CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

434

CD101 Variants Are Associated With Lower Levels of Genital HIV Inhibiting and Tissue Repair Factors Sarah C Vick 1 , Corinne M. Mar 2 , Bhavna Chohan 2 , Katherine K. Thomas 2 , James W. MacDonald 2 , Theo K. Bammler 2 , Kenneth Ngure 3 , Nelly R. Mugo 1 , Jennifer M. Lund 1 , Jairam Lingappa 2 1 Fred Hutchinson Cancer Center, Seattle, WA, USA, 2 University of Washington, Seattle, WA, USA, 3 Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya Background: We previously demonstrated that Africans with variants in the Ig-like domain of CD101 are associated with an increased risk of heterosexually acquired HIV infection. Recognizing that CD101 has known immunoregulatory functions, we had shown that these CD101 Ig-like variants are associated with reduced regulatory T cell function and increased proinflammatory T cell responses in the circulation. We had not previously examined the effects of these variants on the genital mucosa - the portal of entry for sexually acquired HIV. Here, we explore associations between CD101 Ig-like variants and the level of soluble immune factors in genital secretions that may suggest a mechanism for how these variants impact HIV risk. Methods: We enrolled women without HIV in HIV serodifferent heterosexual couples (with a male partner with HIV, N=44) or HIV seroconcordant negative couples (N=296) in Thika, Kenya consenting to collection of blood and genital samples. We used a custom Open Array (Thermo Fisher) to genotype ten candidate CD101 variants including six Ig-like variants (minor allele frequencies 0.007 – 0.11) and a Luminex assay (Eve Technologies) to measure 71 cytokines and chemokines in enrollment softcup and serum samples from 245 women. We used multivariable linear regression (controlling for frequency of condomless sex, for softcup) to compare the log 10 cytokine and chemokine level in genital secretions or serum from women having one or more Ig-like variants (N=60/245=24%) to women with none of the ten candidate CD101 variants (N=59). Results: Between these two groups, median age 29 (18-54) years, women with one or more vs no CD101 Ig-like variants were associated with a significant reduction in levels of LIF (β= -0.41, p=0.001), G-CSF (β= -0.46, p=0.006), as well as IL-1a, PDGF-AB/BB, RANTES, Eotaxin-2, Eotaxin-3, IL-16, IL-33, and TPO (p=0.025– 0.044) in genital softcup samples. In contrast, we found no significant association of CD101 Ig-like variants with any factors in serum. Conclusion: Our exploratory findings suggest that CD101 Ig-like variants have immunoregulatory impact in the genital mucosa. Notably, RANTES, IL-16, and LIF have demonstrated HIV inhibitory activity. The reduction in these factors observed in genital secretions associated with CD101 Ig-like variants could underlie increased HIV infection risk. Additionally, G-CSF, PDGF-AB/BB, IL-33, and LIF facilitate tissue homeostasis and repair, so reduced levels could compromise mucosal tissue barrier and facilitate pathogen entry. Synergistic Effects of HIV, HPV, and Polyomaviruses on Interferon Response in Male Anal Mucosa Matteo Fracella , Sara Passerini, Letizia Santinelli, Leonardo Sorrentino, Luca Maddaloni, Ginevra Bugani, Eugenio Nelson Cavallari, Alessandra Pierangeli, Guido Antonelli, Claudio Maria Mastroianni, Gabriella D'Ettorre, Valeria Background: Viral persistence is a crucial prerequisite for high-risk (HR) HPV-associated tumor growth, such as anal squamous cell carcinoma (SCC). Men living with HIV (MLWH) are more likely to be co-infected with HPV. Moreover, HIV may alter epithelial integrity, thereby favoring not only HPV but also Polyomaviruses (HPyVs) infections in basal cells, where they dysregulate cell division and local immunity. Indeed, HPyVs have garnered interest due to their carcinogenic potential and their possible presence in the anal mucosa, which could promote transmission through sexual intercourse. To explore the innate response of the anal mucosa in relation to HPV and HPyVs infections, we analyzed the expression of type I/III interferon (IFN)-related genes in anal cells from MLWH and non-MLWH. Methods: Sixty-one anal canal brushing samples were collected from men attending a proctology clinic. Detection of HPV and HPyVs [i. Merkel cell PyV (MCPyV), ii. JCPyV, iii. BKPyV] DNA was performed by PCR, and genotyping by sequencing. From purified cellular RNA, transcripts of genes encoding IFN-I (α, β), IFN-III (λ1-3), and TLR9 were measured by quantitative RT-PCR assays and normalized to the housekeeping GUS gene. Results: Thirty-five MLWH (mean age 47.7 years, SD 11.4), on long-term ART, and twenty-six controls (mean age 47.4 years, SD 15.3) were enrolled in this Pietropaolo, Carolina Scagnolari Sapienza University of Rome, Rome, Italy

