ABSTRACT
The mechanisms triggering the human immunodeficiency virus type I (HIV-1) to switch the coreceptor usage from CCR5 to CXCR4 during the course of infection are not entirely understood. While low CD4+ T cell counts are associated with CXCR4 usage, a predominance of CXCR4 usage with still high CD4+ T cell counts remains puzzling. Here, we explore the hypothesis that viral adaptation to the human leukocyte antigen (HLA) complex, especially to the HLA class II alleles, contributes to the coreceptor switch. To this end, we sequence the viral gag and env protein with corresponding HLA class I and II alleles of a new cohort of 312 treatment-naive, subtype C, chronically-infected HIV-1 patients from South Africa. To estimate HLA adaptation, we develop a novel computational approach using Bayesian generalized linear mixed models (GLMMs). Our model allows to consider the entire HLA repertoire without restricting the model to pre-learned HLA-polymorphisms. In addition, we correct for phylogenetic relatedness of the viruses within the model itself to account for founder effects. Using our model, we observe that CXCR4-using variants are more adapted than CCR5-using variants (p-value = 1.34e-2). Additionally, adapted CCR5-using variants have a significantly lower predicted false positive rate (FPR) by the geno2pheno[coreceptor] tool compared to the non-adapted CCR5-using variants (p-value = 2.21e-2), where a low FPR is associated with CXCR4 usage. Consequently, estimating HLA adaptation can be an asset in predicting not only coreceptor usage, but also an approaching coreceptor switch in CCR5-using variants. We propose the usage of Bayesian GLMMs for modeling virus-host adaptation in general.
Subject(s)
HIV Infections , HIV-1 , Humans , Receptors, CCR5/genetics , Receptors, CCR5/metabolism , Phylogeny , Bayes Theorem , Receptors, CXCR4/genetics , Receptors, CXCR4/metabolism , Histocompatibility AntigensABSTRACT
Sudden and unexpected death in infancy (SUDI) may be triggered by an external risk or exposure. Intestinal infections with enteric viruses may disrupt the gut and enhance bacterial toxins present in SUDI cases. While diarrhoeal disease deaths have decreased worldwide, approximately half a million deaths still occur in children in Sub- Saharan Africa and South Asia. Furthermore, the role of viral enteropathogens in SUDI cases have not been investigated. The aim of this study was to describe specific viral pathogens in stool samples collected from SUDI cases and age-matched, apparently healthy infants in Cape Town, South Africa. Stool samples were collected from 176 SUDI cases between June 2017 and May 2018. In addition, stool samples were collected from the nappies of 30 age-matched, apparently healthy infants as a control group. Real-time polymerase chain reaction was performed on the stool samples for viral detection. A total of 111 SUDI cases were positive for viruses, with rotavirus (38.6%; 68/176) and norovirus GI and GII (30.0%; 53/176) were prevalent in SUDI cases. Adenovirus Type F was present in only 15.9% (28/176), astrovirus in 9.7% (17/176), and sapovirus in 0.6% (1/176) of cases. In the control samples, norovirus GII was detected most frequently (36.7%; 11/30), followed by rotavirus (33.3%; 10/30), and sapovirus in 6.7% (2/30). While there was no significant association between SUDI cases and enteric viruses, the majority of viruses were significantly associated with the seasons. The study confirms the importance of rotavirus vaccination and describes the significance of norovirus infection in children, post rotavirus vaccine introduction.
Subject(s)
Enterovirus Infections , Norovirus , Rotavirus , Viruses , Child , Infant , Humans , South Africa/epidemiology , Diarrhea/epidemiology , Gastrointestinal Tract , FecesABSTRACT
BACKGROUND: Mucins are large O-linked glycosylated proteins which give mucus their gel-forming properties. There are indications that mucus and mucins in saliva, breast milk and in the cervical plug inhibit the human immunodeficiency virus (HIV-1) in an in vitro assay. Crude mucus gels form continuous layers on the epithelial surfaces of the major internal tracts of the body and protect these epithelial surfaces against aggressive luminal factors such as hydrochloric acid and pepsin proteolysis in the stomach lumen, the movement of hard faecal pellets in the colon at high pressure, the effects of shear against the vaginal epithelium during intercourse and the presence of foreign substances in the respiratory airways. Tumour-associated epitopes on mucins make them suitable as immune-targets on malignant epithelial cells, rendering mucins important as diagnostic and prognostic markers for various diseases, even influencing the design of mucin-based vaccines. Sub-Saharan Africa has the highest prevalence of HIV-AIDS in the world. The main points of viral transmission are via the vaginal epithelium during sexual intercourse and mother-to-child transmission during breast-feeding. There have been many studies showing that several body fluids have components that prevent the transmission of HIV-1 from infected to non-infected persons through various forms of contact. Crude saliva and its purified mucins, MUC5B and MUC7, and the purified mucins from breast milk, MUC1 and MUC4 and pregnancy plug cervical mucus (MUC2, MUC5AC, MUC5B and MUC6), inhibit HIV-1 in an in vitro assay. There are conflicting reports of whether crude breast-milk inhibits HIV-1 in an in vitro assay. However studies with a humanised BLT mouse show that breast-milk does inhibit HIV and that breast-feeding is still advisable even amongst HIV-positive women in under-resourced areas, preferably in conjunction with anti-retroviral treatment. CONCLUSION: These findings raise questions of how such a naturally occurring biological substance such as mucus, with remarkable protective properties of epithelial surfaces against aggressive luminal factors in delicate locations, could be used as a tool in the fight against HIV-AIDS, which has reached epidemic proportions in sub-Saharan Africa.
