Interleukin-7 signalling is sufficient to phenotypically and functionally prime human CD4 naive T cells

Blockade of IL-7Rα alleviates collagen-induced arthritis via inhibiting Th1 cell differentiation and CD4+ T cell migration

T cell response is crucial to the pathogenesis and progression of rheumatoid arthritis (RA). IL-7/IL-7R axis has significant effect on CD4⁺ T cell response, including proliferation, differentiation, survival and migration. However, whether blockade of IL-7/IL-7R axis signaling can relieve RA and what is the potential treatment mechanisms are still remaining unclear. In this paper, we established collagen-induced arthritis (CIA) model and observed the effect of IL-7Rα antibody in the treatment of CIA mice. It is demonstrated that IL-7Rα antibody significantly alleviated clinical symptoms of CIA mice, accompanied with reduced CD4⁺ T cell number in both spleen and joints. Decreased CII-specific CD4⁺ T cell proliferation and reduced mRNA expression of inflammatory cytokines in IL-7Rα antibody-treated mice were observed. Subsequently, IL-7Rα antibody treatment in vivo downregulated the percentages of Th1 and Th17 cells and the mRNA expression of T-bet and RORγt gene. Moreover, it was found that IL-7 promoted Th1 cell differentiation in vitro, while having no effect on Th17 cell differentiation. In addition, administration of IL-7Rα antibody reduced the mRNA expression of chemokine receptors (CCR7, CXCR3, CXCR6 and XCR1) on CD4⁺ T cells and chemokine CXCL2 in joints. The results suggested that IL-7Rα antibody treated CIA mice via the inhibition of CII-specific CD4⁺ T cell proliferation, the reduction of Th1 cell differentiation and the restrain of CD4⁺ T cell migration to joint lesion site. This investigation indicates that IL-7Rα is a potential therapeutic target for RA.

The role of cytokines in the pathogenesis and treatment of HIV infection

HIV immune activation plays an important role in the immunopathogenesis of the disease. The mechanisms driving this immune activation are partially defined and likely are the result of multiple factors. The introduction of combination antiretroviral therapy (cART) has improved the life expectancy of HIV infected individuals, however there is evidence that in the setting of "undetectable" HIV-RNA plasma levels, there is some level of persistent immune activation in these patients. A better understanding of the immune activation pathways should be of value in developing complementary therapies to restore the immune systems of patients with HIV infection. This review discusses the cytokine mediated pathways of immune activation of the CD4 and CD8 T cell pools during HIV infection.

Role of CXCR3 ligands in IL-7/IL-7R alpha-Fc-mediated antitumor activity in lung cancer

PURPOSE

We evaluated the utility of chimeric γc homeostatic cytokine, IL-7/IL-7Rα-Fc, to restore host APC (antigen presenting cell) and T cell activities in lung cancer.

EXPERIMENTAL DESIGN

Utilizing murine lung cancer models we determined the antitumor efficacy of IL-7/IL-7Rα-Fc. APC, T cell, cytokine analyses, neutralization of CXCL9, CXCL10, and IFNγ were carried out to evaluate the mechanistic differences in the antitumor activity of IL-7/IL-7Rα-Fc in comparison to controls.

RESULTS

IL-7/IL-7Rα-Fc administration inhibited tumor growth and increased survival in lung cancer. Accompanying the tumor growth inhibition were increases in APC and T cell activities. In comparison to controls, IL-7/IL-7Rα-Fc treatment of tumor bearing mice led to increased: (i) levels of CXCL9, CXCL10, IFNγ, IL-12 but reduced IL-10 and TGFβ, (ii) tumor macrophage infiltrates characteristic of M1 phenotype with increased IL-12, iNOS but reduced IL-10 and arginase, (iii) frequencies of T and NK cells, (iv) T cell activation markers CXCR3, CD69 and CD127(low), (v) effector memory T cells, and (vi) T cell cytolytic activity against parental tumor cells. IL-7/IL-7Rα-Fc treatment abrogated the tumor induced reduction in splenic functional APC activity to T responder cells. The CXCR3 ligands played an important role in IL-7/IL-7Rα-Fc-mediated antitumor activity. Neutralization of CXCL9, CXCL10, or IFNγ reduced CXCR3 expressing activated T cells infiltrating the tumor and abrogated IL-7/IL-7Rα-Fc-mediated tumor growth inhibition.

CONCLUSIONS

Our findings show that IL-7/IL-7Rα-Fc promotes afferent and efferent antitumor responses in lung cancer.

