CROI 2018 Abstract eBook

Abstract eBook

Poster Abstracts

studies and inform about targeted screening: Most of the studied diseases were not randomly distributed on the HIV-1 transmission network, which is only partly due to the clustering of demographic properties and other well-known risk factors of comorbidities. Such analysis could hence be helpful in identifying additional pathogenesis traits for specific illnesses, such as HIV-associated encephalopathy as found in the current analysis or other comorbidities.

Ongoing growth competition experiments, and further analysis of specific polymorphisms, are needed to corroborate the potential increase in replicative fitness of subtype F viruses compared to subtype B HIV-1 strains. 171 DETECTION OF ANTI-ASP ANTIBODIES IN SERA OF HIV+ INDIVIDUALS Antonio Mancarella 1 , Elisa De Crignis 2 , Giampietro Corradin 3 , Craig Fenwick 1 , Matthieu Perreau 1 , Giuseppe Pantaleo 1 , Cecilia Graziosi 1 1 Lausanne University Hospital, Lausanne, Switzerland, 2 Erasmus University Medical Center, Rotterdam, Netherlands, 3 University of Lausanne, Lausanne, Switzerland Background: HIV-1 Antisense protein (ASP) is an antisense open reading frame encoding for a highly hydrophobic protein of 20 kDa encompassing Env at the junction of gp120-gp41. Although initially suggested in 1988, existence of ASP remains controversial and its function has yet to be defined. A previous study shows that sera from HIV+ individuals can recognize ASP, suggesting actual production of this protein during infection. In these experiments however, the same sera were used for both immunoprecipitations and immunoblots. This, together with the fact that defective ribosome products with immune response have been reported for HIV-1, may have allowed for cross-reactivity leading to false positives. In this study we report the detection of anti-ASP antibodies in sera of HIV patients by ELISA assay using a panel of overlapping synthetic peptides spanning the whole length of the protein. Methods: ASP-specific antibodies in sera of 14 HIV+ individuals and 9 healthy donors were determined by ELISA using 7 overlapping peptides spanning the whole ASP. 96-well flat-bottom plates were coated overnight with the synthetic peptides (1 peptide/well). Sera were diluted 1:200 prior to screening. Goat anti-human AP-conjugated secondary antibodies were diluted 1:2000. ELISA cut-off was calculated by adding 3 SDs to the mean OD from antigen-negative wells (healthy donors). Results: Of the 14 patients analyzed, 5 (35.7%) had a positive ELISA result against each of the seven peptides tested (p<0.05) (Figure 1). Interestingly, the peptides characterized by the lowest OD values were P58, corresponding in the sense orientation to gp41, and P28 and P43, who corresponding to Env hypervariable regions V4 and V5. Two healthy donors were found to have OD values slightly above the cut-off, probably due to the low number of samples tested. Conclusion: Our data show that anti-ASP antibodies are present in sera from HIV+ individuals. The use of overlapping fragments covering the entire length of the protein indicates that the antibody response is triggered by the whole protein and not by incomplete ribosome products. In addition, peptides derived from different regions of the protein appear to be more or less immunogenic depending on the Env region present in the opposite orientation. Unfortunately no clinical information is available for the patients tested. We are currently planning a large scale testing of sera from HIV-infected individuals before and after seroconversion and/or undergoing different therapeutic regimens.

Poster Abstracts

170 IS FITNESS RESPONSIBLE FOR POORER ART RESPONSE IN HIV-1 SUBTYPE F INFECTED PATIENTS? Eva Poveda 1 , Dane Winner 2 , Samira Joussef 3 , Berta Pernas 1 , Marta Grandal 1 , Antonio Aguilera 4 , Angeles Castro 1 , Alvaro Mena 1 , Miguel E. Quinones-Nateu 3 1 Instituto de Investigación Biomédica de A Coruña, A Coruña, Spain, 2 University Hospitals Cleveland Medical Center, Cleveland, OH, USA, 3 Case Western Reserve University, Cleveland, OH, USA, 4 Complejo Hospitalario Universitario de Santiago, Santiago de Compostela, Spain Background: Subtype F HIV-1 is highly prevalent in Northwestern (NW) Spain, having reached 36% of newly diagnosed HIV-infected individuals by the end of 2016. We have shown an impaired response to antiretroviral treatment (ART) in patients infected with HIV-1 subtype F viruses compared to those infected with subtype B. Here, we characterized a series of subtype F and B viruses from NW Spain patients to better understand the mechanism(s) associated with these findings. Methods: Plasma samples from patients infected either with subtype F (n=10) or B (n=10) viruses, and clinical/virological data, were obtained from two hospitals in NW Spain. Two sets of recombinant viruses (3’Gag/PR/RT/INT and env) were constructed and used in drug susceptibility and neutralization assays, respectively, and also in viral growth kinetics (VGK) experiments. A deep sequencing-based HIV-1 genotyping assay was used to determine drug resistance and coreceptor tropism. Finally, we used deep sequencing to analyze near full-length HIV-1 genomes and determine intra-patient HIV-1 quasispecies diversity. Results: No major differences in demographics/clinical characteristics were observed between both groups (F vs. B) with the exception of baseline plasma viral load (5.65 vs. 4.91 log c/ml, p = 0.013) and time to reach undetectable viremia (<50 log c/ml; 49 vs. 20 weeks, p=0.026). HIV-1 phenotypic/genotypic analysis showed that all 20 HIV-1 strains were susceptible to all antiretroviral drugs tested. All viruses were equally neutralized by the bNABs VRC01 and 10E8. Similar VGKs were observed in the 3’Gag/PR/RT/INT-recombinant viruses; however, although no significant, subtype F env-recombinant viruses showed slightly higher replication rates compared to subtype B viruses (median 0.036 vs. 0.015, p=0.119). Intrapatient HIV-1 quasispecies diversity was also slightly higher in subtype F vs. B viruses (1.08 vs. 0.89, p=0.37). Full HIV-1 genome analysis identified 39 polymorphisms present in subtype F but absent in all subtype B viruses, i.e., LTR (2), Gag (5), PR (5), RT (14), INT (3), Vif (3), gp120 (6), and gp41 (1). Conclusion: The significant delay in initial response to ART in patients infected with subtype F viruses may be associated with higher viral replication capacity.

172 STO-609 INHIBITS P24 RELEASE FROM GAG-EXPRESSING CELLS Antonio Valentin, Sue Crawford Baylor College of Medicine, Houston, TX, USA

Background: I recently discovered that a specific inhibitor of CaMKK2, STO-609 (7-Oxo-7H-benzimidazo[2,1-a]benz[de]isoquinoline-3-carboxylic acid acetate),

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CROI 2018