Eliciting unnatural immune responses by activating cryptic epitopes in viral antigens

Lee, Young Jae,Yu, Ji Eun,Kim, Paul,Lee, Jeong-Yoon,Cheong, Yu Cheol,Lee, Yoon Jae,Chang, Jun,Seong, Baik Lin Federation of American Societies for Experimental 2018 The FASEB Journal Vol.32 No.9

<P>Antigenic variation in viral surface antigens is a strategy for escaping the host’s adaptive immunity, whereas regions with pivotal functions for infection are less subject to antigenic variability. We hypothesized that genetically invariable and immunologically dormant regions of a viral surface antigen could be exposed to the host immune system and activated by rendering them susceptible to antigen-processing machinery in professional antigen-presenting cells (APCs). Considering the frequent antigen drift and shift in influenza viruses, we identified and used structural modeling to evaluate the conserved regions on the influenza hemagglutinin (HA) surface as potential epitopes. Mutant viruses containing the cleavage motifs of cathepsin S within HA were generated. Immunization of mice showed that the mutant, but not the wild-type virus, elicited specific antibodies against the cryptic epitope. Those antibodies were purified, and specific binding to HA was confirmed. These results suggest that an unnatural immune response can be elicited through the processing of target antigens in APCs, followed by presentation <I>via</I> the major histocompatibility complex, if not subjected to regulatory pathways. By harnessing the antigen-processing machinery, our study shows a proof-of-principle for designer vaccines with increased efficacy and safety by either activating cryptic, or inactivating naturally occurring, epitopes of viral antigens.—Lee, Y. J., Yu, J. E., Kim, P., Lee, J.-Y., Cheong, Y. C., Lee, Y. J., Chang, J., Seong, B. L. Eliciting unnatural immune responses by activating cryptic epitopes in viral antigens.</P>

림프절 유래 fibroblastic reticular cell의 효율적 항원처리 관련성에 대한 연구

김민환(Min Hwan Kim),이종환(Jong-Hwan Lee) 한국생명과학회 2016 생명과학회지 Vol.26 No.9

항원은 병원체로부터 유래한 질병인자다. 생명체는 항원에 대항하는 방어계인 면역계를 가지고 있다. 항원은 식세포작용, 항체, 보체 활성화, NK세포 혹은 MHC 분자를 통한 세포독성 T세포와 같은 방법을 통해서 처리된다. 림프절은 스트로마세포와 3차원 네트워크를 통해서 구성되어 있다. Fibroblastic reticular cells (FRC)는 림프절 T zone에서 T세포와 상호작용한다. FRC는 세포외 기질 생산과 homing 케모카인을 생산하여 감염에 대비한다. 하지만, FRC가 항원처리과정에 관련되어있다는 보고는 없다. 본 연구는 FRC의 항원처리 관련성에 대한 연구이다. 이를 위해 FRC는 대식세포, T세포, LPS, 그리고 TNFα와 같은 다양한 감염상황에 노출시켜 연구를 진행하였다. FRC가 대식세포 및 T세포와 공배양 했을 때 FRC가 형태적 변화와 FRC간 빈 공간 형성이 관찰 되었다. MMP 활성은 Y27632와 T세포에 의해 조절 되었다. 더욱이, 염증물질인 TNFα를 FRC에 처리 후 마이크로어레이를 통한 결과에서 부착분자와 MHC I antigen transporter의 발현을 조절하는 것으로 나타났다. FRC 단일층에 LPS와 대식세포를 공배양 했을 때 NO 생성력이 크게 향상되었다. GFP antigen을 FRC와 대식세포 공배양군에 처리 했을 때 항원 흡수율이 증가되었다. 이러 결과는 FRC가 항원처리에 관여하고 있다는 것을 의미하며 이는 림프절이 항원처리과정에 연관되어 있다는 것을 제시한다. Antigen is substance causing disease derived from pathogen. Living organism has the immune system in terms of defense mechanism against antigen. Antigen is processed through several pathways such as phagocytosis, antibody action, complement activation, and cytotoxins by NK or cytotoxic T lymphocyte via MHC molecule. Lymph node (LN) is comprised of the complicated 3 dimensional network and several stromal cells. Fibroblastic reticular cells (FRC) are distributed in T zone for interaction with T cells. FRC produces the extra cellular matrix (ECM) into LN for ECM reorganization against pathogen infections and secretes homing chemokines. However, it has not so much been known about the involvement of the antigen process of FRC. The present report is for the function of FRC on antigen process. For this, FRC was positioned with several infected situations such as co-culture with macrophage, T cell, lipopolysaccharide (LPS) and TNFα stimulation. When co-culture between FRC with macrophage and T cells was performed, morphological change of FRC was observed and empty space between FRCs was made by morphological change. The matrix metallo-proteinase (MMP) activity was up-regulated by Y27632 and T cells onto FRC. Furthermore, inflammatory cytokine, TNFα regulated the expression of adhesion molecules and MHC I antigen transporter in FRC by gene chip assay. NO production was elevated by FRC monolayer co-cultured with macrophage stimulated by LPS. GFP antigen was up-taken by macrophage co-cultured with FRC. Collectively, it suggests that FRC assists of the facilitation of antigen process and LN stroma is implicated into antigen process pathway.

