Monocyte Gene and Molecular Expression Profiles Suggest Distinct Effector and Regulatory Functions in Beninese HIV Highly Exposed Seronegative Female Commercial Sex Workers.

We have previously reported that the female genital tract (FGT) of Beninese HIV highly-exposed seronegative (HESN) commercial sex workers (CSWs), presented elevated frequencies of a myeloid HLA-DR+CD14+CD11c+ population presenting "tolerogenic" monocyte derived dendritic cells (MoDC) features. In order to assess whether a differential profile of monocytes may be involved in the generation of these genital MoDCs, we have herein characterized the blood monocyte compartment of Beninese HESNs (HIV-uninfected ≥ 10 years CSWs) and relevant controls (HIV-uninfected 2.5-5 years CSWs herein termed "early HESNs"), HIV-infected CSWs, and low-risk HIV-uninfected women from the general population. Transcriptomic analyses by RNA-Seq of total sorted blood monocytes demonstrate that in comparison to the control groups, HESNs present increased expression levels of FCGR2C, FCAR, ITGAX, ITGAM, CR2, CD68, and CD163 genes, associated with effector functions. Moreover, we found increased expression levels of genes associated with protection/control against SHIV/HIV such as CCL3, CCL4, CCL5, BHLHE40, and TNFSF13, as well as with immune regulation such as IL-10, Ahr, CD83, and the orphan nuclear receptor (NR)4A1, NR4A2, and NR4A3. Through multicolor flow cytometry analyses, we noticed that the frequencies of intermediate and non-classical monocyte populations tended to be elevated in the blood of HESNs, and exhibited increased expression levels of effector CD16, CD11c, CD11b, as well as regulatory HLA-G, IL-10, and IFN-α markers when compared to HIV-uninfected women and/or HIV-infected CSWs. This profile is compatible with that previously reported in the FGT of HESNs, and likely confers an enormous advantage in their resistance to HIV infection.

Inverted CD8 T-Cell Exhaustion and Co-Stimulation Marker Balance Differentiate Aviremic HIV-2-Infected From Seronegative Individuals.

HIV-2 is less pathogenic compared to HIV-1. Still, disease progression may develop in aviremic HIV-2 infection, but the driving forces and mechanisms behind such development are unclear. Here, we aimed to reveal the immunophenotypic pattern associated with CD8 T-cell pathology in HIV-2 infection, in relation to viremia and markers of disease progression. The relationships between pathological differences of the CD8 T-cell memory population and viremia were analyzed in blood samples obtained from an occupational cohort in Guinea-Bissau, including HIV-2 viremic and aviremic individuals. For comparison, samples from HIV-1- or dually HIV-1/2-infected and seronegative individuals were obtained from the same cohort. CD8 T-cell exhaustion was evaluated by the combined expression patterns of activation, stimulatory and inhibitory immune checkpoint markers analyzed using multicolor flow cytometry and advanced bioinformatics. Unsupervised multidimensional clustering analysis identified a cluster of late differentiated CD8 T-cells expressing activation (CD38+, HLA-DRint/high), co-stimulatory (CD226+/-), and immune inhibitory (2B4+, PD-1high, TIGIThigh) markers that distinguished aviremic from viremic HIV-2, and treated from untreated HIV-1-infected individuals. This CD8 T-cell population displayed close correlations to CD4%, viremia, and plasma levels of IP-10, sCD14 and beta-2 microglobulin in HIV-2 infection. Detailed analysis revealed that aviremic HIV-2-infected individuals had higher frequencies of exhausted TIGIT+ CD8 T-cell populations lacking CD226, while reduced percentage of stimulation-receptive TIGIT-CD226+ CD8 T-cells, compared to seronegative individuals. Our results suggest that HIV-2 infection, independent of viremia, skews CD8 T-cells towards exhaustion and reduced co-stimulation readiness. Further knowledge on CD8 T-cell phenotypes might provide help in therapy monitoring and identification of immunotherapy targets.

