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At least 595 records · Page 33Linked to original sources
PubMed2001

Cytokine responses to human immunodeficiency virus type 1 (HIV-1) induced by immunization with live recombinant canarypox virus vaccine expressing HIV-1 genes boosted by HIV-1(SF-2) recombinant GP120.

Vaccine-induced T-cell memory for human immunodeficiency virus type 1 (HIV-1) was assessed by measuring HIV-1 antigen-stimulated cytokine secretion in 72 HIV-1-uninfected subjects, of whom 52 received live recombinant canarypox virus vaccine expressing HIV-1 env, gag, and protease gene products (vCP205) with or without HIV-1(SF-2) recombinant gp120 (SF-2 rgp120) subunit vaccine, and 20 the control. The vCP205 vaccine induced secretion of the Th1 cytokine, interferon-gamma, by peripheral blood mononuclear cells (PBMC) after in vitro stimulation with HIV-1 p24 and envelope glycoprotein. Immunization schedules with both vCP205 and SF-2 rgp120 subunit vaccines induced secretion of Th1 and Th2 cytokines by PBMC to HIV-1 envelope glycoprotein. Hence, vCP205 and SF-2 rgp120 subunit vaccines given together and in a prime-boost sequence appeared to induce a broader cytokine response pattern than vCP205 vaccine given alone.

AIDS Vaccines↗
PubMed2004

Randomized trial to compare the effect of recombinant human FSH (follitropin alfa) with or without recombinant human LH in women undergoing assisted reproduction treatment.

Women undergoing intracytoplasmic sperm injection (ICSI) for male factor infertility were randomly assigned to receive ovarian stimulation in a long agonist protocol with a combination of recombinant human FSH (r-hFSH; Gonal-F) and recombinant human LH (r-hLH; Luveris) (n = 212) starting on day 6 of FSH stimulation until human chorionic gonadotrophin (HCG) at a daily fixed dose of 150 IU r-hLH, or with r-hFSH alone (n = 219). There was no significant difference in the number of metaphase II oocytes retrieved (10.3 versus 10.4) in patients treated with r-hFSH and r-hLH versus r-hFSH alone; however, more embryos were transferred in the LH-supplemented group (2.9 versus 2.8, P = 0.037). Overall, the implantation rates were 22.9 versus 27.0% in patients treated with r-hFSH and r-hLH versus with r-hFSH alone respectively (NS). The respective numbers of MII oocytes retrieved in patients <35 or >or=35 years were 11 versus 8.3 (P = 0.010) for patients treated with r-hFSH alone, and 10.7 versus 9.3 (NS) for those given supplemental r-hLH (150 IU) from day 6. Implantation rates in patients <35 years treated with r-hFSH were higher (30.7%) than those receiving r-hFSH and r-hLH, (23.5%) (P = 0.068). In patients >or=35 years, the implantation rates were 21.7% for those patients supplemented with 150 IU r-hLH from day 6 of stimulation versus 15.7% when treated with FSH alone (NS). Younger patients therefore do not seem to benefit from an LH-supplemented ovarian stimulation protocol, but women >or=35 years undergoing assisted reproduction may benefit from using r-hLH in addition to r-hFSH.

Adolescent↗
PubMed1995

Charge recombination reactions in photosystem II. I. Yields, recombination pathways, and kinetics of the primary pair.

