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PubMed1991

Tissue distribution of recombinant mouse interferon-gamma and recombinant human interferon-gamma in mice, rats, hamsters, and monkeys.

Homologous (mouse) and heterologous (human) recombinant interferon-gamma (IFN-gamma) interferons were injected intravenously into C57BL/6 mice. After 5 min, the greatest proportion of the human IFN was found in the liver, whereas no mouse IFN was detected in the liver at this time or later. Similar results were found in rats, hamsters, and cynomolgus monkeys. Thus, the tissue distribution of these two recombinant IFN-gamma in the various species is not determined by species specificity but by the physicochemical characteristics of the molecules.

Animals↗
PubMed1997

Initiation of V(D)J recombination in vivo: role of recombination signal sequences in formation of single and paired double-strand breaks.

In V(D)J recombination, double-strand breaks (DSBs) are introduced at recombination signal sequences (RSSs) which consist of three distinct elements: a heptamer, a 12 or 23 nucleotide spacer and a nonamer. Efficient DSB formation requires a 12/23 RSS pair and occurs at both RSS in a temporally coupled fashion (coupled cleavage). It remains unknown which RSS elements are important for coupled cleavage. Furthermore, it has not been established whether some RSS components are critical only for cleavage in cis, with others mainly promoting cleavage in trans at the partner RSS. We investigated these questions by analyzing the effects of RSS mutations on the formation of DSBs in vivo. The abundance of DSBs in cis (at the mutant RSS) and in trans (at the consensus RSS) was determined using an established ligation-mediated PCR assay. We also developed a Southern blotting approach that allows the first direct measurement of dual and single RSS cleavage in vivo. Our results demonstrate that the heptamer, spacer and nonamer elements are all required for coupled cleavage in vivo. These studies also provide evidence for cleavage events involving a single RSS both in mutant substrates and in substrates containing a consensus 12/23 RSS pair.

DNA↗
PubMed1998

Heparin and its derivatives bind to HIV-1 recombinant envelope glycoproteins, rather than to recombinant HIV-1 receptor, CD4.

We have employed a direct radiolabel binding assay to investigate the interaction between3H-heparin and recombinant envelope glycoproteins, rgp120s, derived from several different isolates of HIV-1. Comparable dose-dependent binding is exhibited by rgp120s from isolates IIIB, GB8, MN and SF-2. Under identical experimental conditions the binding of3H-heparin to a recombinant soluble form of the cellular receptor for gp120, CD4, is negligible. The binding of3H-heparin to rgp120 is competed for by excess unlabeled heparin and certain other, but not all, glycosaminoglycan and chemically modified heparins. Of a range of such polysaccharides tested, ability to compete with3H-heparin for binding was strictly correlated with inhibition of HIV-1 replication in vitro. Those possessing potent anti-HIV-1 activity were effective competitors, whereas those having no or little anti-HIV-1 activity were poor competitors. Scatchard analysis indicates that the K d of the interaction between heparin and rgp120 is 10 nM. Binding studies conducted in increasing salt concentrations confirm that the interaction is ionic in nature. Synthetic 33-35 amino acid peptides based on the sequence of the V3 loop of gp120 also bind to heparin with high affinity. V3 loop peptides that are cyclized due to terminal cysteine residues show more selective binding than their uncyclized counterparts. Overall, these data demonstrate further that heparin exerts its anti-HIV-1 activity by binding to the envelope glycoprotein of HIV-1, rather than its cellular receptor, CD4. This study confirms that the V3 loop of gp120 is the site at which heparin exerts its anti-HIV-1 activity. Moreover, it reveals that high affinity binding to heparin is shared by all four rgp120s examined, despite amino acid substitutions within the V3 loop.

Animals↗
PubMed1998

Recombinant luteinizing hormone as a survival and differentiation factor increases oocyte maturation in recombinant follicle stimulating hormone-supplemented mouse preantral follicle culture.

