Nadia Alatrakchi

The Effect of Raltegravir Intensification on Low-level Residual Viremia in HIV-Infected Patients on Antiretroviral Therapy: A Randomized Controlled Trial

In a double-blind trial, Rajesh Gandhi and colleagues detect no significant reduction in viral load after people with low-level HIV viremia added an integrase inhibitor to their treatment regimen.

Hepatitis C virus (HCV)-specific CD8+ cells produce transforming growth factor beta that can suppress HCV-specific T-cell responses.

ABSTRACT Hepatitis C virus (HCV)-specific T-cell responses are rarely detected in peripheral blood, especially in the presence of human immunodeficiency virus (HIV) coinfection. Based on recent evidence that T-regulatory cells may be increased in chronic HCV, we hypothesized that functional blockade of regulatory cells could raise HCV-specific responses and might be differentially regulated in the setting of HIV coinfection. Three groups of subjects were studied: HCV monoinfected, HCV-HIV coinfected, and healthy controls. Frequencies of peripheral T cells specific for peptides derived from HCV core, HIV type 1 p24, and recall antigens were analyzed by gamma interferon (IFN-γ) enzyme-linked immunospot assay. HCV-specific T-cell responses were very weak in groups with HCV and HCV-HIV infections. Addition of blocking antibodies against transforming growth factor β1 (TGF-β1), -2, and -3 and interleukin-10 specifically increased the HCV-specific T-cell responses in both infected groups; however, this increase was attenuated in the group with HCV-HIV coinfection compared to HCV infection alone. No increase in recall antigen- or HIV-specific responses was observed. Flow cytometric sorter analysis demonstrated that regulatory-associated cytokines were produced by HCV-specific CD3+CD8+CD25− cells. Enhancement of the IFN-γ effect was observed for both CD4 and CD8 T cells and was mediated primarily by TGF-β1, -2, and -3 neutralization. In conclusion, blockade of TGF-β secretion could enhance peripheral HCV-specific T-cell responses even in the presence of HIV coinfection.

Regulatory T cells and viral liver disease

Summary.  Important questions remain on the role of T cells in progression of hepatitis virus‐mediated liver pathogenesis: are T cells ‘Good or Bad’? How could one maintain a beneficial balance, in which regulatory T‐cell (Treg) populations might play an important role? Treg are a heterogeneous population of cells, including the classical CD4+CD25+ subset expressing the transcription factor Foxp3, CD4 T cells secreting IL‐10 (Tr1) or TGF‐β (Th3), but also some CD8 T cells, double negative T cells and γδ T cells. The role of Treg in viral hepatitis, particularly HBV and HCV, seems to range from suppressing T‐cell responses directed against hepatitis viruses to down‐regulating the immune responses causing the liver damage. Questions also remain unresolved on which Treg populations are important and how to establish a beneficial balance, mostly due to the difficulties in studying the heterogeneous Treg populations but also due to the problem accessing liver, the principal target of hepatitis viruses. Here, we will review progress to date on understanding Treg populations in regard to viral hepatitis.

Persistent low viral load on antiretroviral therapy is associated with T cell-mediated control of HIV replication.

