Karl Haglund

Robust Recall and Long-Term Memory T-Cell Responses Induced by Prime-Boost Regimens with Heterologous Live Viral Vectors Expressing Human Immunodeficiency Virus Type 1 Gag and Env Proteins

ABSTRACT We investigated long-term memory and recall cellular immune responses to human immunodeficiency virus type 1 (HIV-1) Env and Gag proteins elicited by recombinant vesicular stomatitis viruses (VSVs) expressing Env and Gag. More than 7 months after a single vaccination with VSV-Env, ∼6% of CD8+ splenocytes stained with major histocompatibility complex class I tetramers containing the Env p18-I10 immunodominant peptide and showed a memory phenotype (CD44Hi). The level of tetramer-positive cells in memory was about 14% of the peak primary response. Recall responses elicited in these mice 5 days after boosting with a heterologous recombinant vaccinia virus expressing HIV-1 Env showed that 40 to 45% of CD8+ splenocytes were tetramer positive and activated (CD62LLo), and these cells produced gamma interferon after stimulation with Env peptide, indicating that they were functional. Five months after the boost, the long-term memory cell population (tetramer positive, CD44Hi) constituted 30% of the CD8+ splenocytes. Recall responses to HIV-1 Gag were examined in mice primed with VSV recombinants expressing HIV-1 Gag protein and boosted with a vaccinia virus recombinant expressing Gag. Using this protocol, we found that ∼40% of CD8+ splenocytes were activated (CD62LLo) and specific for a Gag immunodominant peptide (tetramer positive). The high-level Gag recall response elicited by the vaccinia virus-Gag was greater than that obtained by boosting with a VSV-Gag vector with a different VSV glycoprotein. The corresponding levels of CD44Hi memory cells were also higher long after boosting with vaccinia virus-Gag than after boosting with a glycoprotein exchange VSV-Gag. Our results show that VSV vectors elicit high-level memory CTL responses and that these can be amplified as much as six- to sevenfold using a heterologous boosting vector.

High-Level Primary CD8+ T-Cell Response to Human Immunodeficiency Virus Type 1 Gag and Env Generated by Vaccination with Recombinant Vesicular Stomatitis Viruses

ABSTRACT We investigated the primary cellular immune responses to human immunodeficiency virus type 1 (HIV-1) Env and Gag proteins elicited by recombinant vesicular stomatitis viruses (rVSVs). The primary response to Env peaked 5 to 7 days after intraperitoneal vaccination, at which time 40% of CD8+ cells were Env tetramer positive and activated (CD62LLo). These freshly isolated cells actively lysed target cells pulsed with the p18-I10 peptide and secreted gamma interferon and tumor necrosis factor alpha after stimulation with the Env p18-I10 peptide. The primary response to Env elicited by rVSVs was sixfold higher than that elicited by recombinant vaccinia viruses (rVVs) at 5 days postvaccination. An intranasal route of vaccination with VSV-Env also elicited a strong primary response to Env. The primary immune response to Gag elicited by rVSV peaked 7 days after vaccination, at which time 3% of CD8+ cells were Gag tetramer positive and CD62LLo and functional by intracellular cytokine staining. This response was eightfold higher than that elicited by rVV expressing Gag. VSV-GagEnv, which expresses both Gag and Env from a single recombinant, also induced strong cytotoxic T-lymphocyte (CTL) responses to both Env and Gag. Our quantitative analyses illustrate the potency of the VSV vector system in CTL induction.

Characterization and Management of Cardiac Involvement of Thymic Epithelial Tumors

Introduction: Although thymic epithelial tumors (TETs) commonly infiltrate mediastinal structures, cardiac involvement is uncommon and has not been systematically studied. The purpose of this study was to describe our single-institution experience of the clinical presentation, treatment, and follow-up of cardiac involvement in patients with TETs. Methods: A single-institution retrospective review of cardiac involvement among patients with TETs from 2008 to 2012. Results: The frequency of cardiac involvement was 4%. All five patients with confirmed cardiac disease had left heart involvement. Only one patient was symptomatic. Myocardial invasion was the most common mode of involvement followed by transvenous spread. Surgical resection of the involved area was attempted in three patients: in one, surgery was aborted because of extensive myocardial involvement; in the other two patients, resection was incomplete. Surgery averted a potentially catastrophic hemodynamic complication in one patient. However, cardiac tumor recurred in both patients who underwent incomplete resection. One patient underwent radiation therapy resulting in complete regression of an aortic root mass. Conclusions: This study represents the most comprehensive review of cardiac involvement in patients with TETs. In contrast to previous single-case reports, we found a preponderance of asymptomatic presentation, left heart involvement, and myocardial invasion. Dynamic cardiovascular magnetic resonance imaging should be considered in cases when cardiac involvement is suspected. Although immediate surgical resection is indicated for impending hemodynamic compromise, long-term palliation with surgery for myocardial involvement seems poor, especially when complete resection cannot be performed. Radiation therapy should be considered in selected patients.

Computed tomography-based radiation therapy of ovarian remnants for symptomatic persistent endometriosis.

BACKGROUND: Endometriosis, a major cause of pelvic pain in women, is driven by estrogen. Ovarian remnant irradiation may alleviate pelvic pain by eliminating estrogen production in appropriately selected women with endometriosis. CASE: Three patients with endometriosis causing incapacitating pelvic pain received 3D-imaging–based external beam radiation to doses of 1,500 to 2,100 cGy. All had pre-irradiation premenopausal follicle stimulating hormone levels and imaging evidence of ovarian remnants. None were candidates for further medical or surgical interventions. By 3 months after radiation, follicle stimulating hormone levels reached postmenopausal levels in all three patients, with complete resolution of the severe pelvic pain. CONCLUSION: Radiation therapy effectively induced menopause and relieved refractory pain from endometriosis. Careful selection of patients is necessary, given the potential for an increased long-term risk of radiation-related complications.