The effects of recombinant luteinizing hormone (rLH) and recombinant follicle stimulating hormone (rFSH) both separately and together were analysed on the in-vitro maturation of a well-defined class of mouse early preantral follicles. Metaphase-II (MII) oocytes were only obtained when rLH or rFSH or a combination of both hormones was added to a standard rich culture medium at constant doses throughout the culture period. Without gonadotrophins only 8% of the follicles reached day 12 of culture. Follicle survival was optimal (between 90 and 100%) when rFSH was used; significantly fewer follicles were kept intact when rLH was added as the only supplement (54%; P < 0.001). Theca cells played a fundamental role in follicle survival when rLH was the only supplement. Presence of rLH significantly influenced the formation of antral-like cavities: on day 12, 59% of follicles cultured with rLH + rFSH had a large cavity, as compared with only 21% in cultures with rFSH only (P < 0.0001). The rHCG stimulated germinal vesicle breakdown rate from the different gonadotrophin-supplemented cultures on day 12 was not significantly different (FSH: 89%; LH: 70%; FSH/LH: 83%). However, addition of rLH to rFSH did significantly improve (P < 0.05) the completion of the first meiotic division up to the MII stage (FSH: 46%; LH: 39%; FSH/LH: 76%). Interfollicle differences in steroid production were very large and depended on the presence of theca cells and on the kind of gonadotrophin supplemented. Without theca cells, oestrogen concentrations in rFSH-supplemented cultures were 100 times lower than their theca-containing counterparts during the entire culture period. From culture day 9 onwards most conditioned media had increased basal progesterone concentrations. This study points up the in-vitro role of LH on the differentiation of follicle-like structures and the oocyte's meiotic maturation and suggests an important role for theca cells in providing modulators of in-vitro gonadotrophin action.

Animals↗
PubMed2001

The effectiveness and safety of recombinant human LH to support follicular development induced by recombinant human FSH in WHO group I anovulation: evidence from a multicentre study in Spain.

BACKGROUND: Until recently, human menopausal gonadotrophin (HMG), a urinary extract containing a fixed combination of LH and FSH, was the only source of exogenous LH for women with hypogonadotrophic hypogonadism undergoing ovulation induction with gonadotrophins. Recombinant human LH (rLH) is now available for clinical use, providing a new treatment option but clinical data on its use are scanty. Therefore, the aim of the present study was to investigate the efficacy and safety of rLH combined with recombinant FSH (rFSH) to induce follicular development and ovulation in World Health Organization (WHO) group I anovulatory women. METHODS: We included in this multicentre study 38 hypogonadotrophic anovulatory (WHO group I) women. Patients received 150 IU/day rFSH and 75 IU/day rLH (with the possibility of dose adjustment) as a single s.c. injection for up to three cycles with a total of 84 treatment cycles. RESULTS: Sufficient follicular growth was observed in 79 (94%) out of 84 initiated cycles. The 75 IU rLH dose was found to be effective in most treatment cycles (94%) and only five cycles in three patients required daily dose increase. Overall, HCG was administered to trigger ovulation in 67 (80%) of the 84 cycles while it was withheld in 12 cycles (14%) due to ovarian hyper-response and five cycles (6%) were cancelled for insufficient follicular growth. The pregnancy rate per started treatment cycle and per cycle given HCG was 18 and 22.4% respectively. Pregnancy was achieved by 15 (39.5%) of the 38 patients. Mild to moderate ovarian hyperstimulation syndrome occurred in three patients. Local tolerance was good. CONCLUSIONS: This study confirms that combined rFSH and rLH treatment induces follicular growth, ovulation and pregnancy in a good proportion of hypogonadotrophic anovulatory patients and is well tolerated. The doses of 150 IU rFSH and 75 IU rLH daily seem the most appropriate but in a small minority of patients doses >75 IU rLH/day may be necessary.

Adult↗
PubMed2002

In-vivo ovarian androgen responses to recombinant FSH with and without recombinant LH in polycystic ovarian syndrome.

