Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chickens and quails were immunized in parallel either i.v. or intramuscularly (i.m.) with lectin column-purified antigens from chick embryo cells that were transformed in vitro by avain sarcoma virus (ASV). After five to six injections, immunity of the animals was tested by challenge with ASV into the wing webs. Whereas tumor growth was inhibited after i.v. immunization with respect to incidence rate and time of tumor appearance, tumor growth was enhanced after i.m. injection. Animals that were injected with normal cell antigens served as controls. Spleen cells from only those animals that were immunized i.v. exerted a cytotoxic effect in vitro against ASV-transformed cells, whereas spleen cells from i.m. injected animals, in contrast, suppressed such cytotoxicity. The search for serum blocking or arming factors suggested that sera from i.m. injected animals block cellular cytotoxicity whereas sera from i.v. immunized animals render normal spleen cells cytotoxic (arming effect). The use of viruses from different subgroups and of antigens from gp85-lacking ASV-transformed cells indicates that immune effects were obtained against tumor cell surface antigens that differ from the antigen that is involved in virus neutralization (s-gp85).
 ...
PMID:Influence of different routes of anti-tumor immunization: alternative induction of tumor immunity and tumor enhancement. 22 70

Knowledge of the identity, synthesis and secretion of beta-galactoside-binding lectins by leukocytes is of importance because lactosaminoglycans present at the leukocyte cell surface may be physiologically significant lectin receptors that could mediate autocrine or paracrine functions and/or cell adhesion. This paper presents data that show that a previously identified 15.5-16.5 kDa lactose-binding protein synthesized in vitro by human peripheral leukocytes is actually comprised of three different polypeptides. One of these is related to a novel 15 kDa lectin isolated from human spleen and which is synthesized by B lymphoblastoid cells. Spleen contains at least six lactose-binding polypeptides for which the carbohydrate-binding activity is independent of the presence of divalent cations and mercaptoethanol. The splenic 15 kDa polypeptide does not appear to be immunologically related to previously characterized beta-galactoside-binding lectins. It is separable from galaptin, another galactoside-binding lectin (subunit mol. wt 14.5 kDa) by chromatography on DEAE-Sephacel. Western blot analyses and immunoprecipitation/fluorography experiments with metabolically labelled cells showed the presence of the 15 kDa lectin in peripheral leukocytes and in Epstein-Barr virus-immortalized B lymphoblastoid cells. The 15 kDa lectin yielded polypeptide fragments of approximately 6.2 and approximately 8.6 kDa after cyanogen bromide (CNBr) degradation. These fragments were partially sequenced and 12 residues/fragment were identified. A similarity search of the SWISS PROT protein data base did not reveal a relationship of the 15 kDa polypeptide to known lectins, including galaptin.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Identification and synthesis of a novel 15 kDa beta-galactoside-binding lectin in human leukocytes. 142 50

Mistletoe extracts have approval for clinical application. This warrants the quest for the definition of the active substances to optimize their application. Thus, the extent of immunomodulating and antimetastatic activity of the beta-galactoside-specific lectin from mistletoe extract (ML I) was investigated. In BALB/c-mice regular subcutaneous (s.c.) injections of small nontoxic doses of ML I yielded significant enhancement of peritoneal macrophage activity, as measured in chemiluminescence assays, as well as significant weight gain of thymus. Spleen weight, however, increased without statistical significance. To evaluate the anti-metastatic activity of ML I we intravenously (i.v.) inoculated sarcoma L-1 and fibrosarcoma RAW 117-H 10 cells which cause tumor colonization of lungs and livers in BALB/c-mice, respectively. After regular s.c. administration of ML I, the number of lung and liver tumor colonies significantly decreased in both experimental tumor models as compared to control mice which received injections of saline solution. Accordingly, ML I can be regarded as a potent immunomodulating and antimetastatic substance, which seems to be promising for clinical trials in human oncology.
 ...
PMID:Influence of treatment with the immunomodulatory effective dose of the beta-galactoside-specific lectin from mistletoe on tumor colonization in BALB/c-mice for two experimental model systems. 193 21

