Seminal shedding of human immunodeficiency virus type 1 and human cytomegalovirus: evidence for different immunologic controls

Increased frequency and quantity of mucosal and plasma cytomegalovirus replication among Ugandan Adults Living with HIV

BACKGROUND

Co-infection with HIV can result in impaired control of cytomegalovirus (CMV) replication, increasing the likelihood of disease and onward transmission. The objective of this analysis was to measure the impact of HIV on CMV replication in an intensively-sampled cohort in Kampala, Uganda.

METHODS

CMV seropositive men and women aged 18-65, with or without HIV co-infection, were followed for one month. Daily oral swabs and weekly anogenital swabs and plasma were collected. Quantitative CMV PCR was performed on all samples.

RESULTS

Eighty-five participants were enrolled and provided ≥1 oral swab; 43 (51%) were HIV-seropositive. People living with HIV (PLWH; median CD4 count 439 cells/mm3; none on antiretrovirals) had 2-4 times greater risk of CMV detection at each anatomical site assessed. At the oral site, 773 of 1272 (61%) of samples from PLWH had CMV detected, compared to 214 of 1349 (16%) among people without HIV. Similarly, the mean CMV quantity was higher among PLWH at all anatomical sites, with the largest difference seen for oral swabs (mean difference 1.63 log/mL; 95% CI 1.13-2.13). Among PLWH, absolute quantity of CD4+ T-cells was not associated with risk of CMV detection. HIV plasma RNA quantity was positively correlated with oral CMV shedding frequency, but not detection at other sites.

CONCLUSIONS

Mucosal and systemic CMV replication occurs at higher levels in PLWH than people without HIV, particularly oral shedding, which is a major mode of CMV transmission. Increased CMV replication despite relatively preserved CD4+ T-cell counts suggests that additional interventions are required to improve CMV control in PLWH.

Natural Inhibitor of Human Cytomegalovirus in Human Seminal Plasma

Human cytomegalovirus (HCMV) is the most frequent viral cause of congenital infections that can lead to severe birth defects. Although HCMV is frequently detected in semen and thus is potentially sexually transmitted, the role of semen in HCMV transmission is largely unclear. Here we describe that human seminal plasma (SP; the cell-free supernatant of semen) inhibits HCMV infection. The inhibition of HCMV infection was dose dependent and effective for different cell types, virus strains, and semen donors. This inhibitory effect was specific for HCMV, as herpes simplex virus 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1) infections were enhanced by SP. Mechanistically, SP inhibited infection by interfering with the attachment of virions to cells most likely via an interaction with the trimeric glycoprotein complex gH/gL/gO. Together, our findings suggest that semen contains a factor that potentially limits sexual transmission of HCMV.IMPORTANCE The role of semen in sexual transmission of human cytomegalovirus (HCMV) is currently unclear. This is surprising, as HCMV is frequently detected in this body fluid and infection is of high danger for neonates and pregnant women. In this study, we found that seminal plasma (SP) dose dependently inhibited HCMV infection. The infection inhibition was specific for HCMV, as other viruses, such as human immunodeficiency virus type 1 (HIV-1) and herpes simplex virus 2 (HSV-2), were not inhibited by SP. SP must contain a soluble, heat-resistant factor that limits attachment of HCMV particles to cells, probably by interaction with the trimeric glycoprotein complex gH/gL/gO. This novel virus-host interaction could possibly limit transmission of HCMV via semen during sexual intercourse.

Associations between virologic and immunologic dynamics in blood and in the male genital tract

To determine the influence of asymptomatic genital viral infections on the cellular components of semen and blood, we evaluated the associations between the numbers and activation statuses of CD4+ and CD8+ T lymphocytes in both compartments and the seminal levels of cytomegalovirus (CMV), herpes simplex virus (HSV), and human immunodeficiency virus 1 (HIV). Paired blood and semen samples were collected from 36 HIV-infected antiretroviral-naïve individuals and from 40 HIV-uninfected participants. We performed multiparameter flow cytometry analysis (CD45, CD45RA, CD3, CD4, CD8, and CD38) of seminal and blood cellular components and measured HIV RNA and CMV and HSV DNA levels in seminal and blood plasma by real-time PCR. Compared to HIV-uninfected participants, in the seminal compartment HIV-infected participants had higher levels of CMV (P < 0.05), higher numbers of total CD3+ (P < 0.01) and CD8+ subset (P < 0.01) T lymphocytes, and higher CD4+ and CD8+ T lymphocyte activation (RA-CD38+) (P < 0.01). Seminal CMV levels positively correlated with absolute numbers of CD4+ and CD8+ T cells in semen (P < 0.05) and with the activation status of CD4+ T cells in semen and in blood (P < 0.01). HIV levels in semen (P < 0.05) and blood (P < 0.01) were positively associated with T-cell activation in blood. Activation of CD8+ T cells in blood remained an independent predictor of HIV levels in semen in multivariate analysis. The virologic milieu in the male genital tract strongly influences the recruitment and activation of immune cells in semen and may also modulate T-cell immune activation in blood. These factors likely influence replication dynamics, sexual transmission risk, and disease outcomes for all three viruses.

