Biomedical subjects

Michela Spadaro

Publications and source records attributed to Michela Spadaro.

10 recordsLinked to original sources

PubMed2006

Immunosurveillance of Erbb2 carcinogenesis in transgenic mice is concealed by a dominant regulatory T-cell self-tolerance.

To assess the role of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells in overcoming immunosurveillance of Erbb2 (HER-2/neu) mammary lesions, we studied the effects of their sustained removal in BALB/c female mice made transgenic for the rat Erbb2 (r-Erbb2) oncogene (BALB-neuT mice), which develop multiple mammary carcinomas. During the progression of these lesions, Treg cells expand in the spleen, tumor draining lymph nodes, and tumors. Repeated administration of anti-CD25 antibodies extends tumor-free survival, reduces carcinoma multiplicity, and leads to the manifestation of a natural antibody and CTL-mediated reactivity against r-Erbb2. Loss of Foxp3(+) Treg cells during anti-CD25 treatment remarkably caused the disappearance of Gr1(+) immature myeloid cells, suggesting a cross-talk between these two inhibitory immune cell types. Treg cell expansion associated with r-Erbb2 overexpression may be seen as a physiologic response to dampen the immune reaction elicited by local anomalous overexpression of a self-antigen.

Animals↗

PubMed2006

Timely DNA vaccine combined with systemic IL-12 prevents parotid carcinomas before a dominant-negative p53 makes their growth independent of HER-2/neu expression.

Double transgenic mice overexpressing the transforming rat HER-2/neu oncogene and the mutated p53, with both dominant-negative and a gain-of-function properties, display early aggressive and metastasizing parotid tumors. Multiple acinar and ductal hyperplasia foci overexpressing the HER-2/neu gene product are evident at wk 5 and progress to poorly differentiated carcinoma by wk 7. Mice die before wk 18 with invasive carcinomas and multiple metastases that no longer express HER-2/neu. A combination of repeated electroporations of plasmids coding for the extracellular and transmembrane domains of the rat HER-2/neu receptor with systemic IL-12 administrations started when the parotids that present diffuse hyperplasia protected all female and 50% of the male mice until the close of the experiment at wk 40. This combined treatment began when multifocal in situ carcinomas that were already present cured 33% of the females and 25% of the males. The most prominent immunologic features associated with the antitumor protection were the production of high titers of anti-HER-2/neu Abs and the nonappearance of cell-mediated cytotoxic reactivity. In conclusion, anti-HER-2/neu vaccination combined with systemic IL-12 control parotid carcinomas as far as p53 mutation makes their growth independent of HER-2/neu expression.

3T3 Cells↗

PubMed2005

Cure of mammary carcinomas in Her-2 transgenic mice through sequential stimulation of innate (neoadjuvant interleukin-12) and adaptive (DNA vaccine electroporation) immunity.

PURPOSE: Whereas neoadjuvant therapy is emerging as a treatment option in early primary breast cancer, no data are available on the use of antiangiogenic and immunomodulatory agents in a neoadjuvant setting. In a model of Her-2 spontaneous mammary cancer, we investigated the efficacy of neoadjuvant interleukin 12 (IL-12) followed by "immune-surgery" of the residual tumor. EXPERIMENTAL DESIGN: Female BALB/c mice transgenic for the rat Her-2 oncogene inexorably develop invasive carcinomas in all their mammary glands by the 23rd week of age. Mice with multifocal in situ carcinomas received four weekly i.p. injections of 100 ng IL-12 followed by a 3-week rest. This course was given four times. A few mice additionally received DNA plasmids encoding portions of the Her-2 receptor electroporated through transcutaneous electric pulses. RESULTS: The protection elicited by IL-12 in combination with two DNA vaccine electroporations kept 63% of mice tumor-free. Complete protection of all 1-year-old mice was achieved when IL-12-treated mice received four vaccine electroporations. Pathologic findings, in vitro tests, and the results from immunization of both IFN-gamma and immunoglobulin gene knockout transgenic mice and of adoptive transfer experiments all show that IL-12 augments the B- and T-cell response elicited by vaccination and slightly decreases the number of regulatory T cells. In addition, IL-12 strongly inhibits tumor angiogenesis. CONCLUSIONS: In Her-2 transgenic mice, IL-12 impairs tumor progression and triggers innate immunity so markedly that DNA vaccination becomes effective at late points in time when it is ineffective on its own.

