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J Reimann

Publications and source records attributed to J Reimann.

176 records · Page 10Linked to original sources
PubMed1981

Self-reactive T cells. IV. Self-reactive T cells induce polyclonal differentiation of IgM-producing B cells in vivo and in vitro.

Intravenous injection of lymphoblasts (generated in vitro by different T- or B-specific mitogens) induced a polyclonal activation of IgM-producing B cells in vivo in the spleens of syngeneic recipient mice. This polyclonal differentiation of host-derived B cells to IgM-producing plaque-forming cells was stimulated by host-derived self-reactive T cells activated in the splenic lymphoid cell population in response to the syngeneic lymphoblast graft. We found a stable factor in the supernatants of cultures of proliferating self-reactive T cells that induced (antigen-independent) polyclonal maturation, but not proliferation of IgM-producing B cells.

Animals↗
PubMed1981

Self-reactive T cells. V. T cell-mediated suppression of B cell responsiveness to LPS.

The intravenous injection of polyclonally activated lymphoblasts elicited a proliferative T cell reaction in the spleens of syngeneic recipient mice. In the non-fractionated cell populations obtained from these spleens 6 days after lymphoblast transfer, the LPS-induced proliferation and differentiation of B cells in vitro was suppressed. This suppressive effect was mediated by T cells, as i) treatment with anti-Thy-1 antiserum plus complement restored responsiveness of B cells to LPS in the spleen cell population that had responded in vivo to a syngeneic lymphoblast graft, and ii) the responsiveness of B cells to LPS was not impaired in non-fractionated spleen cell populations of nu/nu mice injected with syngeneic lymphoblasts. The relationship of this nonspecific T suppressor cell activity to the previously described non-specific T helper cell activity for B cell activation is discussed.

Animals↗
PubMed1981

Studies on T-lymphocyte activation. I. Is competence inductions in thymocytes by phorbol myristate acetate, an accessory cell-independent event?

The effect of phorbol myristate acetate (PMA) on lectin-induced murine thymocyte activation was studied. PMA itself failed to stimulate thymocyte proliferation, but potentiated concanavalin A (Con A)-induced thymocyte activation. A brief incubation of thymocytes with PMA changed the responsiveness of these cells to an optimal mitogenic dose of Con A present during the entire subsequent culture period. Further studies showed that PMA induced in a dose-dependent way within 30 min. an optimal competence of thymocytes to respond to the T-cell growth factor interleukin-2 (IL-2). In contrast to lectin-triggered competence induction, PMA-triggered induction of competence in thymocytes seemed to be independent of accessory cells.

Animals↗
PubMed1981

Interleukin-2 allows in vivo induction of anti-erythrocyte autoantibody production in nude mice associated with the injection of rat erythrocytes.

Mice injected with rat red blood cells developed anti-erythrocyte autoantibodies detectable by a direct Coombs' test. Nude mice injected with rat red blood cells did not develop a Coombs-positive state, but nude mice injected with rat red blood cells plus the T cell helper factor, interleukin-2, produced autoantibodies to autologous mouse erythrocytes. The simultaneous injection of rat red blood cells and allogeneic spleen cells induced an early and vigorous autoantibody response in athymic nude mice as well as in euthymic control mice. These results are interpreted as indicating the possibility of an interleukin-2-stimulated in vivo differentiation (or clonal expansion) of helper T cells in nude mice in response to heterologous erythrocytes which could mediate an autoimmune B cell response.

Animals↗
PubMed1980

"Self-reactive" T cells. I. In vivo reaction of T cells to transferred polyclonally activated syngeneic and autologous lymphoblasts.

Polyclonally activated splenic lymphocytes (generated in mitogen-stimulated cultures) were transferred to syngeneic or autologous recipient mice. Injection of cells into the footpad of syngeneic recipients induced a regional response in the ipsilateral popliteal lymph node; intravenous cell transfer elicited a systemic splenomegaly reaction. These reactions displayed a linear log number of transferred cells/response relationship in syngeneic and autologous systems. The kinetic and magnitude of the regional response to syngeneic lymphoblasts ands to allogeneic spleen cells were comparable. No difference was apparent in the phenomenology of the in-vivo responses to syngeneic lymphoblasts induced by various T- or B-cell mitogens. The in-vivo response was: 1. stimulated by large-size lymphoblasts; and 2. mediated by host T cells. Data excluded a direct involvement of mitogen or heterologous serum constituents in tissue culture medium in the described reaction. Experimental evidence argues against the involvement of virus components in the observed phenomenon.

