Isogenic, or inbred, mouse strains are currently the experimental subjects of choice in laboratory studies focused on genetics, pharmacology, and psychological issues. Understanding phenotypic differences in isogenic strains is important in order to interpret experimental results obtained from inbred mouse strains. Four commonly used inbred strains, C57BL/6NHsd (C57), DBA/2NHsd (DBA), 129S2/SvHsd (129), and Balb/cAnHsd (Balb/c), are investigated in this study using four different behavioral tasks that measure locomotor activity and cognitive behavior (Morris Water Maze (MWM), T-maze, and operant autoshaping procedures). In the locomotor activity task 129 mice showed significantly less horizontal ambulation than any other strain, while differences in rearing was seen between all strains, with C57 mice producing the most, and 129 showing the least rearing. Thigmotaxia was seen the most in the 129 strain, less so with the Balb/c and DBA strains, and the least in the C57 mice. In the MWM learning across strains was noted but there was no difference between the strains. In the T-maze the Balb/c strain showed the shortest latency to enter an arm, while the 129 strain showed the longest. As expected they also showed the lowest accuracy and the highest percent time-outs compared to all the other strains. In the autoshaping procedure little difference between the strains was observed. Balb/c mice trended graphically towards higher rates however there was no difference with regard to number of contingent responses or number per strain to reach a criterion of 10 or more contingent reinforcers. Finally, locomotor activity was measured again at the end of the study. The activity results were still similar, although the C57 strain showed a decrease in horizontal ambulation as compared to DBA and Balb/c strains; however, the 129 strain still showed the least activity. These results indicate that there are significant differences in locomotor behavior and cognitive processes in these strains that should be considered when interpreting results from studies using these inbred mouse strains.

Les cellules T invariantes associées aux muqueuse (MAIT) sont des lymphocytes innés caractérisés par l'expression d'un récepteur des cellules T semi-invariant (iTCR) et restreints par la molécule du complexe majeur d'histocompatibilité de classe Ib, MR1. Chez l'homme, les cellules MAIT sont abondantes dans le sang (1 à 10%), l'intestin (3 à 5%) et le foie (20 à 40%) et réagissent contre des métabolites microbiens. En raison de leur rareté dans les souris de laboratoire classiques, les études sur les cellules MAIT murines ont été principalement effectuées sur des souris transgéniques (Tg) pour des TCR MAIT. Cependant, ces cellules MAIT Tg ne récapitulent pas de manière adéquate le phénotype des cellules MAIT humaines. Ici, nous décrivons une souche de souris congénique que nous avons générée qui possède des cellules MAIT qui ressemblent aux cellules MAIT humaines. Nous utilisons cet outil pour étudier les caractéristiques des cellules MAIT murines. L'étude de souches de souris consanguines d'origine sauvage montre que la souche CAST/Ei présente une fréquence des cellules MAIT nettement supérieur à celle retrouvée dans la souche C57BL/6. Un seul locus est impliqué et a été localisé dans la région TCRα. Ceci a permis la génération d'une souche "MAIT" congénique, qui ont été en outre croisé à une souris Tg pour un rapporteur GFP du facteur transcriptionnel RORγt sur la base de données antérieurs montrant que les MAITs humaines expriment ce facteur. Grâce à cet outil, nous montrons que les MAITs murines sont CD4−CD8−/lo, ont un phénotype mémoire effecteurs (CD44+) et coexpriment PLZF et RORγt. Ces MAITs murines sont orientées vers une localisation tissulaire (CCR6+CCR7−) et résident préférentiellement dans les tissus non lymphoïdes périphériques, y compris les poumons, le foie et la peau. Après stimulation du TCR, les MAITs produisent des cytokines TH1/2/17 et sont aussi activées par de antigènes bactériens (par exemple semi-purifié fraction bactérienne ou 5-OP-RU) d'une manière dépendant de MR1. Les MAITs ont une forte expression de récepteurs de cytokines (IL-7R, IL-18Rα, IL-12Rβ) et peuvent ainsi répondre à des cytokines innées. Lors d'une infection expérimentale des voies urinaires, les MAITs migrent vers la vessie et ont une activité protectrice anti-bactérienne. Au total, nos résultats démontrent que les cellules MAIT murines ressemblent étroitement à leurs homologues humains. Ce nouveau modèle murin sera un outil puissant pour faire avancer notre compréhension de la biologie des cellules MAIT en situation normale et pathologique. / Mucosal-associated invariant T cells (MAIT) are innate lymphocytes that express a semi-invariant T cell receptor (iTCR) and are restricted by the major histocompatibility complex (MHC) related molecule, MR1. In human, MAIT cells are abundant in the blood (1-10%), gut (3-5%), and liver (20-40%). They react against microbial-derived riboflavin metabolites that are common in bacteria and yeast. Due to the paucity of MAIT cells in