Hicham Bouhlal

Opsonization of HIV-1 by Semen Complement Enhances Infection of Human Epithelial Cells

In the present study we demonstrate that both X4- and R5-tropic HIV-1 strains are able to infect the human epithelial cell line HT-29. Infection was enhanced 2-fold when HIV was added to semen before contact with the cell cultures. The enhancing effect of semen was complement dependent, as evidenced by blockage of generation of C3a/C3adesArg in semen by heat or EDTA treatment of semen and suppression of semen-dependent enhancement with mAbs directed to complement receptor type 3 (CD11b/CD18) and soluble CD16. Infection of HT-29 cells was assessed by the release of p24 Ag in cultures and semiquantitative PCR of the HIV-1 pol gene. Inhibition of infection of HT-29 by stromal cell-derived factor 1 was decreased in the case of semen-opsonized X4- and R5-tropic virus compared with unopsonized virus. In contrast, inhibition of infection by RANTES was increased for opsonized X4-tropic HIV-1 compared with unopsonized virus. Taken together these observations indicate that activation of complement in semen may play an enhancing role in mucosal transmission of HIV-1 by facilitating infection of epithelial cells and/or enhancing infection of complement receptor-expressing target cells in the mucosa.

Secretory Leukocyte Protease Inhibitor Inhibits Infection of Monocytes and Lymphocytes with Human Immunodeficiency Virus Type 1 but Does Not Interfere with Transcytosis of Cell- Associated Virus across Tight Epithelial Barriers

ABSTRACT In the present study, we demonstrate that recombinant human secretory leukocyte protease inhibitor (rhSLPI) inhibits infection of lymphocyte- and monocyte-derived tumor cell lines and peripheral blood lymphocytes with laboratory-adapted isolates and with the primary isolate, NDK, of free human immunodeficiency virus type 1 (HIV-1). In contrast, rhSLPI did not exhibit inhibitory activity toward transcytosis of cell-associated HIV-1 through a tight monolayer of endometrial epithelial cells. These observations indicate that the inhibitory effect of SLPI is restricted to free HIV-1 in corporal fluids.

Antibodies to C-C Chemokine Receptor 5 in Normal Human IgG Block Infection of Macrophages and Lymphocytes with Primary R5-Tropic Strains of HIV-1

In the present study, we demonstrate that normal human IgG for therapeutic use (i.v. Ig) contains natural Abs directed against the CCR5 coreceptor for HIV-1. Abs to CCR5 were isolated from i.v. Ig using an affinity matrix consisting of a synthetic peptide corresponding to the N-terminus of CCR5 coupled to Sepharose. Natural anti-CCR5 Abs inhibited the binding of RANTES to macrophages, demonstrating their interaction with the coreceptor of R5-tropic HIV-1. Affinity-purified anti-CCR5 Ig further inhibited infection of lymphocytes and monocytes/macrophages with primary and laboratory-adapted strains of HIV-1, but did not inhibit infection with X4-tropic HIV. Our results suggest that anti-CCR5 Abs from healthy immunocompetent donors may be suitable for development of novel passive immunotherapy regimens in specific clinical settings in HIV infection.

Real-Time PCR Quantification of Genital Shedding of Herpes Simplex Virus (HSV) and Human Immunodeficiency Virus (HIV) in Women Coinfected with HSV and HIV

ABSTRACT The accuracy and usefulness of laboratory-developed real-time PCR procedures using a Light Cycler instrument (Roche Diagnostics) for detecting and quantifying human immunodeficiency virus type 1 (HIV-1) RNA and DNA as well as herpes simplex virus type 1 (HSV-1)/HSV-2 DNA in cervicovaginal secretions from women coinfected with HIV and HSV were evaluated. For HIV-1, the use of the NEC152 and NEC131 primer set and the NEC-LTR probe in the long terminal repeat gene allowed us to detect accurately the majority of HIV-1 subtypes of group M circulating in sub-Saharan Africa, including subtypes A, B, C, D, and G as well as circulating recombinant forms 02 and 11. The detection threshold of real-time PCR for HIV in cervicovaginal lavage samples was 5 copies per assay for both RNA and DNA; the intra- and interassay coefficients of variation of CT values were 1.30% and 0.69% (HIV-1 RNA) and 1.84% and 0.67% (HIV-1 DNA), respectively. Real-time PCR for HSV using primers and probe targeting the HSV DNA polymerase gene allowed both detection and quantification of HSV DNA and also differentiation between HSV-1 and HSV-2 genotypes. The detection threshold of real-time PCR for HSV was 5 copies per assay; the intra- and interassay coefficients of variation of CT values were 0.96% and 1.49%, respectively. Both manual and automated silica-based procedures were appropriate for combined extraction of HIV and HSV genomes from female genital secretions. Taken together, these findings indicate that real-time PCR may be used as a unique nucleic acid amplification procedure to detect and quantify HIV and HSV genomes in cervicovaginal secretions and thus to assess at reduced costs the genital shedding of both viruses in women included in intervention studies.

