Thalidomide delayed the ability of 4T1 cells to amass into tumors in Balb/c mice.

Thalidomide (Thal) can suppress the growth of established, as well as explanted tumors in mice. We wanted to determine if it could suppress the ability of tumor cells to assemble and establish a primary tumor at the injection site. Using the mouse 4T1 mammary tumor model, we fed Thal to mice for 4 days, then injected 10(5) 4T1 cells into the interscapular region of Balb/c mice. After 20 days on treatment with Thal, all seven control mice, fed with meal had tumors ranging from 3 to 93 mm(3) (median 20). Two of the eight mice fed with meal + Thal had no tumors, and the remaining mice had tumors ranging from 2 to 22 mm(3) (median 5). The median volume of the tumors in the control group was significantly more than that of mice treated with Thal (p = 0.03, Mann-Whitney test). In vitro treatment of the 4T1cells with Thal did not inhibit their ability to proliferate, to adhere to plastic, or to bind to Concanavalin-A. Thal caused a marked reduction in the ability of the 4T1 cells to assemble into palpable tumors.

Thalidomide suppressed the growth of 4T1 cells into solid tumors in Balb/c mice in a combination therapy with the oncolytic fusogenic HSV-1 OncdSyn.

PURPOSE: The anti-tumor properties of thalidomide or in combination with an oncolytic herpes virus (OncdSyn) was investigated in a mouse model of human breast cancer. METHODS: To determine if thalidomide could act alone, 4T1 cells were injected into Balb/c mice. Tumors were sized, and the mice were fed chow or chow-containing thalidomide. After 4 days the tumor volumes were compared. To determine if thalidomide could act with the virus, tumors of mice were injected with phosphate buffered saline (PBS), or fed thalidomide with injections of PBS, or fed thalidomide with injections of OncdSyn, or received injections of OncdSyn. RESULTS: Thalidomide alone suppressed tumor growth. The most significant treatment occurred in thalidomide-fed-OncdSyn-injected mice. Compared to PBS controls, there was a significant difference in the number of metastatic nodes in the lungs. CONCLUSIONS: Thalidomide alone delayed tumor growth, but the combination of thalidomide with OncdSyn appeared to produce the best results.

Complete genome analysis and virulence characteristics of the Louisiana West Nile virus strain LSU-AR01.

West Nile virus (WNV) is a member of the Flaviriridae family, which can cause significant morbidity and mortality in birds, horses, and humans. The WNV-LSU-AR01 strain was isolated from a dead blue jay in Louisiana in 2001. Phylogenetic analysis using 75 full WNV genomes revealed that the LSU-AR01 strain belongs to a distinct subclade among the North American strains. The LSU-AR01 strain differed from the NY-99 prototypic strain by 26 nucleotides causing six amino acid changes. An asparagine-to-lysine change was located immediately proximal to a known CD8(+)T cell epitope in NS4B, while a glutamine-to-lysine change was located within a predicted CD8(+)T cell epitope in NS5. The LSU-AR01 strain caused pronounced neuronal necrosis, perivascular cuffing and gliosis in comparison to the NY-99-infected mice. These results suggest that the previously identified Connecticut strains may contain highly neurovirulent strains such as the LSU-AR01 that have spread in North America.

Recombinant vesicular stomatitis virus-based west Nile vaccine elicits strong humoral and cellular immune responses and protects mice against lethal challenge with the virulent west Nile virus strain LSU-AR01.

Vesicular stomatitis virus (VSV) has been extensively utilized as a viral vector system for the induction of protective immune responses against a variety of pathogens. We constructed recombinant VSVs specifying either the Indiana or Chandipura virus G glycoprotein and expressing the West Nile virus (WNV) envelope (E) glycoprotein. Mice were intranasally vaccinated using a prime (Indiana)-boost (Chandipura) immunization approach and challenged with the virulent WNV-LSU-AR01. Ninety-percent (9 of 10) of the vaccinated mice survived as compared to 10% of the mock-vaccinated mice after WNV lethal challenge. Histopathological examination of brain tissues revealed neuronal necrosis in mock-vaccinated mice but not in vaccinated mice, and vaccinated, but not mock-vaccinated mice developed a strong neutralizing antibody response against WNV. Extensive immunological analysis using polychromatic flow cytometry staining revealed that vaccinated, but not mock-vaccinated mice developed robust cellular immune responses as evidenced by up-regulation of CD4(+) CD154(+) IFNgamma(+) T cells in vaccinated, but not mock-vaccinated mice. Similarly, vaccinated mice developed robust E-glycoprotein-specific CD8(+) T cell immune responses as evidenced by the presence of a high percentage of CD8(+) CD62L(low) IFNgamma(+) cells. In addition, a sizeable population of CD8(+) CD69(+) cells was detected indicating E-specific activation of mature T cells and CD4(+) CD25(+) CD127(low) T regulatory (T reg) cells were down-regulated. These results suggest that VSV-vectored vaccines administered intranasally can efficiently induce protective humoral and cellular immune responses against WNV infections.