classical inbred laboratory mice, studies on mouse MAIT cells were mostly performed in TCR-transgenic (Tg) mice. However, these Tg MAIT cells do not adequately recapitulate the phenotype of human MAIT cells. Herein, we present a recently generated congenic mouse strain harboring MAIT cells that closely resemble human MAIT cells and use this tool to study the characteristics of natural mouse MAIT cell. An analysis of wild-derived inbred mouse strains revealed that CAST/Ei strain has increased frequency of MAIT cells than C57BL/6 mice. This was linked to a locus on the TCRα region. Introduction of such locus into C57BL/6 mice generated a “MAIT” congenic strain, which were further crossed to Rorc(γt)-GfpTG reporter strain based on previous findings of RORγt expression on human MAIT cells. Using this tool, we show that natural mouse MAIT cells are CD4−CD8−/lo, display an effector memory phenotype (CD44+), and coexpress the transcription factors PLZF and RORγt. They exhibit tissue-homing properties (CCR6+CCR7−) and preferentially reside in peripheral non-lymphoid tissues, including lung, liver, and skin. Upon TCR ligation, MAIT cells produce TH1/2/17 type cytokines and react to bacterial-derived antigens (i.e. semi-purified bacterial fraction or 5-OP-RU) in an MR1-dependent manner. They have high expression of cytokine receptors (IL-7R, IL-18Rα, IL-12Rβ) and may respond to the corresponding innate cytokines. During experimental urinary tract infection, MAIT cells migrate to the bladder and display a protective anti-bacterial activity. Altogether, our results demonstrate that mouse MAIT cells resemble their human counterparts more closely than previously recognized and therefore this new mouse model will be a powerful tool for advancing our understanding of MAIT cell biology in health and disease.

Les cellules T invariantes associées aux muqueuse (MAIT) sont des lymphocytes innés caractérisés par l'expression d'un récepteur des cellules T semi-invariant (iTCR) et restreints par la molécule du complexe majeur d'histocompatibilité de classe Ib, MR1. Chez l'homme, les cellules MAIT sont abondantes dans le sang (1 à 10%), l'intestin (3 à 5%) et le foie (20 à 40%) et réagissent contre des métabolites microbiens. En raison de leur rareté dans les souris de laboratoire classiques, les études sur les cellules MAIT murines ont été principalement effectuées sur des souris transgéniques (Tg) pour des TCR MAIT. Cependant, ces cellules MAIT Tg ne récapitulent pas de manière adéquate le phénotype des cellules MAIT humaines. Ici, nous décrivons une souche de souris congénique que nous avons générée qui possède des cellules MAIT qui ressemblent aux cellules MAIT humaines. Nous utilisons cet outil pour étudier les caractéristiques des cellules MAIT murines. L'étude de souches de souris consanguines d'origine sauvage montre que la souche CAST/Ei présente une fréquence des cellules MAIT nettement supérieur à celle retrouvée dans la souche C57BL/6. Un seul locus est impliqué et a été localisé dans la région TCRα. Ceci a permis la génération d'une souche "MAIT" congénique, qui ont été en outre croisé à une souris Tg pour un rapporteur GFP du facteur transcriptionnel RORγt sur la base de données antérieurs montrant que les MAITs humaines expriment ce facteur. Grâce à cet outil, nous montrons que les MAITs murines sont CD4−CD8−/lo, ont un phénotype mémoire effecteurs (CD44+) et coexpriment PLZF et RORγt. Ces MAITs murines sont orientées vers une localisation tissulaire (CCR6+CCR7−) et résident préférentiellement dans les tissus non lymphoïdes périphériques, y compris les poumons, le foie et la peau. Après stimulation du TCR, les MAITs produisent des cytokines TH1/2/17 et sont aussi activées par de antigènes bactériens (par exemple semi-purifié fraction bactérienne ou 5-OP-RU) d'une manière dépendant de MR1. Les MAITs ont une forte expression de récepteurs de cytokines (IL-7R, IL-18Rα, IL-12Rβ) et peuvent ainsi répondre à des cytokines innées. Lors d'une infection expérimentale des voies urinaires, les MAITs migrent vers la vessie et ont une activité protectrice anti-bactérienne. Au total, nos résultats démontrent que les cellules MAIT murines ressemblent étroitement à leurs homologues humains. Ce nouveau modèle murin sera un outil puissant pour faire avancer notre compréhension de la biologie des cellules MAIT en situation normale et pathologique. / Mucosal-associated invariant T cells (MAIT) are innate lymphocytes that express a semi-invariant T cell receptor (iTCR) and are restricted by the major histocompatibility complex (MHC) related molecule, MR1. In human, MAIT cells are abundant in the blood (1-10%), gut (3-5%), and liver (20-40%). They react against microbial-derived riboflavin metabolites that are common in bacteria and yeast. Due to the paucity of MAIT cells in classical inbred laboratory mice, studies on mouse MAIT cells were mostly performed in TCR-transgenic (Tg) mice. However, these Tg MAIT cells do not adequately recapitulate the phenotype of human MAIT cells. Herein, we present a recently generated congenic mouse strain harboring MAIT cells that