• Title/Summary/Keyword: Challenge-response

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Comparison of immunoadjuvant activities of four bursal peptides combined with H9N2 avian influenza virus vaccine

  • Zhang, Cong;Zhou, Jiangfei;Liu, Zhixin;Liu, Yongqing;Cai, Kairui;Shen, Tengfei;Liao, Chengshui;Wang, Chen
    • Journal of Veterinary Science
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    • v.19 no.6
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    • pp.817-826
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    • 2018
  • The bursa of Fabricius (BF) is a central humoral immune organ unique to birds. Four bursal peptides (BP-I, BP-II, BP-III, and BP-IV) have been isolated and identified from the BF. In this study, the immunoadjuvant activities of BPs I to IV were examined in mice immunized with H9N2 avian influenza virus (AIV) vaccine. The results suggested that BP-I effectively enhanced cell-mediated immune responses, increased the secretion of Th1 (interferon gamma)- and Th2 (interleukin-4)-type cytokines, and induced an improved cytotoxic T-lymphocyte (CTL) response to the H9N2 virus. BP-II mainly elevated specific antibody production, especially neutralizing antibodies, and increased Th1- and Th2-type cytokine secretion. BP-III had no significant effect on antibody production or cell-mediated immune responses compared to those in the control group. A strong immune response at both the humoral and cellular levels was induced by BP-IV. Furthermore, a virus challenge experiment followed by H&E staining revealed that BP-I and BP-II promoted removal of the virus and conferred protection in mouse lungs. BP-IV significantly reduced viral titers and histopathological changes and contributed to protection against H9N2 AIV challenge in mouse lungs. This study further elucidated the immunoadjuvant activities of BPs I to IV, providing a novel insight into immunoadjuvants for use in vaccine design.

Isolation and Characterization of Pathogen-Inducible Putative Zinc Finger DNA Binding Protein from Hot Pepper Capsicum annuum L.

  • Oh, Sang-Keun;Park, Jeong-Mee;Jung, Young-Hee;Lee, Sanghyeob;Kim, Soo-Yong;Eunsook Chung;Yi, So-Young;Kim, Young-Cheol;Seung, Eun-Soo
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.79.2-80
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    • 2003
  • To better understand plant defense responses against pathogen attack, we identified the transcription factor-encoding genes in the hot pepper Capsicum annuum that show altered expression patterns during the hypersensitive response raised by challenge with bacterial pathogens. One of these genes, Ca1244, was characterized further. This gene encodes a plant-specific Type IIIA - zinc finger protein that contains two Cys$_2$His$_2$zinc fingers. Ca1244 expression is rapidly and specifically induced when pepper plants are challenged with bacterial pathogens to which they are resistant. In contrast, challenge with a pathogen to which the plants are susceptible only generates weak Ca1244 expression. Ca1244 expression is also strongly induced in pepper leaves by the exogenous application of ethephon, an ethylene releasing compound. Whereas, salicylic acid and methyl jasmonate had moderate effects. Pepper protoplasts expressing a Ca1244-smGFP fusion protein showed Ca1244 localizes in the nucleus. Transgenic tobacco plants overexpressing Ca1244 driven by the CaMV 355 promoter show increased resistance to challenge with a tobacco-specific bacterial pathogen. These plants also showed constitutive upregulation of the expression of multiple defense-related genes. These observations provide the first evidence that an Type IIIA - zinc finger protein, Ca1244, plays a crucial role in the activation of the pathogen defense response in plants.

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Dietary Supplementation of Betaine (Betafin) and Response to High Temperature Stress in Male Broiler Chickens

  • Zulkifli, I.;Mysahra, S.A.;Jin, L.Z.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.2
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    • pp.244-249
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    • 2004
  • The effects of supplemental betaine ($Betafin^{(R)}$) in the drinking water (50 g/kg) (WB) or feed (100 g/kg) (FB) were investigated on male broiler chickens ($Cobb{\times}Cobb$) exposed to 4 h episodes of heat stress at $34{\pm}1^{\circ}C$ on day (d) 35 and $36{\pm}1^{\circ}C$ from d 36 to 41. Prior to (d 1 to 34) and following heat exposure (d 35 to 41), betaine supplementation had no significant effect on body weight, total feed intake and cumulative feed conversion ratios of broilers. The total water intake of WB chicks was lower compared to controls. Prior to heat exposure, there was no difference in percentage of mortality among the three dietary groups. Following the heat challenge period, although higher percentage of control chicks succumbed to the heat challenge as compared to those of WB, it was not significantly different. The WB and FB chicks were less hyperthermic than controls in response to the heat challenge. Irrespective of treatment groups, the heat treatment resulted in a marked elevation in heterophil/lymphocyte ratios (HLR). The WB birds, however, had smaller increase in HLR than those of controls during heat exposure. Antibody production against Newcastle disease vaccine on day 35 was not affected by betaine supplementation. On d 42, WB birds had higher antibody production than those of FB. It is concluded that the WB treatment, as measured by HLR, antibody production and mortality rate, has advantages over the FB group under heat stress conditions.

