bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of lipopolysaccharide-high density lipoprotein binding by acute phase protein(s).
Authors: Tobias P S , Ulevitch R J
Published: December 2022

When Salmonella minnesota R595 lipopolysaccharide (LPS) is mixed with serum, the LPS eventually forms a complex with high density lipoprotein (HDL). Complex formation is conveniently followed by CsCl equilibrium density gradient centrifugation. When mixing 10 micrograms LPS with normal rabbit serum (NRS) at 37 degrees C in the presence of 20 mM EDTA, the half-life for LPS binding to HDL is typically 2 to 3 min. When the same experiment is performed with the use of acute phase rabbit serum (APRS; collected 24 hr post-induction with silver nitrate), the half-life for LPS binding to HDL is typically 40 to 100 min. Thus LPS binding to HDL occurs some 20- to 40-fold slower in APRS than in NRS. Two other phenomena have been found, the time dependencies of which correlate well with the time dependency of LPS binding to HDL in APRS. If LPS-APRS reaction mixtures are cooled to 4 degrees C shortly after mixing and are dialyzed against 2.5 mM HEPES, 15 mM NaCl, pH 7.4 buffer, LPS is recovered in the washed precipitates ("euglobulin precipitate") if, and only if, the LPS-HDL binding reaction is not complete. The amount of LPS in the precipitate correlates well with the amount of LPS that has not bound to HDL. The second phenomenon we observe is that the LPS-containing euglobulin precipitate prepared from LPS-acute phase serum reaction mixtures shortly after mixing also contains a protein, gp60, the concentration of which in the euglobulin precipitate correlates well with the amount of LPS in the precipitate. Thus three phenomena are kinetically well correlated in APRS: the degree of binding of LPS to HDL, the degree of appearance of LPS in a euglobulin fraction, and the concentration of protein gp60 in the euglobulin fraction. We were unable to precipitate gp60 from APRS in the absence of LPS, from APRS after the LPS has fully bound to HDL, or from normal serum in the presence or absence of LPS. The known properties of gp60 are not reminiscent of any other known acute phase reactant. These data demonstrate that APRS contains acute phase reactants that interact with LPS to modify its buoyant density, its solubility, and the rate of its binding to HDL.
C3b deposition during activation of the alternative complement pathway and the effect of deposition on the activating surface.
Authors: Pangburn M K , Schreiber R D , Müller-Eberhard H J
Published: December 2022

Examination of C3b deposition on the surface of activators during alternative pathway activation revealed three temporal phases: a lag phase, an amplification phase, and a heretofore uncharacterized plateau phase. During the plateau phase no C3b deposition appeared to occur even in the presence of an excess of alternative pathway components. Double label experiments, however, revealed that the plateau was a steady state between continued C3b deposition and release of C3b or C3bi from the activator. Under conditions of excess complement it was found that deposition of increasing numbers of C3b molecules caused a gradual increase in the ability of Factors H and I to inactivate newly deposited C3b; i.e., the deposited C3b converted the activator into a nonactivator. The data indicate that the surface of rabbit erythrocytes is rendered completely nonactivating when 2.4 X 10(6) molecules of C3b plus C3bi are bound per cell. The plateau of C3b deposition appears to represent the maximum steady state level maintainable by a given concentration of complement components, and it also reflects conversion of an activating surface to one resembling a nonactivator.
Cellular mechanisms of genetically controlled host resistance to Mycobacterium bovis (BCG).
Authors: Gros P , Skamene E , Forget A
Published: December 2022

Multiplication of Mycobacterium bovis (BCG) in the reticuloendothelial tissues of the mouse is controlled by the Chromosome 1 locus (Bcg), which exists in two allelic forms, resistant (Bcgr) and susceptible (Bcgs). We have investigated the phenotypic expression of this locus at the cellular level in vivo. No significant differences were observed in the early clearance of BCG from the bloodstream and peritoneal cavity, nor in the uptake of the infectious inoculum in spleen and liver of the mice of Bcgr and Bcgs strains. Inflammatory response to an i.p. injection of live BCG, with respect to both the cell populations involved and the kinetics of their appearance, was comparable in Bcgr and Bcgs mice. A kinetic study of BCG infection in congenitally athymic mice that carried the "nude" mutation on Bcgr (AKR/J) or Bcgs (BALB/c) background showed that the functional absence of T lymphocytes did not influence the expression of the Bcg gene. The population expressing the Bcg gene seems to be a mature cell of the mononuclear phagocyte lineage: it was resistant to a 950-rad dose of x-irradiation; it was susceptible to a prolonged exposure to silica; and, as demonstrated in radiation chimeras, it originated from bone marrow-derived precursors.
Humoral immune response in experimental syphilis to polypeptides of Treponema pallidum.
Authors: Hanff P A , Bishop N H , Miller J N , Lovett M A
Published: December 2022

