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Biomedical subjects

K Okuno

Publications and source records attributed to K Okuno.

At least 73 records · Page 4Linked to original sources
PubMed1993

Successful in vivo generation of canine lymphokine-activated killer cells by continuous recombinant interleukin-2 infusion through the splenic artery.

We studied the efficacy of infusing human recombinant interleukin-2 (IL-2) through the splenic artery for generation of lynphokine activated killer (LAK) cells in vivo in a canine system. Catheters were inserted into the splenic artery, portal vein and inferior vena cava (IVC) in Beagle dogs. IL-2 was administered continuously through either the splenic artery or IVC by portable infusion pump and the cytotoxic activity of portal vein blood lymphocytes (PVBL) and peripheral blood lymphocytes (PBL) against canine osteosarcoma D-17 target cells was monitored. Following administration low-dose IL-2 (8 x 10(5) IU/day) for 6 days through the splenic artery, LAK precursor cells were present, but not following administration intravenously. Interestingly, when a high dose of IL-2 (4 x 10(6) IU/day on days 1-6 and 13-18) was administered through the splenic artery, strong cytotoxicity was detected in PVBL and PBL without subsequent culture in vitro with IL-2, suggesting that an infusion rate of 4 x 10(6) IU/day IL-2 may be sufficient for generation of LAK cells in vivo. These results suggest that continuous infusion of IL-2 through the splenic artery can generate LAK cells more easily and may prove especially useful for the immunotherapy of hepatic micrometastasis.

Animals↗
PubMed1993

Enhanced activity against syngeneic murine tumors by intrasplenic injection of recombinant interleukin-2 (IL-2) and interleukin-1 (IL-1).

The antitumor activity of Interleukin-1 (IL-1), was assessed against the murine adenocarcinoma colon 26 tumor model in combination with Interleukin-2 (IL-2). Colon 26 tumor cells were inoculated on the back of syngeneic BALB/c mice. Fourteen days after inoculation, when the tumor nodule reached approximately 10 mm in diameter, tumor nodules were resected and Hank's solution, IL-2, IL-1, or IL-2 plus IL-1 were injected directly into the mouse spleen. One week after treatment, potent natural killer (NK) and enhanced lymphokine activated killer (LAK) cell activities were seen in the splenocytes treated by the combination of IL-2 plus IL-1. Furthermore the combination treatment by IL-2 plus IL-1 resulted in a significantly prolonged survival. Phenotypic analysis showed an increased number of percent positive cells expressing asialo GM 1 and IL-2 receptor after treatment with IL-2 plus IL-1. A possible role of IL-1 in augmentation of IL-2 dependent antitumor activity in vivo is discussed.

Adenocarcinoma↗
PubMed1992

Clinical trials of intrasplenic arterial infusion of interleukin-2 (IS-IL-2) to patients with advanced cancer.

We tried a infusion of interleukin-2 (IL-2) of a relatively low dose via an intrasplenic arterial catheter connected to a chronometric infusion (IS-IL-2). Eighteen patients of colorectal cancer with metastases to the liver or lung or of unresectable hepatoma received a 24 hour continuous infusion with low dose recombinant of IL-2 (mainly 8 x 10(5) JRU/day) for 25-40 days. All patients tolerated this protocol of the therapy and the main toxic effects were fever and general fatigue. Such serious toxicity as previously reported by high dose IL-2 therapy was not observed. Data of hepatic and renal functions were normal. IS-IL-2 therapy induced a high incidence of eosinophilia (12/18) and thrombocythemia (12/18). Peripheral natural killer (NK) and LAK activities were augmented in all patients and total white blood cell counts were increased during IS-IL-2 therapy. An increase in IL-2 receptor expression of peripheral blood mononuclear cells and significant rises in numbers of Leu11 (CD16)+, OKM1(CD11)+ and OKIa1(HLA-DR)+ were observed. Of 18 patients 12 were evaluable for their response to therapy. Partial response (PR) was observed in one unresectable hepatoma and 11 demonstrated no change (NC) or progressive disease (PD). Six patients were not evaluable because of additional therapy (3 cases) or decreasing tumor cell markers having no measurable lesions (3 cases). Three patients of colorectal cancer from an unresectable group were presumed to have micrometastases to the liver as suggested by an elevated serum CEA level. After receiving IS-IL-2 therapy they demonstrated a decrease in the serum CEA level for more than 3 years after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Augmentation of human lymphokine-activated killer cell activity in splenic lymphocytes by the combination of low-dose interleukin 2 plus interleukin 3.