HLA-E-restricted HIV-1-specific CD8+ T cell responses in natural infection.

CD8+ T cell responses restricted by MHC-E, a nonclassical MHC molecule, have been associated with protection in an SIV/rhesus macaque model. The biological relevance of HLA-E-restricted CD8+ T cell responses in HIV infection, however, remains unknown. In this study, CD8+ T cells responding to HIV-1 Gag peptides presented by HLA-E were analyzed. Using in vitro assays, we observed HLA-E-restricted T cell responses to what we believe to be a newly identified subdominant Gag-KL9 as well as a well-described immunodominant Gag-KF11 epitope in T cell lines derived from chronically HIV-infected patients and also primed from healthy donors. Blocking of the HLA-E/KF11 binding by the B7 signal peptide resulted in decreased CD8+ T cell responses. KF11 presented via HLA-E in HIV-infected cells was recognized by antigen-specific CD8+ T cells. Importantly, bulk CD8+ T cells obtained from HIV-infected individuals recognized infected cells via HLA-E presentation. Ex vivo analyses at the epitope level showed a higher responder frequency of HLA-E-restricted responses to KF11 compared with KL9. Taken together, our findings of HLA-E-restricted HIV-specific immune responses offer intriguing and possibly paradigm-shifting insights into factors that contribute to the immunodominance of CD8+ T cell responses in HIV infection.

STING Ligand-Mediated Priming of Functional CD8+ T Cells Specific for HIV-1-Protective Epitopes from Naive T Cells.

Functional HIV-1-specific CD8+ T cells primed from naive T cells are expected to act as effector T cells in a "shock-and-kill" therapeutic strategy for an HIV-1 cure since less functional HIV-1-specific CD8+ T cells are elicited from memory T cells in HIV-1-infected individuals on combined antiretroviral therapy (cART). CD8+ T cells specific for HIV-1 conserved and protective epitopes are candidates for such T cells. We investigated the priming with STING ligand of CD8+ T cells specific for HLA-B*52:01 or HLA-C*12:02-restricted protective epitopes from naive T cells. STING ligand 3'3'-cGAMP effectively primed CD8+ T cells specific for 3 of 4 HLA-B*52:01-restricted epitopes but failed to prime those specific for all 3 HLA-C*12:02-restricted epitopes from the naive T cells of HIV-1-uninfected individuals having an HLA-B*52:01-C*12:02 protective haplotype. These HLA-B*52:01-restricted CD8+ T cells had a strong ability to suppress HIV-1 replication and expressed a high level of cytolytic effector molecules. The viral suppression ability of these T cells was significantly correlated with the expression level of perforin and showed a trend for a positive correlation with the expression level of CD107a. The present study highlighted the priming with STING ligand of functional CD8+ T cells specific for protective epitopes, which T cells would contribute as effector T cells to a shock-and-kill therapy. IMPORTANCE The current "shock-and-kill" therapeutic strategy for HIV cure has been directed toward eliminating latent viral reservoirs by reactivation of latent reservoirs with latency-reversing agents followed by eradication of these cells by immune-mediated responses. Although HIV-1-specific T cells are expected to eradicate viral reservoirs, the function of these T cells is reduced in HIV-1-infected individuals with long-term cART. Therefore, priming of HIV-1-specific T cells with high function from naive T cells is to be expected in these individuals. In this study, we demonstrated the priming with STING ligand 3'3'-cGAMP of CD8+ T cells specific for HIV-1-protective epitopes from naive T cells. cGAMP primed CD8+ T cells specific for 3 HLA-B*52:01-restricted protective epitopes, which cells expressed a high level of cytolytic effector molecules and effectively suppressed HIV-1 replication. The present study suggested that the priming with STING ligand of functional CD8+ T cells specific for protective epitopes would be useful in a therapy for an HIV-1 cure.

Influence of NKG2C Genotypes on HIV Susceptibility and Viral Load Set Point.