Interleukin-7 permits Th1/Tc1 maturation and promotes ex vivo expansion of cord blood T cells: a critical step toward adoptive immunotherapy after cord blood transplantation

Donor leukocyte infusions (DLI) in the allogeneic hematopoietic transplant setting can provide a clinically relevant boost of immunity to reduce opportunistic infections and to increase graft-versus-leukemia activity. Despite significant advances in applicability, DLI has not been available for single-unit recipients of unrelated cord blood transplant. Ex vivo expansion of cord blood T cells can be achieved with interleukin (IL)-2 and CD3/CD28 costimulatory beads. However, significant apoptosis occurs in proliferating T cells, diminishing the yield and skewing the CD4/CD8 ratio in the T-cell population, jeopardizing the potential efficacy of DLI. In this study, we show that interleukin (IL)-7 not only reduces apoptosis of activated T lymphocytes and enhances their proliferation but also promotes functional maturation, leading to secretion of IFN-gamma and other key cytokines. Recognizing that infused T lymphocytes will need to meet microbial antigens in secondary lymphoid organs to generate effectors, we also show that expansion with IL-7 promotes the preservation of a polyclonal broad T-cell receptor repertoire and a surface phenotype that favors lymph node homing. Expanded lymphocytes lack alloreactivity against recipient and other allogeneic cells, indicating a favorable safety profile from graft-versus-host disease. Nevertheless, expanded T cells can be primed subsequently against lymphoid and myeloid leukemia cells to generate tumor-specific cytotoxic T cells. Taken together, our findings offer a major step in fulfilling critical numerical and biological requirements to quickly generate a DLI product ex vivo using a negligible fraction of a cord blood graft that provides a flexible adoptive immunotherapy platform for both children and adults.

Human adipose tissue macrophages: m1 and m2 cell surface markers in subcutaneous and omental depots and after weight loss

CONTEXT

Macrophages accumulate in adipose tissue and possibly participate in metabolic complications in obesity. Macrophage number varies with adipose tissue site and weight loss, but whether this is accompanied by phenotypic changes is unknown.

OBJECTIVE

The objective of the study was to characterize the activation state of adipose tissue macrophages in human obesity.

DESIGN/SETTING

We performed a single-center prospective study.

PARTICIPANTS/INTERVENTIONS

Paired biopsies of sc and omental adipose tissue were obtained during gastric surgery in 16 premenopausal obese women (aged 41.1 +/- 8.6 yr; body mass index 43.8 +/- 3.4 kg/m(2)). Subcutaneous adipose tissue biopsies were obtained 3 months later in obese subjects and in 10 nonobese women (aged 43.3 +/- 3.5 yr; body mass index 22.5 +/- 0.75 kg/m(2)). The number of macrophages stained with CD40, CD206, and CD163 surface markers was determined by immunochemistry.

MAIN OUTCOMES

The number of CD40(+) macrophages significantly increased with obesity and in omental vs. sc adipose tissue in obese women. No significant changes in CD163(+) and CD206(+) macrophage counts was found with obesity and fat pad anatomical location. Three months after gastric surgery, the ratio of CD40(+) to CD206(+) macrophages was 2-fold lower than before surgery in the sc adipose tissue of obese subjects (P < 0.001) due to a concomitant decrease of CD40(+) and increase of CD206(+) macrophages counts.

CONCLUSION

We suggest that the activation state of adipose tissue macrophages is weighted toward M1 over M2 status in obese subjects and switch to a less proinflammatory profile 3 months after gastric bypass.

Effect of mucosal fluid from women with bacterial vaginosis on HIV trans-infection mediated by dendritic cells

Women with bacterial vaginosis (BV) have a higher risk of HIV transmission but the cause of risk is unknown. Dendritic cells (DC) are implicated in transmission of HIV and we previously observed that DC mature when exposed to mucosal fluid from women with BV. We hypothesized that maturation of DC by BV mucosal fluid would enhance DC-mediated trans-infection of HIV. Monocyte-derived DC (MDDC) were treated with mucosal fluid, incubated with HIV(Bal), and HIV trans-infection was evaluated. While LPS-treated MDDC increased HIV(Bal)trans-infection, BV fluid reduced trans-infection. HIV(Bal) DNA levels in MDDC were not affected by BV fluid or LPS but productive infection of MDDC was decreased by LPS and BV fluid. Mucosal fluid from women with BV does not increase MDDC-mediated trans-infection suggesting that BV does not increase HIV susceptibility by increasing DC-mediated trans-infection. However, indirect effects of DC maturation on HIV transmission cannot be ruled out.