The effect of interleukin 3 (IL-3) on lymphokine-activated killer cell (LAK) generation in splenic lymphocytes was examined in patients with gastric cancer or idiopathic thrombocytopenic purpura (ITP). IL-3 alone did not induce any significant LAK activity from splenic lymphocytes. However, IL-3 addition to the culture with low-dose IL-2 significantly augmented the activity of LAK cells. Spleen cells precultured with IL-3 for 2 days and then added to IL-2 became more potent LAK cells than the spleen cells cultured with the same doses of IL-3 plus IL-2. Phenotypic analysis using flow cytometry demonstrated that IL-2 alone increased in cells expressing CD2+, -11+, and -16+ cells, whereas IL-3 plus IL-2 induced the expansion of CD3+ and CD8+ cells in addition to CD2+, -11+, and -16+ cells. These results suggest that IL-3 plus IL-2 phenotypically induces not only natural killer-like LAK cells (CD2+, -11+, and -16+) but T cell-like LAK cells (CD3+ and -8+). We are now investigating the characteristics of immature T cell populations in the spleen responsive to IL-3 using T-cell receptor antibody.

Antigens, CD↗
PubMed1991

CD4+ T cell clones specific for the human p97 melanoma-associated antigen can eradicate pulmonary metastases from a murine tumor expressing the p97 antigen.

p97 is a human tumor-associated Ag present on most melanoma cells that represents a possible target for immunologic attack. To evaluate the capacity of T cells reactive with this protein to promote elimination of melanoma cells expressing p97, a murine model was developed by transfecting a C3H/HeN melanoma with the p97 cDNA, generating p97-specific CD4+ T cells by in vivo immunization of C3H/HeN mice with a vaccinia/p97 recombinant virus followed by in vitro cloning with soluble p97 protein, and determining whether these CD4+ T cells could mediate rejection of pulmonary metastases. Characterization of the T cell clones demonstrated the presence of both I-Ak and I-Ek-restricted clones, although the majority of clones recognized p97 in the context of I-Ek. Analysis of clonal specificity using truncated p97 proteins revealed that at least three epitopes were immunogenic, and further studies with overlapping 15-amino acid peptides from a region of the p97 molecule defined by these truncated proteins identified an immunodominant epitope responsible for the majority of the I-Ek response. The T cell clones were not capable of directly recognizing the p97-expressing melanoma cells but responded to the tumor if syngeneic APC were present to process the tumor-derived p97 Ag. The therapeutic efficacy of these CD4+ T cell clones was evaluated in an adoptive therapy model in which mice bearing metastatic pulmonary lesions were treated by i.v. administration of the p97-specific cells. Despite the inability of the CD4+ clones to directly respond to or lyse the tumor cells, the clones were effective in promoting tumor eradication. In vitro studies demonstrated that this may have reflected secretion of lymphokines that activated macrophages to lyse the tumor. The results suggest that noncytolytic p97-specific CD4+ T cell clones can be effective in therapy of pulmonary melanoma metastases. Moreover, if human T cells reactive with the p97 protein could be generated, the expression of this tumor-associated Ag in melanoma cells might be adequate for such T cells to mediate a therapeutic antitumor response.

Animals↗
PubMed1991

The lymphoid cell populations required for induction of tolerance of different subsets of alloantigen-reactive T cells.

