DNAJA3 regulates B cell development and immune function.

BACKGROUND: DnaJ homolog subfamily A member 3 (DNAJA3), also known as the tumorous imaginal disc (Tid1), is shown to be crucial in T cell development. DNAJA3 functions as a tumor suppressor implicated in lymphocyte development and survival. However, the role of DNAJA3 in B cell development and immune function remains unknown. In this study, we utilized a mouse model of B cell-specific DNAJA3 knockout (CD19-Cre/+; DNAJA3flx/flx) to investigate the physiological function of DNAJA3 in B cell development and immune function. METHODS: We characterized B cell populations in various developmental stages and examined mitochondrial content and function between control and DNAJA3 KO using flow cytometry analysis. DNAJA3 and OXPHOS protein complexes in sorted B cells between mice groups were compared using immunoblot techniques. The activity of B cell blastogenesis in splenocytes was measured by performing CFSE and MTT assays. Furthermore, immunoglobulin production was detected using the ELISA method. RESULTS: DNAJA3 deficiency decreases from pro B cells to immature B cells. The overall B220+ population in the bone marrow and secondary immune organs also decreased. B cell subpopulations B1 (B1b) and B2 significantly decrease. The B cell blastogenesis activity and immunoglobulin production decreased in DNAJA3 KO mice. Mechanistically, DNAJA3 deficiency significantly increases dysfunctional mitochondria activity and decreases mitochondrial mass, membrane potential, and mitochondria respiratory complex proteins. These factors could have influenced B cell differentiation during development, differentiation to antibody-secreting cells, and immune activation. CONCLUSION: Overall, our study provides supportive evidence for the role of DNAJA3 in B cell development and function.

Microstructure and molecular vibration of mannosylerythritol lipids from Pseudozyma yeast strains.

This work highlights microstructure and molecular vibration of mannosylerythritol lipids (MELs) from Pseudozyma aphidis B1 and Pseudozyma hubeiensis TS18 strains collected from brown algae and mangrove sediments. The scanning electron microscopy (SEM) shows the elongated structures with polar budding in the cells of B1 and TS18 yeast strains. The high-resolution transmission electron microscopy (HRTEM) identifies large lipid bodies that contain MELs confirmed by the anthrone test and thin layer chromatography. The HRTEM also reveals unknown electron dense inclusions. The surface-enhanced Raman scattering (SERS) was used to analysis molecular vibrations of cells, MEL mixtures, and purified MELs (A, B, and C) extracted from the B1 and TS18 cells. The peak analysis of Raman spectra suggests a higher level of saturation per fatty acid chain in MEL-B in both B1 and TS18 cells. This work demonstrates that the out-of-plane bending vibrations of the CH bonds in the range of 840-940 cm-1 can serve an efficient indicator for detecting MEL-A, -B, and -C.

Natural vertical transmission of dengue viruses in Aedes aegypti in selected sites in Cebu City, Philippines.

We attempted to determine the vertical transmission of dengue virus (DENV) in Aedes aegypti in selected sites in Cebu City, Philippines. Mosquito sub-adults were collected monthly from households and the field during the wet-dry-wet season from November, 2011 to July, 2012 and were laboratory-reared to adults. Viral RNA extracts in mosquitoes were assayed by hemi-nested RT-PCR. Results showed that 62 (36.26%; n=679) out of 171 mosquito pools (n=2,871) were DENV+. The minimum infection rate (MIR) of DENV ranged from 0 in wet months to 48.22/1,000 mosquitoes in April, 2012 (mid-dry). DENVs were detected in larvae, pupae, and male and female adults, with DENV-4, DENV-3, and DENV-1, in that rank of prevalence. DENV-1 co-infected with either DENV-3 or -4 or with both in April, 2012; DENV-3 and -4 were present in both seasons. More DENV+ mosquitoes were collected from households than in field premises (p<0.001) and in the dry than in the wet season (p<0.05), with significant interaction (p<0.05) between sites and premises but no interaction between sites and seasons (p>0.05). By Generalized Linear Mixed models, the type of premises nested in sites and monthly total rainfall were significant predictors of monthly dengue cases (p<0.05) and not MIR, season, temperature, and relative humidity. Surveillance of DENV prevalence in Ae. aegypti and detecting their natural foci in the dry season provide an early warning signal of dengue outbreak.