Navigation Links
One cell type may quash tumor vaccines
Date:4/28/2014

(PHILADELPHIA) -- Most cancer vaccines have not lived up to their promise in clinical trials. The reason, many researchers suspect, is that the immune cells that would help the body destroy the tumor even those reactions boosted by cancer vaccines are actively suppressed. Now, researchers at Thomas Jefferson University have found that a single cell type is actively suppressed in several experimental cancer vaccines, paving the way toward methods to break suppression and improve the effectiveness of cancer vaccines. The work was published this week online in the European Journal of Immunology.

"The conventional wisdom is that the body knocks out all of the cells that can mount an immune response to the cancer," says first author Adam Snook, PhD, a Research Instructor at Thomas Jefferson University. "In fact, our work shows that it's only one cell type that is affected. But that cell, the T-helper cell, acts as the lynchpin."

Cancer vaccines are designed to boost the body's natural defenses against cancer. They work by training the immune system to recognize and attack specific tumor peptides, which are a kind of identification tag for tumors. These peptide "tags" help the immune system find and attack cancer cells. There are three types of cells that can "see" and react to these tags: T-helper cells, cytotoxic T cells, and B cells, and researchers thought that all three were trained, or tolerized, to ignore the tags on cancer cells.

Dr. Snook and colleagues tested which cell was involved by inoculating mice with a cancer vaccine they developed for colorectal cancer using a tumor peptide called guanylyl cyclase C (GUCY2C). Normally, GUCY2C-vaccinated mice would not produce much of an immune response, from either T cell type or B cells. However, when the researchers boosted the GUCY2C vaccine by linking it to another peptide called S1 that efficiently activates T-helper cells, they were able to see a vigorous activation of cytotoxic T cells and B cells directed at GUCY2C.

In fact, the GUCY2C vaccine-S1 combo improved the survival time of mice with cancer by months compared to only days with GUCY2C vaccine alone. In fact, many mice were cured of their disease.

When Dr. Snook tested two other cancer peptides, one for breast cancer (Her2) and one for melanoma (Trp2), he saw similar results, suggesting that selective inactivation of T helper cells occurs for peptides found in many cancer types. "The results make a lot of sense," says Dr. Snook. "T-helper cells, as their name suggests, provide help to both cytotoxic T cells and to B cells. The entire peptide-specific immune response can be taken out by tolerizing this one cell type."

In addition, T-helper cells are also essential for creating immunological memory. Boosting T-helper cell activation also protected mice from challenge with cancer months after the initial vaccination, increasing their survival and decreasing tumor number.

The next step is to test whether a T helper peptide-linked GUCY2C vaccine could help fight colorectal cancer in humans. Dr. Snook and colleagues are currently enrolling patients in a clinical trial aimed at reducing the rate of cancer recurrence in patients who had their primary tumors removed.


'/>"/>

Contact: Edyta Zielinska
edyta.zielinska@jefferson.edu
215-955-5291
Thomas Jefferson University
Source:Eurekalert

Related medicine news :

1. Researchers generate immunity against tumor vessel protein
2. 3D printing cancer tumors
3. Surprising new insights into the PTEN tumor suppressor gene
4. Finnish team of researchers finds a mutation in a tumor of the jaw
5. Scientists find key steps linking dietary fats and colon cancer tumor growth
6. Deep, integrated genomic analysis re-classifies lower-grade brain tumors
7. Prognosis of tumors positive for human papilloma virus in head and neck cancers varies according to the site
8. Adult cancer drugs show promise against an aggressive childhood brain tumor
9. New view of tumors evolution
10. Several FDA-approved anti-cancer drugs induce stem cell tumors, perhaps thwarting therapy
11. Going viral to target tumors
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/23/2017)... ... March 23, 2017 , ... Hakim Unique Group ... technology company California Healthcom Group (CHG). , The HUG investment is a ... headquarters in California, CHG is a growing, internationally recognized healthcare management, technology, and ...
(Date:3/23/2017)... ... March 23, 2017 , ... ... solution that enables organizations to easily reprint customer invoices, bills, statements and other ... all of the steps needed to retrieve and print the documents and batch ...
(Date:3/23/2017)... ... March 23, 2017 , ... ... today announced rapid completion of the strategic executive team expansion needed to further ... to the ChenMed executive team,” says Christopher Chen, MD, ChenMed Chief Executive Officer. ...
(Date:3/23/2017)... , ... March 23, 2017 , ... It’s that time ... many students are thinking about summer internships , which can be frustrating when ... The pros at Garden Media Group, a boutique public relations firm outside of Philadelphia, ...
(Date:3/23/2017)... ... March 23, 2017 , ... ... with all Americans facing life-altering and fatal diseases in opposition to the ... decisions that would eviscerate care, services, and hope for the most vulnerable among ...
Breaking Medicine News(10 mins):
(Date:3/23/2017)... March 23, 2017  Interpace Diagnostics Group, Inc. ... fully integrated commercial company that provides clinically useful ... that it has entered into agreements to successfully ... Shareholders ("RedPath") and concurrently terminate its royalty and ... secured debt to RedPath amounting to $9.34 million ...
(Date:3/23/2017)... 23, 2017 A research report by ... expected to reach USD 7.2 billion by the end of ... is a procedure in which a sample is preserved prior ... analytical procedures since the methods are often allowing repeated testing. ... the most shared procedures in the lab. In many life ...
(Date:3/23/2017)... , March 23, 2017 CENTRO DE IMAGEM ... 157, paragraph 4 of Law 6,404/76 and Instruction 358/02 ... informs its shareholders and the market in general that ... subsidiary Centro de Diagnosticos por Imagem Ltda. (" CDI ... interest in RADIOLOGISTAS ASSOCIADOS LTDA. (" Partnership " and ...
Breaking Medicine Technology: