Effects of retinoic acid on the immune system: stimulation of T killer cell induction.

Retinoic acid (RA), a vitamin A derivative with anti-tumor activity, was assayed for its effects on the immune system in mice. High doses of this compound (1000 microgram/mouse/day) have toxic effects and cause depletion on the peripheral lymphoid organs (spleen, thymus) while leaving the bone marrow cells unaffected. Both the in vivo and in vitro induction of cell-mediated cytotoxicity (CMC) to allogeneic tumor cells is stimulated at least tenfold by low doses (25--300 microgram/mouse/day) of RA while high doses suppress CMC induction. RA is shown to be a specific adjuvant for the induction of cytotoxic thymus-derived lymphocytes (T cells) and not a general T cell mitogen or adjuvant. It does not enhance the proliferative response in the mixed lymphocyte culture nor does it stimulate lymphocyte proliferation in response to the mitogens concanavalin A and phytohemagglutinin. The induction of cooperating T cells and the delayed-type hypersensitivity reaction are also not stimulated by RA. In contrast to the reported stimulatory effects of retinyl palmitate and retinyl acetate, RA does not stimulate the humoral response to erythrocytes. The strong adjuvant effects that RA has on the induction of CMC at low doses may be responsible for its anti-tumor activity.     

Natural zeolite clinoptilolite: new adjuvant in anticancer therapy

Natural silicate materials, including zeolite clinoptilolite, have been shown to exhibit diverse biological activities and have been used successfully as a vaccine adjuvant and for the treatment of diarrhea. We report a novel use of finely ground clinoptilolite as a potential adjuvant in anticancer therapy. Clinoptilolite treatment of mice and dogs suffering from a variety of tumor types led to improvement in the overall health status, prolongation of life-span, and decrease in tumors size. Local application of clinoptilolite to skin cancers of dogs effectively reduced tumor formation and growth. In addition, toxicology studies on mice and rats demonstrated that the treatment does not have negative effects. In vitro tissue culture studies showed that finely ground clinoptilolite inhibits protein kinase B (c-Akt), induces expression of p21WAF1/CIP1 and p27KIP1 tumor suppressor proteins, and blocks cell growth in several cancer cell lines. These data indicate that clinoptilolite treatment might affect cancer growth by attenuating survival signals and inducing tumor suppressor genes in treated cells.     

Adjuvant activities of quinonyl-N-acetyl muramyl dipeptides in mice and guinea pigs.

The adjuvant and tumor-suppressive activities of the quinonyl [2,3-dimethoxy-5-methyl-6-(9'-carboxynonyl)-1,4-benzoquinone (QS-10)] derivatives of N-acetyl muramyl dipeptides were examined. N-Acetyl muramyl-L-valyl-D-isoglutamine (MurNac-L-Val-D-isoGln), QS-10-MurNAc-L-Val-D-isoGln, and their methyl esters were shown to have potent adjuvant activity on the induction of delayed-type hypersensitivity to monoazobenzenarsonate-N-acetyl-L-tyrosine in guinea pigs and on the primary immune response against sheep erythrocytes in vitro; however, only QS-10-MurNAc-L-Val-D-isoGln methyl ester, i.e., QS-10-MurNAc-L-Val-D-Glu(OCH3)NH2 (quinonyl-MDP-66), was shown to be an active adjuvant for the induction of allogeneic killer T cells in mice and the suppression of tumor growth in syngeneic mice when it was administered as a suspension in phosphate-buffered saline. The effectiveness of the chain length of the quinonyl moiety in quinonyl-MDP-66 and the replacement of the L-valine residue with L-serine or L-threonine were also examined in comparison with the adjuvant and tumor-suppressive activities of quinonyl-MDP-66.     