Switched SRAM-Based Physical Unclonable Function with Multiple Challenge to Response Pairs (스위칭 회로를 이용한 다수의 입출력 쌍을 갖는 SRAM 기반 물리적 복제 불가능 보안회로)

  • Baek, Seungbum;Hong, Jong-Phil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.8
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    • pp.1037-1043
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    • 2020
  • This paper presents a new Physical Unclonable Function (PUF) security chip based on a low-cost, small-area, and low-power semiconductor process for IoT devices. The proposed security circuit has multiple challenge-to-response pairs (CRP) by adding the switching circuit to the cross-coupled path between two inverters of the SRAM structure and applying the challenge input. As a result, the proposed structure has multiple CRPs while maintaining the advantages of fast operating speed and small area per bit of the conventional SRAM based PUF security chip. In order to verify the performance, the proposed switched SRAM based PUF security chip with a core area of 0.095㎟ was implemented in a 180nm CMOS process. The measurement results of the implemented PUF show 4096-bit number of CRPs, intra-chip Hamming Distance (HD) of 0, and inter-chip HD of 0.4052.

An RFID Authentication Protocol based Symmetric Key using Hashed Tag ID (해쉬된 태그ID와 대칭키 기반의 RFID 인증프로토콜)

  • Park, Yong-Soo;Shin, Ju-Seok;Choi, Myung-Sil;Chung, Kyung-Ho;Ahn, Kwang-Seon
    • The KIPS Transactions:PartC
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    • v.16C no.6
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    • pp.669-680
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    • 2009
  • By identifying the unique information of the objects using the RF, the RFID technique which will be able to manage the object is spot-lighted as the main technology in Ubiquitous era. On RFID systems, since the information of RFID may easily be unveiled in air, the secure and privacy problems always exist. In this paper, we propose mutual authentication protocol based on symmetric key. Proposed protocol has been able to minimize the tag's H/W resource by using symmetric key. And we use tag ID which is encrypted with hash function and a shared symmetric key by Challenge-Response pair of PUF(Physically Unclonable Function), thus there is no key disclosure problem in our protocol.

A Study on Intensified scheme to WLAN Secure based on IEEE 802.1x Framework (IEEE 802.1x 프레임워크 기반에서의 무선랜 보안 강화 방안에 관한 연구)

  • Lee Joon;Hong Seong-pyo;Shin Myeong-sook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.1
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    • pp.136-141
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    • 2006
  • The IEEE 802.1x can be using various user authentication mechanisms: One-Time Password, Certificate-Based TLS, Challenge/Response and Keberos through EAP(Extended Authentication Protocol). But, IEEE 802.1x also has vulnerabilities about the DoS, the session hijacking and the Man in the Middle attack due to the absence of AP authentication. In this paper, we propose a WLAN secure system which can offer a safety secure communication and a user authentications by intensified the vulnerability of spoofing and DoS attacks. The suppose system offers a safe secure communication because it offers sending message of integrity service and also it prevents DoS attack at authentication initial phase.

Effects of Aqueous Extract Isolated from Platycodon grandiflorum Against t-Buty lhydroperoxide-induced Oxidative Stress in Rat Primary Hepatocytes (일차배양 간세포에서 t-Buty lhydroperoxide에 의해 유발된 산화적 스트레스에 대한 길경 열수 추출물의 보호효과)

  • 최철웅;이경진;정혜광
    • YAKHAK HOEJI
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    • v.46 no.6
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    • pp.466-471
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    • 2002
  • Oxidative stress is considered to be associated with many diseases, such as inflammatory and cardiovascular diseases, aging and cancer. An important etiological mechanism of these diseases may be a causal relationship between the presence of oxidants and the generation of lipid hydroperoxides derived from enzymatic reactions or xenobiotic metabolism. The hydroperoxides can be decomposed to alkoxy- (ROㆍ) and peroxy- (ROOㆍ) free radicals that can oxidize other cell components, resulting in changes in enzyme activity or the generation of mediators, which can cause further cell damage. The aim of this study was to evaluate the ability of aqueous extract from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil (CK), to affect cellular response in primary cultures of rat hepatocytes to t-butyl hydroperoxide (t-BHP) induced oxidative stress and hepatotoxicity. CK-treated cells showed an increased resistance to oxidative challenge, as revealed by a higher percent of survival capacity in respect to control cells. CK reduced t-BHP-enhanced lipid peroxidation measured as production of malondialdehyde and enhanced intracellular reduced glutathione depletion by t-BHP. Furthermore, CK protected from the t-BHP-induced intracellular generation of reactive oxygen species assessed by monitoring dichlorodihydrofluorescein fluorescence. It can be concluded that CK exerts an antioxidant action inside the cell, responsible for the observed modulation of the cellular response to oxidative challenge, and CK have a marked antioxidative and hepatoprotective potency.

