Lau Quintin, Canfield Paul J, Higgins Damien P
Faculty of Veterinary Science, The University of Sydney, B14 McMaster Building, Camperdown, NSW 2006, Australia.
Vet Immunol Immunopathol. 2012 Jun 15;147(1-2):35-43. doi: 10.1016/j.vetimm.2012.04.010. Epub 2012 Apr 19.
Understanding and measuring immune activity of the koala (Phascolarctos cinereus), is important to studies of the epidemiology and impact of the widespread chlamydial and koala retroviral (KoRV) infections that occur in this iconic but increasingly threatened species. To explore the interaction of disease and immunity, and to assess the potential for use of class II major histocompatibility complex (MHCII) upregulation as an indicator of lymphocyte activation in in vitro immune assays, we have investigated the expression of MHCII in koala lymphocytes by flow cytometry. MHCII expression was upregulated in mitogen stimulated B lymphocytes in vitro but no such increase was detected in vivo in free-living koalas with active inflammation. In assessing phenotypic baseline data of captive koalas, we have identified that MHCII is expressed predominantly on circulating B lymphocytes (85.7 ± 2.4%) but on very few T lymphocytes (3.4 ± 1.9%), even following activation, and suggest that the latter finding might be compensated by the greater absolute numbers of peripheral blood B lymphocytes in this species relative to many eutherian species.
了解和测量考拉（Phascolarctos cinereus）的免疫活性，对于研究这种标志性但日益受到威胁的物种中广泛存在的衣原体和考拉逆转录病毒（KoRV）感染的流行病学及影响至关重要。为了探究疾病与免疫的相互作用，并评估在体外免疫测定中使用II类主要组织相容性复合体（MHCII）上调作为淋巴细胞活化指标的潜力，我们通过流式细胞术研究了考拉淋巴细胞中MHCII的表达。体外有丝分裂原刺激的B淋巴细胞中MHCII表达上调，但在患有活动性炎症的自由生活考拉体内未检测到这种增加。在评估圈养考拉的表型基线数据时，我们发现MHCII主要在循环B淋巴细胞（85.7±2.4%）上表达，而在T淋巴细胞上表达极少（3.4±1.9%），即使在活化后也是如此，并表明相对于许多真兽类物种，该物种外周血B淋巴细胞的绝对数量更多，这可能弥补了后一发现。
