Related Experiment Video

Updated: Jun 20, 2026

Experimental Melanoma Immunotherapy Model Using Tumor Vaccination with a Hematopoietic Cytokine
09:15

Experimental Melanoma Immunotherapy Model Using Tumor Vaccination with a Hematopoietic Cytokine

Published on: February 24, 2023

Tumor vaccines expressing flt3 ligand synergize with ctla-4 blockade to reject preimplanted tumors

Michael A Curran1, James P Allison

  • 1Howard Hughes Medical Institute, Department of Immunology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.

Cancer Research
|September 10, 2009
PubMed

Insights

Combining Flt3 ligand (Flt3L) with CTLA-4 blockade effectively rejects melanoma and prostate cancer in mice. This novel vaccine strategy, Fl3vax, shows promise for broad-spectrum tumor immunity by enhancing T-cell and dendritic cell infiltration.

Area of Science:

  • Immunology
  • Oncology
  • Cancer Research

Background:

  • Cancer development involves genetic mutations and gene expression changes, with limited shared alterations between patients.
  • Harnessing individual tumor-specific immunity is crucial for broad-spectrum cancer treatment.
  • Previous studies showed combining CTLA-4 blockade with GM-CSF-expressing tumor vaccines (Gvax) rejected murine melanomas.

Purpose of the Study:

  • To investigate the efficacy of Flt3 ligand (Flt3L) expressed in B16 melanoma cells, combined with CTLA-4 blockade, for cancer rejection.
  • To compare the effectiveness of Flt3L-expressing vaccines (Fl3vax) with GM-CSF-expressing vaccines (Gvax).
  • To determine if this therapeutic approach extends beyond melanoma to other cancer types, such as prostate adenocarcinoma.

Main Methods:

  • Mice were vaccinated with irradiated B16 melanoma cells engineered to express Flt3L (Fl3vax) or GM-CSF (Gvax).
  • Vaccines were administered in combination with blockade of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4).
  • Tumor rejection, immune cell infiltration (CD8+ T cells, dendritic cells), and therapeutic effects on established B16 melanoma and TRAMP prostate tumors were assessed.

Main Results:

  • Fl3vax, combined with CTLA-4 blockade, induced prophylactic and therapeutic rejection of B16 melanoma in 75% of mice.
  • Fl3vax demonstrated superior efficacy compared to Gvax, preventing tumor outgrowth in more mice.
  • Fl3vax enhanced infiltration of CD8+ T cells and dendritic cells into tumors and vaccine sites.
  • The combination therapy also promoted rejection of established TRAMP prostate adenocarcinomas.
  • Engineered Flt3L vaccine with an IgG2a tail further improved tumor rejection rates.

Conclusions:

  • Flt3L-expressing tumor vaccines combined with CTLA-4 blockade represent a potent strategy for inducing tumor rejection.
  • This approach enhances anti-tumor immunity by increasing T-cell and dendritic cell presence.
  • The therapeutic utility of Flt3L and CTLA-4 blockade extends to various cancer types, including prostate cancer.
  • Optimized Flt3L vaccines offer improved efficacy in preventing tumor outgrowth.

More Related Videos

Tumor Transplantation for Assessing the Dynamics of Tumor-Infiltrating CD8+ T Cells in Mice07:36

Tumor Transplantation for Assessing the Dynamics of Tumor-Infiltrating CD8+ T Cells in Mice

Published on: June 12, 2021

Flow Cytometry-Based Isolation and Therapeutic Evaluation of Tumor-Infiltrating Lymphocytes in a Mouse Model of Pancreatic Cancer07:55

Flow Cytometry-Based Isolation and Therapeutic Evaluation of Tumor-Infiltrating Lymphocytes in a Mouse Model of Pancreatic Cancer

Published on: January 17, 2025

Related Concept Videos

Tumor Immunotherapy01:27

Tumor Immunotherapy

Immunotherapy is a treatment that boosts or manipulates the immune system to fight diseases, including cancer. For instance, by stimulating an immune response through vaccinations against viruses that cause cancers, like hepatitis B virus and human papillomavirus, these diseases can be prevented. Nonetheless, some cancer cells can avoid the immune system due to their rapid mutation and division. The immune response to many cancers involves three phases: elimination, equilibrium, and escape.
Cancer Vaccines01:30

Cancer Vaccines

Cancer treatment vaccines are a rapidly evolving field that offers a promising approach to immunotherapy. Unlike traditional vaccines that prevent diseases, cancer treatment vaccines are designed to treat existing cancers by stimulating the immune system to recognize and attack cancer cells.
Cancer vaccines come in two categories: preventive (prophylactic) and treatment (active). Preventive vaccines, such as the Human Papillomavirus (HPV) vaccine, protect against viruses that cause certain...
Targeted Cancer Therapies02:57

Targeted Cancer Therapies

The targeted cancer therapies, also known as “molecular targeted therapies,” take advantage of the molecular and genetic differences between the cancer cells and the normal cells. It needs a thorough understanding of the cancer cells to develop drugs that can target specific molecular aspects that drive the growth, progression, and spread of cancer cells without affecting the growth and survival of other normal cells in the body.
There are several types of targeted therapies against specific...