Active and Selective Transcytosis of Cell-Free Human Immunodeficiency Virus through a Tight Polarized Monolayer of Human Endometrial Cells

ABSTRACT We report that both primary and laboratory-adapted infectious human immunodeficiency virus type 1 (HIV-1) isolates in a cell-free form are capable of transcytosis through a tight and polarized monolayer of human endometrial cells. Trancytosis of cell-free HIV occurs in a strain-selective fashion and appears to be dependent on interactions between HIV envelope glycoproteins and lectins on the apical membrane of the epithelial cells. These findings provide new insights into the initial events occurring during heterosexual transmission of the virus.

STAT3 transcription factor is constitutively activated and is oncogenic in nasal-type NK/T-cell lymphoma

Nasal-type natural killer (NK) cell lymphoma is an infrequent aggressive malignant disease with very poor prognosis. We aimed to explore the possible role of the transcription factor STAT3 in the pathophysiology of this malignancy, as it was involved in oncogenesis and chemoresistance. For this, we established and characterized a continuous interleukin 2-dependent NK cell line (MEC04) from a patient with a fatal nasal-type NK-cell lymphoma. Cells harbored poor cytotoxic activity against K562 cells, and spontaneously secreted interferon-γ, interleukin-10 and vascular-endothelium growth factor in vitro. STAT3 was phosphorylated in Y705 dimerization residue in MEC04 cells and restricted to the nucleus. Y705 STAT3 phosphorylation involved JAK2, as exposure of cells to AG490 inhibitor inhibited Y705 STAT3 phosphorylation. By using recombinant transducible TAT-STAT3-β (β isoform), TAT-STAT3Y705F (a STAT3 protein mutated on Y705 residue, which prevents STAT3 dimerization) and peptides inhibiting specifically STAT3 dimerization, we inhibited STAT3 phosphorylation and cell growth, with cell death induction. Finally, STAT3 was phosphorylated in Y705 residue in the nuclei of lymphoma cells in eight/nine patients with nasal-type NK/T-cell lymphoma and in YT, another NK cell line. Our results suggest that STAT3 protein has a major role in the oncogenic process of nasal-type NK-cell lymphomas, and may represent a promising therapeutical target.

Restoration of Normal Interleukin-2 Production by CD4+ T Cells of Human Immunodeficiency Virus-Infected Patients after 9 Months of Highly Active Antiretroviral Therapy

The present study investigated immune restoration in patients at intermediate stages of human immunodeficiency virus (HIV) disease after initiation of highly active antiretroviral therapy (HAART). A progressive increase in both memory and naive CD4+ T cells was observed from the first weeks of therapy, concomitant with a decrease in the expression of activation markers on CD8+ T cells. The early-activation marker CD69 remained, however, overexpressed on T cells after suboptimal stimulation in vitro, indicative of persistent immune activation. The percentage of interleukin (IL)-2-producing CD4+ T cells significantly increased from 9 months of HAART. In most patients, CD4+ T cells recovered an ability to produce IL-2 on stimulation, similar to that of HIV-seronegative controls. Reversal of T-cell anergy may be a key event in immune restoration for achieving long-term clinical benefit with HAART.

Opsonization of HIV with Complement Enhances Infection of Dendritic Cells and Viral Transfer to CD4 T Cells in a CR3 and DC-SIGN-Dependent Manner

In the present study, we demonstrated that opsonization of primary HIV-1 with human complement enhances infection of immature monocyte-derived dendritic cells (iDC) and transmission in trans of HIV to autologous CD4+ T lymphocytes. Infection of iDC by opsonized primary R5- and X4-tropic HIV was increased 3- to 5-fold as compared with infection by the corresponding unopsonized HIV. Enhancement of infection was dependent on CR3 as demonstrated by inhibition induced by blocking Abs. The interaction of HIV with CCR5 and CXCR4 on iDC was affected by opsonization. Indeed, stromal-derived factor-1 was more efficient in inhibiting infection of iDC with opsonized R5-tropic HIV-1BaL (45%) than with heat-inactivated complement opsonized virus and similarly RANTES inhibited more efficiently infection of iDC with opsonized X4-tropic HIV-1NDK (42%) than with heat-inactivated complement opsonized virus. We also showed that attachment of complement-opsonized virus to DC-specific ICAM-grabbing nonintegrin (DC-SIGN) molecule on iDC and HeLa DC-SIGN+ CR3− cells was 46% and 50% higher compared with heat-inactivated complement opsonized virus, respectively. Hence, Abs to DC-SIGN suppressed up to 80% and 60% the binding of opsonized virus to HeLa cells and iDC, respectively. Furthermore, Abs to DC-SIGN inhibited up to 70% of the infection of iDC and up to 65% of infection in trans of autologous lymphocytes with opsonized virus. These results further demonstrated the role of DC-SIGN in complement opsonized virus uptake and infection. Thus, the virus uses complement to its advantage to facilitate early steps leading to infection following mucosal transmission of HIV.

