Editor's evaluation: Identification of HIV-reservoir cells with reduced susceptibility to antibody-dependent immune response
Year: 2022
Type: peer-review
Abstract: Article Figures and data Abstract Editor's evaluation Introduction Results Discussion Materials and methods Data availability References Decision letter Author response Article and author information Metrics Abstract Human immunodeficiency virus (HIV) establishes a persistent infection in heterogeneous cell reservoirs, which can be maintained by different mechanisms including cellular proliferation, and represent the main obstacle to curing the infection. The expression of the Fcγ receptor CD32 has been identified as a marker of the active cell reservoirs in people on antiretroviral therapy (ART), but if its expression has any role in conferring advantage for viral persistence is unknown. Here, we report that HIV-infected cells expressing CD32 have reduced susceptibility to natural killer (NK) antibody-dependent cell cytotoxicity (ADCC) by a mechanism compatible with the suboptimal binding of HIV-specific antibodies. Infected CD32 cells have increased proliferative capacity in the presence of immune complexes, and are more resistant to strategies directed to potentiate NK function. Remarkably, reactivation of the latent reservoir from antiretroviral-treated people living with HIV increases the pool of infected CD32 cells, which are largely resistant to the ADCC immune mechanism. Thus, we report the existence of reservoir cells that evade part of the NK immune response through the expression of CD32. Editor's evaluation Persistence of the viral reservoir is hampering HIV cure. This study describes a possible way that HIV-infected cells in the reservoir may escape antibody killing. The findings show that reservoir cells tend to have less of a receptor that binds HIV antibodies capable of cell killing – these cells may then have a survival advantage as they are less susceptible to antibody killing. The study suggests that they also seem to be susceptible to proliferation, which helps maintain the reservoir. These studies provide evidence for one way in which the HIV reservoir is maintained. https://doi.org/10.7554/eLife.78294.sa0 Decision letter Reviews on Sciety eLife's review process Introduction HIV establishes a persistent infection for which, nowadays, there is no available cure. Despite huge advances on the optimization of ART, which leads to suppression of viral replication, ART does not fully eliminate the virus from the human body nor can completely solve the persistent inflammation caused by HIV (Klatt et al., 2013). Importantly, ART discontinuation leads to viral rebound from diverse anatomical sites and cell subsets containing replication-competent viruses (Grau-Expósito et al., 2017; Jost and Altfeld, 2012; Madhavi et al., 2015) representing the main obstacle in achieving cure (Joos et al., 2008). The HIV reservoir has a complex and heterogeneous nature, where each of the subsets that compose the viral reservoir contributes differently to viral persistence (Gálvez et al., 2021; Astorga-Gamaza and Buzon, 2021); i.e., central memory cells are one of the main populations contributing to the total reservoir size (Chomont et al., 2009), effector memory cells support HIV transcription (Grau-Expósito et al., 2017) and contain higher proportions of intact viral regions (Duette et al., 2022; Musick et al., 2019; Hiener et al., 2017), and memory stem cells and resident memory T cells are potentially long-lived niches for HIV (Buzon et al., 2014; Cantero-Pérez et al., 2019). Unfortunately, knowledge on the establishment, maintenance, and composition of the reservoir remains incomplete, and the identification of markers to exclusively target persistent HIV-infected cells remains elusive (Darcis et al., 2019; Neidleman et al., 2020). In this regard, the molecule CD32, a low-affinity receptor for the constant fraction of immunoglobulin G (FcγR-IIa), was proposed as a marker of HIV reservoir cells (Descours et al., 2017). While those results were questioned later by the identification of experimental artifacts (Bertagnolli et al., 2018; Pérez et al., 2018), several new studies partially corroborated the original findings; higher levels of viral DNA within the TCD32 population were reported after applying a very stringent cell isolation protocol (Darcis et al., 2020) and CD32 was identified as a marker of transcriptionally active persistent HIV-infected cells, both in blood and in the main reservoir tissues, namely the lymph nodes and the gastrointestinal tract (Cantero-Pérez et al., 2019; Abdel-Mohsen et al., 2018; Badia et al., 2018; Vásquez et al., 