Molecular mechanisms behind the generation of pro-oncogenic HIV-1 matrix protein p17 variants.

HIV-1 matrix protein p17 variants (vp17s), characterized by amino acid insertions at the COOH-terminal region of the viral protein, have been recently identified and studied for their biological activity. Different from their wild-type counterpart (refp17), vp17s display a potent B cell growth and clonogenic activity. Recent data have highlighted the higher prevalence of vp17s in people living with HIV-1 (PLWH) with lymphoma compared with those without lymphoma, suggesting that vp17s may play a key role in lymphomagenesis. Molecular mechanisms involved in vp17 development are still unknown. Here we assessed the efficiency of HIV-1 Reverse Transcriptase (RT) in processing this genomic region and highlighted the existence of hot spots of mutation in Gag, at the end of the matrix protein and close to the matrix-capsid junction. This is possibly due to the presence of inverted repeats and palindromic sequences together with a high content of Adenine in the 322-342 nucleotide portion, which constrain HIV-1 RT to pause on the template. To define the recombinogenic properties of hot spots of mutation in the matrix gene, we developed plasmid vectors expressing Gag and a minimally modified Gag variant, and measured homologous recombination following cell co-nucleofection by next-generation sequencing. Data obtained allowed us to show that a wide range of recombination events occur in concomitance with the identified hot spots of mutation and that imperfect events may account for vp17s generation.

Detection of HIV-1 matrix protein p17 in sera of viremic and aviremic patients.

People living with human immunodeficiency virus type 1 (HIV-1), even if successfully treated with a combined antiretroviral therapy, display a persistent inflammation and chronic immune activation, and an increasing risk of developing cardiovascular and thrombotic events, cancers, and neurologic disorders. Accumulating evidence reveals that biologically active HIV-1 proteins may play a role in the development of these HIV-1-associated conditions. The HIV-1 matrix protein p17 (p17) is released and accumulates in different organs and tissue where it may exert multiple biological activities on different target cells. To assess a role of p17 in different HIV-1-related pathological processes, it is central to definitively ascertain and quantitate its expression in a large number of sera obtained from HIV-1-infected (HIV-1+) patients. To this aim, we developed a specific and highly sensitive p17 capture immunoenzymatic assay. Data obtained highlight a heterogeneous expression of p17 in blood of tested patients, with patients who were negative or displayed from low to relatively high p17 blood concentrations (range from 0.05 to 7.29 nM). Moreover, we found that blood p17 concentration was totally independent from the viremic status of the patient. This finding calls for monitoring HIV-1+ patients in order to evaluate a possible correlation between p17 amount in blood and the likelihood of developing HIV-1-related pathological conditions.

A novel built-in adjuvant metallothionein-3 aids protein antigens to induce rapid, robust, and durable immune responses.

Adjuvants are crucial components of vaccines that can enhance and modulate antigen-specific immune responses. Herein, we reported for the first time that human metallothionein-3 (MT3), a low molecular weight cysteine-rich metal-binding protein, was a novel promising adjuvant candidate that could help protein antigens to induce rapid, effective, and durable antigen-specific immune responses. In the present study, MT3 was fused to outer membrane protein 19 (Omp19) of Brucella abortus (MT3-Omp19, MO) and C fragment heavy chain (Hc) of tetanus neurotoxin (MT3-Hc, MH), respectively. The results showed that MT3 as a built-in adjuvant increased the Omp19- or Hc-specific antibody responses by 100-1000 folds in seven days after primary immunization. Compared to other commercially available adjuvants, MT3 could stimulate earlier (4 days after primary injection) and stronger (10-100 folds) antibody response with lower antigen dose, and its adjuvanticity relied on fusion to antigen. Although the mechanism was not clear yet, the fusion protein MO was observed to directly activate DCs, promote germinal center formation and improve the speed of Ig class switching. Interestingly, our subsequent study found that other members of the mammalian MT family (human MT1 or murine MT3 for examples) also had potential adjuvant effects, but their effects were lower than human MT3. Overall, this study explored a new function of human MT3 as a novel built-in adjuvant, which may have important clinical application potential in vaccine development against global pandemics.

