Effective chemoimmunotherapy with anti-TGFβ antibody and cyclophosphamide in a mouse model of breast cancer

PLoS One. 2014 Jan 9;9(1):e85398. doi: 10.1371/journal.pone.0085398. eCollection 2014.

Abstract

TGFβ is reportedly responsible for accumulation of CD4(+)Foxp3(+) regulatory T cells (Tregs) in tumor. Thus, we treated mouse 4T1 mammary carcinoma with 1D11, a neutralizing anti-TGFβ (1,2,3) antibody. The treatment delayed tumor growth, but unexpectedly increased the proportion of Tregs in tumor. In vitro, 1D11 enhanced while TGFβ potently inhibited the proliferation of Tregs. To enhance the anti-tumor effects, 1D11 was administered with cyclophosphamide which was reported to eliminate intratumoral Tregs. This combination resulted in long term tumor-free survival of up to 80% of mice, and the tumor-free mice were more resistant to re-challenge with tumor. To examine the phenotype of tumor infiltrating immune cells, 4T1-tumor bearing mice were treated with 1D11 and a lower dose of cyclophosphamide. This treatment markedly inhibited tumor growth, and was accompanied by massive infiltration of IFNγ-producing T cells. Furthermore, this combination markedly decreased the number of splenic CD11b(+)Gr1(+) cells, and increased their expression levels of MHC II and CD80. In a spontaneous 4T1 lung metastasis model with resection of primary tumor, this combination therapy markedly increased the survival of mice, indicating it was effective in reducing lethal metastasis burden. Taken together, our data show that anti-TGFβ antibody and cyclophosphamide represents an effective chemoimmunotherapeutic combination.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antibodies, Neutralizing / pharmacology*
  • Antineoplastic Agents, Alkylating / pharmacology*
  • B7-1 Antigen / genetics
  • B7-1 Antigen / immunology
  • CD11b Antigen / genetics
  • CD11b Antigen / immunology
  • Carcinoma / immunology
  • Carcinoma / mortality
  • Carcinoma / pathology
  • Carcinoma / therapy*
  • Cell Line, Tumor
  • Cyclophosphamide / pharmacology*
  • Drug Synergism
  • Drug Therapy, Combination
  • Female
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / immunology
  • Gene Expression / immunology
  • Humans
  • Immunotherapy*
  • Interferon-gamma / genetics
  • Interferon-gamma / immunology
  • Lymphocyte Count
  • Mammary Glands, Animal / drug effects
  • Mammary Glands, Animal / immunology
  • Mammary Glands, Animal / pathology
  • Mammary Neoplasms, Experimental / immunology
  • Mammary Neoplasms, Experimental / mortality
  • Mammary Neoplasms, Experimental / pathology
  • Mammary Neoplasms, Experimental / therapy*
  • Mice
  • Survival Analysis
  • T-Lymphocytes, Regulatory / drug effects
  • T-Lymphocytes, Regulatory / immunology
  • T-Lymphocytes, Regulatory / pathology
  • Transforming Growth Factor beta / antagonists & inhibitors*
  • Transforming Growth Factor beta / immunology

Substances

  • Antibodies, Neutralizing
  • Antineoplastic Agents, Alkylating
  • B7-1 Antigen
  • CD11b Antigen
  • Forkhead Transcription Factors
  • Foxp3 protein, mouse
  • Transforming Growth Factor beta
  • Interferon-gamma
  • Cyclophosphamide