Submitted by MARCOS AURELIO RIBEIRO DA SILVA (marcosars@ufba.br) on 2016-01-15T17:25:17Z No. of bitstreams: 1 Dissertação de Mestrado - Denisar.pdf: 3263987 bytes, checksum: 526d1efae345d51d6e41a539652a0a6f (MD5) / Approved for entry into archive by MARCOS AURELIO RIBEIRO DA SILVA (marcosars@ufba.br) on 2016-01-15T17:29:22Z (GMT) No. of bitstreams: 1 Dissertação de Mestrado - Denisar.pdf: 3263987 bytes, checksum: 526d1efae345d51d6e41a539652a0a6f (MD5) / Made available in DSpace on 2016-01-15T17:29:22Z (GMT). No. of bitstreams: 1 Dissertação de Mestrado - Denisar.pdf: 3263987 bytes, checksum: 526d1efae345d51d6e41a539652a0a6f (MD5) / CAPES / PALMITO, Denisar dos Santos. Camundongos C57Bl/6 e A/j apresentam resposta inflamatória diferenciada após a imunização com Staphylococcus aureus e desafio em modelo de bolsão de ar. Dissertação (Mestrado) – Instituto Multidisciplinar de Saúde, Universidade Federal da Bahia, Vitória da Conquista, 2015. Introdução/Objetivo: Staphylococcus aureus é o principal agente etiológico de infecções bacterianas em humanos, sendo relatado como o agente causador de patologias como endocardite e sepse. O presente trabalho teve por objetivo avaliar quais os possíveis componentes do sistema imune poderiam atuar de maneira protetora contra a infecção por S. aureus em camundongos imunizados intradermicamente. Materiais e métodos: Camundongos C57Bl/6 e A/j foram imunizados intradermicamente com amostras de S. aureus inativadas por calor e, posteriormente, foram desafiados com amostras viáveis em um modelo de bolsão de ar. Nos tempos de 6, 12 e 24 horas após o desafio, a eutanásia ocorreu e o perfil celular do infiltrado inflamatório, bem como a carga bacteriana, foram avaliados no lavado do bolsão de ar. No soro e no lavado foram quantificados anticorpos da classe IgG e a pele do bolsão foi avaliada por técnicas histopatológicas. Pela técnica de ELISA foram quantificadas citocinas presentes no lavado do bolsão, baço e medula. Resultados: Animais imunizados e desafiados com amostras resistentes no modelo de bolsão apresentaram recrutamento celular inflamatório constituído predominantemente por neutrófilos. Além disso, foi observada uma associação entre uma produção de anticorpos IgG e a redução da carga bacteriana em um modelo murino de imunização intradérmica. Ademais, animais imunizados apresentaram menor inflamação no sítio de infecção e uma maior produção local de IL-17A. Em relação as outras citocinas, não foram encontradas diferenças nos tecidos analisados. Discussão: S. aureus é capaz de induzir uma resposta sistêmica, assim como, recrutar células inflamatórias para o sítio de infecção. Porém, animais imunizados tendem a controlar melhor o processo inflamatório, aparentemente por uma correlação entre a produção de anticorpos IgG e a redução da carga bacteriana em um modelo murino de imunização intradérmica. A menor carga bacteriana nos animais imunizados se correlacionou, 10 também, com uma menor inflamação no sítio de infecção e uma maior produção local de IL-17A. Conclusão: A presença de anticorpos IgG2a se correlaciona com diminuição da carga bacteriana em animais imunizados intradermicamente com S. aureus, juntamente com a elevação de IL-17A no modelo de bolsão de ar. / PALMITO, Denisar dos Santos. C57Bl/6 and A/j mice presente diferente inflamatory response patterns after immunization with Staphylococcus aureus and challenge in air pouch model. Master Dissertation - Instituto Multidisciplinar de Saúde, Universidade Federal da Bahia, Vitória da Conquista, 2015. Introduction / Objective: Staphylococcus aureus is the major etiological agent of bacterial infections in humans and is reported as the causative agent of diseases