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Mammalian models, such as murine, are used widely in pathophysiological studies because they have a high degree of similarity in body temperature, metabolism, and immune response with humans. However, non-vertebrate animal models have emerged as alternative models to study the host-pathogen interaction with minimal ethical concerns. Galleria mellonella is an alternative model that has proved useful in studying the interaction of the host with either bacteria or fungi, performing drug testing, and assessing the immunological response to different microorganisms. The G. mellonella immune response includes cellular and humoral components with structural and functional similarities to the immune effectors found in higher vertebrates, such as humans. An important humoral effector stimulated during infections is apolipophorin III (apoLp-III), an opsonin characterized by its lipid and carbohydrate-binding properties that participate in lipid transport, as well as immunomodulatory activity. Despite some parameters, such as the measurement of phenoloxidase activity, melanin production, hemocytes counting, and expression of antimicrobial peptides genes are already used to assess the G. mellonella immune response to pathogens with different virulence degrees, the apoLp-III quantification remains to be a parameter to assess the immune response in this invertebrate. Here, we propose an immunological tool based on an enzyme-linked immunosorbent assay that allows apoLp-III quantification in the hemolymph of larvae challenged with pathogenic agents. We tested the system with hemolymph coming from larvae infected with Escherichia coli, Candida albicans, Sporothrix schenckii, Sporothrix globosa, and Sporothrix brasiliensis. The results revealed significantly higher concentrations of apoLp-III when each microbial species was inoculated, in comparison with untouched larvae, or inoculated with phosphate-buffered saline. We also demonstrated that the apoLp-III levels correlated with the strains' virulence, which was already reported. To our knowledge, this is one of the first attempts to quantify apoLp-III, using a quick and easy-to-use serological technique.

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BACKGROUND: Opsonization, is the molecular mechanism by which target molecules promote interactions with phagocyte cell surface receptors to remove unwanted cells by induced phagocytosis. We designed an in vitro system to demonstrate that this procedure could be driven to eliminate adipocytes, using peptides mimicking regions of the complement protein C3b to promote opsonization and enhance phagocytosis. Two cell lines were used: (1) THP-1 monocytes differentiated to macrophages, expressing the C3b opsonin receptor CR1 in charge of the removal of unwanted coated complexes; (2) 3T3-L1 fibroblasts differentiated to adipocytes, expressing AQP7, to evaluate the potential of peptides to stimulate opsonization. (3) A co-culture of the two cell lines to demonstrate that phagocytosis could be driven to cell withdrawal with high efficiency and specificity. RESULTS: An array of peptides were designed and chemically synthesized p3691 and p3931 joined bound to the CR1 receptor activating phagocytosis (p < 0.033) while p3727 joined the AQP7 protein (p < 0.001) suggesting that opsonization of adipocytes could occur. In the co-culture system p3980 and p3981 increased lipid uptake to 91.2% and 89.0%, respectively, as an indicator of potential adipocyte phagocytosis. CONCLUSIONS: This in vitro model could help understand the receptor­ligand interaction in the withdrawal of unwanted macromolecules in vivo. The adipocyte-phagocytosis discussed may help to control obesity, since peptides of C3b stimulated the CR1 receptor, promoting opsonisation and phagocytosis of lipidcontaining structures, and recognition of AQP7 in the differentiated adipocytes, favored the phagocytic activity of macrophages, robustly supported by the co-culture strategy.

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Skin blisters of pemphigus foliaceus (PF) present concomitant deposition of autoantibodies and components of the complement system (CS), whose gene polymorphisms are associated with susceptibility to different autoimmune diseases. To investigate these in PF, we evaluated 992 single-nucleotide polymorphisms (SNPs) of 44 CS genes, genotyped through microarray hybridization in 229 PF patients and 194 controls. After excluding SNPs with minor allele frequency <1%, out of Hardy-Weinberg equilibrium in controls or in strong linkage disequilibrium (r2 ≥ 0.8), 201 SNPs remained for logistic regression. Polymorphisms of 11 genes were associated with PF. MASP1 encodes a crucial serine protease of the lectin pathway (rs13094773: OR = 0.5, p = 0.0316; rs850309: OR = 0.23, p = 0.03; rs3864098: OR = 1.53, p = 0.0383; rs698104: OR = 1.52, p = 0.0424; rs72549154: OR = 0.55, p = 0.0453). C9 (rs187875: OR = 1.46, p = 0.0189; rs700218: OR = 0.12, p = 0.0471) and C8A (rs11206934: OR = 4.02, p = 0.0323) encode proteins of the membrane attack complex (MAC) and C5AR1 (rs10404456: OR = 1.43, p = 0.0155), a potent anaphylatoxin-receptor. Two encode complement regulators: MAC-blocking CD59 (rs1047581: OR = 0.62, p = 0.0152) and alternative pathway-blocking CFH (rs34388368: OR = 2.57, p = 0.0195). One encodes opsonin: C3 (rs4807895: OR = 2.52, p = 0.0239), whereas four encode receptors for C3 fragments: CR1 (haplotype with rs6656401: OR = 1.37, p = 0.0382), CR2 (rs2182911: OR = 0.23, p = 0.0263), ITGAM (CR3, rs12928810: OR = 0.66, p = 0.0435), and ITGAX (CR4, rs11574637: OR = 0.63, p = 0.0056). Associations reinforced former findings, regarding differential gene expression, serum levels, C3, and MAC deposition on lesions. Deregulation of previously barely noticed processes, e.g., the lectin and alternative pathways and opsonization-mediated phagocytosis, also modulate PF susceptibility. The results open new crucial avenues for understanding disease etiology and may improve PF treatment through additional therapeutic targets.

