Ustekinumab for the treatment of moderate-to-severe plaque psoriasis in paediatric patients (≥ 6 to < 12 years of age): efficacy, safety, pharmacokinetic and biomarker results from the open-label CADMUS Jr study.

BACKGROUND: Limited options are available for treatment of paediatric psoriasis. OBJECTIVES: To evaluate the efficacy and safety of ustekinumab in paediatric patients with psoriasis (≥ 6 to < 12 years of age). METHODS: CADMUS Jr, a phase III, open-label, single-arm, multicentre study, evaluated ustekinumab in paediatric patients with moderate-to-severe plaque psoriasis. Patients received weight-based dosing of ustekinumab (< 60 kg: 0·75 mg kg-1 ; ≥ 60 to ≤ 100 kg: 45 mg; > 100 kg: 90 mg) administered by subcutaneous injection at weeks 0 and 4, then every 12 weeks through week 40. Study endpoints (all at week 12) included the proportions of patients achieving a Physician's Global Assessment score of cleared/minimal (PGA 0/1) and ≥ 75%/90% improvement in Psoriasis Area and Severity Index (PASI 75/90), and change in Children's Dermatology Life Quality Index (CDLQI). Serum ustekinumab concentrations, antidrug antibodies and cytokine levels were measured through week 52. Safety was evaluated through week 56. RESULTS: In total, 44 patients (median age 9·5 years) received at least one dose of ustekinumab. Three patients discontinued the study agent through week 40. At week 12, 77% of patients achieved PGA 0/1, 84% achieved PASI 75 and 64% achieved PASI 90 response. The mean change in CDLQI was -6·3. Trough serum ustekinumab concentrations reached steady state at weeks 28-52. The incidence of antidrug antibodies was 10% (n = 4). Mean serum concentrations of interleukin-17A/F and interleukin-22 were significantly reduced at weeks 12 and 52. Overall, 34 patients (77%) had at least one adverse event and three (7%) had a serious adverse event. CONCLUSIONS: Ustekinumab effectively treated moderate-to-severe psoriasis in paediatric patients, and no new safety concerns were identified. What is already known about this topic? Ustekinumab is approved for use in adolescents (≥ 12 to < 18 years of age) and adults (≥ 18 years) with moderate-to-severe psoriasis. What does this study add? Ustekinumab effectively treats moderate-to-severe psoriasis in paediatric patients (≥ 6 to < 12 years of age), with no new safety concerns. Linked Comment: Reich. Br J Dermatol 2020; 183:606-607.

Safety of guselkumab in patients with moderate-to-severe psoriasis treated through 100 weeks: a pooled analysis from the randomized VOYAGE 1 and VOYAGE 2 studies.

BACKGROUND: Long-term evaluation is required to confirm the safety profile of newer biologic agents. OBJECTIVES: To report on pooled safety data from the ongoing VOYAGE 1 (NCT02207231) and VOYAGE 2 (NCT02207244) trials through 100 weeks of follow-up. METHODS: Patients were randomized to either guselkumab 100 mg at weeks 0 and 4 and every 8 weeks thereafter; placebo at weeks 0, 4, 12 followed by guselkumab 100 mg at weeks 16 and 20 and every 8 weeks thereafter; or adalimumab 80 mg at week 0, 40 mg at week 1, and 40 mg every 2 weeks thereafter. Patients who received adalimumab crossed over to guselkumab at week 52 (VOYAGE 1) and at/after week 28 based on clinical response (VOYAGE 2). Open-label extensions, in which all patients received guselkumab, started at week 52 (VOYAGE 1) and week 76 (VOYAGE 2). Rates of adverse events (AEs) per 100 patient-years (PYs) are presented through 100 weeks of follow-up. RESULTS: Through week 52, observed rates for guselkumab- and adalimumab-treated patients, respectively, were 262·45 per 100 PYs and 328·28 per 100 PYs for AEs, 6·20 per 100 PYs and 7·77 per 100 PYs for serious AEs (SAEs), 1·22 per 100 PYs and 1·79 per 100 PYs for serious infections (SIs), 0·28 per 100 PYs and 0·40 per 100 PYs for malignancies other than nonmelanoma skin cancers (NMSCs), 0·56 per 100 PYs and 0·40 per 100 PYs for NMSCs, and 0·47 per 100 PYs and 0·40 per 100 PYs for major adverse cardiovascular events (MACEs). Rates among patients treated with guselkumab through week 52 and week 100, respectively, were 262·45 per 100 PYs and 210·41 per 100 PYs for AEs, 6·20 and 6·29 per 100 PYs, for SAEs, 1·22 per 100 PYs and 1·06 per 100 PYs for SIs, 0·28 per 100 PYs and 0·38 per 100 PYs for malignancies, 0·56 per 100 PYs and 0·39 per 100 PYs for NMSCs, and 0·47 per 100 PYs and 0·38 per 100 PYs for MACEs. Among patients treated with adalimumab, rates of AEs, SAEs, SIs, malignancies, NMSCs, and MACEs showed some variability before and after crossover to guselkumab, although no new safety signals were noted after crossover. CONCLUSIONS: The safety profile for guselkumab remains favourable through 100 weeks of treatment in patients with moderate-to-severe psoriasis.