NKG2C is an activating NK cell receptor encoded by a gene having an unexpressed deletion variant. Cytomegalovirus (CMV) infection expands a population of NKG2C+ NK cells with adaptive-like properties. Previous reports found that carriage of the deleted NKG2C- variant was more frequent in people living with HIV (PLWH) than in HIV- controls unexposed to HIV. The frequency of NKG2C+ NK cells positively correlated with HIV viral load (VL) in some studies and negatively correlated with VL in others. Here, we investigated the link between NKG2C genotype and HIV susceptibility and VL set point in PLWH. NKG2C genotyping was performed on 434 PLWH and 157 HIV-exposed seronegative (HESN) subjects. Comparison of the distributions of the three possible NKG2C genotypes in these populations revealed that the frequencies of NKG2C+/+ and NKG2C+/- carriers did not differ significantly between PLWH and HESN subjects, while that of NKG2C-/- carriers was higher in PLWH than in HESN subjects, in which none were found (P = 0.03, χ2 test). We were unable to replicate that carriage of at least 1 NKG2C- allele was more frequent in PLWH. Information on the pretreatment VL set point was available for 160 NKG2C+/+, 83 NKG2C+/-, and 6 NKG2C-/- PLWH. HIV VL set points were similar between NKG2C genotypes. The frequency of NKG2C+ CD3- CD14- CD19- CD56dim NK cells and the mean fluorescence intensity (MFI) of NKG2C expression on NK cells were higher on cells from CMV+ PLWH who carried 2, versus 1, NKG2C+ alleles. We observed no correlations between VL set point and either the frequency or the MFI of NKG2C expression. IMPORTANCE We compared NKG2C allele and genotype distributions in subjects who remained HIV uninfected despite multiple HIV exposures (HESN subjects) with those in the group PLWH. This allowed us to determine whether NKG2C genotype influenced susceptibility to HIV infection. The absence of the NKG2C-/- genotype among HESN subjects but not PLWH suggested that carriage of this genotype was associated with HIV susceptibility. We calculated the VL set point in a subset of 252 NKG2C-genotyped PLWH. We observed no between-group differences in the VL set point in carriers of the three possible NKG2C genotypes. No significant correlations were seen between the frequency or MFI of NKG2C expression on NK cells and VL set point in cytomegalovirus-coinfected PLWH. These findings suggested that adaptive NK cells played no role in establishing the in VL set point, a parameter that is a predictor of the rate of treatment-naive HIV disease progression.

Three-year mortality in cryptococcal meningitis: Hyperglycemia predict unfavorable outcome.

Existing evidence revealed grave prognosis for cryptococcal meningitis (CM), particularly its short-term mortality. However, its long-term survival and prognostic factors remained unknown. This study investigated 3-year mortality and analyzed its predictive factors in patients with CM. This retrospective cohort study with 83 cerebrospinal fluid culture-confirmed CM patients was conducted at China Medical University Hospital from 2003 to 2016. The 3-year mortality rate in patients with CM was 54% (45 deaths among 83 patients). Advanced age, human immunodeficiency virus (HIV) seronegative state, low Glasgow Coma Scale score on admission, decreased hemoglobin and hyperglycemia on diagnosis were associated with 3-year mortality. After multivariate adjustment in the Cox proportional hazard model, only severe hyperglycemia (serum glucose ≥200 mg/dL) on diagnosis could predict 3-year mortality.

The CH1α domain of mucosal gp41 IgA contributes to antibody specificity and antiviral functions in HIV-1 highly exposed Sero-Negative individuals.