The ontogeny of the IgG response in rabbits with experimental syphilis to individual polypeptides of Treponema pallidum, Nichols strain, was examined. The polypeptides of motile, virulent T. pallidum, purified from host tissue by Percoll density gradient centrifugation, were separated on SDS-polyacrylamide gels and were electrophoretically transferred to a solid-phase matrix of nitrocellulose for antigen analysis. Serum from rabbits early in infection at day 3 post-infection showed a weak but detectable IgG response to two polypeptides of 60,000 and 46,000 m.w. This was followed on days 11, 17, and 19 by an apparent quantitative increase in antibody to other treponemal protein antigens. By day 19, 21 of the 22 detectable polypeptides could be identified. A similar set of antigens was detected by serum from patients with human secondary and early latent syphilis. A close correlation was found between the presence of IgG antibody to T. pallidum polypeptides at day 9 and 1, 4.5, 13.5, and 17 mo post-infection and the immune status of the rabbit to symptomatic reinfection. Serum from rabbits that were partially immune to challenge at day 9 detected three polypeptides of 60,000, 46,000, and 36,000 daltons. By 1 mo post-infection, at a time when a more complete immunity had developed, the number of detectable antigens increased to 21 polypeptides ranging in m.w. from 94,000 to 14,400 daltons. IgG antibody to 22 treponemal antigens persisted in animals that were solidly immune to symptomatic reinfection at 3, 4.5, 13.5, and 17 mo post-infection. Serum neutralizing activity was not demonstrable at day 9 or 1 mo post-infection, however, but was present at 3, 4.5, 13.5, and 17 mo. The results suggest that after intratesticular challenge a vigorous IgG response to T. pallidum polypeptides can be detected. The potential role of humoral immune mechanisms in the development and maintenance of immunity is discussed.
The mechanism of retrovirus suppression of human T cell proliferation in vitro.
Authors: Copelan E A , Rinehart J J , Lewis M , Mathes L , Olsen R , Sagone A
Published: December 2022

Immunosuppression is commonly associated with retrovirus-induced animal tumors. Studies in the murine and feline retrovirus systems suggest that the 15,000-dalton envelope protein (p15E) of the virion may contribute to immunosuppression by interfering with normal lymphocyte function. We examined the effect of inactivated feline leukemia virus (UV-FeLV) and p15E derived from this virus on concanavalin A (Con A) driven human T cell proliferation. Virus and p15E markedly suppressed mononuclear cell proliferative response to Con A. Suppression was not due to inhibition of monocyte accessory cell function, or interleukin 1 (IL 1) secretion. In fact, the presence of monocytes partially protected T cells from UV-FeLV suppression. UV-FeLV, however, suppressed T cell secretion of and response to interleukin 2 (IL 2). We conclude that UV-FeLV and derived p15E inhibit T cell proliferation by direct inhibition of T cell function. These findings, extended to the in vivo situations, suggest that retrovirus-associated suppression of the immune response involves the induction of T cell but not monocyte dysfunction.
The binding of tumor cells by murine mononuclear phagocytes can be divided into two qualitatively distinct types.
Authors: Somers S D , Mastin J P , Adams D O
Published: December 2022

Peritoneal macrophages from C57BL/6N mice infected with BCG have a greater capacity for tumor cell binding than do inflammatory macrophages elicited by several agents. To determine if these quantitatively distinct types of binding were qualitatively distinct as well, we compared them in several ways. Scanning electron microscopy of macrophage-tumor cell interactions reveals clustering of 2 to 5 tumor targets on the central portion of BCG-activated macrophages, in contrast to the very few tumor cells found at the periphery of inflammatory macrophages. Tumor cell binding to BCG-activated macrophages required divalent cations and trypsin-sensitive surface structures on the macrophages, but the low-level binding to inflammatory macrophages required neither. The ability of trypsinized BCG-activated macrophages to bind P815 tumor targets was recovered with time in culture. BCG-activated macrophages required intact energy metabolism, microfilaments, and microtubules to complete augmented tumor cell binding, whereas inflammatory macrophages did not. Targets bound to BCG macrophages could be competitively removed by addition of large excesses of unlabeled tumor cells, but targets bound to inflammatory macrophages could not be so removed. Tumor cells labeled with 111Indium oxine were used to estimate the specific (i.e., competitively inhibitable) and nonspecific (noncompetitively inhibitable) components of binding. Binding of P815 tumor cells to BCG-activated macrophages was predominantly specific, whereas their binding to inflammatory macrophages was predominantly nonspecific. Binding by activated or inflammatory macrophages of lymphocytes or by transformed 3T3 cells of neoplastic or non-neoplastic targets was also nonspecific. Binding by BCG-elicited macrophages from A/J mice, previously demonstrated to be quantitatively deficient in binding ability, was qualitatively similar to that to inflammatory macrophages and was not competitively inhibitable. The data suggest that tumor cell binding by activated macrophages is qualitatively as well as quantitatively distinct from binding to inflammatory macrophages.
Lyb-5- B cells of CBA/N mice can be induced to synthesize DNA by culture with insolubilized but not soluble anti-Ig.
Authors: Mond J J , Schaefer M , Smith J , Finkelman F D
Published: December 2022

The use of anti-immunoglobulin (anti-Ig) antibodies to stimulate B cell proliferation (1-4), and to stimulate B cell differentiation in the presence of T cell derived-lymphokines (5-8), has simplified investigations into the mechanisms of B cell growth and maturation that are dependent on the cross-linking of surface Ig (sIg). It is only the ontogenetically late appearing Lyb-5+ murine splenic B cells, however, that proliferate in response to anti-Ig antibodies, whereas B cells of the Lyb-5- phenotype obtained from neonatal mice or from mice with the xid immune defect cannot be induced to proliferate in response to this stimulus (1, 9, 10). Thus, the analysis of B lymphocyte physiology of the Lyb-5- B cell population has been hampered by the unavailability of B cell stimulants that mimic an antigen-induced sIg cross-linking event that leads to B cell activation. The inability of soluble anti-Ig antibodies to induce the proliferation of Lyb-5- cells has been particularly difficult to explain because these cells can be induced to increase in size (11) and to show an increase in their expression of surface Ia (sIa) after exposure to anti-Ig (12). Apparently, therefore, these cells are not entirely refractory to this stimulus but are simply unable to progress to the latter stages of cell activation. In view of our observations that the cells of CBA/N mice cannot respond to soluble trinitrophenyl-(TNP) dextran or TNP-polyacrylamide (13) but can respond to insolubilized forms of these antigens, we evaluated their ability to respond to insolubilized anti-Ig. In this paper we report that B cells from CBA/N mice can be stimulated to proliferate in response to anti-Ig conjugated to Sepharose beads, but in contrast to normal B cells they need to be stimulated with beads expressing a high-epitope density of anti-Ig antibodies.
Inhibition of macrophage tumoricidal activity by immune complexes and altered erythrocytes.
Authors: Esparza I , Green R , Schreiber R D
Published: December 2022