Animals↗
PubMed1980

"Self-reactive" T cells. II. Transferred syngeneic lymphoblasts induce T "stimulator" cells in vivo, to which syngeneic T cells "respond" in a syngeneic MLC in vitro.

Splenic T cells, engaged in an in-vivo "response" to transferred syngeneic lymphoblasts, displayed an extensive proliferative activity if cultured in vitro. These cells (blocked by mitomycin C) were "stimulator" cells in a one-way syngeneic mixed lymphocyte culture (S-MLC). "Responder" cells were derived form spleens of syngeneic (sex and age matched) mice. Fractionation studies showed that "stimulator" and "responder" cells in the investigated S-MLC were nylon-wool non-adherent and sensitive to treatment with anti-Thy-1 antiserum and complement, i.e. were cells of the T lineage. Coculture experiments demonstrated that direct cell contact is required to trigger a proliferative "response" in the S-MLC. Fetal calf serum-supplemented tissue-culture medium supported "responder" cell proliferation, normal mouse serum-supplemented medium did not. The in-vivo generation of a T-cell population, which could "stimulate" a syngeneic T-cell "response" in the S-MLC in vitro, was investigated.

Animals↗
PubMed1980

"Self-reactive" T cells. III. In vitro restimulation of T cells, "responding" in vivo or in vitro to syngeneic lymphoid cells.

Polyclonally activated lymphoblasts, transferred to syngeneic recipient mice, elicited a host T-cell-mediated "response" in vivo. These T cells, which "responded" in vivo to syngeneic lymphoblasts (i.e. in vivo primed "responder" T-cell population), acquired the capacity to "stimulate" a "response" of syngeneic T cells in vitro in a syngeneic one-way mixed lymphocyte culture, S-MLC (i.e. in vitro primed "'responder" T-cell population). We now describe the presence of memory and specificity in these two types of "self-reactive""responder" T-cell populations. This is investigated in in vitro "restimulation" experiments with mitomycin-blocked syngeneic and allogeneic lymphoid cells of various origin. "Self-reactive" T cells could be restimulated repeatedly (over many weeks) with mitomycin-blocked syngeneic lymphoid-cell populations, but not with mitomycin-blocked allogeneic normal spleen cells. "Self-reactive" T cells "responded" to syngeneic large activated lymphoblasts, as well as to syngeneic small resting lymphocytes. We found no "responder" T-cell reactivity specific for the mitogen that induced syngeneic "stimulator" cell populations. Both populations of "self-reactive" T cells displayed reactivity to mitogen-induced allogeneic lymphoblasts.

Animals↗
PubMed1979

In vitro proliferation of haemopoietic cells in the presence of adherent cell layers. I. Culture conditions and strain dependence.

The culture system, in which a marrow-derived adherent cell population, established in vitro, exerts a long-term promoting influence on proliferation of haemopoietic cells, is reproduced. Essential parameters of the system are investigated; it is confirmed that the system is critically dependent on horse serum, and on the in vitro age of the adherent cell layer. The growth-promoting effect on haemopoietic cells seems to be independent of the number of marrow cells per culture flask initially inoculated into the cultures to establish the adherent cell layer. In vitro established marrow-derived adherent cell layers from RFM (H-2f) and BALB/c (H-2d) mice can promote the long-term proliferation of syngeneic and allogenic haemopoietic cells; haemopoietic marrow cells from C3H (H-2k) cannot be maintained on syngeneic or allogeneic (BALB/c, H-2d) adherent cell layers; adherent cell layers of C3H (H-2k) can maintain haemopoietic cells of the H-2d (BALB/c) genotype. This culture system does not reproduce the in vivo phenomenon of allogeneic resistance. The relevance of these findings to the suggestion that the growth-promoting activity of adherent marrow cells on haemopoietic stem cells in vitro duplicates aspects of the in vivo haemopoietic microenvironment is discussed.

Animals↗
PubMed1979

In vitro proliferation of haemopoietic cells in the presence of adherent cell layers. II. Differential effect of adherent cell layers derived from various organs.

Mouse bone marrow-derived adherent cell populations promoted proliferation of haemopoietic cells in vitro in a liquid culture system for at least 4 weeks. Adherent cell layers derived from other haemopoietic organs (foetal liver, adult spleen) and fibroblasts from embryonic tissues did not maintain haemopoietic cells in this system. Medium, conditioned by adherent cells derived from foetal liver, spleen and embryonic tissues displayed a considerable colony stimulating activity (CSA). Marrow-derived adherent cells produced no detectable CSA. A possible relationship between the in vitro expression of a growth-promoting activity of an adherent cell population on haemopoietic cells, and its endogenous CSA production, is discussed.