Recombination reactions of the primary radical pair in photosystem II (PS II) have been studied in the nanosecond to millisecond time scales by flash absorption spectroscopy. Samples in which the first quinone acceptor (QA) was in the semiquinone form (QA-) or in the doubly reduced state (presumably QAH2) were used. The redox state of QA and the long-lived triplet state of the primary electron donor chlorophyll (3P680) were monitored by EPR. The following results were obtained at cryogenic temperatures (around 20 K). (1) the primary radical pair, P680+Pheo-, is formed with a high yield irrespective of the redox state of QA. (2) The decay of the primary pair is faster with QA- than with QAH2 and could be described biexponentially with t1/2 approximately 20 ns (approximately 65%)/150 ns (approximately 35%) and t1/2 approximately 60 ns (approximately 35%)/250 ns (approximately 65%), respectively. The different kinetics may be due to electrostatic and/or magnetic effects of QA- on charge recombination or due to conformational changes caused by the double reduction treatment. (3) The yield of the triplet state 3P680 was high both with QA- and QAH2. (4) The triplet decay was much faster with QA- [t1/2 approximately 2 microseconds (approximately 50%)/20 microseconds (approximately 50%)] than with QAH2 [t1/2 approximately 1 ms (approximately 65%)/3 ms (approximately 35%)]. The short lifetime of the triplet with QA- explains why it was not detected earlier. The mechanism of triplet quenching in the presence of QA- is not understood; however it may represent a protective process in PS II. (5) Almost identical data were obtained for PS II-enriched membranes from spinach and PS II core preparations from Synechococcus. Room temperature optical studies were performed on the Synechococcus preparation. In samples containing sodium dithionite to form QA- in the dark, EPR controls showed that multiple excitation flashes given at room temperature led to a decrease of the QA-Fe2+ signal, indicating double reduction of QA. During the first few flashes, QA- was still present in the large majority of the centers. In this case, the yield of the primary pair at room temperature was around 50%, and its decay could be described monoexponentially with t1/2 approximately 8 ns (a slightly better fit was obtained with two exponentials: t1/2 approximately 4 ns (approximately 80%)/25 ns (approximately 20%).(ABSTRACT TRUNCATED AT 400 WORDS)

Cyanobacteria↗
PubMed1999

High-titer recombinant adeno-associated virus production utilizing a recombinant herpes simplex virus type I vector expressing AAV-2 Rep and Cap.

Recombinant adeno-associated virus type 2 (rAAV) vectors have recently been used to achieve long-term, high level transduction in vivo. Further development of rAAV vectors for clinical use requires significant technological improvements in large-scale vector production. In order to facilitate the production of rAAV vectors, a recombinant herpes simplex virus type I vector (rHSV-1) which does not produce ICP27, has been engineered to express the AAV-2 rep and cap genes. The optimal dose of this vector, d27.1-rc, for AAV production has been determined and results in a yield of 380 expression units (EU) of AAV-GFP produced from 293 cells following transfection with AAV-GFP plasmid DNA. In addition, d27.1-rc was also efficient at producing rAAV from cell lines that have an integrated AAV-GFP provirus. Up to 480 EU/cell of AAV-GFP could be produced from the cell line GFP-92, a proviral, 293 derived cell line. Effective amplification of rAAV vectors introduced into 293 cells by infection was also demonstrated. Passage of rAAV with d27. 1-rc results in up to 200-fold amplification of AAV-GFP with each passage after coinfection of the vectors. Efficient, large-scale production (>109 cells) of AAV-GFP from a proviral cell line was also achieved and these stocks were free of replication-competent AAV. The described rHSV-1 vector provides a novel, simple and flexible way to introduce the AAV-2 rep and cap genes and helper virus functions required to produce high-titer rAAV preparations from any rAAV proviral construct. The efficiency and potential for scalable delivery of d27.1-rc to producer cell cultures should facilitate the production of sufficient quantities of rAAV vectors for clinical application.

Blotting, Western↗
PubMed2001

Recombinant DNA vaccines protect against tumors that are resistant to recombinant vaccinia vaccines containing the same gene.

