The present invention is directed to methods of suppressing inflammatory responses, inducing tolerance to an antigen, and suppressing cell adhesion, e.g., involved in metastasis, by the administration of lectin derived carbohydrate binding peptides or derivatives thereof, in particular, peptides capable of binding terminally linked .alpha.-sialic acid(2.fwdarw.6).beta.Gal- and/or .alpha.-sialic acid(2.fwdarw.3).beta.Gal-groups on structures or molecules comprising such groups. Pharmaceutical compositions containing such lectin derived carbohydrate binding peptides or derivatives thereof are also disclosed.