Subject(s)
Antiviral Agents/metabolism , HIV-1/drug effects , HIV-1/physiology , Mucins/metabolism , Mucus/metabolism , Virus Replication/drug effects , Cervix Uteri/chemistry , Female , Humans , Milk, Human/chemistry , Saliva/chemistryABSTRACT
The occurrence of rotavirus (RV) infection among vaccinated children in high-burden settings poses a threat to further disease burden reduction. Genetically altered viruses have the potential to evade both natural infection and vaccine-induced immune responses, leading to diarrheal diseases among vaccinated children. Studies characterizing RV strains responsible for breakthrough infections in resource-limited countries where RV-associated diarrheal diseases are endemic are limited. We aimed to characterize RV strains detected in fully vaccinated children residing in Zambia using next-generation sequencing. We conducted whole genome sequencing on Illumina MiSeq. Whole genome assembly was performed using Geneious Prime 2023.1.2. A total of 76 diarrheal stool specimens were screened for RV, and 4/76 (5.2%) were RV-positive. Whole genome analysis revealed RVA/Human-wt/ZMB/CIDRZ-RV2088/2020/G1P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2 and RVA/Human-wt/ZMB/CIDRZ-RV2106/2020/G12P[4]-I1-R2-C2-M2-A2-N1-T2-E1-H2 strains were mono and multiple reassortant (exchanged genes in bold) respectively, whilst RVA/Human-wt/ZMB/CIDRZ-RV2150/2020/G12P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1 was a typical Wa-like strain. Comparison of VP7 and VP4 antigenic epitope of breakthrough strains and Rotarix strain revealed several amino acid differences. Variations in amino acids in antigenic epitope suggested they played a role in immune evasion of neutralizing antibodies elicited by vaccination. Findings from this study have the potential to inform national RV vaccination strategies and the design of highly efficacious universal RV vaccines.
ABSTRACT
BACKGROUND: Sub-Saharan Africa is the world's worst HIV-AIDS affected region. More interventions to manage this pandemic are urgently required. Transmission of the virus through an exchange of saliva is rarely known to occur. This project sought to verify statistically previous findings in our laboratory, that crude saliva from uninfected individuals together with its purified mucin components inhibited HIV-1, whilst mucins from infected saliva did not show this inhibition, in an in vitro assay. METHODS: Saliva was extracted in 4 M guanidinium hydrochloride and proteolytic inhibitors at pH 6.5, followed by the isolation of MUC5B and MUC7 by Sepharose 4B gel filtration and further purification of these mucins by density-gradient ultra-centrifugation in caesium chloride. Agarose gel electrophoresis, Western blotting and amino acid compositional analysis determined the size, purity and identity of the mucins. The inhibitory activity of crude saliva and purified MUC5B and MUC7, from HIV negative (n=20) and HIV positive (n=20) donors, was tested by their incubation with subtype C HIV-1 and subsequent infection of peripheral blood mononuclear cells (PBMCs). PCR was done on tandem repeat regions of MUC5B and MUC7 DNA to investigate whether any association existed between gene polymorphism and susceptibility to infection. RESULTS: There was an inter-individual variation in the amounts of MUC5B and MUC7 in saliva. In contrast to previous studies, crude saliva and purified mucins from both HIV negative and HIV positive individuals inhibited the infection of HIV-1 in an in vitro assay. DNA analysis of the tandem repeat regions of MUC5B and MUC7 revealed no difference between groups. CONCLUSIONS: Crude saliva and its mucins, MUC5B and MUC7, from both uninfected controls and HIV positive individuals inhibited HIV-1 in an in vitro assay.
