Introduction: Innate immune training is a metabolic, functional, and epigenetic long-term reprogr... more Introduction: Innate immune training is a metabolic, functional, and epigenetic long-term reprogramming of innate cells triggered by different stimuli. This imprinting also reaches hematopoietic precursors in the bone marrow to sustain a memory-like phenotype. Dendritic cells (DCs) can exhibit memory-like responses, enhanced upon subsequent exposure to a pathogen; however, whether this imprinting is lineage and stimulus-restricted is still being determined. Nevertheless, the functional consequences of DCs training on the adaptive and protective immune response against non-infectious diseases remain unresolved. Methods: We evaluated the effect of the nontoxic cholera B subunit (CTB), LPS and LTA in the induction of trained immunity in murine DCs revealed by TNFa and LDH expression, through confocal microscopy. Additionally, we obtained bone marrow DCs (BMDCs) from mice treated with CTB, LPS, and LTA and evaluated training features in DCs and their antigen-presenting cell capability using multiparametric cytometry. Finally, we design an experimental melanoma mouse model to demonstrate protection induced by CTB-trained DCs in vivo. Results: CTB-trained DCs exhibit increased expression of TNFa, and metabolic reprogramming indicated by LDH expression. Moreover, CTB training has an imprint on DC precursors, increasing the number and antigen-presenting function in BMDCs. We found that training by CTB stimulates the recruitment of DC precursors and DCs infiltration at the skin and lymph nodes. Interestingly, training-induced by CTB promotes a highly co-stimulatory phenotype in tumorinfiltrating DCs (CD86+) and a heightened functionality of exhausted CD8 T cells (Ki67+, GZMB+), which were associated with a protective response against melanoma challenge in vivo.
Salmonella enterica serovar Typhi (S. Typhi) porins, OmpC and OmpF, are potent inducers of the im... more Salmonella enterica serovar Typhi (S. Typhi) porins, OmpC and OmpF, are potent inducers of the immune response against S. Typhi in mice and humans. Vaccination with porins induces the protection against 500 LD50 of S. Typhi, life-lasting bactericidal antibodies and effector T cell responses in mice; however, the nature of the memory T cell compartment and its contribution to protection remains unknown. In this work, we firstly observed that vaccination with porins induces in situ (skin) CD4+ and CD8+ T cell responses. Analysis of the porin-specific functional responses of skin CD4+ and CD8+ T cells showed IFN-gamma- and IL-17-producing cells in both T cell populations. The memory phenotype of porin-specific T cells indicated the presence of resident and effector memory phenotypes in the skin, and a central memory phenotype in the skin-draining lymph node. In addition, we demonstrated that vaccination with porins via skin reduces the bacterial burden following challenge. Finally, eva...
Dendritic cell (DC) targeting by DEC205+ cells effectively promotes the internalization of antige... more Dendritic cell (DC) targeting by DEC205+ cells effectively promotes the internalization of antigens that may trigger a specific immune response. In this study, we evaluated the ability of a recombinant antibody, anti-DEC205 (rAb ZH9F7), to trigger cellular endocytosis in subpopulations of DCs and targeted cells after intradermal injection and subsequent migration toward lymph nodes. Furthermore, the cellular immune response was evaluated in pigs after intradermal application of the antigenized rAb ZH9F7 combined with porcine circovirus type 2 cap antigen (rAb ZH9F7-Cap). We demonstrated that rAb ZH9F7 recognized conventional type 1 and 2 DCs from the blood and skin and monocytes. It promoted receptor-mediated endocytosis and migration of cDCs and moDCs toward regional lymph nodes. Intradermal application of rAb ZH9F7-Cap induced a higher frequency of IFN-γ-secreting CD4+CD8+ T lymphocytes and antibodies against Cap protein than that in the control group. In conclusion, the rAb ZH9F7...
