Immune Control Mechanisms Research Articles

Protein Interactions Network of Porcine Circovirus Type 2 Capsid With Host Proteins.

Virus-host interaction is a tug of war between pathogenesis and immunity, followed by either activating the host immune defense system to eliminate virus or manipulating host immune control mechanisms to survive and facilitate virus propagation. Comprehensive knowledge of interactions between host and viral proteins might provide hints for developing novel antiviral strategies. To gain a more detailed knowledge of the interactions with porcine circovirus type 2 capsid protein, we employed a coimmunoprecipitation combined with liquid chromatography mass spectrometry (LC-MS) approach and 222 putative PCV2 Cap-interacting host proteins were identified in the infected porcine kidney (PK-15) cells. Further, a protein-protein interactions (PPIs) network was plotted, and the PCV2 Cap-interacting host proteins were potentially involved in protein binding, DNA transcription, metabolism and innate immune response based on the gene ontology annotation and Kyoto Encyclopedia of Genes and Genomes database enrichment. Verification in vitro assay demonstrated that eight cellular proteins, namely heterogeneous nuclear ribonucleoprotein C, nucleophosmin-1, DEAD-box RNA helicase 21, importin β3, eukaryotic translation initiation factor 4A2, snail family transcriptional repressor 2, MX dynamin like GTPase 2, and intermediate chain 1 interacted with PCV2 Cap. Thus, this work effectively provides useful protein-related information to facilitate further investigation of the underlying mechanism of PCV2 infection and pathogenesis.

Structural and functional divergence of duplicated mosquito Toll and Spz compared to Drosophila

Abstract Mosquitoes are vectors of many infectious diseases that constitute a risk to human health around the globe. Arthropod-borne viruses (arboviruses) such as Dengue and Zika viruses, are mainly transmitted by Aedes mosquito species, while plasmodium is spread by members of the Anopheles genus. The vectorial capacity of mosquito is based on a complex balance between the mosquito’s immune control and evasion mechanisms by the pathogen. The Toll signalling pathway is a key component of insect innate immunity that underwent duplication in mosquitoes compared to Drosophila melanogaster (Dm). Here we produced duplicated Spz isoforms and ectodomains of Toll1A and Toll5A in order to study binding specificity and signalling in Aedes aegypti (Aa). Surprisingly, Toll1A, the closest structural homolog to DmToll, did not bind to DmSpz, AaSpz1B or AaSpz1C, while Toll5A specifically bound to Spz1C. In Aag2 cells, however, DmSpz triggered gambicin production upon proteolytic processing, in contrast to mosquito Spz isoforms, which lead to a distinct set of antimicrobial peptides. Computational pairing of Toll and Spz failed to predict isoform and species-specificity, probably due to conformational changes upon ligand binding as observed by SAXS analysis of Toll5A-Spz1C complex. This study sheds light on the molecular basis of Toll and Spz neofunctionalization in the mosquito.

Abstract IA19: Lymphatic vessels: Barriers to adaptive immunity in melanoma

Abstract Mechanisms of immune suppression in peripheral tissues counteract protective immunity to prevent immunopathology and are co-opted by tumors for immune escape. Nonhematopoietic cells, as the resident tissue scaffold, play critical roles in regulating the infiltration, retention, function, and exit of tissue- and tumor-infiltrating leukocytes. While lymphatic vessels facilitate T-cell priming through dendritic cell and antigen delivery to lymph nodes, they also facilitate regional metastasis and exert multiple immune-suppressive mechanisms that maintain peripheral tolerance in steady state lymph nodes. We hypothesized that in tumors peripheral lymphatic vessels exhibit context-dependent function that limits local effector CD8+ T-cell accumulation in melanoma. Our work demonstrates that lymphatic vessels both maintain homeostatic mechanisms of peripheral tolerance in poorly inflamed tumors to limit immune surveillance and activate mechanisms of adaptive immune resistance in the context of potent cytotoxic T-cell activity. Consequently, we present tumor-associated lymphatic vessels as a new, anatomic immune checkpoint in melanoma. Our work suggests that understanding context-dependent lymphatic vessel function will continue to reveal novel mechanisms of immune control and metastasis that may be targeted for therapeutic response. Citation Format: Amanda W. Lund. Lymphatic vessels: Barriers to adaptive immunity in melanoma [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr IA19.

