Disturbances in the IgG Antibody Profile in HIV-Exposed Uninfected Infants Associated with Maternal Factors.

Over the last 20 years, the incidence of vertical HIV transmission has decreased from 25%-42% to less than 1%. Although there are no signs of infection, the health of HIV-exposed uninfected (HEU) infants is notoriously affected during the first months of life, with opportunistic infections being the most common disease. Some studies have reported effects on the vertical transfer of antibodies, but little is known about the subclass distribution of these antibodies. We proposed to evaluate the total IgG concentration and its subclasses in HIV+ mothers and HEU pairs and to determine which maternal factors condition their levels. In this study, plasma from 69 HEU newborns, their mothers, and 71 control pairs was quantified via immunoassays for each IgG isotype. Furthermore, we followed the antibody profile of HEUs throughout the first year of life. We showed that mothers present an antibody profile characterized by high concentrations of IgG1 and IgG3 but reduced IgG2, and HEU infants are born with an IgG subclass profile similar to that of their maternal pair. Interestingly, this passively transferred profile could remain influenced even during their own antibody production in HEU infants, depending on maternal conditions such as CD4+ T-cell counts and maternal antiretroviral treatment. Our findings indicate that HEU infants exhibit an altered IgG subclass profile influenced by maternal factors, potentially contributing to their increased susceptibility to infections.

Viral infections in stillbirth: a contribution underestimated in Mexico?

OBJECTIVES: To analyze the role of viral infections as etiology of stillbirths in Mexico and their epidemiological impact in the context of the global Every Newborn Initiative. METHODS: A comprehensive literature search was performed in electronic databases related to stillbirth and viral infections published prior to January 19th 2021. Stillbirths records and causes from National Mexican databases, during 2008-2019 period were also computed. RESULTS: Only two articles with a direct relationship between viral infection and stillbirth were found, and one article with an indirect serological association was identified. During the analyzed period there were 198,076 stillbirths, with a National stillbirth rate (SBR) ranging from 6.9 to 6.5 between 2008 and 2014, with a subsequent increase to reach 7.7 in 2019. Only 19 cases were attributed to viral causes and a specific virus was identified in 11. The main causes of early stillbirth were a fetus with premature rupture of membranes and light for gestational age, and for late stillbirth these were fetus affected by oligohydramnios and slow fetal growth. The percentage classified as unspecified deaths varied from 34.4-41.9%. CONCLUSIONS: In Mexico, there has been an increase in SBR during last years, but the goals of the Every Newborn Initiative is met. More than 14,500 stillbirths with at least 5,100 unspecified cases have been reported per year, and only 11 cases were attributable to a specific virus, highlighting the serious underestimation of cases and the need of implementation of routine viral diagnosis methods to improve the care of this global health problem.

Impaired T helper cell responses in human immunodeficiency virus-exposed uninfected newborns.

INTRODUCTION: HIV-exposed uninfected (HEU) newborns suffer from higher risks of opportunistic infections during the first months of life compared to HIV-unexposed uninfected (HUU) newborns. Alterations in thymic mass, amounts of T helper (Th) cells, T-cell receptor diversity, and activation markers have been found in HEU newborns, suggesting alterations in T cell ontogeny and differentiation. However, little is known about the ability of these cells to produce specialized Th responses from CD4+ T cells. METHOD: To characterize the Th cell profile, we evaluated the frequency of Th1 (CD183+ CD194- CD196- /CXCR3+ CCR4- CCR6- ), Th2 (CD183- CD194+ CD196- /CXCR3- CCR4+ CCR6- ), Th17 (CD183- CD194+ CD196+ /CXCR3- CCR4+ CCR6+ ), and CD4+ CD25++ blood T-cell phenotypes in 50 HEU and 25 HUU newborns. Early activation markers on CD4+ T cells and the Th cytokine profile produced from mononuclear cells under polyclonal T cell stimulation were also studied. Additionally, we probed the ability of CD4+ T cells to differentiate into interferon (IFN)-γ-producing Th1 CD4+ T cells in vitro. RESULTS: Lower percentages of differentiated Th1 , Th2 , Th17, and CD4+ CD25++ T cells were found in blood from HEU newborns than in blood from HUU newborns. However, polyclonally stimulated Th cells showed a similar ability to express CD69 and CD279 but produced less secreted interleukin (IL)-2 and IL-4. Interestingly, under Th1 differentiation conditions, the percentages of CD4+ IFN-γ+ T cells and soluble IFN-γ were higher in HEU newborns than in HUU newborns. CONCLUSION: HEU neonates are born with reduced proportions of differentiated Th1 /Th2 /Th17 and CD4+ CD25++ T cells, but the intrinsic abilities of CD4+ T cells to acquire a Th1 profile are not affected by the adverse maternal milieu during development.

