S226 • OFID 2017:4 (Suppl 1) • Poster Abstracts ASM and IDSA: Editor’s stipends, Editor’s stipends. NBME, Up-to-Date and the Infectious Diseases Board Review Course: NBME, Up-to-Date and the Infectious Diseases Board Review Course, Honoraria. Roche, ASM, and IDSA: Travel reimbursement, Travel reimbursement 613. Pro-Inflammatory and Dysfunctional Immunologic Changes and Risk for Infection in the Older Kidney Transplant Recipient Emily Liang, BA 1 ; Omer Beaird, MD 2 ; Maura Rossetti, PhD 3 ; Tiffany Sidwell, BS 3 ; Victoria Groysberg, BS 4 ; Arun Karlamangla, PhD, MD 5 ; Steve Cole, PhD 6 ; Elaine Reed, PhD 3 and Joanna Schaenman, MD PhD 2 ; 1 David Geffen School of Medicine, Los Angeles, California, 2 Medicine - Infectious Diseases, David Geffen School of Medicine, UCLA, Los Angeles, California, 3 David Geffen School of Medicine, University of California at Los Angeles, Department of Pathology, Los Angeles, California, 4 Pathology/Immunogenetics, David Geffen School of Medicine, University of California at Los Angeles, Department of Pathology, Los Angeles, California, 5 David Geffen School of Medicine, University of California at Los Angeles, Division of Geriatrics, Los Angeles, California, 6 David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California Session: 69. Immunology - Host Response Thursday, October 5, 2017: 12:30 PM Background. Compared with younger patients on similar immunosuppres- sion regimens, older solid organ transplant recipients experience increased rates of infection and death, but decreased rates of rejection; however, rejection episodes are oſten difficult to reverse. e mechanism behind this vulnerability has yet to be defined. Methods. Peripheral blood mononuclear cells were isolated from 23 older ( 3 age 60) and 37 matched younger (ages 30–59) kidney transplant recipients 3 months after transplantation. Immunophenotyping was performed by mul- tiparameter flow cytometry. RNA extraction was performed on banked PBMCs. Isolated RNA was converted to fluorescent cRNA and hybridized to Illumina Human HT-12 v4 BeadArrays. Gene expression values were quantile-normalized and log2-transformed for mixed effect linear model analyses to identify differ- ential expression as a function of age, adjusted for induction type, donor type, and sex. Statistical analysis was performed using Jmp Pro 11 or R soſtware. Results. Older kidney transplant recipients had a statistically significant increase in frequency of classical, pro-inflammatory monocytes (29.5% vs. 14.7%, P = 0.019) and a decrease in frequency of non-classical anti-inflammatory mono- cytes (69.1% vs. 81.3%, P = 0.019). The frequency of senescent CD8+CD57+CD28- T cells was increased in older patients (P = 0.036), as well as in those with episodes of infection or CMV reactivation (P = 0.035). Genes differentially expressed in older patients revealed an over-representation of inflammatory genes and an underrepresentation of genes associated with the antiviral immune response. Tables: Top 10 genes upregulated or downregulated in older compared with younger patients. Conclusion. Older kidney transplant recipients displayed increased fre- quency of senescent T cells, which was associated with increased rates of infec- tion. In addition, we observed pro-inflammatory changes marked by increase in pro-inflammatory monocyte subtypes. Increased levels of inflammation were also reflected by changes in gene expression. These findings may explain the increase in adverse clinical outcomes in older patients, and suggest future avenues for patient risk stratification and individualization of immune suppression after solid organ transplantation. Disclosures. All authors: No reported disclosures. 614. Human Antibodies Induced by an Immunotherapeutic Vaccine (NDV-3A) Containing Als3p, Abrogate Virulence Traits of Candida albicans Priya Uppuluri, PhD 1 ; Abdullah Alqarihi, MS 1 ; John Hennessey, PhD 2 ; John Edwards, Jr., MD 1 and Ashraf S. Ibrahim, PhD 1 ; 1 Los Angeles Biomedical Research Institute at Harbor UCLA Medical Center, Torrance, California, 2 NovaDigmTM erapeutics, Brookline, MA Session: 69. Immunology - Host Response Thursday, October 5, 2017: 12:30 PM Background. NDV-3A is a vaccine containing a recombinant version of the Candida albicans Als3 protein (Als3p) formulated with aluminum hydroxide (AlOH). A recently completed exploratory Phase 2a clinical trial of NDV-3A, referred to as NDV3A-003, showed that women with recurrent vulvovaginal candidiasis (RVVC) could be protected from recurrence of VVC for up to 12 months post-vaccination. Vaccination with NDV-3A induces a robust anamnestic immune response character- ized by high anti-Als3 antibody titers when compared with placebo AlOH-vaccinated subjects. We evaluated whether these anti-Als3p antibodies could have an influence on the virulence traits of C. Albicans. Methods. Sera from patients vaccinated with NDV-3A or placebo were tested. e vaccinated subjects were further divided into those without recurrence of VVC post-vaccination (non-recurrent) vs. those who had a recurrence within the obser- vation period (recurrent patients). In total, 98 serum samples collected from various patients were mixed with growth media at a 19:1 ratio (media:serum), and compared for their ability to impact C. Albicans, 1) adherence to plastic by XTT assay, 2) invasion of vaginal epithelial cells using fluorescent differential counting, and 3) biofilm forma- tion on plastic and catheter material. e ability of antibodies to trigger opsonophago- cytosis of C. Albicans by human neutrophils was also studied. Results. Sera from non-recurrent patients (n = 26) abrogated hyphal elongation, adhesion to plastic, invasion of vaginal epithelial cells, and biofilm formation, signifi- cantly more than sera from recurrent patients (n = 33; P < 0.01) or placebo recipients (n = 39). Biofilm growth was prevented even aſter 72 hours of initial treatment. e inhibitory effect of sera was due to antibodies, since depletion of antibodies by C. Albicans adsorp- tion resulted in loss of the inhibitory activity, while heat inactivation of sera did not. Finally, antibodies enhanced opsonophagocytosis of the fungus by human neutrophils. Conclusion. Anti-Als3p antibodies likely have a pivotal role in protecting against RVVC. A passive antibody therapy, or attaching of Als3 antibodies to abiotic surfaces, could prove a useful strategy against C. Albicans device-associated infections. Disclosures. All authors: No reported disclosures.  615. Seroepidemiology of Opsonophagocytic Antibodies to Serotype Ia, Ib, II, III, and V Group B Streptococcus among Infant, Young Adult, and Elderly Koreans Ji Hyen Lee, MD 1,2 ; Hye Kyung Cho, MD, PhD 3 ; Hyunju Lee, MD, PhD 4 ; Soyoung Lee, MD, PhD 2 ; Han Wool Kim, MD, PhD 2 and Kyung-Hyo Kim, MD, PhD 1,2 ; 1 Department of Pediatrics, Sch. of Med., Ewha Womans University, Seoul, Korea, Republic of (South), 2 Ctr. for Vaccine Evaluation and Study, Ewha Med. Res. Inst., Sch. of Med., Ewha Womans University, Seoul, Korea, Republic of (South), 3 Department of Pediatrics, Gachon University Gill Medical Center, Incheon, Korea, Republic of (South), 4 Seoul National University Bundang Hospital, Seongnam, Korea, Republic of (South) Downloaded from https://academic.oup.com/ofid/article/4/suppl_1/S226/4294082 by guest on 20 December 2023