BACKGROUND: Effects of exogenous LH on ovarian androgen secretion during ovulation induction have not been clearly characterized in polycystic ovarian syndrome (PCOS). The purpose of this study was to compare androgen secretion in PCOS women during ovarian stimulation with either recombinant FSH (rFSH) alone or combined with recombinant LH (rLH). METHODS: Clomiphene-resistant women with PCOS were allocated, in a factorial study design, to receive either daily injections of rFSH (n = 24) or rFSH + rLH (n = 24) in a 1:1 ratio starting: (i) on day 2-3 of progestogen-induced menses (n = 8); (ii) after 6 weeks of GnRH agonist treatment (nafarelin, 400 micro g twice daily; n = 8); or (iii) after nafarelin treatment as in (ii) plus dexamethasone (n = 8). The effects of rFSH with rFSH + rLH under these three hormone conditions on serum LH, 17alpha-hydroxyprogesterone (17-OHP), androstenedione (DeltaDelta(4)) and testosterone were contrasted by analysis of variance with specific treatment days as a repeated measures factor. RESULTS: Pre-study hormone levels were similar for all groupings. Nafarelin significantly suppressed LH levels, which remained at the lower limit of assay sensitivity (0.5 IU/l) during stimulation with rFSH but increased significantly to >1 but <2 IU/l when rLH was added. As expected, 17-OHP, DeltaDelta(4) and testosterone levels fell following nafarelin treatment. Dexamethasone further suppressed 17-OHP, DeltaDelta(4) and testosterone levels and unmasked a small but significant rise in these ovarian steroids 24 h following the first dose of rFSH + rLH, a rise that was absent with rFSH alone. Secretion of these steroids then appeared to 'catch-up' after 5 days of rFSH stimulation. CONCLUSIONS: Despite profound LH, 17-OHP, DeltaDelta(4) and testosterone suppression, comparable E(2) response, follicle development and successful pregnancies in PCOS subjects receiving rFSH alone to those receiving rFSH + rLH would argue that circulating LH at levels as low as 0.5 IU/l are sufficient to sustain adequate follicle development and function when FSH is present in abundance. Whether the observed dichotomy between rFSH and rFSH + rLH treatment in temporal secretion patterns reflects a greater reliance on evolving paracrine mechanisms as the follicles mature under profound LH suppression remains to be explored but may influence the optimal LH threshold for ovulation induction in PCOS.

17-alpha-Hydroxyprogesterone↗
PubMed2005

Recombinant luteinizing hormone supplementation to recombinant follicle-stimulating hormone induced ovarian hyperstimulation in the GnRH-antagonist multiple-dose protocol.

BACKGROUND: Suppression of endogenous LH production by mid-follicular phase GnRH-antagonist administration in controlled ovarian hyperstimulation protocol using recombinant (rec) FSH preparations void of LH activity may potentially affect ovarian response and the outcome of IVF treatment. The present study prospectively assessed the effect of using a combination of recFSH and recLH on ovarian stimulation parameters and treatment outcome in a fixed GnRH-antagonist multiple dose protocol. METHODS: 127 infertile patients with an indication for IVF or ICSI were recruited and randomized (using sealed envelopes) to receive a starting dose of either 150 IU recFSH (follitropin alpha) or 150 IU recFSH plus 75 IU recLH (lutropin alpha) for ovarian hyperstimulation. GnRH-antagonist (Cetrorelix) 0.25 mg was administered daily from stimulation day 6 onwards up to and including the day of the administration of recombinant HCG (chorion gonadotropin alpha). Gonadotropin dose adjustments were allowed from stimulation day 6 onwards, HCG was administered as soon as three follicles > or =18 mm were present. The primary outcome parameter was treatment duration until administration of HCG. RESULTS: Exogenous LH did not shorten the time necessary to reach ovulation induction criteria. Serum estradiol (E(2)) and LH levels were significantly higher on the day of HCG administration in the recLH-supplemented group (1924.7 +/- 1256.4 vs 1488.3 +/- 824.0 pg/ml, P < 0.03), and 2.1 +/- 1.4 vs 1.4 +/- 1.5 IU/l, P < 0.01, respectively). CONCLUSIONS: Except for higher E(2) and LH levels on the day of HCG administration, no positive trend in favour of additional LH was found as defined by treatment outcome parameters.

Adult↗
PubMed1990

Three-drug synergistic inhibition of HIV-1 replication in vitro by zidovudine, recombinant soluble CD4, and recombinant interferon-alpha A.