Antigenic molecular mimicry in viral-mediated protection from cancer: the HIV case.

BACKGROUND: People living with HIV/AIDS (PLWHA) show a reduced incidence for three cancer types, namely breast, prostate and colon cancers. In the present study, we assessed whether a molecular mimicry between HIV epitopes and tumor associated antigens and, consequently, a T cell cross-reactivity could provide an explanation for such an epidemiological evidence. METHODS: Homology between published TAAs and non-self HIV-derived epitopes have been assessed by BLAST homology. Structural analyses have been performed by bioinformatics tools. Immunological validation of CD8+ T cell cross-reactivity has been evaluated ex vivo by tetramer staining. FINDINGS: Sequence homologies between multiple TAAs and HIV epitopes have been found. High structural similarities between the paired TAAs and HIV epitopes as well as comparable patterns of contact with HLA and TCR α and ß chains have been observed. Furthermore, cross-reacting CD8+ T cells have been identified. INTERPRETATION: This is the first study showing a molecular mimicry between HIV antigens an TAAs identified in breast, prostate and colon cancers. Therefore, it is highly reasonable that memory CD8+ T cells elicited during the HIV infection may play a key role in controlling development and progression of such cancers in the PLWHA lifetime. This represents the first demonstration ever that a viral infection may induce a natural "preventive" anti-cancer memory T cells, with highly relevant implications beyond the HIV infection.

High expression of HIV-1 matrix protein p17 in both lymphoma and lymph node tissues of AIDS patients.

BACKGROUND: HIV-1 matrix protein p17 was found to be associated with lymphoma development in vitro. This study aimed to elucidate the pathogenetic roles of HIV-1 p17 in AIDS-related lymphoma. METHODS: Expression of HIV-1 proteins p17, p24, nef and tat were evaluated in tumor tissue samples from 60 lymphoma patients and lymph node samples from 23 non-lymphoma patients with HIV-1 infection by immunohistochemistry. Microvascular density (MVD) determined by CD34 were also assessed in tumor tissues. Clinicopathological data of AIDS patients with lymphoma were collected retrospectively. RESULTS: The subtypes of lymphoma among sixty AIDS patients were diffuse large B-cell lymphoma (32 cases), Burkitt lymphoma (23 cases), Hodgkin's lymphoma (4 cases), and plasmablastic lymphoma (1 case). The expression rate of HIV-1 p17 in lymphoma and non-lymphoma group was 63 % (38/60) and 61 % (14/29) respectively, with no significant difference (p = 0.835). The positive expression rate of p17 in both groups was significantly higher than that of p24, nef and tat (p < 0.05). The expression of p17 was associated with a higher MVD in the lymphoma group (p < 0.05). There were no significant differences in the 2-years overall survival between p17 positive and negative group (61 % vs. 50 %, p = 0.525). CONCLUSION: The common expression of HIV-1 matrix protein p17 in both lymphoma and lymph node tissues of AIDS patients and the association between p17 expression and the higher MVD suggest that the accumulation and persistence of p17 in tissues may play a role in lymphoma development.

HIV-1 mutants expressing B cell clonogenic matrix protein p17 variants are increasing their prevalence worldwide.

AIDS-defining cancers declined after combined antiretroviral therapy (cART) introduction, but lymphomas are still elevated in HIV type 1 (HIV-1)-infected patients. In particular, non-Hodgkin's lymphomas (NHLs) represent the majority of all AIDS-defining cancers and are the most frequent cause of death in these patients. We have recently demonstrated that amino acid (aa) insertions at the HIV-1 matrix protein p17 COOH-terminal region cause protein destabilization, leading to conformational changes. Misfolded p17 variants (vp17s) strongly impact clonogenic B cell growth properties that may contribute to B cell lymphomagenesis as suggested by the significantly higher frequency of detection of vp17s with COOH-terminal aa insertions in plasma of HIV-1-infected patients with NHL. Here, we expand our previous observations by assessing the prevalence of vp17s in large retrospective cohorts of patients with and without lymphoma. We confirm the significantly higher prevalence of vp17s in lymphoma patients than in HIV-1-infected individuals without lymphoma. Analysis of 3,990 sequences deposited between 1985 and 2017 allowed us to highlight a worldwide increasing prevalence of HIV-1 mutants expressing vp17s over time. Since genomic surveillance uncovered a cluster of HIV-1 expressing a B cell clonogenic vp17 dated from 2011 to 2019, we conclude that aa insertions can be fixed in HIV-1 and that mutant viruses displaying B cell clonogenic vp17s are actively spreading.