closely resemble human MAIT cells and use this tool to study the characteristics of natural mouse MAIT cell. An analysis of wild-derived inbred mouse strains revealed that CAST/Ei strain has increased frequency of MAIT cells than C57BL/6 mice. This was linked to a locus on the TCRα region. Introduction of such locus into C57BL/6 mice generated a “MAIT” congenic strain, which were further crossed to Rorc(γt)-GfpTG reporter strain based on previous findings of RORγt expression on human MAIT cells. Using this tool, we show that natural mouse MAIT cells are CD4−CD8−/lo, display an effector memory phenotype (CD44+), and coexpress the transcription factors PLZF and RORγt. They exhibit tissue-homing properties (CCR6+CCR7−) and preferentially reside in peripheral non-lymphoid tissues, including lung, liver, and skin. Upon TCR ligation, MAIT cells produce TH1/2/17 type cytokines and react to bacterial-derived antigens (i.e. semi-purified bacterial fraction or 5-OP-RU) in an MR1-dependent manner. They have high expression of cytokine receptors (IL-7R, IL-18Rα, IL-12Rβ) and may respond to the corresponding innate cytokines. During experimental urinary tract infection, MAIT cells migrate to the bladder and display a protective anti-bacterial activity. Altogether, our results demonstrate that mouse MAIT cells resemble their human counterparts more closely than previously recognized and therefore this new mouse model will be a powerful tool for advancing our understanding of MAIT cell biology in health and disease.

Les cellules T invariantes associées aux muqueuse (MAIT) sont des lymphocytes innés caractérisés par l'expression d'un récepteur des cellules T semi-invariant (iTCR) et restreints par la molécule du complexe majeur d'histocompatibilité de classe Ib, MR1. Chez l'homme, les cellules MAIT sont abondantes dans le sang (1 à 10%), l'intestin (3 à 5%) et le foie (20 à 40%) et réagissent contre des métabolites microbiens. En raison de leur rareté dans les souris de laboratoire classiques, les études sur les cellules MAIT murines ont été principalement effectuées sur des souris transgéniques (Tg) pour des TCR MAIT. Cependant, ces cellules MAIT Tg ne récapitulent pas de manière adéquate le phénotype des cellules MAIT humaines. Ici, nous décrivons une souche de souris congénique que nous avons générée qui possède des cellules MAIT qui ressemblent aux cellules MAIT humaines. Nous utilisons cet outil pour étudier les caractéristiques des cellules MAIT murines. L'étude de souches de souris consanguines d'origine sauvage montre que la souche CAST/Ei présente une fréquence des cellules MAIT nettement supérieur à celle retrouvée dans la souche C57BL/6. Un seul locus est impliqué et a été localisé dans la région TCRα. Ceci a permis la génération d'une souche "MAIT" congénique, qui ont été en outre croisé à une souris Tg pour un rapporteur GFP du facteur transcriptionnel RORγt sur la base de données antérieurs montrant que les MAITs humaines expriment ce facteur. Grâce à cet outil, nous montrons que les MAITs murines sont CD4−CD8−/lo, ont un phénotype mémoire effecteurs (CD44+) et coexpriment PLZF et RORγt. Ces MAITs murines sont orientées vers une localisation tissulaire (CCR6+CCR7−) et résident préférentiellement dans les tissus non lymphoïdes périphériques, y compris les poumons, le foie et la peau. Après stimulation du TCR, les MAITs produisent des cytokines TH1/2/17 et sont aussi activées par de antigènes bactériens (par exemple semi-purifié fraction bactérienne ou 5-OP-RU) d'une manière dépendant de MR1. Les MAITs ont une forte expression de récepteurs de cytokines (IL-7R, IL-18Rα, IL-12Rβ) et peuvent ainsi répondre à des cytokines innées. Lors d'une infection expérimentale des voies urinaires, les MAITs migrent vers la vessie et ont une activité protectrice anti-bactérienne. Au total, nos résultats démontrent que les cellules MAIT murines ressemblent étroitement à leurs homologues humains. Ce nouveau modèle murin sera un outil puissant pour faire avancer notre compréhension de la biologie des cellules MAIT en situation normale et pathologique. / Mucosal-associated invariant T cells (MAIT) are innate lymphocytes that express a semi-invariant T cell receptor (iTCR) and are restricted by the major histocompatibility complex (MHC) related molecule, MR1. In human, MAIT cells are abundant in the blood (1-10%), gut (3-5%), and liver (20-40%). They react against microbial-derived riboflavin metabolites that are common in bacteria and yeast. Due to the paucity of MAIT cells in classical inbred laboratory mice, studies on mouse MAIT cells were mostly performed in TCR-transgenic (Tg) mice. However, these Tg MAIT cells do not adequately recapitulate the phenotype of human MAIT cells. Herein, we present a recently generated congenic mouse strain harboring MAIT cells that closely resemble human MAIT cells and use this tool to study the characteristics of natural mouse MAIT cell. An analysis of wild-derived inbred mouse strains revealed that CAST/Ei strain has increased frequency of MAIT cells than C57BL/6 mice. This was linked to a locus on the TCRα