Horohov D W, Dunham J, Liu C, Betancourt A, Stewart J C, Page A E, Chambers T M
Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, United States.
Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, United States.
Vet Immunol Immunopathol. 2015 Mar 15;164(1-2):24-9. doi: 10.1016/j.vetimm.2014.12.015. Epub 2015 Jan 8.
Adjuvants are included with many inactivated and some modified live vaccines to enhance immune responses to specific antigens. While early vaccines relied exclusively upon aluminum salts, still the major adjuvant used in human vaccines, other adjuvant products are used in veterinary medicine. In addition to enhancing antigen presentation, adjuvants can also enhance the development of specific immune responses. Thus, alum adjuvants often preferentially stimulate humoral immune responses. By contrast, lipid-based adjuvants are often more effective at stimulating cell-mediated immune responses. Metastim(®) is a lipid-based adjuvant reported to elicit both humoral and cellular immune responses, though the mechanism responsible for this activity remains unclear. In this study, we compared the ability of equine influenza virus vaccines containing either saline or Metastim(®) or an aluminum phosphate adjuvant to stimulate antigen presenting cell function in vivo. Six ponies were intradermally inoculated with inactivated equine influenza (KY97) mixed with either adjuvant or saline. Multiple sites were injected so that biopsies could be collected at different times post injection. The 4mm punch biopsies were formalin-fixed, paraffin-embedded, and stained with hematoxylin and eosin (H&E). Total RNA was isolated from 2mm punch biopsies for the determination of gene expression by real-time PCR. H&E staining revealed a variety of cells recruited to the injection sites, including lymphocytes, neutrophils, eosinophils and macrophages. Real-time PCR analysis of the injection site confirmed this cellular infiltration and identified increased expression of activation markers. Both vaccines also stimulated gene expressions of pro-inflammatory cytokines. The vaccine containing Metastim(®) elicited significantly higher gene expression of interferon-γ, IL-12, CD4 and CD83 compared to alum (p<0.05). While the greater induction of IFNγ-related gene expression indicates that Metastim(®) can elicit Th-1 immune responses more effectively than the aluminum salt, there was also evidence of Th2 cytokine induction.
许多灭活疫苗和一些改良活疫苗中都添加了佐剂，以增强对特定抗原的免疫反应。早期疫苗仅依赖铝盐，铝盐仍是人类疫苗中使用的主要佐剂，而其他佐剂产品则用于兽医学。除了增强抗原呈递外，佐剂还可以促进特异性免疫反应的发展。因此，铝盐佐剂通常优先刺激体液免疫反应。相比之下，基于脂质的佐剂在刺激细胞介导的免疫反应方面通常更有效。Metastim(®)是一种基于脂质的佐剂，据报道它能引发体液免疫和细胞免疫反应，但其产生这种活性的机制尚不清楚。在本研究中，我们比较了含有生理盐水、Metastim(®)或磷酸铝佐剂的马流感病毒疫苗在体内刺激抗原呈递细胞功能的能力。六匹小马皮内接种灭活马流感病毒（KY97），该病毒与佐剂或生理盐水混合。注射多个部位，以便在注射后不同时间采集活检样本。4毫米打孔活检样本用福尔马林固定、石蜡包埋，并用苏木精和伊红（H&E）染色。从2毫米打孔活检样本中分离总RNA，通过实时PCR测定基因表达。H&E染色显示多种细胞被募集到注射部位，包括淋巴细胞、中性粒细胞、嗜酸性粒细胞和巨噬细胞。对注射部位的实时PCR分析证实了这种细胞浸润，并确定了激活标志物的表达增加。两种疫苗还刺激了促炎细胞因子的基因表达。与铝盐相比，含有Metastim(®)的疫苗诱导的干扰素-γ、IL-12、CD4和CD83基因表达显著更高（p<0.05）。虽然IFNγ相关基因表达的更大诱导表明Metastim(®)比铝盐能更有效地引发Th-1免疫反应，但也有Th2细胞因子诱导的证据。
