Molecular and Cellular Mechanisms Modulating Trained Immunity by Various Cell Types in Response to Pathogen Encounter.

The induction of trained immunity represents an emerging concept defined as the ability of innate immune cells to acquire a memory phenotype, which is a typical hallmark of the adaptive response. Key points modulated during the establishment of trained immunity include epigenetic, metabolic and functional changes in different innate-immune and non-immune cells. Regarding to epigenetic changes, it has been described that long non-coding RNAs (LncRNAs) act as molecular scaffolds to allow the assembly of chromatin-remodeling complexes that catalyze epigenetic changes on chromatin. On the other hand, relevant metabolic changes that occur during this process include increased glycolytic rate and the accumulation of metabolites from the tricarboxylic acid (TCA) cycle, which subsequently regulate the activity of histone-modifying enzymes that ultimately drive epigenetic changes. Functional consequences of established trained immunity include enhanced cytokine production, increased antigen presentation and augmented antimicrobial responses. In this article, we will discuss the current knowledge regarding the ability of different cell subsets to acquire a trained immune phenotype and the molecular mechanisms involved in triggering such a response. This knowledge will be helpful for the development of broad-spectrum therapies against infectious diseases based on the modulation of epigenetic and metabolic cues regulating the development of trained immunity.

Large-Scale Gene Expression Signatures Reveal a Microbicidal Pattern of Activation in Mycobacterium leprae-Infected Monocyte-Derived Macrophages With Low Multiplicity of Infection.

Leprosy is a disease with a clinical spectrum of presentations that is also manifested in diverse histological features. At one pole, lepromatous lesions (L-pole) have phagocytic foamy macrophages heavily parasitized with freely multiplying intracellular Mycobacterium leprae. At the other pole, the presence of epithelioid giant cells and granulomatous formation in tuberculoid lesions (T-pole) lead to the control of M. leprae replication and the containment of its spread. The mechanism that triggers this polarization is unknown, but macrophages are central in this process. Over the past few years, leprosy has been studied using large scale techniques to shed light on the basic pathways that, upon infection, rewire the host cellular metabolism and gene expression. M. leprae is particularly peculiar as it invades Schwann cells in the nerves, reprogramming their gene expression leading to a stem-like cell phenotype. This modulatory behavior exerted by M. leprae is also observed in skin macrophages. Here, we used live M. leprae to infect (10:1 multiplicity of infection) monocyte-derived macrophages (MDMs) for 48 h and analyzed the whole gene expression profile using microarrays. In this model, we observe an intense upregulation of genes consistent with a cellular immune response, with enriched pathways including peptide and protein secretion, leukocyte activation, inflammation, and cellular divalent inorganic cation homeostasis. Among the most differentially expressed genes (DEGs) are CCL5/RANTES and CYP27B1, and several members of the metallothionein and metalloproteinase families. This is consistent with a proinflammatory state that would resemble macrophage rewiring toward granulomatous formation observed at the T-pole. Furthermore, a comparison with a dataset retrieved from the Gene Expression Omnibus of M. leprae-infected Schwann cells (MOI 100:1) showed that the patterns among the DEGs are highly distinct, as the Schwann cells under these conditions had a scavenging and phagocytic gene profile similar to M2-like macrophages, with enriched pathways rearrangements in the cytoskeleton, lipid and cholesterol metabolism and upregulated genes including MVK, MSMO1, and LACC1/FAMIN. In summary, macrophages may have a central role in defining the paradigmatic cellular (T-pole) vs. humoral (L-pole) responses and it is likely that the multiplicity of infection and genetic polymorphisms in key genes are gearing this polarization.

Immune cell infiltration features and related marker genes in lung cancer based on single-cell RNA-seq.