Cyclooxygenase Inhibitors, Aspirin and Ibuprofen, Inhibit MHC-restricted Antigen Presentation in Dendritic Cells

Kim, Hyun-Jin,Lee, Young-Hee,Im, Sun-A,Kim, Kyungjae,Lee, Chong-Kil The Korean Association of Immunobiologists 2010 Immune Network Vol.10 No.3

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to relieve pain, reduce fever and inhibit inflammation. NSAIDs function mainly through inhibition of cyclooxygenase (COX). Growing evidence suggests that NSAIDs also have immunomodulatory effects on T and B cells. Here we examined the effects of NSAIDs on the antigen presenting function of dendritic cells (DCs). Methods: DCs were cultured in the presence of aspirin or ibuprofen, and then allowed to phagocytose biodegradable microspheres containing ovalbumin (OVA). After washing and fixing, the efficacy of OVA peptide presentation by DCs was evaluated using OVA-specific CD8 and CD4 T cells. Results: Aspirin and ibuprofen at high concentrations inhibited both MHC class I and class II-restricted presentation of OVA in DCs. In addition, the DCs generated in the presence of low concentrations of the drugs exhibit a profoundly suppressed capability to present MHC-restricted antigens. Aspirin and ibuprofen did not inhibit the phagocytic activity of DCs, the expression level of total MHC molecules and co-stimulatory molecules on DCs. Ibuprofen rather increased the expression level of total MHC molecules and co-stimulatory molecules on DCs. Conclusion: These results demonstrate that aspirin and ibuprofen inhibit the intracellular processing event of the phagocytosed antigen, and further suggest that prolonged administration of NSAIDs in high doses may impair the capability of DCs to present antigens in asiociation with MHC molecules.

Cyclooxygenase Inhibitors, Aspirin and Ibuprofen, Inhibit MHC-restricted Antigen Presentation in Dendritic Cells

이종길,김경제,김현진,이영희,임선아 대한면역학회 2010 Immune Network Vol.10 No.3

Nonsteroidal anti-inflammatory drugs (NSAIDs)are widely used to relieve pain, reduce fever and inhibit inflammation. NSAIDs function mainly through inhibition of cyclooxygenase (COX). Growing evidence suggests that NSAIDs also have immunomodulatory effects on T and B cells. Here we examined the effects of NSAIDs on the antigen presenting function of dendritic cells (DCs). Methods:DCs were cultured in the presence of aspirin or ibuprofen,and then allowed to phagocytose biodegradable microspheres containing ovalbumin (OVA). After washing and fixing,the efficacy of OVA peptide presentation by DCs was evaluated using OVA-specific CD8 and CD4 T cells. Results:Aspirin and ibuprofen at high concentrations inhibited both MHC class I and class II-restricted presentation of OVA in DCs. In addition, the DCs generated in the presence of low concentrations of the drugs exhibit a profoundly suppressed capability to present MHC-restricted antigens. Aspirin and ibuprofen did not inhibit the phagocytic activity of DCs, the expression level of total MHC molecules and co-stimulatory molecules on DCs. Ibuprofen rather increased the expression level of total MHC molecules and co-stimulatory molecules on DCs. Conclusion: These results demonstrate that aspirin and ibuprofen inhibit the intracellular processing event of the phagocytosed antigen, and further suggest that prolonged administration of NSAIDs in high doses may impair the capability of DCs to present antigens in asiociation with MHC molecules.

Evidence for Direct Inhibition of MHC-Restricted Antigen Processing by Dexamethasone

임선아,Turmunkh Gerelchuluun,이종길 대한면역학회 2014 Immune Network Vol.14 No.6

Dexamethasone (Dex) was shown to inhibit the differentiation,maturation, and antigen-presenting function ofdendritic cells (DC) when added during DC generation ormaturation stages. Here, we examined the direct effects ofDex on MHC-restricted antigen processing. Macrophageswere incubated with microencapsulated ovalbumin (OVA) inthe presence of different concentrations of Dex for 2 h, andthe efficacy of OVA peptide presentation was evaluated usingOVA-specific CD8 and CD4 T cells. Dex inhibited bothclass I- and class II-restricted presentation of OVA to T cells;this inhibitory effect on antigen presentation was much morepotent in immature macrophages than in mature macrophages. The presentation of the exogenously added OVApeptide SIINFEKL was not blocked by Dex. In addition,short-term treatment of macrophages with Dex had no discernibleeffects on the phagocytic activity, total expressionlevels of MHC molecules or co-stimulatory molecules. Theseresults demonstrate that Dex inhibits intracellular processingevents of phagocytosed antigens in macrophages

Evidence for Direct Inhibition of MHC-Restricted Antigen Processing by Dexamethasone

Im, Sun-A,Gerelchuluun, Turmunkh,Lee, Chong-Kil The Korean Association of Immunobiologists 2014 Immune Network Vol.14 No.6

