CROI 2016 Abstract eBook

Abstract Listing

Poster Abstracts

732 CX3CR1+ CD8 T Cells Are Promoted by CMV Coinfection in Treated HIV Infection Michael L. Freeman 1 ; Joseph C. Mudd 2 ; Souheil-AntoineYounes 1 ; Soumya Panigrahi 1 ; Michael M. Lederman 1 1 Case Western Reserve Univ, Cleveland, OH, USA; 2 NIAID, NIH, Bethesda, MD, USA

Background: Activated CD8 T cells are prominent within atheromas. Their expansion is a hallmark of antiretroviral therapy (ART)-treated HIV infection and is linked to cardiovascular disease risk. We recently showed that co-infection with cytomegalovirus (CMV) is associated with heighted inflammation and is necessary for CD8 T cell expansion in ART-treated HIV-infection. Here we examined the influence of CMV co-infection on the phenotype and function of expanded CD8 T cells in ART-treated HIV infection. Methods: PBMCs were harvested from CMV-seropositive (n=15) or CMV-seronegative (n=10) HIV-infected persons. The activation status, function, and expression of the transcription factors T-bet and Eomes in distinct CD8 T cell maturation subsets were compared by flow cytometry. Memory CD8 T cells subsets were sorted from PBMCs and measured for their ability to produce IFNγ after T cell receptor-driven stimulation with anti-CD3/anti-CD28. Results: We identify a population of circulating CCR7 lo CD8 T cells that express the endothelial-homing receptor for fractalkine (CX3CR1), the thrombin receptor (PAR-1), and the platelet-binding receptor (PSGL-1). The percentage of CD8 T cells expressing CX3CR1 is negatively correlated with the CD4/CD8 ratio (rho=-0.5261, P=0.003). Frequencies of circulating CX3CR1+ CD8 T cells are significantly enriched in CMV-seropositive ART-treated HIV-infected subjects (40% of all memory CD8 T cells) when compared to frequencies of CX3CR1+ CD8 T cells in ART-treated HIV+ CMV-seronegative subjects (24%, P=0.004). A greater proportion of CCR7 lo CX3CR1 + CD8 T cells from CMV-seropositive HIV+ donors are CD28-negative (82% vs 47%, P=0.005), CD57 positive (47% vs 31%, P=0.010), and a have a T-bet hi Eomes lo phenotype (45% vs. 22%, P=0.003) compared to findings among CMV- seronegative HIV+ persons. IFNγ production following TCR stimulation was concentrated within the CX3CR1+CD57+ population. Conclusions: Here we identify a population of circulating cytokine-producing memory that are negatively correlated with CD4/CD8 ratio, that express endothelium-homing receptors and may contribute to cardiovascular disease risk in ART-treated HIV-infection. CX3CR1+ CD8 T cells are detectable in ART-treated, HIV-positive CMV-seronegative donors but are relatively and absolutely expanded in HIV/CMV co-infection, suggesting a role for inflammation in their development. 733 Baseline Sputum and Polyfunctional TB-Specific CD4+ T Cells in HIV-TB Coinfection David H. Canaday 1 ; Htin Aung 2 ; BrigidWilson 1 ; Harriet Mayanja-Kizza 3 ; Sophie Nalukwago 4 ; Joy Baseke 4 ; Michael R. Betts 5 ;W. H. Boom 2 1 Cleveland VA Med Cntr, Cleveland, OH, USA; 2 Case Western Reserve Univ, Cleveland, OH, USA; 3 Makerere Univ Coll of Hlth Scis, Kampala, Uganda; 4 Mulago Hosp, Kampala, Uganda; 5 Univ of Pennsylvania, Philadelphia, PA, USA Background: Assessing polyfunctionality of T cell function has become increasingly common in the TB field. What this means and how this correlates with disease states and diagnosis needs further exploration. Here we compare CD4+ T cell cytokine profiles and polyfunctionality in response to M. tuberculosis (MTB) antigen in relation to diagnostic tests at initial presentation in HIV+ subjects . Methods: 59 HIV+ persons age 14-60 (median 32) with CD4 counts >200 (median 544) were recruited in Kampala, Uganda. Subjects had PTB based on sputum smear and/or culture positivity. Baseline diagnostic sputum smear were graded 0-3 by WHO/ IUATLD categories. All subjects had chest x-ray (CXR). None had prior TB disease or were on ARV. Multicolor flow analysis was performed on PBMC stimulated with PPD, CMV antigen or SEB and frequencies of IL-2, IFN-gamma, TNF-alpha, and MIP1-alpha secreting CD4+ T cells were determined. Results: Subjects with baseline diagnostic sputum smear in lowest category of 0 compared to those with 1 or higher had reduced IFN, IL-2, or MIP after in vitro