PURPOSE: Immune cells in the immune microenvironment of lung cancer have a great impact on the development of lung cancer. Our purpose was to analyze the immune cell infiltration features and related marker genes for lung cancer. METHODS: Single cell RNA sequencing data of 11,485 lung cancer cells were retrieved from the Gene Expression Omnibus. After quality control and data normalization, cell clustering was performed using the Seurat package. Based on the marker genes of each cell type from the CellMarker database, each cell was divided into G1, G2M, and S phases. Then, differential expression and functional enrichment analyses were performed. CIBERSORT was used to reconstruct immune cell types. RESULTS: Following cell filtering, highly variable genes were identified for all cells. 14 cell types were clustered. Among them, CD4 + T cell, B cell, plasma cell, natural killer cell and cancer stem cell were the top five cell types. Up-regulated genes were mainly enriched in immune-related biological processes and pathways. Using CIBERSORT, we identified the significantly higher fractions of naïve B cell, memory CD4 + T cell, T follicular helper cell, T regulatory helper cell and M1 macrophage in lung cancer tissues compared to normal tissues. Furthermore, the fractions of resting NK cell, monocyte, M0 macrophage, resting mast cell, eosinophil and neutrophil were significantly lower in tumor tissues than normal tissues. CONCLUSION: Our findings dissected the immune cell infiltration features and related marker genes for lung cancer, which might provide novel insights for the immunotherapy of lung cancer.

Large-scale gene expression signatures reveal a microbicidal pattern of activation in Mycobacterium leprae-infected monocyte-derived macrophages with low multiplicity of infection

Leprosy is a disease with a clinical spectrum of presentations that is also manifested in diverse histological features. At one pole, lepromatous lesions (L-pole) have phagocytic foamy macrophages heavily parasitized with freely multiplying intracellular Mycobacterium leprae. At the other pole, the presence of epithelioid giant cells and granulomatous formation in tuberculoid lesions (T-pole) lead to the control of M. leprae replication and the containment of its spread. The mechanism that triggers this polarization is unknown, but macrophages are central in this process. Over the past few years, leprosy has been studied using large scale techniques to shed light on the basic pathways that, upon infection, rewire the host cellular metabolism and gene expression. M. leprae is particularly peculiar as it invades Schwann cells in the nerves, reprogramming their gene expression leading to a stem-like cell phenotype. This modulatory behavior exerted by M. leprae is also observed in skin macrophages. Here, we used live M. leprae to infect (10:1 multiplicity of infection) monocyte-derived macrophages (MDMs) for 48 h and analyzed the whole gene expression profile using microarrays. In this model, we observe an intense upregulation of genes consistent with a cellular immune response, with enriched pathways including peptide and protein secretion, leukocyte activation, inflammation, and cellular divalent inorganic cation homeostasis. Among the most differentially expressed genes (DEGs) are CCL5/RANTES and CYP27B1, and several members of the metallothionein and metalloproteinase families. This is consistent with a proinflammatory state that would resemble macrophage rewiring toward granulomatous formation observed at the T-pole. Furthermore, a comparison with a dataset retrieved from the Gene Expression Omnibus of M. leprae-infected Schwann cells (MOI 100:1) showed that the patterns among the DEGs are highly distinct, as the Schwann cells under these conditions had a scavenging and phagocytic gene profile similar to M2-like macrophages, with enriched pathways rearrangements in the cytoskeleton, lipid and cholesterol metabolism and upregulated genes including MVK, MSMO1, and LACC1/FAMIN. In summary, macrophages may have a central role in defining the paradigmatic cellular (T-pole) vs. humoral (L-pole) responses and it is likely that the multiplicity of infection and genetic polymorphisms in key genes are gearing this polarization.

Atlantic Salmon Pre-smolt Survivors of Renibacterium salmoninarum Infection Show Inhibited Cell-Mediated Adaptive Immune Response and a Higher Risk of Death During the Late Stage of Infection at Lower Water Temperatures.