Engagement of the macrophage membrane by biologic particles including insoluble immune complexes inhibited the development of lymphokine-mediated nonspecific tumoricidal activity by murine macrophages. The degree of inhibition was dependent on the dose of particles and the lymphokine concentration. Inhibition was not due to macrophage cell death or to diminution of cell adherence after ingestion of the immune complexes. Soluble immune complexes were not inhibitory, although approximately 10% of the complexes became cell-associated. Monomeric or heat-aggregated IgG was also not inhibitory. IgG-opsonized erythrocytes (EA) were inhibitory and inhibition was dependent on the degree of opsonization. In contrast, nonopsonized erythrocytes (E), which did not bind to macrophages, were not inhibitory. Phagocytosis of glutaraldehyde-treated E or E carrying IgM antibody and complement (EAC) also led to a reduction of tumorilytic activity. Insoluble immune complexes were inhibitory when added either before or after lymphokine. Phagocytosis was neither sufficient nor necessary to cause inhibition because 1) ingestion of polystyrene latex beads did not diminish tumoricidal activity, and 2) macrophages plated on IgG-coated surfaces were inhibited with respect to the tumoricidal function. Inhibition was not affected when indomethacin (10(-6) M) was included in the assay, which indicated that prostaglandins were not involved in the process. Thus, macrophage tumoricidal responsiveness may be compromised by interaction of biologic substances with macrophage plasma membranes. This process may thereby inactivate an important host defense mechanism against neoplastic cells.
Polyclonal activation of the murine immune system by an antibody to IgD. IV. In vivo activation of B lymphocytes from immune defective CBA/N mice.
Authors: Muul L M , Scher I , Mond J J , Finkelman F D
Published: December 2022

Previous studies with BALB/c mice have established that the injection of a goat antibody to IgD (GaM delta) induces splenic B lymphocytes to undergo T-independent, polyclonal increases in cell surface (s) Ia expression, size, and DNA synthesis 1 day after injection, as well as T-dependent maintenance of this activation and differentiation into sIgG1+ cells and IgG1-secreting cells 6 to 7 days after injection. Because B lymphocytes from mice homozygous or hemizygous for the CBA/N X-linked immune defect fail to proliferate in vitro when cultured with soluble anti-Ig antibodies, yet can make in vivo primary antibody responses to T-dependent antigens, we studied the effects of injecting (CBA/N X DBA/2)F1 male mice (immune defective) and (CBA/N X DBA/2)F1 female mice (phenotypically normal) with 800 to 1600 micrograms of GaM delta. B cells from immune defective mice demonstrated definite but distinctly subnormal increases in B cell size, DNA synthesis, and sIa expression 1 to 5 days after GaM delta injection, but by day 7 showed increases in these parameters as well as in the percentages of splenic sIgG1+ cells and IgM-secreting cells that were similar to those exhibited by the immunologically normal mice. However, IgG1 secretion by the immune defective mice was at this time only one-fourth to one-half as great as that observed with normal mice. Our data raises the possibility that the differentiation of B cells into IgG1-secreting cells may be more dependent upon the GaM delta-induced activation steps that are defective in CBA/N mice than is the differentiation of B cells into IgM-secreting cells or into sIgG1 cells.
Characterization of early B lymphocyte precursors present in long-term bone marrow cultures.
Authors: Dorshkind K , Phillips R A
Published: December 2022

Lymphoid precursor cells are present in long-term bone marrow cultures (LTBMC), but their differentiation into mature lymphocytes is blocked. A quantitative assay for B cell precursors in LTBMC, which gives a linear relationship between the number of grafted LTBMC cells and the frequency of B cell colony forming units (CFU-B) in the spleen and bone marrow of immunodeficient CBA/N mice 19 days after reconstitution, is described. Characterization of the B cell precursor indicates that this assay is detecting a very early precursor and not a B lymphocyte or a late pre-B cell. This conclusion is based on the observations that a) pre-B cells transformable by Abelson murine leukemia virus are not present in LTBMC by 3 days postrecharge and CFU-B are absent by 6 days postrecharge; b) late B cell progenitors capable of rapid repopulation of irradiated CBA/N mice are not present in LTBMC, since a lag in the kinetics of B cell reconstitution in animals grafted with LTBMC cells is observed compared with fresh bone marrow cells; c) the B cell precursors in LTBMC have high proliferative potential, since they can stably repopulate recipient mice for at least 8 wk postreconstitution and through two serial passages in irradiated CBA/N recipients; and d) the B cell precursors are large, rapidly sedimenting cells as determined by velocity sedimentation. The serial transplantation experiment further shows that a split is often observed between lymphoid and myeloid reconstituting ability of LTBMC cells. The LTBMC B cell precursor may be a pluripotent stem cell or a lymphoid stem cell, although its differentiative potential remains to be determined.
In vitro analysis of allogeneic lymphocyte interaction. VIII. Characterization of helper components of allogeneic effect factor (AEF) that activate Lyb5+ and Lyb5- B cells to respond to thymus-dependent and thymus-independent antigens.
Authors: Delovitch T L , Kaufman K , Gorczynski R D , Sinclair G D
Published: December 2022