Patient-reported symptoms and signs of moderate-to-severe psoriasis treated with guselkumab or adalimumab: results from the randomized VOYAGE 1 trial.

BACKGROUND: How patients experience the symptoms/signs of psoriasis is highly relevant for assessing treatment response. OBJECTIVES: Compare outcomes with guselkumab, placebo and adalimumab utilizing the novel, validated Psoriasis Symptoms and Signs Diary (PSSD). METHODS: VOYAGE 1 is an ongoing, phase III, double-blinded, controlled trial of patients with moderate-to-severe psoriasis. Patients were randomized to guselkumab 100 mg every 8 weeks; placebo-to-guselkumab 100 mg every 8 weeks; or adalimumab 40 mg every 2 weeks. The PSSD was self-administered to assess symptoms (i.e. itch, skin tightness, burning, stinging and pain) and signs (i.e. dryness, cracking, scaling, shedding/flaking, redness and bleeding) of psoriasis (0-10 [absent-to-worst-imaginable]) every 24 h. Symptom and sign summary scores were derived (0-100) based on average scores of the individual symptoms and signs. Proportions of patients with clinically meaningful improvements and symptom- and sign-free scores of 0 were evaluated across treatment groups at weeks 16, 24 and 48. RESULTS: At baseline, 652 of 837 randomized patients had PSSD scores. The proportion of patients achieving clinically meaningful improvements in PSSD summary scores was significantly higher in the guselkumab group compared with the placebo group at week 16 (P < 0.001) and compared with the adalimumab group at weeks 24 (P = 0.002) and 48 (P < 0.001). The proportions of patients achieving PSSD symptom and sign summary scores of 0 (i.e. symptom- and sign-free) were significantly higher for guselkumab vs. placebo at week 16 and vs. adalimumab at weeks 24 and 48 (all P < 0.001). CONCLUSIONS: Based on PSSD scores, greater improvements in symptoms and signs of psoriasis were reported by patients treated with guselkumab compared with placebo at week 16 or adalimumab through 48 weeks.

Efficacy of guselkumab in subpopulations of patients with moderate-to-severe plaque psoriasis: a pooled analysis of the phase III VOYAGE 1 and VOYAGE 2 studies.

BACKGROUND: Significant advances have been made in the treatment of moderate-to-severe plaque psoriasis with biological therapies; however, these agents may not work equally in all populations. OBJECTIVES: To evaluate the efficacy of guselkumab in patient subgroups with moderate-to-severe psoriasis from the pooled guselkumab VOYAGE 1 and VOYAGE 2 phase III studies. METHODS: Using data from the pooled VOYAGE 1 and VOYAGE 2 psoriasis studies, analyses were performed to evaluate the consistency of efficacy [Investigator's Global Assessment (IGA) 0/1 (cleared or minimal psoriasis) and IGA 0 (cleared)] across subpopulations defined by demographics, baseline disease characteristics and previous psoriasis treatment. RESULTS: A total of 1829 patients were randomized. Baseline demographics, disease characteristics and previous psoriasis treatment were comparable across treatment groups in the pooled population. Guselkumab, an anti-interleukin (IL)-23 monoclonal antibody that binds to the p19 subunit of IL-23, provided substantial benefit across almost all subpopulations, with greater proportions of patients achieving IGA 0/1 vs. placebo at week 16, and vs. adalimumab (an antitumour necrosis factor monoclonal antibody) at week 24. Patients treated with guselkumab achieved greater efficacy (IGA 0/1 and IGA 0) compared with adalimumab at week 24 across all weight quartiles, most notably among patients weighing ≥ 100 kg. CONCLUSIONS: This analysis demonstrates a high degree of efficacy with guselkumab treatment compared with placebo at week 16 and with adalimumab at week 24 among broad subpopulations of patients with varying baseline demographics, disease characteristics and previous psoriasis treatments.