Enhanced antitumor effect of dendritic cell based immunotherapy after intratumoral injection of radionuclide Ho-166 against B16 melanoma

Internal radiotherapy with the intratumoral injection of the beta-emitting radionuclide, Holmium (Ho)-166, into B16 melanoma resulted in a reduction in size and growth rate; however, complete remission was not always achieved. Therefore, additional dendritic cell (DC) therapy was investigated to determine whether it could improve therapeutic results. Malignant melanoma was induced in mice by inoculating B16F10 cell line subcutaneously. Fifty-four mice were divided into four groups: (1) non-treated (group I, n = 11), (2) treated with Ho-166 (group II, n = 16), (3) treated with immature DCs (group III, n = 8), and (4) treated with immature DCs after Ho-166 injection (group IV, n = 19). Changes in tumor size, survival rates, and immunologic profiles were observed. Nineteen days after Ho-166 or PBS injection, mean tumor sizes in the four groups were 6044 +/- 1046, 1658 +/- 523, 3871 +/- 921, and 444 +/- 167 mm(3), respectively. We observed a significant decrease in tumor size (P < 0.05) and an increase in survival in group IV. When the B16F10 cell line was reinjected into the contralateral backs of survivors, much slower growth was observed in group IV (P < 0.05). Both tumor-specific CTL and natural killer cell activities and the infiltration of inflammatory cells into tumor tissues were found to be elevated in group IV. In addition, strong immune responses as determined by in vitro T cell proliferation, ELISA and ELISPOT assay were induced in group IV. Our results suggest that a combination of internal radiotherapy using Ho-166 and immature DCs could be used either to treat unresectable melanoma or as an adjuvant therapy after surgery.     

Relationships between adjuvant, immunosuppressive, and mitogenic activities of staphylococcal peptidoglycan.

Staphylococcal peptidoglycan (PG) possesses in vivo immunodulating activity and is a B-cell mitogen in mice. The effect of PG on in vitro immune response of mouse splenocytes to sheep erythrocytes (SRBC) was studied, as well as the relationships between in vivo and in vitro adjuvant, immunosuppressive, and mitogenic activities of PG in terms of dose response, time kinetics, and physical state. Particulate PG suppressed in vivo anti-SRBC response when injected in a large dose before or simultaneously with SRBC. A small dose of particulate PG given before or along with the antigen was immunostimulatory. Soluble PG was adjuvant active in both high and low doses when injected before or along with the antigen. Both PG preparations were adjuvant active for mouse splenocytes in vitro immunized with SRBC, but particulate PG was more active. Even high doses of particulate PG were not directly suppressive for the in vitro immune response. Particulate PG was also mitogenic for mouse splenocytes, and the maximum increase in [3H]thymidine incorporation was observed after 2 days of culture. Soluble PG was not mitogenic during the 5-day incubation period. These results indicate that the physical state of PG, its dose, and its time of application are important factors determining its immunomodulating and mitogenic activities, and that by changing them it is possible to dissociate the adjuvant, immunosuppressive, and mitogenic properties of PG.     

灵芝孢子粉对荷HAC肝癌小鼠抗肿瘤的实验性研究

本文通过荧光细胞检测技术、体外细胞毒试验以及肿瘤抑瘤率的测定 ,观察了灵芝孢子粉对荷HAC小鼠T细胞表面分化抗原 ,体外细胞杀伤功能以及肿瘤抑瘤率的影响。结果显示灵芝孢子粉治疗组中总T细胞的百分率 (6 3 4% )高于对照组 (5 6 3% ) ,其中对总T细胞、T辅助细胞的上调较为明显。在对HAC、YAC 1和P815肿瘤细胞的杀伤活性中灵芝孢子粉组的杀伤活性分别为 2 7 3%、 2 3 4%和 2 0 0 % ,高于对照组。灵芝孢子粉组的总抑瘤率为 42 2 %。结果表明灵芝孢子粉是一种能激活和提高特异性 (CTL )和非特异性杀伤细胞 (NK、LAK )的抗肿瘤作用 ,抑制肿瘤细胞的增殖以及调控机体免疫功能的中药。     