We analyzed the ability of an allogeneic effect factor (AEF), produced using alloactivated A.SW (H-2s) responder T cells and irradiated A/WySN (H-2a) T cell-depleted stimulator spleen cells, to enhance the responsiveness of Lyb5+ and Lyb5- B cells to thymus-dependent (TD) and thymus-independent type 1 (TI-1) and type 2 (TI-2) antigens. We found that normal adult male CBA/CaHN (Lyb5+ + Lyb5-) B cells are activated by unfractionated AEF in primary in vitro IgM antibody responses to the SRBC (TD), TNP-LPS (TI-1), and TNP-Ficoll (TI-2) antigens. Adult male xid CBA/N (Lyb5-) B cells are activated by unfractionated AEF to respond to TNP-LPS but to neither SRBC nor TNP-Ficoll. Gel filtration of AEF on ACA 54 resolves several helper components. One component, which is I-Ak restricted in its activity and may represent a secreted form of an Ia antigen T cell receptor, interacts with histocompatible and functionally competent CBA/CaHN or CBA/N antigen-presenting cells to activate a primary anti-SRBC response of CBA/CaHN B cells but not of CBA/N B cells. A second antigen-nonspecific and H-2-nonrestricted AEF component, which consists of interleukin 2 and possibly also interleukin 1, activates anti-SRBC and anti-TNP-Ficoll responses of both CBA/CaHN B cells and CBA/N B cells. Such CBA/N B cell responses were potentiated by this AEF component only after its biochemical fractionation and only in the presence of a limiting number of T cells. These data indicate that both Lyb5+ and Lyb5- B cells are responsive to TD, TI-1, and TI-2 antigens in the presence of ancillary antigen-nonspecific help. They are also consistent with the notion that T helper cell activation of Lyb5+ B cells is H-2 nonrestricted and that T helper cell activation of Lyb5- B cells is H-2 restricted.
Murine hybridomas secreting natural monoclonal antibodies reacting with self antigens.
Authors: Dighiero G , Lymberi P , Mazié J C , Rouyre S , Butler-Browne G S , Whalen R G , Avrameas S
Published: December 2022

Spleen cells from nonimmunized BALB/c mice were fused with two nonsecreting myeloma lines. The hybrids were selected in HAT medium and screened for Ig production and for antibody activity against actin, tubulin, myosin, thyroglobulin, myoglobin, spectrin, dsDNA, fetuin, and transferrin. Among 161 hybrids secreting Ig, three were found to react with DNA, one with thyroglobulin, and one mainly with myosin. Two of these hybrids could be propagated and further characterized. On the basis of inhibition experiments, one was found to be directed against dsDNA; the other was directed mainly against myosin but at the same time reacted significantly with actin, tubulin, spectrin, and dsDNA. Reactivity with myosin seemed to be concentrated in the light meromyosin subfragment, known to be rich in alpha-helical structure. These results indicate: 1) There are reactive B cell clones directed against self antigens. 2) The antibody specificities found for these antibodies are very similar to those found for natural antibodies in normal human serum and for human monoclonal Ig. 3) The widespread reactivity found for the clone mainly reacting with myosin raises the possibility that the determinant recognized by this antibody is a conformational structure that possibly is associated with alpha-helical structures.
Interleukin 2 is not sufficient for the continuous growth of cloned NK-like cytotoxic cell lines.
Authors: Olabuenaga S E , Brooks C G , Gillis S , Henney C S
Published: December 2022

Interleukin 2 (IL 2) has been strongly implicated as the agent responsible for the continuous growth of T cell lines in vitro. In the present study we confirmed that IL 2 alone could support the growth of a widely used cytotoxic T cell line. In contrast, we found that IL 2 was not sufficient to support the long-term growth of cloned NK-like cytotoxic lymphocyte cell lines. Whereas such lines would grow indefinitely in concanavalin A-induced mouse spleen cell supernatant, they would only grow for short periods (2 to 3 days) in the IL 2-containing supernatant of phytohemagglutinin-stimulated LBRM-33 tumor cells, or in IL 2 partially purified from spleen cell or LBRM-33 supernatants. The addition of concanavalin-A or interferon (type beta or gamma) to these supernatants did not improve growth. By contrast, the NK-like cells proliferated equally well in a short-term (24-hr) assay, irrespective of the source of IL 2 (spleen or LBRM-33 supernatant, or partially purified IL 2). Furthermore, the NK-like cells readily depleted IL 2 from the medium, either during growth at 37 degrees C or by absorption at 4 degrees C. It is concluded that at least some cytotoxic cell lines require both IL 2 and other, as yet unidentified, spleen cell-derived factors for long-term growth.
Localization of the phosphocholine-binding sites on C-reactive protein by immunoelectron microscopy.
Authors: Roux K H , Kilpatrick J M , Volanakis J E , Kearney J F
Published: December 2022