Optimal management of human immunodeficiency virus type 1 (HIV-1) infections may require combinations of agents that attack different targets in the viral replicative cycle. Zidovudine (AZT), recombinant soluble CD4 (rsCD4), and recombinant interferon-alpha A (rIFN-alpha A) were evaluated in 2- and 3-drug regimens against HIV-1 replication in vitro. Peripheral blood mononuclear cells and a CD4+ T cell line (H9) were studied using multiple HIV-1 replicative end points. Drug interactions were evaluated by the median-effect principle and the isobologram technique. AZT, rsCD4, and rIFN-alpha A inhibited HIV-1 synergistically in 2- and 3-drug combinations. The 3-drug regimen provided more complete virus suppression than the 2-drug regimens. In H9 cells, single-drug regimens lost effectiveness at 10-14 days and 2-drug regimens lost effectiveness at 14-18 days. In contrast, the 3-drug regimen showed nearly complete suppression over 28 days in culture without toxicity. Clinical trials of these 3 drugs in combination should be considered.

CD4 Antigens↗
PubMed2001

Limited effect of chromatin remodeling on D(beta)-to-J(beta) recombination in CD4+CD8+ thymocyte: implications for a new aspect in the regulation of TCR beta gene recombination.

We have generated mutant mice in which TCR beta chain enhancer (E(beta)) was replaced with the TCR alpha chain enhancer (E(alpha)). Using this mouse model, we analyzed (i) recombination status of the TCR beta chain genes after functional V(D)J rearrangements occurred in the first allele during double-negative (DN)-to-double-positive (DP) transition and (ii) involvement of E(beta) for the expression of rearranged TCR beta chain genes. Our data show that E(alpha) substituted for E(beta) function to express a similar extent of TCR beta chains exactly at the same time as did E(beta) (CD25+CD44- DN stage), although the proportion of TCR beta+ cells at this stage was low in mutant mice. At the DP stage, germline transcription and histone acetylation of D(beta)-J(beta) loci were detectable at a high degree in both mutant and wild-type mice. However, DP cells in mutant mice retained the germline D(beta)-J(beta) configuration at a higher frequency than that of wild-type mice, whereas both DP cells expressed TCR beta chains to a similar extent. These data suggest that chromatin opening has a limited impact on D(beta)-to-J(beta) recombination at the DP stage and that E(alpha) is functionally equivalent to E(beta) in promoting expression of functionally rearranged TCR beta chain genes through DN-to-DP transition.

Animals↗
PubMed1998

Pilot study of the immunologic effects of recombinant human growth hormone and recombinant insulin-like growth factor in HIV-infected patients.

OBJECTIVE: To study the immunologic effects of recombinant human growth hormone (rhGH), recombinant human insulin-like growth factor type 1 (rhIGF-1), or the combination, in patients with moderately advanced HIV infection. DESIGN: Randomized but not blinded trial. SETTING: Government medical research center. PATIENTS: Twenty-four HIV-infected patients with CD4 cell counts of 100-400 x 10(6)/l who were receiving nucleoside antiretroviral therapy. INTERVENTIONS: Either rhGH, rhIGF-1, or the combination was administered subcutaneously for 12 weeks. MAIN OUTCOME MEASURES: Immunologic parameters, including T-cell subsets and assays of in vitro interleukin (IL)-2 production in response to antigens and mitogens, and safety profile. RESULTS: Plasma IGF-1 levels were low or low-normal prior to treatment and increased with all three therapies. There were no significant changes in CD4 cell counts, RA/RO CD4 cell subsets, natural killer cell function, immunoglobulin levels, or in vitro IL-2 production in response to mitogen or alloantigens. However, there was an upward trend (and for p18IIIB a statistically significant increase) in the in vitro IL-2 production in response to each of five HIV envelope peptides. Potential toxic effects included fatigue, arthralgia, edema, myalgia, and headache. Patients also were noted to have weight gain averaging 4 kg early in the course of treatment. CONCLUSIONS: These results suggest that treatment with rhGH/rhIGF-1 was reasonably well tolerated and that modest improvement in HIV-specific immune function was attained. Further studies will help clarify the therapeutic potential of rhGH/rhIGF-1 as an immunostimulator in the setting of HIV infection.

