Blocking immune evasion as a novel immunotherapy for recurrent HSV-2 infection

描述（由申请人提供）：单纯疱疹病毒2型（HSV-2）是生殖器溃疡的主要原因，在全世界感染了5亿人。生殖器疱疹是情感上的痛苦，是威胁生命的新生儿感染在分娩过程中，是一个主要的风险因素获得和传播艾滋病毒感染。每日抑制性抗病毒治疗是目前唯一 目前，生殖器疱疹的复发性感染可获得有效的治疗;然而，这种方法在预防疾病爆发方面仅取得部分成功，在减少艾滋病毒感染方面无效。 我们将评估两种免疫疫苗在控制HSV-2复发感染方面的效果。这些疫苗是我们实验室首创的;一种涉及HSV-2复制能力减毒活病毒（gE 2-del），另一种涉及三价亚单位抗原疫苗（gC 2/gD 2/gE 2）。一种可复制的水痘带状疱疹活病毒疫苗目前用于预防带状疱疹，带状疱疹是一种由密切相关的疱疹病毒引起的复发性感染。我们将单独评价活病毒和亚单位抗原疫苗，并结合预期活病毒疫苗将刺激CD 4+和CD 8 + T细胞应答，而gC 2/gD 2/gE 2亚单位抗原疫苗将改善体液免疫。包括HSV-2 gD以增强中和抗体，包括gD 2和gE 2以刺激阻断细胞间扩散的抗体，包括gC 2和gE 2以产生防止抗体和补体的免疫逃避的抗体。三价亚单位抗原作为小鼠中原发性生殖器疱疹的预防性疫苗的令人印象深刻的功效支持阻断免疫逃避作为复发性感染的免疫疗法的概念。 在R21阶段，我们将评估活病毒和三价亚单位抗原疫苗降低豚鼠生殖器复发感染频率和严重程度的能力。我们将 确定免疫疗法是否减少允许HIV复制的CD 4 + T细胞向生殖器组织的浸润（R33期）。我们将通过测量HSV-2感染豚鼠的先天性、抗体和T细胞免疫应答来评估对复发性生殖器感染的保护的免疫相关性，所述HSV-2感染豚鼠是模拟疫苗接种的或用最佳表现的治疗性疫苗免疫的（R33期）。定义保护的免疫相关性将有助于未来的研究，以解决是否可以在HSV-2感染的人中产生可比的免疫应答。我们将通过使用单基因组扩增（SGA）技术比较在病毒接种物、急性感染期间分离的病毒和治疗性免疫后分离的病毒（R21和R33阶段）中检测到的突变变体，来确定用gC 2/gD 2/gE 2亚单位抗原进行的治疗性免疫是否选择在体内免疫压力下出现的突变体。SGA为病毒库内的微小突变变体提供了一种准确的检测方法，与其他测序方法相比，该方法对检测构象表位中的突变更敏感，并且是一种识别其他成功的免疫缺陷疫苗的潜在不良后果的创新方法。

DESCRIPTION (provided by applicant): Herpes simplex virus type 2 (HSV-2) is the leading cause of genital ulcers and infects a half-billion people worldwide. Genital herpes is emotionally distressing, is life threatening to newborns infected during delivery, and is a major risk factor fr acquiring and transmitting HIV infection. Daily suppressive antiviral therapy is currently the only treatment available for recurrent genital herpes infections; however, this approach is only partially successful in preventing outbreaks and is ineffective in reducing HIV acquisition. We will evaluate the efficacy of two immunotherapeutic vaccines at controlling HSV-2 recurrent infection. The vaccines were pioneered in our lab; one involves a HSV-2 replication competent, attenuated live virus (gE2-del) and the other a trivalent subunit antigen vaccine (gC2/gD2/gE2). A replication competent varicella zoster live virus vaccine is currently used to prevent shingles, which is a recurrent infection caused by a closely related herpes virus. We will evaluate the live virus and subunit antigen vaccines individually and in combination with the expectation that the live virus vaccine will stimulate CD4+ and CD8+ T-cell responses, while the gC2/gD2/gE2 subunit antigen vaccine will improve humoral immunity. HSV-2 gD is included to enhance neutralizing antibodies, gD2 and gE2 to stimulate antibodies that block cell-to-cell spread, and gC2 and gE2 to produce antibodies that prevent immune evasion from antibody and complement. The impressive efficacy of the trivalent subunit antigens as a prophylactic vaccine for primary genital herpes in mice supports the concept of blocking immune evasion as immunotherapy for recurrent infections. In the R21 phase, we will evaluate the live virus and trivalent subunit antigen vaccines for their ability to reduce the frequency and severity of recurrent genital infection in guinea pigs. We will determine whether immunotherapy reduces the infiltration into genital tissues of CD4+ T-cells that are permissive for HIV replication (R33 phase). We will evaluate the immune correlates of protection against recurrent genital infection by measuring innate, antibody and T cell immune responses in HSV-2 infected guinea pigs that are either mock-vaccinated or immunized with the best-performing therapeutic vaccine (R33 phase). Defining the immune correlates of protection will facilitate future studies that address whether comparable immune responses can be generated in HSV-2 infected humans. We will determine whether therapeutic immunization with gC2/gD2/gE2 subunit antigens selects for mutants that emerge under immune pressure in vivo by using single genome amplification (SGA) technology to compare mutant variants detected in the virus inoculum, virus isolated during acute infection and virus isolated after therapeutic immunization (R21 and R33 phases). SGA provides an accurate detection assay for minor mutant variants within a virus pool that is more sensitive for detecting mutations in conformational epitopes that other sequencing methods and is an innovative approach to identify potentially unwanted consequences of an otherwise successful immunotherapeutic vaccine.