Efficacy and safety of guselkumab in patients with psoriasis who have an inadequate response to ustekinumab: results of the randomized, double-blind, phase III NAVIGATE trial.

BACKGROUND: Guselkumab, an anti-interleukin-23 monoclonal antibody, has demonstrated significant efficacy in phase III psoriasis trials. OBJECTIVES: To evaluate the efficacy and safety of guselkumab in patients with moderate-to-severe plaque psoriasis who had an inadequate response to ustekinumab. METHODS: In this phase III, randomized, double-blind study, 871 patients received open-label ustekinumab (45 mg or 90 mg) at weeks 0 and 4. At week 16, 268 patients with an inadequate response to ustekinumab [Investigator's Global Assessment (IGA) ≥ 2] were randomized (double-blind) to guselkumab 100 mg or to continue ustekinumab; 585 of 871 patients (67%) with IGA 0/1 at week 16 continued open-label ustekinumab. The primary end point was the number of visits at which randomized patients achieved IGA 0/1 and at least a two-grade improvement (from week 16) from week 28 to week 40. Improvement ≥ 90% or 100% in Psoriasis Area and Severity Index (PASI 90/100) and Dermatology Life Quality Index (DLQI) of 0/1 were also assessed. RESULTS: The mean number of visits at which patients achieved IGA 0/1 and at least a two-grade improvemen (week 28-40) was significantly greater in the guselkumab group vs. the randomized ustekinumab group (1·5 vs. 0·7; P < 0·001); greater proportions of patients in the guselkumab group achieved IGA 0/1 and at least a two-grade improvement at week 28 (31·1% vs. 14·3%; P = 0·001) and week 52 (36·3% vs. 17·3%; P < 0·001). Greater proportions of patients treated with guselkumab achieved PASI 90, PASI 100 and DLQI 0/1 at week 52. After week 16, 64·4% of patients in the guselkumab group and 55·6% in the ustekinumab group had at least one adverse event (AE); infections were the most frequent AE type. Overall, 6·7% (n = 9) of patients in the guselkumab group had at least one serious AE compared with 4·5% (n = 6) for the ustekinumab group. CONCLUSIONS: Patients treated with ustekinumab who did not achieve an IGA of 0/1 by week 16 derived significant benefit from switching to guselkumab.

A multidisciplinary approach to study the reproductive biology of wild prawns.

This work aims to provide deeper knowledge on reproductive biology of P. kerathurus in a multidisciplinary way. Upon 789 examined females, 285 were found inseminated. The logistic equation enabled to estimate the size at first maturity at 30.7 mm CL for female. The Gono-Somatic Index (GSI) showed a pronounced seasonality, ranged from 0.80 ± 0.34 to 11.24 ± 5.72. Histological analysis highlighted five stages of ovarian development. Gonadal fatty acids analysis performed with gas chromatograph evidenced a pronounced seasonal variation; total lipids varied from 1.7% dry weight (dw) in Winter, to 7.2% dw in Summer. For the first time, a chemometric approach (Principal Component Analysis) was applied to relate GSI with total lipid content and fatty acid composition of gonads. The first two components (PC1 and PC2) showed that seasonality explained about 84% of the variability of all data set. In particular, in the period February-May, lipids were characterized by high PUFAs content, that were probably utilized during embryogenesis as energy source and as constituent of the cell membranes. During the summer season, gonads accumulated saturated FAs, that will be used during embryogenesis and early larval stages, while in the cold season total lipids decreased drastically and the gonad reached a quiescent state.

Efficacy and safety of ustekinumab in Japanese patients with severe atopic dermatitis: a randomized, double-blind, placebo-controlled, phase II study.