Adult↗
PubMed1992

Phase I trial of recombinant interleukin-2 followed by recombinant tumor necrosis factor in patients with metastatic cancer.

In this Phase I trial, the feasibility of sequential administration of continuous intravenous recombinant interleukin-2 (rIL-2) at 18 x 10(6) IU/m2/day for 6 days, followed by three daily bolus intravenous recombinant tumor necrosis factor (rTNF) infusions at doses escalating between 10 and 120 micrograms/m2/day, was investigated in 31 patients with metastatic malignancies. Prophylactic use of indomethacin prior to and during rTNF administration was found to significantly reduce toxicity. However, despite prophylactic indomethacin, a maximum tolerated dose of rTNF of 120 micrograms/m2 was reached. The limiting toxicity was hypotension. Predictable flu-like toxicities (i.e., fever/chills, hypotension, gastrointestinal toxicity, edema, malaise) were seen in most patients. These started during the rIL-2 infusion and continued during rTNF administration, particularly in the absence of indomethacin. Hematological, renal, and hepatic toxicities were not dose limiting. These toxicities were all reversible after treatment interruption. Pulmonary toxicity [i.e., anaphylactic-like reactions, bronchospasms, and adult respiratory distress syndrome (ARDS)] was seen in several patients immediately after rTNF infusions, irrespective of the rTNF dose or treatment cycle, and mainly in patients with extensive pulmonary metastases. The combined effect of treatment-related ARDS, lung metastases, and a Guillain-Barré syndrome led to the death of one patient. Two partial responses were seen in this study (i.e., breast and renal cancer). Based on these results, a Phase II trial of rIL-2 followed by rTNF has been initiated in metastatic breast cancer patients.

Adolescent↗
PubMed1992

A Southwest Oncology Group Phase I study of the sequential combination of recombinant interferon-gamma and recombinant interleukin-2 in patients with cancer.

Thirty-seven patients with advanced malignancies were treated sequentially with recombinant interferon-gamma (rIFN-gamma) and recombinant interleukin-2 (rIL-2) in an outpatient dose escalation clinical trial. rIFN-gamma (0.1 or 0.25 mg/m2/day) was administered by intramuscular injection, days 1-7 and rIL-2 (12, 18, or 24 x 10(6) IU/m2/day) was administered by a 15-min intravenous bolus, days 8-12. Common toxicities encountered included fever, chills, fatigue, neutropenia, and elevations of SGOT, bilirubin, or creatinine. Hypotension and cardiac and pulmonary toxicities were rare. With repeated cycles of therapy, nausea/vomiting and diarrhea associated with the administration of rIL-2 were seen in greater frequency. There were no treatment-related deaths, and no patient required intensive care unit admission for toxicity management. A complete response was observed in one of 11 patients with renal cancer and a partial response was observed in one of seven patients with malignant melanoma. Due to problems with drug supply, further dose escalation could not be continued, and maximum tolerated doses (MTD) were not determined by strict criteria. However, the combination of rIFN-gamma, 0.25 mg/m2/day, and rIL-2, 24 x 10(6) IU/m2/day, appeared to be beyond the MTD, as three of six patients at this dose level could not complete one cycle of therapy due to toxicity. It is unlikely that higher doses of either agent would be tolerated, and for further study using this schedule, we recommend the doses: rIFN-gamma, 0.1 mg/m2/day, and rIL-2, 24 x 10(6) IU/m2/day.

Adult↗
PubMed1997

Recombinant interleukin-2 in combination with recombinant interferon-gamma in patients with advanced malignancy: a phase 1 study.