Preventing sexual transmission of HIV

The risk of human immunodeficiency virus (HIV) transmission during sexual activity is dependent on the infectivity of the HIV-positive individual and the susceptibility of the uninfected partner. HIV is most often transmitted during periods of high HIV load, but factors such as the type of sexual activity and the innate and genetic defenses of the uninfected partner exert a strong influence on the risk of transmission. Certain factors, such as coinfection with other sexually transmitted diseases or the presence of genital lesions in either sexual partner, amplify the risk of transmission that is predicted on the basis of sexual contact alone. In the absence of more-reliable options, such as a vaccine, factors that define HIV infectivity and susceptibility and factors that amplify the risk of HIV transmission, may serve as critical targets for containment of the HIV epidemic.

Oral epithelial cells are susceptible to cell-free and cell-associated HIV-1 infection in vitro

Epithelial cells lining the oral cavity are exposed to HIV-1 through breast-feeding and oral-genital contact. Genital secretions and breast milk of HIV-1-infected subjects contain both cell-free and cell-associated virus. To determine if oral epithelial cells can be infected with HIV-1 we exposed gingival keratinocytes and adenoid epithelial cells to cell-free virus and HIV-1-infected peripheral blood mononuclear cells and monocytes. Using primary isolates we determined that gingival keratinocytes are susceptible to HIV-1 infection via cell-free CD4-independent infection only. R5 but not X4 viral strains were capable of infecting the keratinocytes. Further, infected cells were able to release infectious virus. In addition, primary epithelial cells isolated from adenoids were also susceptible to infection; both cell-free and cell-associated virus infected these cells. These data have potential implications in the transmission of HIV-1 in the oral cavity.

Bacteria in the chronic prostatitis-chronic pelvic pain syndrome: molecular approaches to critical research questions

PURPOSE

There is a pressing need to determine the causes and consequences of, and optimal therapy for the chronic prostatitis-chronic pelvic pain syndrome.

MATERIALS AND METHODS

New data suggest that bacterial infection may be critical in some patients. We examined the rationale for and technical approaches to hypothesis driven studies of bacteria in the chronic prostatitis-chronic pelvic pain syndrome.

RESULTS

The first hypothesis was that patients with the chronic prostatitis-chronic pelvic pain syndrome have prostatic bacteria that distinguish them from controls. In pilot studies patients with inflamed expressed prostatic secretions were more likely to have bacterial DNAs, that is 16S ribosomal DNAs. Current goals are to clone, sequence and compare ribosomal DNAs from patients and controls to determine which bacteria are most specific to the chronic prostatitis-chronic pelvic pain syndrome and which should be targeted in clinical trials. The second hypothesis was that bacterial viability correlates with the severity of the chronic prostatitis-chronic pelvic pain syndrome. Quantitative assays for bacterial elongation factor messenger RNA (tufA messenger RNA) provide tools to correlate bacterial viability with patient characteristics, will provide insights into the potential value of antimicrobial therapy and identify characteristics that distinguish patients most likely to respond. The third hypothesis was that patients with prostatic bacteria have similar bacteria in expressed prostatic secretions or on seminal fluid analysis and, furthermore, these bacteria differ from bacteria in controls. These studies would determine whether expressed prostatic secretions or seminal fluid analysis can be used to identify prostatic bacteria and may result in clinical methods for noninvasive diagnosis of prostatic infection.

CONCLUSIONS

These studies should provide important insights into the causes of the chronic prostatitis-chronic pelvic pain syndrome and may elucidate optimal clinical evaluation and treatment in patients.

