Immunocompromised tumor-bearing mice show a selective loss of STAT5a/b expression in T and B lymphocytes.

Abstract

Impaired immune responses are frequently observed in tumor-bearing hosts during progression of tumor growth, but the molecular basis of these functional defects remains unclear. To investigate tumor-induced immunosuppression, we first established that lymphocytes from mice bearing s.c. mammary adenocarcinoma (TS/A) tumors were severely impaired in their ability to generate cellular and humoral Ag-specific responses. Lymphocytes from these mice were then screened for abnormalities in the expression of signal transducing proteins known to be involved in the regulation of cellular immunity. Interestingly, purified T and B cells isolated from immunocompromised tumor-bearing mice displayed a marked decrease in the transcription activators STAT5a and -b at the protein level and to a lesser extent at the mRNA level. By contrast, no change in the expression of STAT1, -3, and -6 or of the TCR itself were detected. The correlation in the loss of T and B cell function with the selective decrease in STAT5a/b expression suggests that regulation of the STAT5 signaling pathway may provide a molecular mechanism for modulating the immune system.

• Authors: F Pericle, R A Kirken, V Bronte, G Sconocchia, L DaSilva, D M Segal
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 159 Issue 6 Pg. 2580-5 (Sep 15 1997) ISSN: 0022-1767 [Print] United States
• PMID: 9300676 (Publication Type: Journal Article)

Chemical References

• DNA-Binding Proteins
• Milk Proteins
• STAT5 Transcription Factor
• Stat5a protein, mouse
• Trans-Activators

Topics

• Animals
• B-Lymphocytes (immunology, metabolism)
• DNA-Binding Proteins (biosynthesis, immunology)
• Immunocompromised Host
• Mice
• Mice, Inbred BALB C
• Milk Proteins
• Neoplasm Transplantation
• Neoplasms, Experimental (immunology)
• STAT5 Transcription Factor
• T-Lymphocytes (immunology, metabolism)
• Trans-Activators (biosynthesis, immunology)