Ruiz-López María José, Monello Ryan J, Schuttler Stephanie G, Lance Stacey L, Gompper Matthew E, Eggert Lori S
Department of Fisheries and Wildlife Sciences, University of Missouri, Columbia, MO 65211, USA.
Department of Fisheries and Wildlife Sciences, University of Missouri, Columbia, MO 65211, USA.
Infect Genet Evol. 2014 Dec;28:317-27. doi: 10.1016/j.meegid.2014.10.015. Epub 2014 Oct 24.
Major Histocompatibility Complex (MHC) variability plays a key role in pathogen resistance, but its relative importance compared to environmental and demographic factors that also influence resistance is unknown. We analyzed the MHC II DRB exon 2 for 165 raccoons (Procyon lotor) in Missouri (USA). For each animal we also determined the presence of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to two highly virulent pathogens, canine distemper virus (CDV) and parvovirus. We investigated the role of MHC polymorphism and other demographic and environmental factors previously associated with predicting seroconversion. In addition, using an experimental approach, we studied the relative importance of resource availability and contact rates. We found important associations between IgG antibody presence and several MHC alleles and supertypes but not between IgM antibody presence and MHC. No effect of individual MHC diversity was found. For CDV, supertype S8, one allele within S8 (Prlo-DRB(∗)222), and a second allele (Prlo-DRB(∗)204) were positively associated with being IgG+, while supertype S4 and one allele within the supertype (Prlo-DRB(∗)210) were negatively associated with being IgG+. Age, year, and increased food availability were also positively associated with being IgG+, but allele Prlo-DRB(∗)222 was a stronger predictor. For parvovirus, only one MHC allele was negatively associated with being IgG+ and age and site were stronger predictors of seroconversion. Our results show that negative-frequency dependent selection is likely acting on the raccoon MHC and that while the role of MHC in relation to other factors depends on the pathogen of interest, it may be one of the most important factors predicting successful immune response.
主要组织相容性复合体（MHC）的变异性在病原体抗性中起着关键作用，但其与同样影响抗性的环境和人口统计学因素相比的相对重要性尚不清楚。我们分析了美国密苏里州165只浣熊（Procyon lotor）的MHC II DRB外显子2。对于每只动物，我们还测定了针对两种高致病性病原体犬瘟热病毒（CDV）和细小病毒的免疫球蛋白G（IgG）和免疫球蛋白M（IgM）抗体的存在情况。我们研究了MHC多态性以及先前与预测血清转化相关的其他人口统计学和环境因素的作用。此外，我们采用实验方法研究了资源可用性和接触率的相对重要性。我们发现IgG抗体的存在与几个MHC等位基因和超型之间存在重要关联，但IgM抗体的存在与MHC之间没有关联。未发现个体MHC多样性有影响。对于CDV，超型S8、S8内的一个等位基因（Prlo-DRB(∗)222）和第二个等位基因（Prlo-DRB(∗)204）与IgG阳性呈正相关，而超型S4和该超型内的一个等位基因（Prlo-DRB(∗)210）与IgG阳性呈负相关。年龄、年份和食物可利用性增加也与IgG阳性呈正相关，但等位基因Prlo-DRB(∗)222是更强的预测因子。对于细小病毒，只有一个MHC等位基因与IgG阳性呈负相关，年龄和地点是血清转化更强的预测因子。我们的结果表明，负频率依赖性选择可能作用于浣熊的MHC，并且虽然MHC相对于其他因素的作用取决于所关注的病原体，但它可能是预测成功免疫反应的最重要因素之一。