Antigen-specific cancer immunotherapy involves the delivery of tumor-associated antigen to the host for the generation of tumor-specific immune responses and antitumor effects. We hypothesized that different delivery systems may influence the pattern of antigen-specific immune response and the outcome of antitumor effect. We therefore evaluated recombinant vaccinia virus and naked DNA for the generation of antigen-specific immune responses and antitumor effects. We previously found that recombinant vaccinia and naked DNA vaccines containing the chimeric Sig/E7/LAMP-1 gene were capable of controlling the growth of HPV-16 E7-expressing tumor cells (TC-1). In this study, we performed a head-to-head comparison of optimized delivery of Sig/E7/LAMP-1 vaccinia and DNA vaccines using dose-escalating tumor challenge. At a dose of 1 x 10(6) TC-1 cells per mouse, Sig/E7/LAMP-1 DNA provided 100% protection against subcutaneous growth of tumors, while Vac-Sig/E7/LAMP-1 protected only 40% of the mice. Furthermore, Sig/E7/LAMP-1 DNA vaccines are capable of protecting against challenge with a more stringent subclone of TC-1 (TC-1 P2) established from TC-1 tumors that survived initial Sig/E7/LAMP-1 vaccinia vaccination. Immunological assays revealed that both vaccines induced comparable levels of CD8(+) T cell precursors and anti-E7 antibody titers. Interestingly, Sig/E7/LAMP-1 vaccinia induced both E7-specific IFN-gamma- and IL4-secreting CD4(+) T cell precursors while Sig/E7/LAMP-1 DNA induced only E7-specific IFN-gamma-secreting CD4(+) T cell precursors. We also found that IL-4 knockout C57BL/6 mice vaccinated with Sig/E7/LAMP-1 vaccinia exhibited a more potent antitumor effect than vaccinated wild-type C57BL/6 mice in our tumor protection experiments. These results suggest that IL-4 may play a detrimental role in the antitumor effect mediated by vaccinia vaccines. Our findings suggested that DNA vaccines may provide better tumor protection than vaccinia vaccines employing the same gene, which may have implications in the future design of antigen-specific cancer immunotherapy.

Animals↗
PubMed2000

Recombination of simple molecular ions studied in storage ring: dissociative recombination of H2O+

Dissociative recombination of vibrationally relaxed H2O+ ions with electrons has been studied in the heavy-ion storage ring CRYRING. Absolute cross-sections have been measured for collision energies between 0 eV and 30 eV. The energy dependence of the cross-section below 0.1 eV is found to be much steeper than the E-1 behaviour associated with the dominance of the direct recombination mechanism. Resonant structures found at 4 eV and 11 eV have been attributed to the electron capture to Rydberg states converging to electronically excited ionic states. Complete branching fractions for all dissociation channels have been measured at a collision energy of 0 eV. The dissociation process is dominated by three-body H + H + O breakup that occurs with a branching ratio of 0.71.

Journal Article↗
PubMed1995

A prime-boost approach to HIV preventive vaccine using a recombinant canarypox virus expressing glycoprotein 160 (MN) followed by a recombinant glycoprotein 160 (MN/LAI). The AGIS Group, and l'Agence Nationale de Recherche sur le SIDA.

The safety and the immunogenicity of a recombinant canarypox live vector expressing the human immunodeficiency virus type 1 (HIV-1) gp160 gene from the MN isolate, ALVAC-HIV (vCP125), followed by booster injections of a soluble recombinant hybrid envelope glycoprotein MN/LAI (rgp160), were evaluated in vaccinia-immune, healthy adults at low risk for acquiring HIV-1 infection. Volunteers (n = 20) received vCP125 (10(6) TCID50) at 0 and 1 month, followed randomly by rgp160 formulated in alum or in Freund's incomplete adjuvant (FIA) at 3 and 6 months. Local and systemic reactions were mild or moderate and resolved within the first 72 hr after immunization. No significant biological changes in routine tests were observed in any volunteer. Two injections of vCP125 did not elicit antibodies. Neutralizing antibodies (NA) against the HIV-1 MN isolate were detected in 65 and 90% of the subjects after the first and the second rgp 160 booster injections, respectively. Six months after the last boost, only 55% were still positive. Seven of 14 sera with the highest NA titers against MN weakly cross-neutralized the HIV-1 SF2 isolate; none had NA against the HIV-1 LAI or against a North American primary isolate. Specific lymphocyte T cell proliferation to rgp 160 was detected in 25% of the subjects after vCP125 and in all subjects after the first booster injection and 12 months after the first injection. An envelope-specific cytotoxic lymphocyte activity was found in 39% of the volunteers and characterized for some of them as CD3+, CD8+, MHC class I restricted. The adjuvant formulation did not influence significantly the immune responses.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS Vaccines↗
PubMed2000

The DNA-bending protein, HMG1, is required for correct cleavage of 23 bp recombination signal sequences by recombination activating gene proteins in vitro.