Subject(s)
HIV Infections/immunology , HIV Infections/virology , HIV-1/immunology , Mucins/immunology , Saliva/immunology , Amino Acids/analysis , Blotting, Western , Cells, Cultured , Chromatography, Gel , Electrophoresis, Agar Gel , Humans , Leukocytes, Mononuclear/virology , Mucins/chemistry , Mucins/isolation & purification , South AfricaABSTRACT
HIV-exposed uninfected (HEU) infants have higher infectious morbidity than HIV-unexposed uninfected (HUU) infants. We present the clinical outcomes from a pilot cohort study of 27 HEU and 28 HUU infants. In the absence of infant malnutrition or advanced maternal HIV, HEU infants experienced a 2.74 (0.85-8.78) times greater risk of hospitalization in the first year.
Subject(s)
HIV Infections/epidemiology , Hospitalization/statistics & numerical data , Infectious Disease Transmission, Vertical/statistics & numerical data , Pregnancy Complications, Infectious/epidemiology , Adult , Female , Follow-Up Studies , Humans , Incidence , Infant , Male , Morbidity , Odds Ratio , Pregnancy , Respiratory Tract Infections/epidemiology , Risk Factors , Socioeconomic Factors , South Africa/epidemiologyABSTRACT
CONTEXT: Altered immune responses might contribute to the high morbidity and mortality observed in human immunodeficiency virus (HIV)-exposed uninfected infants. OBJECTIVE: To study the association of maternal HIV infection with maternal- and infant-specific antibody levels to Haemophilus influenzae type b (Hib), pneumococcus, Bordetella pertussis antigens, tetanus toxoid, and hepatitis B surface antigen. DESIGN, SETTING, AND PARTICIPANTS: A community-based cohort study in Khayelitsha, Western Cape Province, South Africa, between March 3, 2009, and April 28, 2010, of 109 HIV-infected and uninfected women and their infants. Serum samples from 104 women and 100 infants were collected at birth and samples from 93 infants were collected at 16 weeks. MAIN OUTCOME MEASURE: Level of specific antibody in mother-infant pairs at delivery and in infants at 16 weeks, determined by enzyme-linked immunosorbent assays. RESULTS: At birth, HIV-exposed uninfected infants (n = 46) had lower levels of specific antibodies than unexposed infants (n = 54) did to Hib (0.37 [interquartile range {IQR}, 0.22-0.67] mg/L vs 1.02 [IQR, 0.34-3.79] mg/L; P < .001), pertussis (16.07 [IQR, 8.87-30.43] Food and Drug Administration [FDA] U/mL vs 36.11 [IQR, 20.41-76.28] FDA U/mL; P < .001), pneumococcus (17.24 [IQR, 11.33-40.25] mg/L vs 31.97 [IQR, 18.58-61.80] mg/L; P = .02), and tetanus (0.08 [IQR, 0.03-0.39] IU/mL vs 0.24 [IQR, 0.08-0.92] IU/mL; P = .006). Compared with HIV-uninfected women (n = 58), HIV-infected women (n = 46) had lower specific antibody levels to Hib (0.67 [IQR, 0.16-1.54] mg/L vs 1.34 [IQR, 0.15-4.82] mg/L; P = .009) and pneumococcus (33.47 [IQR, 4.03-69.43] mg/L vs 50.84 [IQR, 7.40-118.00] mg/L; P = .03); however, no differences were observed for antipertussis or antitetanus antibodies. HIV-exposed uninfected infants (n = 38) compared with HIV-unexposed infants (n = 55) had robust antibody responses following vaccination, with higher antibody responses to pertussis (270.1 [IQR, 84.4-355.0] FDA U/mL vs 91.7 [IQR, 27.9-168.4] FDA U/mL; P = .006) and pneumococcus (47.32 [IQR, 32.56-77.80] mg/L vs 14.77 [IQR, 11.06-41.08] mg/L; P = .001). CONCLUSION: Among South African infants, antenatal HIV exposure was associated with lower specific antibody responses in exposed uninfected infants compared with unexposed infants at birth, but with robust responses following routine vaccination.
Subject(s)
Antibodies, Bacterial/blood , Antibody Formation , HIV Infections/immunology , Immunity, Maternally-Acquired/immunology , Pregnancy Complications, Infectious/immunology , Vaccines/immunology , Case-Control Studies , Cohort Studies , Female , Hepatitis B Surface Antigens/blood , Humans , Infant, Newborn , Male , Maternal-Fetal Exchange , Pregnancy , South Africa , Vaccination , Young AdultABSTRACT
In a resource-constrained African setting, children suspected of being infected with HIV are often screened with rapid antibody tests prior to definitive diagnosis with viral genome detection. It has previously been shown that a rapid antibody assay such as the Capillus HIV-1/HIV-2 test may have a high false-negative rate in infants. In this study CD(4) (+) count and percentage, HIV-1 viral load, antigen-specific reactivity, and age was explored as predictors of negative or low antibody reactivity by this assay. Young age was found to be the only factor associated significantly with low antibody reactivity. This phenomenon appeared to be specific to HIV since no such age association was found for antibody reactivity to tetanus toxoid. Rapid assays only validated in adults should therefore be used with utmost caution in young infants since this may lead to high rates of false-negative results.