2019; Noto et al., 2018). Importantly, whether or not CD32 is a marker of latent or transcriptionally active infection, infected CD4+ T cells expressing CD32 contain replication-competent HIV and are found in long-term ART-treated people living with HIV (PLWH) (Cantero-Pérez et al., 2019; Descours et al., 2017; Darcis et al., 2020; Abdel-Mohsen et al., 2018; Badia et al., 2018; Vásquez et al., 2019; Martin et al., 2018). The cell markers CD20 (Serra-Peinado et al., 2019) and CD30 (Hogan et al., 2018) have been shown to also identify transcriptionally active HIV cells in samples from ART-suppressed PLWH. Whether these transcriptionally active HIV-infected cells persist in the body and are not targeted by host immune responses remains unknown. NK cells are lymphocytes that can eliminate cancer cells or virally-infected cells without prior antigen sensitization. They constitute an important arm of the immune system, not only by a direct cytotoxic effect on aberrant cells but also by the modulation of the adaptive immune responses. NK cells kill target cells by several mechanisms, such as natural cytotoxicity (NC), recognizing stress ligands expressed on the surface of infected cells, or by ADCC, driven by antibodies that bind to target cells (Vivier et al., 2008). The decision of NK cells to kill or not to kill a target cell depends on the balance between activating and inhibitory signals received from the interaction with the target cell (Lanier, 2008). Among relevant NK receptors, we find NC receptors such as NKp46, NKp30, NKp44, different Killer-cell immunoglobulin-like (KIRs), and lectin-like receptors such as NKG2A or NKG2C. Other important activating receptors for NK activity are NKG2D and DNAM-1, whose known ligands are the major histocompatibility complex (MHC) class I-related molecules MICA/B, and the UL16-binding proteins or CD155 and CD112, respectively. Further, expression of the inhibitory receptor NKG2A is known to impact NK effector responses through its interaction with HLA-E molecules (Bottino et al., 2005). In this sense, therapeutic interventions blocking this interaction represent promising tools to potentiate NK cell immune responses during different pathologies (André et al., 2018; Pereira et al., 2019). Importantly, HIV infection causes NK cell dysfunction, which is not completely restored by ART (Nabatanzi et al., 2019; Lichtfuss et al., 2012). NK cells play an important role in containing viral replication during early infection and shaping adaptive immune responses during chronic infection (Flórez-Álvarez et al., 2018). However, the role of NK cells in controlling the viral reservoir in PLWH on ART remains undefined. Mounting evidence supports the importance of NK cell function in shaping the HIV reservoir size, for example, through the induction of interferon (IFN-ɤ) and the expression of certain activating receptors (Marras et al., 2017). Moreover, proportions of NK cells inversely correlated with HIV-1 DNA reservoir levels in a clinical study designed to disrupt viral latency (Olesen et al., 2015). Importantly, during chronic infection, several strategies used by HIV to evade NK cell immune responses have been described, including the modulation of HLA class I molecules expression at the surface of infected cells (Jost and Altfeld, 2012). However, immune evasion mechanisms of HIV-infected reservoir cells to NK cell-mediated killing have not been identified. Here, we show that CD32 expression on HIV-infected cells confers a reduced susceptibility to NK cell-mediated ADCC killing by a mechanism compatible with a reduced binding of HIV-specific antibodies required for this mechanism. Importantly, this immune-resistant mechanism is also observed in latently HIV-infected cells from ART-treated PLWH after viral reactivation, providing a plausible explanation for the maintenance of transcriptionally active HIV-infected cells in ART-treated PLWH. Results Susceptibility of HIV-reservoir cell subsets to NK immune response While it is clear that ADCC, largely mediated by NK cells, is an important protective mechanism against HIV and simian immunodeficiency virus (SIV) infection (Alpert et al., 2012; Pollara et al., 2011; Haynes et al., 2012), the capacity of this immune mechanism to limit the infection of different T cell subsets composing the viral reservoir is currently unknown. Thus, we first assessed the intrinsic susceptibility of Naïve (TNA), Stem Cell Memory (TSCM), Central Memory (TCM), Effector Memory (TEM), TCD20dim, and TCD32dim CD4+ T cell subsets to ADCC response. Gp120-coated CD4+ T cells from 15 ART-treated and virologically-suppressed PLWH (participants #8–22, Supplementary file 