• Bulletin of the Korean Chemical Society
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• 제22권12호
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• pp.1361-1365
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• 2001

Recombinant immunotoxins are hybrid cytotoxic proteins designed to selectively kill cancer cells. A divalent immunotoxins, [B3(FabH1)-PE38]2, was constructed by recombining Fab domain of B3 antibody as a cell-targeting domain and Pseudo monas exotoxin A (PE) as a cytotoxic domain. Monoclonal antibody, B3, is the murine antibody (IgG1k) directed against Lewis Y-related carbohydrate antigens, which are abundant on the surface of many carcinomas. Fab fragment of this antibody was used in this study with the modified hinge sequence where last two cysteines out of three were mutated to serine. PE is a 66 kDa bacterial toxin that kills eukaryotic cells by inhibiting protein synthesis with ADP ribosylation of ribosomal elongation factor 2 (EF2). Fc region of B3 antibody was substituted with the truncated form of PE (38 kDa, PE38) on DNA level. [B3(FabH1)-PE38]2 was formed by disulfide bond between cysteines in the modified hinge region of B3(FabH1)-PE38. Each polypeptide for recombinant immunotoxins was overexpressed in Escherichia coli and collected as inclusion bodies. Each inclusion body was solubilized and refolded, and cytotoxic effects were measured. Divalent immunotoxins, [B3(FabH1)-PE38]2, had ID50 values of about 10 ng/mL on A431 cell lines and about 4 ng/mL on CRL1739 cell lines. Control immunotoxins, B3(scFv)-PE40, had ID50 values of about 28 ng/mL on A431 cell lines and about 41 ng/mL on CRL1739 cell lines. Divalent immunotoxins, [B3(FabH1)-PE38]2, had higher cytotoxic effects than B3(scFv)-PE40 control immunotoxins.

• 약학회지
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• 제47권3호
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• pp.190-194
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• 2003

As previously reported, an immunoglobulin M (IgM) monoclonal antibody (MAb) B6.1, specific for a cell wall B-l,2-mannotriose, was protective against vaginal infection due to Candida albicans when mice were treated with the antibody. In this study, the role of neutrophil was examined in the protective effect of MAb B6.1 against vaginal infection. To deplete neutrophils, mice were given intravenously rat anti-mouse neutrophile MAb RB6-8C5 prior to intraperitoneal administration of MAb B6.1 to these mice. The mice were examined for antibody in their reproductive tract. By an ELISA, MAb B6.1 was found in the vaginal homogenates, but no antibody was detected in vaginal lavage materials. The neutropenia was induced by a single dose of the anti-neutrophil antibody, but lymphocytes were also partially depleted. The protective effect of MAb B6.1 was decreased when mice pretreated with MAb RB6-8C5 were given the anti-Candida antibody before challenge with C. albicans yeast cells intravaginally. These results show that neutrophils are involved in the MAb B6.1 protection against Candida vaginal infection.

• Clinical and Experimental Vaccine Research
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• 제12권2호
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• pp.116-120
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• 2023

Purpose: In Japan, the data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody titers after the booster dose of the coronavirus disease 2019 (COVID-19) vaccine are insufficient. The aim of this study is to evaluate changes in SARS-CoV-2 antibody titers before, 1, 3, and 6 months after the booster dose of the BNT162b2 COVID-19 vaccine among health care workers. Materials and Methods: A total of 268 participants who received the booster dose of the BNT162b2 vaccine were analyzed. SARS-CoV-2 antibody titers were measured before (baseline) and at 1, 3, and 6 months after the booster dose. Factors associated with changes in SARS-CoV-2 antibody titers at 1, 3, and 6 months were analyzed. Cutoff values at baseline were calculated to prevent infection of the omicron variant of COVID-19. Results: The SARS-CoV-2 antibody titers at baseline, and 1, 3, and 6 months were 1,018.3 AU/mL, 21,396.5 AU/mL, 13,704.6 AU/mL, and 8,155.6 AU/mL, respectively. Factors associated with changes in SARS-CoV-2 antibody titers at 1 month were age and SARS-CoV-2 antibody titers at baseline, whereas changes in SARS-CoV-2 antibody titers at 3 and 6 months were associated with the SARS-CoV-2 antibody titers at 1 month. The cutoff values of the SARS-CoV-2 antibody titers at baseline were 515.4 AU/mL and 13,602.7 AU/mL at baseline and 1 month after the booster dose, respectively. Conclusion: This study showed that SARS-CoV-2 antibody titers increase rapidly at 1 month after the booster dose of the BNT162b2 vaccine and begin to decrease from 1 to 6 months. Hence, another booster may be needed as soon as possible to prevent infection.