In cutaneous T cell lymphoma (CTCL), a dominant Th2 profile associated with disease progression h... more In cutaneous T cell lymphoma (CTCL), a dominant Th2 profile associated with disease progression has been proposed. Moreover, although the production and regulation of IL-4 expression during the early stages of the disease may have important implications in later stages, these processes are poorly understood. Here, we demonstrate the presence of TOX+ CD4+ T cells that produce IL-4+ in early-stage skin lesions of CTCL patients and reveal a complex mechanism by which the NLRP3 receptor promotes a Th2 response by controlling IL-4 production. Unassembled NLRP3 is able to translocate to the nucleus of malignant CD4+ T cells, where it binds to the human il-4 promoter. Accordingly, IL-4 expression is decreased by knocking down and increased by promoting the nuclear localization of NLRP3. We describe a positive feedback loop in which IL-4 inhibits NLRP3 inflammasome assembly, thereby further increasing its production. IL-4 induced a potentially malignant phenotype measured based on TOX expre...
Psoriasis is a chronic inflammatory disease distinguished by an excessive proliferation and abnor... more Psoriasis is a chronic inflammatory disease distinguished by an excessive proliferation and abnormal differentiation of keratinocytes. Immune cells, such as T lymphocytes and neutrophils, and inflammatory cytokines, such as Tumor Necrosis Factor-α (TNF-α) and interleukin 17 (IL-17), are essential for maintaining psoriatic lesions. Additionally, a hypoxic milieu present in the skin promotes the expression of transcriptional factor hypoxia-inducible factor-1 alpha (HIF-1α). This protein regulates the expression of angiogenic and glycolytic factors, such as vascular endothelial grown factor and lactate dehydrogenase (LDH), both relevant in chronic inflammation. The von Hippel–Lindau protein (pVHL) is a negative regulator of HIF-1α. Previously, we found that pVHL was almost absent in the lesions of psoriasis patients; therefore, we investigated the impact of rescue pVHL expression in lesional skin. We used the imiquimod-induced psoriasis-like mouse model as an adenoviral vector that all...
PD-L1 expression plays a critical role in the impairment of T cell responses during chronic infec... more PD-L1 expression plays a critical role in the impairment of T cell responses during chronic infections; however, the expression of PD-L1 on T cells during acute viral infections, particularly during the pandemic influenza virus (A(H1N1)pdm09), and its effects on the T cell response have not been widely explored. We found that A(H1N1)pdm09 virus induced PD-L1 expression on human dendritic cells (DCs) and T cells, as well as PD-1 expression on T cells. PD-L1 expression impaired the T cell response against A(H1N1)pdm09 by promoting CD8+T cell death and reducing cytokine production. Furthermore, we found increased PD-L1 expression on DCs and T cells from influenza-infected patients from the first and second 2009 pandemic waves in Mexico City. PD-L1 expression on CD8+T cells correlated inversely with T cell proportions in patients infected with A(H1N1)pdm09. Therefore, PD-L1 expression on DCs and T cells could be associated with an impaired T cell response during acute infection with A(H...
The relationship between the neuroendocrine and the immune systems is essential to maintain homeo... more The relationship between the neuroendocrine and the immune systems is essential to maintain homeostasis. Their complex interactions are present in many physiological or pathological states whereby hormones exert different actions in immune system cells and vice versa. Hormones such as prolactin, growth hormone, cortisol and sex hormones are known to regulate the differentiation and function of immune system cells and the production of cytokines. Many of these cells express hormone receptors leading to the tempering of several autoimmune and neoplastic diseases. The pituitary gland is susceptible to autoimmune damage, be it because of primary lymphocytic hypophysitis, as part of IgG4-related disease or as an adverse event of treatment with immune checkpoint inhibitors (ICi). Finally, pituitary adenomas, like many other neoplasms, are frequently infiltrated by different cells of the immune system, a phenomenon that can be related to the degree of invasiveness of these lesions. The purpose of the present work is to critically analyze the neuroendocrine-immune interphase, from both a biological and a clinical perspective.