BACKGROUND: Ustekinumab, a fully human monoclonal antibody against interleukin-12/23, may potentially be effective for severe atopic dermatitis (AD) treatment. OBJECTIVES: To evaluate efficacy and safety of ustekinumab 45 mg and 90 mg in patients with severe AD. METHODS: In this randomized, placebo-controlled, phase II study, Japanese patients (aged 20-65 years) with severe or very severe AD entered a 12-week double-blind treatment period during which they received (1 : 1 : 1) ustekinumab 45 mg, 90 mg or placebo subcutaneous injections at weeks 0 and 4, with follow-up until week 24. The primary efficacy end point was percentage change from baseline in Eczema Area and Severity Index (EASI) score at week 12. Major secondary efficacy end points included the proportion of patients achieving EASI 50, EASI 75, Investigator's Global Assessment score 0-1, change from baseline Atopic Dermatitis Itch Scale and Dermatology Life Quality Index. RESULTS: A total of 79 patients were randomized [ustekinumab 45 mg (n = 24), 90 mg (n = 28), placebo (n = 27)]. Ustekinumab treatment showed nonsignificant improvement in least square mean change from baseline EASI score at week 12 [45 mg: -38·2%, 95% confidence interval (CI) -21·02-19·51; P < 0·94 and 90 mg: -39·8%, 95% CI -21·84-17·14; P < 0·81] vs. placebo (-37·5%). A nonsignificant improvement in major secondary efficacy end points was observed in both ustekinumab groups vs. placebo. The most common treatment-emergent adverse events were nasopharyngitis and worsened AD (higher in placebo vs. ustekinumab groups). CONCLUSIONS: Ustekinumab 45 mg and 90 mg did not demonstrate meaningful efficacy in Japanese patients with severe AD. The treatment was generally well tolerated.

Acid-sensing ion channels and transient-receptor potential ion channels in zebrafish taste buds.

Sensory information from the environment is required for life and survival, and it is detected by specialized cells which together make up the sensory system. The fish sensory system includes specialized organs that are able to detect mechanical and chemical stimuli. In particular, taste buds are small organs located on the tongue in terrestrial vertebrates that function in the perception of taste. In fish, taste buds occur on the lips, the flanks, and the caudal (tail) fins of some species and on the barbels of others. In fish taste receptor cells, different classes of ion channels have been detected which, like in mammals, presumably participate in the detection and/or transduction of chemical gustatory signals. However, since some of these ion channels are involved in the detection of additional sensory modalities, it can be hypothesized that taste cells sense stimuli other than those specific for taste. This mini-review summarizes current knowledge on the presence of transient-receptor potential (TRP) and acid-sensing (ASIC) ion channels in the taste buds of teleosts, especially adult zebrafish. Up to now ASIC4, TRPC2, TRPA1, TRPV1 and TRPV4 ion channels have been found in the sensory cells, while ASIC2 was detected in the nerves supplying the taste buds.

Induction of mild enterocolitis in zebrafish Danio rerio via ingestion of Vibrio anguillarum serovar O1.

Vibrio anguillarum is the etiological agent of a fatal hemorrhagic disease known as vibriosis that affects a wide range of fish species, causing severe economic losses. Several investigations have been carried out to elucidate the virulence mechanisms of this pathogen and to develop rapid detection techniques and effective disease-prevention strategies. The aim of our study was to evaluate the most effective way to induce mild enteritis in a fish model, in order to allow further applications. The experiments were carried out using 2 methods of administration of V. anguillarum serotype O1 to adult zebrafish Danio rerio: via intraperitoneal injection and via ingestion of infected Artemia nauplii. The results showed that the intraperitoneal administration often caused massive fish death due to severe systemic involvement. In our experiments, the effect of intraperitoneal infection was evident 48 h post infection, with cumulative mortality within 7 d post infection with severe histopathological changes in kidney hematopoietic tissue and in the intestine. In contrast, oral infection via Artemia did not show systemic involvement and only a moderate degree of inflammatory influx of the mucosa, a partial recovery at 12 d post infection, and no mortality. For these reasons, oral infection with live food appears to be the most effective method to induce mild enteritis with a local inflammatory response.

The transcriptional activation domain of VP16 is required for efficient infection and establishment of latency by HSV-1 in the murine peripheral and central nervous systems.

