Background Immune checkpoint inhibitors (ICI) are approved for treatment of recurrent or metastatic oropharyngeal head and neck squamous cell carcinoma in the first- and second-line settings. However, only 15–20% of patients benefit from this treatment, a feature increasingly ascribed to the peculiar characteristics of the tumor immune microenvironment (TIME). Methods Immune-related gene expression profiling (GEP) and multiplex immunofluorescence (mIF) including spatial proximity analysis, were used to characterize the TIME of 39 treatment-naïve oropharyngeal squamous cell carcinomas (OPSCC) and the corresponding lymph node metastases. GEP and mIF results were correlated with disease-free survival (DFS). HPV-positive tumors disclosed a stronger activation of several immune signalling pathways, as well as a higher expression of genes related to total tumor-infiltrating lymphocytes, CD8 T cells, cytotoxic cells and exhausted CD8 cells, than HPV-negative patients. Accordingly, mIF revealed that HPV-positive lesions were heavily infiltrated as compared to HPV-negative counterparts, with a higher density of T cells and checkpoint molecules. CD8+ T cells appeared in closer proximity to tumor cells, CD163+ macrophages and FoxP3+ cells in HPV-positive primary tumors, and related metastases. In HPV-positive lesions, PD-L1 expression was increased as compared to HPV-negative samples, and PD-L1+ tumor cells and macrophages were closer to PD-1+ cytotoxic T lymphocytes. Considering the whole cohort, a positive correlation was observed between DFS and higher levels of activating immune signatures and T cell responses, higher density of PD-1+ T cells and their closer proximity to tumor cells or PD-L1+ macrophages. HPV-positive patients with higher infiltration of T cells and macrophages had a longer DFS, while CD163+ macrophages had a negative role in prognosis of HPV-negative patients. Conclusions Our results suggest that checkpoint expression may reflect an ongoing antitumor immune response. Thus, these observations provide the rationale for the incorporation of ICI in the loco-regional therapy strategies for patients with heavily infiltrated treatment-naïve OPSCC, and for the combination of ICI with tumor-specific T cell response inducers or TAM modulators for the “cold” OPSCC counterparts.

We described short-term HIV tropism changes occurring in peripheral blood mononuclear cells and the correlations with HIV DNA value in HIV-HCV co-infected patients cured for HCV disease and with undetectable HIV viremia or residual viremia (RV). Plasma HIV RNA, cellular HIV DNA and tropism were evaluated pre-HCV treatment (baseline, BL) and at 12(T1) and 24(T2) weeks after HCV treatment start. V3 sequences were interpreted using Geno2pheno and classified as R5 only if all three sequences had an FPR ≥ 10% and as X4 when at least one replicate sequence had an FPR < 10%. Forty-nine patients (21 with X4 and 28 with R5 virus) were enrolled. Five X4 patients and 9 R5 subjects experienced at least one tropism change,11 with RV:1/5 patients with X4 infection at BL switched at T1 versus 8/9 in the R5 group (p = 0.022977) and the difference was confirmed in subjects with RV (p = 0.02);6/9 R5 patients switching at T1 confirmed the tropism change at T2. No significant differences in HIV DNA values between patients with RV starting with a R5 or X4 tropism and experienced tropism switch or not were found. Short-term tropism switch involved almost a third of patients, in all but three cases with HIV RV. Being R5 at BL is associated to a higher instability, expressed as number of tropism changes and confirmed switch at T2.

Backgroundto evaluate circulation of drug resistance mutations (DRMs), sub-types (ST) and Herpesviruses replication among subjects recently diagnosed as HIV infected (pts) in Veneto (Italy), over 16 years, comparing previously reported trends with the most recent one, updated to 2019.Methodson plasma from 2919 patients diagnosed from July 2004 to April 2019, protease (PR), reverse transcriptase (RT) and recently Integrase (In) were analyzed for DRMs, susceptibility profile (Stanford db) and ST. Potential low-level resistances were excluded. CMV-DNA and EBV-DNA were evaluated by in-house Real-Time-PCR in PBMCs.Resultsin 5 periods (2004/06, 07/09, 10/12, 13/16, 17–19) 334, 796, 752, 750 and 287 patients were recruited; non-B-ST were 21.9, 29.3, 33, 32.7 and 48.1% (33.5% Italians in 17–19), respectively. A significant increase of non-B-ST (P < 0.0001 for trend) and of the percentage of Italians with non-B-strains (P = 0.029) were observed. Resistance to PR or to multiple classes declined but not to non-nucleoside RT inhibitors (NNRTI) (Fig 1). E138A alone, not included in the previous evaluations, increased from 2.3 to 1.8, to 3.2, to 3.6, to 4.7% in 2017-19. No primary TDRM to In-Inhibitors (InIn) were found in 469 B-ST-Pts enrolled in 2014–19; 16% had major TDRM for RT/PI. Among 231 non-B patients, 12,5% with other TDRMs, only a 143C and a 66I were found. Accessory InIn-TDRMs were detected (Figures 2 and 3). Nevertheless, from 2009 to 2019 in Veneto 114 InIn-failed and potentially transmitters patients with In-DRMs were found. In 2017–19 17,3% of patients had CMV-DNA in PBMCs, with a median CD4 of 55 (8%), HIV-RNA 247251 cps/mL and EBV-DNA of 811 cps/106 PBMCs (3% were neg); Patients CMV-DNA-negative (82,7%) had median CD4 of 334 (18,9%), HIV-RNA 47770 cps/mL and a significantly lower EBV-DNA of 194 cps/106 PBMCs (15% were neg): differences between immuvirological variables were significant.ConclusionAn increase of non-B strains and a slight increase of TDRMs among B-ST were observed. The persistent circulation of NNRTI-DRMs, the shortage of major In-TDRMs but a circulation of many In-polymorphisms have implications on the screening at baseline and on the selection of the first-line HAART. Many patients with lower CD4 and higher HIV replication has an incomplete control of co-infecting herpesviruses, which contribute to immunoactivation. Disclosures All authors: No reported disclosures.