Blastocystis has a widespread distribution in a variety of animals, which is a potential source of infection for humans. Previous studies show that Blastocystis sp. subtypes 1-4, 6, and 7 were composed of isolates from humans and animals, while Blastocystis sp. subtype 5 included only pig and cattle isolates. A more recent study on the basis of the SSU rDNA sequence has showed that a single Blastocystis isolate amplified directly from the faeces of a Thai human belongs to Blastocystis sp. subtype 5, but that study failed to cultivate this isolate. We report herein two human isolates from in vitro cultures belonging to Blastocystis sp. subtype 5 and one human isolate from in vitro culture containing two distinct genotypes of Blastocystis sp. subtypes 3 and 5 using PCR amplification with seven kinds of sequence-tagged site (STS) primers. Additionally, 16 Blastocystis isolates from pigs living in the same rural area with the three humans infected Blastocystis sp. subtype 5 were also genotyped by PCR with the STS primers, and all isolates from pigs and humans were compared by small-subunit ribosomal RNA (SSU rRNA) restriction-fragment-length polymorphism (RFLP) analyses using two restriction endonucleases (HinfI and RsaI). The results indicated that all of the isolates from pigs showed Blastocystis sp. subtype 5 and the RFLP patterns of all of the isolates from humans except for the mixed one were identical or quite similar to those of the 16 pig isolates with both HinfI and RsaI enzymes. These findings provide additional molecular-based evidence supporting the zoonotic potential of Blastocystis sp. subtype 5. This study also showed that Blastocystis sp. subtype 3 overgrew Blastocystis sp. subtype 5 in vitro.

Activated macrophages play an important role in many inflammatory diseases including septic shock and atherosclerosis. However, the molecular mechanisms limiting macrophage activation are not completely understood. Members of the tripartite motif (TRIM) family have recently emerged as important players in innate immunity and antivirus. Here, we systematically analyzed mRNA expressions of representative TRIM molecules in human THP1-derived macrophages activated by different toll-like receptor (TLR) ligands. Twenty-nine TRIM members were highly induced (>3 fold) by one or more TLR ligands, among which 19 of them belong to TRIM C-IV subgroup. Besides TRIM21, TRIM22 and TRIM38 were shown to be upregulated by TLR3 and TLR4 ligands as previous reported, we identified a novel group of TRIM genes (TRIM14, 15, 31, 34, 43, 48, 49, 51 and 61) that were significantly up-regulated by TLR3 and TLR4 ligands. In contrast, the expression of TRIM59 was down-regulated by TLR3 and TLR4 ligands in both human and mouse macrophages. The alternations of the TRIM proteins were confirmed by Western blot. Finally, overexpression of TRIM59 significantly suppressed LPS-induced macrophage activation, whereas siRNA-mediated knockdown of TRIM59 enhanced LPS-induced macrophage activation. Taken together, the study provided an insight into the TLR ligands-induced expressions of TRIM family in macrophages.

The β-1,3-D: -glucan binding protein (βGBP), one kind of the pattern recognition proteins (PRPs), was cloned and characterized from the Chinese Shrimp Fenneropenaeus chinensis, and named as FcβGBP-HDL. The results indicated that the full length cDNA of 6713 bp had an open reading frame encoded a polypeptide of 2139 amino acids with two glucanase-like motifs and one RGD motif, while without signal peptide. The calculated molecular mass of mature protein was 240.7 kDa and theoretical pI was 5.95. Sequence comparison of the deduced amino acid sequence of FcβGBP-HDL showed varied identity of 88, 54 and 53% with those of Litopenaeus vannamei βGBP-HDL, Pacifastacus leniusculus βGBP, and Pontastacus leptodactylus βGBP, respectively. qRT-PCR analysis indicated that FcβGBP-HDL was expressed in intestines, hepatopancreas, muscle, gill and hemocytes, and its profile was modified post WSSV challenge. The differential expressions of FcβGBP-HDL in different tissues post WSSV challenge suggested that FcβGBP-HDL might play an important role in shrimp immune and perform differently in different tissues. These data would be helpful to better understand the WSSV-resistance mechanism of farming shrimp.