咖啡酸锗对小鼠U14瘤的抑制作用及其诱导肿瘤细胞凋亡的机制研究

目的：研究咖啡酸锗对荷瘤U14小鼠的体内抑瘤作用及体外抗肿瘤活性，探讨其抗肿瘤作用机制。方法：观察咖啡酸锗对小鼠U14宫颈癌的抑制率；用MG-P染色和透射电镜的方法观察肿瘤细胞的凋亡情况；流式细胞术(FCM)观察瘤组织的细胞凋亡率并分析细胞周期；免疫组化方法观察肿瘤组织中Bax和Bcl-2蛋白表达情况；MTT法评价咖啡酸锗体外抑制U14肿瘤细胞活性。结果：咖啡酸锗低、中、高剂量组对宫颈癌U14的抑瘤率分别为38.50％、47.17％和64.04％（P<0.01）。MG-P染色及电镜观察可见，咖啡酸锗治疗组出现较多的凋亡细胞（P<0.05），可见典型的细胞凋亡的形态学特征。流式细胞术检测表明咖啡酸锗能诱导U14肿瘤细胞凋亡，在G₀-G₁前出现1个明显的凋亡峰，细胞被阻滞在S期。咖啡酸锗处理后肿瘤组织中Bcl-2蛋白表达下调，Bax蛋白表达上调。咖啡酸锗对体外培养的U14细胞增殖均有一定程度的抑制作用，48 h的IC₅₀值为48.57 mg/L。结论：咖啡酸锗在体内、外均能有效抑制小鼠U14瘤细胞的增殖，并诱导肿瘤细胞凋亡。咖啡酸锗上调U14细胞中Bax蛋白的表达，下调Bcl-2蛋白的表达，进而促进肿瘤细胞凋亡，这可能是其发挥抗肿瘤作用的机制之一。     

Adjuvant activity of mycobacterial fractions: adjuvant activity of synthetic N-acetylmuramyl-dipeptide and the related compounds.

Immunological activity of synthetic cell wall peptidoglycan subunits was examined in guinea pigs and mice. It was concluded that the minimal adjuvant-active subunit of cell wall peptidoglycan for the induction of delayed-type hypersensitivity to monoazobenzenearsonate-N-acetyl-L-tyrosine and for circulating-antibody formation to bacterial alpha-amylase and the thymus-independent antigen DNP-Ficoll was N-acetylmuramyldipeptide, MurNAc-L-Ala-D-isoGln. N-acetylmuramyldipeptide and 6-O-stearoyl-N-acetylmuramyldipeptide showed no adjuvant activity in the generation of cell-mediated cytotoxic effector cells in the spleens of C57Bl/6J mice after in vivo immunization with the allogeneic antigen mastocytoma P815-X2 cells, but N-acetylmuramyldipeptide showed adjuvant activity after in vitro sensitization of C57Bl/6J mouse spleen cells to the alloantigen mitomycin C-treated DBA/2 mouse spleen cells. It was also shown that 6-O-stearoylation of N-acetylmuramylpeptide could not potentiate the adjuvant activity of N-acetylmuramyldipeptide. Mitogenic and antitumor activities were not observed in either N-acetylmuramyldipeptide or 6-O-stearoyl-N-acetylmuramyldipeptide in mouse systems.     