Herpes simplex virus type 1 dysregulates anti-fungal defenses preventing monocyte activation and downregulating toll-like receptor-2

We investigated the interplay occurring between pathogens in the course of dual infections, using an in vitro model in which the THP-1 monocytic cell line is first infected with HSV-1 and then exposed to Ca or Cn. These three pathogens share some pathogenic features: they cause opportunistic infections, target macrophages and are neurotropic. Here, we show that HSV-1-infected THP-1 cells exhibited augmented phagocytosis against the two opportunistic fungi but reduced capability to counteract fungal infection: the better ingestion by monocytes was followed by facilitated fungal survival and replication. Reduced IL-12 production was also observed. Cytofluorimetric analysis showed that HSV-1-infected monocytes exhibit: (i) downregulated TLR-2 and TLR-4, critical structures in fungal recognition; (ii) reduced expression of CD38 and CD69, known to be important markers of monocyte activation; and (iii) enhanced expression of apoptosis and necrosis markers, in the absence of altered cell proliferation. Overall, these findings imply that HSV-1 infection prevents monocyte activation, thus leading to a significant dysfunction of the monocyte-mediated anti-Candida response; HSV-1 induced apoptosis and necrosis of monocytes further contribute to this impairment.

Enhancement of human antigen-specific memory T-cell responses by interleukin-7 may improve accuracy in diagnosing tuberculosis

Children and immunocompromised adults are at an increased risk of tuberculosis (TB), but diagnosis is more challenging. Recently developed gamma interferon (IFN-gamma) release assays provide increased sensitivity and specificity for diagnosis of latent TB, but their use is not FDA approved in immunocompromised or pediatric populations. Both populations have reduced numbers of T cells, which are major producers of IFN-gamma. Interleukin 7 (IL-7), a survival cytokine, stabilizes IFN-gamma message and increases protein production. IL-7 was added to antigen-stimulated lymphocytes to improve IFN-gamma responses as measured by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay. Antigens used were tetanus toxoid (n = 10), p24 (from human immunodeficiency virus [HIV], n = 9), and TB peptides (n = 15). Keyhole limpet hemocyanin was used as a negative control, and phytohemagglutinin was the positive control. IL-7 improved antigen-specific responses to all antigens tested including tetanus toxoid, HIV type 1 p24, and TB peptides (ESAT-6 and CFP-10) with up to a 14-fold increase (mean = 3.8), as measured by ELISA. Increased IFN-gamma responses from controls, HIV-positive patients, and TB patients were statistically significant, with P values of <0.05, 0.01, and 0.05, respectively. ELISPOT assay results confirmed ELISA findings (P values of <0.01, 0.02, and 0.03, respectively), with a strong correlation between the two tests (R(2) = 0.82 to 0.99). Based on average background levels, IL-7 increased detection of IFN-gamma by 39% compared to the level with antigen alone. Increased production of IFN-gamma induced by IL-7 improves sensitivity of ELISA and ELISPOT assays for all antigens tested. Further enhancement of IFN-gamma-based assays might improve TB diagnosis in those populations at highest risk for TB.

Priming of T cells to Fas-mediated proliferative signals by interleukin-7

T-cell depletion associated with HIV infection or cytoreductive therapies triggers potential T-cell regenerative mechanisms such as peripheral T-lymphocyte expansion to weak antigenic stimuli and the increased availability of interleukin-7 (IL-7), a cytokine with potent antiapoptotic and proliferative activities. Deleterious mechanisms also associated with lymphopenia, such as increased Fas expression and apoptosis of T cell, however, may result in opposing effects. In this study, we show that Fas molecules, primarily associated with T-cell depletion in lymphopenic settings, may also contribute to compensatory T-cell expansion through transmitting costimulatory signals to suboptimally activated T cells. Proliferation of T lymphocytes in response to concomitant Fas and T-cell receptor (TCR) triggering was shown to be increased in HIV-infected individuals compared with noninfected controls. As IL-7 levels are often elevated in lymphopenic individuals in association with increased Fas expression, we analyzed whether IL-7 would influence Fas-mediated proliferative signals in T cells. We show that IL-7 is able to increase the efficacy of Fas to induce proliferation of suboptimally activated T cells. Thus, high IL-7 levels associated with lymphopenic conditions may simultaneously induce sensitivity to Fas-mediated apoptosis in nonactivated T cells and increase Fas-induced costimulatory signals in T cells recognizing low-affinity antigens.