Previous studies have demonstrated that i.v. presensitization of C57BL/6 (B6) mice with class I H-2-disparate B6-C-H-2bml (bml) spleen cells induced potent suppression of anti-bml CD8+ T cell-mediated responses in vitro as well as suppression of the allograft response. The present study analyzes the population of donor bml cells required for suppression of the generation of the cellular subsets involved in the in vitro and in vivo immune responses. Anti-bml CD8+ helper T cell (proliferative/IL-2-producing) activities were almost completely eliminated by i.v. inoculation of bml whole blood or various (T or B cell) fractions of spleen cells. However, anti-bml CD8+ cytotoxic T lymphocyte capacity was significantly reduced by i.v. sensitization with bml T cell-containing, but not with T cell-depleted splenic fractions. In B6 mice receiving bml skin grafts following i.v. sensitization with T-depleted bml spleen cells, marginal Th activity was induced. However, the CTL response was equal to that observed in unsensitized mice, and allograft survival was not prolonged. Prolongation of bml graft survival was achieved by i.v. presensitization with bml T cell fraction, indicating that bml T cells were a requirement for suppression of graft rejection in the B6-bml combination. In contrast, in the B6-C-H-2bml2 (bml2) combination in which CD4+ T cells are responding to bml2 alloantigens, only the B cell fraction was capable of prolonging bm12 graft survival. These results indicate that functionally and phenotypically different subsets of alloantigen-reactive T cells are rendered unresponsive by i.v. presensitization with distinct fractions of donor lymphoid cells.

Animals↗
PubMed1991

[Splenic or hepatic arterial injections of interleukin-2 with chemotherapeutic agents for hepatic metastases].

Splenic or hepatic arterial injections of interleukin-2 (IL-2) with chemotherapeutic agents were performed in colorectal cancer patients with metastasis of the liver. LAK/NK activities in PBL from the patients receiving IL-2 plus cyclophosphamide (CY) splenic infusion were much potent than those of the patients receiving IL-2 alone. Twelve patients were treated with hepatic arterial infusions of IL-2 and mitomycin C (MMC)/5 fluorouracil (5FU). Ten patients were evaluable and remaining 2 cases were not evaluable because of having no measurable lesion; prophylactic infusion for occult metastasis after hepatectomy. Six out of 10 had a complete or partial response (60%), especially all patients receiving 6 months and more (3 cases) had a complete response (100%) and CEA level decreased to normal range. Lymphocyte phenotype study showed notable decrease in CD8+, 16+, 57+ cells and increase in CD4+ cells (elevation of 4/8 ratio) during the therapy. NK activity was closely related to the percentage of CD 16+, 57+ cells in peripheral blood lymphocytes (PBL). These results might be reflected the dramatic accumulation of cytotoxic cells to the liver by the direct activation of hepatic sinusoidal endothelium due to IL-2 perfusion.

Aged↗
PubMed1990

[Immunomodulating effect of intratumoral (IT) injection of biological response modifiers (BRM) on tumor-bearing hosts].

Preoperative endoscopic intratumoral injection (IT) of biological response modifiers (BRM), such as OK432, a compound composed of attenuated Streptococcus pyogens, in gastric cancer patients has been tried and this method has been improving the prognosis compared to surgical resection only. We tried to clarify this mechanism using experimental mouse system and demonstrated here the preoperative IT of OK432 significantly prolonged the survival and induced the tumor-specific cytotoxic T lymphocytes (CTL) in the spleen. By contrast, tumor necrosis factor (TNF) IT failed to prolong the survival and to induce specific CTL response, although it reduced primary tumor size significantly. To analyze why OK432 IT induce the systemic CTL response, viable tumor cells and infiltrating dish-adherent cells from the OK432 injected tumor mass were harvested and examined the class I and class II antigen expression by flow cytometer. Class I and class II antigen expression of the tumor cells remained unchanged, however, the class II positive dish-adherent cells markedly increased by OK432 pretreatment. As same in these results, histological finding in gastric cancer specimen has shown prominent increase of Langerhans cells, possessing potent antigen-presenting function and positive class II antigen, by OK432 pretreatment. Taken together, these findings strongly suggest that the increased class II positive antigen-presenting cells (APC) activity by OK432 IT augment the CTL response via cascade reaction and finally, resulted in anti-tumor efficacy in vivo.

Animals↗
PubMed1990

[Induction of lymphokine activated killer (LAK) and prolongation of its activity by intrasplenic injection of interleukin 2 (IL-2) in combination with tumor necrosis factor (TNF)].