Dexamethasone (Dex) was shown to inhibit the differentiation, maturation, and antigen-presenting function of dendritic cells (DC) when added during DC generation or maturation stages. Here, we examined the direct effects of Dex on MHC-restricted antigen processing. Macrophages were incubated with microencapsulated ovalbumin (OVA) in the presence of different concentrations of Dex for 2 h, and the efficacy of OVA peptide presentation was evaluated using OVA-specific CD8 and CD4 T cells. Dex inhibited both class I- and class II-restricted presentation of OVA to T cells; this inhibitory effect on antigen presentation was much more potent in immature macrophages than in mature macrophages. The presentation of the exogenously added OVA peptide SIINFEKL was not blocked by Dex. In addition, short-term treatment of macrophages with Dex had no discernible effects on the phagocytic activity, total expression levels of MHC molecules or co-stimulatory molecules. These results demonstrate that Dex inhibits intracellular processing events of phagocytosed antigens in macrophages.

Sulforaphane Enhances MHC Class II-Restricted Presentation of Exogenous Antigens

( Chong Kil Lee ),( Yoon Hee Park ),( Nam Joo Ha ),( Kyung Jae Kim ),( Kyung Hae Cho ),( Seul Mee Shin ),( Ki Sung Jung ),( Young Wook Ko ) 한국응용약물학회 2011 Biomolecules & Therapeutics(구 응용약물학회지) Vol.19 No.1

Sulforaphane is an isothiocyanate found in cruciferous vegetables that has been reported to be an effective cancer preventive agent inducing growth arrest and/or cell death in cancer cells of various organs. This paper reports that sulforaphane exerts immunomodulatory activity on the MHC-restricted antigen presenting function. Sulforaphane efficiently increased the class II-restricted presentation of an exogenous antigen, ovalbumin (OVA), in both dendritic cells (DCs) and peritoneal macrophages in vitro. The class II-restricted OVA presentation-enhancing activity of sulforaphane was also confirmed using mice that had been injected with sulforaphane followed by soluble OVA. On the other hand, sulforaphane did not affect the class I-restricted presentation of exogenous OVA at concentrations that increase the class II-restricted antigen presentation. At a high concentration (20 uM), sulforaphane inhibited the class I-restricted presentation of exogenous OVA. Sulforaphane did not affect the phagocytic activity of the DCs, and the cell surface expression of total H-2Kb, B7-1, B7-2 and CD54 molecules, even though it increased the expression of I-Ab molecules to a barely discernable level. These results show that sulforaphane increases the class II-restricted antigen presenting function preferentially, and might provide a novel insight into the mechanisms of the anti-cancer effects of sulforaphane

A Preparative Purification Process for Recombinant Hepatitis B Core Antigen Using Online Capture by Expanded Bed Adsorption Followed by Size-Exclusion Chromatography

Chin Woi Ho,Wen Siang Tan,Fui Chin Chong,Tau Chuan Ling,Beng Ti Tey 한국미생물 · 생명공학회 2009 Journal of microbiology and biotechnology Vol.19 No.4

T CELL EPITOPE RECOGNITION INVOLVED IN THE LOW-RESPONSIVENESS TO A REGION OF HEN EGG LYSOZYME (46-61) IN C57BL/6 MICE

JANG, YONG-SUK,MIKSZTA, JOHN A.,KIM, BYUNG S. 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.17 No.-

The predominant T cell epitope of hen egg lysozyme (HEL) in high-responder C3H mice has been previously identified as the HEL 46-61 region. In contrast, this region is poorly recognized by T cell from low-responder C57BL/6 mice upon immunization with HEL. In previous studies, we have demonstrated that several C57BL/6 derived T cell hybridomas reactive to this epitope and other HEL epitopes preferentially recognize phosphorylcholine (PC)-conjugated HEL over unconjugated HEL. To understand the mechanisms involved in this difference of T cell recognition, we have further analysed the reactivity of T cells and T cell hybridomas from low-responder C57BL/6 mice. T cells from HEL-immunized mice were preferentially reactive to HEL 47-60. These results suggest a potential deficiency in generating an appropriate T cell epitope from the 46-61 region of native HEL in low-responder C57BL/6 mice. The minimal T cell epitope of this region was defined as HEL 51-60 using the PCH4.1 T hybridoma clone. This minimal epitope represents a single amino acid shift from the minimal epitope of HEL high-responder C3H mice (HEL 52-61). Various peptides representing this region were synthesized with single alanine substitutions at each position. The residues at positions 51, 52, 53 and 57 of HEL 51-61 peptides with various substitutions at position 61 strongly suggest that primarily the size of the C-terminal residue interferes with binding to the Ia molecules of low-responder mice. In addition, substitutions of the TCR contacting residues at positions 55 and 56 with similar residues (isoleucine→leucine or leucine→isoleucine) significantly increased the T cell reactivity, suggesting a low reactivity with the native residues. Therefore, the requirement of many residues in the T cell epitope for interaction with Ia, the necessity for additional Ag processing to facilitate Ia binding, and the low affinity of the TCR contacting residues may together render C57BL/6 mice unresponsive to the HEL 46-61 region.