• KSBB Journal
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• 제24권3호
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• pp.246-252
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• 2009

본 연구에서는 형질전환된 벼 세포를 이용하여 자가면역 질환의 치료제인 human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig)을 생산하였고, RAmy3D promoter와 RAmy1A signal pertide를 사용하여 당 고갈시에 목적 단백질의 발현과 배지로의 분비를 유도하였다. 이 시스템의 문제점은 당 고갈에 의해 목적 단백질의 생산이 유도되기 때문에 에너지원이 없어 세포의 사멸, 이로 인한 배지내로의 protease 분비를 유발하게 된다. 이것은 목적 단백질의 안정성 저해와 궁극적으로는 생산성의 손실을 일으킨다. 따라서 세포를 보호하여 사멸을 막는 효과가 있음이 보고된 proline을 첨가하여 생산성 증진 효과를 확인하고자 하였다. 4 mM의 proline을 첨가하여 배양하였을 때, 세포의 사멸 및 pretense의 분비를 줄일 수 있었고 이는 결과적으로 hCTLA4Ig의 생산성 증진으로 이어졌다. 또한 단백질 안정제를 통하여 배지내로 분비된 hCTLA4Ig의 안정화를 이루어 생산성을 높이고자 하였다. 0.01 g/L의 gelatin을 적용하여 생산성 증진 효과를 확인하였으며, 이는 hCTLA4Ig의 안정화에 의한 것임을 알 수 있었다. Pretense의 분비를 줄이기 위한 세포 보호와 pretense의 공격을 막기 위한 hCTLA4Ig 보호를 통하여 형질전환된 벼 세포를 이용한 hCTLA4Ig의 안정성 및 생산성을 증대시킬 수 있음을 확인하였다.

• 생명과학회지
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• 제16권6호
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• pp.904-910
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• 2006

수지상세포는 종양면역에서 필수적인 강력한 CTL 반응을 개시할 수 있는 유일한 세포이다 . 특히 외인성 종양항원에 대한 CTL 반응 유도는 활성화된 수지상세포의 IL-12 분비를 통한 CD4+ helper T세포의 cross-priming을 필요로 한다. 그러나 최근에 활성화된 수지상세포는 $Th_1$ 면역반응을 유도하지만 활성화 시간이 경과함에 따라 오히려 $Th_2$반응을 유도 할 수 있다. 따라서 본 연구에서는 OVA를 종양항원 모델로 설정하여 종양특이적인 CTL 반응을 형성하기 위한 최적의 수지상세포 활성화 조건을 조사하였다. 마우스 골수세포에 서 수지상세포로의 분화는 항원제시 기능을 위한 표면분자의 발현 측면에서 볼 때 배양 6일-7일 정도가 적합하였다. 수지상세포의 IL-12 생성능은 배양 6일 이상, OVA 항원 탑재 8시간 이상의 경우에 연이은 LPS 성숙자극으로 오히려 감소하는 경향을 보였다. 즉 배양 6일의 수지상세포에 OVA 항원 탑재를 8시간 수행한 경우(8-h DC)가 in vitro에서의 IL-12생성능, ex vivo에서의 세포내 $IFN-{\gamma}$를 발현하는 CD8+ T세포의 증가 및 OVA 특이적인 세포독성효과 등에서 가장 좋은 결과를 보였다. 또한 in vivo에서 종양 치료 및 예방효과에서도 8-h DC로 면역한 경우에 가장 우수한 종양형성 억제 효과와 생존기간 연장효과를 보였다. 현재 대부분의 수지상 세포를 이용한 항종양 백신에서 항원 탑재반응을 24시간 동안 수행하고 있으나, 본 실험의 결과로 볼 때, 8시간의 in vitro 항원 탑재가 보다 효과적인 종양특이적 CTL 반응과 항종양 면역반응을 유도함을 알 수 있다. 결론적으로 본 연구를 통하여 8시간 이상의 항원접촉은 수지상세포의 기능적 활성능력을 오히려 고갈시킬 수 있음을 제시한다.