C-reactive protein (CRP) was reacted with monoclonal IgG antibody or Fab antibody fragments directed against the phosphocholine- (PC) binding site or a second unrelated site. The resulting immune complexes were viewed by a negative stain immunoelectron microscopy technique. Monoclonal anti-PC-binding site antibody bound to a single epitope on each of the five CRP subunits. The orientation of the PC-binding sites was determined to be slightly medial to one of the planar faces (A-face) of the molecule. The second monoclonal antibody, which was not PC-binding site related, bound to epitopes (one per CRP subunit) that were located slightly lateral to the other planar face (B-face) of the CRP molecule, i.e., opposite of the PC-binding site. Thus, the PC-binding site and the non-PC-binding site are oriented nearly perpendicular but on opposite sides with respect to the plane of the CRP molecule. The functional significance of this configuration is discussed.
Biosynthesis and postsynthetic processing of human C-reactive protein.
Authors: Tucci A , Goldberger G , Whitehead A S , Kay R M , Woods D E , Colten H R
Published: December 2022

Human C-reactive protein (CRP) is one of several plasma proteins that increase after tissue injury or inflammation. The magnitude of the increase in CRP (100 to 1000-fold over the resting state) makes this an excellent model for studies of eukaryotic gene control. Accordingly, the biosynthesis and postsynthetic processing of human CRP was examined under cellfree conditions and in Xenopus oocytes injected with liver mRNA. The primary translation product is larger than native serum CRP by an 18-amino acid amino terminal extension. The sequence of this signal peptide was derived from nucleotide sequencing of a 1.8-kilobase (Kb) CRP-specific cDNA clone. Northern blot analysis revealed a CRP mRNA of approximately 2.2 Kb, a size more than three times that required (615 bases) to code for the primary translation product. These data form the basis for study of molecular control of the acute phase response.
Identification of the apparently lymphocyte-specific human liver-derived inhibitory protein (LIP) as cytoplasmic liver L-arginase.
Authors: Brusdeilins M , Hapke C , Huberts H H , Schumacher K
Published: December 2022

This paper describes the identification of a human liver-derived inhibitory protein (LIP), which has recently been purified, as cytoplasmic liver arginase. Arginase activity was purified to homogeneity parallel to lymphocyte proliferation inhibitory activity. The reaction products were identified by thin-layer chromatography to be ornithine and urea from arginine. The enzyme activity could be increased by the addition of manganese ions, and the inhibitory effect on cell proliferation could be reversed by additional arginine. An antiserum against LIP cross-reacted with cytoplasmic calf liver arginase.
In vitro induction of cytotoxic polymorphonuclear leukocytes by supernatant from a concanavalin A-stimulated spleen cell culture.
Authors: Inoue T , Sendo F
Published: December 2022

Rat polymorphonuclear leukocytes (PMN) pretreated with supernatant of a spleen cell culture stimulated with concanavalin A (Con A sup) inhibited 3H-thymidine uptake of various syngeneic, allogeneic, and xenogeneic tumor cells. Con A sup-treated PMN were cytostatic not only to tumor cells but also to embryonal fibroblasts and normal Con A blasts. Stimulated PMN also killed some tumor cells, as shown by 3H-uridine release assay. Cytostasis by Con A sup-treated PMN began at a very early phase of incubation, but in the cytolysis assay, incubation for more than 12 hr was required to obtain significant killing. The time required for activation of cytostatic PMN by Con A sup was short (5 min was enough) if high titers of Con A sup were used for activation. PMN-stimulating activity of Con A sup was not abrogated by treatment at 60 degrees C for 30 min or by change of pH from 1 to 11. The mechanisms of cytotoxicity by Con A sup-treated PMN are discussed.
Intracamerally induced concomitant immunity: mice harboring progressively growing intraocular tumors are immune to spontaneous metastases and secondary tumor challenge.
Authors: Niederkorn J Y , Streilein J W
Published: December 2022

Intracameral inoculation of allogeneic P815 mastocytoma cells (DBA/2) into BALB/c mice resulted in progressively growing intraocular tumors. Intraocular tumor cells disseminated rapidly to the spleen and cervical lymph nodes, yet extraocular nests of tumor cells never developed into fulminant tumors. Further experiments showed that tumor cells were continuously seeded from the primary intraocular tumor and were rapidly cleared from extraocular sites. Hosts harboring intraocular P815 mastocytomas rejected tumorigenic doses of P815 cells inoculated subcutaneously or even into the contralateral anterior chamber. This systemic tumor immunity was found to be radiosensitive and T cell dependent. Spleen cells from animals with progressively growing intraocular tumors protected recipient mice challenged with intracamerally inoculated tumor cells and thus suggests that a cell-mediated mechanism is the underlying basis for this form of tumor immunity. The data indicate that mice harboring progressively growing intraocular tumors develop a potent state of "concomitant immunity," that prevents the development of metastases, yet is ineffective in controlling the primary tumor.
Comparison of approaches for augmenting the serologic response to the individually specific methylcholanthrene-induced sarcoma-Meth A: pretreatment with cyclophosphamide is most effective.
Authors: Livingston P O , DeLeo A B , Jones M , Oettgen H F
Published: December 2022