region. Introduction of such locus into C57BL/6 mice generated a “MAIT” congenic strain, which were further crossed to Rorc(γt)-GfpTG reporter strain based on previous findings of RORγt expression on human MAIT cells. Using this tool, we show that natural mouse MAIT cells are CD4−CD8−/lo, display an effector memory phenotype (CD44+), and coexpress the transcription factors PLZF and RORγt. They exhibit tissue-homing properties (CCR6+CCR7−) and preferentially reside in peripheral non-lymphoid tissues, including lung, liver, and skin. Upon TCR ligation, MAIT cells produce TH1/2/17 type cytokines and react to bacterial-derived antigens (i.e. semi-purified bacterial fraction or 5-OP-RU) in an MR1-dependent manner. They have high expression of cytokine receptors (IL-7R, IL-18Rα, IL-12Rβ) and may respond to the corresponding innate cytokines. During experimental urinary tract infection, MAIT cells migrate to the bladder and display a protective anti-bacterial activity. Altogether, our results demonstrate that mouse MAIT cells resemble their human counterparts more closely than previously recognized and therefore this new mouse model will be a powerful tool for advancing our understanding of MAIT cell biology in health and disease.

The majority of genetic differences between species and individuals have been hypothesised to impact on the regulation, rather than the structure, of genes. As the details of genetic variation are uncovered by the various genome sequencing projects, understanding the functional effects on gene regulation will be key to uncovering the molecular mechanisms underying the genesis and inheritance of common phenotypes, such as complex human disease and commercially important traits in plants and animals. Unlike coding sequence polymorphisms, genetic variants affecting gene expression will reside in the transcriptional machinery and its regulatory inputs. As these are largely specific to cell- or tissue-types, we would expect that regulatory variants will also affect final mRNA levels in a tissue specific manner. Genetic variation between individuals may therefore be more complex than the sum total of sequence differences between them. Demonstrating this hypothesis is the main focus of this thesis. We use microarrays to measure mRNA levels of approximately 22,000 transcripts in inbred and recombinant inbred strains of mice, and present compelling evidence that the genetic influences on these levels are tissue-specific in at least 85% of cases. We uncover two loci which apparently influence transcript levels of multiple genes in a tissue-specific manner. We also present evidence that failure of microarray data normalisation may cause spurious linkage of expression phenotypes leading to erroneous biological conclusions, and detail a novel, extensible mathematical framework for performing tailored normalisation which can remove such systematic bias. The wider context of these results is then discussed.

Variation at regulatory elements, identified through hypersensitivity to digestion by Deoxyribonuclease I (DNase I), is believed to contribute to variation in complex traits, but the extent and consequences of this variation are poorly characterized. To investigate the relationship between sequence variation, and the functional consequences of variation in chromatin accessibility, genome-wide DNase I hypersensitive sites (DHS) of terminally differentiated erythroblasts were studied in eight inbred strains of mice studied (A/J, AKR/J, BALBc/J, C3H/HeJ, C57BL/6J, CBA/J, DBA/2J, and LP/J). These strains were selected because of the availability of their genome sequence and quantitative trait loci (QTL) data. After confirming that next generation sequencing could identify DNase I hypersensitive sites with high sensitivity and specificity, and that differential peaks could be found, an automated peak calling pipeline was developed and optimized. 36,693 DHS peaks were identified covering 9.1 Mb (0.29%) of mouse genome. There was no indication of within strain variation. Between strains reproducible variation was observed at approximately 5% of DNase hypersensitive sites (1,397 DHSs). Variable DHSs were more likely to be enhancers than promoters and less likely to occur at conserved regions of the genome. Only 36% of such variable DHSs contain a sequence variant predictive of site variation and 12% contain at least one variant that disrupts transcription factor binding sites. The majority (86%) of variable DHSs differ in size/shape and the remaining 14% demonstrate discrete variation in single peak or cluster of peaks. Sequence variants within variable DHS are more likely to be associated with complex traits than those in non-variant DHS, and variants associated with complex traits preferentially occur in enhancer-like elements. Changes at a small proportion (7%) of discretely variable DHS are associated with changes in nearby transcriptional activity. Our results show that whilst DNA sequence variation is not the major determinant of variation in open chromatin, where such variants exist they are likely to be causal for complex traits.