• 대한수의학회지
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• 제34권2호
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• pp.287-299
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• 1994

Plasma protein which has been known as one of nonspecific immunostimulators was added to feedstuff to examine its effect on the enhancement of cellular immune response in porcine immune system. A total of 40 piglets, 20 male and 20 female each, were fed for 30 days with or without plasma protein. The peripheral blood were collected and analyzed for the investigation of leukocyte subpopulations and their activities by using a panel of monoclonal antibodies specific to porcine leukocyte differentiation antigens and flow cytometry. The results obtained as follows. 1. Subpopulations expressing major histocompatibility complex(MHC) class I antigen were $96.2{\pm}3.1%$ and $86.6{\pm}3.8%$ in piglets fed with plasma protein and in piglets fed without plasma protein, respectively. 2. Proportion of leukocyte subpopulation expressing MHC class II antigens were significantly higher in the piglets fed with plasma protein than ones without plasma protein. The proportion was $27.6{\pm}3.6%$ and $16.6{\pm}2.2%$ in MHC class II DQ antigen, and $28.1{\pm}2.0%$ and $20.0{\pm}0.3%$ in MHC class II DR antigen, respectively. 3. A significant increase in the proportion of cells expressing poCD2 was not found in piglets fed plasma protein. 4. Proportion of subpopulation expressed porcine(Po) CD4 antigens which specific to helper T lymphocytes were not increased (18.3-19.1% vs. 25.6-28.8%), rather slightly decreased, in plasma protein-treated group. 5. The most important increase of proportion in plasma protein-treated group was the leukocyte subpopulation specific to $poCD8^+$ T cytotoxic/suppressor lymphocytes. The expression level was significantly higher up to 45.9-47.1% in plasma protein-treated group in comparing with 29.7-33.0% in non-plasma protein-treated group. 6. Lymphoblastogenetic responses using different concentrations of Con A mitogen and plasma protein has found that the responses of lymphocyte from piglets fed plasma protein was significantly activated (p<0.01). The activities measured by 3[H]-thymidine incorporation showed 3-6 times stronger in plasma protein-treated group than those in non-plasma protein-treated group. The study has concluded that plasma protein, which has known as a nonspecific immunostimulator, may have an immunoenhancing activities in porcine lymphoid system by increase the activated cell proportions and their blastogenetic properties which is critical to host immune responses.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1944-1948
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• 2007

Silkworm hemolymph (SH), prepared from fifth-instar larvae of Bombyx mori and heat-treated at $60^{\circ}C$ for 30 min, was used to improve cell viability and the production of human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) in transgenic Oryza sativa L. cell suspension cultures. Even though SH could not elevate cell viability at the concentrations up to 3% (v/v), addition of 0.3% (v/v) SH to a culture medium enhanced the production of hCTLA4Ig by 36.8% over an SH-free medium. Moreover, the production period of hCTLA4Ig could be shortened in a 0.3% (v/v) SH-added medium compared with that in an SH-free culture. As a result, addition of 0.3% (v/v) SH improved the productivity of hCTLA4Ig significantly in transgenic rice cell cultures.

• 생물정신의학
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• 제10권1호
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• pp.80-84
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• 2003

Objective : Bipolar disorder is known to have strong genetic background and cellular immune activation. Based on the hypothesis that abnormalities of normal inhibitory control of T cell immunity can contribute to the pathophysiology of bipolar disorder, we investigated the relationship between the first exon at position +49(A/G) polymorphism of cytotoxic T lymphocyte antigen 4(CTLA4) gene and bipolar disorder. Method : Among the Korean patients diagnosed as bipolar disorder according to DSM-IV, 90 patients without serious medical illness, neurologic illness, hormonal disorder, or concomitant mental illness were selected. The normal control group consisted of 149 age-and sex-matched subjects without current or past history of autoimmune diseases or mental disorder. DNA was extracted from whole blood and the exon 1 region of CTLA-4 gene was amplified by polymerase chain reaction. Gene typing was performed using single strand conformation polymorphism. Results : There were no significant differences in genotype frequencies of G/G, G/A, and A/A between the patients with bipolar disorder and the control group(48.9% vs 46.3%, 44.4% vs 39.6%, and 6.7% vs 14.1%, respectively). There were no significant differences in allelic frequencies of G and A between the patients with bipolar disorder and the control group(71.1% vs 66.1%, and 28.9% vs 33.9%, respectively). Conclusion : This study did not show the association of exon 1 polymorphism of CTLA-4 gene with bipolar disorder.

