Experimental approaches for the generation of induced pluripotent stem cells

Derivation of autologous induced pluripotent stem cells (iPSCs) through direct reprogramming of easily accessible somatic cells holds the potential to transform the field of regenerative medicine. Since Takahashi and Yamanaka's groundbreaking study describing the generation of iPSCs by retroviral-mediated delivery of defined transcription factors, substantial progress has been made to improve both the efficiency and safety of the method. These advances have provided new insights into the molecular mechanisms of reprogramming and promise to accelerate the clinical translation of iPSC technology. Here, we summarize current reprogramming methodologies with a focus on the production of transgene-free or genetically unmanipulated iPSCs and highlight important technical details that ultimately may influence the biological properties of pluripotent stem cells

Reprogramming of Human Peripheral Blood Cells to Induced Pluripotent Stem Cells

Embryonic stem cells are pluripotent cells derived from the inner cell mass of the developing embryo that have the capacity to differentiate into every cell type of the adult (Evans and Kaufman, 1981, Martin, 1981, Martin and Evans, 1975 and Thomson et al., 1998). The generation of patient-specific pluripotent cells is therefore an important goal of regenerative medicine. A major step to achieve this was the recent discovery that ectopic expression of defined transcription factors induces pluripotency in somatic cells (Lowry et al., 2008, Park et al., 2008b, Takahashi et al., 2007 and Yu et al., 2007). Until now, the most common source from which to derive human iPSCs has been skin fibroblasts (Lowry et al., 2008, Park et al., 2008a, Park et al., 2008b, Takahashi et al., 2007 and Yu et al., 2009). However, the requirement for skin biopsies and the need to expand fibroblast cells for several passages in vitro represent a hurdle that must be overcome to make iPSC technology broadly applicable. Peripheral blood can be utilized as an easily accessible source of patient tissue for reprogramming. Here we derived iPSCs from frozen human peripheral blood samples. Some of the iPSCs had rearrangements of the T cell receptor (TCR), indicating that T cells can be reprogrammed to pluripotency.National Institutes of Health (U.S.) (Grant 5-RO1-HDO45022)National Institutes of Health (U.S.) (Grant 5-R37-CA084198)National Institutes of Health (U.S.). (Grant 5-RO1-CA087869)National Center for Research Resources (U.S.) (Grant UL1 RR025758

New directions in cellular therapy of cancer: a summary of the summit on cellular therapy for cancer

A summit on cellular therapy for cancer discussed and presented advances related to the use of adoptive cellular therapy for melanoma and other cancers. The summit revealed that this field is advancing rapidly. Conventional cellular therapies, such as tumor infiltrating lymphocytes (TIL), are becoming more effective and more available. Gene therapy is becoming an important tool in adoptive cell therapy. Lymphocytes are being engineered to express high affinity T cell receptors (TCRs), chimeric antibody-T cell receptors (CARs) and cytokines. T cell subsets with more naïve and stem cell-like characteristics have been shown in pre-clinical models to be more effective than unselected populations and it is now possible to reprogram T cells and to produce T cells with stem cell characteristics. In the future, combinations of adoptive transfer of T cells and specific vaccination against the cognate antigen can be envisaged to further enhance the effectiveness of these therapies

