Fig. 2

Exposure of FDC lines to HIV-1 strains. Expression of potential HIV-1 receptors on FDC lines (a). The bars represent the mean expression value and standard deviation for CD21, Siglec 1, CCR5, CXCR4, CD4, DC-SIGN, β7 and α4 integrins, TAM Axl, TAM Mer and Dtk Mer in 3 FDC lines. Data was normalized to the percentage of positive cells detected with the isotype control antibodies. Nested PCR for detection of HIV-1 RNA and proviral DNA (b). The expected PCR product size of 138 bp detected through pol primers JA79-JA82 and JA80-JA81 confirmed the infection of FDC 1401 and 1402 cells with the HIV-1 strains IIIB and SF162. The upper band visible in the picture represents the amplicon for the outer primers. RNA and DNA were prepared from FDCs cells at day 7 post-exposure. HIV-1 p24 antigen in culture supernatants from FDC lines 1401, 1402 and 1403 at 10 days post-exposure with IIIB and SF 162, as measured by ELISA (c). The cut off OD value is 0.28 and results above this limit where considered positive