Mononuclear cells and T-lymphocytes of the blood, spleen and lymph nodes from 48 patients with Hodgkin disease (HD) and blood donors were tested in assays for lectin-dependent (LD) and natural killer (NK) cytotoxic activity. On average, peripheral blood T cell lectin-dependent cytotoxicity differs from that of the donors. However, cytotoxic activity appears to be dependent on the stage of disease; in the IY stage LD cytotoxicity was decreased 2-fold. The lectin-dependent cytotoxicity was also dependent on the histological type of disease and the lowest level (50% of the control level) was associated with the lymphoid depletion type. The cytotoxic activity of T-lymphocytes from the affected areas of the patients' spleen was more marked than that of the unaffected areas. Spleen cell cytotoxicity showed no other correlations. Cytotoxicity of lymphocytes from the affected lymph nodes was drastically lower than activity of blood and spleen lymphocytes. NK activity of the patients' blood and spleen lymphocytes was twice as low as the control level (healthy donors) and did not correlate with stage and/or histological type of disease. The proliferative activity of lymphocytes from 33 HD patients was tested in vitro using allogeneic mononuclear cells from healthy donors or HD patients and/or PHA as stimulators. The response of patients' lymphocytes to alloantigens appeared to be much less affected than response to polyclonal mitogen. Thus, the results obtained by us demonstrate signs of stimulation of the lymphoid system against a background of general immunosuppression in HD.
 ...
PMID:Proliferative activity, lectin-dependent and natural cytotoxicity in blood, lymph node and spleen from patients with Hodgkin's disease. 226 96

Spleen cells that are cultured with interleukin 2 for as short a time as 4 days develop the ability to lyse syngeneic natural killer-resistant tumor cells but not to lyse syngeneic lymphoblasts. When mice were subjected to partial hepatectomy (HEP), the spleen cells exhibited not only an augmentation of natural killer activity, but also an augmentation of in vitro induction of lymphokine activated killer (LAK) cells. Furthermore, the LAK cells exhibited lytic activities against syngeneic lectin-induced lymphoblasts and regenerating liver cells. The sensitivity of regenerating liver cells to lysis by LAK cells was detected as early as one day after HEP, and continued until day 14. Analysis by cell depletion techniques using monoclonal antibodies and complement, as well as discontinuous gradient sedimentation, indicated that the LAK cells activated by HEP were Thy-1+, Lyt-2+, asialo GM1+ and Lyt-1-, lymphocytes with a low density. After the intravenous (i.v.) administration of anti-asialo GM1 before HEP, the in vitro induction of LAK cells was remarkably inhibited.
 ...
PMID:The augmentation of lymphokine-activated killer cells induced by partial hepatectomy in mice. 260 96

The mononuclear cells and T-lymphocytes of the blood, spleen and lymph nodes from 83 patients with Hodgkin's disease and 50 healthy donors were tested in assays for lectin-dependent (LD) and natural killer (NK) cytotoxic activity (CTA). On an average, peripheral blood T cell LD-CTA of patients did not differ from that of the donors. However, the CTA appeared to be dependent on the stage of the disease; in the IVth stage LD-CTA was decreased 2-fold. The LD-CTA was also dependent on the histological type of disease and the lowest level of LD-CTA (50% of the control level) was associated with the "lymphocyte depletion" type. The CTA of T-lymphocytes from the affected areas of the patients' spleen was more marked than that of the unaffected areas. Spleen cell CTA showed no other correlations. The CTA of lymphocytes from the affected lymph nodes was drastically lower than CTA of blood and spleen lymphocytes. The NK activity of the patients' blood and spleen lymphocytes was twice as less as the control level (healthy donors) and did not correlate with a stage and/or a histological type of the disease. It was assumed that in Hodgkin's disease the specific antitumor immunity remains mostly within normal and is decreased only in the last, terminal stage of the disease.
 ...
PMID:[Cytotoxicity of effector cells of the peripheral blood, lymph nodes and spleen in Hodgkin's disease]. 263 27

Spleen cells from mice treated with LS2616 display a highly increased response to the polyclonal T cell lectin ConA. The total number of splenic T cells, and the relative ratios between L3T4+ and Lyt-2+ T cells were not altered by LS2616 treatment. By dissecting the overall ConA response it was found that the number of ConA-inducible, IL-2 reactive T cells was unaffected, while ConA-induced IL-2 production was enhanced after LS2616 treatment. Spleen cells from LS2616 treated mice, depleted of G10 adherent macrophages (M phi) and reconstituted with M phi from untreated mice displayed normal levels of ConA responses. M phi depleted spleen cells from untreated animals, cocultured with M phi enriched populations from LS2616 treated animals resulted in an increased ConA response. Furthermore, spleen cells from treated mice were found to be excellent stimulators for alloantigen-induced T cell responses; when used as responders in MLC, however, these cells were comparable to responders from non-treated animals. Taken together the results demonstrate that LS2616 exerts an immunostimulatory effect on M phi, which indirectly facilitates polyclonal and antigen-specific T cell responses. The possible implications of this observation on various immunoregulatory events are discussed.
 ...
PMID:Mechanism of action of the new immunomodulator LS2616 on T cell responses. 295 30