DNA-bending proteins are known to facilitate the in vitro V(D)J joining of antigen receptor genes. Here we report that the high-mobility group protein, HMG1, is necessary for the correct nicking of the 23 bp recombination signal sequence (23-RSS) by the recombination [corrected] activating gene (RAG) proteins, RAG1 and RAG2. Without HMG1, the mouse Jkappa1 23-RSS was recognized as if it were the 12-RSS and nicked at a site 12 + 7 nucleotides away from the 9mer signal, even though no 7mer-like sequence was evident at the cryptic nicking site. When increased amounts of HMG1 were added, the 23-RSS substrate was nicked correctly at a site 23 + 7 nucleotides from the 9mer, and nicking at the cryptic site disappeared. Unlike the 23-RSS, the 12-RSS did not require HMG1 for correct nicking, although HMG1 was found to increase the interaction between RSS and RAG proteins. Modification-interference assays demonstrated that HMG1 caused changes in the interaction between the 23-RSS and RAG proteins specifically at the 7mer and the cryptic nicking site.

Animals↗
PubMed1992

Effects of recombinant human interleukin-6 alone and in combination with recombinant interleukin-1 alpha and tumor necrosis factor alpha on antibacterial resistance in mice.

In this study, recombinant human interleukin-6 (rIL-6) was tested for its ability to alter the resistance of mice to experimental Listeria monocytogenes infection. Single bolus or repeated injections of rIL-6 by itself did not increase antilisteria resistance. When rIL-6 was injected in combination with suboptimal concentrations of rIL-1 alpha and tumor necrosis factor alpha (rTNF-alpha), it did not augment their abilities to mediate protection in the spleen and had a marginal effect on the level of protection in the liver. Injection of rIL-6 together with protective doses of rIL-1 alpha did not diminish the protection stimulated by the latter. Unlike rIL-1 alpha and recombinant tumor necrosis factor alpha, rIL-6 appears to have little ability to elevate antibacterial resistance.

Animals↗
PubMed2002

Mucosal immunization with live recombinant bovine respiratory syncytial virus (BRSV) and recombinant BRSV lacking the envelope glycoprotein G protects against challenge with wild-type BRSV.

Recombinant bovine respiratory syncytial virus (rBRSV) and an rBRSV deletion mutant lacking the G gene (rBRSVDeltaG) were characterized in calves with respect to replication competence, attenuation, and protective efficacy as live-attenuated BRSV vaccines. Both recombinant viruses were safe and induced protection against a BRSV challenge infection. rBRSV replicated efficiently in the upper respiratory tract. Intranasal immunization with rBRSVDeltaG led to infection but not to mucosal virus replication. Neutralizing antibodies were induced by rBRSV and rBRSVDeltaG. Thus, the BRSV attachment glycoprotein G seems to be dispensable in vaccinating calves against BRSV.

Administration, Intranasal↗
PubMed1992

Acceleration of recombinant tissue-type plasminogen activator-induced reperfusion and prevention of reocclusion by recombinant antistasin, a selective factor Xa inhibitor, in a canine model of femoral arterial thrombosis.

Antistasin is a 119-amino acid protein initially isolated from salivary glands of the Mexican leech, Haementeria officinalis, that exhibits potent anticoagulant properties resulting from selective inhibition of blood coagulation factor Xa. The comparative antithrombotic efficacies of recombinant antistasin (rATS), standard heparin (Hep), and aspirin (ASA) administered adjunctly with recombinant tissue-type plasminogen activator (tPA) on thrombolytic reperfusion and reocclusion were determined in a canine model of femoral arterial thrombosis. An occlusive thrombus was formed by insertion of a thrombogenic copper coil into the femoral artery, and blood flow velocity was monitored directly and continuously by Doppler flowmetry. Sixty minutes after occlusion, dogs received an intravenous infusion of either saline (vehicle) or rATS (0.31, 1.25, or 2.5 micrograms/kg/min), intravenous boluses of Hep (100 units/kg + 50 units/kg/hr or 200 units/kg + 150 units/kg/hr), or a single intravenous bolus of ASA (2.0 mg/kg), followed 45 minutes later by tPA (0.8 mg/kg i.v. over 90 minutes). The saline and rATS infusions were discontinued 60 minutes after termination of tPA, and the last Hep boluses were given 105 minutes after termination of tPA. All dogs achieved reperfusion. The time to reperfusion in the ASA group was similar to that in the vehicle group (50 +/- 9 versus 50 +/- 6 minutes, respectively). Reperfusion times were slightly decreased by the low and high doses of Hep (34 +/- 6 and 31 +/- 4 minutes, respectively) and the rATS doses of 0.31 and 1.25 micrograms/kg/min (37 +/- 4 and 36 +/- 5 minutes, respectively). However, the time to reperfusion was dramatically reduced with the 2.5 micrograms/kg/min rATS dose (15 +/- 3 minutes, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2000

