항체 : 치료제로서의 부활

정홍근,정준호,Chung, Hong Keun,Chung, Junho 대한면역학회 2001 Immune Network Vol.1 No.1

Currently 18 monoclonal antibodies were approved by FDA for inj ection into humans for therapeutic or diagnostic purpose. And 146 clinical trials are under way to evaluate the efficacy of monoclonal antibodies as anti-cancer agents, which comprise 9 % of clinical trials in cancer therapy field. When considering a lot of disappointment and worries existed in this field during the past 15 years, this boom could be called as resurrection. Antibodies have several merits over small molecule drug. First of all it is easier and faster in development, as proper immunization of the target proteins usually raises good antibody response. The side effects of antibodies are more likely to be checked out in immunohistomchemical staining of whole human tissues. Antibody has better pharmacokinetics, which means a longer half-life. And it is non-toxic as it is purely a "natural drug. Vast array of methods was developed to get the recombinant antibodies to be used as drug. The mice with human immunoglobulin genes were generated. Fully human antibodies can be developed in fast and easy way from these mice through immunization. These mice could make even human monoclonal antibodies against any human antigen like albumin. The concept of combinatorial library was also actively adopted for this purpose. Specific antibodies can be screened out from phage, mRNA, ribosomal library displaying recombinant antibodies like single chain Fvs or Fabs. Then the coding genes of these specific antibodies are obtained from the selected protein-gene units, and used for industrial scale production. Both $na\ddot{i}ve$ and immunized libraries are proved to be effective for this purpose. In post-map arena, antibodies are receiving another spotlight as molecular probes against numerous targets screened out from functional genomics or proteomics. Actually many of these antibodies used for this purpose are already human ones. Through alliance of these two actively growing research areas, antibody would play a central role in target discovery and drug development.

위암조직에서 종양관련항원 TAG - 72와 CEA의 농도 및 분포

정준기,이명철,정홍근,고창순,임상무,장자준 ( June Key Chung,Myung Chul Lee,Hong Keun Chung,Chang Soon Koh,Sang Moo Lim,Ja Joon Jang ) 대한핵의학회 1992 핵의학 분자영상 Vol.26 No.2

악성종양에서 골수면역신티그라피를 이용한 골수전이의 평가 : $^{99m}Tc$-MDP 뼈스캔과의 비교

이경한,최창운,방영주,정준기,정홍근,이명철,김병국,김노경,고창순,Lee, Kyung-Han,Choi, Chang-Woon,Bang, Yung-Jue,Chung, Jun-Key,Chung, Hong-Keun,Lee, Myoung-Chul,Kim, Byoung-Kook,Kim, Noe-Kyeong,Koh, Chang-Soon 대한핵의학회 1994 핵의학 분자영상 Vol.28 No.1

Although bone scan is a highly sensitive test for detecting bone metastasis, its findings are often limited in specificity and cannot be used for assessing the bone marrow. Bone marrow scintigraphy may provide useful information but previous experience with radiolabelled colloid has been disappointing. Recently, $^{99m}Tc$ labeled anti-granulocyte monoclonal antibody (anti-NCA-95 MAb) has been introduced as a new bone marrow imaging agent. To evaluate the usefulness of $^{99m}Tc$ anti-NCA MAb bone marrow scans for detecting skeletal metastasis, bone marrow scans of 44 malignant tumor patients were evaluated and compared with bone scan findings. Bone scan showed abnormal lesions in 26(59%) cases, and 18 of these patients also had an abnormal bone marrow scan. Seven of the 8 patients who had normal bone marrow scan despite bone scan lesions were confirmed to be free from metastasis. There was one case with a marrow defect despite normal bone scan but the presence of metastasis was not determined due to loss of follow up. Bone scan demonstrated a total of 64 lesions while bone marrow scan showed 38 lesions. Fifty percent (32/64) of the bone scan lesions had matching marrow defects while the remaining 50% did not. Most of these non matched lesions were suggested to be nonspecific lesions such as rib fractures or degenerative change. Meanwhile bone marrow scan was able to detect 6 new lesions not detected by bone scan, bit metastasis in each lesion was not confirmed. Bone marrow scan was also helpful in assessing equivocal bone scan lesions to be of metastatic nature in 10 patients by demonstrating a matched marrow defect. Thus $^{99m}Tc$ anti-NCA MAb bone marrow scan can help exclude metastasis in patients with nonspecific bone scan lesions and may be able to detect metastatic lesions not seen with bone scan. It appears useful as a complementary study to bone scan in evaluating malignant tumor patients.