Disruption of the gamma c cytokine network in T cells during HIV infection

The common gamma chain (gammac)-sharing cytokines (IL's-2, 4, 7, 9, 15, and 21) play a vital role in the survival, proliferation, differentiation and function of T lymphocytes. As such, disruption of their signaling pathways would be expected to have severe consequences on the integrity of the immune system. Indeed, it appears that the signaling network of these cytokines is both disrupted and exploited by HIV at various stages of infection. IL-2 secretion and signaling downstream of its receptor are impaired in T cells from chronically-infected HIV+ patients. Elevated plasma IL-7 levels and decreased IL-7Ralpha expression in patient T cells results in significantly decreased responsiveness to this critical cytokine. Interestingly, IL-2 and IL-15 are also able to render CD4+ T cells permissive to HIV infection through their influence on the activity of the APOBEC3G deaminase enzyme. Herein, we describe the current state of knowledge on how the gammac cytokine network is affected during HIV infection, with a focus on how this impairs CD4+ and CD8+ T cell function while also benefiting the virus itself. We also address the use of cytokines as adjuncts to highly active antiretroviral therapy to bolster immune reconstitution in infected patients.

Potential Role for IL-7 in Fas-Mediated T Cell Apoptosis During HIV Infection

IL-7 promotes survival of resting T lymphocytes and induces T cell proliferation in lymphopenic conditions. As elevated IL-7 levels occur in HIV-infected individuals in addition to high Fas expression on T cells and increased sensitivity to Fas-induced apoptosis, we analyzed whether IL-7 has a regulatory role in Fas-mediated T cell apoptosis. We show that IL-7 up-regulates Fas expression on naive and memory T cells through a mechanism that involves translocation of Fas molecules from intracellular compartments to the cell membrane. IL-7 induced the association of Fas with the cytoskeletal component ezrin and a polarized Fas expression on the cell surface. The potential role of IL-7 in Fas up-regulation in vivo was verified in IL-7-treated macaques and in HIV-infected or chemotherapy treated patients by the correlation between serum IL-7 levels and Fas expression on T cells. IL-7 treatment primed T cells for Fas-induced apoptosis in vitro and serum IL-7 levels correlated with the sensitivity of T cells to Fas-induced apoptosis in HIV-infected individuals. Our data suggest an important role for IL-7 in Fas-mediated regulation of T cell homeostasis. Elevated IL-7 levels associated with lymphopenic conditions, including HIV-infection, might participate in the increased sensitivity of T cells for activation-induced apoptosis.

Recombinant IL-7 enhances the potency of GM-CSF-secreting tumor cell immunotherapy

IL-7 is known for its role in lymphopoiesis and T-cell homeostasis. In addition, its capacity to augment the immune response to weak or low affinity antigens makes it an ideal candidate to evaluate in combination with a GM-CSF-secreting tumor cell immunotherapy, which has been shown to elicit broad humoral and cellular immune responses. The studies reported here show that IL-7, when combined with a GM-CSF-secreting tumor cell immunotherapy, significantly prolonged the survival of tumor-bearing mice. The enhanced anti-tumor protection correlated with an increased number of activated dendritic cells (DC) and T cells in lymphoid tissues, such as the draining lymph nodes (DLN) and spleen. Moreover, an increased number of activated effector T cells were found in the tumor microenvironment, correlating with a more potent systemic tumor-specific T-cell response than each monotherapy alone. Taken together, these studies demonstrate that IL-7 augments the anti-tumor response of a GM-CSF-secreting tumor cell immunotherapy in preclinical models.

Interleukin-7–Engineered Mesenchymal Cells: In Vitro Effects on Naive T-Cell Population