Bacterial kidney disease (BKD) is widespread in many areas of the world and can cause substantial economic losses for the salmon aquaculture industry. The objective of this study was to investigate the pathophysiological response and gene expression profiles related to the immune response at different water temperatures and to identify the best immunopathological biomarkers to define a phenotype of resistance to BKD. The abundance of msa transcripts of R. salmoninarum in the head kidney was significantly higher in infected fish at 11°C. R. salmoninarum induced significantly more severe kidney lesions, anemia and impaired renal function at 11°C. In addition, the expression pattern of the genes related to humoral and cell-mediated immune responses in infected fish at 11 and 15°C was very similar, although R. salmoninarum induced a significantly greater downregulation of the adaptive immune response genes at the lower water temperature. These results could be due to a suppressed host response directly related to the lowest water temperature and/or associated with a delayed host response related to the lowest water temperature. Although no significant differences in survival rate were observed, fish infected at the lowest temperature showed a higher probability of death and delayed the mortality curve during the late stage of infection (35 days after infection). Thirty-three immunopathological biomarkers were identified for potential use in the search for a resistance phenotype for BKD, and eight were genes related specifically to the adaptive cell-mediated immune response.

Vitamin A Impairs the Reprogramming of Tregs into IL-17-Producing Cells during Intestinal Inflammation.

Maintaining the identity of Foxp3(+) regulatory T cells (Tregs) is critical for controlling immune responses in the gut, where an imbalance between Tregs and T effector cells has been linked to inflammatory bowel disease. Accumulating evidence suggests that Tregs can convert into Th17 cells and acquire an inflammatory phenotype. In this study, we used an adoptive transfer model of Ag-specific T cells to study the contribution of different factors to the reprogramming of in vitro-generated Treg cells (iTreg) into IL-17-producing cells in a mouse model of gut inflammation in vivo. Our results show that intestinal inflammation induces the reprogramming of iTreg cells into IL-17-producing cells and that vitamin A restrains reprogramming in the gut. We also demonstrate that the presence of IL-2 during the in vitro generation of iTreg cells confers resistance to Th17 conversion but that IL-2 and retinoic acid (RA) cooperate to maintain Foxp3 expression following stimulation under Th17-polarizing conditions. Additionally, although IL-2 and RA differentially regulate the expression of different Treg cell suppressive markers, Treg cells generated under different polarizing conditions present similar suppressive capacity.

Factors associated with knowledge of the nursing staff at a teaching hospital on blood transfusion / Fatores associados ao conhecimento da equipe de enfermagem de um hospital de ensino sobre hemotransfusão / Factores asociados al conocimiento del equipo de enfermería sobre transfusión sanguínea en un hospital de enseñanza

AbstractObjective: to determine whether there is an association between knowledge of the nursing professionals about blood transfusion and the variables related to the professional aspects.Method: this is an observational, cross-sectional and quantitative study, carried out at a large general teaching hospital. The sample consisted of 209 nursing professionals, obtained by simple random sampling. For data collection, a checklist was used. In the univariate analysis, descriptive statistics and central trend and dispersion measures were used. In the bivariate analysis, Student's t-Test, analysis of variance and Pearson's correlation were used. To determine the predictors, multiple linear regression was applied. The Institutional Review Board (Opinion number 2434) approved the study.Results: the overall average knowledge score was 52.66%; in the Pre-transfusion Step, it corresponded to 53.38%; in the Transfusion Step 51.25% and, in the Post-transfusion Step, 62.68%. The factors related to knowledge were professional category and received training and/or guidance to accomplish the transfusion process (p<0.01).Conclusion: this study showed the influence of training and guidance on the knowledge and provided a diagnosis to identify the professionals' difficulties regarding the transfusion process.

ResumoObjetivo:verificar se há associação entre o conhecimento dos profissionais da equipe de enfermagem sobre hemotransfusão e as variáveis relacionadas aos aspectos profissionais.Método:trata-se de um estudo observacional, transversal, quantitativo, realizado em um hospital geral, de ensino e de grande porte. A amostra foi constituída por 209 profissionais da equipe de enfermagem, obtida por sorteio aleatório simples. A coleta de dados utilizou um instrumento do tipo checklist. Na análise univariada, utilizaram-se estatística descritiva e medidas de centralidade e de dispersão. Na análise bivariada, utilizaram-se o Teste t de Student, a análise de variância e a correlação de Pearson. Para determinar os preditores, utilizou-se a regressão linear múltipla. O estudo foi aprovado pelo Comitê de Ética em Pesquisa (Parecer n° 2434).Resultados:a média de escore geral de conhecimento foi de 52,66%, na Etapa Pré-transfusional foi de 53,38%; na Etapa Transfusional, 51,25%; e na Etapa Pós-transfusional, 62,68%. Os fatores relacionados ao conhecimento foram categoria profissional e receber treinamento e/ou orientação para a realização do processo transfusional (p<0,01).Conclusão:este estudo evidenciou a influência do treinamento e orientação sobre o conhecimento e forneceu um diagnóstico para a identificação das dificuldades dos profissionais relacionadas ao processo transfusional.