Comparison of Peritoneal Macrophages from Germfree and Conventional Mice

Morphology, lysosomal enzyme activities, and phagocytosis via immunological receptors were tested in peritoneal macrophages from germfree and conventional mice. Nonstimulated macrophages from germfree mice showed less spreading and were more easily detached when seeded on glass than conventional macrophages. The activities of the lysosomal acid phosphatase and cathepsin D were similar in the two cell groups, whereas beta-glucuronidase showed higher activity in macrophages from germfree mice. F(c) receptor-mediated phagocytosis of opsonized sheep erythrocytes was equally effective in germfree and conventional macrophages, and both cell types attached but did not internalize erythrocytes via the C(3)b receptor. Intraperitoneal injections of mineral oil caused a significantly higher influx of macrophages in conventional mice than in germfree mice, whereas the influx of polymorphonuclear cells was enhanced in both animals. Stimulation in vivo with oil or Escherichia coli endotoxin increased cell size, spreading ability, membrane ruffling, and lysosomal enzyme activities in macrophages from both conventional and germfree mice. The Fc-mediated phagocytosis was not influenced by stimulation, whereas the capacity to internalize via C(3)b receptor was triggered in macrophages from conventional mice, but not in corresponding cells from germfree mice. Similar results were obtained after stimulation with endotoxin in vitro. Culture in fetal calf serum for 72 h caused intracellular rises in all three enzyme activities tested in macrophages from conventional mice, whereas only the activity of acid phosphatase was increased in macrophages from germfree mice. Stimulation with zymosan in vitro caused selective release of lysosomal enzyme activity in macrophages from both animal groups. We conclude that peritoneal macrophages from germfree mice share several properties with cells from conventional mice, however, unstimulated beta-glucuronidase activity was increased, whereas spreading on glass, chemotactic response, in vitro induction of lysosomal enzymes, and the capacity to internalize via the C(3)b receptor after stimulation were reduced or absent.     

Antitumor activity of expanded human tumor-infiltrating gammadelta T lymphocytes

BACKGROUND: The objective of this study was to investigate the antitumor activity of selectively expanded gammadelta T cells in tumor-infiltrating lymphocytes (gammadeltaTILs) or tumor ascites lymphocytes (gammadeltaTALs) from patients with colorectal and ovarian epithelial carcinoma (OEC) in vitro and in vivo. METHODS: gammadeltaTILs/TALs were expanded by the solid-phase antibody method; their cytolytic and proliferative activities in vitro were detected by the MTT method and 3H-TdR incorporation and their effect in vivo was evaluated by the nude mice model. RESULTS: Expanded gammadeltaTILs from colorectal tumors demonstrated marked cytotoxicities to allogeneic human colon adenocarcinoma HR8348 and lymphoma Daudi cells, as well as xenogeneic murine thymoma EL-4 cell lines. Cytokines, including IL-2, IL-4, IL-12, IL-15, TNF-alpha and INF-gamma, could promote the cytotoxicities of gammadeltaTILs to tumor cells, whereas IL-10, GM-CSF and TFG-beta had no effect on such killing activities. Rested gammadeltaTILs could proliferate strongly in response to mitomycin C-treated Daudi and EL-4 tumor cells, but not to HR8348 tumor cells, suggesting that the latter might possess only cytotoxicity-related antigen recognized by gammadeltaTILs. Either alphabetaTILs or gammadeltaTILs from patients with OEC displayed cytotoxicities to allogeneic or autologous OEC cell lines at a similar strength in vitro. Transferring gammadeltaTILs into Daudi cell-bearing BALB/c nude mice with an injection of IL-2 was able to maintain a high survival rate of the mice for 30 days, when compared with mice treated with alphabetaTILs or without any treatment (p < 0.05). Without coinjection of IL-2, after 3 months of Daudi tumor inoculation, a high survival rate was observed in gammadeltaTIL-treated mice. Similarly, adoptive gammadeltaTALs from the ascites of patients with OEC transferred into nude mice displayed a stronger antitumor response to OEC SKOV3 cells than alphabetaTALs in vivo. Tumor volumes in gammadeltaTAL-treated mice were smaller than in alphabetaTAL-treated or non-TAL-treated mice within the period from day 23 to day 50 after tumor inoculation (p < 0.05). Fifty days after SKOV3 tumor inoculation, a decreasing trend of carcinogenic rate was observed in gammadeltaTAL-treated nude mice. CONCLUSION: Taken together, our results suggest that gammadeltaT cells could be a new candidate for adoptive immunotherapy in the future treatment of patients with cancer.     

The dissociation of adjuvant properties of mycobacterial components from mitogenicity, and from the ability to induce the release of mediators from macrophages.

