Exosomes secreted by tumor cells are a good source of cellular components that stimulate the immune response, such as alarmins (mRNA, tetraspanins (CD9, CD63, CD81), heat-shock proteins, major histocompatibility complex class I molecules) and tumor-associated antigens. These properties permit to pulsed dendritic cells in the immunotherapy for many cancers types. The aim of this study was to demonstrate the use of exosomes derived from canine transmissible venereal tumor (CTVT) as an antigen to pulsed dendritic cells and its administration in dogs with CTVT as treatment against this disease. From primary culture of CTVT cells the exosomes were isolated and characterized by scanning electron microscopy assay, dot blot and protein quantification. The monocytes of each patient were differentiated to dendritic cells (DC) and pulsed with CTVT exosomes (CTVTE). Phagocytosis, tumor size, populations of lymphocytes and IFN-γ levels were evaluated. The CTVTE showed a size around 90 nm. CD81, CD63, CD9 and Hsp70 were expressed. Monocytes showed an expression of 85.71% for CD14⁺, 12.3% for CD80⁺, 0.1% for CD83⁺ and 0.8% for DLA-II. In DC 5.1% for CD14⁺, 86.7% for CD80⁺, 90.1% for CD83⁺ and 92.6% for DLA-II and a phagocytosis of 63% was obtained by FITC-Dextran test. No side effects were observed in the experimental groups with our therapy. Tumor regression was of 100% at the seventh week, as well as an increase in the level of IFN-γ (142 pg/ml), and CD4⁺ (28%) and CD8⁺ (34%) cell percentage. These results have shown that DC pulsed with tumor exosomes induce regression of the TVT in dogs.

Aflatoxins can cause intoxication and poisoning in animals and humans. Among these molecules, aflatoxin B₁ (AFB₁) is the most dangerous because of its carcinogenic and mutagenic properties. To mitigate these effects, clay adsorbents are commonly included in the diet of animals to adsorb the carcinogens and prevent their absorption in the gastrointestinal tract. In this study, four clays, three smectites (C-1, C-2, and C-3), and one zeolite (C-4), were compared as adsorbents of AFB₁ and trace inorganic nutrients using an in vitro gastrointestinal model for poultry. Characterization of the clays using Fourier transform infrared spectroscopy revealed characteristic bands of smectites in C-1, C-2, and C-3 (stretching vibrations of Si-O, Al-O-Si, and Si-O-Si). The C-4 presented bands related to the bending vibration of structural units (Si-O-Si and Al-O-Si). X-ray diffraction analysis showed that C-1 is a montmorillonite, C-2 is a beidellite, C-3 is a beidellite-Ca-montmorillonite, and C-4 is a clinoptilolite. The elemental compositions of the clays showed alumina, silica, iron, calcium, and sodium contents. The cation exchange capacity was higher in C-3 clay (60.2 cmol(+)/kg) in contrast with the other clays. The AFB₁ adsorption of C-1 was the highest (99.5%; p ˂ 0.001), followed by C-2 (92.02%). However, all the clays also sequestered trace inorganic nutrients (Fe, Mn, Zn, and Se). Both smectites, montmorillonite and beidellite, were the most suitable for use as adsorbents of AFB₁.

Blood samples were obtained from 16 high-risk heifers; eight were newly arrived from a 40 h road trip (0 days post-arrival (DPA)), whereas the other eight heifers had been in the feedlot at 25 DPA. Both groups were transported from the southeast tropical region of Mexico to a feedlot in the northeast and were sampled on the same day. The complete blood count, blood chemistry, and cytokine gene expression were analyzed. Gene expression was analyzed using specific primers to amplify and quantify the cDNA reverse transcribed from the mRNA transcripts for tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-2. Higher values for hematocrit (p = 0.029), hemoglobin (p = 0.002), eosinophils (0.029), albumin (p = 0.014), alanine aminotransferase (p = 0.004), bilirubin (p = 0.003), cholesterol (p = 0.014), and cortisol (p = 0.051) were observed in the 0 DPA group than the 25 DPA group. In the electrophoresis of TNF-α amplification products, two non-specific bands were observed in the 0 DPA group. These bands were sequenced, and BLAST analysis suggested that they corresponded to bovine lymphotoxin and have not been reported previously related to stress. The TNF-α expression level was higher (p = 0.001) in the 25 DPA group than the 0 DPA group according to the semi-quantitative expression analysis. This may indicate a persistent inflammatory process that could be related to trauma and disease, which can negatively impact their subsequent health and growth performance. In conclusion, homeostatic disruption was apparent in the 0 DPA heifers, which showed higher cortisol and reductions in TNF-α levels and stress-induced bovine lymphotoxin (SIBL) co-expression.

Introduction: Canine transmissible venereal tumour (CTVT) is a sexually transmitted tumour affecting dogs worldwide, imposing a financial burden on dog owners. A stable culture cell line in continuous passages for >18 months has only been achieved once. The present study investigated a stable CTVT cell line isolated from a bitch and its potential as a vaccine. Material and Methods: A biopsy from a 2-year-old mongrel bitch with CTVT was obtained for histopathological confirmation and isolation of tumour cells. The isolated cells were cultured to passage 55 and characterised by flow cytometry, with karyotyping by GTG-banding and by PCR detection of myc S-2 and LINE AS1. The isolated CTVT cell line was also used as a preventive vaccine in a canine model. Results: Histopathological analysis of the isolated tumour cells revealed typical CTVT characteristics. Constant proliferation and stable morphological characteristics were observed during culture. Phenotypic analysis determined the expression of HLA-DR ⁺ , CD5.1 ⁺ , CD14 ⁺ , CD45 ⁺ , CD83 ⁺ , CD163 ⁺ , and Ly-6G-Ly-6C ⁺ . GTG-banding revealed a mean of 57 chromosomes in the karyotype with several complex chromosomal rearrangements. LINE-c-myc insertion in the isolated CTVT cell line at 550 bp was not detected. However, a 340-bp band was amplified. Isolated CTVT cell line inoculation at a concentration of 1×10 ⁸ did not induce tumour growth in bitches, nor did a challenge with primary CTVT cells. Conclusion: The present study successfully identified and isolated a stable CTVT cell line that may be useful in CTVT prevention.

The gut microbiota is involved in the productivity of beef cattle, but the impact of different analysis strategies on microbial composition is unclear. Ruminal samples were obtained from Beefmaster calves (n = 10) at both extremes of residual feed intake (RFI) values (5 with the lowest and 5 with the highest RFI) from two consecutive days. Samples were processed using two different DNA extraction methods. The V3 and V4 regions of the 16S rRNA gene were amplified using PCR and sequenced with a MiSeq instrument (Illumina). We analyzed 1.6 million 16S sequences from all 40 samples (10 calves, 2 time points, and 2 extraction methods). The abundance of most microbes was significantly different between DNA extraction methods but not between high-efficiency (LRFI) and low-efficiency (HRFI) animals. Exceptions include the genus Succiniclasticum (lower in LRFI, p = 0.0011), and others. Diversity measures and functional predictions were also mostly affected by DNA extraction methods, but some pathways showed significant differences between RFI levels (e.g., methylglyoxal degradation, higher in LRFI, p = 0.006). The results suggest that the abundance of some ruminal microbes is associated with feed efficiency and serves as a cautionary tale for the interpretation of results obtained with a single DNA extraction method.