A phased SNP-based classification of sickle cell anemia HBB haplotypes

Background: Sickle cell anemia causes severe complications and premature death. Five common beta-globin gene cluster haplotypes are each associated with characteristic fetal hemoglobin (HbF) levels. As HbF is the major modulator of disease severity, classifying patients according to haplotype is useful. The first method of haplotype classification used restriction fragment length polymorphisms (RFLPs) to detect single nucleotide polymorphisms (SNPs) in the beta-globin gene cluster. This is labor intensive, and error prone. Methods: We used genome-wide SNP data imputed to the 1000 Genomes reference panel to obtain phased data distinguishing parental alleles. Results: We successfully haplotyped 813 sickle cell anemia patients previously classified by RFLPs with a concordance >98%. Four SNPs (rs3834466, rs28440105, rs10128556, and rs968857) marking four different restriction enzyme sites unequivocally defined most haplotypes. We were able to assign a haplotype to 86% of samples that were either partially or misclassified using RFLPs. Conclusion: Phased data using only four SNPs allowed unequivocal assignment of a haplotype that was not always possible using a larger number of RFLPs. Given the availability of genome-wide SNP data, our method is rapid and does not require high computational resources.NIH Bethesda, MDBoston Univ, Sch Med, Dept Med, 72 E Concord St, Boston, MA 02118 USABoston Univ, Bioinformat Program, Boston, MA 02215 USAKing Saud Univ, Coll Med, Sickle Cell Dis Res Ctr, Riyadh, Saudi ArabiaKing Saud Univ, Coll Med, Dept Pediat, Riyadh, Saudi ArabiaKing Faisal Univ, Al Omran Sci Chair, Al Hasa, Saudi ArabiaImam Abdulrahman bin Faisal Univ, Inst Res & Med Consultat, Dammam, Saudi ArabiaEscola Paulista Med, Hematol & Blood Transfus Div, São Paulo, BrazilBoston Univ, Sch Publ Hlth, Dept Biostat, Boston, MA 02118 USAEscola Paulista Med, Hematol & Blood Transfus Div, São Paulo, BrazilNIH: R01 HL 068970NIH: RC2 HL 101212NIH: R01 87681NIH: T32 HL007501Web of Scienc

Tet1 and Tet2 Regulate 5-Hydroxymethylcytosine Production and Cell Lineage Specification in Mouse Embryonic Stem Cells

SummaryTET family enzymes convert 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) in DNA. Here, we show that Tet1 and Tet2 are Oct4-regulated enzymes that together sustain 5hmC in mouse embryonic stem cells (ESCs) and are induced concomitantly with 5hmC during reprogramming of fibroblasts to induced pluripotent stem cells. ESCs depleted of Tet1 by RNAi show diminished expression of the Nodal antagonist Lefty1 and display hyperactive Nodal signaling and skewed differentiation into the endoderm-mesoderm lineage in embryoid bodies in vitro. In Fgf4- and heparin-supplemented culture conditions, Tet1-depleted ESCs activate the trophoblast stem cell lineage determinant Elf5 and can colonize the placenta in midgestation embryo chimeras. Consistent with these findings, Tet1-depleted ESCs form aggressive hemorrhagic teratomas with increased endoderm, reduced neuroectoderm, and ectopic appearance of trophoblastic giant cells. Thus, 5hmC is an epigenetic modification associated with the pluripotent state, and Tet1 functions to regulate the lineage differentiation potential of ESCs

Elevated Humoral Immune Response to SARS-CoV-2 at High Altitudes Revealed by an Anti-RBD “In-House” ELISA

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused a global pandemic with dramatic health and socioeconomic consequences. The Coronavirus Disease 2019 (COVID-19) challenges health systems to quickly respond by developing new diagnostic strategies that contribute to identify infected individuals, monitor infections, perform contact-tracing, and limit the spread of the virus. In this brief report, we developed a highly sensitive, specific, and precise “In-House” ELISA to correctly discriminate previously SARS-CoV-2-infected and non-infected individuals and study population seroprevalence. Among 758 individuals evaluated for anti-SARS-CoV-2 serology in the province of Tucumán, Argentina, we found a weak correlation between antibodies elicited against the RBD, the receptor-binding domain of the Spike protein, and the nucleocapsid (N) antigens of this virus. Additionally, we detected mild levels of anti-RBD IgG antibodies in 33.6% of individuals diagnosed with COVID-19, while only 19% showed sufficient antibody titers to be considered as plasma donors. No differences in IgG anti-RBD titers were found between women and men, neither in between different age groups ranging from 18 to 60. Surprisingly, individuals from a high altitude village displayed elevated and longer lasting anti-RBD titers compared to those from a lower altitude city. To our knowledge, this is the first report correlating altitude with increased humoral immune response against SARS-CoV-2 infection.Fil: Tomas Grau, Rodrigo Hernán. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Ploper, Diego. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Avila, Cesar Luis. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Vera Pingitore, Esteban. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Maldonado Galdeano, María Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Chaves, Analia Silvina. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Socias, Sergio Benjamin. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Stagnetto, Agustín. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Navarro, Silvia Adriana. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Chahla, Rossana Elena. Gobierno de la Provincia de Tucumán. Ministerio de Salud; ArgentinaFil: Aguilar López, Mónica. Gobierno de la Provincia de Tucuman. Hospital de Dia Presidente Nestor Carlos Kirchner; ArgentinaFil: Llapur, Conrado Juan. Gobierno de la Provincia de Tucumán. Ministerio de Salud; ArgentinaFil: Aznar, Patricia. Gobierno de la Provincia de Tucuman. Hospital de Dia Presidente Nestor Carlos Kirchner; ArgentinaFil: Alcorta, María Elena. Gobierno de la Provincia de Tucuman. Hospital de Dia Presidente Nestor Carlos Kirchner; ArgentinaFil: Costas, Dardo. Gobierno de la Provincia de Tucuman. Hospital de Dia Presidente Nestor Carlos Kirchner; ArgentinaFil: Flores, Isolina. Gobierno de la Provincia de Tucuman. Hospital de Dia Presidente Nestor Carlos Kirchner; ArgentinaFil: Heinze, Dar. University of Boston. School of Medicine; Estados UnidosFil: Apfelbaum, Gabriela. Universidad Nacional de Tucumán; ArgentinaFil: Mostoslavsky, Raul. Harvard Medical School; Estados UnidosFil: Mostoslavsky, Gustavo. Harvard Medical School; Estados UnidosFil: Cazorla, Silvia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Perdigon, Gabriela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Chehin, Rosana Nieves. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; Argentin