Sequence and vector shapes vaccine induced antibody effector functions in HIV vaccine trials.

Despite the advent of long-acting anti-retroviral therapy able to control and prevent infection, a preventative vaccine remains a global priority for the elimination of HIV. The moderately protective RV144 vaccine trial suggested functional IgG1 and IgG3 antibodies were a potential correlate of protection, but the RV144-inspired HVTN702 validation trial failed to demonstrate efficacy despite inducing targeted levels of IgG1/IgG3. Alterations in inserts, and antigens, adjuvant, and regimen also resulted in vaccine induced target quantitative levels of the immune correlates, but drove qualitative changes to the humoral immune response, pointing to the urgent need to define the influence of vaccine strategies on shaping antibody quality, not just quantity. Thus, defining how distinct prime/boost approaches tune long-lived functional antibodies represents an important goal in vaccine development. Here, we compared vaccine responses in Phase I and II studies in humans utilizing various combinations of DNA/vector, vector/vector and DNA/protein HIV vaccines. We found that adenoviral vector immunization, compared to pox-viral vectors, resulted in the most potent IgG1 and IgG3 responses, linked to highly functional antibody activity, including assisting NK cell related functions. Minimal differences were observed in the durability of the functional humoral immune response across vaccine regimens, except for antibody dependent phagocytic function, which persisted for longer periods in the DNA/rAd5 and rAd35/rAd5 regimen, likely driven by higher IgG1 levels. Collectively, these findings suggest adenoviral vectors drive superior antibody quality and durability that could inform future clinical vaccine studies. Trial registration: ClinicalTrials.gov NCT00801697, NCT00961883, NCT02207920, NCT00125970, NCT02852005).

HIV-1 matrix-tRNA complex structure reveals basis for host control of Gag localization.

The HIV-1 virion structural polyprotein, Gag, is directed to particle assembly sites at the plasma membrane by its N-terminal matrix (MA) domain. MA also binds to host tRNAs. To understand the molecular basis of MA-tRNA interaction and its potential function, we present a co-crystal structure of HIV-1 MA-tRNALys3 complex. The structure reveals a specialized group of MA basic and aromatic residues preconfigured to recognize the distinctive structure of the tRNA elbow. Mutational, cross-linking, fluorescence, and NMR analyses show that the crystallographically defined interface drives MA-tRNA binding in solution and living cells. The structure indicates that MA is unlikely to bind tRNA and membrane simultaneously. Accordingly, single-amino-acid substitutions that abolish MA-tRNA binding caused striking redistribution of Gag to the plasma membrane and reduced HIV-1 replication. Thus, HIV-1 exploits host tRNAs to occlude a membrane localization signal and control the subcellular distribution of its major structural protein.

Binding to PI(4,5)P2 is indispensable for secretion of B-cell clonogenic HIV-1 matrix protein p17 variants.