Contribution of immune activation to the pathogenesis and transmission of human immunodeficiency virus type 1 infection

The life cycle of human immunodeficiency virus type 1 (HIV-1) is intricately related to the activation state of the host cells supporting viral replication. Although cellular activation is essential to mount an effective host immune response to invading pathogens, paradoxically the marked systemic immune activation that accompanies HIV-1 infection in vivo may play an important role in sustaining phenomenal rates of HIV-1 replication in infected persons. Moreover, by inducing CD4+ cell loss by apoptosis, immune activation may further be central to the increased rate of CD4+ cell turnover and eventual development of CD4+ lymphocytopenia. In addition to HIV-1-induced immune activation, exogenous immune stimuli such as opportunistic infections may further impact the rate of HIV-1 replication systemically or at localized anatomical sites. Such stimuli may also lead to genotypic and phenotypic changes in the virus pool. Together, these various immunological effects on the biology of HIV-1 may potentially enhance disease progression in HIV-infected persons and may ultimately outweigh the beneficial aspects of antiviral immune responses. This may be particularly important for those living in developing countries, where there is little or no access to antiretroviral drugs and where frequent exposure to pathogenic organisms sustains a chronically heightened state of immune activation. Moreover, immune activation associated with sexually transmitted diseases, chorioamnionitis, and mastitis may have important local effects on HIV-1 replication that may increase the risk of sexual or mother-to-child transmission of HIV-1. The aim of this paper is to provide a broad review of the interrelationship between immune activation and the immunopathogenesis, transmission, progression, and treatment of HIV-1 infection in vivo.

Emerging concepts in gastrointestinal aspects of HIV-1 pathogenesis and management

GASTROENTROLOGY 2001;120:607-621

Comparison of assays to detect cytomegalovirus shedding in the semen of HIV-infected men

We sought to determine the optimal assays for cytomegalovirus (CMV) shedding in semen. Over a 2-month period, 149 HIV-1-infected men who have sex with men each provided up to three semen specimens. Specimens were tested for CMV by culture, rapid assay (shell vial) and polymerase chain reaction (PCR). By culture, 30% of seminal plasma and 28% of seminal cell specimens grew CMV. By rapid assay, results were 38 and 33%, respectively. By PCR, 56% of seminal cell specimens demonstrated CMV: 20% in a single semen specimen; 33% in two specimens; and 34% in all three specimens. Overall, 69% of men had CMV detected by PCR in at least one seminal cell specimen. By quantitative PCR, 14% had ten, 14% had 100, 16% had 1000, and 12% had 10000 copies in 6.25 microl of semen analyzed. Adjusting for initial CD4+ cell count, men with CMV shedding demonstrated by PCR at the first visit were approximately four times as likely to shed CMV at a subsequent visit (RR 4.28, CI: 2.30-7.95). CMV shedding was associated with decreased CD4+ cell counts in peripheral blood (P=0.05). It is concluded that the PCR assay provided the greatest sensitivity among the three detection methods.

Multicenter evaluation of methods to quantitate human immunodeficiency virus type 1 RNA in seminal plasma

We have evaluated two commercially available kits (AMPLICOR MONITOR [Roche] and NASBA HIV-1 QT or NucliSens HIV-1 QT [Organon Teknika]) and two noncommercial methods for the accurate quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in seminal plasma. The same panels of coded specimens were tested on four separate occasions. Laboratories using the commercial assays employed silica beads to isolate HIV-1 RNA, which removed inhibitory factors sometimes found in seminal plasma. Sensitivities and specificities, respectively, for each assay were as follows: AMPLICOR MONITOR, 100 and 73%; NASBA HIV-1 QT, 84 and 100%; NucliSens HIV-1 QT, 99 and 98%; and noncommercial assays, 91 and 73%. When results from the laboratory that was inexperienced with the silica bead extraction method were excluded from the analysis, specificity for the Roche assay increased to 100%. The commercial assays demonstrated highly reproducible results, with intra-assay standard deviations (measured in log(10) RNA copies/milliliter of seminal plasma) ranging from 0.11 to 0.32; those of the noncommercial assays ranged from 0.12 to 0.75. Differences in mean estimated HIV-1 RNA concentrations were </=0.67 log(10) and were greater at low viral loads. Suspension matrices that used blood plasma or seminal plasma did not make a difference in recovery of HIV-1 RNA, which suggested that blood plasma specimens can be used as external controls for seminal plasma assays. More variation in the HIV-1 RNA viral loads was observed in the seminal plasma values than in the blood plasma values when paired specimens from HIV-1-infected men were tested. Quantitation of HIV-1 RNA in seminal plasma can be reliably accomplished using two commercially available assays, and may be incorporated into the evaluations of HIV-1 seropositive men enrolled in clinical studies.