T-cell homeostasis is regulated by several molecules; among these, interleukin (IL)-7 plays an essential role in the survival and homeostatic proliferation of peripheral naive T cells. In a previous study, we investigated whether human mesenchymal stromal cells (MSCs) could be engineered with the IL-7 gene to produce functional level of this cytokine. In the present study, we analyzed the impact of different quantities of IL-7 produced by MSCs on the survival and proliferation of a negative immunoselected naive (CD3(+)/CD45RA(+)) T-cell population. Co-cultivation of peripheral naive T cells with MSCs producing low (16 pg/mL) or high (1000 pg/mL) IL-7 levels or in the presence of exogenous IL-7 (0.01 ng/mL and 100 ng/mL) maintained the CD3(+)/CD45RA(+) naive T-cell phenotype. Chemokine receptor CCR7(+) expression was also maintained among this T-cell population. Naive T-cell molecular characteristics were maintained as assessed by the Vbeta spectratyping complexity score, which showed the maintenance of a broad T-cell repertoire. No Th1 or Th2 differentiation was observed, as assessed by interferon-gamma or IL-4 accumulation. In contrast, only MSCs producing high amounts of IL-7 caused increased activation (CD25 31.2% +/- 12% vs 10% +/- 3.5%; P < .05), proliferation (CD71 17.8+/-7% vs 9.3%+/-3, P < .05), apoptosis (assessed by annexin V: 18.6% +/- 5% vs 14.9% +/- 2.6%; P > .05), and the phase S cell cycle (15% vs 6.9%, P > .05). Exogenous IL-7 exhibited no significant effect. In conclusion, we demonstrated that IL-7 produced by MSCs has a dose-independent effect on naive T-cell survival while exerting a dose-dependent effect on activation/proliferation. Due to the continuous production of IL-7 by engineered cells, our system is more efficacious than exogenous IL-7.

IL-7-induced proliferation of recent thymic emigrants requires activation of the PI3K pathway

The IL-7 cytokine promotes the survival of a diverse T-cell pool, thereby ensuring an efficient immune response. Moreover, IL-7 induces the proliferation of recent thymic emigrants (RTEs) in neonates. Here, we demonstrate that the survival and proliferative effects of IL-7 on human RTEs can be distinguished on the basis of dose as well as duration of IL-7 administration. A dose of 0.1 ng/mL IL-7 is sufficient to promote viability, whereas cell-cycle entry is observed only at doses higher than 1 ng/mL. Moreover, a short 1-hour exposure to high-dose IL-7 (10 ng/mL) induces long-term survival but continuous IL-7 exposure is necessary for optimal cell-cycle entry and proliferation. We find that distinct signaling intermediates are activated under conditions of IL-7-induced survival and proliferation; STAT5 tyrosine phosphorylation does not correlate with proliferation, whereas up-regulation of the glucose transporter Glut-1 as well as increased glucose uptake are markers of IL-7-induced cell cycle entry. Glut-1 is directly regulated by PI3K and, indeed, inhibiting PI3K activity abrogates IL-7-induced proliferation. Our finding that the survival and proliferation of RTEs are differentially modulated by the dose and kinetics of exogenous IL-7 has important implications for the clinical use of this cytokine.

Interleukin-7 induces HIV replication in primary naive T cells through a nuclear factor of activated T cell (NFAT)-dependent pathway

Interleukin (IL)-7 plays several roles critical to T cell maturation, survival, and homeostasis. Because of these functions, IL-7 is under investigation as an immune-modulator for therapeutic use in lymphopenic clinical conditions, including HIV. We reported that naive T cells, typically not permissive to HIV, can be productively infected when pre-treated with IL-7. We evaluated the mechanism by which IL-7-mediates this effect. IL-7 potently up-regulated the transcriptional factor NFAT, but had no effect on NFkappaB. Blocking NFAT activity using a number of reagents, such as Cyclosporin A, FK-506, or the NFAT-specific inhibitor known as VIVIT peptide, all markedly reduced IL-7-mediated induction of HIV replication in naive T cells. Additional neutralization of cytokines present in IL-7-treated cultures and/or those that have NFAT-binding sequences within their promotors indicated that IL-10, IL-4, and most significantly IFNgamma, all contribute to IL-7-induction of HIV productive replication in naive T cells. These data clarify the mechanism by which IL-7 can overcome the block to HIV productive infection in naive T cells, despite their quiescent cell status. These findings are relevant to the treatment of HIV disease and understanding HIV pathogenesis in the naive CD4+ T cell compartment, especially in light of the vigorous pursuit of IL-7 as an in vivo immune modulator.

Correlation between the expressions of gastrin, somatostatin and cyclin and cyclin-depend kinase in colorectal cancer

AIM

To explore the correlation between the expressions of gastrin (GAS), somatostatin (SS) and cyclin, cyclin-dependent kinase (CDK) in colorectal cancer, and to detect the specific regulatory sites where gastrointestinal hormone regulates cell proliferation.