Twelve preparations from mycobacterial cell walls and culture supernatant fluids were tested for their ability to activate lymphocytes from Balb/c or Nu/Nu mice, and to increase the release of mediators from macrophages in vitro. The peptidoglycolipids (wax D) were B-cell mitogens and induced plaque-forming cells. These properties were lost if the glycopeptide component was removed, leaving the pure lipid, mycolic acid. Neither the glycopeptide fractions, with well-documented adjuvant properties, nor mycobacterial polysacchardie II-activated B cells. Only intact peptidoglycolipid showed synergy with the mitogenic effect of phytohaemagglutinin (PHA) on thymocytes from Balb/c mice. The effect was much smaller than with E. coli lipopolysacharide (LPS) or dextran sulphate. The peptidoglycolipid also enhanced the release of factors from macrophages able to modify the response of Balb/c thymus cells to PHA. In this respect it resembled E. coli LPS. Adjuvant active glycopeptides did not share this property.     

Anti-metastatic properties of RGD-peptidomimetic agents S137 and S247

Integrins expressed on endothelial cells modulate cell migration and survival during angiogenesis. Integrins expressed on carcinoma cells potentiate metastasis by facilitating invasion and movement across blood vessels. We describe the activities of two synthetic low-molecular-weight peptidomimetics of the ligand amino acid sequence arg-gly-asp (RGD) in integrin-based functional assays in vitro. We also evaluate efficacy and potential mechanisms of action in models of both spontaneous and experimental metastasis. Broad-spectrum potency against the family of alpha v subunit-containing integrins was observed, with significantly less potency against alpha5beta1 and alpha(IIb)beta3. Both endothelial and tumor cell migration mediated by alpha(v)beta3 was inhibited, whereas proliferation of endothelial cells but not tumor cells was diminished. Continuous infusion of compound by minipumps or oral administration twice daily significantly reduced metastatic tumor burden in the lungs of mice despite no reduction in growth of 435/HAL primary tumors, and only a slight reduction in tumor cells detected in circulating blood. Delaying treatment in this model until after extensive dissemination of tumor cells to the lungs had occurred, and after primary tumor resection, still produced significant efficacy. Conversely, administration of the agent for only the first 18 h after tumor-cell inoculation into the tail vein also resulted in decreased metastases observed after several weeks. These data suggest these compounds or their relatives have potential to interfere with both early and late steps of metastasis involving tumor and endothelial cell functions. Furthermore, the metastatic process can be effectively inhibited independently of primary tumor growth using integrin antagonists.     

Relaxin promotes differentiation of human breast cancer cells MCF-7 transplanted into nude mice

Previous studies showed that the hormone relaxin acts on human breast cancer MCF-7 cells in vitro by modulating cell proliferation and promoting cell differentiation toward a duct epithelial phenotype. The present study was designed to investigate whether relaxin retains these properties when acting in vivo on MCF-7 cell tumors developed in athymic nude mice. Mice bearing MCF-7 cell tumors transplanted under the mammary fat pad and estrogenized to sustain tumor growth were treated systemically with relaxin (10 μg/day) for 19 days. Vehicle-treated mice were used as controls. Thirty days later, the mice were sacrificed and tumor fragments were analyzed by light and electron microscopy and immunocytochemistry. Measurements of tumor volume were recorded weekly for the overall experimental period. The results obtained indicate that relaxin treatment promotes differentiation of tumor cells towards both myoepithelial-like and epithelial-like cells, as judged by the ultrastructural features of the cells and by the increased expression of smooth muscle actin and cadherins. Measurements of tumor size and of the number of cycling cells show that relaxin, at the doses and times of exposure used in this study, does not significantly influence tumor growth and cell proliferation. Received: 3 March 1999 / Accepted: 28 May 1999     

Granzymes are essential for natural killer cell-mediated and perf-facilitated tumor control

