Red grapes and blueberries have compounds that could improve human immune systems, according to researchers with the Linus Pauling Institute at Oregon State University.

Resveratrol in red grapes and pterostilbene in blueberries — both classed as stilbenoids — were among 446 compounds examined. Both work in tandem with vitamin D.

The findings were made in laboratory cell cultures and don’t prove consumption would have similar results. But they raise interest in the potential of some foods to improve immune response.

The study led by associate professor Adrian Gombart was published in the journal “Molecular Nutrition and Food Research” in September. An abstract is online.

The two compounds increased activity of the human cathelicidin antimicrobial peptide — or CAMP gene — several times over, according to the research. The gene is involved in immune function.

“Out of a study of hundreds of compounds, just these two popped right out,” Gombart said in a news release. “Their synergy with vitamin D to increase CAMP gene expression was significant and intriguing.”

The findings extend Gombart’s previous work linking vitamin D to the gene. Stilbenoids are compounds produced by plants to fight infections. In humans they appear to affect signaling pathways that allow vitamin D to have this effect on the gene, the research found.

Resveratrol, found in red grapes, has been the topic of multiple studies on everything from improving cardiovascular health to fighting cancer and reducing inflammation.

Further research could improve understanding of how diet and nutrition affect immune function, according to the study. Some applications that may evolve for the two compounds could be for topical use with wounds or infections.