such as sepsis and endocarditis. This study aimed to evaluate which components of the immune system could act protectively against S. aureus infection in mice immunized intradermally. Methods: C57Bl/6 and A/j mice were immunized intradermally with S. aureus strains inactivated by heat and then were challenged with viable strains in an air pouch model. At the times of 6, 12 and 24 hours after challenge, the euthanasia was performed and the cellular profile of the inflammatory infiltrate as well as the bacterial load were evaluated in the air pouch lavages. Serum and lavages of air pouch were quantified for IgG antibodies and the skin was evaluated by histopathological techniques. Cytokines present in air pouch, spleen and bone marrow were quantified by ELISA . Results: Animals immunized and challenged with strains resistant to the air pouch model presented an inflammatory cell recruitment constituted predominantly by neutrophils. Furthermore, it was observed an association between the production of IgG antibodies and reduced the bacterial load in our model of intradermal immunization. In addition, immunized animals showed lower inflammation at the site of infection and increased local production of IL-17A. Regarding the other cytokines, no differences were found in the tissues. Discussion: S. aureus is able to induce a systemic response as well as recruiting inflammatory cells into the infection site. Immunized animals showed a higher control the inflammatory process correlated with the production of IgG antibodies and a reduced bacterial burden in the inflammatory site. The lower bacterial load in animals immunized correlated also with lower inflammation in the site of infection and increased local production of IL-17A. Conclusion: The presence of IgG2a antibodies correlates with a decreased bacterial load in animals immunized intradermally with S. aureus along with the elevation of IL-17A

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Nous avons découvert que les DC pathologiques (LCH DC) qui s’accumulent dans les granulomes de patients atteints d’histiocytose langerhansienne (LCH) produisent l’IL-17A (Coury et al, Nat Med 2008). In vitro, les LCH DC fusionnent en cellules géantes (MGC) sous l’influence de leur production autocrine d’IL-17A. In vivo, les granulomes de LCH DC et MGC détruisent les tissus. Pendant la thèse, nous avons étudié les transcriptomes des monocytes, DC, traitées ou non par l’IL-17A et des LCH DC. L’IL-17A induit BCL2A1, un membre de la famille Bcl-2 qui prolonge la survie des DC. Elle induit aussi les chémokines CCL20 et CCL2, qui regroupent les DC avant leur fusion. L’induction du récepteur nucléaire LXR-α, de protéines impliquées dans le métabolisme, le transport et le stockage des lipides témoignent d’un profond remodelage lipidique. Après la confirmation de ces régulations par PCR et western, les goutelettes lipidiques sont quantifiées à l’huile rouge, puis l’analyse lipidomique révèle l’augmentation de phospholipides, triglycérides, esters de cholestérol et cholestérol par l’IL-17A dans les DC qui sont aussi capables de capturer du palmitate extracellulaire fluorescent. Les transcriptomes des DC traitées à l’IL-17A et des LCH DC sont similaires. La simvastatine qui bloque la synthèse de cholestérol tue les LCH DC. Ce travail établit pour la première fois que l’IL-17A affecte profondément le métabolisme lipidique des DC, une activité qui pourrait avoir d’importantes applications dans les maladies chroniques inflammations associées à une dérégulation lipidique comme l’athérosclérose, l’obésité, la tuberculose et la LCH / We found that the pathological DCs (DC LCH), accumulating in the granulomas of patients affected