ResumenObjetivo:verificar si existe asociación entre el conocimiento de los profesionales del equipo de enfermería sobre transfusión sanguínea con las variables relacionadas a aspectos profesionales.Método:se trata de un estudio observacional, transversal, cuantitativo, realizado en un hospital general, de enseñanza y de gran porte. La muestra fue constituida por 209 profesionales del equipo de enfermería, obtenida por sorteo aleatorio simple. La recolección de datos utilizó un instrumento del tipo lista de verificación. En el análisis univariado, se utilizó la estadística descriptiva y las medidas de centralidad y de dispersión. En el análisis bivariado, se utilizaron el test t de Student, el análisis de variancia y la correlación de Pearson. Para determinar los factores de predicción, se utilizó la regresión linear múltiple. El estudio fue aprobado por el Comité de Ética en Investigación con dictamen n° 2434.Resultados:el promedio del puntaje general de conocimiento fue de 52,66%; en la Etapa de Pre-transfusión fue de 53,38%; en la Etapa de Transfusión, 51,25%; y, en la Etapa Post-transfusión, 62,68%. Los factores relacionados al conocimiento fueron: categoría profesional y recibir entrenamiento y/u orientación para la realización del proceso de transfusión (p<0,01).Conclusión:este estudio evidenció la influencia del entrenamiento y la orientación sobre el conocimiento y suministró un diagnóstico para la identificación de las dificultades de los profesionales relacionadas al proceso de transfusión.

The effects of reference genes in qRT-PCR assays for determining the immune response of bovine cells (MDBK) infected with the Bovine Viral Diarrhea Virus 1 (BVDV-1).

The bovine viral diarrhea virus (BVDV) causes significant economic losses to the dairy industry worldwide, and understanding its infection mechanisms would be extremely useful in designing new and efficient treatments. Due to the limited number of specific antibodies against bovine proteins, differential gene expression analyses are vital for researching host immune responses to viral infection. qRT-PCR provides a sensitive platform to conduct such gene expression analyses, but suitable housekeeping genes are needed for accurate transcript normalization. The present study assessed nine reference genes in bovine kidney cells under conditions of BVDV-1 infection, incubation with pathogen-associated molecular patterns, and co-incubation with BAY117085, a pharmacological inhibitor of the NF-κB signaling pathway. Analyses of Ct values using the BestKeeper and Normfinder programs ranked CD81, RPL4, and GAPDH as the most reliable reference genes. This determination of a stable set of reference genes in this culture system will facilitate analyses of expression levels for genes of interest.

Characterization of cross-protection by genetically modified live-attenuated Leishmania donovani parasites against Leishmania mexicana.