Abstract A78: IFNg-activated lymphatic vessels express PD-L1 and suppress effector T-cell function in melanoma

Abstract Peripheral tissues adopt mechanisms of immune suppression that counteract protective immunity to prevent immunopathology and are co-opted by tumors for immune escape. In tumors, cytotoxic, antigen-specific T cells produce IFNg and activate multiple mechanisms of adaptive immune resistance, including upregulation of the T-cell inhibitory molecule programed death ligand 1 (PD-L1). Tumor cell PD-L1 expression does not predict response to anti-PD-L1 immunotherapy, indicating, however, that other sources of PD-L1 in tumor microenvironments may contribute to PD-L1-dependent immune suppression. Lymphatic vessels facilitate antigen and dendritic cell transport to draining lymph nodes and are required for antitumor immunity. Interestingly, lymphatic endothelial cells in lymph nodes are tolerogenic at steady-state and constitutively express PD-L1 to delete self-reactive CD8+ T cells. However, whether lymphatic endothelial cells in tumor microenvironments are also directly immunosuppressive remains unclear. Here we test the hypothesis that peripheral, tumor-associated lymphatic vessels acquire immunosuppressive mechanisms, e.g., PD-L1 expression, that limit effector CD8+ T-cell accumulation and function in melanoma. We demonstrate that host nonhematopoietic, nontumor, PD-L1 limits CD8+ T-cell accumulation in murine melanoma. Further, we show that tumor-associated lymphatic endothelial cells upregulate PD-L1 in response to IFNg produced by tumor-infiltrating, antigen-specific CD8+ T cells. As such, loss of IFNgR by lymphatic endothelial cells improves CD8+ T-cell accumulation in murine melanomas, thereby enhancing tumor control and improved overall survival. Importantly, this robust lymphatic vessel-dependent tumor control was revealed in the context of murine melanomas with significant UVB-induced somatic mutation burden, consistent with a cytotoxic T cell-mediated negative feedback mechanism. Consequently, we present IFNg-mediated activation of tumor-associated lymphatic vessels as a new component of adaptive immune resistance, suggesting that context-dependent lymphatic vessel function may provide novel, targetable mechanisms of immune control in melanoma. Citation Format: Ryan S. Lane, Alec P. Breazeale, Amanda W. Lund. IFNg-activated lymphatic vessels express PD-L1 and suppress effector T-cell function in melanoma [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr A78.

Promoting Roles of Embryonic Signals in Embryo Implantation and Placentation in Cooperation with Endocrine and Immune Systems.

Embryo implantation in the uterus is an essential process for successful pregnancy in mammals. In general, the endocrine system induces sufficient embryo receptivity in the endometrium, where adhesion-promoting molecules increase and adhesion-inhibitory molecules decrease. Although the precise mechanisms remain unknown, it is widely accepted that maternal–embryo communications, including embryonic signals, improve the receptive ability of the sex steroid hormone-primed endometrium. The embryo may utilize repulsive forces produced by an Eph–ephrin system for its timely attachment to and subsequent invasion through the endometrial epithelial layer. Importantly, the embryonic signals are considered to act on maternal immune cells to induce immune tolerance. They also elicit local inflammation that promotes endometrial differentiation and maternal tissue remodeling during embryo implantation and placentation. Additional clarification of the immune control mechanisms by embryonic signals, such as human chorionic gonadotropin, pre-implantation factor, zona pellucida degradation products, and laeverin, will aid in the further development of immunotherapy to minimize implantation failure in the future.

Protective HLA alleles are associated with reduced LPS levels in acute HIV infection with implications for immune activation and pathogenesis.