99mTC 표지 향과립구단일클론항체를 이용한 골수신티그라피법의 개발

최창운(Chang Woon Choi),정준기(June Key Chung),이명철(Myung Chul Lee),김병국(Byung Kook Kim),고창순(Chang Soon Koh),정홍근(Hong Keun Chung) 대한내과학회 1994 대한내과학회지 Vol.46 No.1

N/A Objectives: The purpose of the present study was to determine the immunologic characteristics of a home made anti-CEA monoclonal antibody (MAB) called CEA-79 which was considered to bind with the epitope of nonspecific cross-reacting antigen (NCA) in human granulocytes, and to evaluate the potential of 99mmTc- labeled CEA-79 as an immunoscintigraphic agent for bone marrow imaging. Methods: In order to evaluate the immunologic characteristics of this MAb, western blotting and immunohistochemical staining were performed. Periph eral blood smears of 6normals and bone marrow aspirates of 3normals, 12leukemic patients, and 1multiple myeloma patient were immunohistochemically stained by the alkaline phosphatase anti-alkaline phosphatase method. CEA-79 MAbs were labeled with 99mmTc by a transchelation method using β-mercaptoethanol as a reducing agent and glucarate as a chelator. With this 99mmTc-labeled CEA-79, scatchard analysis for affinity constant, immunoreactivity test and in vitro stability studies were performed. Formazan test was done for the evaluation of effect of CEA-79 to superoxide formation of granulocytes. Results: Western blotting of human granulocyte extracts with the MAb showed a single band at a site equivalent to a molecular weight of 95,000 daltons, suggesting that the binding was with an epitope of the NCA-95. Positive staining with CEA-79 antibody was shown in 93% of the peripheral granulocytes. Positively stained cells were derived from promyelocytes, myelocytes, metamyelocytes, band forms and segment forms. Erythroblasts of all maturation stages and normal lymphocytes were not stained. Leukemic blasts from patients with ALL, and Ml, M2, M5 subtypes of AML were also not stained. With a direct labeling method by transchelation of 99mmTc, the labeling efficiency of CEA-79 MAb with 99mmTc was 60 to 85%. Scatchard analysis of the MAb with granulocytes yielded an affinity constant of 1.10 to 4,75±10(10) 1/mol. Immunoreactivity was 60~65% which was similar to that of 131 I -labeled monoclonal antibodies prepared by the chloramine-T method(60%). The antibody was stable for 24 hours, with over 90% of the MAb remaining labeled at 24hours. And CEA-79 antibody did not change the granulocyte function of superoxide formation. Conclusion: It can be concluded that CEA-79 reacts specifically with an epitope of NCA-95 on human granulocytes and can be successfully labeled with 99mmTc by a direct labeling method. This indicates that 99mmTc-labeled CEA-79 MAb may be useful as an immunoscintigraphic agent for bone marrow imaging.

항 암태아성항원에 대한 단세포군항체의 99mTc 표지법개발 및 생체분포

고창순(Chang Soon Koh),이명철(Myung Chul Lee),정준기(Jung Key Chung),문대혁(Dae Hyuk Moon),박재갑(Jae Gahb Park),정홍근(Hong Keun Chung) 대한핵의학회 1992 핵의학 분자영상 Vol.26 No.2