Previously, we showed that genetically modified live-attenuated Leishmania donovani parasite cell lines (LdCen(-/-) and Ldp27(-/-)) induce a strong cellular immunity and provide protection against visceral leishmaniasis in mice. In this study, we explored the mechanism of cross-protection against cutaneous lesion-causing Leishmania mexicana. Upon challenge with wild-type L. mexicana, mice immunized either for short or long periods showed significant protection. Immunohistochemical analysis of ears from immunized/challenged mice exhibited significant influx of macrophages, as well as cells expressing MHC class II and inducible NO synthase, suggesting an induction of potent host-protective proinflammatory responses. In contrast, substantial inhibition of IL-10, IL-4, and IL-13 expression and the absence of degranulated mast cells and less influx of eosinophils within the ears of immunized/challenged mice suggested a controlled anti-inflammatory response. L. mexicana Ag-stimulated lymph node cell culture from the immunized/challenged mice revealed induction of IFN-γ secretion by the CD4 and CD8 T cells compared with non-immunized/challenged mice. We also observed suppression of Th2 cytokines in the culture supernatants of immunized/challenged lymph nodes compared with non-immunized/challenged mice. Adoptively transferred total T cells from immunized mice conferred strong protection in recipient mice against L. mexicana infection, suggesting that attenuated L. donovani can provide protection against heterologous L. mexicana parasites by induction of a strong T cell response. Furthermore, bone marrow-derived dendritic cells infected with LdCen(-/-) and Ldp27(-/-) parasites were capable of inducing a strong proinflammatory response leading to the proliferation of Th1 cells. These studies demonstrate the potential of live-attenuated L. donovani parasites as pan-Leishmania species vaccines.

Moving receptor redirected adoptive cell therapy toward fine tuning of antitumor responses.

Adoptive cell transfer (ACT) is emerging as a powerful modality of cancer treatment. While ACT has proved able to induce massive clinical responses, genetic modification of T lymphocytes further improved clinical responses obtained. One of the major current limitations of ACT is the inability to discern healthy from malignant cells, leading to on target/off tumor responses that can limit its application. We here discuss some of the approaches currently under development and potential solutions to circumvent these limitations and extend this potentially curative therapy to different tumors by targeting a variety of antigens.

Modulation of T-cell mediated immunity by dopamine receptor d5.

CD4+ T-cells are central players orchestrating antigen-specific immunity and tolerance. Importantly, dendritic cells (DCs) are responsible for priming T-cells and for promoting their differentiation from naïve T-cells into appropriate functional cells. Because of their fundamental roles in controlling immunity, activation and differentiation of DCs and CD4+ T-cells require tight regulatory mechanisms. Several studies have shown that dopamine, not only mediates interactions into the nervous system, but it can also contribute to the modulation of immunity. Here, we review the emerging role of this neurotransmitter as a regulator of DCs and CD4+ T-cells physiology and its consequent involvement, in the regulation of immune response. We specially focus the analysis in the role of dopamine receptor D5 expressed on DCs and CD4+ T-cells in the modulation of immunity. We also discuss how alterations in the dopamine-mediated regulation of immunity could contribute to the onset and development of immune-related disorders.

Bacterial sensing, cell signaling, and modulation of the immune response during sepsis.

Since the definition of systemic inflammatory response syndrome/sepsis was originally proposed, a large amount of new information has been generated showing a much more complex scenario of inflammatory and counterinflammatory responses during sepsis. Moreover, some fundamental mechanisms of sensing and destroying invading microorganisms have been uncovered, which include the discovery of TLR4 as the lipopolysaccharide (LPS) gene, implications of innate immune cells as drivers of the adaptive response to infection, and the modulation of multiple accessory molecules that stimulate or inhibit monocyte/macrophage and lymphocyte interactions. The complexity of the infection/injury-induced immune response could be better appreciated with the application of genomics and proteomics studies, and LPS was a useful tool in many of these studies. In this review, we discuss aspects of bacterial recognition and induced cellular activation during sepsis. Because of the relevance of endotoxin (LPS) research in the field, we focus on LPS and host interactions as a clue to understand microorganisms sensing and cell signaling, then we discuss how this response is modulated in septic patients.

Understanding rheumatic fever.

