title: Prenatal passive transfer of maternal immunity in Asian elephants (Elephas maximus).
abstract: Asian (Elephas maximus) and African (Loxodonta africana) elephants exhibit characteristics of endotheliochorial placentation, which is common in carnivore species and is associated with modest maternal to fetal transplacental antibody transfer. However, it remains unknown whether the bulk of passive immune transfer in elephants is achieved prenatally or postnatally through ingestion of colostrum, as has been documented for horses, a species whose medical knowledgebase is often extrapolated for elephants. To address this issue, we took advantage of the fact that many zoo elephants are immunized with tetanus toxoid and/or rabies vaccines as part of their routine health care, allowing a comparison of serum antibody levels against these antigens between dams and neonates. Serum samples were collected from 3 newborn Asian elephant calves at birth (before ingestion of colostrum); 2-4 days after birth; and 2-3 months of age. The findings indicate that the newborns had anti-tetanus toxoid and anti-rabies titers that were equivalent to or higher than the titers of their dams from birth to approximately 3 months of age, suggesting that the majority of maternal-to-fetal transfer is transplacental and higher than expected based on the architecture of the Asian elephant placenta.
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Sally A
authors.initials: SA
authors.lastname: Nofs
authors.forename: Robert L
authors.initials: RL
authors.lastname: Atmar
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Keitel
authors.forename: Cathleen
authors.initials: C
authors.lastname: Hanlon
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Stanton
authors.forename: Jie
authors.initials: J
authors.lastname: Tan
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Flanagan
authors.forename: Lauren
authors.initials: L
authors.lastname: Howard
authors.forename: Paul D
authors.initials: PD
authors.lastname: Ling
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000907:Antibodies, Bacterial / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D004606:Elephants / Q000276:immunology*; D005260:Female; D007112:Immunity, Maternally-Acquired; D007114:Immunization; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011819:Rabies Vaccines / Q000276:immunology; D013745:Tetanus Toxoid / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000914:Antibodies, Viral; D011819:Rabies Vaccines; D013745:Tetanus Toxoid