The antibody molecule comprises a variable domain conferring antigen specificity and affinity distinct from the heavy chain constant (CH) domains dictating effector functions. We here interrogate this paradigm by evaluating the unique influence of the CH1α domain on epitope specificity and functions using two mucosal gp41-specific Fab-IgAs (FabA) derived from HIV-1 highly-exposed but persistently seronegative individuals (HESN). These HESN develop selectively affinity-matured HIV-1-specific mucosal IgA that target the gp41 viral envelope and might provide protection although by unclear mechanisms. Isotype-switching FabAs into Fab-IgGs (FabGs) results in a >10-fold loss in affinity for HIV-1 clade A, B, and C gp41, together with reduced neutralization of HIV-1 cross-clade. The FabA conformational epitopes map selectively on gp41 in 6-Helix bundle and pre-fusion conformations cross-clade, unlike FabGs. Finally, we designed in silico, a 12 amino-acid peptide recapitulating one FabA conformational epitope that inhibits the FabA binding to gp41 cross-clade and its neutralizing activity. Altogether, our results reveal that the CH1α domain shapes the antibody paratope through an allosteric effect, thereby strengthening the antibody specificity and functional activities. Further, they clarify the mechanisms by which these HESN IgAs might confer protection against HIV-1-sexual acquisition. The IgA-specific epitope we characterized by reverse vaccinology could help designing a mucosal HIV-1 vaccine.

Racial differences in α4ß7 expression on CD4+ T cells of HIV-negative men and women who inject drugs.

INTRODUCTION: We performed a cross-sectional study of HIV-uninfected men and women who inject drugs from the ALIVE cohort to examine if black men and women who inject drugs have higher levels of CD4+ T cells expressing the integrin heterodimer α4ß7 compared to white men and women. MATERIALS AND METHODS: Flow cytometry was used to examine expression of α4ß7 and other markers associated with different functional CD4+ T cell subsets in both men and women who inject drugs. RESULTS: Higher levels of α4ß7, CCR5, and CCR6 were observed on CD4+ T cells from black participants compared with white participants. In a multivariable model, α4ß7 expression differed by race, but not sex, age, or other factors. DISCUSSION: Black men and women express higher percentages of α4ß7 expressing CD4+ T cells, which may play a role in HIV disease.

Lípidos anormales e inmunidad adquirida Síndrome de Deficiencia: Asociación de Suero Lípidos con estatus de VIH / Abnormal Lipids and Acquired Immune Deficiency Syndrome: Association of Serum Lipids with HIV Status

Context and Aim: Hematological abnormalities are amongst the most common complications of infection with HIV.There have been quite a few studies on the alterations in lipid profile, too, though the results have largely been inconclusive. The present study was carried-out to assess CD4 cell counts and lipid profile in the HIV infected and AIDS patients in the Indian population and correlates them with the sero-negative controls. Materials and Methods: The present study was designed as a cross-sectional, hospital-based study to assess CD4 cell counts and lipid profile in the HIV infected and AIDS patients in the Indian population and correlates them with the sero-negative controls. Evaluation of lipid profile was done using Erba EM 360, an automated analyzer powered by a diffraction grating photometer while CD4 cell counts were evaluated using Partec Cyflow Counter. Statistical analysis used: The data was analyzed using SPSS version 15.0 (SPSS Inc., Chicago, IL, USA). Comparison of the said parameters was done using Analysis of Variance (ANOVA) and posthoc Games-Howell test. p-value of <0.05 was considered statistically significant. Results: The levels of total cholesterol and low-density lipoproteins (LDLs) were significantly decreased while triglycerides and very low density lipoproteins (VLDLs) were significantly increased in the HIV infected and AIDS patients when compared with the sero-negative controls. Conclusion: Total cholesterol, LDLs, triglycerides and VLDLs were significantly altered in the HIV infected and AIDS patients when compared with the sero-negative controls.

Genetic and epigenetic regulation of natural resistance to HIV-1 infection: new approaches to unveil the HESN secret.

