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1.
In vitro sensitization to transplantation antigens. VII. Enhanced graft-vs-host activity of in vitro allosensitized lymphoid cells 总被引:2,自引:0,他引:2
We have previously demonstrated that C57BL/6J lymphoid cells sensitized in vitro to C3H/He transplantation antigens, present on macrophage monolayers, can transfer an accelerated C3H allograft response to recipient C57 mice. The present report indicates that C57 lymphoid cells sensitized to C3H alloantigens, present on macrophage monolayers, can also mediate a graft-versus-host (GVH) reaction in (C3H × C57) F1 newborn mice. This GVH reaction is of greater magnitude than that produced by noncultured C57 cells. The magnitude of the augmented GVH reaction produced by cultured C57 cells is dependent on the source of lymphoid cells: lymph node, spleen, and bone marrow cells are consistently more active than cultured thymus cells—the reduced capability of cultured thymus cells to mediate the GVH reaction parallels their reduced ability to transfer allograft immunity. To test whether monolayers, other than macrophages, can sensitize lymphoid cells in vitro we incubated C57 lymphoid cells on C3H-derived L cells. Lymph node cells incubated with L cells demonstrate an increased GVH reaction in newborn mice. The in vitro sensitization of spleen and bone marrow cells on L cells is less consistent. Thymus cannot be sensitized by L cells. Monolayers of L cells are therefore not as efficient a sensitizing source as macrophages. 相似文献
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Michael Kokkinidis Metaxia Vlassi Yannis Papanikolaou Dina Kotsifaki Adrian Kingswell Demetrius Tsernoglou Hans-Juuml;rgen Hinz 《Proteins》1993,16(2):214-216
Six variants of the ROP protein, designed with the aim to analyze by X-ray crystallography loop formation and core packing interactions in 4-α-helical bundles- have been purified and a search of their crystallization conditions has been carried out. Five mutants yield crystals that are suitable for medium to high resolutionX-ray diffraction studies. For all mutants crystal size- sensitivity to X-irradiation and diffraction limit are correlated to their stability as determined by differential scanning calorimetry- in a manner which is not yet understood in detail. © Wiley-Liss, Inc. 相似文献
4.
Argyris Demetrius Kaliafas Vassilis John Marmaras Constantin Christodoulou 《Development genes and evolution》1984,194(1):37-43
Summary The developmental profile of the major haemolymph proteins (ceratitins) inCeratitis capitata was studied. Ceratitin concentration in the haemolymph decreases dramatically during the last days of pupal life, while the amounts of ceratitins in whole organism extracts remain unchanged. By electrophoretic, immunological and immunofluorescence techniques it was revealed that ceratitins are reabsorbed by the fat body and a fraction of them is deposited in the cuticle. The possible role of ceratitins is discussed. 相似文献
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CS7BL/6 mice were sensitized with an ip injection of allogeneic P-815 mastocytoma cells. Fifteen days later the spleen cells of the tumor allosensitized mice were cultured and tested for their responsiveness to mitogens and alloantigens, and for their ability to generate cytotoxic cells in vitro. The results indicate that 15 day tumor-sensitized spleen cells are hypo-responsive in mixed lymphocyte culture (MLC) with DBA/2 or AKR as stimulating spleen cells. The cells which are hypo-responsive in MLC can proliferate in response to mitogens and they also can generate cytotoxic cells in vitro. MLC reactivity recovers in about 2–3 months which is months after the mice have rejected their tumors. The mechanism of MLC hypo-responsiveness was investigated. The results suggest the presence of a suppressor cell which does not appear to be a macrophage or a B-cell. The suppressor cell can be separated from the cytotoxic cell and therefore appears to be a noncytotoxic T-cell. 相似文献
6.
Murine spleen cells, stimulated in vitro by allogeneic spleen, display a strong proliferative response with the subsequent development of cytotoxic cells. This proliferation and sensitization can be abrogated by the addition of mitomycin-treated or X-irradiated murine DBA/2 mastocytoma cells (P-815). The substance required for this depression of lymphocyte responsiveness is present in the cell-free supernatant fluids of P-815 cultures. The suppression appears to be due to interference with cell proliferation in the mixed lymphocyte culture, because the P-815 also prevents spleen cells from proliferating in response to the mitogens concanavalin A (Con A), lipopolysaccharide (LPS), and phytohemagglutinin (PHA). The significance of these findings is discussed. 相似文献
7.