The herpes simplex virus (HSV) transactivator VP16 is a structural component of the virion that activates immediate-early viral gene expression. The HSV-1 mutant in1814, which contains a 12-bp insertion that compromises the transcriptional function of VP16, replicated to a low level if at all in the trigeminal ganglia of mice (I. Steiner, J. G. Spivack, S. L. Deshmane, C. I. Ace, C. M. Preston, and N. W. Fraser (1990). J. Virol. 64, 1630-1638; Valyi-Nagy et al., unpublished data). However, in1814 did establish a latent infection in the ganglia after corneal inoculation from which it could be reactivated. In this study, several HSV-1 strains were constructed with deletions in the VP16 transcriptional activation domain. These viruses were viable in cell culture, although some were significantly reduced in their ability to initiate infection. A deletion mutant completely lacking the activation domain of VP16 (RP5) was unable to replicate to any detectable level or to efficiently establish latent infections in the peripheral and central nervous systems of immunocompetent mice. However, similar to in1814, RP5 formed a slowly progressing persistent infection in immunocompromised nude mice. Thus RP5 is severely neuroattenuated in the murine model of HSV infection. However, the activation domain of VP16 is not essential for replication in the nervous system, since we observed a slow progressive infection persisting in the absence of an immune response.

A neuroattenuated ICP34.5-deficient herpes simplex virus type 1 replicates in ependymal cells of the murine central nervous system.

Herpes simplex virus type 1 (HSV-1) variant 1716 is deleted in the gene encoding ICP34.5 and is neuroattenuated after intracranial inoculation of mice. Although the mechanism of attenuation is unclear, this property has been exploited to eliminate experimental brain tumours. Previously, it was shown that infectious 1716 was recoverable for up to 3 days after intracranial inoculation suggesting that there may be limited replication in the central nervous system (CNS). Here it is demonstrated that 1716 replicates in specific cell types (predominantly CNS ependymal cells) of BALB/c mice, using immunohistochemical, immunofluorescence, in situ hybridization and virus titration studies. While 1716-infected mice exhibited no overt signs of encephalitis, histological analysis showed a persistent loss of the ependymal lining. Thus, although ICP34.5-deficient viruses are neuroattenuated, they do retain the ability to replicate in and destroy the ependyma of the murine CNS. A detailed understanding of the mechanism(s) of neuroattenuation and limited replication could lead to the rational design of safe HSV vectors for cancer and gene therapy in the CNS.

Herpes simplex virus 1716, an ICP 34.5 null mutant, is unable to replicate in CV-1 cells due to a translational block that can be overcome by coinfection with SV40.

Herpes simplex virus (HSV) mutants lacking the gene encoding infected cell protein (ICP) 34.5 exhibit an attenuated phenotype in models of pathogenesis and have been used for experimental cancer therapy. Recently it was shown that the HSV ICP 34.5 protein functions to prevent the host cell-induced double-stranded RNA-activated protein kinase (PKR)-dependent translational block that normally occurs during virus infection. We now report that an HSV ICP 34.5 mutant called HSV-1716 is unable to replicate in the simian kidney cell-derived line CV-1, due to a translational block. Moreover, we find that this block can be overcome by simian virus 40 (SV40). This has been shown directly by infecting CV-1 cells with SV40 and HSV-1716 simultaneously, and indirectly via HSV-1716 infection of COS-1 cells (CV-1 cells transformed by an origin-defective mutant of SV40 that codes for wild-type T antigen). The translational block is restored when infections are done in the presence of the phosphatase inhibitor okadaic acid. These results support, but do not directly prove, contentions that HSV ICP 34.5 interacts with the PKR pathway to restore translation in non-permissive cells, and that SV40 large T antigen has a similar functional role, but acts downstream of the site of ICP 34.5 interaction (eIF2alpha) in the pathway. Study of this CV-1/COS-1 system should allow further clarification of the virus-host interactions that underlie the restricted replication of HSV-1 ICP 34.5 gene null mutants.

Treatment of experimental subcutaneous human melanoma with a replication-restricted herpes simplex virus mutant.