1) were subjected to a flow cytometry-based ADCC assay (Gómez-Román et al., 2006). In this assay, we used gp120-coated primary CD4+T cells, and plasma from an HIV-infected person with a high titer of HIV-specific immunoglobulins, which allowed a comparative evaluation of the intrinsic susceptibility of the different subpopulations to NK-mediated killing. Gating of CD32 cells was performed as previously reported in our previous publications (Grau-Expósito et al., 2017), whereby possible contaminant cell conjugates with monocytes or B cells (defined as CD4+ CD32high cells), were excluded. Coating efficiency with the recombinant protein gp120 of different cell subsets is shown in Figure 1—figure supplement 1A, and a representative gating strategy used for the identification of killed cells by ADCC is shown in Figure 1—figure supplement 1B. Results showed that each CD4+ T cell subset had a different susceptibility to autologous NK cells, being TEM >TCM > TCD20dim>TNA>TSCM>TCD32dim more prone to be killed (ANOVA Friedman test p=0.0001) (Figure 1A). Overall, most CD4+T cell subsets were susceptible to ADCC, however TCD32dim cells, and to a lesser extent TSCM, showed the highest resistance to ADCC. Figure 1 with 2 supplements see all Download asset Open asset Susceptibility of CD4+ T cell subsets to the Natural Killer (NK) immune response. The susceptibility of different cell subpopulations that compose the HIV-reservoir to Natural Cytotoxicity (NC) and Antibody-Dependent Cell Cytotoxicity (ADCC) mediated by NK cells was measured by performing functional assays. (A) Percentage of gp120-coated cells killed by ADCC after being exposed to HIV-specific immunoglobulins (Igs) in the presence of NK cells. The intrinsic susceptibility to ADCC was measured in Naïve (TNA), Stem Cell Memory (TSCM), Central Memory (TCM), Effector Memory (TEM), TCD32dim, and TCD20dim subsets. Statistical comparisons were performed using the ANOVA Friedman with Dunn’s multiple comparison test. Median with interquartile range is shown. (B) Percentage of total gp120-coated CD4+ T cells from different cohorts of patients killed by ADCC. Healthy donors (HD), Elite Controllers (EC), and antiretroviral-treated (ART) PLWH. Statistical comparisons were performed using one-way ANOVA with Tukey’s multiple comparison test. Median with interquartile range are shown. (C) Percentage of cell subsets killed by ADCC in cells from HD, EC, and ART. Statistical comparisons were performed using the one-way ANOVA with Tukey’s multiple comparison test. Median with interquartile range is shown. (D–E) Spearman correlations between the size of the HIV-reservoir measured as total HIV-DNA in samples from ART-suppressed PLWH, and the potency of autologous NK cells to kill (D) total CD4+ T cells or (E) TCD32dim cells by ADCC. (F) Representative flow cytometry gating strategy used to quantify HIV infection after ex vivo infection with BaL or NL4.3. Fluorescence minus one (FMO) control was used to determine CD32 expression. Cells were infected for 5 days and the frequency of expression of CD32 on HIV-infected cells was measured for each condition. (G) Percentage of killing by NC of ex vivo HIV-infected TCD32dim and TCD32− cells mediated by autologous NK cells from ART-treated PLWH (n=14). Killing was calculated by normalizing the proportion of each subset within the p24+ fraction in the co-culture condition to the basal condition. (H) Percentage of ADCC killing of ex vivo HIV-infected TCD32dim and TCD32− cells mediated by autologous NK cells from ART-treated PLWH (n=14). Killing was calculated by normalizing the proportion of each subset within the p24+ fraction in the co-culture condition with plasma to the co-culture without plasma. Statistical comparisons were performed using the Wilcoxon matched-pairs signed-rank test. *p<0.05; **p<0.01. Figure 1—source data 1 This file contains the source data used to generate Figure 1. https://cdn.elifesciences.org/articles/78294/elife-78294-fig1-data1-v2.xlsx Download elife-78294-fig1-data1-v2.xlsx To address if the pattern observed for CD32 cells was exclusive of ART-treated PLWH, we included samples from Elite controllers (EC) and healthy donors (HD). First, we compared the expression of CD32 in CD4+ T cells in the three cohorts (participants #1–22, Supplementary file 1), following a very stringent flow cytometry gating strategy (Figure 1—figure supplement 1B). In agreement with previous studies (Darcis et al., 2020; Abdel-Mohsen et al., 2018; Holgado et al., 2018; García et al., 2018), we found that a median of 1.21% of CD4+ T cells expressed the CD32 receptor, and no statistically significant differences were detected between ART-suppressed, EC