The impact of the COVID-19 pandemic on the Galapagos Islands' seafood system from consumers' perspectives.

The COVID-19 pandemic's early stages severely impacted global fisheries, particularly areas heavily reliant on imported food and tourism like the Galapagos Islands, Ecuador. To contain the spread of the virus, a full lockdown was implemented. However, the collapse of the tourism industry precipitated the worst economic crisis in the history of this multiple-use marine protected area. This paper examines the impact of the pandemic's early stages on consumption patterns and seafood security in the Galapagos from consumers' perspective, drawing on online surveys conducted during the lockdown. Our findings revealed pre-existing seafood insecurity across the archipelago, further exacerbated by the pandemic on the least-populated island. Nevertheless, the seafood system displayed moderated resilience to the pandemic's socioeconomic disruptions. A variety of adaptive responses were adopted by Galapagos residents to cope with the lockdown. Consumers modified their seafood consumption habits, while fishers adapted their harvesting and marketing strategies. Such adaptive responses were shaped by the unique socioeconomic characteristics of each inhabited island and the ability of seafood suppliers to shift from a tourism- and export-oriented to a resident- and domestic-oriented market. This transition has created novel opportunities to foster a systemic transformation of the Galapagos seafood system to enhance its resilience against future crises caused by new pandemics, climate change, or other natural and anthropogenic drivers of change.

Fishing during the "new normality": social and economic changes in Galapagos small-scale fisheries due to the COVID-19 pandemic.

The crisis caused by COVID-19 has profoundly affected human activities around the globe, and the Galapagos Islands are no exception. The impacts on this archipelago include the impairment of tourism and the loss of linkages with the Ecuadorian mainland, which has greatly impacted the local economy. The collapse of the local economy jeopardized livelihoods and food security, given that many impacts affected the food supply chain. During the crisis, the artisanal fishers of the Galapagos showed a high capacity to adapt to the diminishing demand for fish caused by the drastic drop in tourism. We observed that fishers developed strategies and initiatives by shifting roles, from being mainly tourism-oriented providers to becoming local-household food suppliers. This new role of fishers has triggered an important shift in the perception of fishers and fisheries in Galapagos by the local community. The community shifted from perceiving fisheries as a sector opposed to conservation and in conflict with the tourism sector to perceiving fisheries as the protagonist sector, which was securing fresh, high-quality protein for the human community. This study explores the socio-economic impacts and adaptations of COVID-19 on Galapagos' artisanal fisheries based on a mixed methods approach, including the analysis of fisheries datasets, interviews, surveys, and participant observation conducted during and after the lockdown. We illustrate the adaptive mechanisms developed by the sector and explore the changes, including societal perceptions regarding small-scale fisheries in the Galapagos. The research proposes strategies to enhance the Galapagos' economic recovery based on behaviors and traits shown by fishers which are considered potential assets to build-up resilience. Supplementary Information: The online version contains supplementary material available at 10.1007/s40152-022-00268-z.

Strategic nonmyeloablative conditioning: CD154:CD40 costimulatory blockade at primary bone marrow transplantation promotes engraftment for secondary bone marrow transplantation after engraftment failure.

There is an increased risk of failure of engraftment following nonmyeloablative conditioning. Sensitization resulting from failed bone marrow transplantation (BMT) remains a major challenge for secondary BMT. Approaches to allow successful retransplantation would have significant benefits for BMT candidates living with chronic diseases. We used a mouse model to investigate the effect of preparative regimens at primary BMT on outcome for secondary BMT. We found that conditioning with TBI or recipient T cell lymphodepletion at primary BMT did not promote successful secondary BMT. In striking contrast, successful secondary BMT could be achieved in mice conditioned with anti-CD154 costimulatory molecule blockade at first BMT. Blockade of CD154 alone or combined with T cell depletion inhibits generation of the humoral immune response after primary BMT, as evidenced by abrogation of production of anti-donor Abs. The humoral barrier is dominant in sensitization resulting from failed BMT, because almost all CFSE-labeled donor cells were killed at 0.5 and 3 h in sensitized recipients in in vivo cytotoxicity assay, reflecting Ab-mediated cytotoxicity. CD154:CD40 costimulatory blockade used at primary BMT promotes allogeneic engraftment in secondary BMT after engraftment failure at first BMT. The prevention of generation of anti-donor Abs at primary BMT is critical for successful secondary BMT.

Intranuclear staining of proteins in heterogeneous cell populations and verification of nuclear localization by flow cytometric analysis.

We describe techniques to detect nuclear transcription factors in thymocyte subsets using flow cytometry. We have adapted a method that minimizes autofluorescence of fixed cells, thereby allowing the detection of proteins expressed at low levels. An accompanying method in which the cytoplasm is removed from stained cells allows the confirmation of nuclear localization. These methods combine to provide a sensitive alternative approach for detecting nuclear proteins within heterogeneous cell populations.