Subject(s)
HIV Antibodies/blood , HIV Infections/diagnosis , HIV Infections/immunology , HIV-1/immunology , Mass Screening/methods , Virology/methods , Africa , Age Factors , False Negative Reactions , Female , Humans , Immunoassay , Infant , Male , Sensitivity and SpecificityABSTRACT
BACKGROUND: We have previously shown that MUC5B and MUC7 mucins from saliva of HIV negative individuals inhibit HIV-1 activity by 100% in an in vitro assay. The purpose of this subsequent study was to investigate whether MUC5B and MUC7 from saliva of HIV patients or with full blown AIDS had a similar inhibitory activity against the virus. METHODS: Salivary MUC5B and MUC7 from HIV patients with different CD4 counts (< 200, 200-400 and > 400) were incubated with HIV-1 prior to infection of the human T lymphoblastoid cell line (CEM SS cells). Cells were then cultured and viral replication was measured by a qualitative p24 antigen assay. The size, charge and immunoreactivity of mucins from HIV negative and positive individuals was also analysed by SDS-PAGE, Western blot and ELISA respectively. RESULTS: It was shown that irrespective of their CD4 counts both MUC5B and MUC7 from HIV patients, unlike the MUC5B and MUC7 from HIV negative individuals, did not inhibit HIV-1 activity. Size, charge and immunoreactivity differences between the mucins from HIV negative and positive individuals and among the mucins from HIV patients of different CD4 count was observed by SDS-PAGE, Western blot and ELISA. CONCLUSIONS: Purified salivary mucins from HIV positive patients do not inhibit the AIDS virus in an in vitro assay. Although the reason for the inability of mucins from infected individuals to inhibit the virus is not known, it is likely that there is an alteration of the glycosylation pattern, and therefore of charge of mucin, in HIV positive patients. The ability to inhibit the virus by aggregation by sugar chains is thus diminished.
Subject(s)
HIV Infections/immunology , HIV-1/growth & development , HIV-1/immunology , Mucin-5B/immunology , Mucins/immunology , Salivary Proteins and Peptides/immunology , Blotting, Western , CD4 Lymphocyte Count , Cell Line , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay , Female , HIV Core Protein p24/analysis , Humans , Molecular Weight , Mucin-5B/chemistry , Mucin-5B/isolation & purification , Mucins/chemistry , Mucins/isolation & purification , Salivary Proteins and Peptides/chemistry , Salivary Proteins and Peptides/isolation & purificationABSTRACT
BACKGROUND: The female reproductive tract is amongst the main routes for Human Immunodeficiency Virus (HIV) transmission. Cervical mucus however is known to protect the female reproductive tract from bacterial invasion and fluid loss and regulates and facilitates sperm transport to the upper reproductive tract. The purpose of this study was to purify and characterize pregnancy plug mucins and determine their anti-HIV-1 activity in an HIV inhibition assay. METHODS: Pregnancy plug mucins were purified by caesium chloride density-gradient ultra-centrifugation and characterized by Western blotting analysis. The anti-HIV-1 activities of the crude pregnancy plug mucus and purified pregnancy plug mucins was determined by incubating them with HIV-1 prior to infection of the human T lymphoblastoid cell line (CEM SS cells). RESULTS: The pregnancy plug mucus had MUC1, MUC2, MUC5AC and MUC5B. The HIV inhibition assay revealed that while the purified pregnancy plug mucins inhibit HIV-1 activity by approximately 97.5%, the crude pregnancy plug mucus failed to inhibit HIV-1 activity. CONCLUSION: Although it is not clear why the crude sample did not inhibit HIV-1 activity, it may be that the amount of mucins in the crude pregnancy plug mucus (which contains water, mucins, lipids, nucleic acids, lactoferrin, lysozyme, immunoglobulins and ions), is insufficient to cause viral inhibition or aggregation.
