Neutrophil extracellular traps formation: effect of Leishmania major promastigotes and salivary gland homogenates of Phlebotomus papatasi in human neutrophil culture.

BACKGROUND: Leishmaniasis as a neglected tropical disease (NTD) is caused by the inoculation of Leishmania parasites via the bite of phlebotomine sand flies. After an infected bite, a series of innate and adaptive immune responses occurs, among which neutrophils can be mentioned as the initiators. Among the multiple functions of these fighting cells, neutrophil extracellular traps (NETs) were studied in the presence of Leishmania major promastigotes and salivary gland homogenates (SGH) of Phlebotomus papatasi alone, and in combination to mimic natural conditions of transmission. MATERIAL & METHODS: The effect of L. major and SGH on NETs formation was studied in three different groups: neutrophils + SGH (NS), neutrophils + L. major (NL), neutrophils + L. major + SGH (NLS) along with negative and positive controls in 2, 4 and 6 h post-incubation. Different microscopic methods were used to visualize NETs comprising: fluorescence microscopy by Acridine Orange/ Ethidium Bromide staining, optical microscopy by Giemsa staining and scanning electron microscopy. In addition, the expression level of three different genes NE, MPO and MMP9 was evaluated by Real-Time PCR. RESULTS: All three microscopical methods revealed similar results, as in NS group, chromatin extrusion as a sign of NETosis, was not very evident in each three time points; but, in NL and especially NLS group, more NETosis was observed and the interaction between neutrophils and promastigotes in NL and also with saliva in NLS group, gradually increased over times. Real-time reveals that, the expression of MPO, NE and MMP9 genes increased during 2 and 4 h after exposure, and then decreased at 6 h in most groups. CONCLUSION: Hence, it was determined that the simultaneous presence of parasite and saliva in NLS group has a greater impact on the formation of NETs compared to NL and NS groups.

Sergentomyia species identification and their screening for possible infection to Leishmania spp. in Kaleybar, East-Azerbaijan province, Iran.

Leishmaniasis is a protozoal and vector-borne disease. World health organization has considered the disease as a neglected tropical disease. Phlebotomus and Lutzumyia species (order: Diptera, family: Psychodidae) are human leishmaniasis vectors in new and old worlds. Sergentomyia spp. (Diptera, Psychodidae) are proven vectors of lizard leishmaniasis. Although some studies have identified human Leishmania parasites in Sergentomyia, their role in parasite circulation is unknown yet. Hence, the parasitological and molecular methods were used to study the possible Leishmania infection of Sergentomyia spp., in the human and canine visceral leishmaniasis endemic area in North West of Iran. Even though Sergentomyia specimens were caught in a dominant number compared to Phlebotomus spp., no Leishmania promastigote or DNA was detected in live-caught or sticky trap-caught specimens, respectively. Sergentomyia spp. are proven vectors of sauroleishmaniasis, and despite several global reports of Leishmania infection in Sergentomyia spp., such findings should be carefully interpreted to avoid false vector incriminations.

Determination of lymphocyte subsets reference values in healthy Iranian men by a single platform flow cytometric method.

Lymphocyte subsets enumeration is of paramount importance in the management of immunodeficiency disorders such as HIV/AIDS. For better interpretation of laboratory findings, reference intervals must be determined in each population. Because of scarcity of published studies from Iranian population, lymphocyte subsets were enumerated in 142 healthy Iranian men by a single platform flow cytometric method. Mean and 95% confidence interval for CD4+ T cells, CD8+ T cells, CD4/CD8 ratio, B cells, and natural killer cells were 748.8 (351-1207), 409.0 (192-752), 1.96 (0.77-3.70), 238.6 (82-500), and 200.7 (91-393), respectively. We compared our results with other studies and found significant differences with some of them. In conclusion, we endorse determination of lymphocyte subsets reference interval in different populations.