Animals↗
PubMedDate not supplied

Comparison between hepatitis B surface antigen (HBsAg) particles derived from mammalian cells (CHO) and yeast cells (Hansenula polymorpha): composition, structure and immunogenicity.

The composition, structure and immunogenicity of hepatitis B surface antigen (HBsAg) particles derived from Chinese hamster ovary (CHO) cells and from cells of the yeast Hansenula polymorpha were compared. The particles were similar in size distribution (mean 20-33 nm), in shape (spherical), in gross composition (protein to lipid weight ratio of 60:40), and in types of lipids (phospholipids > > sterols = sterol esters = triacylglycerols). Differences related to genetic engineering and type of host cells were found in peptide and lipid compositions. CHO-HBsAg has three peptides: S, M and L, each in two forms of glycosylation, while the Hansenula-HBsAg has only the nonglycosylated S peptide. The electrical surface potential at the lipid/water interface of HBsAg derived from Hansenula is more negative than that of HBsAg derived from CHO, which was close to neutrality. Although the numbers of cysteine residues (all in the S peptides) are identical (14), 11 of them are free thiols in the CHO-HBsAg, compared with three to four in the Hansenula-HBsAg. The fact that 85% of the phospholipids are hydrolyzed by phospholipase C and that all the aminophospholipids react with trinitrobenzenesulfate suggests that the particles derived from both cell types are either leaky vesicles or have a lipoprotein-like structure. Subcutaneous injection into mice of fluorescein-isothiocyanate-labeled HBsAg particles from both sources resulted in their accumulation in the marginal sinus of lymph nodes. The humoral responses to subcutaneous injection into mice of CHO- and Hansenula-HBsAg were similar: however, the cytotoxic T lymphocyte response to CHO-HBsAg was lower.

Animals↗
PubMedDate not supplied

Routes of plasmid DNA vaccination that prime murine humoral and cellular immune responses.

Induction of humoral and MHC (major histocompatibility complex)-I-restricted, cytotoxic T lymphocyte (CTL) responses of Balb/c mice to the small hepatitis B surface antigen (HBsAg) were studied with a protein antigen or a DNA vaccine. Different routes were used to deliver the HBsAg-encoding plasmid DNA or the recombinant HBsAg particles: different doses of expression plasmid DNA (10 micrograms or 100 micrograms per mouse) or of recombinant HBsAg lipoprotein particles were injected into different (normal or regenerating) muscles (m. tibialis anterior and m. quadriceps), into subcutaneous tissue (at the base of the tail), into the peritoneal cavity, or intravenously (into the tail vein). At different time points post-vaccination, the induction of HBsAg specific, MHC-I-restricted CD8+ T cells and of serum antibodies to HBsAg was monitored. The data show that the intramuscular and subcutaneous but not the intravenous and intraperitoneal injection of 'naked' DNA efficiently and reliably primes cellular and humoral immune responses. In contrast, recombinant HBsAg particles injected by all four routes (without adjuvants) efficiently primed specific humoral and CTL responses. These data demonstrate that the choice of routes to deliver 'naked' plasmid DNA for obtaining efficacious immunogenicity of the expressed antigen is restricted.

Animals↗
PubMedDate not supplied

The pregnancy-related dreams of pregnant women.

BACKGROUND: This study examined the frequency and nature of pregnancy-related dreams in pregnant women in a family practice center and assessed the extent such dreams were discussed with providers of prenatal care. METHODS: Pregnant women 18 years of age or older who were receiving prenatal care at the University of Missouri-Columbia Family Medical Care Center responded to a two-page self-administered questionnaire. The major variables measured were frequency of pregnancy-related dreams, frequency of frightening dreams, content of dreams, and discussion of dreams. Health professionals providing prenatal care to these women were also surveyed. RESULTS: Eighty-eight pregnant women, 41 family physicians, and 3 nurse practitioners participated in the study. Dreams about their pregnancy or baby were reported by 59 (67 percent) of 88 pregnant women, of whom 22 had experienced at least one frightening dream. Seventeen women reported being upset by a dream. The frequency of dreams increased with advancing gestational age. The content of the most common dream involved conflict with the father of the baby. Most women had talked to another person about their dreams, usually the baby's father. Only 2 women told their physicians about the pregnancy-related dream. One-half of the providers of prenatal care reported discussing pregnancy-related dreams with a pregnant patient at least once during their careers. CONCLUSION: Dreams about their pregnancy or baby occurred frequently in pregnant women and could be a neglected source of information about the psychological state of the patient.

Adolescent↗