participants and HD (Figure 1—figure supplement 1C). In addition, and in concordance with the study of García et al., but differing from the report of Darcis et al. (Darcis et al., 2020; García et al., 2018), there was no correlation between the HIV-DNA or HIV-RNA levels and the frequency of CD32 expression on CD4+ T cells (Figure 1—figure supplement 1D–E). We then performed the NK-ADCC assays. We observed that overall, NK cells from healthy donors were highly efficient at killing the total CD4+ T cell population (Figure 1B) and the different CD4+ T subsets (Figure 1C). EC represented a heterogeneous group of individuals, in which no significant differences were detected compared to HD as a total (Figure 1B) or by subset (Figure 1C). Of note, we observe a highly variable functionality of NK cells in the EC cohort compared with HD. We hypothesize that this variability in the EC cohort may be due to a higher diversity in the expression of NK receptors among individuals. More research is needed in this regard. Total CD4+ T cells (Figure 1B) as well as all subsets from ART-treated PLWH were less susceptible to ADCC-mediated killing than HD (Figure 1C). The altered frequencies, phenotypes, and decreased functions of NK cell subsets reported during HIV infection (Mikulak et al., 2017), which are not fully restored by ART (Lichtfuss et al., 2012), could explain the different NK potency observed in these ART-suppressed PLWH. Notably, and regardless of that, NK cells from all cohorts showed a marked impaired capacity to kill TCD32dim cells (median % of ADCC of 0.00, 34.84, and 45.01, for ART, EC, and HD, respectively) (Figure 1C and Figure 1—figure supplement 1F–G). We also investigated the potential relationship between the total cell reservoir size in vivo and ADCC activity. We observed a statistically significant inverse correlation between the percentage of ADCC activity against CD4+ T cells and the total HIV-DNA reservoir size (Figure 1D) and, in particular, for the ADCC against TCD32dim cells (Figure 1E). HIV proteins are known to alter the expression of molecules on the infected cells, thereby impacting their recognition and likely the killing mediated by immune cells. Thus, we ought to confirm our results in a more physiological setting using ex vivo infected CD4+ T cells. Isolated CD4+ T cells from ART-suppressed PLWH were infected with HIVBaL or HIVNL4.3, and after 5 days, were subjected to NK NC and ADCC assays (participants #23–29, 36, 44, 46–49, and 51, Supplementary file 1). A representative flow gating strategy is shown in Figure 1F. After the ex vivo infection of CD4+ T cells, we observed higher expression of the CD32 molecule in comparison to uninfected cells (Figure 1—figure supplement 2A–B). Moreover, no significant differences between the killing of TCD32dim and TCD32− by NC in ART-suppressed PLWH were observed (Figure 1G). However, and in concordance with results in Figure 1A and C, TCD32dim cells from ART-suppressed PLWH were significantly more resistant to ADCC in comparison to their negative cell counterparts (median % ADCC killing normalized to NC of 19.66 vs 35.85 for TCD32dim and TCD32−, respectively) (Figure 1H). In addition, we observed that the capacity to kill infected TCD32dim cells was directly related to the global capacity to kill all infected cells, indicating the essential role of NK potency, in addition to the intrinsic susceptibility of the target cells (Figure 1—figure supplement 2C). These results show that, regardless of differences between individuals on the overall killing capacity of their NK cells, different subpopulations of infected CD4+ T cells have distinct intrinsic susceptibility to ADCC responses, being the pool of CD4+ T cells expressing the CD32 molecule more resistant. Moreover, ART-suppressed individuals, most likely due to the existence of impaired NK cells, have a remarkable inability to kill this population of infected cells. Viral-reactivated cells expressing CD32 from ART-treated PLWH are resistant to NK cell-mediated cytotoxicity Next, we examined if this NK-resistant profile might also affect the latent reservoir after viral reactivation. First, using samples from nine ART-suppressed PLWH (subjects #59–67, Supplementary file 1), we reactivated primary CD4+ T cells with different latency-reversing agents (LRA) and applied the Prime Flow RNA (FISH-flow) in situ hybridization (ISH) assay, which allows detecting at a single cell level cells expressing viral RNA, as described before (Grau-Expósito et al., 2017; Grau-Expósito et al., 2019). The gating strategy is shown in Figure 2—figure supplement 1A. We observed a higher increase of HIV-RNA+ cells in the