with Langerhans cell histiocytosis (LCH), produce IL-17A (Coury et al, Nat Med 2008). In vitro, LCH DCs form multinucleated giant cells (MGC) by a fusion process, under the influence of their IL-17A autocrine production. In vivo, granulomas, which are mainly composed of LCH DCs and MGCs, destroy tissues of the patients. During the PhD, we studied the transcriptomes of monocytes, DCs, treated or not with IL-17A, and LCH DCs. IL-17A induceed BCL2A1, a member of the Bcl-2 family that prolonged DC survival. It also induced the CCL2 and CCL20 chemokines that clustered DC, a process required to license DC fusion. The inductions of LXR-α nuclear receptors, proteins involved in metabolism, transport and storage of lipids signed a deep lipid remodeling induced by IL-17A in DCs. We confirmed these regulations by PCR and western studies, then the lipid droplets were quantified after Oil Red-O staining. Further lipidomic analysis revealed an increase of phospholipids, triglycerides, cholesteryl esters and cholesterol by IL-17A in DCs, which are also able to capture extracellular fluorescent palmitate. Transcriptomes of DCs treated with IL-17A and LCH DCs were similar. Simvastatin, which inhibits the synthesis of cholesterol, killed LCH DC. For the first time, this work establishes that IL-17A profoundly affects the lipid metabolism of DCs, an activity that may have important applications in chronic inflammations associated with lipid deregulations such as atherosclerosis, obesity, tuberculosis and LCH

La pandémie de tuberculose (TB) causée par Mycobactérium tuberculosis (Mtb) n’est pas contrôlée par le vaccin vivant BCG. Mtb induit la formation de granulomes qui évoluent vers une réaction inflammatoire exacerbée détruisant le poumon lors de la TB active. Les rôles des polynucléaires neutrophiles (PNN) et de la cytokine inflammatoire IL-17A dans cette évolution sont à clarifier. Nous montrons, chez la souris, que les PNN sont recrutés dans le poumon en deux vagues après infection par Mtb ou BCG. La deuxième vague dépend du récepteur IL-17RA exprimé par les cellules non-hématopoïétiques. Les chimiokines CXCL-1 et 5 attirant les PNN semblent impliquées. Dans le poumon, ces PNN produisent la cytokine immunosuppressive IL-10 qui diminue la production d’IL-17A. Les cellules dendritiques infectées, présentes dans le granulome, sécrètent aussi CXCL-1. Elles attirent les PNN qui produisent de l’IL-10 bloquant la production d’IL-17A mais pas d’IFN-γ. En effet, seuls les lymphocytes CD4+ Th17 expriment le récepteur à l’IL-10. Nos travaux apportent un éclairage nouveau sur les PNN régulateurs dans le contrôle de inflammation due à l’IL-17A lors de la TB. / Tuberculosis (TB) pandemic, caused by Mycobacterium tuberculosis (Mtb), is not controlled by the live vaccine BCG. Mtb induces granuloma formation developing to exacerbated inflammation that destroys the lung during active TB. Roles played by polymorphonuclear neutrophils (PMN) and inflammatory cytokine IL-17A remain ill defined. We show, in the mouse model, that PMN reach the lung in two waves following lung infection with BCG or Mtb. Only the second wave depends on receptor IL-17A expression by non hematopoietic cells. PMN chemoattractants CXCL-1 and 5 seem involved in this late recruitment. In the lung PMN produce immunosuppressive IL-10 that dampens IL-17A production. Mycobacteria infected dendritic cells, present inside granuloma, also secrete CXCL-1. Neutrophils attracted towards infected dendritic cells secrete IL-10 that inhibits IL-17A but not IFN-g production. Indeed, CD4+ Th17 and not Th1 express the IL-10 receptor. Our data shed new light on regulatory PMN in IL-17A-driven lung inflammation during TB.