Muitos estudos de câncer têm sido desenvolvidos, mas os mecanismos moleculares da tumorigênese e a resposta imune contra tumores não foi completamente elucidada. RMAS é uma linhagem celular mutante derivada de RMA. Ao contrário da última, RMAS é deficiente de MHC I e, portanto, é avlvo de células NK. O objetivo deste trabalho foi o uso deste par de células para estabelecer modelos murinos que possam ser usados para entender a resposta imune entre células CD8 e NK contra tumor e investigar o efeito da expressão de moléculas antiapoptóticas no comportamento tumoral in vivo. Essa abordagem pode prover informações relevantes para o desenvolvimento de novas terapias. Para desenvolver células EGFP, foi usado um vetor retroviral bicistrônico contendo o gene Egfp. Para desenvolver os modelos experimentais, camundongos C57BL6 WT foram injetados iv com diferentes números de células e curvas de sobrevivência foram geradas. Os padrões de doença e infiltração tumoral foram observadas por análises macroscópica, microscópica e por detecção de EGFP em tecidos. In vivo, células RMA. induziram paralisia enquanto RMA-S.Egfp, ascite. RMA.Egfp infiltrou a medula óssea enquanto RMA-S.Egfp, tecidos diferentes como fígado, rins e peritôneo, mas não a medula óssea. Os sinais clínicos apareceram após 15 dias da inoculação de >104 células e a morte, em 30 dias. Números <103 células não induziram doença nem morte, mas protegeram de ambas quando re-inoculadas 106 células RMA.Egfp. Camundongos CD4KO e CD8KO paralisaram e morreram antes do que os WT. Células RMA.BclW.Egfp foram mais resistentes a apoptose do que células RMA.Egfp in vitro e provocaram características clínicas piores: paralisia e morte anteriores, inchaço de membros e hemorragia de fígado e rins. / Many cancer studies have been developed, however the molecular mechanisms of tumorigenesis and immune responses to tumor is not completely elucidated. RMAS cells are a mutant lymphoma line derived from RMA cells. In contrast to the latter, RMAS are deficient in MHCI and, therefore, are targets for NK cells. Our aims were use these pair of cells to establish mouse models that can be used to understand CD8T vs NK cell immune responses to tumors and investigate the effect of expression of antiapoptotic molecules in tumor behavior in vivo. The combination of these approaches should provide relevant information for the development of novel immunotherapy. To develop EGFP cells we used a bicistronic retroviral vector containing Egfp gene. To develop the experimental models, WT C57BL/6 mice were iv injected with different cell numbers and survival curves were produced. In addition, clinical features and tumor spread was observed by macroscopy, microscopy and EGFP detection of tumor cell analysis in tissues. When injected in vivo, RMA.Egfp cells induced progressive paralysis while RMA-S.Egfp promoted ascites. RMA.Egfp cells infiltrated the bone marrow, while RMA-S.Egfp were found in different tissues such as liver, kidney and the peritoneum cavity, but were not found in bone marrow. The symptoms appeared 15 days post injection of >104 cells and the death was 30 days. Numbers of <103 cells do not induced pathology or death, but protected to paralysis and death when re-injected 106 RMA.Egfp cells. CD4KO and CD8KO mice showed paralysis and death earlier than WT mice. RMA.BclW.Egfp cells were more resistant to apoptosis than RMA.Egfp in vitro and induced worse clinical features in vivo: earlier paralysis and death, swelling of members, haemorragia of liver and kidneys.