Despite extensive research on the mechanisms of HLA-mediated immune control of HIV-1 pathogenesis, it is clear that much remains to be discovered, as exemplified by protective HLA alleles like HLA-B*81 which are associated with profound protection from CD4+ T cell decline without robust control of early plasma viremia. Here, we report on additional HLA class I (B*1401, B*57, B*5801, as well as B*81), and HLA class II (DQB1*02 and DRB1*15) alleles that display discordant virological and immunological phenotypes in a Zambian early infection cohort. HLA class I alleles of this nature were also associated with enhanced immune responses to conserved epitopes in Gag. Furthermore, these HLA class I alleles were associated with reduced levels of lipopolysaccharide (LPS) in the plasma during acute infection. Elevated LPS levels measured early in infection predicted accelerated CD4+ T cell decline, as well as immune activation and exhaustion. Taken together, these data suggest novel mechanisms for HLA-mediated immune control of HIV-1 pathogenesis that do not necessarily involve significant control of early viremia and point to microbial translocation as a direct driver of HIV-1 pathogenesis rather than simply a consequence.

Myeloid-Derived Suppressor Cells: Not Only in Tumor Immunity.

Since the realization that immature myeloid cells are powerful modulators of the immune response, many studies on “myeloid-derived suppressor cells” (MDSCs) have documented their ability to promote tumor progression in melanoma and other cancers. Whether MDSCs are induced solely pathologically in tumorigenesis, or whether they also represent physiological immune control mechanisms, is not well-understood, but is particularly important in the light of ongoing attempts to block their activities in order to enhance anti-tumor immunity. Here, we briefly review studies which explore (1) how best to identify MDSCs in the context of cancer and how this compares to other conditions in humans; (2) what the suppressive mechanisms of MDSCs are and how to target them pharmacologically; (3) whether levels of MDSCs with various phenotypes are informative for clinical outcome not only in cancer but also other diseases, and (4) whether MDSCs are only found under pathological conditions or whether they also represent a physiological regulatory mechanism for the feedback control of immunity. Studies unequivocally document that MDSCs strongly influence cancer outcomes, but are less informative regarding their relevance to infection, autoimmunity, transplantation and aging, especially in humans. So far, the results of clinical interventions to reverse their negative effects in cancer have been disappointing; thus, developing differential approaches to modulate MSDCs in cancer and other diseases without unduly comprising any normal physiological function requires further exploration.

The E3 Ligase TRAF6 directs FOXP3 localization and facilitates Treg function through K63‐type ubiquitination

For the immune system to function properly, the activation of leukocytes must be tightly regulated. Failures of immune control mechanisms underlie the aberrant targeting of self‐antigens (i.e. autoimmunity) and the collateral damage of healthy tissues during excessive responses to infectious threats or the unnecessary immune mobilization against innocuous commensal microbes. Foxp3‐expressing CD4+ Regulatory T cells (Tregs) are a major cellular force working to prevent these pathologies of immune dysregulation. These cells characteristically exhibit multiple suppressive function that is absolutely required for the maintenance of immune homeostasis. However, these cells can hamper desirable anti‐tumor immune responses in cancer patients. Accordingly, a relative abundance of Tregs in the tumor microenvironment (TME) is a negative prognostic factor in many cancers. Treg‐depleting or antagonizing strategies show promise as potential interventions capable of unleashing anti‐tumor immunity from suppression. The characteristic gene expression and suppressive function of Tregs depend considerably on the stable expression and activity of the transcription factor FOXP3. While transcriptional regulation of the Foxp3gene has been studied in depth, both the expression and function of this factor are also modulated at the protein level. However, the molecular players involved in posttranslational FOXP3 regulation are just beginning to be elucidated. We have found that in the absence of the E3 ligase TRAF6 Tregs were dysfunctional in vivo. In these studies, mice with Treg‐restricted deletion of TRAF6 were highly resistant to implanted tumors and displayed enhanced anti‐tumor immunity. We further determined that FOXP3 undergoes lysine‐63 linked (K63) ubiquitination at lysine 262, and this posttranslational modification was mediated by TRAF6. When deprived of TRAF6 activity or rendered insensitive to K63 ubiquitination, FOXP3 displayed aberrant, perinuclear accumulation and disrupted regulatory function. Thus, K63 ubiquitination by TRAF6 ensures proper localization of FOXP3 and facilitates the transcription factor's gene‐regulating activity in Tregs. These results implicate TRAF6 as a key, hitherto unappreciated posttranslational facilitator of FOXP3 stabilization and Treg suppressive function that may be targeted by novel tolerance‐breaking immunotherapies to improve anti‐tumor immunity and combat disease progression in cancer patients.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Mechanisms of Immune Control of Mucosal HSV Infection: A Guide to Rational Vaccine Design.

