Rønneseth Anita, Pettersen Eirin Fausa, Wergeland Heidrun I
Department of Biology, University of Bergen, Bergen High-Technology Center, PO Box 7800, N-5020 Bergen, Norway.
Fish Shellfish Immunol. 2006 Apr;20(4):610-20. doi: 10.1016/j.fsi.2005.08.004. Epub 2005 Oct 20.
Salmon B-cells and neutrophils were studied by flow cytometry in IPNV infected salmon. A highly virulent strain of IPNV was used for challenge of parr and post-smolts. The parr were challenged by intraperitoneal (ip) injection while salmon post-smolts were challenged by ip injection or cohabitation. No mortality occurred in the parr groups, but a cumulative mortality of about 50% was obtained in cohabitant infected post-smolt groups and less than 10% in ip challenged post-smolts. The virus levels were low in head kidney (HK) samples from survivors compared to dead fish. The percentages of neutrophilic granulocytes and Ig+ cells (B-cells) were analysed using HK and blood samples from survivors. The cell populations were identified by monoclonal antibodies (MAb) E3D9, recognising neutrophils, and G2H3 recognising Ig+ cells (B-cells). Parr sampling for leucocyte analyses took place about 1.5 weeks prior to and about 4 weeks post challenge. This corresponded to about 8 and 2.5 weeks before the fish were adapted to seawater transfer. In parr head kidney leucocytes (HKL) we observed significantly lower (p < 0.05) levels of neutrophils in ip infected fish compared to non-infected control fish. The post-smolt sampling from infected fish took place 2 weeks prior to and in the fifth and sixth week post challenge. HKL samples from both surviving cohabitants and ip injected fish had significantly (p < 0.05) lower levels of neutrophils than non-infected control fish. The cohabitant fish also had significantly (p < 0.05) higher levels of B-cells in HKL compared to ip injected fish. No significant changes in B-cells in HKL or peripheral blood leucocytes (PBL) was observed in infected parr or ip infected post-smolts compared to control fish. The relative leucocyte levels of the fish prior to challenge and in non-infected control fish are in accordance with earlier findings. The results indicate that non-specific immune cells like neutrophils are highly influenced by IPNV infection of parr and post-smolts several weeks post challenge.
通过流式细胞术对感染传染性胰腺坏死病毒（IPNV）的鲑鱼的B细胞和中性粒细胞进行了研究。使用高毒力的IPNV毒株对幼鲑和成鱼进行攻毒。幼鲑通过腹腔注射进行攻毒，而成鱼则通过腹腔注射或同居感染的方式进行攻毒。幼鲑组未出现死亡，但同居感染的成鱼组累积死亡率约为50%，腹腔注射攻毒的成鱼死亡率低于10%。与死亡鱼相比，存活鱼的头肾（HK）样本中的病毒水平较低。使用存活鱼的头肾和血液样本分析中性粒细胞和Ig+细胞（B细胞）的百分比。通过单克隆抗体（MAb）E3D9识别中性粒细胞，G2H3识别Ig+细胞（B细胞）来鉴定细胞群体。在攻毒前约1.5周和攻毒后约4周采集幼鲑样本进行白细胞分析。这分别对应于鱼适应海水转移前约8周和2.5周。在幼鲑的头肾白细胞（HKL）中，我们观察到腹腔感染的鱼与未感染的对照鱼相比，中性粒细胞水平显著降低（p < 0.05）。对感染鱼的成鱼样本采集在攻毒前2周以及攻毒后第5周和第6周进行。同居存活鱼和腹腔注射鱼的HKL样本中的中性粒细胞水平均显著低于未感染的对照鱼（p < 0.05）。与腹腔注射鱼相比，同居鱼的HKL中B细胞水平也显著更高（p < 0.05）。与对照鱼相比，在感染的幼鲑或腹腔感染的成鱼中，HKL或外周血白细胞（PBL）中的B细胞未观察到显著变化。攻毒前鱼的相对白细胞水平以及未感染对照鱼的水平与早期研究结果一致。结果表明，在攻毒后数周，像中性粒细胞这样的非特异性免疫细胞受到IPNV对幼鲑和成鱼感染的高度影响。