Subject(s)
Cervix Mucus/immunology , HIV-1/drug effects , Mucins/immunology , Blotting, Western , Cell Line, Tumor , Cervix Mucus/chemistry , Electrophoresis, Polyacrylamide Gel , Female , HIV-1/physiology , Humans , Mucins/chemistry , Mucins/isolation & purification , Pregnancy , Virus Replication/drug effectsABSTRACT
PURPOSE: This study aimed to determine the prevalence of human respiratory syncytial virus (HRSV) acute respiratory infection (ARI) in children under the age of 5 years at the Provincial General Hospital of Bukavu (PGHB), and to analyse factors associated with the risk of ARI being diagnosed as lower respiratory tract infection (LRTI). METHODOLOGY: A total of 146 children under 5 years visiting the PGHB for ARI between August and December 2016 were recruited, and socio-demographic information, clinical data and nasopharyngeal swabs were collected. The samples were analysed by a multiplex reverse transcriptase polymerase chain reaction targeting 15 different viruses. RESULTS: Of 146 samples collected, 84 (57.5â%) displayed a positive result of at least one of the 15 viruses. The overall prevalence of HRSV was 21.2â%. HRSV A (30, 20.5â%) was the virus the most detected, followed by HRV (24, 16.4â%), PIV3 (20, 16.6) and ADV (7, 4.79â%). The other viruses were detected in three or fewer cases. There were only 11 (7.5â%) cases of co-infection. HRSV infection, malnutrition, younger age, rural settings, low income and mother illiteracy were associated with the risk of ARI being diagnosed as LRTI in bivariate analyses but, after adjusting for the confounding factors, only HRSV infection and younger age were independently associated with LRTI. CONCLUSION: The prevalence of HRSV is high among children visiting the PGHB for ARI. HRSV infection and lower age are independently associated with the risk of ARI being diagnosed as LRTI.
Subject(s)
Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/physiology , Respiratory Tract Infections/virology , Virus Diseases/virology , Virus Physiological Phenomena , Child, Preschool , Coinfection/epidemiology , Coinfection/virology , Democratic Republic of the Congo/epidemiology , Female , Hospitals, General/statistics & numerical data , Humans , Infant , Male , Prevalence , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus, Human/classification , Respiratory Syncytial Virus, Human/genetics , Respiratory Syncytial Virus, Human/isolation & purification , Respiratory Tract Infections/epidemiology , Virus Diseases/epidemiology , Viruses/classification , Viruses/genetics , Viruses/isolation & purificationABSTRACT
BACKGROUND: Despite the continuous shedding of HIV infected blood into the oral cavity and the detectable presence of the AIDS virus at a high frequency, human saliva is reported to inhibit oral transmission of HIV through kissing, dental treatment, biting, and aerosolization. The purpose of this study was to purify salivary MUC5B and MUC7 mucins from crude saliva and determine their anti-HIV-1 activities. METHODS: Following Sepharose CL-4B column chromatography and caesium chloride isopycnic density-gradient ultra-centrifugation, the purity and identity of the mucins was determined by SDS-PAGE and Western blotting analysis respectively. Subsequently an HIV-1 inhibition assay was carried out to determine the anti-HIV-1 activity of the crude saliva and purified salivary mucins by incubating them with subtype D HIV-1 prior to infection of the CD4+ CEM SS cells. RESULTS: Western blotting analysis confirmed that the mucin in the void volume is MUC5B and the mucin in the included volume is MUC7. The HIV inhibition assay revealed that both the crude saliva and salivary MUC5B and MUC7 mucins inhibited HIV-1 activity by 100%. CONCLUSION: Although the mechanism of action is not clear the carbohydrate moieties of the salivary mucins may trap or aggregate the virus and prevent host cell entry.
Subject(s)
Anti-HIV Agents/pharmacology , HIV-1/drug effects , Mucins/pharmacology , Saliva/physiology , Amino Acids/analysis , Blotting, Western , Chromatography, Gel , Electrophoresis, Polyacrylamide Gel , HIV-1/classification , HIV-1/physiology , Humans , Mucin-5B , Mucins/analysis , Mucins/isolation & purification , Saliva/chemistry , Salivary Proteins and PeptidesABSTRACT
BACKGROUND: Bacille Calmette-Guérin (BCG) is routinely given at birth in tuberculosis-endemic settings due to its protective effect against disseminated tuberculosis in infants. BCG is however contraindicated in HIV-infected infants. We investigated whether delaying BCG vaccination to 14 weeks of age affected vaccine-induced antibody responses to Haemophilus influenzae type b (Hib)-conjugate, pertussis, tetanus and Hepatitis B (HBV) vaccines, in HIV-exposed uninfected (HEU) and -unexposed uninfected (HUU) infants. METHODS: Infants were randomized to receive BCG at birth or at 14 weeks of age. Blood was taken at 14, 24, and 52 weeks of age and analyzed for Hib, pertussis, tetanus and HBV specific antibodies. RESULTS: BCG was given either at birth (106 infants, 51 HEU) or at 14 weeks of age (74 infants, 50 HEU). The timing of BCG vaccination did not influence the antibody response to any antigen studied. However, in a non-randomized comparison, HEU infants had higher Hib antibody concentrations at weeks 14 and 24 (p=0.001 and <0.001, respectively) and pertussis at week 24 (p=0.003). Conversely, HEU infants had lower antibody concentrations to HBV at 14 and 52 weeks (p=0.032 and p=0.031) with no differences in tetanus titres. CONCLUSIONS: HIV exposure, but not the timing of BCG vaccination, was associated with antibody concentrations to Hib, pertussis, HBV and tetanus primary immunization. CLINICAL TRIAL REGISTRATION: DOH-27-1106-1520.
