An elevated number of Gr-1 + CD11b + myeloid cells has been described in mice bearing transplantable tumors, and has been associated with immune suppression. We examined the role of such myeloid suppressor cells in mice bearing the spontaneously transformed syngeneic mouse ovarian surface epithelial cell line, 1D8. We observed high levels of CD80 expression by Gr-1 + CD11b + cells from spleen, ascites, and tumor tissue of mice bearing 1D8 ovarian carcinoma, whereas CD40 and CD86 were absent. CD80 expression was not detected on Gr-

Vaccination with virus-like particles (VLP), comprising both L1 and L2 of human papillomavirus (HPV) genital types 6, 16, and 18, induces predominantly type-specific neutralizing antibodies. L2 polypeptide vaccines protect animals against experimental challenge with homologous papillomavirus and cross-reactive epitopes are present in HPV L2. To assess L2-specific cross-neutralization of HPV genotypes, sheep were immunized with purified, bacterially expressed HPV6, 16, or 18 L2. In addition to neutralizing the homologous HPV type in vitro, antisera to each HPV L2 also cross-neutralized both heterologous HPV types. This suggests that unlike VLP-based prophylactic HPV vaccines, an L2 polypeptide vaccine may provide broad-spectrum protection.

Purpose: Persistent infection with oncogenic human papillomaviruses (HPV) plays a central etiologic role in the development of squamous carcinomas of the cervix and their precursor lesions, cervical intraepithelial neoplasias (CIN). We carried out a prospective observational cohort study evaluating known, quantifiable prognostic variables of clinical behavior in women with high-grade cervical lesions. Experimental Design: Our study cohort included healthy women with high-grade cervical lesions (CIN2/3) with residual visible lesions after colposcopically directed biopsy. We prospectively followed 100 women over 15 weeks before standard resection. HPV typing was done using PCR and a reverse line blot detection method. Results: The rate of spontaneous histologic regression, defined as (CIN1 or less at resection) was 28%. The overall rate of HPV infection was 100%. HPV16 was identified in 68% of the lesions. Women with HPV16 only were significantly less likely to regress, compared with women with HPV types other than HPV16 (odds ratio, 0.342; 95% confidence interval, 0.117-0.997; P = 0.049). In the cohort with HPV16 only, patients who had an HLA*A201 allele had similar outcomes to those who did not carryA201. However, among patients with HPV types other than HPV16, the HLA*A201 allele interaction was significant; patients with HLA*A201 were the least likely to resolve. Conclusions: CIN2/3 lesions associated with HPV16 alone are significantly less likely to resolve spontaneously than those caused by other types. Interactions among HPV type, HLA type, and regression rate support a role for HLA-restricted HPV-specific immune responses in determining disease outcome.Persistent infection with a high risk, or oncogenic type of human papillomavirus (HPV) is necessary but not sufficient for the development of most squamous carcinomas of the cervix and their precursor lesions, cervical intraepithelial neoplasia (CIN; ref. 1). CIN1, CIN2, and CIN3 lesions represent a spectrum of disease. Low-grade, or CIN1 lesions, represent a chronic HPV infection, in which HPV DNA is episomal and intact virion production and shedding occur. In women who are immunocompetent, many low-grade, or CIN1 lesions, will nonetheless eventually regress without intervention (1, 2). Reported rates of regression range up to 58% over 24 months (3). A very small percentage (f2%) will progress to high-grade lesions.In contrast, most high-grade, or CIN2/3 lesions are thought to be much more likely to persist than to regress. However, reported rates of spontaneous regression vary from 6% to 50%, depending on diagnostic criteria, and length of follow-up (4). The risk for progression to invasive cancer at 24 months in women with high-grade lesions is f1% to 2%.The mechanisms by which HPV-associated intraepithelial lesions resolve are not well understood. As a prelude to interventional clinical trials in women with biopsy-proven CIN2/3, we carried out a prospective observational cohort study evaluating known, quantifiable prognostic variables in immune ...