Studies with perforin-deficient mice firmly established perforin as a key element in cytotoxic T cell (CTL) / natural killer (NK) cell-mediated tumor control but did not reveal the role of granzyme (gzm) A and B. A contribution of gzm in these processes was indicated by earlier in vitro experiments employing purified effector molecules demonstrated that tumor cell apoptosis and death only occurred in the presence of both, perf and gzm. However, recent work using mice deficient in either gzmA, gzmB or both gzm suggested that only perf but neither of the two gzm are critical for tumor surveillance by CTL or NK cells. In light of the conflicting results we have re-investigated this issue by analyzing the potential of mice deficient in one or more component(s) of the exocytosis pathway to control NK-sensitive syngeneic MHC class I-defective RMA-S tumor cells in vivo. Our results show that in contrast to wild-type mice, mice deficient for both gzm exhibit an uncontrolled tumor growth with a time kinetic similar to that of perforin-deficient mice. Together with the finding that a defect of mice in either gzmA or gzmB alone also leads to an increased susceptibility to tumor growth, at least to a certain extent when compared to wild-type mice, the data clearly indicate that a concerted action of perforin and the two gzm is mandatory for optimal NK cell-mediated tumor control in vivo. Most notably, the in vivo potential of the respective NK cell populations was only reflected by their nucleolytic, but not their cytolytic activities in vitro.     

Effect of pH on the production of the Kanagawa hemolysin by Vibrio parahaemolyticus.

Cord factor--a mixture of 6,6'-diesters of alpha, alpha-D-trehalose with natural mycolic acids--which is purified from mycobacteria and other microorganisms, is known to have adjuvant activity as well as to enhance nonspecific resistance to infections and tumor development. In this work, trehalose 6,6'-dimycolate (TDM) was found to induce proliferative responses in rat thymus and lymph node cells. With the thymus cells, TDM responses were greater after removal of the adherent cell subpopulation. Consistent with this observation was the finding that addition of phagocytic cells purified from peritoneal or lymph node cell suspensions to nonadherent thymocytes abrogated the response of thymocytes to TDM. With the lymph node cells, the presence or removal of adherent cells had no major consequence on the TDM-induced proliferative response, since similar increases in deoxyribonucleic acid synthesis were observed with unfractionated and nonadherent cells. The difference between the sensitivities of thymus cells and lymph node cells to regulation by adherent cells indicated the existence of more than one type of TDM responder cell in rats. TDM also displayed marked stimulatory activity on thymus and lymph node cells from germ-free rats, ruling out the possibility that TDM might have triggered a specific, secondary, in vitro immune response. Expansion of a selected cell population(s) triggered by TDM may be involved in the manifestation of adjuvant activity and possibly other immunological properties of cord factor.     

Role of cellular density,in vitro,in anti-tumor activity of CFA-treated and immunized cells

Incorporation of tritiated deoxythymidine (³HdT) into DNA was used to measure growth, in vitro, of P815 tumor cells admixed with spleen and peritoneal effector cells. At a high tumor cell density (1×10⁵ cells per dish), using anti-theta and anti-macrophage sera, T-cells and macrophages from the peritoneum of immunized mice could be identified as cells possessing anti-tumor activity. A nonspecific inhibition by normal effector cells, which occurred at the high tumor cell density, did not occur at a lower tumor cell density (1×10⁴ cells per dish). Therefore, the effects of immunization and Freund's adjuvant treatment on the anti-tumor activity of effector cells were determined more accurately when normal cells were no longer inhibitory. Thus, experimental variables dealing with cellular density (cells/mm² of the culture vessel surface) and effector: tumor cell ratios play an important role in the anti-proliferative capacity of effector cells.     

Activation of cytotoxic T cells and effector cells in experimental autoimmune thyroiditis by shared determinants of mouse and human thyroglobulins