PPD stimulation (p=<0.03) but were similar to CMV and SEB stimulation. There is increased polyfunctionality to PPD (p=0.006) in those subjects with the higher baseline sputum smear grades. This relationship did not hold comparing polyfunctionality and disease extent based on CXR. There was no difference in polyfunctionality between the sputum smear groups with CMV or SEB stimulation. The extent of disease on CXR was at the lowest level in subjects with the lowest baseline sputum smear grade however there was no correlation between those with the lowest sputum smear grade and CD4 count or HIV viral load. Conclusions: These data suggest that subjects with the lowest amount of MTB in their sputum have both quantitatively and qualitatively different cytokine responses to PPD than those with greater levels of MTB burden. They also suggest that these differences are TB specific. There have been some observations in other systems that greater antigen loads provoke a more polyfunctional T cell response. Our data suggest that lower screening sputum smears have a lower load of MTB and generate a less polyfunctional T cells. It is not clear that the higher polyfunctionality associated with higher smear grade has an increased protective benefit since higher smear grades were associated with a greater extent of disease on CXR. Supported by AI80313, AI36219, and VA 734 Neutrophil-Derived MMP-8 Activity Is AssociatedWith Immunopathology in TB-IRIS Naomi F. Walker 1 ; KatalinWilkinson 2 ; Graeme Meintjes 3 ; Rene Goliath 3 ; Janique Peyper 3 ; Robert J.Wilkinson 1 ; Jon S. Friedland 1 ; PaulT. Elkington 4 1 Imperial Coll London, London, UK; 2 Francis Crick Inst Mill Hill Lab/Univ of Cape Town, Observatory, South Africa; 3 Univ of Cape Town, Cape Town, South Africa; 4 Univ of Southampton, Southampton, UK Background: Tuberculosis (TB) is the leading cause of death in HIV-infected patients. Anti-retroviral therapy (ART) reduces mortality but may be complicated by the paradoxical TB-immune reconstitution inflammatory syndrome (TB-IRIS). Diagnostic and targeted treatment strategies for TB-IRIS are lacking. We investigated the hypothesis that matrix metalloproteinases (MMPs), previously implicated in TB tissue destruction, associate with immunopathology in TB-IRIS. Methods: In a longitudinal study conducted at a HIV-TB clinic in Cape Town, HIV-infected ART-naïve patients, with CD4 counts <200 cells/mm 3 , presenting with pulmonary TB, were followed from TB treatment initiation (TB0), for the first 3 months of ART. Serial induced sputum and plasma were collected. MMP, cytokine and matrix degradation product procollagen III N-terminal propeptide (PIIINP) concentrations were quantified (pg/ml) at TB0, ART initiation (ARV0), week 2 (ARV2) and 4 (ARV4) of ART. Chest radiographs (CXR) were scored for disease extent. Patients who developed TB-IRIS were compared with those who did not (non-IRIS controls) using Mann-Whitney U test. Correlations were assessed using Spearman’s test. Results: 49 HIV-infected TB patients were recruited. 29 (59%) developed TB-IRIS, after a median of 14 days of ART. Median plasma PIIINP was higher in TB-IRIS patients than non-IRIS controls, at TB0 (43600 vs 21651 pg/ml, p=0.036), ARV2 (6104 vs 1095 pg/ml, p=0.043) and ARV4 (46763 vs 22424 pg/ml, p=0.001). Plasma MMPs were elevated in TB-IRIS patients, most significantly MMP-8. Median plasma MMP-8 was higher in TB-IRIS at all timepoints, with the greatest difference observed at TB0 (4582 vs 526 pg/ml, p=0.002) and at ARV2 (6140 vs1095 pg/ml, p=0.0007). Plasma MMP-8 correlated with plasma PIIINP (r=0.435, p<0.0001), neutrophil count (r=0.617, p<0.0001), C-reactive protein (r=0.67, p<0.0001) and heart rate (r=0.262, p=0.002), but not CXR score. Plasma MMP-1 and MMP-3 were also higher in TB-IRIS. In TB-IRIS, MMP-8 concentrations were 30-100 fold higher in plasma than in sputum at the corresponding timepoints. Conclusions: MMPs associate with pulmonary tissue destruction in TB. These new findings implicate systemic MMP dysregulation in TB-IRIS pathophysiology, suggesting that neutrophil-derived MMP-8 plays a key role and may be a therapeutic target. MMP-8 and PIIINP are also potential predictive and diagnostic markers of TB-IRIS.

Poster Abstracts

305

CROI 2016