Cellular Innate Immunity against PRRSV (and IAV)

Vet Sci. 2019 Mar 11;6(1). pii: E26. doi: 10.3390/vetsci6010026.

Cellular Innate Immunity against PRRSV and Swine Influenza Viruses.

Crisci E1,2, Fraile L3, Montoya M4.

Author information

1

Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA. ecrisci@ncsu.edu.

2

Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27607, USA. ecrisci@ncsu.edu.

3

Universitat de Lleida, 25198 Lleida, Spain. lorenzo.fraile@ca.udl.cat.

4

Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CIB-CSIC), 28040 Madrid, Spain. maria.montoya@cib.csic.es.

Abstract

Porcine respiratory disease complex (PRDC) is a polymicrobial syndrome that results from a combination of infectious agents, such as environmental stressors, population size, management strategies, age, and genetics. PRDC results in reduced performance as well as increased mortality rates and production costs in the pig industry worldwide. This review focuses on the interactions of two enveloped RNA viruses-porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza virus (SwIV)-as major etiological agents that contribute to PRDC within the porcine cellular innate immunity during infection. The innate immune system of the porcine lung includes alveolar and parenchymal/interstitial macrophages, neutrophils (PMN), conventional dendritic cells (DC) and plasmacytoid DC, natural killer cells, and γδ T cells, thus the in vitro and in vivo interactions between those cells and PRRSV and SwIV are reviewed. Likewise, the few studies regarding PRRSV-SwIV co-infection are illustrated together with the different modulation mechanisms that are induced by the two viruses. Alterations in responses by natural killer (NK), PMN, or γδ T cells have not received much attention within the scientific community as their counterpart antigen-presenting cells and there are numerous gaps in the knowledge regarding the role of those cells in both infections. This review will help in paving the way for future directions in PRRSV and SwIV research and enhancing the understanding of the innate mechanisms that are involved during infection with these viruses.

KEYWORDS: 

PRRSV; innate immunity; pig; swine influenza virus

PMID:

 

30862035

 

DOI:

 

10.3390/vetsci6010026

Influence of age, group size, and presence of PRRSv on oral fluids collection

Vet J. 2019 Feb;244:13-15. doi: 10.1016/j.tvjl.2018.12.005. Epub 2018 Dec 7.

Influence of age, group size and the presence of porcine reproductive and respiratory syndrome virus on the collection of oral fluids.

Graage R1, Hennig-Pauka I2, Arbinger H2, Ritzmann M3, Ladinig A2.

Author information

1

Department for Farm Animals and Veterinary Public Health, University Clinic for Swine, University of Veterinary Medicine Vienna, Vienna Vetertinaerplatz 1, A-1220 Vienna, Austria. Electronic address: rgraage@vetclinics.uzh.ch.

2

Department for Farm Animals and Veterinary Public Health, University Clinic for Swine, University of Veterinary Medicine Vienna, Vienna Vetertinaerplatz 1, A-1220 Vienna, Austria.

3

Clinic for Swine at the Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich, Sonnenstrasse 16, D-85764 Oberschleißheim, Germany.

Abstract

Pen-based oral fluid (OF) samples have been approved for detecting porcine reproductive and respiratory syndrome virus (PRRSV) RNA and antibodies. The aim of the study was to investigate the influence of age, group size and the presence of PRRSV infection on sampling using pen-based OF collected by presenting pigs with a rope to chew. Samples were collected from pigs of 4/5 weeks of age, 7/8 weeks of age and 12/14 weeks of age. Subsequent PRRSV-PCR and ELISA analyses of OF and serum samples were performed. In this study, 76.5-81.9% of pigs chewed the rope. The group size had significant impact on the pig-rope-interaction (P=0.047). OF and serum had an almost perfect and significant agreement for the detection of antibodies (κ=0.829, P<0.001) and a fair and not significant agreement (κ=0.347, P=0.75) for the detection PRRSV-genome.

Copyright © 2018 Elsevier Ltd. All rights reserved.

KEYWORDS: 

ELISA; Oral fluid; PCR; PRRSV; Rope; Surveillance

PMID:

 

30825888

 

DOI:

 

10.1016/j.tvjl.2018.12.005

Litter oral fluid testing was more sensitive than bleeding the weakest pig in the litter (for PRRSV detection in suckling pigs)

Porcine Health Manag. 2019 Feb 19;5:8. doi: 10.1186/s40813-019-0115-z. eCollection 2019.

Monitoring PRRSV-1 in suckling piglets in an endemic herd using reverse transcriptase quantitative real time polymerase chain reaction: comparison of the rate of detection in serum and oral fluid samples and evaluation of pooling.

Lebret A1, Boulbria G1, Berton P1, Moalic PY2, Le Guennec J1, Bouchet F1, Auvigne V3, Normand V1.

Author information

1

Porc. Spective Swine Vet Pratice, Chene Vert Conseil veterinary group, ZA du Gohélève, 56920 Noyal-Pontivy, France.

2

Labofarm Finalab Veterinary Laboratory Group, 4 rue Théodore Botrel, 22600 Loudéac, France.

3

Ekipaj, 22 rue d'Assas, 49000 Angers, France.

Abstract

BACKGROUND: 

Defining shedding and exposure status for PRRSV is essential in herd stabilisation protocols and weaning-age pigs is a key subpopulation. Oral fluid (OF) sampling is a welfare-friendly and cost saving promising alternative to blood sampling. The first objective of our study was to compare the rate of detection of PRRSV-1 in individual serum sample, individual OF sample, litter-based OF sample, collected the day before weaning. The second objective was to evaluate the interest of pooling samples.

RESULTS: 

The study was performed on a 210-sows, PRRSV-1 exposed, with confirmed shedding, non-vaccinated against PRRSV, herd. 80 litters were sampled and 26 were viropositive and therefore included. The rate of detection of PRRSV-1 with RT-qrtPCR in blood samples, iOF and cOF was 67, 23 and 77%, respectively. The Ct values from RT-qrtPCR on collective OF were statistically lower if the serum of the piglet of the litter was positive. The lower the Cycle threshold (Ct) value of RT-qrtPCR on collective OF, the higher the probability that the serum sampled in the same litter was positive. Ability to detect PRRSV RNA after pooling was 67% for sera and 58% for cOF.

CONCLUSIONS: 

The rate of detection of PRRSV-1 was about the same in cOF and blood samples. Virus sequencing, if required, should be performed on individual serum samples. The smaller the Ct of a cOF sample from a litter, the greater the likelihood that the serum sample from a piglet of that litter is positive.A cost-effective and representative sampling protocol to monitor sow herds stabilisation of a sow batch could be: to collect both cOF and one serum sample per litter; to perform firstly RT-qrtPCR on pooled cOF; in case of negative results to consider the batch negative; in case of positive results in a unvaccinated herd or a killed vaccine vaccinated one to consider the batch positive; in case of positive result in a herd vaccinated with a modified live vaccine serum samples of litters with positive cOF should be tested for sequencing (selecting the litters with the lowest Ct for cOF).

KEYWORDS: 

Diagnostic; Oral fluid; PCR; PRRS; Pig; Pooling; Serum; Suckling piglets

PMID:

 

30820335

 

PMCID:

 

PMC6381726

 

DOI:

 

10.1186/s40813-019-0115-z