Results: Genital ILCs represented <5% of mononuclear immune cells. Subset distribution was compartmentalized, with ILC3s predominant in the endometrium (63% of ILCs), and ILC1s in the ectocervix (48%). In the absence of stimulation, ILC1s constitutively produced IFNγ (14%), while ILC3s produced IL-22 (46%), important for barrier maintenance. We identified two ILC3 subsets at steady state, CCR6+CD103+ and CCR6+CD103-, with the highest IL-22 content (63%; p=0.003), and highest degranulation (CD107a, 10.4%; p=0.002), respectively. Genital ILCs expressed HIV coreceptors (CCR5, CXCR4), but CD4 expression was restricted to ILC1s (p<0.0001). In vitro HIV stimulation increased the percentage of CD107a+ ILC1s (p=0.03), concomitant with a decrease in intracellular IFNγ (p=0.02), indicating IFNγ release and degranulation in response to HIV. For ILC3s, in vitro HIV stimulation induced a significant decrease in the percentage of CCR6+IL22+ cells, regardless of CD103 expression (p=0.03), while CD107a+ cells specifically increased in the CCR6+CD103- population (p=0.06), indicating a response to HIV through IL-22 release. Conclusion: Our findings demonstrate that ILCs reside in the FGT, produce antiviral cytokines under steady-state, and ILC1s and CCR6+CD103- ILC3s degranulate in response to HIV stimulation, indicating a major role in the maintenance of an antiviral environment and the ability to mount an antiviral response. Our investigation suggests ILCs could represent a novel mechanism for protection against HIV acquisition in the FGT. The Cervicovaginal Neutrophil Protein CRISP3 Is a Correlate of HIV Protection Christina Farr 1 , Laura Noël-Romas 1 , Michelle Perner 2 , Marina Costa-Fujushima 2 , Sausan Azzam 1 , Marlon De Leon 1 , Stefanie Avril 1 , Vanessa Poliquin 2 , Alicia R. Berard 2 , Lyle McKinnon 2 , Thomas Murooka 2 , Sharon L. Hillier 3 , Zvavahera Chirenje 4 , Jeanne Marrazzo 5 , Adam Burgener 1 1 Case Western Reserve University, Cleveland, OH, USA, 2 University of Manitoba, Winnipeg, Canada, 3 University of Pittsburgh, Pittsburgh, PA, USA, 4 University of California San Francisco, San Francisco, CA, USA, 5 University of Alabama at Birmingham, Birmingham, AL, USA Background: Identifying immune correlates of HIV protection in the female genital tract is important for HIV prevention efforts. We performed discovery proteomics to identify vaginal mucosal immune predictors of HIV acquisition from 1190 women enrolled in two HIV prevention trials. Methods: We employed a case-control study design including women in the VOICE (MTN-003) trial as the discovery cohort (121 cases, 381 controls) and CAPRISA 004 trial as the validation cohort (62 cases, 626 controls). Mucosal swab and lavage samples from the last seronegative timepoint of HIV cases, and at a comparable time point in controls who remained uninfected during the trials, were analyzed by tandem mass spectrometry, identifying 1051 human proteins. HIV risk associations were determined using logistic regression and machine learning approaches. Biomarker-immune cell associations were studied using cervical samples collected from healthy donors. Results: LASSO regression identified CRISP3 as the strongest correlate of HIV protection in both cohorts (P<0.0001), where above median levels associated with a 3.5-fold reduced risk of HIV acquisition (VOICE: OR=0.28, 95% CI=0.18 0.45, P=3.44E-9; CAPRISA004: OR=0.31, 95% CI=0.16-0.57, P=5.55E-5), and 5-fold when comparing highest vs. lowest tertiles (OR = 0.19960, 95% CI=0.09-0.41, P=6.38E-07). CRISP3 was protective in both Lactobacillus and non-Lactobacillus dominant vaginal microbiomes (OR=0.39, 95% CI=0.19- 0.75, P=2.36E-3; OR=0.23,95%CI=0.12-0.43, P=4.11E-7, respectively). Similar estimates for CRISP3 and HIV were obtained in models adjusting for study arm, sexual behavior, and concurrent STIs. Using fluorescence immunohistochemistry, CRISP3 localized to the basal layer of the cervical epithelium. By flow cytometry, CRISP3 was highly expressed intracellularly in cervical neutrophils (CD66b+), including activated subsets (CD11b+CD62L-/ dim). Mucosal CRISP3 levels were negatively associated with activated cervical CD4+ T cells (CD3+CD4+CD38+HLA-DR+, r=-0.36, P=0.03), and higher CRISP3 expression was associated with innate immune and antiviral molecular pathways (P<0.001). Conclusion: CRISP3 is a mucosal neutrophil protein associated with lower risk of HIV infection, which may be mediated by reduced HIV target cell activation and innate antiviral immunity. More research on CRISP3 function and associated neutrophil phenotypes in the context of HIV prevention trials and strategies is warranted.

433

Poster Abstracts

435

CROI 2024 108