymphocytes, because it is reduced by more than 95% in Lyt-1+23- T cell populations as compared with cultures containing Lyt-1-23+ cells. Limiting dilution analysis revealed that up to 20% of the cells in Lyt-2-containing populations were induced by Con A to TCGF-reactivity, whereas 20-fold fewer clones were induced in the Lyt-2-depleted cell populations. On the other hand, the study of TCGF production in Lyt-1-23+ populations revealed that the former population was considerably enriched in TCGF-producing T cells, whereas the latter was substantially depleted. We conclude that TCGF-producing and TCGF-reactive T cells are largely distinct lymphocyte populations that can be separated on the basis of their Lyt phenotypes.
B4, a human B lymphocyte-associated antigen expressed on normal, mitogen-activated, and malignant B lymphocytes.
Authors: Nadler L M , Anderson K C , Marti G , Bates M , Park E , Daley J F , Schlossman S F
Published: December 2022

The characterization of a new B cell-specific antigen (B4) is described in this report. With the use of a monoclonal antibody to B4, it was shown that B4 is present on B cells isolated from peripheral blood and lymphoid organs, on cell lines derived from normal and malignant B cells, and on tumor cells isolated from patients with B cell-derived neoplasms. B4, in contrast, was not detected on normal, activated, or malignant cells of T or myeloid origin. The B4 antigen is distinct from known B cell antigens, including sIg, Ia, B1, B2, Fc, and C3. Examination of mitogen-stimulated B lymphocytes suggests that the B4 antigen initially increases with B cell activation and then is lost at the terminal stage of B cell differentiation. Moreover, the observation that B4 is expressed on almost all early B cell tumors suggests that it may precede B1, CALLA, cytoplasmic mu, and B2 in early B cell ontogeny.
In vivo and in vitro production of anti-histone antibodies in NZB/NZW mice.
Authors: Gioud M , Kotzin B L , Rubin R L , Joslin F G , Tan E M
Published: December 2022

Anti-histone antibodies have been demonstrated in the sera of patients with both idiopathic and drug-induced lupus. We measured anti-histone antibodies in female NZB/NZW (F1) mice, which are considered to be a model of human SLE. Using a sensitive and quantitative enzyme-linked immunosorbent assay (ELISA), we detected minimal serum antibody activity in NZB/NZW mice younger than 4 mo of age and in nonautoimmune mice at all ages tested. Serum anti-histone antibodies progressively increased in NZB/NZW mice from 4 to 8 mo of age and showed an age-related maturation from IgM to IgG. The predominant antibody activity in the older mice was to the individual histones H2B and H3, and the pattern of reactivity to the histone proteins was similar to that seen in human SLE. We also studied the spontaneous in vitro production of anti-histone antibodies using spleen cells from NZB/NZW mice of different ages. Culture supernatants were analyzed for antibody activity by an ELISA with total histones as the antigen. Spleen cells from older NZB/NZW mice, with elevated serum levels, produced 10-fold higher levels of antibody activity compared to age-matched nonautoimmune mice. Antibody production was maximal at 4 days of culture and was inhibited by the addition of puromycin to the culture. Surprisingly, spleen cells from 1 to 3-mo-old NZB/NZW mice, with normal serum levels, also demonstrated significantly elevated production. The antibodies produced by these young mice were mostly IgM, whereas spleen cells from older mice produced mostly IgG anti-histone antibodies. The present results provide the basis for using the anti-histone antibody system to study further the immune abnormalities that allow for autoantibody production.
Induction of Ia and H-2 antigens on a macrophage cell line by immune interferon.
Authors: King D P , Jones P P
Published: December 2022