Through a comprehensive review of the recent findings on rheumatic fever, we intend to propose a new physiopathologic model for this disease. A Medline search was performed for all articles containing the terms rheumatic fever or rheumatic heart disease in title or abstract from 1970 to 2011. Best evidence qualitative technique was used to select the most relevant. The scientific interest on rheumatic fever has notably diminished throughout the twentieth century as evidenced by the comparison of the proportion of articles in which RF was a subject in 1950 (0.26%) and today (0.03%) [Pubmed]. However, RF remains a major medical and social problem in the developing world and in the so-called hotspots, where it still causes around 500.000 deaths each year, not too different from the pre-antibiotic era. The role of genetic factors in RF susceptibility is discussed. Familiar aggregation, similarity of disease patterns between siblings, identical twin, and HLA correlation studies are evidence for a genetic influence on RF susceptibility. The suspect-involved genes fall mainly into those capable of immunologic mediation. Molecular mimicry explains the triggering of RF, but an intense and sustained inflammation is needed to cause sequels. Also, RF patients vary greatly in terms of symptoms. It is likely that a genetic background directing immune response towards a predominantly Th1 or Th2 pattern contributes to these features. The recent findings on rheumatic fever provide important insight on its physiopathology that helps understanding this prototype post-infectious autoimmune disease giving insights on other autoimmune conditions.

Proteínas séricas de potros da raça Puro Sangue Árabe recém-desmamados ou com mais de trinta dias de desmame / Serum protein profile in Arabian foals recently weaned or at more than thirty days after weaning

A fase perinatal do desenvolvimento constitui um dos períodos de vida mais desafiadores para o sistema imunológico dos potros. O objetivo do presente estudo foi verificar o perfil protéico sérico de parâmetros relacionados à imunidade de equinos jovens no período perinatal, verificando-se a transferência de imunidade passiva. Oito animais desmamados há um dia, formaram o Grupo 1 (G1), enquanto vinte animais desmamados há mais de trinta dias formaram o Grupo 2 (G2). A concentração sérica de proteína total foi determinada por refratometria. Para o fracionamento das proteínas, utilizou-se eletroforese em gel de acrilamida. Os resultados obtidos foram submetidos à análise de medidas repetidas e ao teste Tukey (p<0,05) para comparação das médias. As concentrações de IgA apresentaram diferença (p<0,05) entre os grupos, porém os valores observados encontravam-se dentro do considerado normal para equinos adultos. Não houve diferença (p>0,05) nas concentrações de IgG. O estabelecimento adequado da imunidade celular ocorre durante a fase neonatal, nos animais que ingerem adequadamente o colostro e o leite. O presente estudo determinou diferenças no perfil protéico sérico de parâmetros relacionados à imunidade de equinos jovens no período imediato ao desmame, comparados com animais desmamados há mais de 30 dias. De acordo com os valores observados, concluiu-se que os animais, mesmo desmamados precocemente, obtiveram transferência adequada de imunidade passiva.

The perinatal phase of foal development is one of the most challenger period for the immune system. The present study has analyzed serum protein profile, considering variables related to immunity in foals at the perinatal phase, verifying passive immunity transfer. The group 1 (G1) contained eight foals evaluated one day after weaning, and group 2 (G2) included twenty foals at more than thirty days after weaning. Total protein concentration was determined by means of refractometry. The concentration of serum proteins was determined through sodium dodecyl sulphatepolyacrylamide gel electrophoresis. Results were submitted to analysis of variance and Tukey test (P<0.05). IgA concentration showed difference (P<0.05) between the two studied groups, however data were within adult healthy horses normal values. IgG didn't show statistical difference (P>0.05). The cellular immunity establishment occurs in the neonatal phase, in foals that suckled colostrum and milk properly. The present study showed differences in serum protein profile, considering variables related to immunity, in foals immediately after weaning comparing to foals at more than 30 days after weaning. According to the observed values, we conclude that foals, even early weaned, showed proper passive immunity tranfer.