We have previously reported the production of antisera against a highly restricted antigen expressed on the BALB/c sarcoma Meth A. Because induction of the antibody required many vaccinations with irradiated and unirradiated Meth A cells over a prolonged period, we have investigated methods of improving the efficiency of producing Meth A antibody in BALB/c mice. Three general approaches were used: immunizing with irradiated Meth A cells mixed with adjuvants, immunizing with irradiated Meth A cells modified by treatment with chemicals, or administration of tumor cell vaccines in conjunction with low dose cyclophosphamide. These vaccine preparations were injected subcutaneously into groups of BALB/c mice five to six times at 2-wk intervals. Sera from all mice were screened for reactivity to Meth A by complement-dependent cytotoxicity, protein A, and mixed hemadsorption assays. Twenty-three vaccine preparations containing adjuvants or modified cells were tested in individual groups of mice. Mice in some groups receiving adjuvants and in all groups receiving modified cells produced antibody, but only after four to six vaccinations. In contrast, nine of the 14 mice immunized with irradiated Meth A cells (unmodified and without adjuvant) in conjunction with 10 or 100 mg/kg body weight of cyclophosphamide, and all nine of the mice receiving 25 mg/kg cyclophosphamide made Meth A antibodies after only one or two vaccinations. The titer of antibodies produced after one treatment with cyclophosphamide and irradiated Meth A cells was at least as high as that achieved after five or six vaccinations in our other trials. The specificity of these antibodies for the Meth A antigen was established by absorption analysis. We conclude that treatment with cyclophosphamide before vaccination is highly effective in augmenting the humoral immune response to the Meth A antigen.
IgA responses in xid mice: oral antigen primes Peyer's patch cells for in vitro immune responses and secretory antibody production.
Authors: Kiyono H , Mosteller L M , Eldridge J H , Michalek S M , McGhee J R
Published: December 2022

Because the gut-associated lymphoreticular tissue (GALT), e.g., Peyer's patches (PP), of X-linked immunodeficient (xid) mice possesses a subpopulation of mature B cells, we have characterized the ability of xid mice to respond to the thymic-dependent antigen sheep erythrocytes (SRBC) given by the oral route. Gastric intubation of SRBC to xid (CBA/N X DBA/2) F1 male or CBA/N mice, followed by the in vitro culture of dissociated PP cells with SRBC, resulted in IgM, IgG1, IgG2, and high IgA anti-SRBC plaque-forming cell (PFC) responses. The addition of unprimed PP but not splenic T cells to splenic xid B cell cultures resulted in IgM anti-SRBC PFC responses, suggesting the importance of GALT T cells for support of the immune responses to SRBC by splenic B cells from xid mice. Furthermore, purified PP T cells from SRBC orally primed xid mice supported in vitro IgA anti-SRBC PFC responses in B cell cultures from either the PP or the spleens of nonprimed xid mice. Higher IgA responses, however, occurred in PP, when compared with splenic B cell cultures. Additional evidence that the GALT of xid mice contains functional IgA precursor cells was provided by the finding that cloned H-2k PP T helper cells (PP Th A) supported IgA responses in PP B cell cultures derived from (CBA/N X C3H/HeN) F1 male (xid) mice. On the other hand, splenic B cells from these xid mice, in the presence of PP Th A cells, did not support in vitro responses. These results suggest that unique subpopulations of T cells occur in the GALT of xid and normal mice; one T cell subpopulation may induce immature B cells to become precursor IgA cells in the PP. A separate GALT T cell subpopulation, e.g., isotype-specific helper T cells, effectively collaborates with mature IgA B cells for the induction of IgA responses to orally administered antigen. When xid mice were gastric intubated with SRBC, followed by i.p. injection of SRBC, good splenic IgA anti-SRBC PFC responses were seen. Salivary and serum IgA antibodies were also detected in these xid mice. Nevertheless, the magnitude of the anti-SRBC response in xid mice was lower than that seen in similarly treated normal mice. These studies indicate that the GALT of both xid and normal mice possess unique populations of T cells that support in vitro responses in xid B cell cultures from either the spleen or the PP, which direct the mature B cell populations present toward IgA isotype-specific responses.(ABSTRACT TRUNCATED AT 400 WORDS)
Polarization of NK cell cytoskeleton upon conjugation with sensitive target cells.
Authors: Carpén O , Virtanen I , Lehto V P , Saksela E
Published: December 2022

We studied the cytoskeletal changes in natural killer (NK) cells during conjugate formation, i.e., when NK cells make contact with sensitive vs resistant target cells. F-actin and vinculin were seen to polarize at the contact sites upon conjugation with sensitive K562 cells, whereas in conjugates with resistant Raji target cells such an orientation was an infrequent finding. Myosin and two other cytoskeletal proteins, spectrin and vimentin, on the other hand, showed a random distribution in conjugating NK cells regardless of the target cell type. Hence the cytoskeletal redistribution associated with conjugation seems to be different from the receptor capping phenomenon, which is accompanied by clustering of actin, myosin, vimentin, and spectrin. On the basis of these results it seems probable that the lytic conjugate formation in NK-mediated cytotoxicity is associated with the formation of a specific type of junction that involves actin and vinculin. This cytoskeletal reorganization precedes and could be a prerequisite for the polarization of the cellular secretory apparatus and may be functionally responsible for the required cytokinetic movements.
Peroxidase-positive mononuclear leukocytes as possible precursors of human dendritic reticulum cells.
Authors: Parwaresch M R , Radzun H J , Feller A C , Peters K P , Hansmann M L
Published: December 2022

In this report, we provide evidence that suggests the dendritic reticulum cells (DRC) occurring in germinal centers of lymphatic follicles originate from a distinct endogenous peroxidase-positive mononuclear blood cell subset. The new monoclonal antibody Ki-M4 showed a highly restricted reactivity, tested by immune histochemistry, being confined to DRC, lining cells of lymph node sinuses, and to 0.001% of nonadherent mononuclear blood cells separated at a density of 1.077 g/ml; the latter exhibited endogenous peroxidase activity in cytoplasmic granules. Such granules being specific for myelomonocytic cells implies that DRC may derive from a committed nonadherent subpopulation of this cell line, which in turn originates from bone marrow. The Ki-M4-reactive antigen was found to be destroyed by the majority of fixatives and to resist 4% paraformaldehyde for 10 min and cold acetone for 30 sec. In cell suspensions from human tonsils, Ki-M4 showed strong reactivity with the outer surface of DRC plasma membrane. This observation demonstrates the possibility of using Ki-M4 to separate DRC from cell suspensions in functional tests.
Cyclophosphamide-sensitive contrasuppression in TNP-anterior chamber associated immune deviation (TNP-ACAID).
Authors: Waldrep J C , Kaplan H J
Published: December 2022