Dans la tuberculose, Mycobacterium tuberculosis forme des granulomes dans les poumons avec, au centre, des cellules myéloïdes mono et multi-nucléées et autour, des lymphocytes. Nous avons étudié la biologie des cellules géantes dans ces granulomes tuberculeux : formation, mécanismes de survie et fonctions. Notre groupe a publié que l’IL-17A déclenche la fusion des cellules dendritiques (DC). Notre travail démontre que cette cytokine induit BCL2A1/BFL1, qui régule la survie des DC et les chémokines CCL2 et CCL20 qui dirigent le regroupement nécessaire à leur fusion. In situ, l'IL-17A est exprimée par les lymphocytes T de la couronne du granulome tuberculeux. BCL2A1, CCL2 et CCL20 sont exprimés par les cellules myéloïdes mono-et multi-nucléées. Ensuite, nous avons caractérisé le phénotype, les fonctions immunitaires et l'activité microbicide des DC traitées par l'IL-17A. Nous avons trouvé qu’elles co-expriment des marqueurs de DC et de macrophages, conservent les fonctions classiques des DC, synthétisent un profil spécifique d’enzymes destructrices et exercent une microbicidie variable suivant les souches de Mycobactéries. Nous avons nommé GMIC (Giant Myeloid Inflammatory Cell), ces cellules géantes induites par l'IL-17A. Nous proposons qu'elles constituent un nouvel effecteur myéloïde qui contrôle les mycobactéries. Ainsi, l'IL-17A participerait au maintien du cœur myéloïde du granulome tuberculeux en favorisant la formation des cellules géantes possédant des fonctions destructrices et microbicides. Les mécanismes moléculaires que nous avons documentés devraient permettre le développement de nouvelles stratégies thérapeutiques et vaccinales contre la tuberculose. / Tuberculosis, caused by Mycobacterium tuberculosis infection, results in the development of granulomas in affected tissues. These structures are formed by a myeloid cell core including multinucleated giant cells and surrounded by T lymphocytes. We studied mechanisms of survival, formation and functions of giant cells in Mycobacterium granulomas. Previously, our group showed that the cytokine IL-17A induces the fusion of dendritic cells (DC). Here, we identified molecules induced by the IL-17A genetic program in myeloid cells: BFL1 regulated DC survival, while the chemokines CCL2 and CCL20 directed clustering required for DC fusion. In situ, in human TB granulomas, we found that IL-17A was expressed by T lymphocytes while BFL1, CCL2 and CCL20 were expressed by the mono- and multi-nucleated myeloid cells. Then we characterized phenotype, immune functions and microbicidal activity of IL-17A-treated DC and their derived giant cells. They expressed a mixed DC-macrophage phenotype, retained classical DC functions, synthesized several destructive enzymes and had increased and differential microbicidal activities against Mycobacterium species. We named GMIC (giant myeloid inflammatory cells) these IL-17A-dependent giant cells, and propose that they constitute a new inflammatory myeloid effector with potent microbicidal activities. Altogether, our results show that IL-17A may participate in the maintenance of the myeloid core of human tuberculosis granuloma by promoting the formation of GMIC with potent destructive and microbicidal functions. The molecular mechanisms we have documented should help the development of new tuberculosis therapeutic and vaccination strategies.

En dehors des effets cytostatiques ou cytotoxiques sur les cellules tumorales, certaines thérapies anti-cancéreuses peuvent déclencher la mort cellulaire immunogénique, libérant les signaux de danger pour alerter le système immunitaire. Les cellules T CD8+ T (Tc1) productrices d’IFN- et spécifiques de la tumeur sont nécessaires pour le succès de la chimiothérapie et la diminution de la croissance tumorale. L’amorçage d’une réponse bénéfique Tc1 dépend de la sécrétion d'IL-1β par les cellules dendritiques confrontées à des cellules tumorales traitées avec de l’anthracycline libérant de l’ATP. Pour identifier les composants inflammatoires qui lient les réponses immunitaires innées et adaptatives, nous avons analysé l'influence de la chimiothérapie immunogène sur le microenvironnement de la tumeur. Nous avons identifié une up-régulation de gènes associés à la réponse Th1 et Th17 dans un modèle de tumeur répondant au traitement par les anthracyclines par un retard de croissance. En interférant avec les voies IFN- ou l'IL-17A, l'effet thérapeutique de la doxorubicine et l'oxaliplatine a été aboli et le vaccin à base de cellules tumorales mortes ne protège plus les souris de la réintroduction de cellules tumorales vivantes. Nous avons également découvert