Purpose Our preclinical work identified depletion of ATR as a top candidate for topoisomerase 1 (TOP1) inhibitor synthetic lethality and showed that ATR inhibition sensitizes tumors to TOP1 inhibitors. We hypothesized that a combination of selective ATR inhibitor M6620 (previously VX-970) and topotecan, a selective TOP1 inhibitor, would be tolerable and active, particularly in tumors with high replicative stress. Patients and Methods This phase I study tested the combination of M6620 and topotecan in 3-week cycles using 3 + 3 dose escalation. The primary end point was the identification of the maximum tolerated dose of the combination. Efficacy and pharmacodynamics were secondary end points. Results Between September 2016 and February 2017, 21 patients enrolled. The combination was well tolerated, which allowed for dose escalation to the highest planned dose level (topotecan 1.25 mg/m, days 1 to 5; M6620 210 mg/m, days 2 and 5). One of six patients at this dose level experienced grade 4 thrombocytopenia that required transfusion, a dose-limiting toxicity. Most common treatment-related grade 3 or 4 toxicities were anemia, leukopenia, and neutropenia (19% each); lymphopenia (14%); and thrombocytopenia (10%). Two partial responses (≥ 18 months, ≥ 7 months) and seven stable disease responses ≥ 3 months (median, 9 months; range, 3 to 12 months) were seen. Three of five patients with small-cell lung cancer, all of whom had platinum-refractory disease, had a partial response or prolonged stable disease (10, ≥ 6, and ≥ 7 months). Pharmacodynamic studies showed preliminary evidence of ATR inhibition and enhanced DNA double-stranded breaks in response to the combination. Conclusion To our knowledge, this report is the first of an ATR inhibitor-chemotherapy combination. The maximum dose of topotecan plus M6620 is tolerable. The combination seems particularly active in platinum-refractory small-cell lung cancer, which tends not to respond to topotecan alone. Phase II studies with biomarker evaluation are ongoing.

Human papillomavirus type 16 (HPV16) is the primary etiologic agent of cervical carcinoma, whereas bovine papillomavirus type 1 (BPV1) causes benign fibropapillomas. However, the capsid proteins, L1 and L2, of these divergent papillomaviruses exhibit functional conservation. A peptide comprising residues 1 to 88 of BPV1 L2 binds to a variety of cell lines, but not to the monocyte-derived cell line D32, and blocks BPV1 infection of mouse C127 cells. Residues 13 to 31 of HPV16 L2 and BPV1 L2 residues 1 to 88 compete for binding to the cell surface, and their binding, unlike that of HPV16 L1/L2 virus-like particles, is unaffected by heparinase or trypsin pretreatment of HeLa cells. A fusion of HPV16 L2 peptide 13-31 and GFP binds (K d , ϳ1 nM) to ϳ45,000 receptors per HeLa cell. Furthermore, mutation of L2 residues 18 and 19 or 21 and 22 significantly reduces both the ability of the HPV16 L2 13-31-GFP fusion protein to bind to SiHa cells and the infectivity of HPV16 pseudovirions. Antibody to BPV1 L2 peptides comprising residues 115 to 135 binds to intact BPV1 virions, but fails to neutralize at a 1:10 dilution. However, deletion of residues 91 to 129 from L2 abolishes the infectivity of BPV1, but not their binding to the cell surface. In summary, L2 residues 91 to 129 contain epitopes displayed on the virion surface and are required for infection, but not virion binding to the cell surface. Upon the binding of papillomavirus to the cell surface, residues 13 to 31 of L2 interact with a widely expressed, trypsin-and heparinase-resistant cell surface molecule and facilitate infection.The infectious process for most viruses, including papillomavirus, is poorly understood. However, in the last decade, a plethora of primary viral receptors have been identified (reviewed in reference 1). Viruses adhere to the target cells via these primary receptors, but their uptake and transport to the site of viral replication often require interaction with other secondary viral receptors (1).The papillomavirus capsid comprises two genetically unrelated viral proteins called L1 and L2 that surround the ϳ8-kb histone-bound, closed circular viral genomic DNA (14). Expression of the major capsid protein L1 results in Tϭ7 viruslike particles (VLPs) formed from 72 petameric L1 capsomers (21, 29). Three-dimensional image reconstructions and the ϳ30:1 ratio of L1 and L2 in native bovine papillomavirus type 1 (BPV1) suggest that the L2 minor capsid protein is located in the center of the pentavalent capsomers at the virion vertices (46). Both L1 and L2 are necessary for efficient production of infectious viruses in vivo, with L2 functioning in both encapsidation and the infectious process (36, 37, 52).Papillomaviruses bind via L1 to cells derived from a wide variety of tissues and species (34, 40). While papillomavirus pseudovirions lacking L2 are infectious (45), recent reports suggest that L2 also can bind to the cell surface, resulting in its internalization (28), and that L2 is critical to the infectious process (36, 47). Furthermore, ant...