Immune Response To Peptide Vaccine Best Measured In Lymph Nodes.(Brief Article)

2001 JUN 27 - (NewsRx.com & NewsRx.net) --

by N.R. Saltmarsh, staff medical writer - Although some melanoma patients have benefited from peptide vaccines, their clinical responses have not consistently corresponded to measurements of immune responses in peripheral blood lymphocytes (PBLs).

Now researchers at the University of Virginia have found a more reliable indicator of whether a melanoma vaccine will work in a specific patient.

Measurements of cytotoxic T lymphocytes (CTLs) from lymph nodes that drained vaccine sites (sentinel immunized nodes, SIN) appear to be more sensitive than CTL measurements in PBLs, reported G.V. Yamshchikov and associates.

They vaccinated five stage IV melanoma patients with gp 100 and tyrosinase peptides restricted by HLA-A1, HLA-A2, and HLA-A3. Granulocyte macrophage colony stimulating factor (GM-CSF) and Montanide ISA-51 were used as adjuvants.

All five patients had CTL responses to the vaccinating peptides in their SIN, but only two of five showed peptide-reactive CTLs in their PBLs, noted Yamshchikov and coworkers ("Evaluation of peptide vaccine immunogenicity in draining lymph nodes and peripheral blood of melanoma patients," International Journal of Cancer, June 1, 2001;92(5):703-711.)

Patients showed immunogenicity for peptides restricted by HLA-A1 and -A3 and for one HLA-A2 restricted peptide, YMDGTMSQV, they added.