Effects of Early and Delayed Antiretroviral Therapy on Plasma Anti-CD4 Autoreactive IgG and Its Association With CD4+ T-Cell Recovery in Acute HIV-Infected Individuals

Impacts of plasma microbial lipopolysaccharide translocation on B cell perturbations and anti-CD4 autoantibody production in people with HIV on suppressive antiretroviral therapy

BACKGROUND

. Up to 20% of people with HIV (PWH) who undergo virologically suppressed antiretroviral therapy (ART) fail to experience complete immune restoration. We recently reported that plasma anti-CD4 IgG (antiCD4IgG) autoantibodies from immune non-responders specifically deplete CD4 + T cells via antibody-dependent cytotoxicity. However, the mechanism of antiCD4IgG production remains unclear.

METHODS

. Blood samples were collected from 16 healthy individuals and 25 PWH on suppressive ART. IgG subclass, plasma lipopolysaccharide (LPS), and antiCD4IgG levels were measured by ELISA. Gene profiles in B cells were analyzed by microarray and quantitative PCR. Furthermore, a patient-derived antiCD4IgG-producing B cell line was generated and stimulated with LPS in vitro. B cell IgG class switch recombination (CSR) was evaluated in response to LPS in splenic B cells from C57/B6 mice in vitro.

RESULTS

. Increased plasma anti-CD4 IgGs in PWH were predominantly IgG1 and associated with increased plasma LPS levels as well as B cell expression of TLR2, TLR4, and MyD88 mRNA in vivo. Furthermore, LPS stimulation induced antiCD4IgG production in the antiCD4IgG B cell line in vitro. Finally, LPS promoted CSR in vitro.

CONCLUSION

. Our findings suggest that persistent LPS translocation may promote anti-CD4 autoreactive B cell activation and antiCD4IgG production in PWH on ART, which may contribute to gradual CD4 + T cell depletion. This study suggests that reversing a compromised mucosal barrier could improve ART outcomes in PWH who fail to experience complete immune restoration.

Infectious diseases, autoantibodies, and autoimmunity

Infections are known to trigger flares of autoimmune diseases in humans and serve as an inciting cause of autoimmunity in animals. Evidence suggests a causative role of infections in triggering antigen-specific autoimmunity, previous thought mainly through antigen mimicry. However, an infection can induce bystander autoreactive T and B cell polyclonal activation, believed to result in non-pathogenic and pathogenic autoimmune responses. Lastly, epitope spreading in autoimmunity is a mechanism of epitope changes of autoreactive cells induced by infection, promoting the targeting of additional self-epitopes. This review highlights recent research findings, emphasizes infection-mediated autoimmune responses, and discusses the possible mechanisms involved.

Persistent T cell proliferation and MDSCs expansion precede incomplete CD4+ T cell recovery in people with acute HIV-1 infection with early ART

HIV-1 infection causes T cell dysfunction that cannot be fully restored by anti-retroviral therapy (ART). Myeloid-derived suppressor cells (MDSCs) expand and suppress T cell function during viral infection. In this study, we evaluated the dynamics of phenotypes and function of T cells and MDSCs and the effects of their interaction on CD4⁺ T cell reconstitution in people with acute HIV-1 infection (PWAH) with early ART. Flow cytometry was used to detect the phenotypic dynamics and function of T cells and MDSCs at pre-ART, 4, 24, 48, and 96 weeks of ART. We observed that T cells were hyper-activated and hyper-proliferative in PWAH at pre-ART. Early ART normalized T cell activation but not their proliferation. T cell proliferation, enriched in PD-1⁺ T cells, was persisted and negatively associated with CD4⁺ T-cell counts after ART. Moreover, M-MDSCs frequency was increased and positively correlated with T cell proliferation after 96 weeks of ART. M-MDSCs persisted and inhibited T cell proliferation ex vivo, which could be partially reversed by PD-L1 blockade. Further, we found higher frequencies of proliferative CD4⁺ T cells and M-MDSCs in PWAH with lower CD4⁺ T cell numbers (<500 cells/μL) compared to PWAH with higher CD4⁺ T cell numbers (>600 cells/μL) after 96 weeks of ART. Our findings indicate that persistent T cell proliferation, MDSCs expansion, and their interaction may affect CD4⁺ T-cell recovery in PWAH with early ART.