TCD32dim fraction compared to TCD32− cells in all conditions and, within TCD32dim cells, HIV-RNA+ cells were more frequent after Romidepsin treatment compared to untreated cells (Figure 2A). Upregulation of CD32 expression upon the treatment with several LRAs was evidenced in total CD4+ T cells (Figure 2—figure supplement 1B). Furthermore, we performed functional NK assays using samples from 22 additional ART-suppressed PLWH after reactivation of the natural HIV reservoir (participants #68–89, Supplementary file 1). First, we evaluated viral reactivation by intracellular p24 detection in CD4+ T cells (Figure 2—figure supplement 1C) and successfully observed viral reactivation of dormant HIV in 17 of these samples (Figure 2B). An example of p24 detection using this functional assay is shown in Figure 2—figure supplement 1D. Also in line with our previous results, we found a higher frequency of viral reactivated cells (p24+ cells) within the TCD32dim fraction (Figure 2C). After the NK killing assays, viral-reactivated cells, in general, were susceptible to ADCC (Figure 2D, ART+LRA+NK+plasma condition) with a median of 30% increase in the ADCC activity compared with the NC activity (Figure 2E). Of note, we used autologous plasma from the same virologically-suppressed PLWH (mean time of undetectable viremia of 60 months [range 25–118]). This is noteworthy since ART treatment may decrease the number of antibodies mediating ADCC (Madhavi et al., 2015). We next evaluated the population of viral-reactivated cells expressing CD32 in these PLWH. We observed an increase in the expression of CD32 after latency disruption, which constituted a significant fraction of the total pool of viral reactivated cells (Figure 2F). Remarkably, this population was refractory to ADCC and even increased after the ADCC assays (condition with plasma) (Figure 2G). Thus, concordantly with previous results, TCD32dim cells showed a higher pattern of ADCC resistance compared to the total HIV-reactivated cells (Figure 2H). Altogether, our results show that the latent HIV reservoir expresses CD32 upon viral reactivation with LRAs, and the resulting TCD32dim-infected cells are less sensitive to NK-mediated ADCC killing than the whole infected population. Importantly, antibodies endowed with ADCC-triggering capacity are still present in some ART-suppressed PLWH, yet the TCD32dim population might escape from this immune mechanism. Figure 2 with 1 supplement see all Download asset Open asset Expression of HIV in TCD32dim reservoir cells after latency disruption and susceptibility to natural killer (NK) immune responses. Data from the direct ex vivo reactivation of the natural HIV reservoir in ART-suppressed PLWH. (A) Percentage of HIV-RNA expressing cells, measured by the RNA FISH-flow assay, within the TCD32dim and TCD32− subsets after viral reactivation with Ingenol, PMA/ionomycin, or romidepsin (n=9). Statistical comparisons were performed using the Wilcoxon matched-pairs signed-rank test (comparison between CD32dim and CD32− within each drug condition), and the ANOVA Friedman with Dunn’s multiple comparison test (comparison between different drug conditions of the cell subset). Median with interquartile range is represented. (B) Percentage of p24+ cells after 18 viral reactivation with is represented by a different Statistical comparisons were performed using the Wilcoxon matched-pairs signed-rank test. (C) of viral reactivation within the total pool of TCD32dim and TCD32− cells Statistical comparisons were performed using the Wilcoxon matched-pairs signed-rank test. (D) NK killing assays against viral reactivated cells. of p24+ cells CD4+ T cells after the addition of NK cells only or with the autologous plasma is shown Statistical comparisons were performed using the Wilcoxon matched-pairs signed-rank test. (E) Percentage of ADCC in p24+ cells normalized to the NC control Statistical comparisons were performed using (F) Percentage of CD32 expression within the total p24+ pool before and after HIV reactivation Statistical comparisons were performed using the Wilcoxon matched-pairs signed-rank test. (G) Percentage of TCD32dim within p24+ cells after HIV reactivation and functional NK-mediated assays Statistical comparisons were performed using the Wilcoxon matched-pairs signed-rank test. (H) Percentage of NK-mediated killing by ADCC of the reactivated TCD32dim or total p24+ cells ADCC was calculated as the of p24+ cells after the co-culture with NK and plasma and normalized to the condition with NK cells Statistical comparisons were performed using the Wilcoxon matched-pairs signed-rank test. *p<0.05; Figure data 1 This file contains the source