Muitos estudos de câncer têm sido desenvolvidos, mas os mecanismos moleculares da tumorigênese e a resposta imune contra tumores não foi completamente elucidada. RMAS é uma linhagem celular mutante derivada de RMA. Ao contrário da última, RMAS é deficiente de MHC I e, portanto, é avlvo de células NK. O objetivo deste trabalho foi o uso deste par de células para estabelecer modelos murinos que possam ser usados para entender a resposta imune entre células CD8 e NK contra tumor e investigar o efeito da expressão de moléculas antiapoptóticas no comportamento tumoral in vivo. Essa abordagem pode prover informações relevantes para o desenvolvimento de novas terapias. Para desenvolver células EGFP, foi usado um vetor retroviral bicistrônico contendo o gene Egfp. Para desenvolver os modelos experimentais, camundongos C57BL6 WT foram injetados iv com diferentes números de células e curvas de sobrevivência foram geradas. Os padrões de doença e infiltração tumoral foram observadas por análises macroscópica, microscópica e por detecção de EGFP em tecidos. In vivo, células RMA. induziram paralisia enquanto RMA-S.Egfp, ascite. RMA.Egfp infiltrou a medula óssea enquanto RMA-S.Egfp, tecidos diferentes como fígado, rins e peritôneo, mas não a medula óssea. Os sinais clínicos apareceram após 15 dias da inoculação de >104 células e a morte, em 30 dias. Números <103 células não induziram doença nem morte, mas protegeram de ambas quando re-inoculadas 106 células RMA.Egfp. Camundongos CD4KO e CD8KO paralisaram e morreram antes do que os WT. Células RMA.BclW.Egfp foram mais resistentes a apoptose do que células RMA.Egfp in vitro e provocaram características clínicas piores: paralisia e morte anteriores, inchaço de membros e hemorragia de fígado e rins. / Many cancer studies have been developed, however the molecular mechanisms of tumorigenesis and immune responses to tumor is not completely elucidated. RMAS cells are a mutant lymphoma line derived from RMA cells. In contrast to the latter, RMAS are deficient in MHCI and, therefore, are targets for NK cells. Our aims were use these pair of cells to establish mouse models that can be used to understand CD8T vs NK cell immune responses to tumors and investigate the effect of expression of antiapoptotic molecules in tumor behavior in vivo. The combination of these approaches should provide relevant information for the development of novel immunotherapy. To develop EGFP cells we used a bicistronic retroviral vector containing Egfp gene. To develop the experimental models, WT C57BL/6 mice were iv injected with different cell numbers and survival curves were produced. In addition, clinical features and tumor spread was observed by macroscopy, microscopy and EGFP detection of tumor cell analysis in tissues. When injected in vivo, RMA.Egfp cells induced progressive paralysis while RMA-S.Egfp promoted ascites. RMA.Egfp cells infiltrated the bone marrow, while RMA-S.Egfp were found in different tissues such as liver, kidney and the peritoneum cavity, but were not found in bone marrow. The symptoms appeared 15 days post injection of >104 cells and the death was 30 days. Numbers of <103 cells do not induced pathology or death, but protected to paralysis and death when re-injected 106 RMA.Egfp cells. CD4KO and CD8KO mice showed paralysis and death earlier than WT mice. RMA.BclW.Egfp cells were more resistant to apoptosis than RMA.Egfp in vitro and induced worse clinical features in vivo: earlier paralysis and death, swelling of members, haemorragia of liver and kidneys.

A pandemia de AIDS é um dos principais problemas de saúde pública no mundo e demanda o desenvolvimento de uma vacina eficaz. Uma abordagem vacinal ideal, baseada em resposta celular contra o HIV-1, deveria induzir uma resposta imune mediada tanto por células T CD4+ quanto CD8+. A diversidade genética do HIV-1 é uma grande preocupação para o desenvolvimento de uma vacina e sequências consenso têm sido utilizadas a fim de contornar a barreira imposta por essa diversidade. A escolha apropriada dos antígenos a comporem as construções vacinas também é relevante, visto que proteínas como Gag e Vif têm se mostrado bastante imunogênicas, enquanto alguns trabalhos têm demonstrado que Env possui características imunossupressoras e que respostas celulares contra esse antígeno podem ser danosas aos indivíduos vacinados. Nosso grupo demonstrou que uma vacina de DNA (HIVBr18) codificando 18 peptídeos para linfócitos T CD4+, promíscuos (capazes de se ligarem a múltiplas moléculas HLA-DR) e conservados na sequência consenso do subtipo B do HIV-1 foi capaz de induzir uma resposta celular ampla, polifuncional e de longa duração em camundongos BALB/c e transgênicos para moléculas