Injection of trinitrophenyl (TNP)-modified splenocytes (TNP-Sp) into the anterior chamber of the eye results in systemic tolerance to TNP, a phenomenon termed anterior chamber associated immune deviation (TNP-ACAID). Two distinct suppressor pathways develop after the induction of TNP-ACAID. The primary suppressor pathway (I) is antigen-specific, is mediated by a cyclophosphamide (Cy)-sensitive suppressor T cell (Ts-I), and requires a Cy-sensitive auxillary cell. The secondary suppressor pathway (II) is antigen nonspecific, is mediated by a Cy-resistant suppressor T cell (Ts-II), and requires a TNP-pulsed accessory macrophage. Suppression via pathway II is demonstrable only when Ts-I cells are functionally inactivated by Cy. Furthermore, the addition of T cells from Sp containing active Ts-I inhibits Ts-II. This suppression of a suppressor cell (i.e., contrasuppression) is mediated by either Ts-I or a third T cell population, which is also Cy sensitive.
Studies of congenic MRL-Ipr/Ipr.xid mice.
Authors: Steinberg E B , Santoro T J , Chused T M , Smathers P A , Steinberg A D
Published: December 2022

Highly inbred MRL-Ipr/Ipr.xid congenic mice were bred and compared with their + littermates. The xid-bearing congenics developed lymphadenopathy consisting of dull Ly-1+ T cells and impairment of cellular proliferation and IL 2 production in response to the T cell mitogen Con A. Thus, the lpr gene was fully expressed. The xid gene, however, was also expressed as indicated by the failure to respond to immunization with TNP-Ficoll and flow cytometric analysis of splenic B cells. The xid gene was associated with a marked reduction in IgM anti-ssDNA and anti-nDNA of both classes, and serum Ig-bound gp 70. Kidney disease was markedly retarded as was death from the autoimmune process. These studies suggest that the T cell lymphoproliferation and dysfunction characteristic of MRL-Ipr/Ipr mice is not sufficient to induce accelerated autoimmunity; xid is able to markedly slow the process. The xid gene interferes with the development of a B cell subset necessary for maximum autoantibody production, anti-gp 70 production, and the resultant immune complex renal and cardiac disease. The present finding of protection against accelerated autoimmunity in MRL-Ipr/Ipr mice by xid, coupled with previous demonstrations of protection against autoimmunity in other autoimmune mouse strains, suggests that a common approach to the therapy of systemic lupus may be possible.
Sensitization to epithelial antigens in chronic mucosal inflammatory disease. I. Purification, characterization, and immune reactivity of murine epithelial cell-associated components (ECAC).
Authors: Aronson R A , Cook S L , Roche J K
Published: December 2022

To explore the autoantigenic potential of mucosal epithelium that is the site of several chronic, progressive, inflammatory and yet idiopathic diseases, epithelial cell-associated components (designated ECAC) have been isolated in aqueous-soluble form from everted, inflated loops of murine small intestine, initially characterized biochemically and immunologically, and then purified to homogeneity and studied for a disease association through quantitating, by microcytotoxicity assay, their reactivity with patient mononuclear cells and sera. Hydroxyapatite chromatography successfully separated ECAC into several series of major and minor components, with each series (designated 1, 2A, 2B, and 2C) having a unique chemical profile in terms of total carbohydrate, protein, and specific sugars (sialic acid, fucose, galactose). Furthermore, components within each series were shown not to behave as simple blood group substances antigenically, to be free of contaminating intestinal proteases (less than 0.25 micrograms chymotrypsin or equivalent per milliliter) and to possess shared as well as unique antigenic determinants (1 through 4), all of which appeared to be organ-specific for intestine. Gel filtration on Sephacryl S-200 gave a four-peak elution profile for ECAC consistent with a m.w. for components of 3000 to 232,000. Preparative polyacrylamide gel electrophoresis did isolate individual constituents of ECAC, four of which (P1, P2, P4, and P5) were homogeneous and that could, by a hemagglutination inhibition technique, be shown to possess unique organ-specific antigenic determinants. ECAC-specific reactivity of peripheral blood mononuclear cells and sera from patients in the active phase of a chronic inflammatory disorder involving mucosal epithelium indicated autosensitization had occurred, with involvement of several purified epithelium-derived macromolecules. This reactivity appeared to be antibody dependent, occurred at relatively low effector to target ratios, and was not simultaneously directed to control antigens, isolated from kidney in a manner analogous to that used for ECAC. ECAC, isolated by these techniques, may be sufficiently purified to allow an evaluation of their role in the initiation and/or progression of chronic autoaggressive processes occurring in mucosa.
Identification and quantitation of T lymphocyte subsets found in the spinal cord of the Lewis rat during acute experimental allergic encephalomyelitis.
Authors: Hickey W F , Gonatas N K , Kimura H , Wilson D B
Published: December 2022