Modified, non-neurovirulent herpes simplex viruses (HSV) have shown promise for the treatment of brain tumors, including intracranial melanoma. In this report, we show that HSV-1716, an HSV-1 mutant lacking both copies of the gene coding-infected cell protein 34.5 (ICP 34.5), can effectively treat experimental subcutaneous human melanoma in mice. In vitro, HSV-1716 replicated in all 26 human melanoma cell lines tested, efficiently lysing the cells. Therapeutic infection of subcutaneous human melanoma nodules with HSV-1716 led to viral replication that was restricted to tumor cells by immunohistochemistry. Moreover, HSV-1716 treatment significantly inhibited progression of preformed subcutaneous human melanoma nodules in SCID mice and caused complete regression of some tumors. This work expands the potential scope of HSV-1-based cancer therapy.

Use of a "replication-restricted" herpes virus to treat experimental human malignant mesothelioma.

Modified, nonneurovirulent herpes simplex viruses (HSVs) have shown promise in the treatment of brain tumors. However, HSV-1 can infect and lyse a wide range of cell types. In this report, we show that HSV-1716, a mutant lacking both copies of the gene coding ICP-34.5, can effectively treat a localized i.p. malignancy. Human malignant mesothelioma cells supported the growth of HSV-1716 and were efficiently lysed in vitro. i.p. injection of HSV-1716 into animals with established tumor nodules reduced tumor burden and significantly prolonged survival in an animal model of non-central nervous system-localized human malignancy without dissemination or persistence after i.p. injection into SCID mice bearing human tumors. These findings suggest that this virus may be efficacious and safe for use in localized human malignancies of nonneuronal origin such as malignant mesothelioma.

Herpes simplex 1716--an ICP 34.5 mutant--is severely replication restricted in human skin xenografts in vivo.

HSV-1716 is a replication-restricted, neuroattenuated ICP 34.5 gene mutant of herpes simplex virus type 1 (HSV-1). Because of the attenuated phenotype of ICP 34.5 mutants in rodent models of HSV disease, they have been promoted as potential vaccine strains and gene therapy vectors and have been used by us and others as therapeutic agents for the treatment of experimental malignant tumors. However, all data on the phenotype of HSV-1716 and other ICP 34.5 mutants are from animal model systems, while humans are the natural hosts of HSV-1. To achieve an initial characterization of the phenotype of 1716 in human tissue, we have studied its replication in mature human skin xenografts on SCID mice. We find that replication of 1716 is severely restricted in such human skin grafts relative to both parental wild-type HSV-1 strain 17+ and the HSV-1716 revertant virus 1716R, in which the 759-bp ICP 34.5 gene deletions have been repaired. Moreover, the replication of both 1716 and 17+ is significantly better in the human skin grafts than it is in mouse skin. The implications of these findings are discussed.

Therapy of experimental human brain tumors using a neuroattenuated herpes simplex virus mutant.

BACKGROUND: Engineered herpes simplex virus (HSV) strains previously have been shown to offer a potential therapeutic alternative to conventional treatment modalities for brain tumors. Because HSV Type 1 strain 1716 has a deletion in the gamma 34.5 neurovirulence gene that renders it avirulent in the mouse central nervous system, we have assessed its potential to induce selective lysis of tumor cells versus neurons in vitro and in vivo. EXPERIMENTAL DESIGN: To do this, we studied parental HSV-1 strain 17+ and strain 1716 using human embryonal carcinoma cells (NT2 cells). These cells resemble neuronal progenitor cells and can be induced to differentiate into neurons (NT2N) with retinoic acid. Intracerebral grafts of NT2 cells into the brains of nude mice resulted in lethal brain tumors, and grafts of NT2N cells resulted in the integration of NT2N cells. RESULTS: In vitro studies showed that strain 1716 replicates in and spreads on monolayers of NT2 cells but not in NT2N cells. In vivo, strain 1716 replicated preferentially in NT2 tumors as evidenced by immunohistochemical staining for viral antigens, by in situ hybridization for HSV-specific transcripts, and by titration of virus from brains with tumor after intracranial injection of the virus into these mice. The temporal regression of NT2 tumors in mice treated with strain 1716 was demonstrated in vivo by magnetic resonance imaging. Electron microscopy and studies of DNA fragmentation suggested that regression of NT2 brain tumors in strain 1716-treated mice was mainly caused by a nonapoptotic, lytic mode of cell death. Finally, strain 1716-treated NT2 tumor-bearing mice survived more than twice as long as mock-treated tumor-bearing mice, and these differences in survival (25 vs. 9 weeks) were statistically significant (p < 0.03). CONCLUSIONS: We conclude from these studies that strain 1716 induces regression of human neural tumors established in the brains of nude mice, resulting in their prolonged survival.