Introduction: Since the identification of HIV, several studies reported the unusual case of small groups of subjects showing natural resistance to HIV infection. These subjects are referred to as HIV-1-exposed seronegative (HESN) individuals and include people located in different areas, with diverse ethnic backgrounds and routes of exposure. The mechanism/s responsible for protection from infection in HESN individuals are basically indefinite and most likely are multifactorial.Areas covered: Host factors, including genetic background as well as natural and acquired immunity, have all been associated with this phenomenon. Recently, epigenetic factors have been investigated as possible determinants of reduced susceptibility to HIV infection. With the advent of the OMICS era, the availability of techniques such as GWAS, RNAseq, and exome-sequencing in both bulk cell populations and single cells will likely lead to great strides in the understanding of the HESN mystery.Expert opinion: The employment of increasingly sophisticated techniques is allowing the gathering of enormous amounts of data. The integration of such information will provide important hints that could lead to the identification of viral and host correlates of protection against HIV infection, allowing the development of more effective preventative and therapeutic regimens.

IL-21 is associated with natural resistance to HIV-1 infection in a Colombian HIV exposed seronegative cohort.

Higher IL-21 levels were associated with natural resistance to HIV infection in an Italian cohort. Thus we wanted to confirm such association in HIV exposed seronegative individuals (HESN) from Colombia. Cells from HESN were less susceptible to infection and expressed higher IL-21 mRNA levels than healthy controls at both baseline and 7-days post-infection; similar results were observed for IL-6, perforin, and granzyme. These results suggest that IL-21/IL-6 increase may be a distinctive quality in the profile of HIV-1 resistance, at least during sexual exposure. However, further studies are necessary to confirm the specific protective mechanisms of these cytokines.

Cryptococcus neoformans seropositivity and some haematological parameters in HIV seropositive subjects.

BACKGROUND: Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningitis worldwide and may be fatal in immunocompromised subjects. In Nigeria, cases have been reported with prevalence between 4 and 13.1% in Human Immunodeficiency virus (HIV) patients depending on the study subjects. This study was designed to assess the prevalence of cryptococcosis, CD4+T cell counts and possible effect on haematological parameters in HIV seropositive subject in Nnewi, South-Eastern Nigeria. METHOD: A total of four hundred and twenty-nine (429) subjects were recruited for the study. Of these, two hundred and ninety (290) were HIV positive and one hundred and thirty-nine (139) were HIV seronegative subjects recruited from the voluntary counseling and testing (VCT) unit and HIV care clinic at Nnamdi Azikiwe University Teaching Hospital Nnewi, Anambra State, Nigeria. Their ages were between 18-80 years. One hundred and thirty nine (139) apparently healthy HIV seronegative subjects were recruited as controls. Blood samples were taken for C. neoformans by Antigen lateral flow assay (CrAgLFA), HIV testing, CD4+T cell, platelet and Full blood count (FBC). RESULTS: Our results show that of the two hundred and ninety (290) who were HIV positive subjects investigated for cryptococcosis, 4 (1.4%) tested positive for CrAg of whom 1(25%) were male and 3(75%) were female. All those with cryptococcosis had their CD4 count below 200 cells/µL, three of them were on ART and one was not. There were significant differences in the CD4 counts (P<0.05) between those infected and not infected with C. neoformans. None of the control group tested positive to cryptococcosis. CONCLUSION: Widespread use of anti-retroviral therapy may have reduced C. neoformans infection. However, the threat remains and there may be a possibility that women may be a more vulnerable population.

Lower prevalence of Blastocystis sp. infections in HIV positive compared to HIV negative adults in Ghana.