Asymptomatic urethritis and detection of HIV-1 RNA in seminal plasma

OBJECTIVE

To define risk factors for detection of HIV-1 RNA in semen in men attending the two largest HIV clinics in the West Midlands.

METHODS

94 HIV-1 seropositive men at any stage of infection donated matched semen and blood samples. 36 subjects (38%) were on no antiretroviral treatment, 12 (13%) were on dual therapy, and 46 (49%) were on three or more drugs. Median CD4 count was 291 cells x 10(6)/l. 87 subjects underwent a urethritis screen (Gram stained urethral smear and culture for gonococcus, and LCR for Chlamydia trachomatis on first pass urine). Quantitative cell free HIV-1 RNA was determined by commercial nucleic acid sequence based assay with a lower detection limit of 800 copies/ml for semen and 400 copies/ml for blood. Independent risk factors for seminal HIV RNA detection were defined by logistic regression.

RESULTS

In univariate analysis, subjects not taking antiretrovirals were 11 times more likely to shed HIV RNA (21/36 (58%) v 6/58 (10%); p < 0.0001). Seven subjects (8%) had urethritis (including one C trachomatis infection). Urethritis was significantly associated with detection of seminal HIV RNA (adjusted OR, 80.2; p = 0.006), as was blood plasma viral load (adj OR, 19.3 per factor 10 increase; p < 0.001) and age (adj OR, 1.16 per 1 year older; p = 0.001). Antiviral treatment status, absolute CD4 and CD8 count, clinical stage, treatment centre, ethnicity, and risk factor were not independent predictors. No subject with undetectable blood viral load had detectable seminal HIV RNA.

CONCLUSION

Asymptomatic urethritis is independently associated with seminal HIV RNA shedding.

Design of a "microbicide" for prevention of sexually transmitted diseases using "inactive" pharmaceutical excipients

The human immunodeficiency virus (HIV-1) pandemic has been driven primarily by the sexual transmission of the virus, and facilitated by prior infections with other sexually transmitted disease (STD) pathogens. Although treatment of these STDs has been proposed as a means to decrease the rate of HIV-1 sexual transmission, preventive measures effective against both HIV-1 and other STD pathogens are expected to have a larger impact. These measures include topically applied mechanical and chemical (i.e. microbicidal) barriers. Microbicides of preference should have a broad specificity against diverse STD pathogens and a well established safety record, considering their repeated use over decades. Here, we report that cellulose acetate phthalate (CAP), an "inactive" pharmaceutical excipient, commonly used in the production of enteric tablets and capsules: (1) has antiviral activity against HIV-1 and several herpesviruses (HSV); and (2) when appropriately formulated, in micronized form, inactivates HIV-1, HSV-1, HSV-2, cytomegalovirus, Neisseria gonorrhoeae, Trichomonas vaginalis, Haemophilus ducreyi and Chlamydia trachomatis but does not affect Lactobacilli, components of the natural vaginal flora contributing to resistance against STDs. Thus, the CAP formulations meet the criteria for preferred microbicides and warrant further evaluation in vivo in humans.

HIV and germinal cells: how close an association?

Whether semen from someone who is HIV-positive can be prepared so that it is safe for insemination is a critical question particularly to couples in which the male is seropositive and the female is seronegative. It is reassuring that some investigators have reported great success in using sperm washing to dramatically reduce HIV levels in the ejaculate. Such reports suggest that if free virus and leukocytes in the seminal plasma are removed, the specimen may be safe for insemination. Whether the virus ever is associated with spermatozoa themselves is not fully understood. In situ hybridization as well as electron microscopic studies have suggested the presence of viral particles but whether these are preparation artifacts or evidence of viable viral DNA is not known. Studies of whether the virus is incorporated into developing spermatozoa or is shed in the reproductive tract will aid in the elucidation of sexual transmission of HIV.