data used to generate Figure Download Infected TCD32dim cells expressing activating or inhibitory NK ligands are more refractory to NK-mediated killing To if differences in could be for the impaired capacity of the NK cells to kill the TCD32dim we the expression of MICA/B, and HLA-E on the surface of HIV-infected CD4+ T cells after ex vivo infection. Of note, the impact of HIV infection on the expression of of these ligands is not fully and to on the viral and the of the viral infection et al., 2017; et al., Expression of the ligands was assessed by flow and the gating strategy used for these is shown in Figure supplement 1A. Overall, we observed that, HIV higher expression of MICA/B, and CD155 in infected cells compared to uninfected cells, only a proportion of infected cells expressed these activating ligands (Figure and In the HLA-E was found to be expressed in a significantly higher proportion of infected cells (median of in HIV-infected cells vs in uninfected cells, (Figure and CD4+ cells on their expression of CD32, the same was observed for the receptors MICA/B, or CD155 (median for infected TCD32dim vs for the infected TCD32− (Figure and However, HLA-E expression was significantly higher in HIV-infected TCD32dim compared to infected TCD32− cells (median of and and differences in were also detected (Figure and Of note, in the of any viral infection, TCD32dim cells showed higher HLA-E expression (Figure supplement 1B). Figure with 1 supplement see all Download asset Open asset Expression of in cells resistant to NK-mediated killing. HIV-infected cells from healthy donors were subjected to assays and the percentage of expression of different was measured by flow cytometry in different and of infected or uninfected cells. Expression of before performing the killing assays (A) Percentage of CD4+ T cells expressing and (B) Fluorescence for the expression of and CD155 on CD4+ T cells. (C) Percentage of CD4+ T cells expressing the molecule (D) for HLA-E expression on CD4+ T cells. show median with interquartile range and the comparisons were performed using the Wilcoxon matched-pairs signed-rank test (comparison between p24+ and as but HIV-infected CD32dim and cells. Expression of on HIV-infected cells not killed by the different Natural Cytotoxicity (NC) and Antibody-Dependent Cell Cytotoxicity Expression of on total infected CD4+ T cells before and after NK killing. Expression of on infected TCD32dim cells before and after NK killing. show median with interquartile shown in the represent ANOVA Friedman and the multiple comparison Dunn’s Figure data 1 This file contains the source data used to generate Figure Download Next, we ought to determine the expression of activating and inhibitory ligands on the fraction of CD4+ T cells refractory to ADCC after ex vivo infection. We performed both NC and ADCC functional assays cells from participants 44, and 51, Supplementary file 1). We observed statistically significant differences (ANOVA Friedman for the infected population expressing the ligands and CD155 after NC and ADCC assays (Figure only the cells expressing the in the NC and ADCC condition were different compared to the basal (Figure Of note, as previously reported et al., 2019; et al., cells expressing the molecule HLA-E were resistant to NK-mediated killing (Figure However, infected TCD32dim cells expressing any of the activating NK ligands were more refractory to both NK-mediated immune responses (Figure Overall, we observed that upon HIV infection, target cells expressing ligands showed some susceptibility to NK cells. However, infected cells expressing HLA-E and, CD32dim cells expressing this molecule the activating ligands MICA/B, and were more resistant to NK-mediated killing. binding of HIV-specific immunoglobulins to CD32 in HIV-infected cells NK cell might to explain TCD32dim cells are more resistant to ADCC. is a low-affinity receptor for the constant fraction of immunoglobulin G et al., et al., et al., and the expression of this molecule on HIV-infected cells provide with a capacity to with immunoglobulins present in both through their constant fraction or the variable In addition, immune molecules in and can bind to CD32 and with et al., 2008). Thus, the of such molecules or immune to the CD32 receptor might a advantage by infected cells from HIV-specific antibodies. we if HIV-specific immunoglobulins (Igs) were to bind to CD4+ T cells previously with After with plasma
Source: eLife
Author: Julie M Overbaugh
Institution: Fred Hutch Cancer Center
Language: English
Topic: HIV Research and Treatment
Subfield: Virology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,500
OpenAlex ID: W4293234133