Localization of Swine Influenza Virus in Naturally Infected Pigs

Abstract

Abstract. Swine influenza virus (SIV) RNA and antigen were detected in 15 naturally infected pigs by in situ hybridization using a nonradioactive digoxigenin-labeled cDNA probe and by immunohistochemistry using an influenza virus H1N1-specific monoclonal antibody. A 582-base pair cDNA probe for viral RNA encoding the nucleocapsid protein of SIV type A H1N1 strain was generated by the reverse transcription polymerase chain reaction. In situ hybridization and immunohistochemistry gave similar results for serial sections from each of 15 lung samples. Positive cells typically exhibited a dark brown (in situ hybridization) or red (immunohistochemistry) reaction product in the nucleus and cytoplasm without background staining. A strong positive signal for both in situ hybridization and immunohistochemistry was detected mainly in the bronchial and bronchiolar epithelial cells. A less intense signal was detected in the interstitial and alveolar macrophages. Simultaneous detection of hybridization and immunohistochemical signals on serial sections provided evidence that SIV had replicated in positive cells. The in situ hybridization technique developed in this study was useful for the detection of SIV RNA in tissues taken from naturally infected pigs and may be a valuable technique for studying the pathogenesis of SIV infection.

Infection of porcine bone marrow-derived macrophages by porcine respiratory and reproductive syndrome virus impairs phagosomal maturation

“…Each of these functions is critical to the various roles played by phagocytes in the innate and adaptive immune systems, including the clearing of microbes and antigen presentation to T-cells (two steps involved in the significant morbidity and mortality observed in swine herds infected with PRRSV). Our model may also prove useful for the study other important viruses such as porcine circovirus and influenza A, both of which target the alveolar macrophages of swine (Jung et al, 2002;McNeilly et al, 1996). Because little is known about the effects of viral infections in general on phagosomal maturation, the use of bone marrow-derived macrophage models may lead to important discoveries in the pathogenic mechanisms of phagocytic infection.…”

Alteraciones morfológicas en pulmón por la influenza A H1N1/v09 en autopsias, Colombia, 2009

“…Taubenberger, et al (2010), reportaron marcaciones para el antígeno en el epitelio pseudoestratificado del árbol traquebronquial y en el epitelio bronquiolar, en casos de autopsia (12). De forma similar, en los estudios con cerdos infectados naturalmente, se ha observado una fuerte inmunorreacción de antígenos virales en células del epitelio bronquiolar y bronquial, con menor marcación en el epitelio alveolar (31).…”

Orientações para o diagnóstico de influenza em suínos

“…Como o vírus replica no epitélio respiratório, usando anticorpos específicos (por exemplo, contra a nucleoproteína viral -NP), detecta-se o antígeno viral nas células epiteliais dos bronquíolos e brôn-quios (Fig.6C), e em menor escala, nos pneumócitos tipo II dos septos alveolares ou células dentro do lúmen alveolar (pneumócitos descamados ou macrófagos alveolares) (Gauger et al 2012a). O antígeno NP é detectado principalmente no núcleo, e em menor expressão no citoplasma (Vincent et al 1997, Jung et al 2002, Gauger et al 2012a. O resultado positivo geralmente está associado à fase aguda da doença, ou seja, até 5-7 dias pós-infecção (Weingartl et al 2010, Gauger et al 2012a), embora marcação de poucas células infectadas é observada até 13 dias pós-infecção (Weingartl et al 2010).…”