• BMB Reports
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• 제38권3호
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• pp.290-293
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• 2005

In order to investigate the epitope of basic fibroblast growth factor (bFGF) and its immunogenicity, the epitopes of bFGF were screened from the phage display library with monoclonal antibody GF22, which can neutralize the bio-activity of bFGF. By three rounds of screening, the positive phage clones with bFGF epitopes were selected, which can effectively block the bFGF to bind with GF22. Sequence analysis showed that the epitopes shared a highly conservative sequence (Leu-Pro-Pro/Leu-Gly-His-Phe/Ile-Lys). The sequence of PPGHFK was located at 22-27 of the bFGF. The specific immuno-response of mouse could be highly induced by phage clones with the epitopes. And the anti-bFGF activity induced by LPGHFK was 3 times higher than the original sequence, which showed that the mimetic peptide LPLGHIK might be used as a tumor vaccine in the prevention and treatment of tumor.

• Journal of Microbiology
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• 제45권6호
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• pp.528-533
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• 2007

In a previous study we generated an anti-Hepatitis B Virus (HBV) preS1 humanized antibody (HzKR127) that showed in vivo HBV-neutralizing activity in chimpanzees. However, the antigen-binding affinity of the humanized antibody may not be sufficient for clinical use and thus affinity maturation is required for better therapeutic efficacy. In this study, phage display technique was employed to increase the affinity of HzKR127. All six amino acid residues (Glu95-Tyr96-Asp97-Glu98-Ala99-Tyr100) in the heavy (H) chain complementary-determining region 3 (HCDR3) of HzKR127 were randomized and phage-displayed single chain Fv (scFv) library was constructed. After three rounds of panning, 12 different clones exhibiting higher antigen-binding activity than the wild type ScFv were selected and their antigen-binding specificity for the preS1 confirmed. Subsequently, five ScFv clones were converted to whole IgG and subjected to affinity determination. The results showed that two clones (B3 and A19) exhibited an approximately 6 fold higher affinities than that of HzKR127. The affinity-matured humanized antibodies may be useful in anti-HBV immunotherapy.

• 대한임상검사과학회지
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• 제50권3호
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• pp.354-358
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• 2018

수혈 준비 시 비예기 항체 선별검사를 통한 항체의 유무와 그 종류를 아는 것은 매우 중요하다. DiaMed-ID시스템을 이용하여 대전지역 일개 대학병원에 2016년 1월부터 2017년 12월까지 2년 동안 의뢰된 비예기 항체 선별검사 양성자 중에서 항체동정은 55명에서만 되었고 주로 여성에서 자주 동정되었다. Rh 36예(65.5%), Lewis 7예(12.7%), Kidd 4예(7.3%), Duffy 4예(7.3%), MNSs 3예(5.5%), Rh+Kidd 복합 1예(1.8%)가 동정되었는데, Rh 계열은 Anti-E 19예(34.5%), Anti-E/-c 4예(7.3%), Anti-C/-e 4예(7.3%), $Anti-E/-c/-Jk^b$ 1예(1.8%)가, Lewis 계열은 $Anti-Le^a$ 3예(5.5%), $Anti-Le^b$ 3예(5.5%), Kidd 계열은 $Anti-Jk^a$ 1예(1.8%), $Anti-Jk^b$ 3예(5.5%)가 동정되었다. Duffy와 MNSs 계열은 각각 $Anti-Fy^a$ 1예(1.8%), $Anti-Fy^b$ 3예(5.5%), Anti-M 2예(3.6%), Anti-S 1예(1.8%)가 동정되었다. 최근 대전의 비예기 항체 빈도와 분포가 반영된 이 연구는 효율적인 수혈준비에 도움이 될 것이다.