Revista médica del Instituto Mexicano del Seguro Social, 2012
Ralph M. Steinman fue galardonado con el Premio Nobel de Fisiologia y Medicina 2011 por su descub... more Ralph M. Steinman fue galardonado con el Premio Nobel de Fisiologia y Medicina 2011 por su descubrimiento de las celulas dendriticas, fundamentales en la induccion de respuestas inmunologicas adquiridas necesarias para la defensa del organismo. Actualmente las celulas dendriticas se han aprovechado para el desarrollo de vacunas y terapia oncologica
Nontuberculous mycobacteria (NTM) are recognized as emerging pathogens and their immune regulator... more Nontuberculous mycobacteria (NTM) are recognized as emerging pathogens and their immune regulatory mechanisms are not well described yet. From them, Mycobacterium avium is known to be a weak activator of dendritic cells (DCs) that impairs the response induced by BCG vaccine. However, whether other NTM such as Mycobacterium scrofulaceum may modulate the activation of DCs, has not been extensively studied. Here, we exposed bone marrow-derived DCs (BMDCs) to M. scrofulaceum and we analyzed the effect on the activation of DCs. We found that M. scrofulaceum has a comparable ability to induce a semi-mature DC phenotype, which was produced by its interaction with DC-SIGN and TLR4 receptors in a synergic effect. BMDCs exposed to M. scrofulaceum showed high expression of PD-L2 and production of IL-10, as well as low levels of co-stimulatory molecules and pro-inflammatory cytokines. In addition to immunophenotype induced on DCs, changes in morphology, re-organization of cytoskeleton and decreased migratory capacity are consistent with a semi-mature phenotype. However, unlike other pathogenic mycobacteria, the DC-semi-mature phenotype induced by M. scrofulaceum was reversed after re-exposure to BCG, suggesting that modulation mechanisms of DC-activation used by M. scrofulaceum are different to other known pathogenic mycobacteria. This is the first report about the immunophenotypic characterization of DC stimulated by M. scrofulaceum.
Psoriasis is an inflammatory autoimmune disease characterized by cutaneous lesions in plaques. It... more Psoriasis is an inflammatory autoimmune disease characterized by cutaneous lesions in plaques. It has been proposed that the immune response has a key role in the disease progression. Particularly, the Th17 cells through IL-17 can contribute to maintain the inflammatory process. The pathogenic Th17 phenotype has been described in human diseases and associated with high severity in inflammatory experimental models. However, it is not clear if the pathogenic phenotype could be present in the skin and peripheral blood as well as its possible association to severity in psoriasis. In the lesional skin, we found high infiltration of Th17 cells and the pathogenic phenotype, finding a correlation between the frequency of Th17 cells and the Psoriasis Area and Severity Index (PASI) score. In peripheral blood, we observed a pool of Th17 lymphocytes with potential to acquire pathogenic features. Interestingly, the percentage of pathogenic Th17 cells (CD4+ RORγt+ IFN-γ+) correlates with disease ...
SARS-CoV-2, the etiological agent causing COVID-19, has infected more than 8.7 million people wit... more SARS-CoV-2, the etiological agent causing COVID-19, has infected more than 8.7 million people with over 461000 deaths worldwide since its emergence in December 2019. Factors for severe disease, such as diabetes, hypertension and obesity have been identified however, the precise pathogenesis is poorly understood. In order to understand its pathophysiology and to develop effective therapeutic strategies, it is essential to define the prevailing immune cellular subsets. We performed circulating immune cells scRNAseq from five critically ill COVID-19 patients. Immature myeloid populations, such as promyelocytes-myelocytes, metamyelocytes, band neutrophils, monocytoid precursors and activated monocytes predominated. Trajectory with pseudotime analysis supported the finding of immature cell states. Gene ontology showed myeloid cell activation in immune response, DNA and RNA processing, defense response to virus and response to type 1 interferon. Lymphoid lineage was scarce. Our results un...
CD4 T cells are major players in the immune response against several diseases; including AIDS, le... more CD4 T cells are major players in the immune response against several diseases; including AIDS, leishmaniasis, tuberculosis, influenza and cancer. Their activation has been successfully achieved by administering antigen coupled with antibodies, against DC-specific receptors in combination with adjuvants. Unfortunately, most of the adjuvants used so far in experimental models are unsuitable for human use. Therefore, human DC-targeted vaccination awaits the description of potent, yet nontoxic adjuvants. The nontoxic cholera B subunit (CTB) can be safely used in humans and it has the potential to activate CD4 T cell responses. However, it remains unclear whether CTB can promote DC activation and can act as an adjuvant for DC-targeted antigens. Here, we evaluated the CTB's capacity to activate DCs and CD4 T cell responses, and to generate long-lasting protective immunity. Intradermal (i.d.) administration of CTB promoted late and prolonged activation and accumulation of skin and lymp...