Previously we have shown that mitomycin-treated P-815 (H-2d) cells (P-815m) inhibit the in vitro response of C57BL/6 spleen cells to mitogens and DBA/2 alloantigens. The present data indicate that P-815m cells also inhibit the response of C57BL/6 spleen cells to AKR (H-2k)-stimulating cells and that the inhibition does not appear to be the result of crowding. Subpopulations of spleen cells obtained by density gradient centrifucation or after renoval of glass-adherent cells are all sensitive to the inhibitory effects of P-815m. We also show that P-815m cells appears to operate both in vitro and in vivo. The experiments characterize the suppression of MLC reactivity by cell-free preparations of sonicated P-815 mastocytoma cells. The results suggest that the inhibition is not removed by ultracentrifugation, ultra-violet irradiation, or dialysis of the sonicate. P-815 sonicates subjected to chloroform extraction, heating at 56 degrees C, 0.1 mu filtration, or treatment with anit-minute virus of mice serum are still inhibitory. This inhibition is resistant to RNAase treatment but destroyed by pronase. P-815 sonicate suppresses the response of C57BL/6 spleen cells to both DBA/2 and AKR-stimulating spleen. Inhibition of MLC reactivity is only seen if P-815 sonicate is added within the first 48 hr after the initiation of culture. These results indicate that the inhibition of MLC by sonicates of P-815 cells is due to a nondialyzable protein whose effects are not H-2 restricted and are acting on the early phase of sensitization. 相似文献
8.
Antigenic variation is a viral strategy exploited to promote survival in the face of the host immune response and represents a major challenge for efficient vaccine development. Influenza viruses are pathogens with high transmissibility and mutation rates, enabling viral escape from immunity induced by prior infection or vaccination. Intense selection from neutralizing antibody drives antigenic changes in the surface glycoproteins, resulting in emergence of new strains able to reinfect hosts immune to previously circulating viruses. CD8+ cytotoxic T cells (CTLs) also provide protective immunity from influenza virus infection and may contribute to the antigenic evolution of influenza viruses. Utilizing mice transgenic for an influenza virus NP366-374 peptide-specific T-cell receptor, we demonstrated that the respiratory tract is a suitable site for generation of escape variants of influenza virus selected by CTL in vivo. In this report the contributions of the perforin and Fas pathways utilized by influenza virus-specific CTLs in viral clearance and selection of CTL escape variants have been evaluated. While transgenic CTLs deficient in either perforin- or Fas-mediated pathways are efficient in initial pulmonary viral control, variant virus emergence was observed in all the mice studied, although the spectrum of viral CTL escape variants selected varied profoundly. Thus, a less-restricted repertoire of escape variants was observed in mice with an intact perforin cytotoxic pathway compared with a limited variant diversity in perforin pathway-deficient mice, although maximal variant diversity was observed in mice having both Fas and perforin pathways intact. We conclude that selection of viral CTL escape variants reflects coordinate action between the tightly controlled perforin/granzyme pathway and the more promiscuous Fas/FasL pathway. 相似文献
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B F Argyris 《Cellular immunology》1979,48(2):398-406
Spleen cells from newborn BDF1 and C57BL/6 mice are tested for suppressor activity in mixed lymphocyte culture. The added spleen cells, treated with mitomycin, suppress both cell proliferation and the generation of cytotoxic cells. Thymus cells from newborn mice have little suppressor activity. Suppressor cells act across an allogeneic barrier, are cortisone-resistant, XR-resistant, T-cells and their activity is inversely correlated to the MLC reactivity in the spleen of the young animal. Incubation of neonatal suppressor cells on macrophage monolayers reduces suppressor cell activity and points to the possible importance of the macrophage in controlling immunological maturation. 相似文献