Duplex nested-PCR for detection of small ruminant lentiviruses

Abstract Small ruminant lentiviruses (SRLV) have high genetic variability which results in different viral strains around the world. This create a challenge to design sensible primers for molecular diagnosis in different regions. This work proposes a protocol of duplex nested-PCR for the precise diagnosis of SRLV. The technique was designed and tested with the control strains CAEV Co and MVV 1514. Then, field strains were submitted to the same protocol of duplex nested-PCR. Blood samples of sheep and goats were tested with AGID and nested PCR with specific primers for pol, gag and LTR. The AGID results showed low detection capacity of positive animals, while the nested PCR demonstrated a greater capacity of virus detection. Results demonstrated that LTR-PCR was more efficient in detecting positive sheep samples, whereas gag-PCR allowed a good detection of samples of positive goats and positive sheep. In addition, pol-PCR was more efficient with goat samples than for sheep. Duplex nested PCR performed with standard virus samples and field strains demonstrated that the technique is more efficient for the detection of multiple pro-viral DNA sequences. This study demonstrated a successful duplex nested PCR assay allowing a more accurate diagnosis of SRLV.

Duplex nested-PCR for detection of small ruminant lentiviruses

Abstract Small ruminant lentiviruses (SRLV) have high genetic variability which results in different viral strains around the world. This create a challenge to design sensible primers for molecular diagnosis in different regions. This work proposes a protocol of duplex nested-PCR for the precise diagnosis of SRLV. The technique was designed and tested with the control strains CAEV Co and MVV 1514. Then, field strains were submitted to the same protocol of duplex nested-PCR. Blood samples of sheep and goats were tested with AGID and nested PCR with specific primers for pol, gag and LTR. The AGID results showed low detection capacity of positive animals, while the nested PCR demonstrated a greater capacity of virus detection. Results demonstrated that LTR-PCR was more efficient in detecting positive sheep samples, whereas gag-PCR allowed a good detection of samples of positive goats and positive sheep. In addition, pol-PCR was more efficient with goat samples than for sheep. Duplex nested PCR performed with standard virus samples and field strains demonstrated that the technique is more efficient for the detection of multiple pro-viral DNA sequences. This study demonstrated a successful duplex nested PCR assay allowing a more accurate diagnosis of SRLV.

Isolation, culture and characterization of multipotent mesenchymal stem cells from goat umbilical cord blood / Isolamento, cultura e caracterização de células tronco mesenquimais multipotentes provenientes do sangue do cordão umbilical caprino

Mesenchymal stem cells (MSC) reside in small numbers in many adult tissues and organs, and play an active role in the homeostasis of these sites. Goat derived multipotent MSC have been established from bone marrow, adipose tissues and amniotic fluid. Umbilical cord blood (UCB) is considered an important source of these cells. However, the MSC isolation from the goat UCB has not been demonstrated. Therefore, the aim of the present study was to isolate, culture and characterize goat umbilical cord blood derived mesenchymal stem cells. MSC were isolated from UCB by Ficoll-Paque density centrifugation and cultured in DMEM supplemented with 10% or 20% FBS. FACS analysis was performed and induction lineage differentiation was made to characterize these cells. They exhibited two different populations in flow cytometry, and revealed the positive expression of CD90, CD44 and CD105, but negative staining for CD34 in larger cells, and positive stained for CD90 and CD105, but negative for CD44 and CD34 in the smaller cells. MSC from goat UCB showed capability to differentiate into chondrocytes and osteoblasts when incubated with specific differentiation medium. Present study established that goat mesenchymal stem cells can be derived successfully from umbilical cord blood.(AU)

As células tronco mesenquimais (MSC) residem em pequenas quantidades em muitos tecidos e órgãos adultos, desempenhando um papel ativo na homeostase destes locais. O isolamento de MSC já foi demonstrado em amostras de medula óssea, tecido adiposo e fluido amniótico de cabras. O sangue de cordão umbilical é considerado uma fonte importante desse tipo de células. No entanto, até o presente momento, não foi demonstrado o isolamento de MSC provenientes do sangue de cordão umbilical de cabras. Dessa forma, o objetivo do presente estudo foi isolar, cultivar e caracterizar células tronco mesenquimais provenientes do sangue do cordão umbilical caprino. As MSC foram isoladas utilizando o gradiente de densidade Ficoll-Paque e cultivadas em DMEM suplementado com 10% ou 20% de FBS. A caracterização desse tipo celular foi realizada através de análise por citometria de fluxo e diferenciação em linhagens celulares mesodermais. A analise no citômetro de fluxo demonstrou a presença de duas populações distintas, um grupo com células maiores e outro com células menores; observando expressão positiva de CD90, CD44 e CD105, e negativa para CD34 nas células maiores; enquanto que as menores foram positivas para CD90 e CD105, mas negativas para CD44 e CD34. As células isoladas demonstraram capacidade de se diferenciar em condrócitos e osteoblastos quando incubadas com meio de diferenciação específico. O presente estudo demonstrou que células tronco mesenquimais podem ser obtidas com sucesso do sangue do cordão umbilical caprino.(AU)

Goat umbilical cord cells are permissive to small ruminant lentivirus infection in vitro

Abstract Small ruminant lentiviruses isolated from peripheral blood leukocytes and target organs can be propagated in vitro in fibroblasts derived from goat synovial membrane cells. These cells are obtained from tissues collected from embryos or fetuses and are necessary for the establishment of the fibroblast primary culture. A new alternative type of host cells, derived from goat umbilical cord, was isolated and characterized phenotypically with its main purpose being to obtain cell monolayers that could be used for the diagnosis and isolation of small ruminant lentiviruses in cell culture. To accomplish this goal, cells were isolated from umbilical cords; characterized phenotypically by flow cytometry analysis; differentiate into osteogenic, chondrogenic and adipogenic lineage; and submitted to viral challenge. The proliferation of goat umbilical cord cells was fast and cell monolayers formed after 15 days. These cells exhibited morphology, immunophenotype, growth characteristics, and lineage differentiation potential similar to mesenchymal stem cells of other origins. The goat umbilical cord derived cells stained positive for vimentin and CD90, but negative for cytokeratin, CD34 and CD105 markers. Syncytia and cell lysis were observed in cell monolayers infected by CAEV-Cork and MVV-K1514, showing that the cells are permissive to small ruminant lentivirus infection in vitro. These data demonstrate the proliferative competence of cells derived from goat umbilical cords and provide a sound basis for future research to standardize this cell lineage.