2012;2:a007039. adjacent protomers in Env. View of Lentinan Gln315 based on the crystal structure of a cleaved gp140 trimer derived from the HIV strain BG505 (PDB no. 4NCO (Julien et al., 2013)). Two gp120 protomers (Prot1, green (values are based on statistical comparison (Fishers exact test) of the fitted IC50 values from each two neutralization curves (wild-type vs mutant virus). ns, not significant (values 0.05 were considered statistically significant. ? HIGHLIGHTS Anti-V3 antibody B4e8 requires Arg at position 315 in V3 for high affinity binding Subtype C strains were made sensitive to B4e8 upon changing Gln315 in Lentinan V3 for Arg The V2 region in subtype C also hampered anti-V3 antibody access B4e8 variants with higher affinity for Gln-containing V3 sequences may prove useful Supplementary Material 01Figure S1. Mutating Arg315 to Gln in subtype B virus SS1196 reduces B4e8 but not HGN194 binding affinity for solubilized gp120. (A) Antibody binding to solubilized gp120 derived from virus SS1196. (B) Antibody binding to solubilized gp120 from mutant virus SS1196_R315Q. Antibody EH21, to an epitope in the C1 region of gp120, was used as a comparator to ensure that similar levels of gp120 were captured onto microtiter plate wells. Error bars represent the standard error Lentinan of the mean. Click here to view.(51K, tif) 02Figure S2. Arg315-to-Gln substitution in subtype B virus JRCSF reduces to neutralizing activity of HGN194. Replacing Arg315 with a Gln significantly reduces sensitivity of virus JRCSF to the neutralizing activity of the Arg315-independent mAb HGN194. Click here to view.(45K, tif) 03Figure S3. Gln315 is not important for interactions of the V3 tip with adjacent protomers in Env. View of Gln315 based on the crystal structure of a cleaved gp140 trimer derived from the HIV strain BG505 (PDB no. 4NCO (Julien et al., 2013)). Two gp120 protomers (Prot1, green (clones from acute and early subtype B infections for standardized assessments of vaccine-elicited neutralizing antibodies. J Virol. 2005;79:10108C10125. [PMC free article] [PubMed] [Google Scholar]Li M, Salazar-Gonzalez JF, Derdeyn CA, Morris L, Williamson C, Robinson JE, Decker JM, Li Y, Salazar MG, Polonis VR, Mlisana K, Karim SA, Hong K, Greene KM, Bilska M, Zhou J, Allen S, Chomba E, Mulenga J, Vwalika C, Gao F, Zhang M, Korber BT, Hunter E, Hahn BH, Montefiori DC. Genetic and neutralization properties of acute and early subtype C human immunodeficiency virus type 1 molecular clones from heterosexually acquired infections in Southern Africa. J Virol. 2006;80:11776C11790. [PMC free article] [PubMed] [Google Scholar]Liao H-X, Bonsignori M, Alam Lentinan SM, McLellan Jason S., Tomaras Georgia D., Moody MA, Kozink Daniel M., Hwang K-K, Chen X, Tsao C-Y, Liu P, Lu X, Parks Robert J., Montefiori David C., Ferrari G, Pollara J, Rao M, Peachman Kristina K., Santra S, Letvin Norman L., Karasavvas N, Yang Z-Y, Dai K, Pancera M, Gorman J, Wiehe K, Nicely Nathan I., Rerks-Ngarm S, Nitayaphan S, Kaewkungwal J, Pitisuttithum P, Tartaglia J, Sinangil F, Kim Jerome H., Michael Nelson L., Kepler Thomas B., Kwong Peter D., Mascola John R., Nabel Gary J., Pinter A, Zolla-Pazner S, Haynes Barton F. Vaccine Induction of Antibodies against a Structurally Heterogeneous Site of Immune Pressure within HIV-1 Envelope Protein Variable Regions 1 and 2. Immunity. 2013;38:176C186. [PMC free article] [PubMed] [Google Scholar]Liu L, Cimbro R, Lusso P, Berger EA. Intraprotomer masking of third variable loop (V3) epitopes by the first and second variable loops (V1V2) within the native HIV-1 envelope glycoprotein trimer. Proc Natl Acad Sci U S A. 2011;108:20148C20153. [PMC free article] [PubMed] [Google Scholar]Lynch RM, Rong R, Boliar S, Sethi A, Li B, Mulenga J, Allen S, Robinson JE, Gnanakaran S, Derdeyn CA. The B Cell Response Is Redundant and Highly Focused on V1V2 during Early Subtype C Infection in a Zambian Seroconverter. J Virol. 2011;85:905C915. [PMC free article] [PubMed] [Google Scholar]Lynch RM, Rong R, Li B, Nos1 Shen T, Honnen W, Mulenga J, Allen S,.