HIV-1 matrix protein p17 variants (vp17s) derived from non-Hodgkin's lymphoma (NHL) tissues of HIV-1-seropositive (HIV+) patients promote B-cell growth by activating the Akt signaling pathway. It is fundamental to understand the role played by vp17s in producing a microenvironment that fosters lymphoma development and progression. Therefore, we asked whether vp17s could be secreted from infected cells in their biologically active form. In this study, we show that two B-cell growth-promoting vp17s, NHL-a101 and NHL-a102, characterized by amino acid insertions at position 117 to 118 (Ala-Ala) or 125 to 126 (Gly-Asn), respectively, are secreted from HIV-1-infected Jurkat T cells during the active phase of viral replication. Secretion of biologically active vp17s also occurred in HeLa cells nucleofected with a plasmid expressing the entire Gag gene, following proteolytic cleavage of the Gag precursor polyprotein (Pr55Gag) by cellular aspartyl proteases. Binding of Pr55Gag to phosphatidylinositol-(4,5)-bisphosphate was indispensable for allowing the unconventional secretion of both wildtype p17 and vp17s. Indeed, here we demonstrate that inhibition of Pr55Gag binding to phosphatidylinositol-(4,5)-bisphosphate by using neomycin, or its enzymatic depletion achieved by overexpression of 5ptaseIV, significantly impair the secretion of p17s. We also demonstrated that heparan sulfate proteoglycans were involved in tethering p17s at the cell surface. This finding opens up an interesting way for investigating whether tethered p17s on the surface of HIV-1 reservoirs may represent a likely target for immune-mediated killing.

Effect of a confirmatory testing algorithm on early acute HIV diagnosis in Korea.

ABSTRACT: The 17 Provincial Institutes of Health and Environment (PIHEs) in Korea use HIV antibody, antigen, and Western blot assays for confirmatory testing of HIV infection. The Korea Disease Control and Prevention Agency (KDCA) has further included p24 antigen neutralization and nucleic acid tests (NATs) since 2015. Our study aimed to investigate the effect of this new testing algorithm on the confirmation rate of HIV infection.Annual changes, from 2012 through 2017, in positive or indeterminate HIV confirmatory results were compared for the two algorithms between the PIHEs and the KDCA. Fiebig stages and Western blot p31 band were used to identify the diagnostic proportions of acute or early chronic HIV for the two algorithms.The number of positive cases in the samples requested from PIHEs for reconfirmation by the KDCA has steadily increased from 10.3% in 2014 to 33.3% in 2017. However, the number of indeterminate cases dropped sharply, from 71.9% in 2014 to 14.0% in 2017. The results for the p31 reactive band were 27.4% and 88.4% for the KDCA and PIHEs, respectively. Of positive cases reported by the KDCA, 22.9% were in the early acute stage and Fiebig stages I to II.The new testing algorithm has improved the diagnosis of HIV infections in the early acute stage. Early confirmatory diagnosis can prevent secondary transmission of HIV and provide early treatment opportunities for people living with HIV infection.

Estimating HIV incidence in the Akwa Ibom AIDS indicator survey (AKAIS), Nigeria using the limiting antigen avidity recency assay.

INTRODUCTION: HIV incidence estimates are important to characterize the status of an epidemic, identify locations and populations at high risk and to guide and evaluate HIV prevention interventions. We used the limiting antigen avidity assay (LAg) as part of a recent infection testing algorithm to estimate HIV incidence in the Akwa Ibom AIDS Indicator Survey (AKAIS), Nigeria. METHODS: In 2017, AKAIS, a cross-sectional population-based study was conducted at the household (HH) level in 31 local government areas (LGAs) of Akwa Ibom state. Of the 8963 participants aged ≥15 years who were administered questionnaires for demographic and behavioural data, 8306 consented to HIV rapid testing. Whole-blood specimens were collected from 394 preliminary HIV-seropositive individuals for CD4+ cell count determination and plasma storage. Samples were shipped to a central quality laboratory for HIV confirmatory testing and viral load determination. A total of 370 HIV-positive specimens were tested for the recent HIV infection using the LAg assay. RESULTS: Of the 8306 consenting adults, the HIV prevalence was 4.8%. Of the 370 HIV-positive samples tested for HIV recency, the median age was 35 years, 48.8% had CD4+ cell count >500/mm3 and 81.3% was not virally suppressed. Viral suppression was greater among females (21%) than for males (13%). A total of 11 specimens were classified as recent based on the LAg assay and HIV viral load ≥1000 copies/mL. The weighted, adjusted HIV-1 incidence was 0.41/100 person-years (95% CI 0.16 to 0.66); translating to 13,000 new cases of HIV infections annually in Akwa Ibom, a state with a population of 5.5 million. The HIV incidence rate was similar in females and males (0.41% and 0.42% respectively). The incidence rate was the highest among participants aged 15 to 49 years (0.44%, 95% CI 0.15 to 0.74) translating to 11,000 new infections annually, about 85% of all new infections in the state. CONCLUSIONS: The finding of the high HIV incidence among the 15 to 49-year age group calls for renewed and innovative efforts to prevent HIV infection among young adults in Akwa Ibom state.