A delay in bone marrow transplantation after partial conditioning improves engraftment.

BACKGROUND: In the present study we examined the effect of the timing of marrow infusion on engraftment in nonmyeloablatively conditioned mice. METHODS: B10 mice were conditioned with decreasing doses of total body irradiation (TBI) and reconstituted with bone marrow cells (BMCs) from major histocompatibility complex-disparate donor B10.BR mice at 0 or 6 hr, or on days 1, 2, 3, 4, 5, 8, and 12 with respect to TBI. RESULTS: After undergoing conditioning with 700 cGy TBI and transplantation with 15 x 10(6) BMCs, 100% of recipients engrafted if the marrow was infused between 0 and 4 days after TBI. For lower doses of TBI, a delay in infusion of the marrow after TBI conditioning was associated with a significant increase in engraftment. Significantly less engraftment was achieved in animals conditioned with 600 cGy TBI if the marrow was infused at 0 or 6 hr compared with a 1- to 4-day delay. When the TBI was decreased to 500 cGy, engraftment occurred only when the transplant was performed between days 2 and 8. The highest proportion of recipients engrafted when the marrow was infused on day 4. This enhanced engraftment after a delay in marrow infusion is associated with a significant reduction in host mixed lymphocyte reaction reactivity and is correlated inversely with serum levels of interleukin-6 in the recipient. CONCLUSIONS: These data demonstrate for the first time that a delay between conditioning and marrow infusion significantly improves allogeneic engraftment in nonmyeloablatively conditioned recipients and reduces the total conditioning required.

TNF-alpha is critical to facilitate hemopoietic stem cell engraftment and function.

The use of tolerogenic cells as an approach to induce tolerance to solid organ allografts is being aggressively pursued. A major limitation to the clinical application of cell-based therapies has been the ability to obtain sufficient numbers and also preserve their tolerogenic state. We previously reported that small numbers of bone marrow-derived CD8+/TCR- graft facilitating cells (FC) significantly enhance hemopoietic stem cell (HSC) engraftment in allogeneic and syngeneic recipients. Although the majority of FC resemble precursor plasmacytoid dendritic cells (p-preDC), p-preDC do not replace FC in facilitating function. In the present studies, we investigated the mechanism of FC function. We show for the first time that FC significantly enhance HSC clonogenicity, increase the proportion of multipotent progenitors, and prevent apoptosis of HSC. These effects require direct cell:cell contact between FC and HSC. Separation of FC from HSC by transwell membranes completely abrogates the FC effect on HSC. p-preDC FC do not replace FC total in these effects on HSC function. FC produce TNF-alpha, and FC from TNF-alpha-deficient mice exhibit impaired facilitation in vivo and loss of the in vitro effects on HSC. Neutralizing TNF-alpha in FC similarly blocks the FC effect. The antiapoptotic effect of FC is associated with up-regulation of Bcl-3 transcripts in HSC and blocking of TNF-alpha is associated with abrogation of up-regulation of Bcl-3 transcripts. These data demonstrate a critical role for TNF-alpha in mediating FC function. FC may have a significant impact upon the safe use of chimerism to establish tolerance to transplanted organs and tissue.

Flt3-ligand-mobilized peripheral blood, but not Flt3-ligand-expanded bone marrow, facilitating cells promote establishment of chimerism and tolerance.

Facilitating cells (CD8+/TCR-) (FCs) enhance engraftment of limiting numbers of hematopoietic stem cells (HSCs). The primary component of FCs is precursor-plasmacytoid dendritic cells (p-preDCs), a tolerogenic cell expanded by Flt3-ligand (FL). In this study, we evaluated the function and composition of FL-expanded FCs. FL treatment resulted in a significant increase of FCs in bone marrow (BM) and peripheral blood (PB). When FL-expanded FCs were transplanted with c-Kit+/Sca-1+/Lin- (KSL) cells into allogeneic recipients, BM-FCs exhibited significantly impaired function whereas PB-FCs were potently functional. A significant upregulation of P-selectin expression and downregulation of VCAM-1 (vascular cell adhesion molecule 1) were present on FL-expanded PB-FCs compared with FL BM-FCs. Stromal cell-derived factor-1 (SDF-1), and CXCR4 transcripts were significantly increased in FL PB-FCs and decreased in FL BM-FCs. Supernatant from FL PB-FCs primed HSC migration to SDF-1, confirming production of the protein product. The FL PB-FCs contained a predominance of p-preDCs and natural killer (NK)-FCs, and NK-FCs were lacking in FL BM-FCs. The impaired function for BM-FCs was restored within 5 days after cessation of treatment. Taken together, these data suggest that FCs may enhance HSC homing and migration via the SDF-1/CXCR4 axis and adhesion molecule modulation. These findings may have implications in development of strategies for retaining function of ex vivo manipulated FCs and HSCs.