Recent work from a number of laboratories has suggested that Ia antigen expression on macrophages can be modulated by soluble factors released by T cells after antigen or mitogen activation. The murine macrophage tumor cell line, WEHI-3, provides an in vitro system for the study of this type of lymphokine regulation of Ia antigen expression. Previous work from our laboratory has shown that supernates from Concanavalin A-activated rat or mouse spleen cells (Con A sup) can stimulate increased levels of biosynthesis and cell surface expression of both Ia and H-2K,D antigens on this cell line. The experiments described in this report were designed to identify the regulatory factor responsible for this inducing activity, and in particular to determine whether the inducing factor present in crude supernatant fluids is immune interferon (IFN-gamma). These experiments show that: 1) murine IFN-gamma, produced free of other lymphokines by recombinant DNA technology and DNA-mediated gene transfer, can induce Ia antigen expression and increase H-2 antigen expression on WEHI-3 cells; 2) the biochemical characteristics of partially purified inducing factor from crude supernate fluids are similar to those previously described for murine IFN-gamma by other investigators; and 3) both crude Con A sup and IFN-gamma-containing supernates have inducing activity and antiviral activity which exhibit very similar dose-related responses. These results support the conclusion that the previously described ability of Con A sup to regulate MHC antigen expression on WEHI-3 cells is due to the activity of immune interferon in those supernates.
Characterization of a novel differentiation antigen complex recognize by a monoclonal antibody (A-1A5): unique activation-specific molecular forms on stimulated T cells.
Authors: Hemler M E , Ware C F , Strominger J L
Published: December 2022

By using a single monoclonal antibody, a novel glycoprotein complex composed of at least three distinct bands was defined on the surface of mitogen- or alloantigen-stimulated T cells. These bands (210,000, 165,000, and 130,000 Mr) were not disulfide linked and could be radio-labeled with 125I or 35S-methionine and readily detected by immunoprecipitation with the monoclonal antibody A-1A5. Only approximately 20% of normal T cells (E rosette positive) and approximately 47% non-T cells (E rosette negative) were reactive with A-1A5. However, upon activation of T cells, the amount of A-1A5 binding per cell and the percentage of positive cells significantly increased. This increase was most pronounced in the activated cell subpopulations currently undergoing cell division (S, G2, and M phases), which became 79% A-1A5 positive (after PHA stimulation) and 99% A-1A5 positive (in long-term culture with alloantigen and IL2). Resting lymphocytes contained only the 130,000 Mr band reactive with A-1A5. The two other bands (210,000 and 165,000 Mr) were markers for T cell activation and only appeared several days after T cell stimulation and became especially prominent after the addition of exogenous IL 2. All T lymphoblastoid cell lines tested expressed at least the lower bands (130,000 Mr), and the T cell line HSB also expressed one of the activation-related larger proteins (165,000 Mr). B lymphoblastoid cell lines expressed only a very weak lower band (130,000 Mr), and the cell line U-937 (in the monocyte-macrophage lineage) expressed only a single band (145,000 Mr) not aligned with any of the bands found on lymphoid cells. The estimated number of A-1A5 binding sites per cell was much higher on U-937 (11 X 10(5)), and generally higher on other cell lines of myeloid lineage (1 to 4 X 10(5)) than on lymphoid cell lines (0.2 to 1.3 X 10(5)).
Binding of phosphorylcholine by non-immunoglobulin molecules on mouse B cells.
Authors: Bach M A , Kohler H , Levitt D
Published: December 2022

Phosphorylcholine (PC), a molecule found in the cell wall of most serotypes of pneumococcus, has been used extensively as a probe for the study of network interactions during immune responses. The frequency of B lymphocytes capable of interacting with PC has not been directly examined. We used immunofluorescence to study the binding of PC and monoclonal anti-TEPC15 anti-idiotopic antibodies to murine lymphocytes. In addition to identifying PC-specific Ig molecules, PC was bound by a non-Ig molecule on the surface of a relatively large subset of B cells; this non-Ig marker shared an idiotypic determinant with the PC-binding myeloma protein HOPC8 (H8). PC-bearing R36a pneumococci bind to a similar subset of lymphocytes. This binding is inhibited specifically by PC coupled to bovine serum albumin and also by a monoclonal anti-H8 antibody. We suggest that bacterial interaction with B cells through non-Ig molecules capable of binding a dominant antigen like PC may possess functional significance, possibly during the events that lead to antibody induction by these microorganisms.
Surface modulation of classical pathway activation: C2 and C3 convertase formation and regulation on sheep, guinea pig, and human erythrocytes.
Authors: Brown E J , Ramsey J , Hammer C H , Frank M M
Published: December 2022