Because interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) act synergistically in vitro in the generation of lymphokine-activated killer (LAK) cells. we initiated a clinical trial of these lymphokines in combination. Twenty patients with advanced malignancy were treated at fixed dose levels of recombinant IFN-gamma given by intramuscular (i.m.) injections once a day and recombinant IL-2 given by an intravenous (i.v.) bolus injection 3 times a day for 7 days after a 3-day treatment with fixed doses (250 micrograms/m2/day) of IFN-gamma alone. A minimum of four patients were treated at each of the four dose levels studied. The side effects of the combination therapy were similar to those seen with individual lymphokines and included fever and chills, myalgia, headache, fatigue, nausea. vomiting, peripheral edema, skin rash, and hypotension. The maximum tolerated dose for the combination after a fixed dose of IFN-gamma was 2 x 10(5) U/M2/day (10 micrograms/m2/day) of IFN-gamma and 3 x 10(6) U/M2/day of IL-2, with fluid retention as the dose-limiting toxicity. Whereas natural killer (NK) or LAK activity or both were significantly increased in four of eight patients studied, only one patient with renal cell cancer had a minor response for four treatment cycles. We conclude that combination therapy with cytokines IL-2 and IFN-gamma given in this schedule had manageable toxicity and exhibited immunomodulatory effects in some patients but had no significant antitumor activity in this patient population.

Adult↗
PubMed2002

Comparison of recombinant granulocyte colony-stimulating factor, recombinant human granulocyte-macrophage colony-stimulating factor and placebo for treatment of septic preterm infants.

BACKGROUND: To reduce morbidity and mortality adjuvant cytokine therapy was administered to septic neonates with variable results. The objective of this case series was to compare the effectiveness of recombinant human granulocyte-macrophage colony-stimulating factor (rhuGM-CSF) and recombinant granulocyte colony-stimulating factor (rG-CSF) with that of placebo in correcting neutropenia induced by sepsis. METHODS: Symptomatic, septic premature neonates with or without a positive blood culture were eligible. Twenty-eight patients were randomized: 10 received rG-CSF (5 microg/kg/dose i.v. twice a day); 10 received rhuGM-CSF (4 microg/kg/dose i.v. twice a day) and 8 received placebo for a maximum of 7 days, or until an absolute neutrophil count (ANC) of 10,000 cells/mm was reached. RESULTS: A significant increase in the ANC above the baseline was present on Day 2 in the rG-CSF group (P = 0.015) and on Day 5 in the rhuGM-CSF (P = 0.002) and placebo (P = 0.027) groups. The ANC of the rG-CSF group was significantly above that in the rhuGM-CSF and placebo groups on Day 7 (P = 0.03). Mortality and neonatal intensive care unit morbidity was not significantly different between the groups. CONCLUSION: The neutrophil count in the rG-CSF-treated group increased significantly faster than that in the placebo or rhuGM-CSF group.

Anti-Infective Agents↗
PubMed1997

An increase in peripheral blood progenitor cells in primates by coadministration of recombinant human interleukin 6 and recombinant human granulocyte colony-stimulating factor.

BACKGROUND: We recently demonstrated that coadministration of recombinant human interleukin 6 (rhIL-6) and recombinant human granulocyte colony-stimulating factor (rhG-CSF) in mice synergistically increases peripheral blood stem cells (PBSC), which can rescue lethally irradiated recipient mice. However, there is little information about the effect of coadministration of rhIL-6 and rhG-CSF on PBSC in a primate system. METHODS: In cynomolgus monkeys, rhG-CSF (5 microg/kg day) alone was administered for 5 days (first cycle). After the wash-out period, rhIL-6 (0, 10, or 20 microg/kg/day) and rhG-CSF were coadministered for 5 days (second cycle). RESULTS: Total peripheral colony-forming cells levels were increased earlier by coadministration of rhIL-6 and rhG-CSF than by the administration of rhG-CSF alone. The maximum level in the coadministration cycle was obtained on day 5, and a high level was obtained for a further 3 days after cessation. The maximum number of peripheral total colony-forming cells in the coadministration cycle was a mean of 2.12-fold (range 1.38 to 3.35) higher than that in the rhG-CSF alone cycle. Coadministration also increased the peripheral mixed colony-forming units by a mean of 3.62-fold (range 1.02 to 5.52). Interestingly, monkeys that showed a low response to the administration of rhG-CSF alone also had a higher response to the coadministration. No significant difference was observed between the two cycles of administration of rhG-CSF alone. CONCLUSIONS: These findings suggest that coadministration of rhIL-6 and rhG-CSF may be useful for clinical PBSC collection.