Inhibition of HIV-1 transmission in trans from dendritic cells to CD4+ T lymphocytes by natural antibodies to the CRD domain of DC-SIGN purified from breast milk and intravenous immunoglobulins

The present study demonstrates that human breast milk and normal human polyclonal immunoglobulins purified from plasma [intravenous immunoglobulins (IVIg)] contain functional natural immunoglobulin A (IgA) and IgG antibodies directed against the carbohydrate recognition domain (CRD) domain of the dendritic cell‐specific intercellular adhesion molecule‐3‐grabbing non‐integrin (DC‐SIGN) molecule, which is involved in the binding of human immunodeficiency virus (HIV)‐1 to dendritic cells (DCs). Antibodies to DC‐SIGN CRD were affinity‐purified on a matrix to which a synthetic peptide corresponding to the N‐terminal CRD domain (amino‐acid 342–amino‐acid 371) had been coupled. The affinity‐purified antibodies bound to the DC‐SIGN peptide and to the native DC‐SIGN molecule expressed by HeLa DC‐SIGN+ cells and immature monocyte‐derived dendritic cells (iMDDCs), in a specific and dose‐dependent manner. At an optimal dose of 200 µg/ml, natural antibodies to DC‐SIGN CRD peptide purified from breast milk and IVIg stained 25 and 20% of HeLa DC‐SIGN+ cells and 32 and 12% of iMDDCs, respectively. Anti‐DC‐SIGN CRD peptide antibodies inhibited the attachment of virus to HeLa DC‐SIGN by up to 78% and the attachment to iMDDCs by only 20%. Both breast milk‐ and IVIg‐derived natural antibodies to the CRD peptide inhibited 60% of the transmission in trans of HIV‐1JRCSF, an R5‐tropic strain, from iMDDCs to CD4+ T lymphocytes. Taken together, these observations suggest that the attachment of HIV to DCs and transmission in trans to autologous CD4+ T lymphocytes occur through two independent mechanisms. Our data support a role of natural antibodies to DC‐SIGN in the modulation of postnatal HIV transmission through breast‐feeding and in the natural host defence against HIV‐1 in infected individuals.

Impact of acyclovir on genital and plasma HIV-1 RNA, genital herpes simplex virus type 2 DNA, and ulcer healing among HIV-1-infected African women with herpes ulcers: a randomized placebo-controlled trial.

BACKGROUND Little is known about the impact of episodic treatment of herpes on human immunodeficiency virus type 1 (HIV-1). METHODS Women from Ghana and the Central African Republic who had genital ulcers were enrolled in a randomized, double-blind, placebo-controlled trial of acyclovir plus antibacterials and were monitored for 28 days. Ulcer etiologies and detection of lesional HIV-1 RNA were determined by polymerase chain reaction (PCR). Cervicovaginal HIV-1 RNA and herpes simplex virus type 2 (HSV-2) DNA and plasma HIV-1 RNA were quantitated by real-time PCR. Primary analyses included 118 HIV-1-infected women with HSV-2 ulcers (54 of whom were given acyclovir and 64 of whom were given placebo). RESULTS Acyclovir had little impact on (1) detection of cervicovaginal HIV-1 RNA (risk ratio [RR], 0.96; 95% confidence interval [CI], 0.8-1.2) at day 7 of treatment, (2) the mean cervicovaginal HIV-1 RNA load (-0.06 log(10) copies/mL; 95% CI, -0.4 to 0.3 log(10) copies/mL) at day 7 of treatment, or (3) the plasma HIV-1 RNA load (+0.09 log(10) copies/mL; 95% CI, -0.1 to 0.3 log(10) copies/mL) at day 14 of treatment. At day 7, women receiving acyclovir were less likely to have detectable lesional HIV-1 RNA (RR, 0.70; 95% CI, 0.4-1.2) or cervicovaginal HSV-2 DNA (RR, 0.69; 95% CI, 0.4-1.3), had a lower quantity of HSV-2 DNA (-0.99 log(10) copies/mL; 95% CI, -1.8 to -0.2 log(10) copies/mL), and were more likely to have a healed ulcer (RR, 1.26; 95% CI, 0.9-1.9). CONCLUSION Episodic therapy for herpes reduced the quantity of cervicovaginal HSV-2 DNA and slightly improved ulcer healing, but it did not decrease genital and plasma HIV-1 RNA loads. TRIAL REGISTRATION ClinicalTrials.gov identifier NCT00158483 .