We examined the formation of the early classical complement (C) pathway enzymes on sheep (Es), guinea pig (Egp), and human (Eh) erythrocytes (E). Each species' E were sensitized with sufficient IgM or IgG anti-E Ab to establish equal numbers of C1-fixing sites on all E. After sensitization with 100 C1-fixing sites of Ab and excess C1, uptake of C4 was equivalent on all three cell types, judged by anti-C4 binding (for guinea pig C4) or by direct uptake of radiolabeled protein (for human C4). With equal numbers of cell-bound C1 and C4, however, there were marked differences in C2 convertase activity on Es, Egp, and Eh. Sheep EAC14 utilized C2 at least 20 times faster than Egp and Eh bearing the same number of C1 and C4 molecules. C3 cleavage was even further depressed on Egp and Eh, and was not changed by the substitution of oxyC2 for normal human C2. In whole guinea pig serum (GPS), 300 times more C1-fixing sites were required on Egp than on Es to achieve similar amounts of lysis; however, equivalent C3 uptake on Egp and Es was associated with equal extents of lysis, demonstrating that GPS lysis of these cells was regulated by early steps in classical pathway (CP) activation. Incubation of E bearing radiolabeled C4b with Factor I demonstrated that C4b on Egp was highly resistant to cleavage compared to the same protein bound to Es or Eh. Studies with partially purified C3 convertase decay-accelerating factors from Eh stroma demonstrated that these membrane proteins could not account for the observed surface regulation of CP activity because these proteins do not affect the rate of C2 cleavage by EAC14. We conclude that E surface molecules have an important role in modulation of CP activation. This surface-associated CP regulation occurs at the level of cell-bound C4b.
Enhancement of eosinophil effector function by soluble factors released by S. mansoni: role of proteases.
Authors: Auriault C , Capron M , Cesari I M , Capron A
Published: December 2022

Schistosomulum-released products (SRP) have been shown to enhance both expression of rat and human eosinophil Fc receptors and IgG-dependent cytotoxicity. The present work provides additional evidence of the secretion of eosinophil-enhancing factors by schistosomula and other developmental stages of schistosomes, including adult worms. The heat lability, as well as the strong inhibition of the stimulating activity of SRP by the protease inhibitor Trasylol, suggest that thermolabile proteases secreted by the parasite are involved in this mechanism. The purification of the schistosome proteases by preparative isoelectric focusing and gel filtration demonstrated that neutral proteases able to hydrolyze the collagenase substrates Azocoll and Z-Gly-Pro-Leu-Gly-Pro are able to significantly enhance eosinophil effector functions. Purified Clostridium histolyticum collagenase was also able to mimic the enhancing effect of schistosome proteases, suggesting involvement of a collagenase-like activity of the enzymes in the eosinophil stimulation.
Cross-reactivity patterns of influenza-specific cytotoxic T lymphocytes from H-2Kb mutant mice.
Authors: Hurwitz J L , Wettstein P J , Bennink J R , Doherty P C
Published: December 2022

Limit dilution cultures were used to test for influenza immune T cell populations from bm1 and bm3 mutant mice that were not lytic for virus-infected targets expressing the Kb and Db major histocompatibility complex glycoproteins. Both Kbm3- and Kbm1-restricted cytotoxic T cells were detected. Such effectors showed minimal cross-recognition of influenza on other mutant targets, except for the case of bm1 and bm10 targets. This is dissimilar to previous findings concerning vaccinia presentation in which bm3+bm11, bm1+bm9, and bm3+bm9 pairs each showed high cross-reactivity. These differences illustrate the role of the H-2K glycoprotein in immune responsiveness. Not only are multiple determinants on each H-2K glycoprotein involved in antigen presentation, they appear to play differential roles in the presentation of different viral antigens.
Genetic control of scrapie and Creutzfeldt-Jakob disease in mice.
Authors: Kingsbury D T , Kasper K C , Stites D P , Watson J D , Hogan R N , Prusiner S B
Published: December 2022