que des sous-populations distinctes de lymphocytes T  (V4+ et V6+) colonisent des tumeurs peu de temps après la chimiothérapie, où ils ont proliféré et sont devenus producteurs majeurs de l’IL-17 au sein de la tumeur. Nous avons constaté une forte corrélation entre la présence de lymphocytes T  producteurs d’IL-17 ( T17) et de TIL CD8+ (Tc1) dans trois modèles différents de tumeurs traitées par la chimiothérapie ou la radiothérapie. IL-17A agit sur la signalisation en amont de l'IFN- puisqu’un défaut d’expression d’IL-17RA conduit à la perte complète de la production des Tc1 spécifiques de l’antigène. La contribution des cellules  T17 (V4+ et V6+) dans l’effet bénéfique de la chimiothérapie est essentielle puisque les souris V4/6-/-. L’axe IL-1β/IL-1R, mais pas IL-23/IL-23R, est essentielle pour la production d'IL-17 par les cellules T et l’effet bénéfique de la chimiothérapie. Le transfert adoptif de lymphocytes  T peut rétablir l'efficacité de la chimiothérapie dans le modèle de souris IL-17A-/- et améliorer l'effet de la chimiothérapie chez la souris wt, s'ils conservent l'expression de l'IL-1R et de l'IL-17A. Nos résultats suggèrent l’existence d’un axe fonctionnel: DC (IL-1β) → cellules T (IL-17) → Tc1 (IFN-), déclenché par la chimiothérapie induisant la mort des cellules tumorales, phénomène essentiel pour une réponse thérapeutique favorable. Pour renforcer la réponse immunitaire, nous essayons de combiner la chimiothérapie « immunogène » avec le vaccin anti-tumoral en présence d’adjuvants (poly (A:U), l'agoniste de TLR3).Ce type de thérapie séquentielle combinée, appelé VCT, pourrait retarder considérablement la croissance des tumeurs, voire l’éradiquer complètement et établir une protection spécifique à long terme. Pour décortiquer l'effet de la poly (A:U) sur le système immunitaire et sur les cellules tumorales exprimant le TLR3, nous avons effectué un traitement VCT chez la souris nude, TRIF-/- et les souris présentant une diminution de l’expression de TRIF au niveau des cellules tumorales. Ainsi l'effet anti-tumoral de VCT requiert les lymphocytes T et la voie de signalisation TRIF intacte au niveau de l'hôte et des cellules tumorales. Le traitement poly (A:U) peut induire un niveau élevé de production de certaines chimiokines associées à la réponse de type Th1 (CCL5 et CXCL10 ) par les cellules tumorales in vitro et in vivo, ce qui peut influencer négativement et positivement les résultats thérapeutiques. Le découplage de l’action de CCL5 et de XCL10, pourrait améliorer le traitement par la VCT. Notre étude souligne ainsi le rôle des facteurs inflammatoires dérivés de la tumeur et de l’hôte dans la régulation de la réponse immunitaire anti-tumorale. / Besides exerting cytostatic or cytotoxic effects on tumor cells, some anti-cancer therapies (anthracyclines, oxaliplatin, X-Rays) could trigger an immunogenic cell death modality, releasing danger signals to alert immune system. We have shown that tumor-specific IFN- producing CD8+ T cells (Tc1) are mandatory for the success of chemotherapy to prevent tumor outgrowth. Priming of Tc1 response depends on IL-1β secretion by DC confronted with anthracycline-treated tumor cells releasing ATP. To identify the inflammatory components which link innate and cognate immune responses, we analyzed the influence of immunogenic chemotherapy on tumor microenvironment. We found an upregulated Th1- and Th17-related gene expression pattern in growth-retarded tumor after anthracycline treatment. By interfering with IFN- or IL-17A pathways, therapeutic effect of doxorubicin and oxaliplatin was abolished and dying tumor cell-based vaccine lost its efficacy to protect mice from live tumor cell rechallenge. Interestingly, we discovered that distinct subsets of  T lymphocytes (V4+ and V6+) colonized tumors shortly after chemotherapy, where they proliferated and became the dominant IL-17 producers within tumor beds. In three tumor models treated with chemotherapy or radiotherapy, a strong correlation between the presence of IL-17-producing  T ( T17) and IFN--producing CD8+ TIL (Tc1) was discovered. IL-17A signaling acts as upstream of IFN- since defect in IL-17RA led to complete loss of antigen specific Tc1 priming. The contribution of  T17 cells (V4+ and V6+) to chemotherapy is critical as V4/6-/- mice showed reduced sensitivity to chemotherapy and vaccination. Also, tumor infiltrating  T17 and Tc1 cells were reduced to basal level in this strain. IL-1β/IL-1R, but not IL-23/IL-23R, is pivotal for IL-17 production by  T cells and the success of chemotherapy. Importantly, adoptive transfer of  T cells could restore the efficacy of