HIV p17 enhances T cell proliferation by suppressing autophagy through the p17-OLA1-GSK3ß axis under nutrient starvation.

Nutrient starvation is a common phenomenon that occurs during T cell activation. Upon pathogen infection, large amounts of immune cells migrate to infection sites, and antigen-specific T cells are activated; this is followed by rapid proliferation through clonal expansion. The dramatic expansion of cells will commonly lead to nutrient shortage. Cellular autophagy is often upregulated as a way to sustain the body's energy requirements. During infection, human immunodeficiency virus (HIV) co-opts a series of host cell metabolic pathways for replication. Several HIV proteins, such as Env, Nef, and Vpr, have already been reported as being involved in autophagy-related processes. In this report, we identified that the HIV p17 protein acts as a major factor in suppressing the autophagic process in T cells, especially under glucose starvation condition. HIV p17 interacts with Obg-like ATPase 1 (OLA1) and disrupts OLA1-glycogen synthase kinase-3 beta (GSK3ß) complex, leading to GSK3ß hyperactivation. Consequently, a prior proliferation of HIV-infected T cells under glucose starvation will occur. The inhibition of autophagy also aids HIV replication by antagonizing the antiviral effect of autophagy. Our study shows a new cellular pathway that HIV can hijack for viral spreading by a prior proliferation of HIV-loaded T cells and may provide new therapeutic targets for acquired immunodeficiency syndrome intervention.

B-cell clonogenic activity of HIV-1 p17 variants is driven by PAR1-mediated EGF transactivation.

Combined antiretroviral therapy (cART) for HIV-1 dramatically slows disease progression among HIV+ individuals. Currently, lymphoma represents the main cause of death among HIV-1-infected patients. Detection of p17 variants (vp17s) endowed with B-cell clonogenic activity in HIV-1-seropositive patients with lymphoma suggests their possible role in lymphomagenesis. Here, we demonstrate that the clonogenic activity of vp17s is mediated by their binding to PAR1 and to PAR1-mediated EGFR transactivation through Gq protein. The entire vp17s-triggered clonogenic process is MMPs dependent. Moreover, phosphoproteomic and bioinformatic analysis highlighted the crucial role of EGFR/PI3K/Akt pathway in modulating several molecules promoting cancer progression, including RAC1, ABL1, p53, CDK1, NPM, Rb, PTP-1B, and STAT1. Finally, we show that a peptide (F1) corresponding to the vp17s functional epitope is sufficient to trigger the PAR1/EGFR/PI3K/Akt pathway and bind PAR1. Our findings suggest novel potential therapeutic targets to counteract vp17-driven lymphomagenesis in HIV+ patients.

Evaluation of HIV-1 Regulatory and Structural Proteins as Antigen Candidate in Mice and Humans.

