Construction of a stable 4.1R gene knockout cell model in RAW264.7 cells using CRISPR/Cas9 technique / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct a cell model of 4.1R gene knockout in murine macrophage cell line RAW264.7 using CRISPR/Cas9 technique.</p><p><b>METHODS</b>Three high?grade small?guide RNAs (sgRNAs) that could specifically identify 4.1R gene were synthesized and inserted into lentiCRISPRv2 plasmid. RAW264.7 cells were infected with sgRNA?Cas9 lentivirus from 293T cells transfected with the recombinant sgRNA?lentiCRISPRv2 plasmid, and the positive cells were screened using puromycin and the monoclonal cells were obtained. The expression of 4.1R protein in the monoclonal cells was measured by Western blotting, and the mutation site was confirmed by sequence analysis. Result A 4.1R gene knockout RAW264.7 cell line was obtained, which showed a 19?bp deletion mutation in the 4.1R gene sequence and obviously enhanced proliferation.</p><p><b>CONCLUSION</b>We successfully constructed a 4.1R gene knockout macrophage cell line using CRISPR/Cas9 technique, which may facilitate further investigation of the function of 4.1R in macrophages.</p>

Survey on contact tracing of newly reported HIV infections in 2009 in Dehong prefecture, Yunnan province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore a new method for finding more HIV/AIDS.</p><p><b>METHODS</b>In September 2009, newly reported HIV-infected individuals from May to August, 2009 in Dehong prefecture were asked to participate in a survey which requested demographic characteristics, history of high-risk behaviors and contact information of individuals with whom they had high risky contacts. People with risky contacts with HIV-infected cases (index cases) were also approached to participate in this survey and HIV testing was provided.</p><p><b>RESULTS</b>A total of 342 HIV-infected individuals were newly reported and served as index cases from May to August, 2009. Among them, 47.1% (161/342) were transmitted by regular sexual partners. Through three-round surveys, 218 contacts were traced and among them, 84.9% (185/218) were traced by regular heterosexual partners. HIV positive rate of the tested was 34.7% (60/173) in the first-round tracing and 12.5% (1/8) in the second one. Among the 560 individuals (index cases and their high-risk contacts), the proportions of having regular heterosexual partners, non-regular and non-commercial sexual partners, commercial sexual heterosexual partners and men having sex men were 87.9% (492/560), 18.9% (106/560), 22.3% (125/560) and 0.3% (1/318), respectively, while the proportion of having never used condoms when having sex with the above four types sexual partners were 73.8% (363/492), 72.6% (77/106), 63.2% (79/125) and 0.0% (0/1), respectively.</p><p><b>CONCLUSION</b>As an epidemiological method for HIV/AIDS finding, contact tracing identified a large number of HIV infectors who were traced by newly reported HIV-infected individuals.</p>

Tracing the sources of newly reported HIV infections in Dehong prefecture of Yunnan province / 中华流行病学杂志

Objective To trace and provide HIV-testing among those having contacts with HIV-infected individuals at various levels in Dehong prefecture, Yunnan province and to evaluate the effectiveness and feasibility of such investigation as a supplemental strategy for HIV testing and control. Methods Newly reported HIV infections from August throughout October in Dehong prefecture, in 2008 were asked to provide contact information of persons whom they had high risk contacts with. Persons having had risk contacts with HIV-infected cases were hereof interviewed and their blood tested on the sero-status of HIV. Results A total of 335 HIV cases were newly reported during this three-month period. A total of 309 cases of them and 148 HIV infections identified thereafter from their risk contacts were under informed consent, to participate in this study. A total number of 3395 risk contacts were reported, of whom only 20.7% (704/3395) had 'contact information' and 51.3% (361/704) were successfully located and interviewed, including 117 previously confirmed HIV infections and 244 people with unknown HIV status. The majority of them (203 or 83.2% of 244) were then tested for HIV and 56(27.6% of 203) were tested positive for HIV. The proportion of having detailed contact information and the proportion of being traced or followed among reported risk contacts of HIV infections were 68.8% and 68.2% for spouses of HIV patients, respectively, which were much higher than those among commercial sex partners (1.2% and 16.7%), casual sex partners (37.3% and 22.3% ) and peers who sharing needles (34.1% and 56.4% ). Conclusion Newly reported HIV infections reported a large number of risk contacts and new HIV infections were identified among them. It was extremely difficult to trace commercial sex partners or casual sex partners on their HIV infection status. Nevertheless, tracing the risk contacts of newly reported HIV infections seemed to be helpful in identifying new HIV infections and in understanding the nature of transmission towards controlling the HIV epidemics.