Animals↗

PubMed2004

Oral lactoferrin inhibits growth of established tumors and potentiates conventional chemotherapy.

In this work, we investigated the anticancer activity of orally administered recombinant human lactoferrin (rhLF) alone and in combination with chemotherapy in tumor-bearing mice. rhLF inhibited the growth of squamous cell carcinoma (O12) tumors in T cell-immunocompromised nu/nu mice by 80% when administered at 1,000 mg/kg (2.9 g/m2) by oral gavage twice daily for 8 days (p < 0.001). Similar activity was observed in syngeneic, immunocompetent BALB/c mice, where orally administered rhLF (1,000 mg/kg, 2.9 g/m2 once daily) halted the growth of mammary adenocarcinoma TUBO. Oral rhLF (200 mg/kg, 0.57 g/m2) was also used alone and in combination with cis-platinum (5 mg/kg) to treat head-and-neck squamous cell carcinoma in a syngeneic murine model. Monotherapy with oral rhLF or cis-platinum caused 61% or 66% tumor growth inhibition over placebo, respectively. Mice receiving both therapies showed 79% growth inhibition, a statistically significant improvement over each drug alone. We then demonstrated that administration of oral rhLF (300 mg/kg, 0.86 g/m2) to tumor-bearing or naive mice resulted in (i) significantly increased production of IL-18 in the intestinal tract, (ii) systemic NK cell activation and (iii) circulating CD8+ T-cell expansion. These data suggest that oral rhLF is an immunomodulatory agent active against cancer as a single agent and in combination chemotherapy, exerting its systemic effect through stimulation of IL-18 and other cytokines in the gut enterocytes. rhLF has been administered orally to 211 people without a single serious drug-related adverse event. Thus, rhLF shows promise as a safe and well-tolerated novel immunomodulatory anticancer agent.

Administration, Oral↗

PubMed2004

Electroporated DNA vaccine clears away multifocal mammary carcinomas in her-2/neu transgenic mice.

The transforming rat Her-2/neu oncogene embedded into the genome of virgin transgenic BALB/c mice (BALB-neuT) provokes the development of an invasive carcinoma in each of their 10 mammary glands. i.m. vaccination with DNA plasmids coding for the extracellular and transmembrane domains of the protein product of the Her-2/neu oncogene started when mice already display multifocal in situ carcinomas temporarily halts neoplastic progression, but all mice develop a tumor by week 43. By contrast, progressive clearance of neoplastic lesions and complete protection of all 1-year-old mice are achieved when the same plasmids are electroporated at 10-week intervals. Pathological findings, in vitro tests, and the results from the immunization of both IFN-gamma and immunoglobulin gene knockout BALB-neuT mice, and of adoptive transfer experiments, all suggest that tumor clearance rests on the combination of antibodies and IFN-gamma-releasing T cells. These findings show that an appropriate vaccine effectively inhibits the progression of multifocal preneoplastic lesions.

Animals↗

PubMed2004

Immunological inhibition of carcinogenesis.

The combination of new information provided by fundamental immunology, along with the refinement of genetic engineering techniques has given scientists the capacity to produce vaccines able to inhibit the growth of most if not every transplantable tumor. However, when faced with already established tumors, vaccines fail to afford any significant protection. Many studies are underway which seek to overcome this gloomy situation. However, another possibility is to follow the indications provided by a large quantity of experimental data and to evaluate the possibility of using immunotherapy to prevent the initial stages of tumor growth. Is it possible to prevent an autologous tumor by means of a vaccination performed before tumor onset? Could antitumor vaccines be a new form of preventive medicine in the wake of Jenner, Pasteur, and other pioneers? In this paper it is our intention to review the results obtained by our laboratory in the attempt to use natural and adaptive immunity in the control of carcinogenesis. Natural immunity boosted by IL-12 and IL-2 significantly hampers the progression of mammary lesions occurring in HER-2/neu transgenic mice genetically predestined to develop lethal mammary carcinomas. Specific immunity elicited by DNA vaccination provides a much stronger inhibition of the development of mammary lesions, and a significant number of transgenic mice are tumor free at 1 year of age. These experimental data suggest the possibility of using immunity as a means of controlling preneoplastic lesions and protecting healthy persons at risk of developing cancer.