N/A This study was designed to evaluate a direct method of Tc-99m labeling using β- mercaptoethanol as a reducing agent, and to investigate whether Tc-99m labeled specific monoclonal antibody against carcinoembryonic antigen (CEA-92) can be used for the scintigraphic localization of human colon cancer xenograft. Purified CEA-92 IgG was fragmented into F(ab')2 and then labeled with Tc-99m by transchelation method using glucarate as a chelator. Labeling efficiency, immunological reactivity and in vitro stability of Tc-99m CEA-92 F(ab')2 were measured and then injected intravenously into nude mice bearing human colon cancer (SNU-C4). Scintigrams were obtained at 24 hour after injection. Then nude mice were sacrificed and the radioactivity was measured. Labeling efficiency of injected Tc-99m CEA-92 F(ab')2, immunoreative fraction and in vitro stability at 24 hour of injected Tc-99m CEA-92 F(ab')2 was 45.2%, 32.8% and 57.4%, respectively. At 24 hour after injection, % ID/g in kidney (46.77) showed high uptake, but %ID/g in tumor (1.65) was significantly higher than spleen (0.69), muscle (0.16), intestine (0.45), stomach (0.75), heart (0.48) and blood(0.45). There was no significant difference between tumor and liver (1.81). Tumor contrast as quantitated by tumor to blood ratio of Tc-99m CEA-92 F(ab')2 was increased significantly (p〈(0.005) until 24 hours (3.70), and there was no statistical difference from tumor to blood ratio of I-131 CEA-92 F(ab')2. The scintigram demonstrated localization of radioactivity over transplanted tumor, but significant background radioactivity was also noted over kidney and abdomen. It is concluded that CEA-92 F(ab')2 can be labeled with Tc-99m by a direct transchelation method using β-mercaptoethanol as a reducing agent and Tc-99m labeled CEA-92 F(ab') can be used for the scintigraphic localization of human colon cancer xenograft in nude mice model.

동위원소 표지 단세포군항체의 면역반응성과 방사면역계수법의 예민도 : 표지방법 및 비방사능이 미치는 영향

문대혁(Dae Hyuk Moon),이명혜(Myung Hae Lee),류진숙(Jin Sook Ryu),정홍근(Hong Keun Chung),천준홍(Jun Hong Cheon) 대한핵의학회 1993 핵의학 분자영상 Vol.27 No.2

한선종양에 대한 면역조직화학적 연구

성경제(Kyung Jeh Sung),조광현(Kwang Hyun Cho),정홍근(Hong Keun Chung),김성범(Sung Bum Kim),최지호(Jee Ho Choi),고재경(Jai Kyoung Koh) 대한피부과학회 1992 대한피부과학회지 Vol.30 No.3

The histogenesis and differentiation of sweat gland tumors are controversial. Twenty-two cases of sweat gland tumors were stained by immunoperoxidase technique (ABC method) for the presence of S-100 protein, CEA, and two kinds of keratin. Four syringomas, 4 eccrine poromas, 2 eccrine porocarcinomas, 2 eccrine spiradenomas, 1 papillary eccrine adenoma, 3 clear cell hidradenomas, 3 mixed tumors of skin, 2 papillary syringocystadenomas, and 1 cylindroma were included. All samples were formalin-fixed and paraffin-erribedded. Two monoclonal cytokeratin ant.ibodies, MA-902 (specific for cytokeratin No. 8) and MA-903 (specific for cytokeratins No.1,5,10,11) were used. In normal eccrine and apocrine glands, MA-902 stains cells of the intradermal duct and secretory portion. While MA-903 stains cells of the intraepidermal and intradermal duct and myoepithelial cells of eccine and apocrine glands, S-100 protein is found in the secretory cells of the intradermalduct and secretory portion, while CEA stains the secretory and ductal cells of eccrine and apocrine glands. All sweat gland tumors we studied stained by 4 antibodies in variable positive rates, Based on these findings, we discuss the histogenesis of various sweat gland tumors. (Kor J Dermatol 1992; 30(3): 303-316)

면역크로마토그래피법을 이용한 B형간염 진단용 kit의 개발

신형순(Hyeong-Soon Shin),신광순(Kwang-Soon Shin),정홍근(Hong-Keun Chung),허태련(Tae-Ryeon Heo) 한국생물공학회 2000 KSBB Journal Vol.15 No.2