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Se obtuvo suero antiglobulínico (Coombs) con el empleo de un inóculo consistente en un inmunocomplejo (IC) inmunoglobulina (Ig) humana-antiglobulina humana en carnero, como opsonina para favorecer la respuesta inmune. Se inmunizaron 18 carneros divididos en 3 grupos de 6: el primero y el segundo destinados a producir anti-IgG y anti-C3, respectivamente. Estos, a su vez, subdivididos en subgrupo A: en el que se empleó el método tradicional de obtención de suero de Coombs; y B: en el que se usó el adyuvante completo de Freud en la dosis inicial y el IC en la fase de mantenimiento. Al tercer grupo solo se le administró el IC puro (subgrupo A) y en una dilución 1:200 (subgrupo B). En los carneros de los subgrupos 1B y 2B se obtuvieron títulos más elevados de anti-IgG y anti-C3dg, que en los inmunizados por el método tradicional. La respuesta de anticuerpos en los animales que se inmunizaron con los IC (3A y 3B), fue más rápida y de mayor título que las obtenidas por el método tradicional (1A y 2A) o el método combinado (1B y 2B). La respuesta en el subgrupo 3B fue más prolongada, al parecer por un efecto de dosis(AU)

An antiglobulin serum (Coombs) was obtained using a consistent inoculums in a immunocomplex (IC) the human immunoglobulin (Ig)/human antiglobulin in the seep by example, the opsonin to favor the immune response. Eighteen sheeps were immunized divided into three groups of 6 each: The first and second aimed to produce anti-IgG and anti-C3, respectively. In turn, these were divided into the A subgroup: in which we used the traditional method of Coombs's serum obtaining and B group in which we used the Freud's whole adjuvant in initial dose and the IC in the maintaining phase. Third group received the pure IC (A subgroup) and at a dilution of 1:200 (B subgroup). In sheeps from the 1B and 2B subgroups it was possible to obtain higher titration of anti-IgG and anti-C3dg than those immunized by means of the traditional method. The antibody response in animals immunized with the ICs (3A and 3B) was faster and of higher titration than those obtained by traditional method (1A and 2A) or the combined method (1B and 2B). The response in the 3B subgroup was lengthier apparently by a dose effect(AU)

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Se obtuvo suero antiglobulínico (Coombs) con el empleo de un inóculo consistente en un inmunocomplejo (IC) inmunoglobulina (Ig) humana-antiglobulina humana en carnero, como opsonina para favorecer la respuesta inmune. Se inmunizaron 18 carneros divididos en 3 grupos de 6: el primero y el segundo destinados a producir anti-IgG y anti-C3, respectivamente. Estos, a su vez, subdivididos en subgrupo A: en el que se empleó el método tradicional de obtención de suero de Coombs; y B: en el que se usó el adyuvante completo de Freud en la dosis inicial y el IC en la fase de mantenimiento. Al tercer grupo solo se le administró el IC puro (subgrupo A) y en una dilución 1:200 (subgrupo B). En los carneros de los subgrupos 1B y 2B se obtuvieron títulos más elevados de anti-IgG y anti-C3dg, que en los inmunizados por el método tradicional. La respuesta de anticuerpos en los animales que se inmunizaron con los IC (3A y 3B), fue más rápida y de mayor título que las obtenidas por el método tradicional (1A y 2A) o el método combinado (1B y 2B). La respuesta en el subgrupo 3B fue más prolongada, al parecer por un efecto de dosis

An antiglobulin serum (Coombs) was obtained using a consistent inoculums in a immunocomplex (IC) the human immunoglobulin (Ig)/human antiglobulin in the seep by example, the opsonin to favor the immune response. Eighteen sheeps were immunized divided into three groups of 6 each: The first and second aimed to produce anti-IgG and anti-C3, respectively. In turn, these were divided into the A subgroup: in which we used the traditional method of Coombs's serum obtaining and B group in which we used the Freud's whole adjuvant in initial dose and the IC in the maintaining phase. Third group received the pure IC (A subgroup) and at a dilution of 1:200 (B subgroup). In sheeps from the 1B and 2B subgroups it was possible to obtain higher titration of anti-IgG and anti-C3dg than those immunized by means of the traditional method. The antibody response in animals immunized with the ICs (3A and 3B) was faster and of higher titration than those obtained by traditional method (1A and 2A) or the combined method (1B and 2B). The response in the 3B subgroup was lengthier apparently by a dose effect

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