BACKGROUND: The diagnosis of HIV infection is important among different groups. Moreover, combination antiretroviral therapy is used to treat HIV-1, but it cannot eradicate the infection. Thus, the development of therapeutic vaccines, along with antiretroviral therapy, is recommended. This study evaluates the values of four HIV proteins as antigen candidates in therapeutic vaccine design as well as a possible diagnostic marker for HIV infection in humans. METHODS: In this study, the HIV-1 Tat and Rev regulatory proteins and structural Gp120 and p24 proteins were generated in E. coli expression system. Their immunogenicity was evaluated in BALB/ c mice using homologous and heterologous prime/boost strategies. Moreover, the detection of anti- HIV IgG antibodies against these recombinant proteins was assessed in untreated (Naïve/ HIV-infected), treated, and drug-resistant patients compared to the healthy (control) group as a possible diagnostic marker for HIV infection. RESULTS: In humans, our results showed that among HIV-1 proteins, anti-Gp120 antibody was not detected in treated individuals compared to the healthy (control) group. The levels of anti-Gp120 antibody were significantly different between the treated group and Naïve as well as drug-resistant subjects. Moreover, the level of anti-p24 antibody was significantly lower in the treated group than the Naive group. In mice, the results of immunization indicated that the Rev antigen could significantly induce IgG2a, IgG2b, and IFN-γ secretion aimed at Th1 response as well as Granzyme B generation as CTL activity in comparison with other antigens. Furthermore, the heterologous DNA prime/ protein boost regimen was more potent than the homologous regimen for stimulation of cellular immunity. CONCLUSION: Briefly, the levels of both anti-Gp120 and anti-p24 antibodies can be considered for the diagnosis of the HIV-infected individuals in different groups compared to the healthy group. Moreover, among four recombinant proteins, Rev elicited Th1 cellular immunity and CTL activity in mice as an antigen candidate in therapeutic vaccine development.

Priming with DNA Expressing Trimeric HIV V1V2 Alters the Immune Hierarchy Favoring the Development of V2-Specific Antibodies in Rhesus Macaques.

The RV144 vaccine trial revealed a correlation between reduced risk of HIV infection and the level of nonneutralizing-antibody (Ab) responses targeting specific epitopes in the second variable domain (V2) of the HIV gp120 envelope (Env) protein, suggesting this region as a target for vaccine development. To favor induction of V2-specific Abs, we developed a vaccine regimen that included priming with DNA expressing an HIV V1V2 trimeric scaffold immunogen followed by booster immunizations with a combination of DNA and protein in rhesus macaques. Priming vaccination with DNA expressing the HIV recombinant subtype CRF01_AE V1V2 scaffold induced higher and broader V2-specific Ab responses than vaccination with DNA expressing CRF01_AE gp145 Env. Abs recognizing the V2 peptide that was reported as a critical target in RV144 developed only after the priming immunization with V1V2 DNA. The V2-specific Abs showed several nonneutralizing Fc-mediated functions, including ADCP and C1q binding. Importantly, robust V2-specific Abs were maintained upon boosting with gp145 DNA and gp120 protein coimmunization. In conclusion, priming with DNA expressing the trimeric V1V2 scaffold alters the hierarchy of humoral immune responses to V2 region epitopes, providing a method for more efficient induction and maintenance of V2-specific Env Abs associated with reduced risk of HIV infection.IMPORTANCE The aim of this work was to design and test a vaccine regimen focusing the immune response on targets associated with infection prevention. We demonstrated that priming with a DNA vaccine expressing only the HIV Env V1V2 region induces Ab responses targeting the critical region in V2 associated with protection. This work shows that V1V2 scaffold DNA priming immunization provides a method to focus immune responses to the desired target region, in the absence of immune interference by other epitopes. This induced immune responses with improved recognition of epitopes important for protective immunity, namely, V2-specific humoral immune responses inversely correlating with HIV risk of infection in the RV144 trial.

Hepatoesplenomegalia relacionada a linfoma de Burkitt en paciente pediátrico / Hepatoesplenomegalia related to Burkitt´s lymphoma in a pediatric patient

RESUMEN El linfoma de Burkitt, se trata de un subtipo poco frecuente del linfoma no Hodgkin, con elevada frecuencia en aquellos pacientes con sida. La hepatoesplenomegalia es un signo clínico de gran importancia para el diagnóstico oportuno de algunas patologías; entre los mecanismos de formación de la hepatoesplenomegalia se encuentra la infiltración celular, ocasionada por la migración de células tumorales. Se presenta por inflamaciones debido a la presencia de infecciones por virus o bacterias las cuales son muy comunes en pacientes con sida. Se presentó un caso de un paciente masculino de 4 años, diagnosticado con VIH positivo, con la configuración correspondiente de criterios clínicos en clasificación C para sida. El cual desarrolló a nivel de cavidad oral un Burkitt primario, que se acompañó de hepatoesplenomegalia. Se pretendió describir la relación y el comportamiento de este tipo de linfoma con la hepatoesplenomegalia, así como la repercusión a nivel del sistema estomatognático, a nivel sistémico y el plan de tratamiento. Por el cuadro clínico e inmunológico del paciente estudiado, se planteó un pronóstico reservado por presentar un cuadro clínico infrecuente, en el que se observó Burkitt; tanto a nivel del sistema estomatognático como a nivel abdominal. Se hizo necesario realizar un diagnóstico oportuno y certero para iniciar el tratamiento a tiempo, se comenzó inmediatamente con tratamiento (AU).