chemotherapy in IL-17A-/- mice and ameliorate the effect of chemotherapy in wild type host, provided that they retain the expression of IL-1R and IL-17A. Our research suggest a DC (IL-1β) →  T cells (IL-17) → Tc1 (IFN-) immune axis triggered by chemotherapy-induced dying tumor cells, which is critical for the favorable therapeutic response. To boost the immune system, we try to combine immunogenic chemotherapy with tumor vaccine in the presence of TLR3 agonist Poly (A:U). This sequential combined therapy, which we named VCT, could significantly retard tumor growth or even completely eradicate tumor and establish long-term protection against rechallenge in highly tumorigenic models. To dissect the effect of Poly (A:U) on immune system and that on TLR3 expressing-tumor cells, we performed VCT treatment in nude mice, TRIF-/- mice and with TRIF-silencing tumors. Interestingly, our results suggested that anti-tumor effect of VCT required T cells and intact TRIF signaling pathway at the level of the host and that of tumor cells. Poly (A:U) treatment could induce high level of CCL5 and CXCL10 production from tumor cells both in vitro and in vivo, which could negatively and positively influence the therapeutic outcome. By uncoupling the effect of CCL5 from that of CXCL10, the VCT treatment can be ameliorated. Our study emphasizes that both tumor and host derived inflammatory factors participate in regulating anti-tumor response. We also highlight that therapeutic application of TLR agonists can be optimized through regulating the profile of chemokines and their downstream signaling events.

L’ozone est un des polluants présents dans l’air que nous respirons. Les pics de ce polluant entrainent une augmentation des hospitalisations et des cas d’exacerbations d’asthme allergique. L’objectif de ce travail est d’étudier plus en détails les mécanismes inflammatoires mis en place après exposition à l’ozone. Cette étude s’est déroulée en trois axes, les deux premiers traitant du rôle de deux alarmines, l’IL-33 et l’IL-1α et le troisième se focalisant sur AhR, un récepteur impliqué dans la réponse à de nombreux polluants. Pour ce faire, des souris ont été exposées à l’ozone selon deux modèles, l’un aigu et l’autre chronique, puis les paramètres inflammatoires, le dommage tissulaire et les difficultés respiratoires ont été évalués. Nous montrons ici qu’une exposition aigüe à l’ozone induit la libération de molécules comme l’IL-33 et l’IL-1α. L’IL-33 agit au niveau de la barrière épithéliale, où elle permet l’expression et le maintien des jonctions serrées, qui sont augmentées en réponse à la pollution à l’ozone. L’IL-33 régule également l’infiltration des neutrophiles, alors que l’IL-1α l’induit. Ensuite nous avons montré que le récepteur AhR est activé après exposition chronique à l’ozone. AhR semble réguler la production de cytokines telles que l’IL-17A et l’IL-22 et ainsi protège d’une trop forte réponse inflammatoire. Pour conclure, nous avons montré que la production d’IL-33 et l’activation du récepteur AhR étaient nécessaires pour contrôler l’inflammation induite par l’ozone, alors que la production d’IL-1α l’induisait. Cette étude aura permis de mettre en évidence de potentielles cibles thérapeutiques pour soulager les maux provoqués par la pollution. / Ozone is a common ambient air polluant. Ozone peaks induce increase of asthma exacerbation, respiratory distress, emergencies and hospital admissions. The aim of this thesis project is to dissect inflammatory mechanisms induced after ozone exposure. This study is conducted according three axes, the first two dealing with the roles of two alarmines, IL-1α and IL-33 and the third is focused on the role of aryl hydrocarbon receptor (AhR), a receptor involved in several pollutant responses. Acute and chronic experimental models of ozone exposure were used to evaluate inflammatory parameters in lung, tissue damage and airway hyperresponsiveness. Here we show that acute ozone exposure induces IL-1α and IL-33 release. IL-33 acts on lung epithelial barrier, allowing the expression and maintenance of tight junctions induced after ozone exposure. Moreover, IL-33 represses neutrophils infiltration while IL-1α induces it. Furthermore we show that AhR is activated after chronic ozone exposure. AhR regulates cytokines production such as IL-17A and IL-22 and plays a protective role against higher inflammation. Overall, IL-33 production and AhR activation are necessary to control ozone-induced inflammation, in contrast to IL-1α. These findings highlight potential therapeutic targets for the treatment of lung inflammation following ozone exposure.