Subject(s)
BCG Vaccine/administration & dosage , Diphtheria-Tetanus-Pertussis Vaccine/therapeutic use , HIV Infections , Haemophilus Vaccines/therapeutic use , Immunization Schedule , Poliovirus Vaccine, Oral/therapeutic use , Tetanus Toxoid/therapeutic use , Antibodies, Bacterial/blood , Antibodies, Viral/blood , Antibody Formation , BCG Vaccine/therapeutic use , Female , Humans , Infant , Infant, Newborn , Infectious Disease Transmission, Vertical , Male , Pregnancy , Single-Blind Method , South Africa , Time FactorsABSTRACT
Enveloped animal viruses such as human immunodeficiency virus (HIV), hepatitis B virus, hepatitis C virus, human papillomavirus, Marburg, and influenza are major public health concerns around the world. The prohibitive cost of antiretroviral (ARV) drugs for most HIV-infected patients in sub-Saharan Africa and the serious side effects in those who have access to ARV drugs make a compelling case for the study of complementary and alternative therapies. Such therapies should have scientifically proved antiviral activity and minimal toxic effects. A plant extract, Secomet-V, with an anecdotal indication in humans for promise as an anti-HIV treatment, was investigated. Using a previously described attenuated vaccinia virus vGK5, we established the antiviral activity of Secomet-V. Chemical analysis showed that it has an acidic pH, nontoxic traces of iron (<10 ppm), and almost undetectable levels of arsenic (<1.0 ppm). The color varies from colorless to pale yellow to dark brown. The active agent is heat stable at least up to sterilizing temperature of 121 degrees C. The crude plant extract is a mixture of several small molecules separable by high-pressure liquid chromatography. The HIV viral loads were significantly reduced over several months in a few patients monitored after treatment with Secomet-V. Secomet-V was also found to have antiviral activity against the SARS virus but not against the West Nile virus. Secomet-V, therefore, is a broad-spectrum antiviral, which possibly works by neutralizing viral infectivity, resulting in the prevention of viral attachment.
Subject(s)
Anti-HIV Agents/therapeutic use , HIV/drug effects , Plant Extracts/toxicity , Poxviridae/drug effects , Severe acute respiratory syndrome-related coronavirus/drug effects , Trifolium , Viral Proteins/toxicity , Cell Line , Humans , Phytotherapy , Poxviridae/growth & developmentABSTRACT
BACKGROUND: Sudden unexpected death in infancy is one of the main contributory factors to high infant mortality rates world-wide. Several risk factors, including viral infection, have been implicated in SUDI cases, but no single factor has been confirmed as the main cause of death. At the Tygerberg Medico-legal Laboratory, Cape Town, South Africa, investigation of lung tissue for viral infection forms part of an institutional protocol for the examination of cases of sudden unexpected death in infancy. METHODS: Lung tissue from 82 cases of sudden unexpected death in infancy was collected over a 10 month period. Routine shell vial cultures and histological examination of the tissue were performed according to the standard institutional protocol on fresh and formalin-fixed tissue, respectively. In addition, real-time polymerase chain reactions and immunohistochemical staining for adenovirus, cytomegalovirus and respiratory syncytial virus were done on fresh and formalin-fixed lung tissue, respectively. RESULTS: Huge variation was found in the number of positive cases confirmed by shell vial culture, real-time polymerase chain reaction and immunohistochemistry (0, 2 and 0 for adenovirus; 3, 29 and 2 for cytomegalovirus; and 0, 0 and 4 for respiratory syncytial virus, respectively). CONCLUSIONS: In the absence of a National Protocol for investigation of sudden unexpected death in infancy, we conclude that the selection of viruses and routine diagnostic technique included in the institutional investigation protocol might be suboptimal and should be re-evaluated.
