Depletion of CD4 T lymphocytes at the time of infection with M. avium subsp. paratuberculosis does not accelerate disease progression.
A calf model was used to determine if the depletion of CD4 T cells prior to inoculation of Mycobacterium avium subsp. paratuberculosis (Map) would delay development of an immune response to Map and accelerate disease progression. Ileal cannulas were surgically implanted in 5 bull calves at 2 months of age. Two calves were depleted of CD4 T cells by intravenous injection of anti-bovine CD4 antibody administered 24h prior to inoculation with Map. The two CD4-depleted calves and one non-depleted calf were inoculated via ileal cannula with 1 × 10(8)cfu live Map every 3 days for a total of 4 inoculations. Two additional calves served as non-depleted and uninfected controls. Injection with the anti-CD4 mAb reduced the frequency of CD4 T cells from a pre-depletion average of 15% to less than 1% in PBMC at 24h. However, a consistent proliferative response dominated by CD4 T cells, developed in both treated and untreated calves over the course of the 6-month study period. Recovery of Map from serial biopsies obtained from the CD4-depleted and non-depleted calves after Map infection did not differ. In addition, CD4 depletion did not increase the level of Map shed in the feces over the non-depleted animal.
Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA 99164-7060, USA. aja@vetmed.wsu.edu
A J
AJ
Allen
J R
JR
Stabel
S
S
Robbe-Austerman
K T
KT
Park
M V
MV
Palmer
G M
GM
Barrington
K K
KK
Lahmers
Mary Jo
MJ
Hamilton
William C
WC
Davis
D000818:Animals; D000831:Animals, Newborn; D001706:Biopsy / Q000662:veterinary; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000276:immunology* / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D018450:Disease Progression; D005243:Feces / Q000382:microbiology; D005434:Flow Cytometry / Q000662:veterinary; D005767:Gastrointestinal Diseases / Q000097:blood / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D006651:Histocytochemistry / Q000662:veterinary; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D016927:Mycobacterium avium subsp. paratuberculosis / Q000235:genetics / Q000276:immunology*; D010283:Paratuberculosis / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000662:veterinary
D004269:DNA, Bacterial