• Tuberculosis and Respiratory Diseases
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• 제42권6호
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• pp.823-830
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• 1995

연구배경: 결핵감염시 세포매개성 면역반응이 관여하여 말초혈액내 조력 T 세포가 감소하는 것으로 알려저왔다. 그러나 말초혈액내 표지물질을 가진 세포의 수적 감소가 세포매개성 면연반응의 저하라고 할 수있지 여부가 앞으로 해결해야 될 문제인 것으로 지적되고 있다. 이에 저자들은 폐결핵 환자들의 말초혈액에서 활성화된, 또는 활성화 되고 있은 세포의 수적변화를 관찰하기 위하여 본 연구를 시행하였다. 방법: 객담 결핵균 양성인 폐결핵 환자 22명을 대상으로 말초혈액에서 IL-2R, VLA-1, TLiSAI의 활성화 표지에 대한 단세포군 항체를 면역조직 화학법으로 측정하였다. 결과: 1) 폐결핵 환자의 말포혈액에서 $T_1$(+) 세포 및 그 아형들의 단위 부피당 절대수는 $T_4$(+) 세포는 유의하게 감소하였고 $T_8$(+) 세포는 증가하였다(p<0.05). 2) 폐결핵 환자에서 전체 T임파구의 비율은 감소되어 있으며 $T_4$(+) 세포, $T_8$(+) 세포비율은 각각 유의하게 감소, 증가하였다. 또한 $T_4(+)/T_8(+)$ 비율도 유의한 감소가 있었다(p<0.05). 3) 폐결핵 환자에서 activated T cell의 단위 부피당 절대수는 대조군에 비해 모두 유의한 증가를 보였다(p<0.05). 4) 폐결핵 환자에서 activated T cell 비율은, IL-2R, VLA-1, TLiSAI, 각각 6.45+1.56%, 7.64+1.34%, 10.45+1.16%로 모두 대조군에 비해 모두 유의한 증가를 보이며 특히 TLiSAI 항체가 가장 많이 관찰 되었다. 결론: 폐결핵 감염시 말초혈액 임파구의 일부만이 활성화되어 세포매개성 면역반응에 참여하는 것으로 사료된다.

• 한국임상약학회지
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• 제28권1호
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• pp.65-75
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• 2018

Objective: Over the last several years, immunotherapy has become one of the most promising therapeutic options for cancer. This study aims to summarize the updates on cancer immunotherapy focusing on immune checkpoint inhibitors, such as programmed cell death-1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitors, which have received attention as new anticancer therapeutic agents. Methods: A literature survey was carried out on PubMed to identify high-impact papers on cancer immunotherapy from 2010. The most recent data on clinical efficacy and safety have been included highlighting the response characteristics to recently approved immunotherapeutic agents. Results: In various cancers, immune checkpoints are a means for cancer cells to evade the immune system. Furthermore, CTLA-4 and PD-L1 can be overexpressed, allowing malignant cells to evade T-cells. Numerous clinical trials have been performed to seek appropriate indication of these products in various cancer types. Among them, the most conspicuous types are melanoma, non-small-cell lung cancer, and head and neck cancer. The approval of ipilimumab by Food and Drug Administration (FDA) commenced a new era of cancer immunotherapy. This was followed by the approval of nivolumab and pembrolizumab. Currently, combination therapies are being investigated for various cancer types. Conclusion: In this study, we reviewed recently reported scientific and clinical evidence for currently approved immune checkpoint inhibitors. Although these novel checkpoint inhibitors are ever evolving for cancer therapies, there exist limitations that need to be overcome, indicating the necessity for further studies aiming to improve their efficacy, toxicity, and cost.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.304-316
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• 2021