HLA. Neste trabalho identificamos 34 peptídeos potencialmente reconhecidos por linfócitos T CD4+, promíscuos e conservados na sequência consenso dos consensos do grupo M do HIV-1. Uma vacina de DNA (HIVBr27) codificando 27 dos 34 peptídeos (exceto os 7 peptídeos de Env identificados) induziu uma resposta mais ampla e de maior magnitude que a vacina HIVBr18 em camundongos BALB/c. Além disso, a vacina HIVBr27 induziu maior frequência de linfócitos T CD4+ e CD8+ polifuncionais, capazes de proliferar e produzir as citocinas IFN-gama e TNF-alfa. Desenvolvemos também uma vacina de DNA (HIVenv7) codificando os 7 peptídeos de Env do HIV-1 identificados. A co-imunização de HIVenv7+HIVBr27 reduziu a amplitude da resposta celular contra peptídeos codificados pela vacina HIVBr27. Além disso, a co-imunização reduziu a magnitude da resposta e a frequência de linfócitos T CD4+ e CD8+ polifuncionais contra o pool de 27 peptídeos codificados por essa vacina. A vacina HIVBr27, desenhada para induzir uma resposta de linfócitos T CD4+ ampla e intensa contra peptídeos promíscuos e conservados da sequência consenso dos consensos do grupo M do HIV-1, é mais imunogênica e mais completa que a vacina HIVBr18, tendo potencial de conferir, em grande cobertura populacional, imunidade contra os diversos subtipos circulantes do vírus. O fenômeno observado na co-imunização com HIVenv7 sugere que a inclusão do envelope em imunógenos contra o HIV-1 possa ser prejudicial. Por outro lado, isto faz desse plasmídeo um alvo promissor para terapias imunológicas que visem indução de imunossupressão / The AIDS pandemic is a worldwide major public health problem and requires the development of an effective vaccine. An ideal vaccine approach based on cellular immune responses against HIV-1 should induce an immune response mediated by both CD4+ and CD8+ T cells. HIV-1 genetic diversity is a major concern for developing a vaccine and consensus sequences have been used to circumvent the barrier posed by this diversity. The appropriate choice of antigens to compose the vaccines is also relevant, since proteins such as Gag and Vif have been shown to be immunogenic, while some studies have shown that Env has immunosuppressive characteristics and cellular responses against this antigen can be harmful to vaccinated individuals. Our group has demonstrated that a DNA vaccine (HIVBr18) encoding promiscuous multiple HLA-DR binding, conserved B-subtype HIV-1 CD4+ T cell epitopes was able to induce a broad, polyfunctional and long lasting T cell response in BALB/c and HLA transgenic mice. In this work we identified 34 promiscuous and conserved sequences within the group M HIV-1 consensus of the consensus sequence, potentially recognized by CD4+ T cells. A DNA vaccine (HIVBr27) encoding 27 of the 34 peptides (except the 7 Env identified peptides) induced a broader and higher magnitude T cell response than HIVBr18 vaccine in BALB/c mice. Moreover, the vaccine HIVBr27 induced a higher frequency of polyfunctional CD4+ and CD8+ T cells, able to proliferate and produce the cytokines IFN-gama and TNF-alfa. We also developed a DNA vaccine (HIVenv7) encoding the 7 HIV-1 Env identified peptides. Co-immunization with HIVenv7+HIVBr27 reduced the breadth of the cellular immune response against the HIVBr27 encoded peptides. Besides, co-imunization reduced the magnitude of the response and the frequency of polyfunctional CD4+ and CD8+ T cells against the pool of 27 peptides encoded by this vaccine. The HIVBr27 vaccine, designed to induce a broad and intense CD4+ T cell response against promiscuous and conserved peptides within the group M HIV-1 consensus of the consensus sequence, is more immunogenic and more complete than the vaccine HIVBr18, having the potential to provide, with wide population coverage, immunity against various circulating subtypes of the virus. The phenomenon observed in the co-immunization with HIVenv7 suggests that the inclusion of the envelope in immunogens against HIV-1 may be harmful. On the other hand, these results suggest that HIVenv7 is a promising target for immune therapies aimed at inducing immunosuppression