ABSTRACT Burkitt lymphoma (BL) is a rare subtype of non-Hodgkin lymphoma, with high frequency in those patients with AIDS. Hepatosplenomegaly is a clinical sign of great importance for the timely diagnosis of some pathologies; cellular infiltration is found among the mechanisms of hepatosplenomegaly formation; it is caused by the migration of tumor cells. It emerges by inflammations due to the presence of infections by virus or bacteria which are very common in patients with AIDS. The authors present the case of a male patient, aged 4 years, with a positive HIV diagnosis, and the correspondent configuration of clinical criteria in C classification for AIDS, who developed a primary Burkitt lymphoma at the level of oral cavity We present the case of a 4-year-old male patient diagnosed with HIV positive, with the corresponding configuration of clinical criteria in classification C for AIDS; who developed a primary LB at the oral cavity level that was accompanied by hepatosplenomegaly. The authors pretended to describe the relation and behavior of this kind of lymphoma with hepatosplenomegaly, and also the repercussion at the stomatognathic level, at the systemic level and the treatment plan. Due to the clinical and immunological characteristics of the studied patient a reserved prognosis was given because of presenting infrequent clinical characteristics in which a Burkitt was observed both, at the stomatognathic and at the abdominal level. It was necessary to make an opportune and accurate diagnosis to begin the treatment on time (AU).

The evaluation of low cut-off index values of Elecsys® HIV combi PT assay in predicting false-positive results.

OBJECTIVE: To analyze the results of different cut-off index (COI) values of Elecsys® HIV combi PT assay and to assess the role of COI in reducing the frequency of false-positive results. METHODS: We conducted a retrospective study of samples analyzed by Elecsys® HIV combi PT assay, a 4th-generation ECLIA, between 2016 and 2017. A total amount of 379 122 samples were collected for HIV (Human Immunodeficiency Virus) screening. RESULTS: A total of 379 122 samples were analyzed. 2528 (0.67%) were positive by Elecsys® HIV combi PT. Of these, 468 were false-positive results, and most of them (94.87%) were in samples with 1 < COI < 15. The false-positive rate was 0.12%. Patients with false-positive samples were more distributed in elder (P < .001) and female (P < .001) than true-positive specimens. The median COI in true-positive specimens was (385.20), which is significantly higher than false-positive specimens (2.08). The consistency between Elecsys® HIV combi PT assay and 3rd-generation and positive predictive value (PPV) increased with higher COI values. Cancer, infection, and neurological diseases were considered the potential confounding factors of HIV false-positive results (19.44%, 11.11%, and 6.62%, respectively). CONCLUSION: Samples with low COI values, especially those contain confounding factors, need to be further scrutinized to determine whether the confounding factors may cause false-positive problem. In addition, the hypothesis that low COI values may predict false-positive results is valid.

Risks of requiring a dedicated molecular specimen for HIV diagnosis and a potential strategy for mitigation.