Lineage conversion induced by pluripotency factors involves transient passage through an iPS cell stage

Brief expression of pluripotency-associated factors such as Oct4, Klf4, Sox2 and c-Myc (OKSM), in combination with differentiation-inducing signals, was reported to trigger transdifferentiation of fibroblasts into other cell types. Here we show that OKSM expression in mouse fibroblasts gives rise to both induced pluripotent stem cells (iPSCs) and induced neural stem cells (iNSCs) under conditions previously shown to induce only iNSCs. Fibroblast-derived iNSC colonies silenced retroviral transgenes and reactivated silenced X chromosomes, both hallmarks of pluripotent stem cells. Moreover, lineage tracing with an Oct4-CreER labeling system demonstrated that virtually all iNSC colonies originated from cells transiently expressing Oct4, whereas ablation of Oct4+ cells prevented iNSC formation. Lastly, an alternative transdifferentiation cocktail that lacks Oct4 and was reportedly unable to support induced pluripotency yielded iPSCs and iNSCs carrying the Oct4-CreER-derived lineage label. Together, these data suggest that iNSC generation from fibroblasts using OKSM and other pluripotency-related reprogramming factors requires passage through a transient iPSC state

Long-term analysis of antibodies elicited by SPUTNIK V: A prospective cohort study in Tucumán, Argentina

