Modification of the HIV-specific CD8+ T-cell response in an HIV elite controller after chikungunya virus infection

Travelling with HIV in the XXI century: Case report and narrative review

The number of migrants and travellers has grown in recent decades. This phenomenon is also true of people living with HIV, given their much-improved life expectancy and quality of life. A significant number of travellers with HIV are migrants returning to their home countries to visit friends and relatives (VFRs). This population constitutes a high-risk group because they travel for longer and often to rural and remote areas and have closer contact with the local population. In this review we discuss the sociodemographic characteristics of travellers with HIV, the differences between conventional travellers and VFRs, and the risks of HIV acquisition and transmission during travel. We also present the most relevant travel-associated illnesses and highlight the particularities of pre-travel advice given to this population, including immunosuppression, responses to vaccines, high incidence of comorbidities, drug interactions, legal and language barriers. The need to integrate these factors based on far less evidence than that available for the general population makes pre-travel advice for travellers with HIV genuinely challenging.

The effects of chikungunya virus infection on people living with HIV during the 2014 Martinique outbreak

Our objective was to describe the clinical presentation of chikungunya virus (CHIKV) infection in patients living with HIV (PLHIV) during the 2014 Martinique outbreak. During the outbreak and the 6 following months, all PLHIV coming in our unit for a medical evaluation answered questions about potential CHIKV related symptoms, and had blood tests to assess the diagnosis. For patients coming in at the acute phase of infection, we are able to provide and analyze CD4+, CD8+ T-cells and HIV viral load evolution before, during and after CHIK infection. Among the 1 003 PLHIV in care in the center at the time of the outbreak, 188 (94 men and 94 women) had confirmed (following the WHO definition) CHIKV infection. Clinical presentation was common in 63% of the cases, severe and atypical forms were scarce. During the acute phase, CD4+ and CD8+ T-cells (evaluated in 30 PLHIV, 15 men and 15 women) absolute numbers dropped significantly, but returned to pre-CHIKV values after the acute phase. Reassuringly, CD4 and CD8 T cells proportions did not decrease during the acute phase. CHIKV infection had no significant impact on this anti-retroviral treated population.

PD-1 Expression in HIV-Specific CD8+ T cells Before Antiretroviral Therapy Is Associated With HIV Persistence

BACKGROUND

The persistence of latently infected T cells remains the principal barrier to HIV cure. Understanding how the early immune responses shape persistence of HIV on antiretroviral therapy (ART) will be fundamental for potential eradication. Here, we aimed to determine the relationship between CD8 T-cell function and phenotype before therapy and HIV persistence on ART.

METHODS

Blood samples from 29 individuals enrolled during primary HIV infection (at baseline and every 3 months up to 2 years post-ART initiation) were obtained. HIV-specific T-cell function and expression of the activation markers were evaluated before ART by flow cytometry. Cell-associated HIV DNA and unspliced (US)-RNA were quantified in purified CD4 T cells by real-time polymerase chain reaction. Data were analyzed using nonparametric statistics.

RESULTS

Elevated immune activation, dominance of monofunctional CD8 T cells, and skewed distribution of memory profile were observed before ART. After ART initiation, HIV DNA and US-RNA levels rapidly diminished, reaching a plateau by 30 weeks after ART. The proportion of baseline HIV-specific effector memory and terminal effector CD8 T cells directly correlated with HIV DNA levels at 1 year after ART. A strong positive correlation was observed between the proportion of bulk and HIV-specific PD-1 CD8 T cells measured before ART and HIV DNA at 1 year after ART.

CONCLUSIONS

A higher proportion of terminally differentiated CD8 T cells and increased PD1 expression were associated with HIV persistence on ART after treatment of primary infection. Thus, the quality of the early CD8 T-cell immune response may serve as a predictor of HIV persistence on ART.

Phenotype, Polyfunctionality, and Antiviral Activity of in vitro Stimulated CD8+ T-Cells From HIV+ Subjects Who Initiated cART at Different Time-Points After Acute Infection

Since anti-HIV treatment cannot cure the infection, many strategies have been proposed to eradicate the viral reservoir, which still remains as a major challenge. The success of some of these strategies will rely on the ability of HIV-specific CD8+ T-cells (CD8TC) to clear reactivated infected cells. Here, we aimed to investigate the phenotype and function of in vitro expanded CD8TC obtained from HIV+ subjects on combination antiretroviral therapy (cART), either initiated earlier (median = 3 months postinfection, ET: Early treatment) or later (median = 20 months postinfection, DT: Delayed treatment) after infection. Peripheral blood mononuclear cells from 12 DT and 13 ET subjects were obtained and stimulated with Nef and Gag peptide pools plus IL-2 for 14 days. ELISPOT was performed pre- and post-expansion. CD8TC memory/effector phenotype, PD-1 expression, polyfunctionality (CD107a/b, IFN-γ, IL-2, CCL4 (MIP-1β), and/or TNF-α production) and antiviral activity were evaluated post-expansion. Magnitude of ELISPOT responses increased after expansion by 103 times, in both groups. Expanded cells were highly polyfunctional, regardless of time of cART initiation. The memory/effector phenotype distribution was sharply skewed toward an effector phenotype after expansion in both groups although ET subjects showed significantly higher proportions of stem-cell and central memory CD8TCs. PD-1 expression was clustered in HIV-specific effector memory CD8TCs, subset that also showed the highest proportion of cytokine-producing cells. Moreover, PD-1 expression directly correlated with CD8TC functionality. Expanded CD8TCs from DT and ET subjects were highly capable of mediating antiviral activity, measured by two different assays. Antiviral function directly correlated with the proportion of fully differentiated effector cells (viral inhibition assay) as well as with CD8TC polyfunctionality and PD-1 expression (VITAL assay). In sum, we show that, despite being dampened in subjects on cART, the HIV-specific CD8TC response could be selectively stimulated and expanded in vitro, presenting a high proportion of cells able to carry-out multiple effector functions. Timing of cART initiation had an impact on the memory/effector differentiation phenotype, most likely reflecting how different periods of antigen persistence affected immune function. Overall, these results have important implications for the design and evaluation of strategies aimed at modulating CD8TCs to achieve the HIV functional cure.