Sporotrichosis is a chronic subcutaneous mycosis caused by the species complex and it is consider... more Sporotrichosis is a chronic subcutaneous mycosis caused by the species complex and it is considered an emerging opportunistic infection in countries with tropical and subtropical climates. The host's immune response has a main role in the development of this disease. However, it is unknown the features of the memory cellular immune response that could protect against the infection. Our results show that i.d. immunization in the ears of mice with inactivated conidia (iC) combined with the cholera toxin (CT) induces a cellular immune response mediated by circulating memory CD4 T cells, which mainly produce interleukin 17 (IL-17). These cells mediate a strong delayed-type hypersensitivity (DTH) reaction. Systemic and local protection against was mediated by circulating CD4 T cells. In contrast, the infection induces a potent immune response in the skin mediated by CD4 T cells, which have an effector phenotype that preferentially produce interferon gamma (IFN-γ) and mediate a transi...
Antigen processing for presentation by major histocompatibility complex class II (MHCII) molecule... more Antigen processing for presentation by major histocompatibility complex class II (MHCII) molecules requires the latter to travel through the endocytic pathway together with its chaperons: the invariant chain (Ii) and DM. Nevertheless, the nature of the compartments where MHCII molecules travel to acquire peptides lacks definition regarding molecules involved in intracellular vesicular trafficking, such as Rab small GTPases. We aimed to define which Rab proteins are present during the intracellular transport of MHCII, DM, and Ii through the endocytic pathway on their route to the cell surface during dendritic cell (DC) maturation. We examined, by means of three-color confocal microscopy, the association of MHCII, DM, and Ii with Rab5, Rab7, Rab9, and Rab11 during the maturation of bone marrow-derived or spleen DC in response to LPS as an inflammatory stimulus. Prior to the stage of immature DC, MHCII migrated from diffuse small cytoplasmic vesicles, predominantly Rab5+Rab7- and Rab5+...
Inhibins are members of the TGFβ superfamily, which regulate many cellular processes including di... more Inhibins are members of the TGFβ superfamily, which regulate many cellular processes including differentiation, proliferation, survival and apoptosis. Although initially described as hormones regulating the hypothalamus-pituitary-gonadal axis, based on their ability to antagonize Activins, our group has recently reported that they play a role in thymocyte differentiation and survival, as well as in thymic stromal cell maturation and nTreg generation. Here, we used Inhibin knock out mice (Inhα-/-) to investigate the role of Inhibins in peripheral dendritic cell maturation and function. We first demonstrated that LPS treated Inhα+/+ bone marrow derived dendritic cells (BMDC) were capable to produce significant levels of Inhibin A. Interestingly, Inhα-/- BMDC showed reduced MHCII and CD86 upregulation and increased PD-L1 expression in response to LPS compared to Inhα+/+, which correlated with reduced ability to induce proliferation of allogeneic T cells. The "semi-mature" phe...
Innate lymphoid cells (ILC) are members of a heterogeneous family with a lymphoid origin that mim... more Innate lymphoid cells (ILC) are members of a heterogeneous family with a lymphoid origin that mimics the T helper (Th) cytokine profile. ILC are involved in early effector cytokine-mediated responses during infections in peripheral tissues. ILC also play an important role in chronic skin inflammatory diseases, including psoriasis. Although classical ILC express CD127, it has been recently reported that the presence of non-classical CD127(-) ILC populations and an early ILC precursor (EILP) CD127(low). ILC development has predominately been investigated in mouse models. However, in humans, different transcription factors have been described for ILC identification. NFIL3 (nuclear factor, IL-3 regulated) is crucial for ILC development in response to IL-7. CD123 (IL-3Rα) is usually used to exclude basophils during ILC identification, however, it is unknown if in response to IL-3, NFIL3 could be relevant to induce ILC features in Lin(-) CD123(+) populations in addition, is also unknown w...
Revista Medica Del Instituto Mexicano Del Seguro Social, Mar 1, 2012
Ralph M. Steinman was the recipient of the 2011 Nobel Prize of Physiology and Medicine due to the... more Ralph M. Steinman was the recipient of the 2011 Nobel Prize of Physiology and Medicine due to the discovery of dendritic cells, which have a crucial role on the onset of acquired immunity, a fundamental event in the organism's defense. Today, dendritic cells are used in the development of vaccines and in cancer therapy. Steinman's contributions have been fundamental in the understanding of immunity.