Herpes Simplex Virus (HSV) is a highly prevalent sexually transmitted infection that aside from causing cold sores and genital lesions, causes complications in the immunocompromised and has facilitated a large proportion of HIV acquisition globally. Despite decades of research, there is no prophylactic HSV vaccine ready for use in humans, leaving many questioning whether a prophylactic vaccine is an achievable goal. A previous HSV vaccine trial did have partial success in decreasing acquisition of HSV2–promising evidence that vaccines can prevent acquisition. However, there is still an incomplete understanding of the immune response pathways elicited by HSV after initial mucosal infection and how best to replicate these responses with a vaccine, such that acquisition and colonization of the dorsal root ganglia could be prevented. Another factor to consider in the rational design of an HSV vaccine is adjuvant choice. Understanding the immune responses elicited by different adjuvants and whether lasting humoral and cell-mediated responses are induced is important, especially when studies of past trial vaccines found that a sufficiently protective cell-mediated response was lacking. In this review, we discuss what is known of the immune control involved in initial herpes lesions and reactivation, including the importance of CD4 and CD8 T cells, and the interplay between innate and adaptive immunity in response to primary infection, specifically focusing on the viral relay involved. Additionally, a summary of previous and current vaccine trials, including the components used, immune responses elicited and the feasibility of prophylactic vaccines looking forward, will also be discussed.

Interferon lambda protects the female reproductive tract against Zika virus infection

Although Zika virus (ZIKV) can be transmitted sexually and cause congenital birth defects, immune control mechanisms in the female reproductive tract (FRT) are not well characterized. Here we show that treatment of primary human vaginal and cervical epithelial cells with interferon (IFN)-α/β or IFN-λ induces host defense transcriptional signatures and inhibits ZIKV infection. We also assess the effects of IFNs on intravaginal infection of the FRT using ovariectomized mice treated with reproductive hormones. We find that mice receiving estradiol are protected against intravaginal ZIKV infection, independently of IFN-α/β or IFN-λ signaling. In contrast, mice lacking IFN-λ signaling sustain greater FRT infection when progesterone is administered. Exogenous IFN-λ treatment confers an antiviral effect when mice receive both estradiol and progesterone, but not progesterone alone. Our results identify a hormonal stage-dependent role for IFN-λ in controlling ZIKV infection in the FRT and suggest a path for minimizing sexual transmission of ZIKV in women.

Mathematical modeling of within-host Zika virus dynamics.

Recent Zika virus outbreaks have been associated with severe outcomes, especially during pregnancy. A great deal of effort has been put toward understanding this virus, particularly the immune mechanisms responsible for rapid viral control in the majority of infections. Identifying and understanding the key mechanisms of immune control will provide the foundation for the development of effective vaccines and antiviral therapy. Here, we outline a mathematical modeling approach for analyzing the within-host dynamics of Zika virus, and we describe how these models can be used to understand key aspects of the viral life cycle and to predict antiviral efficacy.

A Novel Marsupial Hepatitis A Virus Corroborates Complex Evolutionary Patterns Shaping the Genus Hepatovirus.

