No abstract

The environmental factors that contribute to the development of autoimmune diseases are largely unknown. Endemic pemphigus foliaceus in humans, known as Fogo Selvagem (FS) in Brazil, is mediated by pathogenic IgG4 autoantibodies against desmoglein1 (Dsg1). Clusters of FS overlap with those of leishmaniasis, a disease transmitted by sand fly (Lutzomyia longipalpis) bites. In this study we show that salivary antigens from the sand fly, and specifically the LJM11 salivary protein, are recognized by FS antibodies. Anti-Dsg1 monoclonal autoantibodies derived from FS patients also cross-react with LJM11. Mice immunized with LJM11 generate anti-Dsg1 antibodies. Thus, insect bites may deliver salivary antigens that initiate a cross-reactive IgG4 antibody response in genetically susceptible individuals and lead to subsequent FS. Our findings establish a clear relationship between an environmental, non-infectious antigen and the development of potentially pathogenic autoantibodies in an autoimmune disease.

Building bridges between environmental and political agendas is essential nowadays in face of the increasing human pressure on natural environments, including wetlands. Wetlands provide critical ecosystem services for humanity and can generate a considerable direct or indirect income to the local communities. To meet many of the sustainable development goals, we need to move our trajectory from the current environmental destructive development to a wiser wetland use. The current article contain a proposed agenda for the Pantanal aiming the improvement of public policy for conservation in the Pantanal, one of the largest, most diverse, and continuous inland wetland in the world. We suggest and discuss a list of 11 essential interfaces between science, policy, and development in region linked to the proposed agenda. We believe that a functional science network can booster the collaborative capability to generate creative ideas and solutions to address the big challenges faced by the Pantanal wetland.

The goal of this study was to examine seasonal frugivory by two sympatric peccary species (Tayassu pecari and T. tajacu) in a small (2178 ha), Atlantic Forest fragment on the inland plateau region of São Paulo State, Brazil. Fruit availability was determined with systematic ground surveys conducted over a 5‐yr period. Examining fruit availability trends for dry and wet seasons, we found that species diversity was greater in the wet season, but the total number and dry mass of fruits were higher in the dry season. Fruit abundance in the dry season was due to one palm, ‘jeriva’ (Syagrus romanzoffiana), which could be considered a keystone species at Caetetus Ecological Station as it also supported a diverse array of mammals, birds, reptiles, and insects. White‐lipped peccaries were the only ungulates that ate palmito fruits (Euterpe edulis) at Caetetus. They consumed ripe and unripe fruits and predated the seeds by chewing the pulp and seed. This occurred primarily during the dry season and was associated with a seasonal range shift and a preference for palmito habitat by the white‐lipped peccaries. The dominance of fruits in peccary diets (80% fruit items in scat) has management implications for other plateau forest fragments. Forest fragments with diminished fruit abundance or diversity, or lacking key species such as S. romanzoffiana or E. edulis, will not support the energetic requirements of the characteristically large and highly mobile white‐lipped peccary populations.

An ongoing sero-epidemiological study of the Terena reservation of Limao Verde, known to have a high prevalence and incidence of FS, has revealed important information about this autoimmune disease. During surveillance of this population of approximately 1,200, which began in 1994, we documented 43 FS cases and studied the transition from the normal state to the disease state in several of these individuals. Furthermore, we established that FS patients as well as a large number of normal individuals on the reservation possess anti-dsg1 autoantibodies. The following interesting observations were made: (1) the ectodomain of dsg1 contains epitopes recognized by both autoantibodies and T cells from FS patients; (2) pathogenic anti-dsg1 autoantibodies in FS belong to the IgG4 subclass; (3) nonpathogenic anti-dsg1 autoantibodies of the IgG1 subclass were detected in normal individuals from Limao Verde and in patients in the preclinical stage of the disease; (4) anti-dsg1 autoantibodies from normal individuals and patients in the preclinical stage of FS recognize the EC5 domain of dsg1, whereas pathogenic anti-dsg1 autoantibodies bind the EC1/EC2 domains; (5) houses of FS patients are rustic, with thatched roofs and walls and dirt floors; (6) there was a high frequency of hematophagous insects (bedbugs and kissing bugs) in the houses of FS patients; (7) previous studies revealed that the predominant black fly on this reservation belongs to the species Simunlium nigrimanum. These findings suggest that the environmental antigen(s) triggering the autoimmune response in FS may be linked to exposure to hematophagous insects.