Treatment of experimental intracranial murine melanoma with a neuroattenuated herpes simplex virus 1 mutant.

Brain metastases occur commonly in the setting of a variety of human cancers. At present, such cases are invariably fatal and highlight a need for research on new therapies. We have developed a mouse brain tumor model utilizing the Harding-Passey melanoma cell line injected intracranially into C57Bl/6 mice. Tumors develop in 100% of the mice and can be detected by magnetic resonance imaging as early as 5 days post cell injection. Death from tumor progression occurs between 12 and 16 days post cell injection. Stereotactic injection of the neuroattenuated HSV-1 strain 1716 into brain tumors 5 or 10 days postinjection of the melanoma cells results in a statistically significant increase in the time to development of neurological symptoms and in complete tumor regression and the long-term survival of some treated animals. Moreover, viral titration studies and immunohistochemistry suggest that replication of this virus is restricted to tumor cells and does not occur in the surrounding brain tissue. These results suggest that HSV-1 mutant 1716 shows particular promise for use as a therapeutic agent for the treatment of brain tumors.

A thymidine kinase-negative HSV-1 strain establishes a persistent infection in SCID mice that features uncontrolled peripheral replication but only marginal nervous system involvement.

A detailed knowledge of the pathogenesis of infections caused by thymidine-kinase (TK)-deficient herpes simplex virus type 1 (HSV-1) strains is important because such mutants can arise during treatment of HSV infections with acyclovir--especially in immunocompromised patients--and also because TK-negative mutants may become useful for the therapy of intracranial tumors. In this work, we studied the pathogenesis of a genetically engineered TK-negative HSV-1 strain dlsptk, in SCID mice (mice with severe combined immunodeficiency) after corneal infection. We found that dlsptk established a persistent infection that kills SCID mice within 80.2 +/- 21.3 days. The cause of death seemed to be related to uncontrolled viral replication in the superficial and deep facial tissues of the animals. Viremia probably did not occur, as judged by the inability to detect infectious virus and viral gene expression in various internal organs. However, the virus did reach the nervous system, most probably by axonal transport from the primary site of the infection. Virus-specific DNA reached low but detectable levels in the trigeminal ganglia and the brainstems by 7 days p.i. and remained at low levels for up to 50 days p.i. as determined by spot blot analysis. By in situ hybridization and immunostaining we determined that, in some of the neurons of the trigeminal ganglia infected by the virus, viral latency was established. However, our results suggested that in other infected neurons viral replication occurred and virus spread to surrounding nonneuronal cells and to the central nervous system. This work provides a new model in which the pathogenesis of infections caused by TK-deficient HSV strains in immunocompromised hosts can be effectively studied and which may also help to identify the potential side effects of the therapy of intracranial tumors with TK-negative HSV strains.

Expression of functional cell surface C1-inactivator by U937 cells.

We have previously shown that the human monocyte-like cell line U937 synthesizes C1-INA and expresses cell surface C1-INA. In this report we provide evidence that this surface-expressed C1-INA is functionally active. Intact U937 cells demonstrated functional C1-INA activity in a hemolytic assay. This activity was blocked when the cells were incubated with monospecific antibody to C1-INA, and was not detectable in cell-free supernatants of U937 cells. SDS-PAGE analysis of radiolabeled U937 cell surface proteins purified by anti-C1-INA affinity chromatography revealed two distinct bands. One protein had a Mr of 105 kDa identical to plasma C1-INA, and the second had a Mr of 200 kDa. We were unable to determine the identity of the 200 kDa protein by Western blotting with anti-C1-INA. However, the possibility exists that this 200 kDa molecule may represent a C1-INA receptor, a dimeric form of C1-INA, or an unrelated cell surface protein with affinity for C1-INA. Furthermore, we show that treatment of U937 cells with phorbol ester resulted in an increase in the percentage of cells expressing surface C1-INA. These results suggest that U937 cells express functional cell surface C1-INA, which could function in vivo to protect these human tumor cells from lysis by host complement.