A number of endogenous and exogenous factors, such as cytokines and growth factors as well as certain antifungal agents have been found that they influence innate immune response to these organisms. Used alone or especially in combination have been shown to HSP inhibition exert antifungal effects against Mucorales species. These findings suggest novel ways of adjunctive therapy for patients with invasive mucormycosis. Infections caused by Mucorales have been reported with increasing frequency in recent years and still cause unacceptably high morbidity

and mortality. A number of risk factors are known to be associated with invasive mucormycosis, including haematologic malignancies and transplantation, iron overload, diabetes and ketoacidosis, birth prematurity and possibly prior exposure to certain Aspergillus-active antifungal agents [i.e. voriconazole (VRC) and caspofungin (CAS)].[1-3] In the haematology

patients, the cumulative incidence of mucormycosis in Europe and the United States has been increasing during the last decade, recording high mortality rates and suboptimal outcomes with currently available therapy.[4-7] Among clinically relevant Mucorales, the most frequent species are Rhizopus oryzae and Rhizopus microsporus. Cunninghamella bertholletiae is less MG 132 commonly encountered but associated with more severe infections.[8] By comparison, Lichtheimia corymbifera is a less virulent and infrequent Bcl-w pathogen.[9] Sporangiospores of Mucorales invade into patients through either airways

or mucosa of alimentary tract or through the skin. The alimentary tract is the route of invasion in premature neonates with gastrointestinal mucormycosis. Similarly, Mucorales colonising gauzes, wooden sticks or other materials used into contact with the skin have caused outbreaks of cutaneous or invasive mucormycosis in neonates and other patients.[10] Mucorales can also enter subcutaneous tissues through catheter sites. When sporangiospores enter tissues, they progress to hyphae. The initial host defences against sporangiospores of Mucorales are intact barriers, i.e. skin and respiratory as well as intestinal mucosa. Innate immune cells such as neutrophils, monocytes/macrophages and dendritic cells are important in the host defences against these organisms. Immunosuppression is among the most important risk factors for mucormycosis. Rhizopus oryzae is recognised by Toll-like receptor-2 and up-regulates release of a number of cytokines and chemokines from phagocytes, among which are TNF-α and IL-6.[11, 12] Toll receptors in Drosophila play a significant role in innate immune response to R. oryzae.[11] This organism is more resistant to phagocytosis and hyphal damage than A. fumigatus.[13, 14] There are several lines of in vitro evidence showing that R.