Embryonic neural stem/progenitor cells as model to characterize dystrophin and dystrophin-associated proteins expression during neuronal or astrocytic differentiation.

Neural stem/progenitor cells (NSPC) are multipotent cells that renew themselves and could differentiate into neurons and macro glia (astrocytes and oligodendrocytes) of the nervous system during embryonic development. Duchenne muscular dystrophy is a severe type of muscular dystrophy caused by mutations in the dmd gene, and one-third of patients cursed with neuro-cognitive impairments. In this data article, we take advantage of the differentiation capacity of NSPC as a model to increase our knowledge in the neuronal and/or astrocytic differentiation and to evaluate the expression of dystrophins and dystrophin-associated proteins. We showed the characterization of undifferentiated and neuron and/or astrocyte differentiated NSPC. In addition, we evaluated the expression and subcellular localization of dystrophins and ß-dystroglycan in undifferentiated NSPC and differentiated to neurons and astrocytes.•Primary culture of NSPC was characterized by the expression of multipotent markers nestin and Sox2.•Neuronal or astrocytic differentiation of NSPC was performed by basic fibroblast growth factor (FGF2) withdrawal, histamine or ciliary neurotrophic factor (CNTF) treatment, and expression of ßIII-tubulin or glial fibrillary acidic protein (GFAP) as differentiation markers for neurons or astrocytes was evaluated.•This study will contribute to the understanding of dystrophins and dystrophin-associated proteins expression and function during neuronal or astrocytic differentiation of NSPC.

Characterization of the expression of dystrophins and dystrophin-associated proteins during embryonic neural stem/progenitor cell differentiation.

Duchenne muscular dystrophy (DMD) is a genetic disease caused by mutations in the dystrophin gene. Dystrophin is required for the organization of a complex consisting of dystroglycans, sarcoglycans, dystrobrevins and syntrophins, known as the dystrophin-associated proteins complex (DAPC). In addition to muscle degeneration, cognitive impairment has been reported in DMD patients. To characterize a suitable model for studying the embryonic cerebral functions of dystrophin, we analyzed the expression patterns of dystrophins/DAPC in undifferentiated and differentiated embryonic neural stem/progenitor cells (NSPC). We found that NSPC express mRNAs for dystrophins Dp427, Dp140, Dp71 and Dp40; ß-dystroglycan; α- and ß-dystrobrevin; α1-, ß1-, ß2- and γ2-syntrophin; and ß-, γ-, δ- and ε-sarcoglycan. Some of these were differentially regulated during neuronal or astrocytic differentiation. Interestingly, the protein expression levels of Dp140, ß-dystroglycan and α2-dystrobrevin were also differentially regulated. Additionally, we found that proliferating NSPC and differentiated neurons and astrocytes show immuno-positive staining for dystrophins and ß-dystroglycan. Our results show that dystrophins and DAPC components are expressed and regulated during the neuronal or astrocytic differentiation of NSPC, suggesting that these proteins may have different roles in the brain development.

Utility of two DNA extraction methods using formalin-fixed paraffin-embedded tissues in identifying congenital cytomegalovirus infection by polymerase chain reaction.

