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Anti-idiotypic antibodies reduce efficacy of the attenuated vaccine against highly pathogenic PRRSV challenge.

Yu Y, Cai X, Wang G, Kong N, Liu Y, Xiao Y, Zhang C, Mu Y, Xiao S, Zhao Q, Wang C, Zhang G, Hiscox JA, Zhou EM - BMC Vet. Res. (2014)

Bottom Line: The inability of current vaccines to provide effective protection against porcine reproductive and respiratory syndrome virus (PRRSV) infection is not fully understood.After PRRSV HuN4 challenge, the animals showed obvious clinical signs, including lung lesions, severe thymus atrophy and decreased production of IL-4 and higher level of viremia.It can result in poor health status with pneumonia and thymus atrophy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China. zhouem@nwsuaf.edu.cn.

ABSTRACT

Background: The inability of current vaccines to provide effective protection against porcine reproductive and respiratory syndrome virus (PRRSV) infection is not fully understood. One of the reasons might be the presence of anti-idiotypic antibodies (Ab2s) to the envelope glycoprotein GP5 induced by PRRSV infection since our previous studies demonstrated the presence of auto-Ab2s (aAb2s) in pigs infected with PRRSV. To test this hypothesis, PRRSV negative piglets were injected with a monoclonal Ab2 (Mab2-5G2) and aAb2s that are specific for anti-GP5 antibody, vaccinated with the attenuated PRRSV vaccine CH-1R and then challenged with the highly pathogenic PRRSV HuN4 strain. The animals were evaluated for clinical signs, pathological changes of the thymus and lungs, viremia, levels of serum antibodies and cytokines.

Results: The piglets injected with Mab2-5G2 or aAb2, and who received the attenuated PRRSV vaccine CH-1R before challenge, produced high levels of anti-N antibodies, IL-2 and IL-4, but low levels of neutralizing antibodies. After PRRSV HuN4 challenge, the animals showed obvious clinical signs, including lung lesions, severe thymus atrophy and decreased production of IL-4 and higher level of viremia.

Conclusion: When anti-GP5 Ab2s are present, the use of attenuated PRRSV vaccine CH-1R against HP-PRRSV infection is not recommended. It can result in poor health status with pneumonia and thymus atrophy.

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Related in: MedlinePlus

Pathological examinations of the thymus and lung on 28 DPC. Thymus of a piglet from Group 1 (A), Group 2 (B), and Group 5 (E) showed blurred boundaries between the thymus cortex and medulla. Thymus of a piglet from Group 3 (C), Group 4 (D) and Group 6 (F) showed no microscopic lesions (magnification × 50). Lungs of a piglet from Group 1 (G), Group 2 (H) and Group 5 (K) showed interstitial pneumonia lesions, lungs of a piglet from Group 3 (I) and Group 4 (J) showed mild interstitial pneumonia, and a Group 6 piglet (L) was normal (magnification × 200).
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Figure 3: Pathological examinations of the thymus and lung on 28 DPC. Thymus of a piglet from Group 1 (A), Group 2 (B), and Group 5 (E) showed blurred boundaries between the thymus cortex and medulla. Thymus of a piglet from Group 3 (C), Group 4 (D) and Group 6 (F) showed no microscopic lesions (magnification × 50). Lungs of a piglet from Group 1 (G), Group 2 (H) and Group 5 (K) showed interstitial pneumonia lesions, lungs of a piglet from Group 3 (I) and Group 4 (J) showed mild interstitial pneumonia, and a Group 6 piglet (L) was normal (magnification × 200).

Mentions: Thymuses collected on 28 DPC from Group 1 piglets showed typical depletion of cortical thymocytes accompanied by blurred boundaries between the thymus cortex and medulla as indicated by histology (Figure 3A). Similar microscopic lesions were seen in the thymuses of Group 2 and 5 piglets (Figure 3B, 3E). Group 3, 4 and 6 piglets showed no microscopic lesions of the thymus (Figure 3C, 3D, 3F). Interstitial pneumonia lesions were observed in Group 1, 2 and 5 piglets on 28 DPC (Figure 3G, 3H, 3K). The lung tissues from Group 3 and 4 piglets were widened slightly on 28 DPC (Figure 3I, 3J), and that from Group 6 piglets were normal (Figure 3L).