Phase I study in advanced cancer patients of a diversified prime-and-boost vaccination protocol using recombinant vaccinia virus and recombinant nonreplicating avipox virus to elicit anti-carcinoembryonic antigen immune responses.

PURPOSE: This trial sought to determine, for the first time, the validity in human vaccinations of using two different recombinant vaccines in diversified prime-and-boost regimens to enhance T-cell responses to a tumor antigen. PATIENTS AND METHODS: Eighteen patients with advanced tumors expressing carcinoembryonic antigen (CEA) were randomized to receive either recombinant vaccinia (rV)-CEA followed by three avipox-CEA vaccinations, or avipox-CEA (three times) followed by one rV-CEA vaccination. Subsequent vaccinations in both cohorts were with avipox-CEA. Immunologic monitoring was performed using a CEA peptide and the enzyme-linked immunospot assay for interferon gamma production. RESULTS: rV-CEA followed by avipox-CEA was superior to the reverse order in the generation of CEA-specific T-cell responses. Further increases in CEA-specific T-cell precursors were seen when local granulocyte-macrophage colony-stimulating factor (GM-CSF) and low-dose interleukin (IL)-2 were given with subsequent vaccinations. The treatment was extremely well tolerated. Limited clinical activity was seen using vaccines alone in this patient population. Antibody production against CEA was also observed in some of the treated patients. CONCLUSION: rV-CEA was more effective in its role as a primer of the immune system; avipox-CEA could be given up to eight times with continued increases in CEA T-cell precursors. Future trials should use rV-CEA first followed by avipox-CEA. Vaccines specific to CEA are able to generate CEA-specific T-cell responses in patients without significant toxicity. T-cell responses using vaccines alone may be inadequate to generate significant anticancer objective responses in patients with advanced disease. Cytokines such as GM-CSF and IL-2 may play a key role in generating such responses.

Adult↗
PubMed2003

Modified vaccinia virus ankara recombinants are as potent as vaccinia recombinants in diversified prime and boost vaccine regimens to elicit therapeutic antitumor responses.

Cancer vaccine regimens use various strategies to enhance immune responses to specific tumor-associated antigens (TAAs), including the increasing use of recombinant poxviruses [vaccinia (rV) and fowlpox (rF)] for delivery of the TAA to the immune system. However, the use of replication competent vectors with the potential of adverse reactions have made attenuation a priority for next-generation vaccine strategies. Modified vaccinia Ankara (MVA) is a replication defective form of vaccinia virus. Here, we investigated the use of MVA encoding a tumor antigen gene, carcinoembryonic antigen (CEA), in addition to multiple costimulatory molecules (B7-1, intercellular adhesion molecule-1, and lymphocyte function-associated antigen-3 designated TRICOM). Vaccination of mice with MVA-CEA/TRICOM induced potent CD4+ and CD8+ T-cell responses specific for CEA. MVA-CEA/TRICOM could be administered twice in vaccinia naïve mice and only a single time in vaccinia-immune mice before being inhibited by antivector-immune responses. The use of MVA-CEA/TRICOM in a diversified prime and boost vaccine regimen with rF-CEA/TRICOM, however, induced significantly greater levels of both CD4+ and CD8+ T-cell responses specific for CEA than that seen with rV-CEA/TRICOM prime and rF-CEA/TRICOM boost. In a self-antigen tumor model, the diversified MVA-CEA/TRICOM/rF-CEA/ TRICOM vaccination regimen resulted in a significant therapeutic antitumor response as measured by increased survival, when compared with the diversified prime and boost regimen, rV-CEA/TRICOM/rF-CEA/TRICOM. The studies reported here demonstrate that MVA, when used as a prime in a diversified vaccination, is clearly comparable with the regimen using the recombinant vaccinia in both the induction of cellular immune responses specific for the "self"-TAA transgene and in antitumor activity.