Herpes simplex virus type-1(HSV-1) oncolytic and highly fusogenic mutants carrying the NV1020 genomic deletion effectively inhibit primary and metastatic tumors in mice.

BACKGROUND: The NV1020 oncolytic herpes simplex virus type-1 has shown significant promise for the treatment of many different types of tumors in experimental animal models and human trials. Previously, we described the construction and use of the NV1020-like virus OncSyn to treat human breast tumors implanted in nude mice. The syncytial mutation gKsyn1 (Ala-to-Val at position 40) was introduced into the OncSyn viral genome cloned into a bacterial artificial chromosome using double-red mutagenesis in E. coli to produce the OncdSyn virus carrying syncytial mutations in both gB(syn3) and gK(syn1). RESULTS: The OncdSyn virus caused extensive virus-induced cell fusion in cell culture. The oncolytic potential of the OncSyn and OncdSyn viruses was tested in the highly metastatic syngeneic mouse model system, which utilizes 4T1 murine mammary cancer cells implanted within the interscapular region of Balb/c mice. Mice were given three consecutive intratumor injections of OncSyn, OncdSyn, or phosphate buffered saline four days apart. Both OncSyn and OncdSyn virus injections resulted in significant reduction of tumor sizes (p < 0.05) compared to control tumors. Virus treated mice but not controls showed a marked reduction of metastatic foci in lungs and internal organs. Mouse weights were not significantly impacted by any treatment during the course of the entire study (p = 0.296). CONCLUSION: These results show that the attenuated, but highly fusogenic OncSyn and OncdSyn viruses can effectively reduce primary and metastatic breast tumors in immuncompetent mice. The available bac-cloned OncSyn and OncdSyn viral genomes can be rapidly modified to express a number of different anti-tumor and immunomodulatory genes that can further enhance their anti-tumor potency.

Effective treatment of human breast tumor in a mouse xenograft model with herpes simplex virus type 1 specifying the NV1020 genomic deletion and the gBsyn3 syncytial mutation enabling high viral replication and spread in breast cancer cells.

A new oncolytic and fusogenic herpes simplex virus type 1 (HSV-1) was constructed on the basis of the wildtype HSV-1(F) strain. To provide for safety and tumor selectivity, the virus carried a large deletion including one of the two alpha4, gamma(1)34.5, alpha0 genes and the latency-associated transcript region. The gamma(1)34.5 gene, a major neurovirulence factor, was replaced by a gene cassette constitutively expressing the red fluorescent protein gene. Homologous recombination was used to transfer the fusogenic gBsyn3 mutation to the viral genome to produce the OncSyn virus. OncSyn causes extensive virus-induced cell fusion (syncytia) and replicates to higher titers than the parental Onc and HSV-1(F) strains in breast cancer cells. Biochemical analysis revealed that the OncSyn virus retains a stable genome and expresses all major viral glycoproteins. A xenograft mouse model system using MDA-MB-435S-luc (MM4L) human breast cancer cells constitutively expressing the luciferase gene implanted within the interscapular region of animals was used to test the ability of the virus to inactivate breast tumor cells in vivo. Seventy-two mice bearing MM4L breast cancer xenografts were randomly divided into three groups and given two rounds of three consecutive intratumoral injections of OncSyn, inactivated OncSyn, or phosphate-buffered saline 3 days apart. A single round of virus injections resulted in a drastic reduction of tumor sizes (p

Protective immunity against lethal HSV-1 challenge in mice by nucleic acid-based immunisation with herpes simplex virus type-1 genes specifying glycoproteins gB and gD.

DNA-based vaccines were employed to assess protective immunity against herpes simplex virus in experimental infections of hairless (strain SKH1) and BALB/c mice. Mice were vaccinated with plasmids containing the herpes simplex virus type-1 (HSV-1) glycoprotein B (gB) or D (gD) genes under the human cytomegalovirus immediate-early promoter control. Vaccines were injected intramuscularly (i.m.) or intraperitoneally (i.p.) as purified DNA alone or as formulations supplemented with different non-ionic block copolymers. Antibody responses were assessed by immunofluorescence and radio-immunoprecipitation assays. Mice inoculated with either gB or gD plasmid, alone or with non-ionic block copolymers CRL 1029 and CRL 1190, produced high levels of antibodies specific for gB or gD. Three weeks after the last vaccination, mice were challenged with a clinical HSV-1 isolate (ABGK-1) by inoculation of a shaved and subsequently scarified area between the third and fourth lumbar vertebrae. Mice immunised with either gD or gB plasmid alone or mixed with copolymers were protected against lethal HSV-1 challenge when immunisation was performed via the i.m. route. Immunisations given via the i.p. route induced humoral responses in some mice and protected the animals against lethal HSV-1 challenge only when the formulations contained copolymers. The BALB/c mouse model was shown to be as good a model as the hairless mouse model.