ABSTRACTThe discovery of highly diverse nonprimate hepatoviruses illuminated the evolutionary origins of hepatitis A virus (HAV) ancestors in mammals other than primates. Marsupials are ancient mammals that diverged from other Eutheria during the Jurassic. Viruses from marsupials may thus provide important insight into virus evolution. To investigate Hepatovirus macroevolutionary patterns, we sampled 112 opossums in northeastern Brazil. A novel marsupial HAV (MHAV) in the Brazilian common opossum (Didelphis aurita) was detected by nested reverse transcription-PCR (RT-PCR). MHAV concentration in the liver was high, at 2.5 × 109 RNA copies/g, and at least 300-fold higher than those in other solid organs, suggesting hepatotropism. Hepatovirus seroprevalence in D. aurita was 26.6% as determined using an enzyme-linked immunosorbent assay (ELISA). Endpoint titers in confirmatory immunofluorescence assays were high, and marsupial antibodies colocalized with anti-HAV control sera, suggesting specificity of serological detection and considerable antigenic relatedness between HAV and MHAV. MHAV showed all genomic hallmarks defining hepatoviruses, including late-domain motifs likely involved in quasi-envelope acquisition, a predicted C-terminal pX extension of VP1, strong avoidance of CpG dinucleotides, and a type 3 internal ribosomal entry site. Translated polyprotein gene sequence distances of at least 23.7% from other hepatoviruses suggested that MHAV represents a novel Hepatovirus species. Conserved predicted cleavage sites suggested similarities in polyprotein processing between HAV and MHAV. MHAV was nested within rodent hepatoviruses in phylogenetic reconstructions, suggesting an ancestral hepatovirus host switch from rodents into marsupials. Cophylogenetic reconciliations of host and hepatovirus phylogenies confirmed that host-independent macroevolutionary patterns shaped the phylogenetic relationships of extant hepatoviruses. Although marsupials are synanthropic and consumed as wild game in Brazil, HAV community protective immunity may limit the zoonotic potential of MHAV.IMPORTANCE Hepatitis A virus (HAV) is a ubiquitous cause of acute hepatitis in humans. Recent findings revealed the evolutionary origins of HAV and the genus Hepatovirus defined by HAV in mammals other than primates in general and in small mammals in particular. The factors shaping the genealogy of extant hepatoviruses are unclear. We sampled marsupials, one of the most ancient mammalian lineages, and identified a novel marsupial HAV (MHAV). The novel MHAV shared specific features with HAV, including hepatotropism, antigenicity, genome structure, and a common ancestor in phylogenetic reconstructions. Coevolutionary analyses revealed that host-independent evolutionary patterns contributed most to the current phylogeny of hepatoviruses and that MHAV was the most drastic example of a cross-order host switch of any hepatovirus observed so far. The divergence of marsupials from other mammals offers unique opportunities to investigate HAV species barriers and whether mechanisms of HAV immune control are evolutionarily conserved.

Interleukin-1β Signaling in Dendritic Cells Induces Antiviral Interferon Responses.

ABSTRACTInduction of interferon beta (IFN-β), IFN-stimulated genes (ISGs), and inflammatory responses is critical for control of viral infection. We recently identified an essential linkage of stimulation of the inflammatory cytokine interleukin-1β (IL-1β) and induction of ISGs that function as host restriction pathways against the emerging flavivirus West Nile virus (WNV) in vivo. Here we utilized ex vivo global transcriptome analysis of primary dendritic cells, known targets of WNV replication, to define gene signatures required for this IL-1β-driven antiviral response. Dendritic cells that were deficient in IL-1 receptor signaling showed dysregulation of cell-intrinsic defense genes and loss of viral control during WNV infection. Surprisingly, we found that in wild-type cells, IL-1β treatment, in the absence of infection, drove the transcription of IFN-β and ISGs at late times following treatment. Expression of these antiviral innate immune genes was dependent on the transcription factor IFN regulatory factor 3 (IRF3) and appears to reflect a general shift in IL-1β signaling from an early inflammatory response to a late IFN-mediated response. These data demonstrate that inflammatory and antiviral signals integrate to control viral infection in myeloid cells through a process of IL-1β-to-IRF3 signaling crosstalk. Strategies to exploit these cytokines in the activation of host defense programs should be investigated as novel therapeutic approaches against individual pathogens.

Immuno-oncology from the perspective of somatic evolution.