Background:It is unclear how stable low-level viral replication and CD4 cell numbers can be maintained under highly active antiretroviral therapy (HAART). This study was designed to analyse whether HIV-specific responses in stable partially controlled patients during antiretroviral therapy (ART) differ from those observed in complete HAART failure and whether they contribute to the control of viral load (VL). Methods:Three groups of patients were selected according to plasma HIV RNA levels during 18 months of ART: persistently low VL (LoVL; HIV RNA <10 000 copies/ml; n = 28), undetectable VL (UnVL; HIV RNA <200 copies/ml; n = 29) and high VL (HiVL; HIV RNA >10 000 copies/ml; n = 14). T-cell responses were studied using lymphoproliferative and interferon (IFN)-γ-ELISpot assays against HIV-p24, -gp160, recall antigens, and 15 pools of HIV-(Gag + RT) peptides. Results:Frequencies of IFN-γ-producing CD4 T cells against HIV-p24 were higher in LoVL than in UnVL or HiVL groups [median, 131, 47 and 23 spot-forming cells (SFC)/1 × 106 peripheral blood mononuclear cells (PBMC), respectively; P = 0.012 and P = 0.047]. Lymphoproliferative responses to HIV-p24 and recall antigens were similar in LoVL and UnVL groups but lower in HiVL (P = 0.004). Frequencies of HIV-specific CD8 T cells were higher in LoVL than in UnVL (1340 versus 410 SFC/1 × 106 PBMC; P = 0.001). They correlated negatively with VL in the LoVL and HiVL (r, −0.393, P = 0.039 and r, −0.643, P = 0.024, respectively) and positively correlated with anti-HIV CD4 cell frequencies in the LoVL group only (r, 0.420; P = 0.026). Conclusion:Persistently low viral replication (<10 000 copies/ml) during ART stimulates high frequencies of HIV-specific CD4 and CD8 T cells compared to full virus suppression or complete ART failure. The association of high anti-HIV activity with large numbers of HIV-specific CD8 T cells contribute to the control of viral replication.

CD8+ Cell Responses to Hepatitis C Virus (HCV) in the Liver of Persons with HCV-HIV Coinfection versus HCV Monoinfection

OBJECTIVE Cellular immune responses are difficult to detect in the peripheral blood of persons with chronic hepatitis C virus (HCV) infection. We sought to determine whether T cell responses were present in the liver of patients with human immunodeficiency virus (HIV) and HCV coinfection. METHODS T cells were expanded from liver-biopsy samples from 10 patients coinfected with HIV and HCV (median CD4(+) cell count, 456 cells/mm(3)) and 8 patients infected with HCV alone. CD8(+) cell responses were detected by use of a modified enzyme-linked immunospot (ELISpot) assay with recombinant vaccinia virus, and CD4(+) cell responses were detected by use of ELISpot with recombinant HCV proteins core, nonstructural (NS) 3, and NS5. RESULTS Intrahepatic CD8(+) cell responses to HCV were detected in 7 of 10 patients coinfected with HCV and HIV (median frequency, 638 spot-forming cells [sfc]/1 x 10(6) cells) and were similar to those observed in patients singly infected with HCV (7/8; median, 647 sfc/1 x 10(6) cells). Intrahepatic HCV-specific CD4(+) cell responses were also comparable in both groups and correlated with the intrahepatic CD8(+) cell responses (r=0.59; P=.03). CONCLUSION HCV-specific CD8(+) cell responses are present in the liver of persons with chronic HCV infection even when they are coinfected with HIV; these correlate with intrahepatic HCV-specific CD4(+) cell responses.

Strong CD4 Th1 responses to HIV and hepatitis C virus in HIV-infected long-term non-progressors co-infected with hepatitis C virus.

Objectives To compare the T-cell responses to hepatitis C virus (HCV) and HIV in HIV-infected long-term non-progressors (LT-NP) and HIV-positive progressors co-infected with HCV and in HIV-negative HCV-infected patients. Methods Three groups were studied: 10 HCV/HIV-infected LT-NP, 26 HCV/HIV-infected progressors and 13 HCV-infected/HIV-negative patients. Virus-specific CD4 and CD8 T-cell responses in peripheral blood were assessed by interferon (IFN)-γ Elispot assays using recombinant proteins (HIV-p24 and three HCV antigens) and 16 HIV or HCV HLA A3- and/or HLA A2-restricted cytotoxic T lymphocytes peptides. Statistical analysis was performed with non-parametric tests. Results In addition to high T helper 1 (Th1) cell frequencies directed against HIV-p24, LT-NP had significantly (P < 0.05) higher frequencies of Th1 cells against HCV than the two other groups. No difference was observed between HIV-infected progressors and HIV-negative controls. Furthermore , HCV-specific CD4 and CD8 T cells were correlated in LT-NP (P = 0.006). Conclusion Thus, independently of the HIV-related immune alterations, LT-NP of the HIV-infection might have an intrinsic capacity to develop strong Th1 cell responses to viruses, particularly HIV and HCV.

