Respiratory Syncytial Virus Infection Induces Expression of Inducible Nitric Oxide Synthase, CD3, and CD8 in Naturally Occurring Pneumonia in Lambs

Abstract

Respiratory syncytial virus (RSV) is an RNA virus that belongs to the Pneumovirus genus of the Paramyxoviridae family. The aim of this study was to evaluate the expressions of inducible nitric oxide synthetase (iNOS), CD3 (pan T cells), and CD8 (cytotoxic T cells) in lamb lungs naturally infected with RSV using immunohistochemistry (IHC). For this purpose, 100 pneumonic and 10 control lung tissue samples were taken from lambs slaughtered in the slaughterhouse after macroscopic examination. The streptavidin– peroxidase method (ABC) was used for IHC staining, and it revealed RSV positivity in 18 of 100 examined lungs with pneumonia (18%). These positive cases were then immunostained for iNOS, CD3, and CD8, and compared to controls. In all these cases, an increase in iNOS expression (100%) was detected, the higher number of CD3+ T lymphocytes was detected in 14 (78%) cases while CD8+ T lymphocytes were detected in five (28%) cases, only. Given the increase of iNOS immunoexpression in all RSV-positive cases and increase in the number of CD3+ T lymphocytes in most cases, it was concluded that iNOS and CD3+ T lymphocytes play an important role in the immune response in lamb pneumonia with naturally occurring RSV infection. With this study,

Respiratorni sincicijalni virus (RSV) je RNK virus koji pripada rodu Pneumovirus iz porodice Paramyxoviridae. Cilj ove studije bio je da se proceni ekspresija inducibilne sintetaze azotnog oksida (iNOS), CD3 (pan T ć elija) i CD8 (citotoksičnih T ć elija) u pluć ima jagnjadi prirodno infi cirane RSV-om primenom imunohistohemije (IHC). U tu svrhu uzeto je 100 uzoraka pluć a i 10 kontrolnih uzoraka pluć nog tkiva jagnjadi zaklanih u klanici, nakon makroskopskog pregleda. Za IHC bojenje korišć ena je metoda streptavidin-peroksidaze (ABC) koja je otkrila pozitivnost RSV u 18 od 100 pregledanih pneumoničnih pluć a (18%). Ovi pozitivni slučajevi su zatim imunohistohemijski obrađeni za iNOS, CD3 i CD8 i upoređeni sa kontrolama. U svim ovim slučajevima otkriven je porast ekspresije iNOS (100%), već i broj CD3 + T limfocita otkriven je u 14 (78%) slučajeva, dok su CD8 + T limfociti dokayani samo u pet (28%) slučajeva. S obzirom na poveć anje iNOS imunoekspresije u svim RSV-pozitivnim slučajevima i poveć anje broja CD3 + T limfocita u već ini slučajeva, zaključeno je da iNOS i CD3 + T limfociti igraju važnu ulogu u imunskom odgovoru kod RSV pneumonije jagnjadi koja se prirodno javlja. Ovom studijom je prvi put procenjena uloga pomenutih markera kod jagnjadi prirodno zaraženih RSV-om.