Animals↗
PubMed1987

[Anti-neoplastic activity of a human recombinant tumor necrosis factor (Hu-rec-TNF) alone or in combination with human recombinant gamma-interferon, doxorubicin or cis-platinum on a human renal cell carcinoma line].

The inhibitory effect of human-recombinant tumor necrosis factor (Hu-rec-TNF) alone or in combination with human recombinant gamma-interferon (rec gamma-IFN), doxorubicin (ADM) or cis-platinum (CDDP) was studied for two human renal cell carcinoma lines (KO-RCC-1 and RCC-nu-1 cells). Hu-rec-TNF inhibited the cell growth of KO-RCC-1 cells in a dose- and time-dependent manner. The inhibitory effect was seen 48 hours after the treatment with Hu-rec-TNF alone. The effect of Hu-rec-TNF was cytotoxic in our experiment. On the other hand, Hu-rec-TNF did not inhibit the cell growth of RCC-nu-1 cells. There were sensitive and resistant cells in renal cell carcinoma. In KO-RCC-1 cells, Hu-rec-TNF enhanced the inhibitory effect of rec gamma-IFN, ADM or CDDP. On the other hand, Hu-rec-TNF did not enhance the inhibitory effect of rec gamma-IFN, ADM or CDDP in RCC-nu-1 cells. In our experiment, the combined treatment with Hu-rec-TNF and rec gamma-IFN, ADM or CDDP was useful in human renal cell carcinoma which was sensitive for Hu-rec-TNF.

Carcinoma, Renal Cell↗
PubMed1988

Differential in vitro effects of recombinant alpha-interferon and recombinant gamma-interferon alone or in combination on the expression of melanoma-associated surface antigens.

The effect of individual in vitro concentrations of recombinant alpha-interferon species A (rIFN-alpha-A), recombinant gamma-interferon (rIFN gamma), and combinations of both interferons on the expression of melanoma-associated surface antigens p97 and the high molecular weight proteoglycan (HWM-MAA-240K) as detected by monoclonal antibodies (MoAb) 96.5 and ZME 018 respectively, was examined. rIFN-alpha-A at optimal concentrations of 50 and 500 U/ml caused significant (p less than 0.05 and p less than 0.01, respectively) increases in expression of p97 on the melanoma cell line Hs 294t following a 48-h incubation. No change in 96.5 binding was noted with rIFN-alpha-A concentrations up to 1000 U/ml after a 24-h incubation. Likewise, rIFN gamma at an optimal concentration of 500 U/ml enhanced p97 expression slightly at 24 h (p = 0.053) and more significantly by 48 h at concentrations of 50, 500, and 1,000 U/ml (p less than 0.01, p less than 0.05, and p less than 0.025, respectively). In contrast, neither rIFN gamma nor rIFN-alpha-A had an effect on modulation of the HMW-MAA as detected by ZME 018, irrespective of dose or incubation time. Optimal and suboptimal concentrations of rIFN-alpha-A plus rIFN gamma in combination did not significantly enhance expression of either antigen to a greater extent than that observed with optimal concentrations of each IFN alone, despite the fact that the combination had a synergistic anti-proliferative effect. These data demonstrate that the effects of each interferon (IFN) on the expression of melanoma-associated antigens (MAA) are heterogeneous and depend on IFN type and concentration, exposure time, and characteristics of the antigen studied. Moreover, the data regarding combinations of rIFN-alpha-A and rIFN gamma suggest that mechanisms responsible for IFN effects on MAA modulation are independent from its effects on proliferation. These findings may have clinical relevance with respect to trials using combinations of alpha- and/or gamma-IFN plus MoAb in vivo.

Antigens, Neoplasm↗
PubMed1987

Augmentation of cytotoxic activity of recombinant human tumor necrosis factor (rHu-TNF) by recombinant human interferon-gamma (rHu-IFN-gamma).