Introduction: Innate immune training is a metabolic, functional, and epigenetic long-term reprogr... more Introduction: Innate immune training is a metabolic, functional, and epigenetic long-term reprogramming of innate cells triggered by different stimuli. This imprinting also reaches hematopoietic precursors in the bone marrow to sustain a memory-like phenotype. Dendritic cells (DCs) can exhibit memory-like responses, enhanced upon subsequent exposure to a pathogen; however, whether this imprinting is lineage and stimulus-restricted is still being determined. Nevertheless, the functional consequences of DCs training on the adaptive and protective immune response against non-infectious diseases remain unresolved. Methods: We evaluated the effect of the nontoxic cholera B subunit (CTB), LPS and LTA in the induction of trained immunity in murine DCs revealed by TNFa and LDH expression, through confocal microscopy. Additionally, we obtained bone marrow DCs (BMDCs) from mice treated with CTB, LPS, and LTA and evaluated training features in DCs and their antigen-presenting cell capability using multiparametric cytometry. Finally, we design an experimental melanoma mouse model to demonstrate protection induced by CTB-trained DCs in vivo. Results: CTB-trained DCs exhibit increased expression of TNFa, and metabolic reprogramming indicated by LDH expression. Moreover, CTB training has an imprint on DC precursors, increasing the number and antigen-presenting function in BMDCs. We found that training by CTB stimulates the recruitment of DC precursors and DCs infiltration at the skin and lymph nodes. Interestingly, training-induced by CTB promotes a highly co-stimulatory phenotype in tumorinfiltrating DCs (CD86+) and a heightened functionality of exhausted CD8 T cells (Ki67+, GZMB+), which were associated with a protective response against melanoma challenge in vivo.
Salmonella enterica serovar Typhi (S. Typhi) porins, OmpC and OmpF, are potent inducers of the im... more Salmonella enterica serovar Typhi (S. Typhi) porins, OmpC and OmpF, are potent inducers of the immune response against S. Typhi in mice and humans. Vaccination with porins induces the protection against 500 LD50 of S. Typhi, life-lasting bactericidal antibodies and effector T cell responses in mice; however, the nature of the memory T cell compartment and its contribution to protection remains unknown. In this work, we firstly observed that vaccination with porins induces in situ (skin) CD4+ and CD8+ T cell responses. Analysis of the porin-specific functional responses of skin CD4+ and CD8+ T cells showed IFN-gamma- and IL-17-producing cells in both T cell populations. The memory phenotype of porin-specific T cells indicated the presence of resident and effector memory phenotypes in the skin, and a central memory phenotype in the skin-draining lymph node. In addition, we demonstrated that vaccination with porins via skin reduces the bacterial burden following challenge. Finally, eva...
Dendritic cell (DC) targeting by DEC205+ cells effectively promotes the internalization of antige... more Dendritic cell (DC) targeting by DEC205+ cells effectively promotes the internalization of antigens that may trigger a specific immune response. In this study, we evaluated the ability of a recombinant antibody, anti-DEC205 (rAb ZH9F7), to trigger cellular endocytosis in subpopulations of DCs and targeted cells after intradermal injection and subsequent migration toward lymph nodes. Furthermore, the cellular immune response was evaluated in pigs after intradermal application of the antigenized rAb ZH9F7 combined with porcine circovirus type 2 cap antigen (rAb ZH9F7-Cap). We demonstrated that rAb ZH9F7 recognized conventional type 1 and 2 DCs from the blood and skin and monocytes. It promoted receptor-mediated endocytosis and migration of cDCs and moDCs toward regional lymph nodes. Intradermal application of rAb ZH9F7-Cap induced a higher frequency of IFN-γ-secreting CD4+CD8+ T lymphocytes and antibodies against Cap protein than that in the control group. In conclusion, the rAb ZH9F7...