Formalin-fixed paraffin-embedded (FFPE) tissues are a source of biological material for molecular studies; several methods to extract DNA from FFPE tissues have been reported. This process is challenging because of formaldehyde-induced cross-linking between proteins and DNA as well as molecule fragmentation when unbuffered formalin is used for fixation. Here, 2 methods for DNA extraction from FFPE tissues, based on a chelating resin and silica membrane columns, were modified and compared in their capacity to detect human cytomegalovirus (HCMV) in congenital infections. Both methods were tested on 121 samples of brain, lung, spleen, and liver derived from 36 deceased preterm newborns. Twelve patients were selected, and UL55 and UL75 HCMV genes were detected by polymerase chain reaction in 16/36 samples. These 2 methods represent a useful tool for DNA recovery from FFPE tissues and HCMV molecular identification with the advantage of low cost, minimal steps, minimal sample use, being solvent-free, and being easy to implement in the laboratory.

Congenital Zika Syndrome and Extra-Central Nervous System Detection of Zika Virus in a Pre-term Newborn in Mexico.

BACKGROUND: During pregnancy, the Zika virus (ZIKV) replicates in the placenta and central nervous system (CNS) of infected fetuses; nevertheless, the ability of ZIKV to replicate in other fetal tissues has not been extensively characterized. METHODS: We researched whether dissemination of congenitally-acquired ZIKV outside the CNS exists by searching for the accumulation of the viral envelope protein, ZIKV ribonucleic acid (RNA), and infectious viral particles in different organs of a deceased newborn with Congenital Zika Syndrome. A real-time qualitative polymerase chain reaction (qPCR) was used to detect ZIKV RNA in the brain, thymus, lungs, kidneys, adrenal glands, spleen, liver, and small intestine. The same tissues were analyzed by indirect immunofluorescence and immunoperoxidase assays using the monoclonal antibody 4G2 to detect ZIKV envelope antigens. Isolation of infectious ZIKV in a cell culture was carried out using brain and kidney samples. RESULTS: A postmortem, virological analysis of multiple organs, such as the kidneys (epithelial cells in the renal tubules), lungs (bronchial epithelia), thymus (epithelial cells inside the Hassall's corpuscles), and brain (neurons, ependymal cells, and macrophages) revealed the presence of ZIKV RNA and envelope antigens. Other tissues of the deceased newborn tested positive by qPCR for Epstein-Barr virus and human herpesvirus 6, including the brain cortex (Epstein-Barr) and the thymus, kidneys, and adrenal glands (human herpesvirus 6). The kidneys were identified as a significant niche for viral replication, given that infectious particles were successfully isolated from renal tissues. CONCLUSIONS: Our findings demonstrate the ability of congenitally-acquired ZIKV to produce disseminated infections and the viral tropism towards epithelial cells.

Trypanocidal and toxicological assessment in vitro and in silico of three sesquiterpene lactones from Asteraceae plant species.

We report the effect of the Sesquiterpene Lactones Ambrosin, Incomptine B and Glaucolide E against seven strains of Trypanosoma cruzi, the etiological agent of Chagas Disease. These compounds were isolated from Parthenium hysterophorus, Decachaeta incompta, and Vernonia liatroides, respectively. We evaluated by flow cytometry the viability of epimastigotes. Ambrosin was the most effective, then Incomptine B, and Glaucolide E (IC50 = 67.1, 123.7, and 215.1 µM, respectively). These compounds were more potent than the drugs Benznidazole (IC50 > 400 µM) and Nifurtimox (IC50 = 199.7 to >400 µM). Toxicity to mammalian Vero and Jurkat cells was also determined in vitro. All the compounds had a poor selective index (0.003-1.859). Toxicoinformatics is useful to forecast in silico toxicological and pharmacokinetic properties. Ambrosin and Incomptine B may not possess mutagenic, tumorigenic, or reproductive effects. Glaucolide E could possess a low mutagenic and high tumorigenic effects, and probably target the Amine Oxidase A, Prostaglandin and G/H Synthase I. Interestingly, Ambrosin, Incomptine B and Glaucolide E, comply with Lipinsky Rule of Five, indicating a suitable pharmacokinetic profile. Ambrosin and Incomptine B possess high trypanocidal activity, and pharmaceutical properties suitable for development; however, their safety profile should be optimized by structural modifications.

