Dendritic cell TLR4 induces Th1-type immune response against Cryptosporidium parvum infection

@#The objective of this study was to investigate the mechanism of Toll-like receptor (TLR4)- mediated dendritic cell (DC) immune against Cryptosporidium parvum infection. C. parvum sporozoites were labeled with 5,6-carboxyfluorescein diacetate succinimidyl ester. Murine bone marrow-derived DCs were isolated, and divided into TLR4 antibody blocking (TAB; infected with 2 × 105 labeled sporozoites and 0.5 μg TLR4 blocking antibody), TLR4 antibody unblocking (TAU; infected with 2 × 105 labeled sporozoites), and blank control (BC; with 1.5 mL Roswell Park Memorial Institute 1640 medium) groups. The adhesion of Cryptosporidium sporozoites to DCs and CD11c+ levels were examined by fluorescence microscopy and flow cytometry. Male KM mice were orally injected with C. parvum. The proliferation of T lymphocytes in spleen, expression of cytokines in peripheral blood, and TLR4 distribution features in different organs were further determined by immunohistochemistry. A significantly higher expression of CD11c+ and higher C. parvum sporozoite adhesion were found in the TAU group compared with other groups. The expression of CD4+CD8- /CD8+CD4- in the spleen were obviously differences between the TAB and TAU groups. The expression of TLR4, interleukin IL-4, IL-12, IL-18 and IFN-γ improved in the TAU group compared with TAB group. Higher expression of TLR4 was detected in the lymph nodes of mice in the TAU group, with pathological changes in the small intestine. Hence, TLR4 could mediate DCs to recognize C. parvum, inducing Th1 immune reaction to control C. parvum infection.

Cloning of a novel gene, Cymg1, related to family 2 cystatins and expressed at specific stages of mouse testis development.

We have cloned a novel gene, Cymg1 (GenBank accession number AY600990), from a mouse testis cDNA library. Cymg1 is located in 2G3 of mouse chromosome 2. The cDNA includes an open reading frame that encodes 141 amino acid residues. The encoded polypeptide has a cysteine protease inhibitor domain found in the family 2 cystatins but lacks critical consensus sites important for cysteine protease inhibition. These characteristics are seen in the proteins of the CRES subfamily of the family 2 cystatins which are expressed specifically in the reproductive tract. CYMG1 protein shows 44% identity with mouse CRES and 30% identity with mouse cystatin C. Northern blot analysis showed that the Cymg1 gene was specifically expressed in adult mouse testis. RT-PCR also showed that Cymg1 was expressed in testis and spermatogonial cells. Cymg1 expression level varied in the different developmental stages of mouse testis, and were coincidental with spermatogenesis and sex maturation. These results indicate that Cymg1 may play important roles in mouse spermatogenesis and sex maturation.