Previous studies have shown that T cells from genetically susceptible mice developing experimental autoimmune thyroiditis (EAT) proliferate in response to restimulation with mouse thyroglobulin (MTg) in vitro and differentiate into cells cytotoxic for syngeneic thyroid monolayers. To examine further the effector cells involved in pathogenesis and the determinants on MTg responsible for their activation, spleen cells (SC) and lymph node cells (LNC) from mice immunized with MTg or human (H) Tg, and adjuvant (complete Freund's adjuvant (CFA) or lipopolysaccharide (LPS] were cultured in vitro with MTg or HTg. Control cultures were incubated with concanavalin A (Con A) or purified protein derivative (PPD). The in vitro-activated cells which proliferated in response to MTg, HTg, or Con A adoptively transferred thyroiditis to normal recipients, whereas cells transferred directly without in vitro culture were very ineffective. The capacity to transfer EAT was abrogated by irradiation (1500 R), and SC from CFA-immunized control mice which responded in vitro to PPD stimulation did not transfer thyroiditis. The serum titers of MTg autoantibodies were uniformly low and were not correlated with severity of disease. The localization of EAT-effector (precursor) cells depended upon the site of immunization; they were found in the spleens after inguinal (subcutaneous) or systemic (intravenous) immunizations, but were present in the popliteal lymph nodes after hind footpad injections. Both homologous MTg and heterologous HTg functioned as in vivo sensitizing antigen and in vitro activating antigen for each other; such cultured cells transferred thyroiditis in vivo and became cytotoxic for thyroid monolayers in vitro. These findings show that shared determinants are autoantigenic and thyroiditogenic, and support the hypothesis that EAT-effector cells responsible for initiating thyroid damage include cytotoxic cells.     

Delayed hypersensitivity to soluble antigens in mice. II. Analysis in vitro.

Delayed hypersensitivity to a soluble protein has been analyzed in vitro with lymph node cells from mice. Antigen-dependent cytotoxicity against innocent bystander cells, and incorporation of tritiated thymidine have been used to monitor the response to a subcutaneous tail injection of egg albumin (OVA) in complete Freund's adjuvant. Sensitized lymph node cells from mice with positive 24 h ear tests killed A9 cells in the presence of antigen. This antigen-specific, T cell-mediated cytotoxicity was observed within 4 days of sensitization and still apparent at 7 months. Reactivity to OVA, assessed as an increase in DNA synthesis in the presence of antigen, was also T cell dependent and exhibited similar sensitization kinetics and dose requirements. Both microtechniques require as few as 10(5) lymphocytes and are readily adaptable to the study of delayed hypersensitivity to any soluble protein in mice.     

抗粘附肽YIGSR的衍生物对Lewis肺癌侵袭、转移能力的抑制作用

采用高转移肿瘤细胞对基底膜成分的体外粘附、侵袭模型和Lewis肺癌细胞自发肺转移模型 ,研究了YIGSR均叉、杂叉聚合肽的抗肿瘤侵袭、转移活性。实验结果 ,RGD和YIGSR的杂叉肽和YIGSR的均叉肽对PG细胞较对照的YIGSR肽表现了更明显的粘附抑制作用 ,并降低了PG细胞的体外侵袭能力 ,降低了移值Lewis肺癌细胞肺转移小鼠的肺重量或肺转移瘤结节数 ,但对小鼠原发部位移植瘤重量无明显影响 ;YIGSR聚合肽的以上作用有一定的剂量依赖性。     

Individual cell-based models of tumor-environment interactions: Multiple effects of CD97 on tumor invasion

The presence of scattered tumor cells at the invading front of several carcinomas has clinical significance. These cells differ in their protein expression from cells in central tumor regions as recently shown for the EGF-TM7 receptor CD97. To understand the impact of such heterogeneity on tumor invasion, we investigated tumor cells with modified CD97 expression in vitro and in vivo. Applying an individual cell-based computer model approach, we linked specific cell properties of these cells to tumor invasion characteristics. CD97 overexpression promoted tumor growth in scid mice, stimulated single cell motility, increased proteolytic activity of matrix metalloproteinases, and secretion of chemokines in vitro in an isoform-specific manner. We demonstrated by computer simulation studies that these effects of CD97 can increase the invasion capacity of tumors. Furthermore, they can cause the appearance of scattered tumor cells at the invasion front. We identified local tumor environment interactions as triggers of these multiple capabilities. Experimentally, our simulation results are supported by the finding that CD97 expression in tumor cells is regulated by their environment. Our combined experimental-theoretical analysis provides novel insight to how variations of individual cell properties can be linked to individual patterns of tumor cell invasion.