The past years have witnessed significant success for cancer immunotherapies that activate a patient's immune system against their cancer cells. At the same time our understanding of the genetic changes driving tumor evolution have progressed dramatically. The study of cancer genomes has shown that tumors are best understood as cell populations governed by the rules of evolution, leading to the emergence and spread of cell lineages with pathogenic mutations. Moreover, somatic evolution can explain the acquisition of mutations conferring drug resistance in the ever-lasting battle for reaching even fitter cell states. Here, we review the current state of the art of somatic cancer evolution and mechanisms of immune control and escape. We also revisit the principles of immunotherapy from the perspective of somatic evolution and discuss the basic rules of resistance to immunotherapies as dictated by evolution.

Effect of Immune Status on Outcomes and Response to Radiation Among Merkel Cell Carcinoma Patients

Merkel cell carcinoma (MCC) is a rare, radiosensitive neuroendocrine skin cancer seen in elderly and immunosuppressed (IS) patients. Conventionally fractionated radiation (RT) is frequently incorporated as treatment. We hypothesized that as RT efficacy is promoted by an intact immune system, RT in IS MCC patients is less effective (increased local/regional recurrence [LRR]), which translates to inferior relapse-free survival (RFS) compared with immune-competent (IC) patients. We retrospectively reviewed a registry that enrolled MCC patients diagnosed between 1980 and 2016, which yielded 827 stage I-III MCC patients treated with curative intent therapy. Clinical and treatment characteristics were compared among IC and IS MCC patients. Endpoints included MCC-specific RFS, overall survival (OS), and patterns of recurrence. OS and RFS were estimated by the Kaplan-Meier method and cumulative incidence function, respectively. Eleven percent (n=89) of the cohort were IS, which comprised HIV/AIDS (8%), CLL (32%), solid organ transplant (22%), autoimmune disease (20%), and other hematologic malignancies (18%). While age (median 68 yrs for both) and stage were similar between IS and IC groups, more IS patients were male and received chemotherapy (CT) and/or RT (Table). RT dose was similar between IS and IC groups (median, 50.4 vs 50.3 Gy), although more IS patients received RT to the primary site (97% vs 81%) and/or regional nodes (70% vs 66%). With a median follow-up of 56.3 months among living patients, RFS and OS were inferior among IS patients (median RFS 10.2 vs 39.8 mo; median OS 25.1 vs 107.1 mo; p<.0001 for both). Based on analysis of patterns of first recurrence, IS patients experienced increased LRR compared to IC patients (1-yr: 37% vs 20%; p=.001) with a trend for distant disease (1-yr: 18% vs 10%; p=.28). The association between RT and RFS differed between IC and IS patients (interaction p-value =.02). While RT was associated with significantly improved RFS among IC patients (HR 0.68; 95% CI 0.53-0.86), RT either had no effect or decreased RFS compared to IS patients that did not receive RT (HR 1.70; 95% CI 0.81-3.58).Abstract 2857; TableIC (n=738)IS (n=89)Male sex457 (62%)64 (72%)Pathologic stage IA/IIA237 (32%)29 (33%) IB/IIB/IIC170 (23%)23 (26%) IIIA129 (17%)19 (21%) IIIB202 (27%)18 (20%)CT: Yes82 (12%)16 (18%)RT: Yes546 (78%)76 (86%) Open table in a new tab Despite more aggressive treatment of IS MCC patients, outcomes were inferior to IC patients. Notably, IS patients experienced increased LRR suggesting the importance of immune mechanisms in RT tumor control. While these findings require confirmation in other cohorts, they suggest that MCC in IS patients may be more radioresistant to conventional RT. Alternate strategies should be explored, including RT intensification (RBE, dose, acceleration) and/or early integration of systemic/targeted therapy.