Cellular and molecular mechanisms of viral infection in the human placenta.

The placenta is a highly specialized organ that is formed during human gestation for conferring protection and generating an optimal microenvironment to maintain the equilibrium between immunological and biochemical factors for fetal development. Diverse pathogens, including viruses, can infect several cellular components of the placenta, such as trophoblasts, syncytiotrophoblasts and other hematopoietic cells. Viral infections during pregnancy have been associated with fetal malformation and pregnancy complications such as preterm labor. In this minireview, we describe the most recent findings regarding virus-host interactions at the placental interface and investigate the mechanisms through which viruses may access trophoblasts and the pathogenic processes involved in viral dissemination at the maternal-fetal interface.

Overexpression of mutant dystrophin Dp71[INCREMENT]78-79 stimulates cell proliferation.

Dp71 dystrophin is the main DMD gene product expressed in the central nervous system. Experiments using PC12 cells as a neuronal model have shown that Dp71 isoforms are involved in differentiation, adhesion, cell division, and nuclear architecture. To contribute to the knowledge of Dp71 domains function, we previously reported the isolation and partial characterization of the dystrophin Dp71[INCREMENT]78-79 (a mutant that lacks exons 71, 78, and 79), which stimulates the neuronal differentiation of PC12-C11 clone. In this article, we generated a doxycycline (Dox)-inducible expression system in PC12 Tet-On cells (B10 cells) to overexpress and control the transcription of Dp71[INCREMENT]78-79. Western blotting and confocal microscopy showed an increase in the amount of Dp71[INCREMENT]78-79 (217±75-fold) with the addition of Dox to growth medium. Cell proliferation assays and morphometric analyses demonstrated that Dp71[INCREMENT]78-79 increases the growth rate of B10 cells and reduces the nerve growth factor-neuronal differentiation. Western blotting analysis revealed an upregulation in the expression of proliferating cell nuclear antigen, focal adhesion kinase, and ß-dystroglycan in B10 cells compared with control cells. Our results show that the inducible expression of Dp71[INCREMENT]78-79 increases the growth rate of PC12 Tet-On cells, suggesting a role of this protein in cell proliferation.

Identification of Dp71 Isoforms Expressed in PC12 Cells: Subcellular Localization and Colocalization with ß-Dystroglycan and α1-Syntrophin.

Several dystrophin Dp71 messenger RNA (mRNA) alternative splice variants have been described. According to the splicing of exon 78 or intron 77, Dp71 proteins are grouped as Dp71d, Dp71f, and Dp71e, and each group has a specific C-terminal end. In this study, we explored the expression of Dp71 isoforms at the complementary DNA (cDNA) level and the subcellular localization of recombinant Myc-Dp71 proteins in PC12 cells. We determined that PC12 cells express Dp71a, Dp71c, Dp71ab, Dp71e, and Dp71ec mRNA splice variants. In undifferentiated and nerve growth factor-differentiated PC12 Tet-ON cells, Dp71a, Dp71ab, and Dp71e were found to localize and colocalize with ß-dystroglycan and α1-syntrophin in the periphery/cytoplasm, while Dp71c and Dp71ec were mainly localized in the cell periphery and showed less colocalization with ß-dystroglycan and α1-syntrophin. The levels of Dp71a, Dp71e, and Dp71ec were increased in the nucleus of differentiated PC12 Tet-ON cells compared to undifferentiated cells. Dp71 isoforms were also localized in neurite extensions and growth cones.