T-cell clonal expansion in patients with B-cell lymphoproliferative disorders.

We investigated whether T-cell clonal expansion could be found in the blood of 14 untreated patients with B-cell lymphoproliferative disorders [5 B-chronic lymphocytic leukemia (CLL), 4 myelomas, 5 non-Hodgkin lymphoma (NHL)]. The putative presence of T-cell clonotypes was analyzed with a polymerase chain reaction-based method determining V-D-J junction size patterns in 24 T-cell receptor (TCR) Vβ subfamilies. This high-resolution method, analyzing CDR3 sizes of TCR transcripts, was used in conjunction with cytometric analysis of the corresponding T-cell sub-populations with 18 TCR Vβ-specific monoclonal antibody. We found multiple dominant T-cell clonotypes in the blood of most patients with B-CLL or myeloma as well of a patient with stage IV NHL. In some cases, T-cell clonal expansion was so dominant that the percentage of these clonal T-cell subpopulations in blood represented more than the mean + 2 SD value determined in a series of healthy controls. We conclude that a systemic antigen-specific (i.e., leading to clonotypic expansion) immune reaction involving few TCR clonotypes is a hallmark of disseminated B-cell malignancies. The nature of the putative antigens recognized is not known presently. Nonetheless, such insights into the T-cell repertoire of these patients may help to reassess the potential of immunotherapeutic strategies in B-cell malignancies.

Prognostic value of CA 15.3 kinetics for metastatic breast cancer

Up to 80% of breast cancer patients developing metastases have high levels of CA 15.3. We studied the prognostic implications of CA 15.3 kinetics in 119 patients before and at first metastasis by univariate and multivariate statistics. At first metastasis, CA 15.3 was elevated in 82.4% of patients, with a lead time (median 162 days) in 42.0% of them. Kaplan-Meier analysis showed overall survival (median 1477 days) to be significantly related to estrogen receptor (ER) and progesterone receptor (PgR) status (p=0.0001) and tumor size (p=0.025). The interval between diagnosis and first abnormal CA 15.3 (p=0.0001), the CA 15.3 concentration (p=0.013), and the presence or absence of a lead time (p=0.001) also had prognostic value. ER and PgR status (p=0.0005 and p=0.0103, respectively), metastasis-free interval (p=0.0003), existence of a CA 15.3 lead time (p=0.0028), and days from diagnosis to first abnormal CA 15.3 (p=0.0055) entered in the Cox model. After first metastasis (median survival 573 days), ER and PgR status (p=0.0001 and p=0.0004, respectively), existence of a lead time for CA 15.3 (p=0.0138), and the concentration of first abnormal CA 15.3 (p=0.0145) had individual prognostic value. In the Cox model ER status (p=0.0001), nodal status (p=0.0191), existence of a lead time for CA 15.3 (p=0.0033), days from diagnosis to first abnormal CA 15.3 (p=0.0132), and concentration of first abnormal CA 15.3 (p=0.0320) were found to be independent prognostic variables. Compared to a matched historical control group that was not monitored by CA 15.3 assaying (n=140), the study group had a significantly longer survival after the first metastasis (p=0.0005). In conclusion, the kinetics of CA 15.3 before the first metastasis is of prognostic value. When associated with 18-fluorodeoxyglucose imaging, serial CA 15.3 assays may help to implement early treatment of metastases.

