The aim of this study was to compare the physicochemical parameters of milk samples of five different species: cow, goat, donkey, camel and human. Also the analysis of whey protein profile in different milk samples was performed by anion-exchange fast protein liquid chromatography (FPLC) while polyacrylamide gel electrophoresis was used to identify a single fraction. Camel milk was the most acid (pH 6.460±0.005) and the richest in total proteins (3.41±0.31 %) and ash (0.750±0.102 %), whereas donkey milk had a neutral pH (7.03±0.02) and characterised by low proteins (1.12±0.40 %) and fat (0.97±0.03 %) content, being very close to human milk. Proteomic analysis of cow, goat, donkey, camel and human milk highlighted significant interspecies differences. Camel milk was similar to human milk in lacking of β-lactoglobulin and richness of α-lactalbumin. The knowledge gained from the proteomic comparison of the milk samples analysed within this study might be of relevance, both, in terms of identifying sources of hypoallergenic alternatives to bovine milk and detection of adulteration of milk samples and products.

Ovarian cancer has the highest mortality rate among gynecologic malignancies. The monoclonal antibody 12G4 specifically recognizes the human Müllerian inhibiting substance type II receptor (MISRII) that is strongly expressed in human granulosa cell tumors (GCT) and in the majority of human epithelial ovarian cancers (EOC). To determine whether MISRII represents an attractive target for antibody-based tumor therapy, we first confirmed by immunohistochemistry with 12G4 its expression in all tested GCT samples (4/4) and all, but one, EOC human tissue specimens (13/14). We then demonstrated in vitro the internalization of 12G4 in MISRII(high)COV434 cells after binding to MISRII and its ability to increase the apoptosis rate (FACS, DNA fragmentation) in MISRII(high)COV434 (GCT) and MISRII(medium)NIH-OVCAR-3 (EOC) cells that express different levels of MISRII. A standard (51)Cr release assay showed that 12G4 mediates antibody-dependent cell-meditated cytotoxicity. Finally, in vivo assessment of 12G4 anti-tumor effects showed a significant reduction of tumor growth and an increase of the median survival time in mice xenografted with MISRII(high)COV434 or MISRII(medium)NIH-OVCAR-3 cells and treated with 12G4 in comparison to controls treated with an irrelevant antibody. Altogether, our data indicate that MISRII is a new promising target for the control of ovarian GCTs and EOCs. A humanized version of the 12G4 antibody, named 3C23K, is in development for the targeted therapy of MISRII-positive gynecologic cancers.

Impairment of the omp25 gene in Brucella spp. leads to attenuated strains and confers protection to the host. Omp25 and Omp31, whose functions remain unknown, were the first characterized members of group 3 outer membrane proteins (Omps) (25 to 34 kDa). Recently, genomic and proteomic approaches identified five new putative members of this family, some of which are produced in B. melitensis or B. abortus. In the present study, using protein microsequencing, we identified new members of group 3 Omps proteins produced in B. suis. Since several monoclonal antibodies (MAbs) against Omp25 cross-reacted with other members of group 3 Omps, we also performed Western immunoblotting to compare wild-type B. suis with mutants systematically having B. suis omp25-related genes knocked out. We demonstrate the production of three paralogs of Omp31 and/or Omp25 in B. suis, and the existence of a common site of signal peptide cleavage (AXAAD), which is very similar to that present in the five homologous Omps of Bartonella quintana. The seven group 3 Omps were classified in four-subgroups on the basis of percentage amino acid sequence identities: Omp25 alone, the Omp25b-Omp25c-Omp25d cluster, the Omp31/31b subgroup, and the less related Omp22 protein (also called Omp3b). Together with previous data, our results demonstrate that all new members of group 3 Omps are produced in B. suis or in other Brucella species and we propose a nomenclature that integrates all of these proteins to facilitate the understanding of future Brucella interspecies study results.Brucellae are small, nonmotile, gram-negative coccobacilli that are able to infect a broad range of wildlife and domestic mammals. They remain a major zoonotic disease source affecting humans worldwide and are also a focus of concern as potential biological warfare agents (20). Although BrucelIa spp. are not particularly host specific, three major (B. abortus, B. melitensis, and B. suis) and minor (B. canis, B. ovis, and B. neotomae) species each have distinct host preferences and pathogenicities for humans (29). Malta fever (also known as Mediterranean, Gibraltar, or undulant fever) and porcine brucellosis-caused by B. melitensis and B. suis infection of humans, respectively-are usually by far more clinically apparent than Bang's disease (B. abortus infection), whereas among the remaining species only B. canis causes anecdotal mild infections in humans (10).The Brucella outer membrane was investigated to seek immunogenic and protective antigens for potential diagnostic and vaccine applications. The major outer membrane proteins (Omps) of Brucella spp. were thoroughly studied in this regard.