Effects of clinical stage and immunological status on semen analysis results in human immunodeficiency virus type 1-seropositive men

Complete semen analyses including computer-assisted sperm motility and morphology assessments were performed to determine if semen and sperm differed between HIV-seropositive men and fertile controls, or differed with symptoms, or CD4+ peripheral cell count categories. Previous studies included small numbers of men and presented conflicting conclusions. Two hundred and fifty non-vasectomized HIV-seropositive men and 38 fertile controls each provided one semen sample. Non-parameteric statistics were used to analyse both continuous and nominal data. Fertile men had significantly greater semen volume, sperm concentration, percent motility, percent rapid and linear motility and total strictly normal spermatozoa than HIV seropositive men. Neither total number nor subtypes of leukocytes in semen differed between the two groups. Among the HIV seropositive men, significant differences in semen analyses were found between CD4+ cell count, clinical, and AIDS categories. Lower CD4+ cell counts (< 200 mm-3) were associated with significantly lower percent motility, percent normal sperm morphology by strict criteria, significantly more spermatids in semen, and higher percentages of teratozoospermia, oligoasthenoteratozoospermia and leukocytospermia. Healthier men, based on clinical categories, had significantly more normal shaped spermatozoa and fewer had azoospermia, oligoasthenoteratozoospermia or leukocytospermia. Many HIV-seropositive men have normal semen analyses, but as the disease progresses more defects are found, particularly in strict criteria sperm morphology.

3-Hydroxyphthaloyl beta-lactoglobulin. III. Antiviral activity against herpesviruses

The spread of sexually transmitted diseases, including human immunodeficiency virus type 1 (HIV-1) and herpesvirus infections, has continued unabated despite educational efforts spearheaded as a response to the HIV-1 epidemic. This suggests the need for prophylactic measures, including the application of topical antiviral agents. Chemical modification of bovine beta-lactoglobulin (beta-LG), the major protein of whey, by hydroxyphthalic anhydride (3HP) led to the generation of a potent HIV-1 inhibitor (designated 3HP-beta-LG) shown to also have activity against herpes simplex virus types 1 and 2 (HSV-1, HSV-2). This report provides more detailed results concerning the anti-herpesvirus activity of 3HP-beta-LG, indicating that this compound: (i) inhibited infection by human cytomegalovirus (HCMV), which is known to be sexually transmitted; (ii) inactivated the infectivity of both HSV-1 and HSV-2; (iii) inhibited cell-to-cell transmission of HSV-1 and HSV-2; and (iv) bound to HSV-1, HSV-2 and HCMV virus particles and partially inhibited the binding of anti-glycoprotein E (gE) and anti-gC monoclonal antibodies to HSV-1 and HSV-2. The binding of 3HP-beta-LG to the herpesviruses under study was inhibited by aggregated human IgG, suggesting that the respective viral Fc receptor is one of the target sites for 3HP-beta-LG. In agreement with results on inhibition of HIV-1 infection, 3HP-beta-LG appears to be the acid anhydride-modified protein of choice as an antiviral agent against herpesviruses.

Detection of cytomegalovirus in semen from a population of men seeking infertility evaluation

OBJECTIVE

To determine the incidence of cytomegalovirus in the ejaculates of infertile men who were seropositive for IgG antibodies to cytomegalovirus.

DESIGN

Prospective study.

PATIENT(S)

We tested cytomegalovirus infection in the semen of men participating in an IVF-ET program.

MAIN OUTCOME MEASURE(S)

IgG and IgM antibodies to cytomegalovirus were measured in sera. We used polymerase chain reaction (PCR) and cell culture to look for both cytomegalovirus DNA and infectious virus in the semen of 70 men with cytomegalovirus-specific antibodies detected in sera.

RESULT(S)

Of the infertile couples, 13.5% exhibited "mismatching" serology (i.e., detection of IgG antibodies to cytomegalovirus in male serum only and not in female serum) and constituted a potential risk for cytomegalovirus transmission. Cytomegalovrius was identified in the semen of two patients who were positive for IgG antibodies to cytomegalovirus. Cytomegalovirus DNA also was detected in one positive sample after centrifugation through a three-layer Percoll gradient.

CONCLUSION(S)

Human cytomegalovirus was present in the semen from a population of infertile men. Rapid detection can be achieved by molecular techniques such as PCR combined with a hybridization assay. Even though cytomegalovirus was infrequently detected in semen, these data must be considered in determining the risk of transmission and developmental anomalies in infected fetuses.