Adoptive Transfer of Invariant NKT Cells as Immunotherapy for Advanced Melanoma: A Phase I Clinical Trial

Purpose: Invariant NKT cells (iNKT) are innate-like CD1d-restricted T cells with immunoregulatory activity in diseases including cancer. iNKT from advanced cancer patients can have reversible defects including IFNγ production, and iNKT IFNγ production may stratify for survival. Previous clinical trials using iNKT cell activating ligand α-galactosylceramide have shown clinical responses. Therefore, a phase I clinical trial was performed of autologous in vitro expanded iNKT cells in stage IIIB–IV melanoma. Experimental Design: Residual iNKT cells [<0.05% of patient peripheral blood mononuclear cell (PBMC)] were purified from autologous leukapheresis product using an antibody against the iNKT cell receptor linked to magnetic microbeads. iNKT cells were then expanded with CD3 mAb and IL2 in vitro to obtain up to approximately 109 cells. Results: Expanded iNKT cells produced IFNγ, but limited or undetectable IL4 or IL10. Three iNKT infusions each were completed on 9 patients, and produced only grade 1–2 toxicities. The 4th patient onward received systemic GM-CSF with their second and third infusions. Increased numbers of iNKT cells were seen in PBMCs after some infusions, particularly when GM-CSF was also given. IFNγ responses to α-galactosylceramide were increased in PBMCs from some patients after infusions, and delayed-type hypersensitivity responses to Candida increased in 5 of 8 evaluated patients. Three patients have died, three were progression-free at 53, 60, and 65 months, three received further treatment and were alive at 61, 81, and 85 months. There was no clear correlation between outcome and immune parameters. Conclusions: Autologous in vitro expanded iNKT cells are a feasible and safe therapy, producing Th1-like responses with antitumor potential. Clin Cancer Res; 23(14); 3510–9. ©2017 AACR.

Hepatitis C Virus-Specific T cell-Derived Transforming Growth Factor beta is Associated with Slow Hepatic Fibrogenesis

Hepatitis C virus (HCV)‐specific immune effector responses can cause liver damage in chronic infection. Hepatic stellate cells (HSC) are the main effectors of liver fibrosis. TGFβ, produced by HCV‐specific CD8+ T cells, is a key regulatory cytokine modulating HCV‐specific effector T cells. Here we studied TGFβ as well as other factors produced by HCV‐specific intrahepatic lymphocytes (IHL) and peripheral blood cells in hepatic inflammation and fibrogenesis. This was a cross‐sectional study of two well‐defined groups of HCV‐infected subjects with slow (≤0.1 Metavir units/year, n = 13) or rapid (n = 6) liver fibrosis progression. HCV‐specific T‐cell responses were studied using interferon‐gamma (IFNγ)‐ELISpot ±monoclonal antibodies (mAbs) blocking regulatory cytokines, along with multiplex, enzyme‐linked immunosorbent assay (ELISA) and multiparameter fluorescence‐activated cell sorting (FACS). The effects of IHL stimulated with HCV‐core peptides on HSC expression of profibrotic and fibrolytic genes were determined. Blocking regulatory cytokines significantly raised detection of HCV‐specific effector (IFNγ) responses only in slow fibrosis progressors, both in the periphery (P = 0.003) and liver (P = 0.01). Regulatory cytokine blockade revealed HCV‐specific IFNγ responses strongly correlated with HCV‐specific TGFβ, measured before blockade (R = 0.84, P = 0.0003), with only a trend to correlation with HCV‐specific IL‐10. HCV‐specific TGFβ was produced by CD8 and CD4 T cells. HCV‐specific TGFβ, not interleukin (IL)‐10, inversely correlated with liver inflammation (R = −0.63, P = 0.008) and, unexpectedly, fibrosis (R = −0.46, P = 0.05). In addition, supernatants from HCV‐stimulated IHL of slow progressors specifically increased fibrolytic gene expression in HSC and treatment with anti‐TGFβ mAb abrogated such expression. Conclusion: Although TGFβ is considered a major profibrogenic cytokine, local production of TGFβ by HCV‐specific T cells appeared to have a protective role in HCV‐infected liver, together with other T‐cell‐derived factors, ameliorating HCV liver disease progression. (HEPATOLOGY 2012;56:2094–2105)