Subject(s)
Lung/pathology , Lung/virology , Sudden Infant Death/epidemiology , Adenoviridae/genetics , Adenoviridae/isolation & purification , Cytomegalovirus/genetics , Cytomegalovirus/isolation & purification , Female , Forensic Pathology , Humans , Immunohistochemistry , Infant , Male , Medical Audit , Real-Time Polymerase Chain Reaction , Respiratory Syncytial Viruses/genetics , Respiratory Syncytial Viruses/isolation & purification , Retrospective Studies , South Africa/epidemiologyABSTRACT
Currently in South Africa research into sudden unexpected death in infancy (SUDI) is limited. The causes of sudden infant death syndrome (SIDS) remain obscure despite full medico-legal investigations inclusive of autopsy, scene visit and ancillary studies. Viral infections play an important role as a multitude of respiratory viruses have been detected in autopsy specimens and are implicated in these deaths. The specific contribution of viruses in the events preceding SIDS still warrants deciphering. Infancy is characterised by marked vulnerability to infections due to immaturities of the immune system that may only resolve by the age of 24 months. Routine viral screening of all SUDI cases at Tygerberg Forensic Pathology Service (FPS) Mortuary in Cape Town focuses on only a portion of respiratory viruses from lung and liver tissue. This review highlights important virological and immunological aspects regarding investigations into the infectious nature of SUDI, including the lack of national standardised guidelines for appropriate specimen collection at autopsy and subsequent laboratory analysis.
Subject(s)
Sudden Infant Death/immunology , Humans , Immune System/physiology , Infant , Inflammation/immunology , Respiratory Tract Infections/immunology , Respiratory Tract Infections/microbiology , Respiratory Tract Infections/virologyABSTRACT
BACKGROUND: The HIV-AIDS pandemic is prevalent in sub-Saharan Africa. Breastfeeding is a risk factor, with transmission from mother to child being as high as 40%. OBJECTIVES: To determine the antiviral activity of crude breast milk and its purified mucins MUC1 and MUC4 against HIV-1 in patients who were HIV positive compared to those who were not. METHODS: Twenty-one human milk samples were taken from both groups. Breast milk mucins were purified by density-gradient ultracentrifugation in caesium chloride and analyzed by SDS-PAGE, Western blotting and amino acid content. The inhibition of the virus by crude milk and purified mucin was assayed by an in vitro HIV-1 p24 assay. RESULTS: SDS-PAGE for purified mucin showed several high-molecular-weight bands for the HIV-negative group and prominently stained single bands on the stacking gel with faintly periodic acid Schiff-positive glycoprotein bands observed in some cases in the running gel for the HIV-positive mucins. Western blot analysis identified the mucins in both groups to be MUC1 and MUC4. Both mucins showed more intensity on Western blotting for the HIV-positive group. There was no difference in the content of serine, threonine and proline of purified mucins for both groups. HIV-1 was not inhibited by crude breast milk from normal (13/14 samples) and infected individuals (19/19 samples). Fifteen of 20 and 16/18 samples of purified mucin from the uninfected and HIV-positive groups, respectively, inhibited the virus. CONCLUSIONS: Crude breast milk does not inhibit HIV-1, whilst purified mucins do in an in vitro assay.
Subject(s)
Anti-HIV Agents/pharmacology , HIV-1/drug effects , Milk, Human/chemistry , Mucin-1/pharmacology , Mucin-4/pharmacology , Anti-HIV Agents/isolation & purification , Cells, Cultured , Female , HIV Core Protein p24/metabolism , HIV-1/growth & development , HIV-1/metabolism , Humans , Leukocytes, Mononuclear/virology , Mucin-1/isolation & purification , Mucin-4/isolation & purification , Virus Replication/drug effectsABSTRACT
BACKGROUND: Early in life, HIV-exposed uninfected (HEU) infants are at an increased risk of morbidity and mortality from infectious disease compared with HIV-unexposed (UE) infants. To improve our understanding of the mechanisms underlying their increased risk, we contrasted innate immune development between HEU and UE infants in a developing world setting, where early life infectious disease risk is exceptionally high. METHODS: A prospective longitudinal cohort of HEU and UE newborns was established, and the most detailed characterization to date of HEU infant immune development was performed. Single-cell cytokine production was analyzed by flow cytometry after stimulation of whole blood with pathogen-associated molecular patterns (PAMPs). RESULTS: Monocyte, classical dendritic cell, and plasmacytoid dendritic cell composition was similar between HEU and UE infants throughout the first year of life. However, HEU mononuclear cells mounted an enhanced pro-inflammatory response to PAMP stimulation, both in quantity of cytokine produced per cell and in proportion of responder cells. Significant differences in cytokine production were detected on the single-cell level in a PAMP-specific pattern, but only at 2 and 6 weeks of age; all differences normalized by 12 months of age. CONCLUSIONS: This time course of innate immune deviation early in life corresponds to the clinical window of vulnerability to infections in HEU infants and may be at least partially responsible for their increased morbidity and mortality from infectious disease.