Monoclonal antibodies specific for different rat T cell subsets and Ia-positive cells were used in a quantitative morphologic study of the cellular infiltrates in the spinal cords of Lewis rats during acute, actively induced experimental allergic encephalomyelitis (EAE). The predominant cell types in the inflammatory spinal cord lesions are W3/25-positive and Ia-positive cells. The relative percentages represented by each cell type remain quite constant regardless of the degree of clinical illness exhibited by the rat. These data demonstrate a quantitative profile of the infiltrating cells in acute, active EAE, and suggest that the principal inflammatory cells in these lesions are T helper cells and Ia-bearing cells (macrophages, B cells, or activated T helper cells).
Purification and characterization of TNP-specific immunoregulatory molecules produced by T cells sensitized by picrylchloride (PC1F).
Authors: Ptak W , Gershon R K , Rosenstein R W , Murray J H , Cone R E
Published: December 2022

T cell-derived TNP-specific factors associated with immunoregulatory activity were obtained by culture of T cells obtained from mice sensitized by skin-painting with picrylchloride. Culture medium was absorbed to TNP-Sepharose and TNP binding proteins were prepared by elution with TNP. The hapten affinity-purified proteins were characterized by size and charge and were found to be acidic 70,000 m.w. polypeptides that occur as monomers or oligomers. Oligomeric proteins interact with factors produced by mice injected with trinitrobenzenesulfonic acid to form factors that suppress specifically the ability of TNP-sensitized T cells to transfer contact sensitivity to TNP. Monomeric (no more than 70,000 m.w.) molecules do not form suppressor factors but can transfer contact sensitivity to TNP. Moreover, reduction and alkylation of oligomeric molecules inactivates their suppressor activity but causes them to be able to transfer contact sensitivity. The results suggest that T cell-derived antigen-specific molecules may have different effector functions dependent on their oligomeric state.
Fine specificity of cloned insulin-specific T cell hybridomas: evidence supporting a role for tertiary conformation.
Authors: Glimcher L H , Schroer J A , Chan C , Shevach E M
Published: December 2022

Two groups of cloned insulin-specific T cell hybridomas were derived from the fusion of (BALB/c X A/J)F1 T cells with the BW5147 tumor line. Group I responded only to the immunogen pork insulin and failed to respond to rat insulin, which differs only at amino acids A4 and B3. The second group of T cell hybridomas exhibited a broader pattern of reactivity to heterologous insulins because they could be stimulated with the B chain-identical pork, beef, sheep, and human insulins, as well as by isolated oxidized B chain. These hybridomas, however, displayed a much greater reactivity to pork insulin than to beef insulin or to the oxidized B chain. Comparison of the reactivity profiles of these two groups of hybridomas with the three-dimensional structure of the insulin molecule strongly suggested that group I cells were recognizing an immunogenic moiety composed of residues A4 and/or B3 in association with A chain loop determinants and that group II hybrids recognized a moiety composed of the amino acid sequence of the B chain and the A chain loop. Both groups of hybrids were restricted to the high-responder I-Ad allele but could be distinguished by their pattern of alloreactivity. We were unable to show any effect of a panel of monoclonal anti-insulin antibodies on the induction of interleukin 2 secretion by these hybridomas or to demonstrate the presence of idiotypic determinants on these T hybrids by using a panel of anti-idiotypic reagents raised against the monoclonal anti-insulin antibodies.
Antigen-initiated release of platelet-activating factor (PAF-acether) from mouse bone marrow-derived mast cells sensitized with monoclonal IgE.
Authors: Mencia-Huerta J M , Lewis R A , Razin E , Austen K F
Published: December 2022

Mouse bone marrow mast cells sensitized with monoclonal IgE and activated with specific antigen released 2.8 +/- 0.5 ng of platelet-activating factor (1-0-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine) (PAF-acether)/ 10(6) cells. The PAF-acether was identified by its ability to aggregate fully aspirin-treated washed rabbit platelets in the presence of an adenosine diphosphate (ADP)-scavenger complex, by its co-chromatography with [3H]-labeled semi-synthetic PAF-acether and synthetic 1-0-octadecyl-2-acetyl-sn-glyceryl-3-phosphorylcholine, and by its inactivation by phospholipases A2, C, and D and not by lipase A1. The antigen-initiated release of PAF-acether, leukotriene C4 (LTC4), and leukotriene B4 (LTB4), and the secretion of the granule marker beta-hexosaminidase were not diminished by washing the cells before challenge, indicating that they were due to the interaction of antigen with the IgE fixed on the cell membrane and not to phagocytosis of immune complexes formed in the fluid phase. The parallel antigen-induced dose-response relationship, along with the superimposable time-course of the extracellular appearance, of beta-hexosaminidase, PAF-acether, and both leukotrienes indicated that the origin of these diverse mediators was from a common cell type with IgE-Fc receptors. Ethanol extraction of antigen-stimulated bone marrow-derived mast cells revealed the early transient appearance of a cell-associated platelet-aggregating activity, the action of which on platelets, like PAF-acether, was independent of ADP and arachidonic acid metabolism. The cell-associated activity contained a novel product that eluted at 13 min during high performance liquid chromatography (HPLC) (solvent hexane:n-propanol:water, 46:46:8), permitting resolution from PAF-acether and lyso-PAF-acether (1-O-alkyl-sn-glyceryl-3-phosphorylcholine), which eluted at 29 min and 30 min, respectively. The cell-associated material, which differs from lyso-PAF-acether, the putative precursor of PAF-acether, in being active in the bioassay on platelets may represent a newly recognized intermediate in the generation of PAF-acether. As the transiently present cell-associated intermediate has not been previously recognized, its detection may depend upon the relatively unique properties of the bone marrow-derived mast cell system in which IgE-dependent activation leading to product generation is complete within 5 min.(ABSTRACT TRUNCATED AT 400 WORDS)