Gene structure and expression characteristics of liver-expressed antimicrobial peptide-2 isoforms in mud loach (Misgurnus mizolepis, Cypriniformes)

  • Lee, Sang Yoon;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • v.20 no.12
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    • pp.31.1-31.11
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    • 2017
  • Background: Liver-expressed antimicrobial peptide-2 (LEAP-2) is an important component of innate immune system in teleosts. In order to understand isoform-specific involvement and regulation of LEAP-2 genes in mud loach (Misgurnus mizolepis, Cypriniformes), a commercially important food fish, this study was aimed to characterize gene structure and expression characteristics of two paralog LEAP-2 isoforms. Results: Mud loach LEAP-2 isoforms (LEAP-2A and LEAP-2B) showed conserved features in the core structure of mature peptides characterized by four Cys residues to form two disulfide bonds. The two paralog isoforms represented a tripartite genomic organization, known as a common structure of vertebrate LEAP-2 genes. Bioinformatic analysis predicted various transcription factor binding motifs in the 5'-flanking regions of mud loach LEAP-2 genes with regard to development and immune response. Mud loach LEAP-2A and LEAP-2B isoforms exhibited different tissue expression patterns and were developmentally regulated. Both isoforms are rapidly modulated toward upregulation during bacterial challenge in an isoform and/or tissue-dependent fashion. Conclusion: Both LEAP-2 isoforms play protective roles not only in embryonic and larval development but also in early immune response to bacterial invasion in mud loach. The regulation pattern of the two isoform genes under basal and stimulated conditions would be isoform-specific, suggestive of a certain degree of functional divergence between isoforms in innate immune system in this species.

Immunomodulatory effect of Tinospora cordifolia and Centella asiatica and its modulation on cyclophosphamide challenge

  • Siddiqui, NA;Ali, Mohd;Singh, Shobhna
    • Advances in Traditional Medicine
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    • v.8 no.4
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    • pp.380-385
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    • 2008
  • Ethanolic extracts of T. cordifolia and C. asiatica were evaluated for immunostimulatory effect in mice against sheep RBCs as antigen by three models viz. delayed type hypersensitivity reaction, ercent change in neutrophil count and haemagglutination titre. Immunostimulatory effect in the presence of immunosuppressant agent, cyclophosphamide (100 mg/kg, i.p.) was also investigated. T. cordifolia and C. asiatica significantly (p < 0.001, p < 0.05 respectively) enhanced foot pad thickness when measured after 24 hours of sheep RBC antigen challenge. Both the plant materials increased foot pad thickness even after being subjected to immunosuppressant exposure. T. cordifolia revealed enhanced neutrophil counts, while C. asiatica had no significant effect on neutrophil counts. T. cordifolia exhibited significantly (P < 0.01) elevated neutrophil levels even in the presence of cyclophosphamide administration. Both the plants exhibited humoral antibody response, as haemagglutination titre values were significantly high as compared to control. T. cordifolia and C. asiatica could combat immunosuppressant effect of cyclophosphamide (P < 0.01). This suggests that T. cordifolia and C. asiatica can be regarded as biological response modifiers and can be utilized for the development of immunostimulating agent among plant sources.

The design of User authentication system by using Public key cryptography system and one time password (공개키 암호화 시스템과 일회성 패스워드를 이용한 사용자 인증 시스템 설계)

  • 이상준;김영길
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.05a
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    • pp.498-501
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    • 2002
  • In the process of Log-In to the system, clear User authentication is the beginning of the information protection service. In the open communication system of today, it is true that a password as security instrument and the inner mechanism of the system and cryptography algorithm for the support of this are also poor. For this reason, this dissertation had a final aim to design the user authentication system, which offer the accuracy and safety. It used RSA and CBC mode of DES as cryptography algorithm and used the Challenge-Response scheme at a authentication protocol and designed the User authentication system to which user access using one time password, output of token to guarantee the safety of the authentication protocol. Alto by using the Public key cryptography algorithm, it could embody the more safe User authentication system.

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