Animals↗

PubMed2004

Concordant morphologic and gene expression data show that a vaccine halts HER-2/neu preneoplastic lesions.

While much experimental data shows that vaccination efficiently inhibits a subsequent challenge by a transplantable tumor, its ability to inhibit the progress of autochthonous preneoplastic lesions is virtually unknown. In this article, we show that a combined DNA and cell vaccine persistently inhibits such lesions in a murine HER-2/neu mammary carcinogenesis model. At 10 weeks of age, all of the ten mammary gland samples from HER-2/neu-transgenic mice displayed foci of hyperplasia that progressed to invasive tumors. Vaccination with plasmids coding for the transmembrane and extracellular domain of rat p185neu followed by a boost with rp185neu+ allogeneic cells secreting IFN-gamma kept 48% of mice tumor free. At 22 weeks, their mammary glands were indistinguishable from those of 10-week-old untreated mice. Furthermore, the transcription patterns of the two sets of glands coincided. Of the 12,000 genes analyzed, 17 were differentially expressed and related to the antibody response. The use of B cell knockout mice as well as the concordance of morphologic and gene expression data demonstrated that the Ab response is the main mechanism facilitating tumor growth arrest. This finding suggests that a new way can be found to secure the immunologic control of the progression of HER-2/neu preneoplastic lesions.

Animals↗

PubMed2004

Proinflammatory cytokines, immune response and tumour progression.

Tumour cells naturally secrete proinflammatory cytokines and chemokines to interact with the microenvironment and regulate neoangiogenesis. The repertoire of factors thus produced shapes tumour progression. However, experiments in the mouse have shown that injection of a low pharmacological dose of a proinflammatory cytokine or chemokine into the microenvironment increases the inflammatory reaction so enormously that locally activated leukocytes inhibit or eradicate the tumour. Massive shrinkage of recurrent head and neck squamous cell carcinomas (SCC) and prevention of recurrences after surgical removal of a primary SCC follow perilymphatic administration of low doses of interleukin (IL)2, while low daily doses of IL12 markedly delay carcinogenesis in transgenic mice predestined to die of mammary carcinomas and keep them tumour-free for long periods. The reaction elicited by proinflammatory cytokines evidently has a great potential in tumour control.

Animals↗

PubMed2003

Immunization in tumor prevention.

Recent experimental data suggest that immunity can be activated to prevent tumors. The rationale for prevention is strong because the setting is one endowed with an immune system that is neither impaired by tumor and treatment-induced suppression, nor tolerant to tumor-associated antigens. Oncogenic growth factor receptors are tumor antigens and rational targets for specific immunoprevention. Successful prevention of mammary carcinomas in Her-2/neu transgenic mice is cited as an evidence of the validity of this approach. The specific properties of the Her-2/neu gene product as an antigen and the nature of the immune responses induced by effective preventive treatments are summarized.

Animals↗

PubMed2003

Nonredundant roles of antibody, cytokines, and perforin in the eradication of established Her-2/neu carcinomas.

Since the mechanisms by which specific immunity destroys Her-2/neu carcinoma cells are highly undetermined, these were assessed in BALB/c mice vaccinated with plasmids encoding extracellular and transmembrane domains of the protein product (p185(neu)) of the rat Her-2/neu oncogene shot into the skin by gene gun. Vaccinated mice rejected a lethal challenge of TUBO carcinoma cells expressing p185(neu). Depletion of CD4 T cells during immunization abolished the protection, while depletion of CD8 cells during the effector phase halved it, and depletion of polymorphonuclear granulocytes abolished all protection. By contrast, Ig mu-chain gene KO mice, as well as Fcgamma receptor I/III, beta-2 microglobulin, CD1, monocyte chemoattractant protein 1 (MCP1), IFN-gamma, and perforin gene KO mice were protected. Only mice with both IFN-gamma and perforin gene KOs were not protected. Although immunization also cured all BALB/c mice bearing established TUBO carcinomas, it did not cure any of the perforin KO or perforin and IFN-gamma KO mice. Few mice were cured that had knockouts of the gene for Ig mu-chain, Fcgamma receptor I/III, IFN-gamma, or beta-2 microglobulin. Moreover, vaccination cured half of the CD1 and the majority of the MCP1 KO mice. The eradication of established p185(neu) carcinomas involves distinct mechanisms, each endowed with a different curative potential.

Animals↗