DSpace Collection:
https://hdl.handle.net/10171/52122
2024-03-29T07:21:27ZThe evolutionary history of ephs and ephrins: Toward multicellular organisms
https://hdl.handle.net/10171/67548
Title: The evolutionary history of ephs and ephrins: Toward multicellular organisms
Abstract: Eph receptor (Eph) and ephrin signaling regulate fundamental developmental processes through both forward and
reverse signaling triggered upon cell–cell contact. In vertebrates, they are both classified into classes A and B, and some
representatives have been identified in many metazoan groups, where their expression and functions have been well
studied. We have extended previous phylogenetic analyses and examined the presence of Eph and ephrins in the tree of
life to determine their origin and evolution. We have found that 1) premetazoan choanoflagellates may already have
rudimental Eph/ephrin signaling as they have an Eph-/ephrin-like pair and homologs of downstream-signaling genes; 2)
both forward- and reverse-downstream signaling might already occur in Porifera since sponges have most genes involved
in these types of signaling; 3) the nonvertebrate metazoan Eph is a type-B receptor that can bind ephrins regardless of
their membrane-anchoring structure, glycosylphosphatidylinositol, or transmembrane; 4) Eph/ephrin cross-class binding
is specific to Gnathostomata; and 5) kinase-dead Eph receptors can be traced back to Gnathostomata. We conclude that
Eph/ephrin signaling is of older origin than previously believed. We also examined the presence of protein domains
associated with functional characteristics and the appearance and conservation of downstream-signaling pathways to
understand the original and derived functions of Ephs and ephrins. We find that the evolutionary history of these gene
families points to an ancestral function in cell–cell interactions that could contribute to the emergence of multicellularity
and, in particular, to the required segregation of cell populations.2020-01-01T00:00:00ZLong-Term Systemic Expression of a Novel PD-1 Blocking Nanobody from an AAV Vector Provides Antitumor Activity without Toxicity
https://hdl.handle.net/10171/66720
Title: Long-Term Systemic Expression of a Novel PD-1 Blocking Nanobody from an AAV Vector Provides Antitumor Activity without Toxicity
Abstract: Immune checkpoint blockade using monoclonal antibodies (mAbs) able to block
programmed death-1 (PD-1)/PD-L1 axis represents a promising treatment for cancer. However,
it requires repetitive systemic administration of high mAbs doses, often leading to adverse effects.
We generated a novel nanobody against PD-1 (Nb11) able to block PD-1/PD-L1 interaction for
both mouse and human molecules. Nb11 was cloned into an adeno-associated virus (AAV) vector
downstream of four different promoters (CMV, CAG, EF1α, and SFFV) and its expression was
analyzed in cells from rodent (BHK) and human origin (Huh-7). Nb11 was expressed at high levels
in vitro reaching 2–20 micrograms/mL with all promoters, except SFFV, which showed lower levels.
Nb11 in vivo expression was evaluated in C57BL/6 mice after intravenous administration of AAV8
vectors. Nb11 serum levels increased steadily along time, reaching 1–3 microgram/mL two months
post-treatment with the vector having the CAG promoter (AAV-CAG-Nb11), without evidence of
toxicity. To test the antitumor potential of this vector, mice that received AAV-CAG-Nb11, or saline
as control, were challenged with colon adenocarcinoma cells (MC38). AAV-CAG-Nb11 treatment
prevented tumor formation in 30% of mice, significantly increasing survival. These data suggest that
continuous expression of immunomodulatory nanobodies from long-term expression vectors could
have antitumor effects with low toxicity.2020-01-01T00:00:00ZMicroglia and astrocyte activation is region-dependent in the alfa-synuclein mouse model of Parkinson's disease
https://hdl.handle.net/10171/66711
Title: Microglia and astrocyte activation is region-dependent in the alfa-synuclein mouse model of Parkinson's disease
Abstract: Inflammation is a common feature in neurodegenerative diseases that contributes to neuronal loss. Previously, we demonstrated that the basal inflammatory tone differed between brain regions and, consequently, the reaction generated to a pro-inflammatory stimulus was different. In this study, we assessed the innate immune reaction in the midbrain and in the striatum using an experimental model of Parkinson's disease. An adeno-associated virus serotype 9 expressing the α-synuclein and mCherry genes or the mCherry gene was administered into the substantia nigra. Myeloid cells (CD11b+ ) and astrocytes (ACSA2+ ) were purified from the midbrain and striatum for bulk RNA sequencing. In the parkinsonian midbrain, CD11b+ cells presented a unique anti-inflammatory transcriptomic profile that differed from degenerative microglia signatures described in experimental models for other neurodegenerative conditions. By contrast, striatal CD11b+ cells showed a pro-inflammatory state and were similar to disease-associated microglia. In the midbrain, a prominent increase of infiltrated monocytes/macrophages was observed and, together with microglia, participated actively in the phagocytosis of dopaminergic neuronal bodies. Although striatal microglia presented a phagocytic transcriptomic profile, morphology and cell density was preserved and no active phagocytosis was detected. Interestingly, astrocytes presented a pro-inflammatory fingerprint in the midbrain and a low number of differentially displayed transcripts in the striatum. During α-synuclein-dependent degeneration, microglia and astrocytes experience context-dependent activation states with a different contribution to the inflammatory reaction. Our results point towards the relevance of selecting appropriate cell targets to design neuroprotective strategies aimed to modulate the innate immune system during the active phase of dopaminergic degeneration.2023-01-01T00:00:00ZHigh-capacity adenoviral vectors: expanding the scope of gene therapy
https://hdl.handle.net/10171/66613
Title: High-capacity adenoviral vectors: expanding the scope of gene therapy
Abstract: The adaptation of adenoviruses as gene delivery tools has resulted in the development
of high-capacity adenoviral vectors (HC-AdVs), also known, helper-dependent or “gutless”.
Compared with earlier generations (E1/E3-deleted vectors), HC-AdVs retain relevant features
such as genetic stability, remarkable efficacy of in vivo transduction, and production at high titers.
More importantly, the lack of viral coding sequences in the genomes of HC-AdVs extends the cloning
capacity up to 37 Kb, and allows long-term episomal persistence of transgenes in non-dividing
cells. These properties open a wide repertoire of therapeutic opportunities in the fields of gene
supplementation and gene correction, which have been explored at the preclinical level over the past
two decades. During this time, production methods have been optimized to obtain the yield, purity,
and reliability required for clinical implementation. Better understanding of inflammatory responses
and the implementation of methods to control them have increased the safety of these vectors. We will
review the most significant achievements that are turning an interesting research tool into a sound
vector platform, which could contribute to overcome current limitations in the gene therapy field.2020-01-01T00:00:00Z