BACKGROUND: Sub-Saharan Africa is endemic for intestinal parasites and distinguished for the largest burden of HIV cases. Blastocystis sp. is one of the most common protists infecting humans but its role in human disease is still controversial. Aim of this study was to investigate the prevalence of Blastocystis sp. in HIV positive and negative adults in Ghana and its association with immune status and other risk factors. METHODS: 122 HIV positive outpatients and 70 HIV negative blood donors from the Komfo Anokye Teaching Hospital in Kumasi, Ghana, were included in the present study. Demographic, clinical and laboratory data were collected and HIV positive patients distinguished for CD4+ T cell count <200 cells/µl (n = 54) and >200 cells/µl (n = 68). A Blastocystis's phylogenetic analysis was performed to determine sample subtype (ST). RESULTS: The prevalence of Blastocystis sp. in adult HIV positive individuals was lower than in HIV negative persons (6.6% vs. 20.0%, p = 0.008) and Blastocystis sp. ST1 was the most prevalent strain. Within HIV positive participants, the prevalence of Blastocystis sp. was lower in those individuals with CD4+ T cell count <200 cells/µl than in patients with higher CD4+ T cell count (1.9% vs. 10.3%, p = 0.076). Multiple regression analysis revealed that Blastocystis sp. was inversely associated with an obese Body Mass Index (BMI) in HIV negative persons (p = 0.040). Presence of Blastocystis sp. was correlated with higher CD4+ T cell count in HIV positive participants (p = 0.049). CONCLUSION: It is largely reported that people living with HIV (PLHIV) in Africa are affected from parasite infections and that co-infections may adversely impact on their immune status, accelerating progress to AIDS and worsening gastrointestinal manifestations. Differently, in this study Blastocystis sp. was associated with a better immune status jointly with a healthy body weight while it seems to be reduced with the progression of HIV infection. This data agree with recent suggestions that Blastocystis sp. can represent a component of the healthy gut microbiota.

Short Communication: Extremely Severe CD4 Lymphopenia During HIV-1 Primary Infection.

We report the case of a patient with a very profound CD4 T cell lymphopenia <20 cells/mm3 in the context of a primary HIV-1 infection, associated with both delayed HIV-specific antibody and CD8 T cell responses. A long-term immune reconstitution was observed after immediate initiation of antiretroviral therapy.

Induction of Follicular-Like CXCR5+ CD8+ T Cells by TGF-ß1/IL-23 Is Limited During HIV Infection.

Follicular CD4+ T cells are the main HIV reservoirs due to, among other factors, the low frequency of CD8+ T cells in lymphoid follicles. Follicular CXCR5+ CD8+ T cells are associated with HIV control, but their differentiation conditions are yet undefined. In this study, we explored the in vitro effect of transforming growth factor (TGF)-ß1, interleukin (IL)-12, and IL-23 on the induction of CXCR5, the follicle homing receptor, in human circulating CD8+ T cells from seronegative, and treated HIV-infected individuals. The combination of TGF-ß1 plus IL-23 induced the highest expression of CXCR5 in purified CD8+ T cells. These CXCR5+ CD8+ T cells also expressed a transcriptional and phenotypic profile similar to that of follicular CD4+ T cells, such as the upregulation of BCL6, inducible costimulator and CD40L, and downregulation of PRDM1. These cells responded in vitro to CXCL13 and had low expression of CCR7. In addition, after polyclonal stimulation, they produced IL-21, interferon-γ, and de novo perforin. However, in comparison with seronegative individuals, CD8+ T cells from HIV-infected patients had a lower response to TGF-ß1/IL-23, a defect that was restored with the blockade of the programmed cell death 1 inhibitory receptor. Thus, TGF-ß1 plus IL-23 induce follicular-like CXCR5+ CD8+ T cells in seronegative individuals, but in HIV-infected patients there is a limited response which could impair the generation of this cell population.

Gastrointestinal Parasitic Infections and Immunological Status of HIV/AIDS Coinfected Individuals in Nigeria.