Evaluation of Clinical Biomarkers Related to CD4 Recovery in HIV-Infected Patients—5-Year Observation

Human Immunodeficiency Virus infection leads to the impairment of immune system function. Even long-term antiretroviral therapy uncommonly leads to the normalization of CD4 count and CD4:CD8 ratio. The aim of this study was to evaluate possible clinical biomarkers which may be related to CD4 and CD4:CD8 ratio recovery among HIV-infected patients with long-term antiretroviral therapy. The study included 68 HIV-infected patients undergoing sustained antiretroviral treatment for a minimum of 5 years. Clinical biomarkers such as age, gender, advancement of HIV infection, coinfections, comorbidities and applied ART regimens were analyzed in relation to the rates of CD4 and CD4:CD8 increase and normalization rates. The results showed that higher rates of CD4 normalization are associated with younger age (p = 0.034), higher CD4 count (p = 0.034) and starting the therapy during acute HIV infection (p = 0.012). Higher rates of CD4:CD8 ratio normalization are correlated with higher CD4 cell count (p = 0.022), high HIV viral load (p = 0.006) and acute HIV infection (p = 0.013). We did not observe statistically significant differences in CD4 recovery depending on gender, HCV/HBV coinfections, comorbidities and opportunistic infections. The obtained results advocate for current recommendations of introducing antiretroviral therapy as soon as possible, preferably during acute HIV infection, since it increases the chances of sufficient immune reconstruction.

Anti-CD4 autoantibodies in immunological non-responder people living with HIV: Cause of CD4+ T-cell depletion?

OBJECTIVE

We aimed to evaluate the anti-CD4 IgG role in the poor immune recovery of immunological nonresponder people with HIV (INR).

DESIGN

INR display low CD4+ T-cell increase despite long-term undetectable viremia. Among other factors, autologous anti-CD4 IgG-dependent cellular cytotoxicity (ADCC) by natural killer (NK) cells has been proposed to cause CD4+ T-cell depletion.

METHODS

Plasma anti-CD4 IgG levels were quantified and purified by chromatography columns for the subsequent use in a coculture of CD4+ T and NK cells. We analyzed NK cell degranulation markers (CD107a, perforin and granzyme B) and IFN-γ release, and CD4+ T-cell death. Binding affinity of anti-CD4 IgG for CD4+ T cells was also assessed.

RESULTS

A total of 168 individuals were enrolled (INR, 56; immunological responders, 40; treatment-naive, 39; and healthy controls, 33). The highest anti-CD4 IgG levels were found in treatment-naive PWH, followed by participants on treatment. There were no correlations between anti-CD4 IgG levels and CD4+ T-cell counts. In a 15-participant subgroup (naive, immunological responders, and INR), anti-CD4 IgG induced a slight NK-cell expression of degranulation markers and IFN-γ; however, the percentage of CD4+ T-cell death was negligible. Consistently, no significant changes in NK cell polyfunctionality were observed. In addition, purified anti-CD4 IgG showed scarce binding affinity for CD4+ T cells. These results were similar in all analyzed participant groups.

CONCLUSION

Our results suggest that autologous anti-CD4 IgG neither trigger CD4+ T-cell death by ADCC nor are responsible for CD4+ lymphocyte depletion in INR.

VIDEO ABSTRACT

http://links.lww.com/QAD/C518.

Abnormal Shift in B Memory Cell Profile Is Associated With the Expansion of Circulating T Follicular Helper Cells via ICOS Signaling During Acute HIV-1 Infection

Interactions between T follicular helper (Tfh) cells and germinal center B cells are essential for the differentiation of B cells and specific antibody responses against HIV-1 infection. However, the extent to which HIV-1 infection affects the dynamic interplay between these two cell populations in the bloodstream remains unclear. In this study, the dynamics of circulating Tfh (cTfh) and B cells and their relationship in individuals with acute and chronic HIV-1 infection were investigated. Twenty-five study subjects were enrolled from the Beijing PRIMO clinical cohort, a prospective cohort of HIV-1-negative men who have sex with men (MSM) for the identification of cases of acute HIV-1 infection (AHI) at Beijing Youan Hospital, Capital Medical University. Individuals with AHI were selected at random. Matched samples were also collected and analyzed from the same patients with chronic HIV-1 infection. None of the study subjects received antiretroviral therapy during acute or chronic infection. Multicolor flow cytometry was used for the immunophenotypic and functional characterization of cTfh cell and B cell subsets. AHI resulted in increased proportions in bulk cTfh, ICOS⁺cTfh or IL-21⁺ICOS⁺cTfh cells. In both acute and chronic infections, activated memory (AM), tissue-like memory (TLM), and plasmablast (PB) B cell levels were increased whilst resting memory (RM) and naïve mature (NM) B cell levels were decreased. Classical memory (CM) B cells were unaffected during infection. Association analyses showed that the levels of ICOS⁺cTfh and IL-21⁺ICOS⁺cTfh cells were negatively correlated with those of AM, CM, RM cells, and positively correlated with those of NM cells in AHI but not chronic HIV-1 infection stage (CHI). Moreover, the frequency of IL-21⁺ICOS⁺cTfh cells was also positively correlated with plasma HIV-1 viral load, and had an opposite association trend with CD4⁺T cell count in AHI. Our data suggests that HIV-1 infection drives the expansion of cTfh cells, which in turn leads to perturbations of B cell differentiation through ICOS signaling during acute infection stage. These findings provide insight on the role of ICOS in the regulation of cTfh/B cell interaction during AHI and may potentially guide the design of effective strategies for restoring anti-HIV-1 immunity in the infected patients.