Subject(s)
Cytokines/metabolism , HIV Infections/immunology , HIV Seronegativity/immunology , Immunity, Innate/immunology , Infant, Newborn/immunology , Infectious Disease Transmission, Vertical , Pregnancy Complications/immunology , Dendritic Cells/immunology , Female , HIV Infections/transmission , Humans , Longitudinal Studies , Male , Monocytes/immunology , Pregnancy , Pregnancy Complications/virology , Prospective Studies , South AfricaABSTRACT
The effective role of antiretroviral (ARV) therapy in the regulation of CD4 T cell subset distribution, coreceptor expression, and activation status in individuals with chronic HIV also presenting with active pulmonary TB is not clearly understood. A cross-sectional analysis was performed on a total of 137 South African individuals. CCR5, CXCR4, and CD38 expression of CD4 T cell subsets in HIV-infected individuals with and without active pulmonary tuberculosis (TB) disease, pre- and post-ARV therapy, were determined by flow cytometry. In treatment-naive patients, CD4 T cells showed elevated surface expression of CCR5 and CD38 in TB/HIV coinfection as compared to HIV infection alone despite the overall percentage of CD4 T cells expressing CCR5 being reduced. Total CD38+ CD4 T cells were not significantly increased in either group; however, mean CD38 fluorescence was significantly higher in the context of TB infection. HIV/TB-coinfected individuals also displayed an increased percentage of activated (CD38+) CCR5+ CD4 T cells as compared to HIV patients alone. The naive CD4 T cell subset was depleted similarly in both HIV and HIV/TB groups. Only the HIV treatment group and not the TB-coinfected treatment group showed significantly decreased activated CCR5+ CD4 T cells, an increased percentage of naive T cells, and a decreased percentage of antigen-experienced T cells. This study highlighted an association of TB disease with immune activation, particularly of the CCR5+ CD4 T cell subset in HIV infection and the differential impact of ARV treatment. Further studies are needed to understand how TB coinfection confounds normal responses to ARV.
Subject(s)
Anti-HIV Agents/therapeutic use , CD4-Positive T-Lymphocytes/immunology , HIV Infections/complications , Receptors, CCR5/immunology , Tuberculosis, Pulmonary/complications , ADP-ribosyl Cyclase 1/drug effects , ADP-ribosyl Cyclase 1/immunology , Adult , Aged , CD4-Positive T-Lymphocytes/drug effects , Coinfection/immunology , Cross-Sectional Studies , Female , HIV Infections/drug therapy , HIV Infections/immunology , Humans , Lymphocyte Subsets/drug effects , Lymphocyte Subsets/immunology , Male , Middle Aged , Receptors, CCR5/drug effects , Receptors, CXCR4/drug effects , Receptors, CXCR4/immunology , Tuberculosis, Pulmonary/immunology , Young AdultABSTRACT
HIV-exposed but uninfected (HEU) infants born to HIV-infected mothers from areas in the world with a high burden of infectious disease suffer higher infectious morbidity and mortality than their HIV unexposed uninfected (HUU) peers. Vaccination provides protection from infection. The possibility exists that altered response to vaccination contributes to the higher rate of infection in HEU than in HUU infants. While short-term, cross-sectional studies support this notion, it is unclear whether or not HEU infants develop long-term protective immune responses following the WHO extended program on immunization (EPI). Vaccine-specific antibody responses were compared between HEU and HUU infants from 2 weeks until 2 years of age in a longitudinal South African cohort. Total IgG and antibodies specific for Bordetella pertussis, Haemophilus influenzae type b (Hib), tetanus toxoid, hepatitis B virus (HepB), and measles virus were measured at multiple time points throughout the first 2 years of life. Prevaccine antibodies (maternal antibodies passively acquired) specific for tetanus were lower in HEU than in HUU infants, while prevaccine antibodies to HepB were higher in HEU than in HUU infants. Both groups responded similarly to tetanus, Hib, and HepB vaccination. HEU demonstrated stronger pertussis vaccine responses, developing protective titers 1 year earlier than HUU patients, and maintained higher anti-tetanus titers at 24 months of age. Vaccine-induced antibodies to measles virus were similar in both groups at all time points. Our results suggest that the current EPI vaccination program as practiced in South Africa leads to the development of vaccine-specific antibody responses that are equivalent in HEU and HUU infants. However, our data also suggest that a large fraction of both HEU and HUU South African infants have antibody titers for several infectious threats that remain below the level of protection for much of their first 2 years of life.