The present invention relates to a method for suppressing infectivity of HIV which includes contacting the HIV or a cell targeted by HIV with an effective amount of a thrombospondin or a thrombospondin analog. Other aspects of the invention relate to contraceptives, pharmaceutical compositions, and non-contraceptive prophylactic devices that include a carrier and a thrombospondin or a thrombospondin analog. Methods of inhibiting HIV infection in a patient, blocking HIV binding to a cell, blocking chemokine binding to its receptor, and treating or preventing inflammatory states in a patient are also disclosed.