Background: Gam-COVID-Vac (SPUTNIK V) has been granted emergency use authorization in 70 nations and has been administered to millions worldwide. However, there are very few peer-reviewed studies describing its effects. Independent reports regarding safety and effectiveness could accelerate the final approval by the WHO. We aimed to study the long-term humoral immune response in nay¨ve and previously infected volunteers who received SPUTNIK V. Methods: Humoral immune responses, assayed by anti-SARS-CoV-2-spike-RBD IgG ELISA and neutralization assays, were measured in 602 healthcare workers at 0, 14, 28, 60 and 180 days after receiving SPUTNIK V between December 2020 and July 2021 in Tucuman, Argentina. Findings: Seroconversion was detected in 97% of individuals after 28 days post-vaccination (dpv) (N = 405). Anti-RBD titers began to decrease after 60 dpv (N = 328), but remained detectable in 94% at 90 dpv (N = 224). At 180 dpv, anti-RDB titers persisted in 31% (N = 146). Previous infection triggered an increased immune response to the first dose and increased neutralization activity against variants of concern (VOC). Second doses in previously infected individuals further increased titers, even 90 dpv (N = 75). Basal antibody titers had more influence on postvaccination anti-RBD responses than the time elapsed between diagnosis and vaccination (N = 274). Interpretation: Data presented herein provides essential knowledge regarding the kinetics of antibodies induced by SPUTNIK V up to six months after immunization, and suggests that when considering one-dose vaccination policies for individuals with previous SARS-CoV-2 infection, serological studies to determine basal titers may be important, independent of when diagnosis occurred.Fil: Chahla, Rossana Elena. Ministerio de Salud Pública de Tucumán; ArgentinaFil: Tomas Grau, Rodrigo Hernán. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Cazorla, Silvia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Ploper, Diego. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Vera Pingitore, Esteban. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Aguilar López, Mónica. Gobierno de la Provincia de Tucuman. Ministerio de Salud. Departamento Bioquimico. Laboratorio de Salud Publica.; ArgentinaFil: Aznar, Patricia. Gobierno de la Provincia de Tucuman. Ministerio de Salud. Departamento Bioquimico. Laboratorio de Salud Publica.; ArgentinaFil: Alcorta, María Elena. Gobierno de la Provincia de Tucuman. Ministerio de Salud. Departamento Bioquimico. Laboratorio de Salud Publica.; ArgentinaFil: Velez, Eva Maria del Mar. Gobierno de la Provincia de Tucuman. Ministerio de Salud. Departamento Bioquimico. Laboratorio de Salud Publica.; ArgentinaFil: Stagnetto, Agustín. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Avila, Cesar Luis. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Maldonado Galdeano, María Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Socias, Sergio Benjamin. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Heinze, Dar. University Of Boston. School Of Medicine. Center For Regenerative Medicine.; Estados UnidosFil: Navarro, Silvia Adriana. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Llapur, Conrado Juan. Ministerio de Salud Pública de Tucumán; ArgentinaFil: Costas, Dardo. Gobierno de la Provincia de Tucuman. Ministerio de Salud. Departamento Bioquimico. Laboratorio de Salud Publica.; ArgentinaFil: Flores, Isolina. Gobierno de la Provincia de Tucuman. Ministerio de Salud. Departamento Bioquimico. Laboratorio de Salud Publica.; ArgentinaFil: Edelstein, Alexis. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Kowdle, Shreyas. Icahn School of Medicine at Mount Sinai; Estados UnidosFil: Perandones, Claudia. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Lee, Benhur. Icahn School of Medicine at Mount Sinai; Estados UnidosFil: Apfelbaum, Gabriela. Universidad Nacional de Tucumán; ArgentinaFil: Mostoslavsky, Raul. Harvard Medical School; Estados UnidosFil: Mostoslavsky, Gustavo. University Of Boston. School Of Medicine. Center For Regenerative Medicine.; Estados UnidosFil: Perdigon, Gabriela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Chehin, Rosana Nieves. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; Argentin

Impaired intrinsic immunity to HSV-1 in human iPSC-derived TLR3-deficient CNS cells

In the course of primary infection with herpes simplex virus 1 (HSV-1), children with inborn errors of TLR3 immunity are prone to HSV-1 encephalitis (HSE) 1–3. We tested the hypothesis that the pathogenesis of HSE involves non hematopoietic central nervous system (CNS)-resident cells. We derived induced pluripotent stem cells (iPSCs) from the dermal fibroblasts of TLR3- and UNC-93B-deficient patients and from controls. These iPSCs were differentiated into highly purified populations of neural stem cells (NSCs), neurons, astrocytes and oligodendrocytes. The induction of IFN-β and/or IFN-γ1 in response to poly(I:C) stimulation was dependent on TLR3 and UNC-93B in all cells tested. However, the induction of IFN-β and IFN-γ1 in response to HSV-1 infection was impaired selectively in UNC-93B-deficient neurons and oligodendrocytes. These cells were also much more susceptible to HSV-1 infection than control cells, whereas UNC-93B-deficient NSCs and astrocytes were not. TLR3-deficient neurons were also found to be susceptible to HSV-1 infection. The rescue of UNC-93B- and TLR3-deficient cells with the corresponding wild-type allele demonstrated that the genetic defect was the cause of the poly(I:C) and HSV-1 phenotypes. The viral infection phenotype was further rescued by treatment with exogenous IFN-α/β, but not IFN-γ1.Thus, impaired TLR3- and UNC-93B-dependent IFN-α/β intrinsic immunity to HSV-1 in the CNS, in neurons and oligodendrocytes in particular, may underlie the pathogenesis of HSE in children with TLR3 pathway deficiencies