We have so far investigated the method to induce LAK cells efficiently within the body by direct intrasplenic injection of Interleukin 2 (IL-2) in tumor bearing mice. In this study we used IL-2 in combination with rTNF in an attempt to induce effectively much stronger LAK cells and found that the combined use resulted in not only enhancement but also significant prolongation of LAK activity. Furthermore, the combined use also yielded in vivo effect, that is prolongation of the mouse survival. This study suggests that the combined use of IL-2 and TNF may promise more effective induction of LAK cells in the organism with much smaller doses of IL-2. The combined use may be helpful to improve the treatment regimen by intra arterial injection of IL-2 that we have so far conducted, possibly leading to a higher response rate in clinical setting.

Animals↗
PubMed1989

Identification of a unique T cell-derived lymphokine that primes macrophages for tumor cytotoxicity.

Macrophage activation factor (MAF) activity, assessed by the ability to activate macrophages (MO) to lyse RBL--a TNF-resistant, retrovirally transformed, tumor target--was detected in the PHA-stimulated supernatant (Sup) of LBRM, a murine T cell line. LBRM Sup provided a priming signal to MO, but required the subsequent addition of small amounts of LPS for the expression of tumor cytotoxicity. The identity of the lymphokine responsible for this MAF activity was investigated. IFN-gamma, the only previously characterized lymphokine capable of priming MO for tumor cytotoxicity, did have MAF activity in the assay, but IFN-gamma could not be detected by ELISA in LBRM Sup, and LBRM-derived mRNA lacked detectable message for IFN-gamma. Moreover, anti-IFN-gamma failed to inhibit the MAF activity of LBRM Sup, suggesting that the presence of small, undetectable amounts of IFN-gamma were neither responsible nor required for LBRM MAF activity. LBRM MAF activity appeared distinct from the other previously identified lymphokines produced by LBRM, since granulocyte-macrophage-CSF, IL-2, and IL-3 purified from LBRM Sup were unable to activate MO to lyse RBL. IL-4 and TNF, two lymphokines not known to be produced by LBRM but able to activate MO for cytotoxicity of some tumor targets, were also unable to activate MO for RBL cytotoxicity. LBRM MAF lacked antiviral activity in biologic assays, further distinguishing the lymphokine from IFN-gamma, and had an apparent Mr of 30,000 Da using gel filtration chromatography. Thus, the LBRM T cell line produces a previously undescribed lymphokine that primes MO for tumor cytotoxicity.

Animals↗
PubMed1989

FBL-reactive CD8+ cytotoxic and CD4+ helper T lymphocytes recognize distinct Friend murine leukemia virus-encoded antigens.

Immunization of C57BL/6 (B6) mice with FBL, a Friend murine leukemia virus (F-MuLV), induces both tumor-specific cytolytic CD8+ (CTL) and lymphokine-producing CD4+ Th that are effective in adoptive therapy of B6 mice bearing disseminated FBL leukemia. The current study evaluated the F-MuLV antigenic determinants expressed on FBL that are recognized by FBL-reactive CD8+ and CD4+ T cells. To identify the specificity of the FBL-reactive CD8+ CTL, Fisher rat embryo fibroblast (FRE) cells transfected with plasmids encoding F-MuLV gag or envelope (env) gene products plus the class I-restricting element Db were utilized. FBL-reactive CTL recognized FRE target cells transfected with the F-MuLV gag-encoded gene products, but failed to recognize targets expressing F-MuLV env. Attempts to generate env-specific CD8+ CTL by immunization with a recombinant vaccinia virus containing an inserted F-MuLV env gene were unsuccessful, despite the generation of a cytolytic response to vaccinia epitopes, implying that B6 mice fail to generate CD8+ CTL to env determinants. By contrast, CD4+ Th clones recognized FRE target cells transfected with env and not gag genes, and immunization with the recombinant vaccinia virus induced an env-specific CD4+ T cell response. These data show that in a Friend retrovirus-induced tumor model in which tumor rejection can be mediated by either CTL or Th, antigens derived from discrete retroviral proteins are predominantly responsible for activation of each T cell subset.

Animals↗