Resumo: A geleia de Wharton do cordão umbilical (GWCU) de mamíferos é uma fonte promissora de células multipotentes, sendo vantajosa por aspectos éticos, facilidade de coleta e não causar teratomas em ensaios pré-clínicos. Em ovinos, células multipotentes já foram isoladas de vários tecidos, no entanto, não existem relatos do isolamento a partir do cordão umbilical nesta espécie. O objetivo do presente estudo foi investigar o melhor meio para o transporte do cordão umbilical, isolar e manter as células da GWCU ovino em diferentes meios e comparar a proliferação e o potencial de diferenciação mesodermal in vitro. Oito cordões umbilicais foram obtidos, por ocasião do parto natural, seccionados e transportados em seis diferentes meios que consistiram em MEM, DMEM baixa glicose, M199, RPMI 1640, PBS e soro fisiológico. Para cada meio de transporte foram utilizados quatro meios de cultivo, sendo o tecido explantado em placas de 24 poços e cultivados em MEM, DMEM baixa glicose, M199 e RPMI 1640, todos com 10% SFB. Todo o experimento foi realizado em baixa passagem (P2) investigando viabilidade pelo MTT por quatro dias além da indução à diferenciação adipogênica, condrogênica e osteogênica in vitro. O meio de transporte mais efetivo (P<0,10) foi o DMEM baixa glicose. Não houve contaminações bacterianas ou fúngicas decorrentes da coleta. Células oriundas da geleia de Wharton do cordão umbilical ovino colhido por ocasião do parto natural possuem morfologia fibroblastóide e capacidade de diferenciação in vitro nas linhagens adipogênica, condrogênica e osteogênica. Os ensaios de MTT e diferenciação in vitro, revelaram que o meio de cultura celular modula o comportamento destas células, sendo um fator importante tanto para a proliferação como para a manutenção da multipotência, destacando o DMEM baixa glicose como o meio mais adequado para o transporte e isolamento de células da geleia de Wharton do cordão umbilical ovino.

Abstract: The mammalian Wharton's jelly of umbilical cord (WJUC) is a promising source of multipotent cells, providing advantages due to ethical implications, ease of collection and the absence of teratomas in pre-clinical trials. Ovine multipotent cells have already been isolated from various tissues, however there are no reports using umbilical cords in this species. This study aimed to investigate the best medium to transport the umbilical cord, to isolate and maintain ovine WJUC cells and to compare in vitro growth and mesodermal differentiation potential. Eight ovine umbilical cords were obtained during parturition, sectioned and transported in six different media: MEM, low glucose DMEM, M199, RPMI 1640, PBS and saline. For each transportation medium, four culture media were used and the tissue was explanted in 24-well plates and cultured in MEM, low glucose DMEM, M199 and RPMI 1640, all with 10% FBS. Every experiment was conducted with low-passage (P2), investigating MTT viability during four days and adipogenic, chondrogenic and osteogenesis differentiation was induced in vitro. The most effective transport medium (p<0.1) was low glucose DMEM. There was no bacterial or fungal contamination from collection. Cells from Wharton's jelly of ovine umbilical cords collected at natural birth possess fibroblastic morphology and the capacity for in vitro differentiation into adipogenic, chondrogenic and osteogenic cell lines. MTT tests and in vitro differentiation experiments revealed that cell culture medium modulates the behavior of cells and is an important factor for proliferation and maintenance of multipotency. Low glucose DMEM was the most suitable medium for the isolation of cells from Wharton's jelly of ovine umbilical cord.

This study was conducted in order to evaluate the transmission of caprine lentivirus to sheep using different experimental groups. The first one (colostrum group) was formed by nine lambs receiving colostrum from goats positive for small ruminant lentiviruses (SRLV). The second group (milk group) was established by nine lambs that received milk of these goats. Third was a control group, consisting of lambs that suckled colostrum and milk of negative mothers. Another experimental group (contact group) was formed by eight adult sheep, confined with two naturally infected goats. The groups were monitored by immunoblotting (IB), enzyme-linked immunosorbent assay (ELISA), agar gel immunodiffusion (AGID) and nested polymerase chain reaction (nPCR). All lambs that suckled colostrum and milk of infected goats and six sheep of the contact group had positive results in the nPCR, although seroconversion was detected only in three of the exposed animals, with no clinical lentiviruses manifestation, in 720 days of observation. There was a close relationship between viral sequences obtained from infected animals and the prototype CAEV-Cork. Thus, it was concluded that SRLV can be transmitted from goats to sheep, however, the degree of adaptation of the virus strain to the host species probably interferes with the infection persistence and seroconversion rate.