Proteínas séricas de potros da raça Puro Sangue Árabe recém-desmamados ou com mais de trinta dias de desmame / Serum protein profile in Arabian foals recently weaned or at more than thirty days after weaning

A fase perinatal do desenvolvimento constitui um dos períodos de vida mais desafiadores para o sistema imunológico dos potros. O objetivo do presente estudo foi verificar o perfil protéico sérico de parâmetros relacionados à imunidade de equinos jovens no período perinatal, verificando-se a transferência de imunidade passiva. Oito animais desmamados há um dia, formaram o Grupo 1 (G1), enquanto vinte animais desmamados há mais de trinta dias formaram o Grupo 2 (G2). A concentração sérica de proteína total foi determinada por refratometria. Para o fracionamento das proteínas, utilizou-se eletroforese em gel de acrilamida. Os resultados obtidos foram submetidos à análise de medidas repetidas e ao teste Tukey (p<0,05) para comparação das médias. As concentrações de IgA apresentaram diferença (p<0,05) entre os grupos, porém os valores observados encontravam-se dentro do considerado normal para equinos adultos. Não houve diferença (p>0,05) nas concentrações de IgG. O estabelecimento adequado da imunidade celular ocorre durante a fase neonatal, nos animais que ingerem adequadamente o colostro e o leite. O presente estudo determinou diferenças no perfil protéico sérico de parâmetros relacionados à imunidade de equinos jovens no período imediato ao desmame, comparados com animais desmamados há mais de 30 dias. De acordo com os valores observados, concluiu-se que os animais, mesmo desmamados precocemente, obtiveram transferência adequada de imunidade passiva.(AU)

The perinatal phase of foal development is one of the most challenger period for the immune system. The present study has analyzed serum protein profile, considering variables related to immunity in foals at the perinatal phase, verifying passive immunity transfer. The group 1 (G1) contained eight foals evaluated one day after weaning, and group 2 (G2) included twenty foals at more than thirty days after weaning. Total protein concentration was determined by means of refractometry. The concentration of serum proteins was determined through sodium dodecyl sulphatepolyacrylamide gel electrophoresis. Results were submitted to analysis of variance and Tukey test (P<0.05). IgA concentration showed difference (P<0.05) between the two studied groups, however data were within adult healthy horses normal values. IgG didn't show statistical difference (P>0.05). The cellular immunity establishment occurs in the neonatal phase, in foals that suckled colostrum and milk properly. The present study showed differences in serum protein profile, considering variables related to immunity, in foals immediately after weaning comparing to foals at more than 30 days after weaning. According to the observed values, we conclude that foals, even early weaned, showed proper passive immunity tranfer.(AU)

Host genetic background affects regulatory T-cell activity that influences the magnitude of cellular immune response against Mycobacterium tuberculosis.

Using two mouse strains with different abilities to generate interferon (IFN)-γ production after Mycobacterium tuberculosis infection, we tested the hypothesis that the frequency and activity of regulatory T (Treg) cells are influenced by genetic background. Our results demonstrated that the suppressive activity of spleen Treg cells from infected or uninfected BALB/c mice was enhanced, inhibiting IFN-γ and interleukin (IL)-2 production. Infected C57BL/6 mice exhibited a decrease in the frequency of lung Treg cells and an increased ratio CD4(+):CD4(+)Foxp3(+) cells compared with infected BALB/c mice and uninfected C57BL/6 mice. Moreover, infected C57BL/6 mice also had a decrease in the immunosuppressive capacity of spleen Treg cells, higher lung IFN-γ and IL-17 production, and restricted the infection better than BALB/c mice. Adoptive transfer of BALB/c Treg cells into BALB/c mice induced an increase in bacterial colony-forming unit (CFU) counts. Furthermore, BALB/c mice treated with anti-CD25 antibody exhibited lung CFU counts significantly lower than mice treated with irrelevant antibody. Our results show that in BALB/c mice, the Treg cells have a stronger influence than that in C57BL/6 mice. These data suggest that BALB/c and C57BL/6 mice may use some different mechanisms to control M. tuberculosis infection. Therefore, the role of Treg cells should be explored during the development of immune modulators, both from the perspective of the pathogen and the host.

Unexpected diversity of cellular immune responses against Nef and Vif in HIV-1-infected patients who spontaneously control viral replication.

