Mycoplasma hyopneumoniae (MH) is the main causative agent of enzootic pneumonia of pigs. 49 pigs, presenting lung lesions, from 5 different herds were sampled at slaughterhouses. Lung lesions were individually scored according to Madec e Kobish (1982). MH was locally RT-PCR detected from each lung lesion according to Marois e coll. (2010) Lung samples were formalin-fixed. 5 μm paraffin sections were histologically evaluated with a score, ranging from 0 to 4, for BALT volume, severity of bronchi, bronchiolar disepithelization and subacute inflammation. Immunohistochemistry was carried out using commercial antibodies anti-MAC387 to detect macrophages, anti-CD3 for T-cells, anti CD79α for B-cells, Foxp3 for regulatory T-cells. The amount of antigen detected was scored from 0 to 4 based on the number of positive T and B cells foci per 4, 200 magnification fields. T-reg cells were individually counted in four BALT per pig. The average histological lung score ranged from 0.14 to 1.98. Results of RT-PCR were 32 positive and 17 negative samples. Lungs showed catarrhal bronco-interstitial pneumonia with increased volume of peribronchial, peribronchiolar and perivascular lymphoid tissue. 10 samples showed subacute inflammation and 22 showed lesions MH induced without secondary bacteria irruption. MAC387 positive cells were numerous in lung lesions (scored 4) affected by severe subacute inflammation while B, T and Treg cells were poorly represented. On the contrary, T cells were numerous in hyperplatic BALT MH induced (scored 3 to 4). B cells were scarcely represented in subacute inflammation; in MH induced BALT lesions were scored from 2 to 3. This study shows that Treg cells are very rare in hyperplastic BALT, suggesting a less active role of Treg cells in maintaining a low activation of immune system. Macrophages are numerous in subacute inflammation, while less in MH BALT, suggesting a low grade of apoptosis of cells of the follicle center.
EVALUATION OF INNATE AND ADAPTIVE IMMUNE RESPONSE IN PIGS NATURALLY INFECTED WITH MYCOPLASMA HYOPNEUMONIAE / Passeri, Benedetta; Corradi, Attilio; Catella, Alessia; Frascolla, Viviana; Montali, A; Alborali, Loris; Martinelli, Nicola. - 1:(2017), pp. 352-352. (Intervento presentato al convegno 9th European Symposium of Porcine Health Management (ESPHM) tenutosi a Praga nel 3 – 5 MAY 2017).
EVALUATION OF INNATE AND ADAPTIVE IMMUNE RESPONSE IN PIGS NATURALLY INFECTED WITH MYCOPLASMA HYOPNEUMONIAE
PASSERI, Benedetta;CORRADI, Attilio;CATELLA, ALESSIA;
2017-01-01
Abstract
Mycoplasma hyopneumoniae (MH) is the main causative agent of enzootic pneumonia of pigs. 49 pigs, presenting lung lesions, from 5 different herds were sampled at slaughterhouses. Lung lesions were individually scored according to Madec e Kobish (1982). MH was locally RT-PCR detected from each lung lesion according to Marois e coll. (2010) Lung samples were formalin-fixed. 5 μm paraffin sections were histologically evaluated with a score, ranging from 0 to 4, for BALT volume, severity of bronchi, bronchiolar disepithelization and subacute inflammation. Immunohistochemistry was carried out using commercial antibodies anti-MAC387 to detect macrophages, anti-CD3 for T-cells, anti CD79α for B-cells, Foxp3 for regulatory T-cells. The amount of antigen detected was scored from 0 to 4 based on the number of positive T and B cells foci per 4, 200 magnification fields. T-reg cells were individually counted in four BALT per pig. The average histological lung score ranged from 0.14 to 1.98. Results of RT-PCR were 32 positive and 17 negative samples. Lungs showed catarrhal bronco-interstitial pneumonia with increased volume of peribronchial, peribronchiolar and perivascular lymphoid tissue. 10 samples showed subacute inflammation and 22 showed lesions MH induced without secondary bacteria irruption. MAC387 positive cells were numerous in lung lesions (scored 4) affected by severe subacute inflammation while B, T and Treg cells were poorly represented. On the contrary, T cells were numerous in hyperplatic BALT MH induced (scored 3 to 4). B cells were scarcely represented in subacute inflammation; in MH induced BALT lesions were scored from 2 to 3. This study shows that Treg cells are very rare in hyperplastic BALT, suggesting a less active role of Treg cells in maintaining a low activation of immune system. Macrophages are numerous in subacute inflammation, while less in MH BALT, suggesting a low grade of apoptosis of cells of the follicle center.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