Vaccination is the most effective way to prevent influenza virus infections. However, conventional vaccines based on hemagglutinin (HA) have to be annually updated because the HA of influenza viruses constantly mutates. In this study, we produced a 3M2e-3HA2-NP chimeric protein as a vaccine antigen candidate using an Escherichia coli expression system. The vaccination of chimeric protein (15 ㎍) conferred complete protection against A/Puerto Rico/8/1934 (H1N1; PR8) in mice. It strongly induced influenza virus-specific antibody responses, cytotoxic T lymphocyte activity, and antibody-dependent cellular cytotoxicity. To spare the dose and enhance the cross-reactivity of the chimeric, we used a complex of poly-γ-glutamic acid and alum (PGA/alum) as an adjuvant. PGA/alum-adjuvanted, low-dose chimeric protein (1 or 5 ㎍) exhibited higher cross-protective effects against influenza A viruses (PR8, CA04, and H3N2) compared with those of chimeric alone or alum-adjuvanted proteins in vaccinated mice. Moreover, the depletion of CD4+ T, CD8+ T, and NK cells reduced the survival rate and efficacy of the PGA/alum-adjuvanted chimeric protein. Collectively, the vaccination of PGA/alum-adjuvanted chimeric protein induced strong protection efficacy against homologous and heterologous influenza viruses in mice, which suggests that it may be a promising universal influenza vaccine candidate.

• KSBB Journal
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• 제31권4호
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• pp.284-290
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• 2016

In this research, recombinant human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) was produced by transgenic rice cells. RAmy3D promoter was used for overcome the limitation of low expression level in transgenic plant cells, and the secretion of target protein was accomplished by signal peptide. However, the RAmy3D promoter system which can be induced only by sugar starvation causes the decrease of cell viability. As a result, cell death promotes the release of protease which degrades the target proteins. The protein stability and productivity can be significantly influenced by proteolysis activity. Therefore, development of new strategies are necessary for the in situ recovery of target proteins from cell culture media. In this study, in situ recovery was performed by various strategies. Direct addition of Protein A resin with nylon bag leads to cell death by increased shear stress and decrease in production of hCTLA4Ig by protease. Medium exchange through modified flask could recover hCTLA4Ig with high cell viability and low protease activity, on the other hand, the productivity was lower than that of control. When in situ recovery was conducted at day 7 after induction in air-lift bioreactor, 1.94-fold of hCTLA4Ig could be recovered compared to control culture without in situ recovery. Consequently, in situ recovery of hCTLA4Ig from transgenic rice cell culture could enhance productivity significantly and prevent degradation of target proteins effectively.

• KSBB Journal
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• 제28권4호
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• pp.260-268
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• 2013

Transgenic plant cell cultures are an attractive expression system for the production of industrial and pharmaceutical proteins because of their advantages in safety and low production cost. Human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) was produced and secreted when sugar was depleted in culture medium by transgenic rice cell lines (Oryza sativa L.) using RAmy3D promoter. Due to the production of the target protein by sugar depletion, concomitant occurrence of cell death is inevitable. For that reason, inhibition of cell death for enhancing productivity was necessary for the production period without energy sources. Supplementation of 0.1 mM sodium nitroprusside improved cell viability by 1.4-fold and maximum hCTLA4Ig production by 1.3-fold compared to those of control. Addition of 1 and 10 mM glutathione, N-acetylcysteine (NAC), and nicotinamide inhibited apoptotic-like programmed cell death by decreasing the activity of reactive oxygen species. Production hCTLA4Ig was enhanced 1.4-, 1.25-, and 1.15-fold with 10 mM NAC, 1 mM NAC, and 1 mM glutathione, respectively. In addition, it was found that the supplementation of NAC enhanced the cell viability.