Humoral immunity is the dominant barrier for allogeneic bone marrow engraftment in sensitized recipients.

We evaluated the relative contribution of the humoral and cellular arms of the immune response to bone marrow cells transplanted into sensitized recipients. We report here for the first time that humoral immunity contributes predominantly to allosensitization. Although the major role for nonmyeloablative conditioning is to control alloreactive host T cells in nonsensitized recipients, strikingly, none of the strategies directed primarily at T-cell alloreactivity enhanced engraftment in sensitized mice. In evaluating the mechanism behind this barrier, we found that humoral immunity plays a critical role in the rejection of allogeneic marrow in sensitized recipients. Adoptive transfer of as little as 25 microL serum from sensitized mice abrogated engraftment in secondary naive recipients. With the use of microMT mice as recipients, we found that T-cell-mediated immunity plays a secondary but still significant role in allorejection. Targeting of T cells in sensitized B-cell-deficient microMT mice enhanced alloengraftment. Moreover, both T- and B-cell tolerance were achieved in sensitized recipients when allochimerism was established, as evidenced by the acceptance of second donor skin grafts and loss of circulating donor-specific Abs. These findings have important implications for the management of sensitized transplant recipients and for xenotransplantation in which B-cell reactivity is a predominant barrier.

Hematopoietic stem cells from NOD mice exhibit autonomous behavior and a competitive advantage in allogeneic recipients.

Type 1 diabetes is a systemic autoimmune disease that can be cured by transplantation of hematopoietic stem cells (HSCs) from disease-resistant donors. Nonobese diabetic (NOD) mice have a number of features that distinguish them as bone marrow transplant recipients that must be understood prior to the clinical application of chimerism to induce tolerance. In the present studies, we characterized NOD HSCs, comparing their engraftment characteristics to HSCs from disease-resistant strains. Strikingly, NOD HSCs are significantly enhanced in engraftment potential compared with HSCs from disease-resistant donors. Unlike HSCs from disease-resistant strains, they do not require graft-facilitating cells to engraft in allogeneic recipients. Additionally, they exhibit a competitive advantage when coadministered with increasing numbers of syngeneic HSCs, produce significantly more spleen colony-forming units (CFU-Ss) in vivo in allogeneic recipients, and more granulocyte macrophage-colony-forming units (CFU-GMs) in vitro compared with HSCs from disease-resistant controls. NOD HSCs also exhibit significantly enhanced chemotaxis to a stromal cell-derived factor 1 (SDF-1) gradient and adhere significantly better on primary stroma. This enhanced engraftment potential maps to the insulin-dependent diabetes locus 9 (Idd9) locus, and as such the tumor necrosis factor (TNF) receptor family as well as ski/sno genes may be involved in the mechanism underlying the autonomy of NOD HSCs. These findings may have important implications to understand the evolution of autoimmune disease and impact on potential strategies for cure.

CD8(+), alphabeta-TCR(+), and gammadelta-TCR(+) cells in the recipient hematopoietic environment mediate resistance to engraftment of allogeneic donor bone marrow.

Historically, conditioning for engraftment of hematopoietic stem cells has been nonspecific. In the present study, we characterized which cells in the recipient hematopoietic microenvironment prevent allogeneic marrow engraftment. Mice defective in production of alphabeta-TCR(+), gammadelta-TCR(+), alphabeta- plus gammadelta-TCR(+), CD8(+), or CD4(+) cells were transplanted with MHC-disparate allogeneic bone marrow. Conditioning with 500 cGy total body irradiation (TBI) plus a single dose of cyclophosphamide (CyP) on day +2 establishes chimerism in normal recipients. When mice were conditioned with 300 cGy TBI plus a single dose of CyP on day +2, all engrafted, except wild-type controls and those defective in production of CD4(+) T cells. Mice lacking both alphabeta- and gammadelta-TCR(+) cells engrafted without conditioning, suggesting that both alphabeta- and gammadelta-TCR T cells in the host play critical and nonredundant roles in preventing engraftment of allogeneic bone marrow. CD8 knockout (KO) mice engrafted without TBI, but only if they received CyP on day +2 relative to the marrow infusion, showing that a CD8(-) cell was targeted by the CyP conditioning. The CD8(+) cell effector function is mechanistically different from that for conventional T cells, and independent of CD4(+) T helper cells because CD4 KO mice require substantially higher levels of conditioning than the other KO phenotypes. These results suggest that a number of cell populations with different mechanisms of action mediate resistance to engraftment of allogeneic marrow. Targeting of specific recipient cellular populations may permit conditioning approaches to allow mixed chimerism with minimal morbidity and could potentially avoid the requirement for myelotoxic agents altogether.