<p>Immune System ACROSS 3 foreign substance that antibodies bind to 5 being unable to become sick from a certain pathogen 9 disease-causing agent 10 attacks and kills cells that have been invaded by pathogens 12 a substance that causes an allergic reaction 14 large cell that "eats" invaders 15 medicine that prevents a pathogen from making you ill 16 removes pathogens that haven't entered cells yet 18 when the body attacks its own cells</p><p>DOWN 1 cell that produces antibodies 2 proteins specific to a substance, which they bind to 4 human immunodeficiency virus 5 immune response involving swelling and redness 6 physical barrier against pathogens 7 helps protect that body from pathogens it has had before 8 specialized white blood cell that invokes a specific immune response 11 chemical that stimulates an immune response 13 an immune response to a normally harmless antigen 17 disease resulting when HIV is active in the body </p>