In cutaneous T cell lymphoma (CTCL), a dominant Th2 profile associated with disease progression h... more In cutaneous T cell lymphoma (CTCL), a dominant Th2 profile associated with disease progression has been proposed. Moreover, although the production and regulation of IL-4 expression during the early stages of the disease may have important implications in later stages, these processes are poorly understood. Here, we demonstrate the presence of TOX+ CD4+ T cells that produce IL-4+ in early-stage skin lesions of CTCL patients and reveal a complex mechanism by which the NLRP3 receptor promotes a Th2 response by controlling IL-4 production. Unassembled NLRP3 is able to translocate to the nucleus of malignant CD4+ T cells, where it binds to the human il-4 promoter. Accordingly, IL-4 expression is decreased by knocking down and increased by promoting the nuclear localization of NLRP3. We describe a positive feedback loop in which IL-4 inhibits NLRP3 inflammasome assembly, thereby further increasing its production. IL-4 induced a potentially malignant phenotype measured based on TOX expre...
Psoriasis is a chronic inflammatory disease distinguished by an excessive proliferation and abnor... more Psoriasis is a chronic inflammatory disease distinguished by an excessive proliferation and abnormal differentiation of keratinocytes. Immune cells, such as T lymphocytes and neutrophils, and inflammatory cytokines, such as Tumor Necrosis Factor-α (TNF-α) and interleukin 17 (IL-17), are essential for maintaining psoriatic lesions. Additionally, a hypoxic milieu present in the skin promotes the expression of transcriptional factor hypoxia-inducible factor-1 alpha (HIF-1α). This protein regulates the expression of angiogenic and glycolytic factors, such as vascular endothelial grown factor and lactate dehydrogenase (LDH), both relevant in chronic inflammation. The von Hippel–Lindau protein (pVHL) is a negative regulator of HIF-1α. Previously, we found that pVHL was almost absent in the lesions of psoriasis patients; therefore, we investigated the impact of rescue pVHL expression in lesional skin. We used the imiquimod-induced psoriasis-like mouse model as an adenoviral vector that all...
PD-L1 expression plays a critical role in the impairment of T cell responses during chronic infec... more PD-L1 expression plays a critical role in the impairment of T cell responses during chronic infections; however, the expression of PD-L1 on T cells during acute viral infections, particularly during the pandemic influenza virus (A(H1N1)pdm09), and its effects on the T cell response have not been widely explored. We found that A(H1N1)pdm09 virus induced PD-L1 expression on human dendritic cells (DCs) and T cells, as well as PD-1 expression on T cells. PD-L1 expression impaired the T cell response against A(H1N1)pdm09 by promoting CD8+T cell death and reducing cytokine production. Furthermore, we found increased PD-L1 expression on DCs and T cells from influenza-infected patients from the first and second 2009 pandemic waves in Mexico City. PD-L1 expression on CD8+T cells correlated inversely with T cell proportions in patients infected with A(H1N1)pdm09. Therefore, PD-L1 expression on DCs and T cells could be associated with an impaired T cell response during acute infection with A(H...
The relationship between the neuroendocrine and the immune systems is essential to maintain homeo... more The relationship between the neuroendocrine and the immune systems is essential to maintain homeostasis. Their complex interactions are present in many physiological or pathological states whereby hormones exert different actions in immune system cells and vice versa. Hormones such as prolactin, growth hormone, cortisol and sex hormones are known to regulate the differentiation and function of immune system cells and the production of cytokines. Many of these cells express hormone receptors leading to the tempering of several autoimmune and neoplastic diseases. The pituitary gland is susceptible to autoimmune damage, be it because of primary lymphocytic hypophysitis, as part of IgG4-related disease or as an adverse event of treatment with immune checkpoint inhibitors (ICi). Finally, pituitary adenomas, like many other neoplasms, are frequently infiltrated by different cells of the immune system, a phenomenon that can be related to the degree of invasiveness of these lesions. The purpose of the present work is to critically analyze the neuroendocrine-immune interphase, from both a biological and a clinical perspective.