Genetic control of experimental scrapie and Creutzfeldt-Jakob disease (CJD) was studied in inbred strains of mice by measuring the times from intracerebral inoculation with the agents to the onset of neurological dysfunction. Every strain of mice examined was susceptible to infection; however, a wide range of incubation times was found for both scrapie and CJD. New Zealand (NZ) mice, which eventually develop an autoimmune disorder, were inoculated intracerebrally with 10(6) ID50 units of the scrapie agent in a Chandler isolate. NZW mice showed incubation periods of less than 95 days; this is the shortest period recorded for any murine host with scrapie. In NZB and NZB X W F1 mice, the incubation periods were approximately 130 days and were similar to those in BALB/c and C57BL mice. Male and female NZ mice exhibited scrapie incubation periods of the same length. Similar results were obtained when B10.Q and C57BL/6J mice were inoculated intracerebrally with 10(4) ID50 units of the CJD agent in a K.Fu. isolate. These observations define a genetic locus or loci controlling the length of scrapie and CJD incubation periods; alleles coding for longer incubation times appear to be autosomal dominant. When congenic mice with a C57BL/10J background differing only in their H-2 haplotypes were studied, the results showed that the D subregion of the H-2 complex played a central role in controlling the length of the CJD incubation period. The q allele at the D subregion resulted in shorter incubation times, whereas the d allele resulted in long incubation times. The p, s, b, and k alleles gave intermediate incubation times. We propose the symbol PID-1 for designating this genetic locus which is located within the D subregion of the major histocompatibility (H-2) complex on murine chromosome 17. In addition, observations on congenic mice provide evidence for the influence of sex on CJD incubation periods. In some strains of inbred mice, males showed significantly shorter incubation periods compared with those for females with experimental CJD. These studies with inbred mice have defined previously unrecognized genes that control the length of scrapie and CJD incubation periods.
Modulation of the IgG subclass responses to lipopolysaccharide by bacterial membrane components: differential adjuvant effects produced by primary and secondary stimulation.
Authors: Karch H , Nixdorff K
Published: December 2022

The characteristic modulating effects of bacterial membrane adjuvants on the IgG subclass responses to lipopolysaccharide (LPS) were further investigated. Previous studies indicated that more hydrophobic adjuvants preferentially augmented the number of LPS-specific IgG1 plaque-forming cells (PFC) whereas more hydrophilic adjuvants induced predominantly IgG2 PFC, and that complex formation between LPS and adjuvants was necessary for this modulation. In the present report, no carrier effect of adjuvants in the classic immunologic sense could be detected. Undiminished secondary IgG responses to LPS were obtained regardless of which adjuvant was used for the secondary injection. When IgG subclass responses were examined, however, differential effects of adjuvants produced by primary and secondary injections were observed. The adjuvant used in combination with LPS for the primary stimulus determined the number and subclass of LPS-specific IgG memory cells induced: The same or a different adjuvant used with LPS for the secondary stimulus effected the induction of these memory cells to antibody-producing cells. The pattern set by the primary stimulus was not altered by the secondary stimulus, regardless of the potential modulating effect of the second adjuvant.
Characteristics of thymus-homing bone marrow cells.
Authors: Lepault F , Coffman R L , Weissman I L
Published: December 2022

Using a short-term in vivo assay, we studied bone marrow cells capable of homing to the thymus of lethally irradiated recipients. In the bone marrow, these cells lack the T cell markers Thy-1 and Lyt. Soon after their homing into the thymus, however, the immigrants begin to express Thy-1 and Lyt antigens, but not TL antigen. Unexpectedly, Lyt antigens appear to be expressed before Thy-1. These thymus-homing bone marrow cells seem to be already separated from the B cell lineage. Most of the homing cells are engaged in the cell cycle.
The delayed-type hypersensitivity response to (4-hydroxy-3-nitrophenyl) acetyl- (NP) coupled proteins is carrier-specific: in vivo and in vitro demonstrations.
Authors: Barry W C , Ruddle N H
Published: December 2022

In vivo and in vitro approaches for measuring DTH to NP and the cross-reactive hapten, NIP, were taken. Mice were immunized subcutaneously with NP-OVA, NP-BGG or NP-CGG in CFA or NP-spleen cells, challenged intradermally with NP or NIP-coupled to a heterologous carrier, and footpad or ear swelling determined 4, 24, and 48 h later. Alternatively, draining LNC were removed and challenged in vitro with either haptenated protein or haptenated, irradiated, syngeneic spleen cells to induce lymphotoxin (LT) production or proliferation. Our results show that although carrier-specific DTH responses are easily elicited both in vivo and in vitro, NP-specific DTH effector cells cannot be evoked by conventional immunization regimens. This failure to induce hapten-specific DTH is not due to suppressor mechanisms. Attempts to induce LT production and T cell proliferation by re-exposure to NP were unsuccessful. Immunization with NP-coupled protein in CFA does elicit an intense Arthus reaction when mice are challenged with the hapten 8 days later. The antibody-mediated nature of this hapten-specific response is indicated by the kinetics of the reaction, which peaks 4 hr after challenge, intensely positive ELISA of circulating anti-NP antibodies, sensitivity to pretreatment with a high dose of cyclophosphamide, and the ability to transfer the reaction to naive recipients with serum. This early response is highly cross-reactive with NIP and is not restricted to mice of the igh-1b allotype.
Analyses of the splenic mRNA expressed by rabbits of different immunoglobulin kappa-light chain allotypes: conserved sequences in the 3' untranslated region and allotype-specific probes.
Authors: Pavirani A , McCartney-Francis N , Jacobsen F , Mage R G , Reddy E P , Fitzmaurice L C
Published: December 2022