Alkaline Phosphatase↗
PubMed1989

Changes in lymphocyte subsets following multiple administration of recombinant interleukin-2 plus recombinant interferon-beta or -gamma in tumor-bearing mice.

Treatment with a combination of recombinant human interleukin-2 (rHIL-2) and recombinant mouse interferon-beta (rIFN-beta) or -gamma (rIFN-gamma) showed a significant antitumor effect against sc adenocarcinoma 755 in mice, although treatment with either one alone had almost no effect. The combination of rHIL-2 and rIFN-beta caused regression of the tumor but the combination of rHIL-2 and rIFN-gamma did not. Injection of tumor-bearing mice with the combinations of rHIL-2 and rIFN resulted in marked increases in the total number of peritoneal lymphocytes, and the frequency of Lyt-2+ cells was more markedly increased by the combination of rHIL-2 and rIFN-beta than by the combination of rHIL-2 and rIFN-gamma. In Winn assay, elimination of the Lyt-2+ population abolished the protective capacity of the peritoneal cells. The subsets of thymocytes were drastically changed when mice were bearing a tumor or were treated with cytokines. In particular, Lyt-2+/L3T4+ cells were decreased in tumor-bearing mice, but many Lyt-2+/L3T4+ cells were maintained in the thymus by treatment with a cytokine alone. When treated with rHIL-2 and rIFN-beta, the Lyt-2+/L3T4+ cells were markedly decreased, while Lyt-2+/L3T4- T-cells were increased, but these subsets were little changed by treatment with rHIL-2 plus rIFN-gamma. Thus, injections of rHIL-2 and rIFN-beta into tumor-bearing mice resulted in a high frequency of Lyt-2+/L3T4- cells in the peritoneal cavity, together with changes in the T-cell subsets in the thymus. These results suggest that maturation of T-cells in the thymus may be an important step in the pathway by which cytokine treatment brings about regression of tumors.

Adenocarcinoma↗
PubMed1989

Enhancement of cytotoxicity of cisplatin in vitro by recombinant human tumor necrosis factor and/or recombinant human interferon-alpha, -beta and -gamma.

This study was conducted to investigate the modulatory effects of recombinant human tumor necrosis factor (rH-TNF) and recombinant human interferon (rH-IFN)-alpha, -beta and -gamma, either alone or in combination, on the cytotoxicity of cisplatin, using MTT assay, against MKN-45 (human stomach adenocarcinoma). MKN-45 was resistant to rH-TNF even at doses up to 10(3) U/ml. rH-IFN-gamma inhibited the survival of MKN-45 dose-dependently, while rH-IFN-alpha and -beta did not inhibit the survival of MKN-45 even at the highest concentrations tested (10(4) U/ml). Combination of rH-TNF with rH-IFN-alpha, -beta or -gamma did not significantly inhibit the survival of MKN-45, except for a combination of 10 U/ml of rH-TNF and 10(3) U/ml of rH-IFN-gamma (P less than 0.05). Cisplatin inhibited the survival of MKN-45 dose-dependently. By the simultaneous combination of cisplatin with rH-TNF and/or rH-IFN-alpha, -beta or -gamma, cytotoxicity of cisplatin was enhanced and the combination effects were additive. The effects of rH-TNF and rH-IFN-alpha, -beta and -gamma on the modification of cytotoxicity of cisplatin were evaluated in terms of modification index (MI), demonstrating that rH-TNF, rH-IFN-alpha, -beta and -gamma all augmented the cytotoxicity of cisplatin: MI values at 10(3) U/ml of rH-IFN-alpha, -beta and -gamma were 1.4, 1.4 and 2.3, respectively; those at the same concentrations of rH-IFN-alpha, -beta and -gamma in the presence of 10 U/ml of rH-TNF were 3.6, 2.5 and 5.1, respectively. These results demonstrating that the cytotoxicity of cisplatin was enhanced by rH-TNF and/or rH-IFN-alpha, -beta or -gamma suggest that cancer may be more effectively treated with the combination of cisplatin with these biological response modifiers than with cisplatin alone.

Adenocarcinoma↗