BACKGROUND: HIV screening (i.e. antigen/antibody) tests are followed by a supplemental (i.e. antibody-only) if the screen is positive. Discrepant results can result from two scenarios: a false-positive screening test or acute HIV infection. These scenarios can be distinguished by a molecular HIV test, but due to contamination concerns, our laboratory recently implemented a policy requiring a second specimen dedicated for molecular HIV testing. Our objective was to (1) characterize the effect of this policy on the time-to-diagnosis for patients with discrepant screening and supplemental test results, and (2) explore "strength of positivity" as an interim predictor of screening test accuracy while awaiting confirmatory test results. METHODS: Data from our laboratory information system, electronic health record, and instrument logs were used to collate data for all HIV testing performed at Barnes-Jewish Hospital (BJH) between January 1, 2014 and October 18, 2017. RESULTS: Requiring a dedicated specimen for molecular testing significantly increased the time-to-diagnosis for patients with discrepant screening and supplemental HIV tests (p = 0.0084). This policy also contributed to loss-to-followup, with 0/35 discrepant cases lost-to-followup prior to policy implementation compared to 2/10 after implementation. However, by optimizing the signal-to-cutoff (S/CO) ratio of the screening test, we were able to more accurately distinguish false-positives from acute-HIV prior to molecular testing (sensitivity of 100%, specificity of 89%). CONCLUSIONS: We propose utilizing quantitative fourth-generation assay results (S/CO) ratios as a predictor of infection true positivity in situations where the screening assay is reactive but the supplemental test is negative and confirmatory molecular results are not immediately available.

Immune Monitoring Reveals Fusion Peptide Priming to Imprint Cross-Clade HIV-Neutralizing Responses with a Characteristic Early B Cell Signature.

The HIV fusion peptide (FP) is a promising vaccine target. FP-directed monoclonal antibodies from vaccinated macaques have been identified that neutralize up to ∼60% of HIV strains; these vaccinations, however, have involved ∼1 year with an extended neutralization-eclipse phase without measurable serum neutralization. Here, in 32 macaques, we test seven vaccination regimens, each comprising multiple immunizations of FP-carrier conjugates and HIV envelope (Env) trimers. Comparisons of vaccine regimens reveal FP-carrier conjugates to imprint cross-clade neutralizing responses and a cocktail of FP conjugate and Env trimer to elicit the earliest broad responses. We identify a signature, appearing as early as week 6 and involving the frequency of B cells recognizing both FP and Env trimer, predictive of vaccine-elicited breadth ∼1 year later. Immune monitoring of B cells in response to vaccination can thus enable vaccine insights even in the absence of serum neutralization, here identifying FP imprinting, cocktail approach, and early signature as means to improve FP-directed vaccine responses.

An HIV Vaccine Targeting the V2 Region of the HIV Envelope Induces a Highly Durable Polyfunctional Fc-Mediated Antibody Response in Rhesus Macaques.

The HIV vaccine field now recognizes the potential importance of generating polyfunctional antibodies (Abs). The only clinical HIV vaccine trial to date to show significant efficacy (RV144) found that reduced infection rates correlated with the level of nonneutralizing Abs specific for the V2 region of the envelope glycoprotein. We have conducted a comprehensive preclinical reverse vaccinology-based vaccine program that has included the design and production and testing of numerous scaffolded V2 region immunogens. The most immunogenic vaccine regimen in nonhuman primates among those studied as part of this program consisted of a cocktail of three immunogens presenting V2 from different viruses and clades in the context of different scaffolds. Presently we demonstrate that the V2-specific Ab response from this regimen was highly durable and functionally diverse for the duration of the study (25 weeks after the final immunization). The total IgG binding response at this late time point exhibited only an ∼5× reduction in potency. Three immunizations appeared essential for the elicitation of a strong Ab-dependent cellular cytotoxicity (ADCC) response for all animals, as opposed to the Ab-dependent cellular phagocytosis (ADCP) and virus capture responses, which were comparably potent after only 2 immunizations. All functionalities measured were highly durable through the study period. Therefore, testing this vaccine candidate for its protective capacity is warranted.IMPORTANCE The only HIV vaccine trial for which protective efficacy was detected correlated this efficacy with V2-specific Abs that were effectively nonneutralizing. This result has fueled a decade of HIV vaccine research focused on designing an HIV vaccine capable of eliciting V2-focused, polyfunctional Abs that effectively bind HIV and trigger various leukocytes to kill the virus and restrict viral spread. From the numerous vaccine candidates designed and tested as part of our V2-focused preclinical vaccine program, we have identified immunogens and a vaccine regimen that induces a highly durable and polyfunctional V2-focused Ab response in rhesus macaques, described herein.