Revista médica del Instituto Mexicano del Seguro Social, 2012
Ralph M. Steinman fue galardonado con el Premio Nobel de Fisiologia y Medicina 2011 por su descub... more Ralph M. Steinman fue galardonado con el Premio Nobel de Fisiologia y Medicina 2011 por su descubrimiento de las celulas dendriticas, fundamentales en la induccion de respuestas inmunologicas adquiridas necesarias para la defensa del organismo. Actualmente las celulas dendriticas se han aprovechado para el desarrollo de vacunas y terapia oncologica
Nontuberculous mycobacteria (NTM) are recognized as emerging pathogens and their immune regulator... more Nontuberculous mycobacteria (NTM) are recognized as emerging pathogens and their immune regulatory mechanisms are not well described yet. From them, Mycobacterium avium is known to be a weak activator of dendritic cells (DCs) that impairs the response induced by BCG vaccine. However, whether other NTM such as Mycobacterium scrofulaceum may modulate the activation of DCs, has not been extensively studied. Here, we exposed bone marrow-derived DCs (BMDCs) to M. scrofulaceum and we analyzed the effect on the activation of DCs. We found that M. scrofulaceum has a comparable ability to induce a semi-mature DC phenotype, which was produced by its interaction with DC-SIGN and TLR4 receptors in a synergic effect. BMDCs exposed to M. scrofulaceum showed high expression of PD-L2 and production of IL-10, as well as low levels of co-stimulatory molecules and pro-inflammatory cytokines. In addition to immunophenotype induced on DCs, changes in morphology, re-organization of cytoskeleton and decreased migratory capacity are consistent with a semi-mature phenotype. However, unlike other pathogenic mycobacteria, the DC-semi-mature phenotype induced by M. scrofulaceum was reversed after re-exposure to BCG, suggesting that modulation mechanisms of DC-activation used by M. scrofulaceum are different to other known pathogenic mycobacteria. This is the first report about the immunophenotypic characterization of DC stimulated by M. scrofulaceum.
Psoriasis is an inflammatory autoimmune disease characterized by cutaneous lesions in plaques. It... more Psoriasis is an inflammatory autoimmune disease characterized by cutaneous lesions in plaques. It has been proposed that the immune response has a key role in the disease progression. Particularly, the Th17 cells through IL-17 can contribute to maintain the inflammatory process. The pathogenic Th17 phenotype has been described in human diseases and associated with high severity in inflammatory experimental models. However, it is not clear if the pathogenic phenotype could be present in the skin and peripheral blood as well as its possible association to severity in psoriasis. In the lesional skin, we found high infiltration of Th17 cells and the pathogenic phenotype, finding a correlation between the frequency of Th17 cells and the Psoriasis Area and Severity Index (PASI) score. In peripheral blood, we observed a pool of Th17 lymphocytes with potential to acquire pathogenic features. Interestingly, the percentage of pathogenic Th17 cells (CD4+ RORγt+ IFN-γ+) correlates with disease ...
SARS-CoV-2, the etiological agent causing COVID-19, has infected more than 8.7 million people wit... more SARS-CoV-2, the etiological agent causing COVID-19, has infected more than 8.7 million people with over 461000 deaths worldwide since its emergence in December 2019. Factors for severe disease, such as diabetes, hypertension and obesity have been identified however, the precise pathogenesis is poorly understood. In order to understand its pathophysiology and to develop effective therapeutic strategies, it is essential to define the prevailing immune cellular subsets. We performed circulating immune cells scRNAseq from five critically ill COVID-19 patients. Immature myeloid populations, such as promyelocytes-myelocytes, metamyelocytes, band neutrophils, monocytoid precursors and activated monocytes predominated. Trajectory with pseudotime analysis supported the finding of immature cell states. Gene ontology showed myeloid cell activation in immune response, DNA and RNA processing, defense response to virus and response to type 1 interferon. Lymphoid lineage was scarce. Our results un...
CD4 T cells are major players in the immune response against several diseases; including AIDS, le... more CD4 T cells are major players in the immune response against several diseases; including AIDS, leishmaniasis, tuberculosis, influenza and cancer. Their activation has been successfully achieved by administering antigen coupled with antibodies, against DC-specific receptors in combination with adjuvants. Unfortunately, most of the adjuvants used so far in experimental models are unsuitable for human use. Therefore, human DC-targeted vaccination awaits the description of potent, yet nontoxic adjuvants. The nontoxic cholera B subunit (CTB) can be safely used in humans and it has the potential to activate CD4 T cell responses. However, it remains unclear whether CTB can promote DC activation and can act as an adjuvant for DC-targeted antigens. Here, we evaluated the CTB's capacity to activate DCs and CD4 T cell responses, and to generate long-lasting protective immunity. Intradermal (i.d.) administration of CTB promoted late and prolonged activation and accumulation of skin and lymp...