Anti-Müllerian hormone (AMH) [also called Müllerian inhibiting substance (MIS)] is a member of the transforming growth factor-beta family. AMH and its type II receptor (AMHR-II) are involved in the regression of the Müllerian ducts in the male embryo, and in gonadal functions in the adult. AMH is also known to be a marker of granulosa and Sertoli cell tumours. We selected a high-affinity monoclonal antibody, mAb 12G4, specific for human AMHR-II (hAMHR-II), by FACS analysis, Western blotting and immunohistochemical staining of a hAMHR-II-transfected CHO (Chinese hamster ovary) cell line, normal adult testicular tissue and granulosa cell tumours. Using peptide array screening, we identified the binding sequences of mAb 12G4 and AMH on the receptor. Identification of Asp53 and Ala55 as critical residues in the DRAQVEM minimal epitopic sequence of mAb 12G4 definitively accounted for the lack of cross-reactivity with the murine receptor, in which there is a glycine residue in place of an aspartic acid residue. In a structural model, the AMH-binding interface was mapped to the concave side of hAMHR-II, whereas the mAb 12G4-binding site was located on the convex side. mAb 12G4, the first mAb to be raised against hAMHR-II, therefore has unique properties that could make it a valuable tool for the immunotargeting of tumours expressing this receptor.

The survival and replication of Brucella in macrophages is initially triggered by a low intraphagosomal pH. In order to identify proteins released by Brucella during this early acidification step, we analyzed Brucella suis conditioned medium at various pH levels. No significant proteins were released at pH 4.0 in minimal medium or citrate buffer, whereas in acetate buffer, B. suis released a substantial amount of soluble proteins. Comparison of 13 N-terminal amino acid sequences determined by Edman degradation with their corresponding genomic sequences revealed that all of these proteins possessed a signal peptide indicative of their periplasmic location. Ten proteins are putative substrate binding proteins, including a homologue of the nopaline binding protein of Agrobacterium tumefaciens. The absence of this homologue in Brucella melitensis was due to the deletion of a 7.7-kb DNA fragment in its genome. We also characterized for the first time a hypothetical 9.8-kDa basic protein composed of five amino acid repeats. In B. suis, this protein contained 9 repeats, while 12 were present in the B. melitensis orthologue. B. suis in acetate buffer depended on neither the virB type IV secretory system nor the omp31 gene product. However, the integrity of the omp25 gene was required for release at acidic pH, while the absence of omp25b or omp25c displayed smaller effects. Together, these results suggest that Omp25 is involved in the membrane permeability of Brucella in acidic medium.Bacteria of the genus Brucella are gram-negative facultative intracellular pathogens of various wild and domestic mammals and are able to cause severe zoonotic infections in humans. Traditionally, three major species are distinguished by their predilections for certain animal hosts: Brucella abortus for cattle, Brucella melitensis for caprines, and Brucella suis for hogs. Whereas B. abortus is the livestock pathogen with the greatest economic impact, B. melitensis and B. suis account for most clinical cases in humans (1, 2, 11).To evade host defenses, Brucella can inhibit neutrophil degranulation and block tumor necrosis factor (TNF) production by macrophages. It has been shown that membrane integrity, in terms of both smooth lipopolysaccharide and outer membrane proteins, is required for such virulent behavior. Furthermore, studies using transposon or signature-tagged mutagenesis have unraveled, with respect to Brucella virulence, the crucial role of an operon homologous to the virB operon of Agrobacterium tumefaciens encoding a type IV secretion system (16, 21, 28). The virulence regulon of A. tumefaciens is triggered in response to chemical signals released at the plant wound site, such as acetosyringone and low pH. Type IV secretion system production is potentiated by monosaccharides (galactose and arabinose) through binding to the periplasmic multiple sugar binding protein ChvE, as well as by low pH (6). However, it was found that under neutral conditions, this secretory system is already produced in B. melitensis or B. abortus, while ...

In this paper, we focus on the camelid nanobodies as a revolutionary therapy that can guide efforts to discover new drugs for Coronavirus disease . The small size property makes nanobodies capable of penetrating efficiently into tissues and recognizing cryptic antigens. Strong antigen affinity and stability in the gastrointestinal tract allow them to be used via oral administration. In fact, the use of nanobodies as inhalant can be directly delivered to the target organ, conferring high pulmonary drug concentrations and low systemic drug concentrations and minimal systemic side effects. For that, nanobodies are referred as a class of next-generation antibodies. Nanobodies permit the construction of multivalent formats that may achieve ultra-high neutralization potency and then may prevent mutational escape and can neutralize a wide range of SARS-CoV-2 variants. Due to their distinctive characteristics, nanobodies can be of great use in the development of promising treatment or preventive strategies against SARS-CoV-2 infection. In this review, the state-of-the-art of camel nanobodies design strategies against the virus including SARS-CoV-2 are critically summarized. The application of general nanotechnology was also discussed to mitigate and control emerging SARS-CoV-2 infection.

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In many mammalian species, newborns are agammaglobulinemic; thus, colostrum and milk are the main sources of early protective antibodies. These antibodies are produced in the mother's serum and transferred to mammalian glands a few days before parturition. Here, we have studied the transfer of immunity from a she-camel immunized with human serum albumin (HSA) to her calf via colostrum and milk. Our results show that HSA-specific antibodies are produced in the mother's serum and are subsequently transferred to her colostrum. These specific antibodies are then transferred by suckling to the calf. The calf serum did not contain HSA-reactive antibodies at parturition and before the first feed, after suckling, a rise in reactivity was observed peaking at 24 h postpartum. The involvement of heavy chain antibodies (HCAbs) in the process of immunity transfer was also examined, and it was found that they were also transferred from the colostrum to the calf serum like conventional antibodies.