It was the objective of these experiments to study the time-related changes in the responsiveness of the cellular elements of the immune system following contact with single non-H-2 or multiple H-2 histocompatibility antigens. The reactivity of spleen cells from mice that received injections of spleen cells bearing H-1c, H-3c, H-13a, or H-2b cell membrane alloantigens was characterized at intervals following antigen contact. Spleen cells taken from mice not receiving injections showed no in vitro proliferative or cytolytic responsiveness to cells bearing individual non-H-2 antigens; after in vivo antigen contact with single non-H-2 antigens there was an interval of specific cellular unresponsiveness followed by alternating periods of responsiveness and unresponsiveness. The duration of the unresponsiveness immediately following injection correlated with the strength of the injected antigen--specifically, the stronger the antigen, the shorter the period of unresponsiveness. The data indicate fluctuation in the level of helper T lymphocyte activity, as well as cytotoxic T lymphocyte activity. In contrast, in vitro responsiveness elicited by H-2b antigens with and without prior in vivo antigen contact was of a similar magnitude, and both persisted at a relatively constant level. Suppressor mechanisms were not studied. Of particular interest was the observation that in vivo contact with non-H-2 antigens resulted in suppression of spleen cell production of IL-2 in response to lectin stimulation and fluctuation in the magnitude of the primary response of cytotoxic T lymphocytes to H-2 antigens.
 ...
PMID:Time-response studies of the cellular immune response to cell membrane antigens. 296 10

Spleen cells of X5563 tumor-bearing mice were fractionated with Dolichos biflorus lectin (DBA) into DBA+ (agglutinable with DBA) and DBA- (nonagglutinable with DBA) fractions. The DBA- cells showed antitumor activity specific for X5563 cells in vivo when injected into mice together with X5563 cells (Winn assay) or injected i.p. into mice previously inoculated s.c. with X5563 cells (adoptive transfer) with simultaneous administration of interleukin-2. Both DBA+ and DBA- cells have the cell surface phenotype of Lyt-1-2+, but only DBA- cells exhibit antitumor activity in vivo, while DBA+ cells have stronger cytolytic activity against X5563 cells in vitro than DBA- cells. This cell separation method involving the use of DBA is simple and gives reproducible results and high yields of viable cells.
 ...
PMID:Enrichment of antitumor effector cells that are effective in vivo from spleen cells of tumor-bearing mice through the use of Dolichos biflorus lectin. 309 67

Transplantation tolerance and stable chimerism were established in adult mice conditioned with a short course of total-lymphoid irradiation (TLI) followed by infusion of 30 X 10(6) allogeneic bone marrow cells. Spleen cells of tolerant mice could not exert a proliferative or cytotoxic response against host-type cells in vitro and were unable to induce graft-versus-host reaction in secondary host-type recipients. The degree of suppression assessed by coculturing tolerant splenocytes in vitro in the one-way mixed lymphocyte reaction was quite variable--and, in some cases, was not at all demonstrable, although tolerance was clearly maintained. Suppression, when apparent, could not be ascribed to T lymphocytes. Suppressor cells were found to bind soybean agglutinin and could be separated from the nonsuppressive cells by means of this lectin. Dissociation of the suppressive population (SBA+ cells) from that which is normally alloreactive (SBA- cells) resulted in a suppressor cell-depleted fraction that was still unable to respond to host-type cells but regained reactivity to unrelated cells. Limiting dilution analysis of chimeric splenocytes revealed markedly reduced frequencies of cytotoxic T lymphocyte precursors (CTL-P) directed against host-type cells, as compared with normal splenocytes reacting against the same target cells. This difference was accentuated when these cells were sensitized to host-type target cells prior to plating in limiting dilution cultures. In 1:1 mixing experiments of normal and chimeric splenocytes, there was no evidence of any in vitro suppressive activity to account for hyporeactivity of chimeric cells against host-type cells. Thus, maintenance of TLI-induced tolerance seemed not to be mediated primarily through an active suppressor cell mechanism.
 ...
PMID:Functional clonal deletion versus active suppression in transplantation tolerance induced by total-lymphoid irradiation. 316 Dec 25


1 2 3 4 Next >>