Frequency and phenotype of EHV-1 specific, IFN-gamma synthesising lymphocytes in ponies: the effects of age, pregnancy and infection.
Equine herpesvirus-1 (EHV-1) infects horses, causing acute respiratory disease, neurological signs, and is also a leading cause of abortion. Protection from EHV-1 infection and disease depends on both humoral (virus neutralising antibody) and cellular (mainly cytotoxic T lymphocytes, CTL) immune responses. CTL activity after EHV-1 infection has been extensively investigated and is closely associated with an alternative measure of cell mediated immunity (CMI), interferon-gamma (IFN-gamma) synthesis. This study investigates EHV-1-specific IFN-gamma synthesising cells in potentially immunocompromised horses; foals, pregnant mares and aged animals, after field or experimental infection with EHV-1. In foals and pregnant mares, the kinetics after experimental infection were similar and the phenotype of IFN-gamma+ synthesising cells after EHV-1 stimulation was mainly CD8alpha+. In contrast, in samples collected from primed healthy ponies exposed to EHV-1 several months previously or in old ponies (28 years old), the majority of EHV-1-specific IFN-gamma+ lymphocytes expressed a CD5+, CD8alpha- phenotype. This study highlights the complexity of the relationship between EHV-1, a common pathogen in horses, and the virus-specific cellular immune response as measured using IFN-gamma synthesis.
Paillot
Romain
R
Animal Health Trust, Centre for Preventive Medicine, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK. romain.paillot@aht.org.uk
Daly
Janet M
JM
Luce
Richard
R
Montesso
Fernando
F
Davis-Poynter
Nick
N
Hannant
Duncan
D
Kydd
Julia H
JH
D000367:Age Factors; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D006566:Herpesviridae Infections / Q000276:immunology / Q000662:veterinary*; D004861:Herpesvirus 1, Equid / Q000276:immunology*; D006734:Horse Diseases / Q000276:immunology*; D006736:Horses; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis*; D007694:Killer Cells, Natural / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000276:immunology*
D007371:Interferon-gamma