BACKGROUND: Parasitic infections of the gastrointestinal tract is one of the highest causes of morbidity and mortality among HIV infected individuals. This is due to the colonization of the intestinal tract by parasites influenced by induced enteropathy caused by HIV infection. CD+4 t-lymphocytes count is a marker of the immune status of HIV infected individuals. OBJECTIVE: This study investigated the prevalence of gastrointestinal parasitic infections among HIV coinfected individuals in relation to their immunological status. METHODS: CD+4 t-lymphocytes count was determined using fluorescence-activated cell sorting (FACS) count system. Parasitological examination of faecal samples was conducted using direct wet mount, modified Z-N and Giemsa stain techniques. All prepared slides were examined under x10 and x40 objectives. FINDINGS: Out of the 891 HIV seropositive participants on antiretroviral therapy that were studied, 641 (71.9%) had CD+4 counts equals to or greater than 500 cells/mm3. All other seropositive participants had CD+4 counts below 500 cells/mm3. Gastrointestinal parasitic infections were recorded in 187 (20.9%) seropositive participants, with females (n = 108, 12.1%) having more infections than males. Multiple gastrointestinal parasitic infections were recorded in 28 (3.1%) seropositive participants. Out of the 150 seronegative participants, 79 (52.7%) of them had at least one gastrointestinal parasitic infection. Female seronegative participants also accounted for higher infection rate (n = 42, 28.0%) than males (n = 37, 24.7%). Multiple infections were also recorded in 18 (12.0%) seronegative individuals. The overall prevalence rate of infection between both positive and negative individuals was 25.5%. There was statistical significant difference in the infections of Cryptosporidium parvum (p < 0.003), Cyclospora cayetanensis (p < 0.011) and Cystoisospora belli (p < 0.011) between HIV seropositive and HIV seronegative individuals. Also, there was statistical significant difference in the infections of hook worm (p < 0.002) and Trichuris trichiura (p < 0.020) between seronegative and seropositive individuals. Gastrointestinal parasitic infection rate was significantly higher among seropositive participants with CD+4 counts between 200 and 350 cells/mm3 (n = 109, 58.3%). CONCLUSION: The study shows that HIV infected individuals continue to experience gastrointestinal infections even with antiretroviral treatment, especially those with CD+4 counts below 350 cells/mm3. Health care providers should prioritise routine screening of HIV patients for gastrointestinal parasites and provide prompt treatment. Antiparasitic drugs should also be provided as prophylaxis.

Natural Immunity to HIV is associated with Low BLyS/BAFF levels and low frequencies of innate marginal zone like CD1c+ B-cells in the genital tract.

BLyS/BAFF is recognized for its role in B-cell ontogenesis, as well as cell fate decision towards the first-line/innate marginal zone (MZ) B-cell pool. Excess BLyS/BAFF is associated with hyperglobulinemia and increased frequencies of activated precursor-like MZ B-cells. Herein, we show that HIV highly-exposed seronegative (HESN) commercial sex workers (CSWs) had lower soluble BLyS/BAFF levels and relative frequencies of BLyS/BAFF expressing cells in their genital mucosa when compared to those from HIV-infected CSWs and HIV-uninfected non-CSWs. Furthermore, we identified genital innate and/or marginal zone (MZ)-like CD1c+ B-cells that naturally bind to fully glycosylated gp120, which frequencies were lower in HESNs when compared to HIV-infected CSWs and HIV-uninfected non-CSWs. Although genital levels of total IgA were similar between groups, HESNs had lower levels of total IgG1 and IgG3. Interestingly, HIV-gp41 reactive IgG1 were found in some HESNs. Low genital levels of BLyS/BAFF observed in HESNs may allow for controlled first-line responses, contributing to natural immunity to HIV.

Endothelial Colony-Forming Cell Function Is Reduced During HIV Infection.

BACKGROUND: Human immunodeficiency virus (HIV) may be related to cardiovascular disease through monocyte activation-associated endothelial dysfunction. METHODS: Blood samples from 15 HIV-negative participants (the uninfected group), 8 HIV-positive participants who were not receiving antiretroviral therapy (ART) (the infected, untreated group), and 15 HIV-positive participants who were receiving ART (the infected, treated group) underwent flow cytometry of endothelial colony-forming cells (ECFCs) and monocyte proportions. IncuCyte live cell imaging of 8 capillary proliferative capacity parameters were obtained from cord blood ECFCs treated with participant plasma. RESULTS: The ECFC percentage determined by flow cytometry was not different between the study groups; however, values of the majority of capillary proliferative capacity parameters (ie, cell area, network length, network branch points, number of networks, and average tube width uniformity) were significantly lower in infected, untreated participants as compared to values for uninfected participants or infected, treated participants (P < .00625 for all comparisons). CD14+CD16+ intermediate monocytes and soluble CD163 were significantly and negatively correlated with several plasma-treated, cord blood ECFC proliferative capacity parameters in the combined HIV-positive groups but not in the uninfected group. CONCLUSIONS: Cord blood ECFC proliferative capacity was significantly impaired by plasma from infected, untreated patients, compared with plasma from uninfected participants and from infected, treated participants. Several ECFC functional parameters were adversely associated with monocyte activation in the HIV-positive groups, thereby suggesting a mechanism by which HIV-related inflammation may impair vascular reparative potential and consequently increase the risk of cardiovascular disease during HIV infection.