BACKGROUND: HIV-1-infected individuals who spontaneously control viral replication represent an example of successful containment of the AIDS virus. Understanding the anti-viral immune responses in these individuals may help in vaccine design. However, immune responses against HIV-1 are normally analyzed using HIV-1 consensus B 15-mers that overlap by 11 amino acids. Unfortunately, this method may underestimate the real breadth of the cellular immune responses against the autologous sequence of the infecting virus. METHODOLOGY AND PRINCIPAL FINDINGS: Here we compared cellular immune responses against nef and vif-encoded consensus B 15-mer peptides to responses against HLA class I-predicted minimal optimal epitopes from consensus B and autologous sequences in six patients who have controlled HIV-1 replication. Interestingly, our analysis revealed that three of our patients had broader cellular immune responses against HLA class I-predicted minimal optimal epitopes from either autologous viruses or from the HIV-1 consensus B sequence, when compared to responses against the 15-mer HIV-1 type B consensus peptides. CONCLUSION AND SIGNIFICANCE: This suggests that the cellular immune responses against HIV-1 in controller patients may be broader than we had previously anticipated.

Leprosy: diagnostic and control challenges for a worldwide disease.

Leprosy is a curable disease with well-defined etiology, but lacks better diagnostic tools, preventive and therapeutic strategies. The continued application of the Ridley-Jopling clinical classification that recognizes the natural diversity of the immune response has provided the basis for understanding leprosy, and this review proposes its implementation in all Reference Centers in order to standardize the diagnostic resources, aiming at the improvement of the disease control. Due to the broad bioepidemiological aspects of infection its eradication is difficult, and proper diagnosis of the disease and the correct clinical classification are required to ensure proper treatment. Tools and markers for diagnosis and prognosis, and the novel use of nanotechnology, as well as strategies for disease control and monitoring populations at higher risk are still continuous challenges, which will be specifically reviewed with additional insights. The use of the current diagnostic tools, such as ELISA and PCR has a very limited approach for leprosy that has been considered as a marginal disease; therefore, the current diagnostic tools must be applied extensively in the routine to accumulate clinical experience in order to improve their precise application, like what has been done in many other infectious diseases. Since a vaccine for leprosy presents an unpredictable future, the proposed chemoprophylaxis of contacts (healthy carriers and/or with subclinical infection) must also be employed in referral centers of endemic countries not only to evaluate its efficacy, but also because of the favorable cost-benefit ratio, given that there is no other available approach, besides the multi-drug therapy of patients. This strategy should readily be applied as a public health policy, and may lead to a substantial breakage of the transmission chain aiming a world without leprosy.

CCR5-dependent regulatory T cell migration mediates fungal survival and severe immunosuppression.

Paracoccidioidomycosis, a debilitating pulmonary mycosis, is caused by the dimorphic fungus Paracoccidioides brasiliensis. The infection results in the formation of granulomas containing viable yeast cells that are the fungal sources for disease reactivation. Because CD4+CD25+ regulatory T cells (Tregs) are in the lesions of patients with paracoccidioidomycosis, the migration of Treg cells is dependent on the axis chemokine-chemokine receptors, and CCR5 ligands are produced in P. brasiliensis-induced lesions, we investigated the role of CCR5 in the control of the infection. The results showed that CCR5-/- mice are more efficient in controlling fungal growth and dissemination and exhibited smaller granulomas than wild-type (WT) mice. In the absence of CCR5, the percentage of CD4+CD25+ T cells expressing Foxp3, glucocorticoid-induced TNFR (GITR), CD103, CD45low, and CTLA-4 in the granulomas was significantly decreased. Interestingly, P. brasiliensis infection resulted in an absence of T cell proliferation in response to Con A in WT but not CCR5-/- mice that was abrogated by anti-CTLA-4 mAb and anti-GITR mAb. Moreover, the adoptive transfer of CD4+CD25+ but not CD4+CD25- T cells from infected WT to infected CCR5-/- mice resulted in a significant increase in fungal load. Overall, CCR5 is a key receptor for the migration of Treg cells to the site of P. brasiliensis infection, leading to down-modulation of effector immune response and the long-term presence of the fungus in the granulomas. Thus, a tight control of Treg cell migration to the granulomatous lesions could be an important mechanism for avoiding exacerbation and reactivation of the disease.