국산 항 CEA 항체의 I - 131 , Tc - 99m 표지법 확립 및 면역학적 특성 분석

고창순(Chang Soon Koh),이명철(Myung Chul Lee),정준기(June Key Chung),이동수(Dong Soo Lee),홍미경(Mee Kyoung Hong),최석례(Seok Rye Choi),서일택(Il Taek Seo),정홍근(Hong Keun Chung),정준호(Jun Ho Chung) 대한핵의학회 1992 핵의학 분자영상 Vol.26 No.2

N/A Caneer cells have several tumor-associated antigens on the cell surfaces, and antibodies against these antigens have been developed by many investigators. Radiolabeled antibodies have been used as new methods to diagnose and treat malignant tumors. Especially anti- carcinoembryonic antigen (CEA) is the most popular antibody for these purposes. In this investigation, we tried to label 131I and Tc-99m to anti-CEA monoclonal antibodies which were developed in the Seoul National University College of Medicine. We found CEA-79 and CEA-92 antibodies had the better immunological characteristics among 8 anti-CEA monoclonal antibodies. And radioiodination of CEA-79 could be performed by chloramine-T method, while radioiodination of CEA-92 by iodogen method. To label these antibodies with Tc-99m, we used pretargeting transchelation as direct labeling method. At first, Tc-99m was bound to glucaric acid, and monoclonal antibody was reduced by β-mercaptoethanol. When these were incubated together, Tc -99m bound to glucarate was switched to monoclonal antibody because of higher affinity. We established conditions of several steps in this method. Anti-CEA monoclonal antibodies labeled with 131I and Tc-99m are expected to be used valuably in the detection and treatment of malignant tumors.

악성종양에서 골수면역신티그라피를 이용한 골수전이의 평가 : 99mTc-MDP 뼈스캔과의 비교

고창순(Chang Soon Koh),김노경(Noe Kyeong Kim),김병국(Byoung Kook Kim),최창운(Chang Woon Choi),정준기(Jun Key Chung),방영주(Yung Jue Bang),이경한(Kyung Han Lee),정홍근(Hong Keun Chung),이명철(Myoung Chul Lee) 대한핵의학회 1994 핵의학 분자영상 Vol.28 No.1

N/A Although bone scan is a highly sensitive test for detecting bone metastasis, its findings are often limited in specificity and cannot be used for assessing the bone marrow. Bone marrow scintigraphy may provide useful information but previous experience with radiolabelled colloid has been disappointing. Recently, 99mTc labeled anti-granulocyte rnonoclonal antibody (anti-NCA-95 MAb) has been introdueed as a new bone marrow imaging agent. To evaluate the usefulness of 99mTc anti-NCA MAb bone marrow scans for detecting skeietal metastasis, bone marrow scans of 44 malignant tumor patients were evaluated and compared with bone scan fmdings. Bone scan showed abnormal lesions in 26(59%) cases, and 18 of these patients also had an abnormal bone marrow scan. Seven of the 8 patients who had normal bone marrow scan despite bone scan lesions were confirmed to be free from metastasis. There was one case with a marrow defect despite normal bone scan but the presence of metastasis was not determined due to loss of follow up. Bone scan demonstrated a total of 64 lesions while bone marrow scan showed 38 lesions. Fifty percent (32/64) of the bone scan lesions had matching marrow defects while the rernaining 50% did not. Most of these non matched lesions were suggested to be nonspecific 1esions such as rib fractures or degenerative change. Meanwhile bone marrow scan was able to detect 6 new lesions not detected by bone scan, but metastasis in each lesion was not confirmed. Bone marrow scan was also helpful in assessing equivocal bone scan lesions to be of metastatic nature in 10 patients by demonstrating a matched marrow defect. Thus 99mTc anti-NCA MAb bone marrow scan can help exclude metastasis in patients with nonspecific bone scan lesions and may be able to detect metastatic lesions not seen with bone scan. It appears useful as a complementary study to bone scan in evaluating malignant tumor patients.