S100A14 Is Increased in Activated NK Cells and Plasma of HIV-Exposed Seronegative People Who Inject Drugs and Promotes Monocyte-NK Crosstalk.

BACKGROUND: HIV-exposed seronegative people who inject drugs (HESN-PWID) have been shown to have increased natural killer (NK) cell and myeloid activation when compared with control donors. METHODS: We investigated potential mechanisms maintaining NK activation by conducting quantitative proteome comparisons of NK cells from HESN-PWID subjects and control donors. Proteins upregulated in NK cells were measured in the plasma of HESN-PWID subjects by ELISA and further investigated for their ability to induce innate immune activation in vitro. RESULTS: The NK cell proteome comparison showed markedly higher levels of interferon-stimulated proteins and S100 proteins, including S100A14. Consistent with these results, we observed significantly higher levels of S100A14 in the plasma of HESN-PWID subjects compared with controls (P = 0.033, n = 25). In vitro, the addition of recombinant S100A14 protein significantly activated NK cells in a peripheral blood mononuclear cell mixture (P = 0.011, n = 9), but not purified NK cells alone. Treatment of purified monocytes with recombinant S100A14 protein induced secretion of TNF-alpha and led to significantly higher NK CD69 activation (P = 0.0156, n = 7) in a co-culture through a TLR4-dependent interaction. CONCLUSIONS: Our study identified S100A14 as a novel protein increased within NK cells and plasma of HESN-PWID subjects with the capacity to sustain NK activation through TLR4-dependent activation of myeloid cells.

Low T-cell subsets prior to development of virus-associated cancer in HIV-seronegative men who have sex with men.

Immunological parameters that influence susceptibility to virus-associated cancers in HIV-seronegative individuals are unclear. We conducted a case-control cohort study of immunological parameters associated with development of incident virus-associated cancers among 532 HIV-seronegative men who have sex with men (MSM) enrolled in the Multicenter AIDS Cohort Study (MACS) with median (IQR) 21 (8-26) years of follow-up. Thirty-two incident virus-associated cancers (anal cancer, non-Hodgkin lymphoma, liver cancer, other cancers with etiologies linked to human papillomavirus, Epstein-Barr virus, hepatitis B virus, or human herpesvirus-8) were identified among 3,408 HIV-seronegative men in the MACS during 1984-2010. Cases were matched for demographics, smoking, and follow-up to 500 controls without cancer. Mixed-effects and Cox regression models were used to examine associations between nadir or recent CD4, CD8, and white blood cell (WBC) counts or CD4:CD8 ratios and subsequent diagnosis of virus-associated cancers. Men with incident virus-associated cancers had lower CD4 and WBC counts over a 6-year window prior to diagnosis compared to men without cancer (p = 0.001 and 0.03, respectively). Low CD4 cell count and nadir, CD4 count-nadir differential, and CD4:CD8 ratio nadir were associated with increased 2-year risk of incident virus-associated cancers in models adjusted for demographics and smoking (hazard ratios 1.2-1.3 per 100 or 0.1 unit decrease, respectively; p < 0.01). Other associated factors included heavy smoking and past or current hepatitis B virus infection. These findings show that low CD4 cell counts, CD4 nadir, and CD4:CD8 cell ratios are independent predictors for subsequent risk of virus-associated cancers in HIV-seronegative MSM.