PMID- 10769076
OWN - NLM
STAT- MEDLINE
DCOM- 20000609
LR  - 20031114
IS  - 0022-1317 (Print)
IS  - 0022-1317 (Linking)
VI  - 81
IP  - Pt 5
DP  - 2000 May
TI  - Effect of cellular changes and onset of humoral immunity on the replication of 
      porcine reproductive and respiratory syndrome virus in the lungs of pigs.
PG  - 1327-34
AB  - Twenty-two 4- to 5-week-old gnotobiotic pigs were intranasally inoculated with 
      10(6.0) TCID(50) of porcine reproductive and respiratory syndrome virus (PRRSV) 
      (Lelystad) and euthanized at different time intervals post-inoculation (p.i.). 
      Bronchoalveolar lavage (BAL) cell populations were characterized, together with 
      the pattern of virus replication and appearance of antibodies in the lungs. Total 
      BAL cell numbers increased from 140x10(6) at 5 days p.i. to 948x10(6) at 25 days 
      p.i. and remained at high levels until the end of the experiment. The number of 
      monocytes/macrophages, as identified by monoclonal antibodies 74-22-15 and 41D3, 
      increased two- to fivefold between 9 and 52 days p.i. with a maximum at 25 days 
      p.i. Flow cytometry showed that the population of differentiated macrophages was 
      reduced between 9 and 20 days p.i. and that between the same time interval, both 
      74-22-15-positive and 41D3-negative cells, presumably monocytes, and 74-22-15- 
      and 41D3-double negative cells, presumably non-phagocytes, entered the alveolar 
      spaces. Virus replication was highest at 7 to 9 days p.i., decreased slowly 
      thereafter and was detected until 40 days p.i. Anti-PRRSV antibodies were 
      detected starting at 9 days p.i. but neutralizing antibodies were only 
      demonstrated in one pig euthanized at 35 days and another at 52 days p.i. The 
      decrease of virus replication in the lungs from 9 days p.i. can be attributed to 
      (i) shortage of susceptible differentiated macrophages, (ii) lack of 
      susceptibility of the newly infiltrated monocytes and (iii) appearance of 
      anti-PRRSV antibodies in the lungs. Neutralizing antibodies may contribute to the 
      clearance of PRRSV from the lungs.
FAU - Labarque, G G
AU  - Labarque GG
AD  - Laboratory of Virology, Faculty of Veterinary Medicine, University of Gent, 
      Salisburylaan 133, B-9820 Merelbeke, Belgium.
FAU - Nauwynck, H J
AU  - Nauwynck HJ
FAU - Van Reeth, K
AU  - Van Reeth K
FAU - Pensaert, M B
AU  - Pensaert MB
LA  - eng
PT  - Journal Article
PL  - England
TA  - J Gen Virol
JT  - The Journal of general virology
JID - 0077340
RN  - 0 (Antibodies, Viral)
SB  - IM
MH  - Animals
MH  - Antibodies, Viral/*analysis/blood
MH  - Bronchoalveolar Lavage Fluid/cytology/*immunology/virology
MH  - Germ-Free Life
MH  - Lung/immunology/*virology
MH  - Neutralization Tests
MH  - Porcine Reproductive and Respiratory Syndrome/immunology/pathology/*virology
MH  - Porcine respiratory and reproductive syndrome virus/*immunology/isolation & 
      purification/*physiology
MH  - Swine
MH  - Virus Replication
EDAT- 2000/04/18 09:00
MHDA- 2000/06/17 09:00
CRDT- 2000/04/18 09:00
PHST- 2000/04/18 09:00 [pubmed]
PHST- 2000/06/17 09:00 [medline]
PHST- 2000/04/18 09:00 [entrez]
AID - 10.1099/0022-1317-81-5-1327 [doi]
PST - ppublish
SO  - J Gen Virol. 2000 May;81(Pt 5):1327-34. doi: 10.1099/0022-1317-81-5-1327.