The impact of regional socioeconomic deprivation on the timing of HIV diagnosis: a cross-sectional study in Germany

BACKGROUND

HIV infections which are diagnosed at advanced stages are associated with significantly poorer health outcomes. In Germany, the proportion of persons living with HIV who are diagnosed at later stages has remained continuously high. This study examined the impact of regional socioeconomic deprivation on the timing of HIV diagnosis.

METHODS

We used data from the national statutory notification of newly diagnosed HIV infections between 2011 and 2018 with further information on the timing of diagnosis determined by the BED-Capture-ELISA test (BED-CEIA) and diagnosing physicians. Data on regional socioeconomic deprivation were derived from the German Index of Socioeconomic Deprivation (GISD). Outcome measures were a non-recent infection based on the BED-CEIA result or an infection at the stage of AIDS. The effect of socioeconomic deprivation on the timing of diagnosis was analysed using multivariable Poisson regression models with cluster-robust error variance.

RESULTS

Overall, 67.5% (n = 10,810) of the persons were diagnosed with a non-recent infection and 15.2% (n = 2746) with AIDS. The proportions were higher among persons with heterosexual contact compared to men who have sex with men (MSM) (76.8% non-recent and 14.9% AIDS vs. 61.7% non-recent and 11.4% AIDS). MSM living in highly deprived regions in the countryside (< 100 k residents) were more likely to have a non-recent infection (aPR: 1.16, 95% CI: 1.05-1.28) as well as AIDS (aPR: 1.41, 95% CI: 1.08-1.85) at the time of diagnosis compared to MSM in less deprived regions in the countryside. No differences were observed among MSM from towns (100 k ≤ 1 million residents) or major cities (≥ 1 million residents), and no differences overall in the heterosexual transmission group.

CONCLUSIONS

An effect of socioeconomic deprivation on the timing of HIV diagnosis was found only in MSM from countryside regions. We suggest that efforts in promoting HIV awareness and regular HIV testing are increased for heterosexual persons irrespective of socioeconomic background, and for MSM with a focus on those living in deprived regions in the countryside.

Elevated Cerebrospinal Fluid Anti-CD4 Autoantibody Levels in HIV Associate with Neuroinflammation

The mechanisms of persistent central nervous system (CNS) inflammation in people with HIV (PWH) despite effective antiretroviral therapy (ART) are not fully understood. We have recently shown that plasma anti-CD4 IgGs contribute to poor CD4⁺ T cell recovery during suppressive ART via antibody-mediated cytotoxicity (ADCC) against CD4⁺ T cells, and that plasma anti-CD4 IgG levels are associated with worse cognitive performance and specific brain area atrophy. However, the role of anti-CD4 IgGs in neuroinflammation remains unclear. In the current study, plasma and cerebrospinal fluid (CSF) samples from 31 ART-naive and 26 treated, virologically suppressed PWH, along with 16 HIV-seronegative controls, were evaluated for CSF levels of anti-CD4 IgG, white blood cell (WBC) counts, soluble biomarkers of neuroinflammation, and neurofilament light chain (NfL). We found that 37% of the PWH exhibited elevated CSF anti-CD4 IgG levels, but few or none of the PWH were observed with elevated CSF anti-CD4 IgM, anti-CD8 IgG, or anti-double-strand DNA IgG. CSF anti-CD4 IgG levels in PWH were directly correlated with neuroinflammation (WBC counts, neopterin, and markers of myeloid cell activation), but not with CSF NfL levels. Using cells from one immune nonresponder to ART, we generated a pathogenic anti-CD4 monoclonal IgG (JF19) presenting with ADCC activity; JF19 induced the production of soluble CD14 (sCD14) and interleukin-8 (IL-8) in human primary monocyte-derived macrophages via CD4 binding in vitro. This study demonstrates for the first time that elevated CSF anti-CD4 IgG levels present in a subgroup of PWH which may play a role in neuroinflammation in HIV.