• 한국동물위생학회지
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• 제19권3호
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• pp.221-226
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• 1996

IBD's antibody level and morphological change of immune organ was examined in chicken. The results were as follows ; 1. Seventy percent at 42 day and 40% at 45 day of age chickens were reacted positively by the agar gel immunodiffusion test and 42 day and 45 day of age chickens indicated 1859, 1425 by the ELISA test, respectively. 2. In 2 and 5 day young broiler chickens, the level of maternal antibody was not proper. B/B ratio showed low level, but S/B ratio and BS were normal. 3. In layer, 100% of 8 and 86 day of age chicken and 70% at 40 day of age chicken had antibody aganist IBDV. The level of antibody was high as 2293 and 3336 in 8 and 86 day of age chicken, while was low as 1186 in 40 day of age chicken. B/B ratio showed low level and S/B ratio high level, but BS was normal.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.432-437
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• 2002

Immunosuppressive potential of 65 kDa buffalo placental protein (bPP65) on B-cell proliferation in vitro and antibody response in vivo was evaluated. B-cell proliferation was estimated by measuring incorporation of tritiated thymidine in buffalo lymphocytes while primary antibody responses against phytohaemagglutinin (PHA) or keyhole limpet haemocyanin (KLH) were evaluated in mice. bPP65 suppressed proliferation of lipopolysaccharide (a B-cell specific mitogen)-stimulated buffalo lymphocytes in vitro indicating suppression of B-cells. This suppression was dose dependent over the protein concentration range $25-100 {\mu}g/ml$. Primary antibody responses in mice against PHA and KLH in presence of bPP65 were lower as compared to in its absence but these were not statistically significant. Amino acid composition data of bPP65 and BSA suggested that bPP65 is different from BSA.

• 대한미생물학회지
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• 제6권1호
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• pp.29-40
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• 1971

Various kinds of antibiotics are generally believed to have inhibitory effects on the antibody response. However, as polymyxin B which belongs to the cyclic polypeptide group of antibiotic was found to have some enhancing effects on the antibody response of rabbits to enterobacterial common antigen(CA) under specified conditions, experiments were carried out on this problem with the following results. 1. When mixture of polymyxin B and CA derived from Salmonella typhimurium(STM) was treated 30 minutes at $37^{\circ}C$ and injected three times into rabbits by intravenous route, the antibody response to CA was weaker than rabbits injected CA only. 2. Mixture of polymyxin B and CA showed a marked antibody production when injected into rabbits primed with small amounts of heat-extracted antigen of STM, while the injection of CA alone showed low titers of response. 3. Mixture of polymyxin B and heat-extracted CA-containing antigen of Escherichia coli 014 also showed a increased antibody production than CA alone in rabbits primed with antigen of STM. 4. The effect of polymyxin B appeared in different ways. This antibiotic did not enhance the CA antibody response in rabbits primed with small amounts of E. coli 0111 and 055, but enhance in rabbits primed with Shigella flexneri. 5. No enhancing effect on the antibody response was observed by polymyxin B in rabbits primed with CA. 6. No enhancing effect on the antibody response was also noted in rabbits primed with STM antigen in case polymyxin B and CA were administered simultaneously but in veins of different places. 7. Bacitracin did not enhance the CA antibody response in primed rabbits with STM antigen, but neomycin slightly enhance the response. 8. Lipopolysaccharide showed no priming effect on the CA antibody response, and no enhancement of the CA antibody response in rabbits printed with STM. 9. The priming effect of STM antigen against CA antibody response was very weak as compared with the effect of CA derived from STM antigen.

• 대한미생물학회지
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• 제19권1호
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• pp.79-83
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• 1984

To determine the existence of anti-HLA antibodies finally in 220 human placental extracts to be proved negative antiserum by previous anti-HLA A,B,C antibody screening procedure, the present study was performed by fractionation of immunoglobulins using saturated ammonium sulfate and by simple batch method on DEAE cellulose. Thereafter using known 150 T-lymphocyte panels, complement-dependent microlymphocytotoxicity test was performed to observe the existence of anti-HLA antibodies and the degree of the antibody response of the concentrates. The following results were obtained: 1. Of total 141 placental sera concentrated 45 cases(31.9%) were showed significant anti-HLA A,B,C antibody response after concentration(Excellent, 19(13.5%), Good, 3(2.1%), Weak, 23(16.3%)). 2. Anti-HLA specificities of placental sera obtained after concentration were A2, A24, B13, B27, B44, B51, CN1, C7. 3. A new type C new-1 anti-HLA antibody that is only expressed in Korean people, was obtained. 4. 79 placental sera purrified by simple batch method using DEAE cellulose were showed negative anti-HLA antibody responses.