<<Disclaimer: Verify this information before applying it to your situation.>>

Thanks to all of you  who answered my question, Especially Cindy in NJ
who sent me to Scott Adams Celiac Website where I got the following:

"Cellulose is a carbohydrate polymer of D-glucose.  It is the structural
material of plants, such as wood in trees.  It contains no gluten
protien."

Due to a conversation with another celiac friend, I would also like to
add Scott's comments on Maltodextrin to this post:

"Maltodextrin is prepared as a white powder or concentrated solution by
partial hydrolysis of corn starch or potato starch with safe and
suitable  acids and enzymes.  (1) Maltodextrin when listed on food sold
in the USA must be  (per FDA regulation) made from corn or potato.  This
rule does not apply to vitamin or mineral supplements and medications."