IMPORTANCE This study reports that an autoantibody presents in the CNS of HIV patients and that its levels in the CSF correlate with some markers of neuroinflammation.

Predictors of attrition among adults in a rural HIV clinic in southern Mozambique: 18-year retrospective study

HIV remains a major cause of morbidity and mortality for people living in many low-income countries. With an HIV prevalence of 12.4% among people aged over 15 years, Mozambique was ranked in 2019 as one of eight countries with the highest HIV rates in the world. We analyzed routinely collected data from electronical medical records in HIV-infected patients aged 15 years or older and enrolled at Carmelo Hospital of Chokwe in Chokwe from 2002 to 2019. Attrition was defined as individuals who were either reported dead or lost to follow-up (LTFU) (≥ 90 days since the last clinic visit with missed medical pick-up after 3 days of failed calls). Kaplan–Meier survival curves and Cox regression analyses were used to model the incidence and predictors of time to attrition. From January 2002 to December 2019, 16,321 patients were enrolled on antiretroviral therapy (ART): 59.2% were women, and 37.9% were aged 25–34 years old. At the time of the analysis, 7279 (44.6%) were active and on ART. Overall, the 16,321 adults on ART contributed a total of 72,987 person-years of observation. The overall attrition rate was 9.46 per 100 person-years. Cox regression showed a higher risk of attrition in those following an inpatient regimen (hazard ratio [HR] 3.18, 95% confidence interval [CI] 2.89–3.50; p < 0.001), having CD4 counts under 50 cells/µL (HR 1.91, 95% CI 1.63–2.24, p < 0.001), receiving anti-TB treatment within 90 days of ART initiation (HR 6.53, 95% CI 5.72–7.45; p < 0.001), classified as WHO clinical stage III (HR 3.75, 95% CI 3.21–4.37; p < 0.001), and having Kaposi’s sarcoma (HR 1.99, 95% CI 1.65–2.39, p < 0.001). Kaplan–Meier analysis showed that patients with CD4 counts of less than 50 cells/µL on ART initiation had a 40% lower chance of survival at 18 years. Low CD4 cell counts, ART initiation as an inpatient, WHO clinical stage III, and anti-tuberculosis treatment within 90 days of ART initiation were strongly associated with attrition. Strengthening HIV testing and ART treatment, improving the diagnosis of tuberculosis before ART initiation, and guaranteed psychosocial support systems are the best tools to reduce patient attrition after starting ART.

Demographic and clinical factors associated with immune reconstitution in HIV/HBV co-infected and HIV mono-infected patients: a retrospective cohort study

OBJECTIVES

To describe the clinical characteristics and factors associated with CD4 T-cell count and CD4/CD8 ratio restoration in HIV mono-infected and HIV/HBV co-infected individuals, and to explore liver and renal functional changes in both groups.

METHODS

A retrospective cohort study was performed including 356 HIV/HBV co-infected and 716 HIV mono-infected participants who initiated antiretroviral therapy (ART) during 2013-2017 in Beijing Youan Hospital, China. Demographic and clinical characteristics were compared between the two groups, using χ² and Mann-Whitney non-parametric tests. Bivariate and multivariate Cox regression models were used to test their association.

RESULTS

Baseline HIV viral load and ART regimen were found to be significantly associated with CD4 T-cell restoration among HIV-infected participants, whereas baseline HIV viral load was the only significant factor associated with CD4 T-cell restoration in HIV/HBV co-infected participants. The final model showed that baseline HIV viral load and ART regimen were significantly associated with CD4/CD8 ratio restoration among HIV-infected participants, while baseline HIV viral load was the significant factor. Liver and renal functions were similar at the endpoint (P > 0.05).

CONCLUSIONS

Baseline HIV viral load count was found to be the key factor affecting immune restoration in both HIV and HIV/HBV individuals. Future multi-wave prospective studies are needed to clarify the potential biological mechanism.