A pandemia de AIDS é um dos principais problemas de saúde pública no mundo e demanda o desenvolvimento de uma vacina eficaz. Uma abordagem vacinal ideal, baseada em resposta celular contra o HIV-1, deveria induzir uma resposta imune mediada tanto por células T CD4+ quanto CD8+. A diversidade genética do HIV-1 é uma grande preocupação para o desenvolvimento de uma vacina e sequências consenso têm sido utilizadas a fim de contornar a barreira imposta por essa diversidade. A escolha apropriada dos antígenos a comporem as construções vacinas também é relevante, visto que proteínas como Gag e Vif têm se mostrado bastante imunogênicas, enquanto alguns trabalhos têm demonstrado que Env possui características imunossupressoras e que respostas celulares contra esse antígeno podem ser danosas aos indivíduos vacinados. Nosso grupo demonstrou que uma vacina de DNA (HIVBr18) codificando 18 peptídeos para linfócitos T CD4+, promíscuos (capazes de se ligarem a múltiplas moléculas HLA-DR) e conservados na sequência consenso do subtipo B do HIV-1 foi capaz de induzir uma resposta celular ampla, polifuncional e de longa duração em camundongos BALB/c e transgênicos para moléculas HLA. Neste trabalho identificamos 34 peptídeos potencialmente reconhecidos por linfócitos T CD4+, promíscuos e conservados na sequência consenso dos consensos do grupo M do HIV-1. Uma vacina de DNA (HIVBr27) codificando 27 dos 34 peptídeos (exceto os 7 peptídeos de Env identificados) induziu uma resposta mais ampla e de maior magnitude que a vacina HIVBr18 em camundongos BALB/c. Além disso, a vacina HIVBr27 induziu maior frequência de linfócitos T CD4+ e CD8+ polifuncionais, capazes de proliferar e produzir as citocinas IFN-gama e TNF-alfa. Desenvolvemos também uma vacina de DNA (HIVenv7) codificando os 7 peptídeos de Env do HIV-1 identificados. A co-imunização de HIVenv7+HIVBr27 reduziu a amplitude da resposta celular contra peptídeos codificados pela vacina HIVBr27. Além disso, a co-imunização reduziu a magnitude da resposta e a frequência de linfócitos T CD4+ e CD8+ polifuncionais contra o pool de 27 peptídeos codificados por essa vacina. A vacina HIVBr27, desenhada para induzir uma resposta de linfócitos T CD4+ ampla e intensa contra peptídeos promíscuos e conservados da sequência consenso dos consensos do grupo M do HIV-1, é mais imunogênica e mais completa que a vacina HIVBr18, tendo potencial de conferir, em grande cobertura populacional, imunidade contra os diversos subtipos circulantes do vírus. O fenômeno observado na co-imunização com HIVenv7 sugere que a inclusão do envelope em imunógenos contra o HIV-1 possa ser prejudicial. Por outro lado, isto faz desse plasmídeo um alvo promissor para terapias imunológicas que visem indução de imunossupressão / The AIDS pandemic is a worldwide major public health problem and requires the development of an effective vaccine. An ideal vaccine approach based on cellular immune responses against HIV-1 should induce an immune response mediated by both CD4+ and CD8+ T cells. HIV-1 genetic diversity is a major concern for developing a vaccine and consensus sequences have been used to circumvent the barrier posed by this diversity. The appropriate choice of antigens to compose the vaccines is also relevant, since proteins such as Gag and Vif have been shown to be immunogenic, while some studies have shown that Env has immunosuppressive characteristics and cellular responses against this antigen can be harmful to vaccinated individuals. Our group has demonstrated that a DNA vaccine (HIVBr18) encoding promiscuous multiple HLA-DR binding, conserved B-subtype HIV-1 CD4+ T cell epitopes was able to induce a broad, polyfunctional and long lasting T cell response in BALB/c and HLA transgenic mice. In this work we identified 34 promiscuous and conserved sequences within the group M HIV-1 consensus of the consensus sequence, potentially recognized by CD4+ T cells. A DNA vaccine (HIVBr27) encoding 27 of the 34 peptides (except the 7 Env identified peptides) induced a broader and higher magnitude T cell response than HIVBr18 vaccine in BALB/c mice. Moreover, the vaccine HIVBr27 induced a higher frequency of polyfunctional CD4+ and CD8+ T cells, able to proliferate and produce the cytokines IFN-gama and TNF-alfa. We also developed a DNA vaccine (HIVenv7) encoding the 7 HIV-1 Env identified peptides. Co-immunization with HIVenv7+HIVBr27 reduced the breadth of the cellular immune response against the HIVBr27 encoded peptides. Besides, co-imunization reduced the magnitude of the response and the frequency of polyfunctional CD4+ and CD8+ T cells against the pool of 27 peptides encoded by this vaccine. The HIVBr27 vaccine, designed to induce a broad and intense CD4+ T cell response against promiscuous and conserved peptides within the group M HIV-1 consensus of the consensus sequence, is more immunogenic and more complete than the vaccine HIVBr18, having the potential to provide, with wide population coverage, immunity against various circulating subtypes of the virus. The phenomenon observed in the co-immunization with HIVenv7 suggests that the inclusion of the envelope in immunogens against HIV-1 may be harmful. On the other hand, these results suggest that HIVenv7 is a promising target for immune therapies aimed at inducing immunosuppression