아토피 동물모델에서 고삼백선피복합방(GBBB)의 아토피 억제효과

아토피 피부염(AD)에 대한 고삼백선피복합방(GBBB)의 치료적 가능성을 증명하기 위해 동물모델에서 다양한 면역 관련 인자들과 조직학적 변화에 대한 GBBB의 영향을 평가하였다. 실험 결과는 다음과 같다. GBBB도포군은 관능평가 결과에서 AD의 개선징후를 나타냈다. GBBB 도포군은 대조군에 비해 혈액 내 백혈구, 호중구, 림프구, 단핵구 면역세포 비율이 54%, 63%, 57%, 86%로 감소되었다. 또한 GBBB도포군은 대조군에 비해 혈청 내 IL-4, IL-5, IL-13, Histamine 및 IgE 생성량이 각각 40%, 80%, 62%, 61%, 57%로 유의성 있게 감소되었다. H&E 염색에서 GBBB 도포군은 대조군에 비하여 비만세포가 피부로 침윤되는 것이 억제되었으며 피부두께 역시 상대적으로 감소되었다. 이 결과를 바탕으로 GBBB는 피부에 직접 도포하는 AD 치료제로서 가능성이 있음이 확인하였다. 후속연구에서는 분자생물학적 연구를 통해 GBBB의 면역조절 기전을 구체적으로 밝히고자 한다. In order to clarify the Gosambaeksunpibokhap-bang(GBBB)'s therapeutic possibility on atopic dermatitis (AD), influences of GBBB on the changes of various immune-related factors and histological changes in NC/Nga mice were evaluated. Experimental results are as follows. Sign of recovery from AD was observed in GBBB treated group with naked eye test. The ratio of white blood cells, neutrophil, lymphocytes, monocyte in blood were decreased to 54%, 63%, 57% and 86% respectively in the GBBB group. IL-4, IL-5, IL-13, Histamine and IgE were significantly decreased to 40%, 80%, 62%, 61% and 57% respectively in the GBBB group. H&E staining showed thickness of epidermis and dermis were decreased by GBBB and inhibited the infiltration of lymphocytes. On the basis of these results, GBBB was confirmed that the possibility as an AD treatment applied externally to the skin. In the further study, immune control mechanism of GBBB will be demonstrated through the additional molecular biological research.

The Importance of Understanding MHC-I Diversity in Nonhuman Primate Models of Human Infectious Diseases.

Decades of research, including the 1996 Nobel Prize in Medicine, confirm the evolutionary and immunological importance of CD8 T lymphocytes (TCD8+) that target peptides bound by the highly variable major histocompatibility complex class I (MHC-I) proteins. However, their perceived importance has varied dramatically over the past decade. Regardless, there remains myriad reasons to consider the diversity of MHC-I alleles and the TCD8+ that target them as enormously important in infectious disease research. Thus, understanding these molecules in the best animal models of human disease could be a necessity for optimizing the translational potential of these models. Knowledge of macaque MHC has substantially improved their utility for modeling HIV and could aid in modeling other viruses as well, both in the context of distribution of alleles across treatment groups in vaccine trials and in deciphering mechanisms of immune control of pathogens for which specific MHC alleles demonstrate differential impacts on disease.

Abstract 1320: PD-L1: the hand brake of immune responses in cervical intraepithelial neoplasia and cancer