METHODS

Seventy-nine resected large intestine carcinomatous specimens were randomly selected. Immunohistochemical staining for GAS, SS, cyclin D1, cyclin E, cyclin A, cyclin B1, CDK2 and CDK4 was performed according to the standard streptavidin-biotin-peroxidase (S-P) method. According to the semi-quantitative integral evaluation, SS and GAS were divided into high, middle and low groups. Cyclin D1, cyclin E, cyclin A, cyclin B1, CDK2, CDK4 expressions in the three GAS and SS groups were assessed.

RESULTS

The positive expression rate of cyclin D1 was significantly higher in high (78.6%, 11/14) and middle GAS groups (73.9%, 17/23) than in low GAS group (45.2%, 19/42) (P<0.05, c2(high vs low) = 4.691; P<0.05, c2(middle vs low) = 4.945). The positive expression rate of cyclin A was significantly higher in high (100%, 14/14) and middle GAS groups (82.6%, 19/23) than in low GAS group (54.8%, 23/42) (P<0.01, c2(high vs low) = 9.586; P<0.05, c2(middle vs low) = 5.040). The positive expression rate of CDK2 was significantly higher in high (92.9%, 13/14) and middle GAS groups (87.0%, 20/23) than in low GAS group (50.0%, 21/42) (P<0.01, c2(high vs low) = 8.086; P<0.01, c2(middle vs low) = 8.715). The positive expression rate of CDK4 was significantly higher in high (78.6%, 11/14) and middle GAS groups (78.3%, 18/23) than in low GAS group (42.9%, 18/42) (P<0.05, c2(high vs low) = 5.364; P<0.01, c2(middle vs low) = 7.539). The positive expression rate of cyclin E was prominently higher in low SS group (53.3%, 24/45) than in high (9.1%, 1/11) and middle (21.7%, 5/23) SS groups (P<0.05, c2(high vs low) = 5.325; P<0.05, c2(middle vs low) = 6.212). The positive expression rate of CDK2 was significantly higher in low SS group (77.8%, 35/45) than in high SS group (27.3%, 3/11) (P<0.01, c2(high vs low) = 8.151). There was a significant positive correlation between the integral ratio of GAS to SS and the semi-quantitative integral of cyclin D1, cyclin E, cyclin A, CDK2, CDK4 (P<0.05, (D1)r(s) = 0.252; P<0.01, (E)r(s) = 0.387; P<0.01, (A)r(s) = 0.466; P<0.01, (K2)r(s) = 0.519; P<0.01, (K4)r(s) = 0.434).

CONCLUSION

The regulation and control of gastrin, SS in colorectal cancer cell growth may be directly related to the abnormal expressions of cyclins D1, A, E, and CDK2, CDK4. The regulatory site of GAS in the cell cycle of colorectal carcinoma may be at the G(1), S and G(2) phases. The regulatory site of SS may be at the entrance of S phase.

Evaluating the impact of hepatitis C virus (HCV) on highly active antiretroviral therapy-mediated immune responses in HCV/HIV-coinfected women: role of HCV on expression of primed/memory T cells

OBJECTIVE

To evaluate the impact of hepatitis C virus (HCV) on the immune system before receipt of highly active antiretroviral therapy (HAART) and on immune recovery after receipt of HAART among human immunodeficiency virus (HIV)/HCV-coinfected women enrolled in the Women's Interagency HIV Study.

METHODS

The study included 294 HIV-infected women who initiated HAART and attended 2 follow-up visits. The women were grouped on the basis of positive HCV antibody and HCV RNA tests. There were 148 women who were HCV antibody negative, 34 who were HCV antibody positive but RNA negative, and 112 who were HCV antibody and RNA positive. Immune recovery was measured by flow-cytometric assessment for markers of activation and maturation on CD4+ and CD8+ T cells. Data analysis used repeated measures of variance.Results. HIV/HCV coinfection is associated with an increased number of CD4+ and CD8+ primed/memory T cells. HIV/HCV coinfection, however, did not affect any further decreases in CD4+ or CD4+ and CD8+ naive/memory T cell counts or enhanced T cell activation. HIV/HCV coinfection also did not affect HAART responses in the CD4+ and CD8+ T cell compartment.

CONCLUSIONS

HCV does not affect immune responses to HAART in HIV/HCV-coinfected individuals but is associated with an expansion of CD4+ and CD8+ memory T cell subsets. Functional impairment in the CD4+ and CD8+ T cell compartments still needs to be assessed in coinfected patients.