The present study was undertaken to examine the effect of recombinant human interferon-gamma (rHu-IFN-gamma) on the in vitro antitumor activity of recombinant human tumor necrosis factor (rHu-TNF) against rHu-TNF-sensitive and resistant tumor cells. rHu-IFN-gamma augmented both cytostatic and cytocidal activity of rHu-TNF. When 14 tumor cells were tested, augmentation by rHu-IFN-gamma was observed in most of rHu-TNF-sensitive tumor cells and in few cases in rHu-TNF-resistant tumor cells. Among rHu-TNF-sensitive tumor cells, there was no relationship between the degree of augmentation and the susceptibility to rHu-TNF. Augmentation was marked when tumor cells were treated with rHu-IFN-gamma either before the exposure to rHu-TNF or during the early period of the exposure to rHu-TNF. On the other hand, augmentation was not observed when tumor cells were treated with rHu-IFN-gamma during a late period of the exposure to rHu-TNF. From these results, a combined treatment with both agents can be expected to provide an approach to get better results in clinical trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Role of recombinant interleukin-1 compared to recombinant T-cell replacing factor/interleukin-5 in B-cell differentiation.

The B-cell differentiation-inducing activity of interleukin-1 (IL-1) was compared with that of T-cell replacing factor (TRF)/interleukin-5 (IL-5), which was originally described as a late-acting B-cell differentiation-inducing factor. Human recombinant IL-1 and murine recombinant TRF/IL-5 were used in this study. Purified B cells from non-primed or antigen-primed mice, LPS-stimulated B-cell blasts, and chronic B-cell leukaemia (BCL1) cells were used as the responding B-cell population. Addition of IL-1 to the culture of normal B-cells and sheep red blood cells (SRBC) induced a dose-dependent anti-SRBC IgM response, with maximal response at 100 U/ml, whereas the response induced by TRF/IL-5 was less than that induced by IL-1 and did not reach the maximum even at 100 U/ml. Addition of anti-IL-1 antibody, but not anti-TRF/IL-5 antibody or anti-IL-2 receptor antibody, inhibited IL-1-induced anti-SRBC responses. Depletion of cells adherent to Sephadex beads from splenic B cells showed no significant effect on the magnitude of the total responses. IL-1 could induce little, if any, differentiation in antigen-primed B cells, LPS-stimulated B-cell blasts, or BCL1 cells into antibody-secreting cells, whereas differentiation could be induced by low doses of TRF/IL-5 (1-2 U/ml). Of great interest is that suboptimal doses of IL-1 (10 U/ml) could synergize with TRF in the primary anti-SRBC PFC responses. Kinetic studies revealed that IL-1 acts on B cells for the first 2 days and TRF/IL-5 for the last 3 days in 5-day cultures of B cells. These results suggest that IL-1 acts primarily on resting B cells as a differentiation-inducing factor in the presence of antigen, and also acts as a 'priming' factor for TRF/IL-5.

Adjuvants, Immunologic↗
PubMedDate not supplied

Nitrite inhibition of Vitreoscilla hemoglobin (VHb) in recombinant E. coli: direct evidence that VHb enhances recombinant protein production.

Bacteria engineered with the gene (vgb) encoding Vitreoscilla hemoglobin (VHb) typically produce more protein than unengineered cells, and it has generally been assumed that VHb is responsible for this effect. Here, using matched strains of E. coli that bear a recombinant alpha-amylase gene (MK57) or the alpha-amylase gene and vgb (MK79), we provide evidence supporting this assumption. Sodium nitrite (which is known to inhibit heme proteins) was tested over a range of concentrations regarding effects on growth, alpha-amylase production, respiration, and VHb function in MK57 and MK79. Nitrite concentrations were identified at which respiration of cell membranes was inhibited only slightly and to approximately equal degrees in both strains, while whole cell respiration was inhibited to a greater extent and about twice as much in MK79 as MK57. This suggests that these concentrations inhibit VHb while having a much smaller effect on cytochrome oxidase. Direct measurements of VHb showed, in fact, that the same nitrite concentrations greatly decreased the levels of active (ferrous) and, to a somewhat lesser extent, total (ferrous plus ferric) VHb in MK79. Finally, these same nitrite concentrations reversed the advantage regarding alpha-amylase production of MK79 over MK57 seen at 0 mM nitrite, linking the presence of active VHb with the increase in alpha-amylase production.

Escherichia coli↗