Anti-idiotypic antibodies reduce efficacy of the attenuated vaccine against highly pathogenic PRRSV challenge.

Yu Y, Cai X, Wang G, Kong N, Liu Y, Xiao Y, Zhang C, Mu Y, Xiao S, Zhao Q, Wang C, Zhang G, Hiscox JA, Zhou EM - BMC Vet. Res. (2014)

Pathological examinations of the thymus and lung on 28 DPC. Thymus of a piglet from Group 1 (A), Group 2 (B), and Group 5 (E) showed blurred boundaries between the thymus cortex and medulla. Thymus of a piglet from Group 3 (C), Group 4 (D) and Group 6 (F) showed no microscopic lesions (magnification × 50). Lungs of a piglet from Group 1 (G), Group 2 (H) and Group 5 (K) showed interstitial pneumonia lesions, lungs of a piglet from Group 3 (I) and Group 4 (J) showed mild interstitial pneumonia, and a Group 6 piglet (L) was normal (magnification × 200).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3921987&req=5

Figure 3: Pathological examinations of the thymus and lung on 28 DPC. Thymus of a piglet from Group 1 (A), Group 2 (B), and Group 5 (E) showed blurred boundaries between the thymus cortex and medulla. Thymus of a piglet from Group 3 (C), Group 4 (D) and Group 6 (F) showed no microscopic lesions (magnification × 50). Lungs of a piglet from Group 1 (G), Group 2 (H) and Group 5 (K) showed interstitial pneumonia lesions, lungs of a piglet from Group 3 (I) and Group 4 (J) showed mild interstitial pneumonia, and a Group 6 piglet (L) was normal (magnification × 200).
Mentions: Thymuses collected on 28 DPC from Group 1 piglets showed typical depletion of cortical thymocytes accompanied by blurred boundaries between the thymus cortex and medulla as indicated by histology (Figure 3A). Similar microscopic lesions were seen in the thymuses of Group 2 and 5 piglets (Figure 3B, 3E). Group 3, 4 and 6 piglets showed no microscopic lesions of the thymus (Figure 3C, 3D, 3F). Interstitial pneumonia lesions were observed in Group 1, 2 and 5 piglets on 28 DPC (Figure 3G, 3H, 3K). The lung tissues from Group 3 and 4 piglets were widened slightly on 28 DPC (Figure 3I, 3J), and that from Group 6 piglets were normal (Figure 3L).

Bottom Line: The inability of current vaccines to provide effective protection against porcine reproductive and respiratory syndrome virus (PRRSV) infection is not fully understood.After PRRSV HuN4 challenge, the animals showed obvious clinical signs, including lung lesions, severe thymus atrophy and decreased production of IL-4 and higher level of viremia.It can result in poor health status with pneumonia and thymus atrophy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China. zhouem@nwsuaf.edu.cn.

ABSTRACT

Background: The inability of current vaccines to provide effective protection against porcine reproductive and respiratory syndrome virus (PRRSV) infection is not fully understood. One of the reasons might be the presence of anti-idiotypic antibodies (Ab2s) to the envelope glycoprotein GP5 induced by PRRSV infection since our previous studies demonstrated the presence of auto-Ab2s (aAb2s) in pigs infected with PRRSV. To test this hypothesis, PRRSV negative piglets were injected with a monoclonal Ab2 (Mab2-5G2) and aAb2s that are specific for anti-GP5 antibody, vaccinated with the attenuated PRRSV vaccine CH-1R and then challenged with the highly pathogenic PRRSV HuN4 strain. The animals were evaluated for clinical signs, pathological changes of the thymus and lungs, viremia, levels of serum antibodies and cytokines.

Results: The piglets injected with Mab2-5G2 or aAb2, and who received the attenuated PRRSV vaccine CH-1R before challenge, produced high levels of anti-N antibodies, IL-2 and IL-4, but low levels of neutralizing antibodies. After PRRSV HuN4 challenge, the animals showed obvious clinical signs, including lung lesions, severe thymus atrophy and decreased production of IL-4 and higher level of viremia.

Conclusion: When anti-GP5 Ab2s are present, the use of attenuated PRRSV vaccine CH-1R against HP-PRRSV infection is not recommended. It can result in poor health status with pneumonia and thymus atrophy.

Show MeSH
Related in: MedlinePlus