Sporotrichosis is a chronic subcutaneous mycosis caused by the species complex and it is consider... more Sporotrichosis is a chronic subcutaneous mycosis caused by the species complex and it is considered an emerging opportunistic infection in countries with tropical and subtropical climates. The host's immune response has a main role in the development of this disease. However, it is unknown the features of the memory cellular immune response that could protect against the infection. Our results show that i.d. immunization in the ears of mice with inactivated conidia (iC) combined with the cholera toxin (CT) induces a cellular immune response mediated by circulating memory CD4 T cells, which mainly produce interleukin 17 (IL-17). These cells mediate a strong delayed-type hypersensitivity (DTH) reaction. Systemic and local protection against was mediated by circulating CD4 T cells. In contrast, the infection induces a potent immune response in the skin mediated by CD4 T cells, which have an effector phenotype that preferentially produce interferon gamma (IFN-γ) and mediate a transi...
Antigen processing for presentation by major histocompatibility complex class II (MHCII) molecule... more Antigen processing for presentation by major histocompatibility complex class II (MHCII) molecules requires the latter to travel through the endocytic pathway together with its chaperons: the invariant chain (Ii) and DM. Nevertheless, the nature of the compartments where MHCII molecules travel to acquire peptides lacks definition regarding molecules involved in intracellular vesicular trafficking, such as Rab small GTPases. We aimed to define which Rab proteins are present during the intracellular transport of MHCII, DM, and Ii through the endocytic pathway on their route to the cell surface during dendritic cell (DC) maturation. We examined, by means of three-color confocal microscopy, the association of MHCII, DM, and Ii with Rab5, Rab7, Rab9, and Rab11 during the maturation of bone marrow-derived or spleen DC in response to LPS as an inflammatory stimulus. Prior to the stage of immature DC, MHCII migrated from diffuse small cytoplasmic vesicles, predominantly Rab5+Rab7- and Rab5+...
Inhibins are members of the TGFβ superfamily, which regulate many cellular processes including di... more Inhibins are members of the TGFβ superfamily, which regulate many cellular processes including differentiation, proliferation, survival and apoptosis. Although initially described as hormones regulating the hypothalamus-pituitary-gonadal axis, based on their ability to antagonize Activins, our group has recently reported that they play a role in thymocyte differentiation and survival, as well as in thymic stromal cell maturation and nTreg generation. Here, we used Inhibin knock out mice (Inhα-/-) to investigate the role of Inhibins in peripheral dendritic cell maturation and function. We first demonstrated that LPS treated Inhα+/+ bone marrow derived dendritic cells (BMDC) were capable to produce significant levels of Inhibin A. Interestingly, Inhα-/- BMDC showed reduced MHCII and CD86 upregulation and increased PD-L1 expression in response to LPS compared to Inhα+/+, which correlated with reduced ability to induce proliferation of allogeneic T cells. The "semi-mature" phe...
Innate lymphoid cells (ILC) are members of a heterogeneous family with a lymphoid origin that mim... more Innate lymphoid cells (ILC) are members of a heterogeneous family with a lymphoid origin that mimics the T helper (Th) cytokine profile. ILC are involved in early effector cytokine-mediated responses during infections in peripheral tissues. ILC also play an important role in chronic skin inflammatory diseases, including psoriasis. Although classical ILC express CD127, it has been recently reported that the presence of non-classical CD127(-) ILC populations and an early ILC precursor (EILP) CD127(low). ILC development has predominately been investigated in mouse models. However, in humans, different transcription factors have been described for ILC identification. NFIL3 (nuclear factor, IL-3 regulated) is crucial for ILC development in response to IL-7. CD123 (IL-3Rα) is usually used to exclude basophils during ILC identification, however, it is unknown if in response to IL-3, NFIL3 could be relevant to induce ILC features in Lin(-) CD123(+) populations in addition, is also unknown w...
Revista Medica Del Instituto Mexicano Del Seguro Social, Mar 1, 2012
Ralph M. Steinman was the recipient of the 2011 Nobel Prize of Physiology and Medicine due to the... more Ralph M. Steinman was the recipient of the 2011 Nobel Prize of Physiology and Medicine due to the discovery of dendritic cells, which have a crucial role on the onset of acquired immunity, a fundamental event in the organism's defense. Today, dendritic cells are used in the development of vaccines and in cancer therapy. Steinman's contributions have been fundamental in the understanding of immunity.
Uploads
Papers by Laura Bonifaz