Besides exerting cytostatic or cytotoxic effects on tumor cells, some anti-cancer therapies (anthracyclines, oxaliplatin, X-Rays) could trigger an immunogenic cell death modality, releasing danger signals to alert immune system. We have shown that tumor-specific IFN- producing CD8+ T cells (Tc1) are mandatory for the success of chemotherapy to prevent tumor outgrowth. Priming of Tc1 response depends on IL-1β secretion by DC confronted with anthracycline-treated tumor cells releasing ATP. To identify the inflammatory components which link innate and cognate immune responses, we analyzed the influence of immunogenic chemotherapy on tumor microenvironment. We found an upregulated Th1- and Th17-related gene expression pattern in growth-retarded tumor after anthracycline treatment. By interfering with IFN- or IL-17A pathways, therapeutic effect of doxorubicin and oxaliplatin was abolished and dying tumor cell-based vaccine lost its efficacy to protect mice from live tumor cell rechallenge. Interestingly, we discovered that distinct subsets of  T lymphocytes (V4+ and V6+) colonized tumors shortly after chemotherapy, where they proliferated and became the dominant IL-17 producers within tumor beds. In three tumor models treated with chemotherapy or radiotherapy, a strong correlation between the presence of IL-17-producing  T ( T17) and IFN--producing CD8+ TIL (Tc1) was discovered. IL-17A signaling acts as upstream of IFN- since defect in IL-17RA led to complete loss of antigen specific Tc1 priming. The contribution of  T17 cells (V4+ and V6+) to chemotherapy is critical as V4/6-/- mice showed reduced sensitivity to chemotherapy and vaccination. Also, tumor infiltrating  T17 and Tc1 cells were reduced to basal level in this strain. IL-1β/IL-1R, but not IL-23/IL-23R, is pivotal for IL-17 production by  T cells and the success of chemotherapy. Importantly, adoptive transfer of  T cells could restore the efficacy of chemotherapy in IL-17A-/- mice and ameliorate the effect of chemotherapy in wild type host, provided that they retain the expression of IL-1R and IL-17A. Our research suggest a DC (IL-1β) →  T cells (IL-17) → Tc1 (IFN-) immune axis triggered by chemotherapy-induced dying tumor cells, which is critical for the favorable therapeutic response. To boost the immune system, we try to combine immunogenic chemotherapy with tumor vaccine in the presence of TLR3 agonist Poly (A:U). This sequential combined therapy, which we named VCT, could significantly retard tumor growth or even completely eradicate tumor and establish long-term protection against rechallenge in highly tumorigenic models. To dissect the effect of Poly (A:U) on immune system and that on TLR3 expressing-tumor cells, we performed VCT treatment in nude mice, TRIF-/- mice and with TRIF-silencing tumors. Interestingly, our results suggested that anti-tumor effect of VCT required T cells and intact TRIF signaling pathway at the level of the host and that of tumor cells. Poly (A:U) treatment could induce high level of CCL5 and CXCL10 production from tumor cells both in vitro and in vivo, which could negatively and positively influence the therapeutic outcome. By uncoupling the effect of CCL5 from that of CXCL10, the VCT treatment can be ameliorated. Our study emphasizes that both tumor and host derived inflammatory factors participate in regulating anti-tumor response. We also highlight that therapeutic application of TLR agonists can be optimized through regulating the profile of chemokines and their downstream signaling events.