The allelism of the structural genes for the complex rabbit b allotypes of immunoglobulin kappa-light chains has been questioned because of observations of unexpected phenotypic expression of "latent" allotypes. We find that the coding sequences of the b4 and b5 "alleles" are only 80% homologous for the last 60 nucleotides but there is a high degree of homology (96%) in the 3' untranslated region (3'DT). The high conservation of 3' DT region sequences enabled us to detect kappa-light chain mRNAs from rabbits of different genetic types (b4, b5, b9 and bbas) on northern blots and dot blots. We can distinguish mRNA encoding b9 and b5 allotypes on dot blots with b5 fragment-probes of known sequence and detect mRNA produced by unstimulated cultured splenic lymphocytes. Analyses of mRNA from cultured cells manipulated to enhance mRNA synthesis and production of unexpected or "latent" b allotypes can now be conducted.
The functional significance, distribution, and structure of LFA-1, LFA-2, and LFA-3: cell surface antigens associated with CTL-target interactions.
Authors: Krensky A M , Sanchez-Madrid F , Robbins E , Nagy J A , Springer T A , Burakoff S J
Published: December 2022

Three cell surface antigens associated with the cytolytic T lymphocyte(CTL)-target cell interaction were identified by generation of monoclonal antibodies (MAb) against OKT4+, HLA-DR-specific CTL and selection for inhibition of cytolysis in a 51Cr-release assay. These MAb block cytolysis by both OKT4+ and OKT8+ CTL and the proliferative responses to PHA and the mixed lymphocyte response (MLR). LFA-1 is an antigen widely distributed on lymphoid tissues and is composed of two polypeptides of 177,000 and 95,000 Mr on all cell types studied. Anti-LFA-1 MAb block NK cell-mediated cytolysis in addition to T lymphocyte-mediated cytotoxicity and proliferation. LFA-2 (Mr = 55,000 to 47,000), a determinant on the sheep red blood cell receptor, is expressed by T cells but not B cells and appears specific for T cell functions. LFA-3 (Mr = 60,000) is a widely distributed antigen present on both hematopoietic and nonhematopoietic tissues and appears to only be involved in T cell functions. MAb to LFA-1 and LFA-2 inhibit function by binding to effector cell surface molecules, whereas anti-LFA-3 MAb appear to block by binding to the target cells. Together with previously described molecules, LFA-1, LFA-2, and LFA-3 demonstrate the complexity of CTL-mediated cytotoxicity at the molecular level.
In vitro activity and in vivo correlates of alloantigen-specific murine suppressor T cells induced by allogeneic pregnancy.
Authors: Nagarkatti P S , Clark D A
Published: December 2022

The fetus that results from allogeneic mating in an outbred population bears a variety of antigens against which the maternal immune system reacts, but the type of immunity that is elicited by pregnancy does not mediate graft rejection. Previous studies have demonstrated the presence of nonspecific non-thymus derived suppressor cells in the lymph nodes draining the uterus (DLN) and in the uterine decidua during first allogeneic pregnancy. These suppressor cells appear to be small lymphoid cells that inhibit the generation of cytotoxic T cells (CTL) against paternal alloantigens. We now report that after a single allogeneic pregnancy, C3H and A strain mice develop paternal alloantigen-specific suppressor T cells (Thy-1.2+, Lyt-1-2+) that are distributed systemically in peripheral lymph nodes and spleen. These suppressor cells appear to act directly on CTL generation because the frequency of CTL precursors and the ability to produce T helper cells in response to paternal alloantigens remains unchanged after allogeneic pregnancy. Suppressor T cell activity could be detected both in vitro and in vivo, and the presence of suppression in vivo was associated with increased uterine weight 5 days after inoculation of allogeneic paternal tumor cells into the uterus of pseudopregnant mice. Nevertheless, both subcutaneous and intrauterine tumor inocula regressed in these mice with suppressor T cells. The possible role of suppressor T cells in contrast to non-T suppressor cells in successful reproduction and allopregnancy-induced tolerance is discussed.