You can watch the anime Cells at Work on crunchyroll.
Japanese subtitles for the show are available here.
A few useful words from episode 1:
白血球 はっけっきゅう white blood cell, leukocyte
肺炎球菌 はいえんきゅうきん pneumococcus
細菌 さいきん bacterium
赤血球 せっけつだま red blood cell, erythrocyte
血管 けっかん blood vessel
莢膜
きょうまく capsule, theca
反応 はんのう reaction, response
栄養分 えいようぶん nutrition