Abstract Background: Prospective cohort studies have reported spontaneous regression rates of high-grade cervical intraepithelial Neoplasia (CIN2/3) close to 35%, over a period of 4-6 months. These regressions are presumably immunologically mediated. It is now well recognized that PD-L1 is an immune checkpoint used by neoplastic cells to evade the immune system, particularly T cells that are specific for tumor antigens. PD-L1 and several other immune checkpoints consist of inhibitory pathways that tightly regulate the immune system to control the duration and amplitude of immune responses in peripheral tissues in order to minimize collateral tissue damage. Design: Immunohistochemistry with anti-TBX21 and anti-PD-L1 antibodies was performed in formalin-fixed paraffin-embedded tissue sections from a tissue microarray consisting of invasive cervical carcinomas (ICCs) (n = 22), CIN2/3 (n = 4) and benign cervical tissues (n = 4). Expression of TBX21 and PD-L1 was reviewed and scored by a trained pathologist blinded to the clinical outcome of each case. Statistical correlations between these markers’ score and available demographic and clinicopathologic data from each case were performed, as well as disease-free survival curves. Moreover, PD-L1 staining was performed in three patients with CIN2/3 that received peripheral (IM) therapeutic HPV vaccination. PD-L1 expression differences in pre and post-vaccination tissues were compared. Results: Increased expression of TBX21+ T-cells and PD-L1 was observed from benign to CIN2/3 to ICCs. Association analysis (fisher exact test) showed a significant correlation between increased intraepithelial and stromal infiltration of TBX21+ T-cells (score 2,3) and higher PD-L1 membrane expression (p = 0.04 and p = 0.005, respectively). No significant associations were found between PD-L1 expression and demographic and clinicopathologic information, likely due to small number of samples. In our vaccine cohort, we observed a stronger membrane PD-L1 expression in the epithelium and stroma of the post-vaccination tissue compared to the pre-vaccination biopsy. Conclusion: Increased membrane expression of PD-L1 is tightly correlated with an increased epithelial and stromal infiltration of TBX21+ T cells in CIN2/3 and ICCs. This correlation was also observed in our vaccination cohort when compared to our previous published findings of immune activation after HPV therapeutic vaccination. This association could represent an immune response control mechanism induced presumably by interferons released by TBX21+ T cells. We are currently evaluating the expression of PD-L1 and B7-H4, a recently discovered inhibitory ligand, in a larger cohort of benign, CIN2/3 and ICCs. Finally, we will further explore, quantitate and compare the expression changes of these immune checkpoints in the remaining CIN2/3 cases of our vaccination cohort (n = 12) in pre and post-vaccination tissues. Citation Format: Leonel F. Maldonado Gonzalez, Christopher VandenBussche, Richard Roden, T.C. Wu, Benjamin Tycko, Cornelia L. Trimble. PD-L1: the hand brake of immune responses in cervical intraepithelial neoplasia and cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1320. doi:10.1158/1538-7445.AM2015-1320

Rejection triggers liver transplant tolerance: Involvement of mesenchyme-mediated immune control mechanisms in mice.

Liver tolerance was initially recognized by the spontaneous acceptance of liver allografts in many species. The underlying mechanisms are not completely understood. However, liver transplant (LT) tolerance absolutely requires interferon (IFN)-γ, a rejection-associated inflammatory cytokine. In this study, we investigated the rejection of liver allografts deficient in the IFN-γ receptor and reveal that the liver graft is equipped with machineries capable of counterattacking the host immune response through a mesenchyme-mediated immune control (MMIC) mechanism. MMIC is triggered by T effector (Tef) cell-derived IFN-γ that drives expression of B7-H1 on graft mesenchymal cells leading to Tef cell apoptosis. We describe the negative feedback loop between graft mesenchymal and Tef cells that ultimately results in LT tolerance. Comparable elevations of T-regulatory cells and myeloid-derived suppressor cells were observed in both rejection and tolerance groups and were not dependent on IFN-γ stimulation, suggesting a critical role of Tef cell elimination in tolerance induction. We identify potent MMIC activity in hepatic stellate cells and liver sinusoidal endothelial cells. MMIC is unlikely exclusive to the liver, given that spontaneous acceptance of kidney allografts has been reported, although less commonly, probably reflecting variance in MMIC activity. MMIC may represent an important homeostatic mechanism that supports peripheral tolerance and could be a target for the prevention and treatment of transplant rejection. This study highlights that the graft is an active participant in the equipoise between tolerance and rejection and warrants more attention in the search for tolerance biomarkers.

Multi-step regulation of innate immune signaling by Kaposi's sarcoma-associated herpesvirus

The innate immune system provides an immediate and relatively non-specific response to infection with the aim of eliminating the pathogen before an infection can be fully established. Activation of innate immune response is achieved by production of pro-inflammatory cytokines and type I interferon (IFN). The IFN response in particular is one of the primary defenses utilized by the host innate immune system to control pathogen infection, like virus infection. Hence, viruses have learned to manipulate host immune control mechanisms to facilitate their propagation. Due to this, much work has been dedicated to the elucidation of the Kaposi's sarcoma-associated herpesvirus (KSHV)-mediated immune evasion tactics that antagonize a host's immune system. This review presents our current knowledge of the immune evasion strategies employed by KSHV at distinct stages of its life cycle to control a host's immune system with a focus on interferon signaling.