Community cervical cancer screening and precancer risk in women living with HIV in Jos Nigeria.

BACKGROUND: High HIV prevalence, and lack of organized screening for the indigent population receiving care and treatment within HIV clinics in low-resource settings increases cervical cancer incidence. We sought to determine predictors of cervical precancer in women living with HIV and receiving cervical cancer screening in Jos, Nigeria. METHODS: A cross-sectional study of women living with HIV and receiving care and treatment in adult HIV/AIDS clinics in Jos-Metropolis, Nigeria between June 2020 and April 2023. Ethical approvals were obtained from the ethics committee in Jos, Nigeria and Northwestern University IRB, USA. Informed consent was obtained from eligible participants, and data on socio-demographics, cancer risk factors, and cytology reports were collected. The outcome variables were cervical precancer lesions. The independent variables were prior Pap smear status, socio-demographics, income, educational, and other reproductive health factors. Descriptive statistics was done to obtain means ± sd, frequencies, and percentages for the variables. Univariate and bivariate analyses were done to determine predictors of cervical dysplasia. Analyses were performed using R software. RESULTS: Of 957 women screened, 570 were living with HIV and 566 women had cytology report and were included in the final analysis. The mean age was 45.08 ± 8.89 years and 81.6% had no prior evidence of Pap test (under-screened). Prevalence of cervical dysplasia was 24% (mild and severe dysplasia were 12.9% and 11.1%, respectively). Age above 45 years (aOR = 3.48, p = 0.009), postmenopausal status (aOR = 7.69, p = 0.000), and women with no history of prior IUCD use (aOR = 5.94, p = 0.0001), were predictors for severe dysplasia. Women who had history of STI (aOR = 0.17, p = 0.000), prior use of IUCD (aOR = 0.32, p = 0.004), prior use of condom (aOR = 2.50, p = 0.003) and had co-morbidities (aOR = 0.46, p = 0.009) were more likely to have had a Pap test in the past. CONCLUSIONS: The majority of indigent women receiving care at HIV clinics had their first Pap test screening, and lack of organized screening among older and post-menopausal women with HIV, puts women at a higher risk of developing severe cervical precancer lesions.

Potent dengue virus neutralization by a therapeutic antibody with low monovalent affinity requires bivalent engagement.

We recently described our most potently neutralizing monoclonal antibody, E106, which protected against lethal Dengue virus type 1 (DENV-1) infection in mice. To further understand its functional properties, we determined the crystal structure of E106 Fab in complex with domain III (DIII) of DENV-1 envelope (E) protein to 2.45 Šresolution. Analysis of the complex revealed a small antibody-antigen interface with the epitope on DIII composed of nine residues along the lateral ridge and A-strand regions. Despite strong virus neutralizing activity of E106 IgG at picomolar concentrations, E106 Fab exhibited a ∼20,000-fold decrease in virus neutralization and bound isolated DIII, E, or viral particles with only a micromolar monovalent affinity. In comparison, E106 IgG bound DENV-1 virions with nanomolar avidity. The E106 epitope appears readily accessible on virions, as neutralization was largely temperature-independent. Collectively, our data suggest that E106 neutralizes DENV-1 infection through bivalent engagement of adjacent DIII subunits on a single virion. The isolation of anti-flavivirus antibodies that require bivalent binding to inhibit infection efficiently may be a rare event due to the unique icosahedral arrangement of envelope proteins on the virion surface.

Atomic-level functional model of dengue virus Envelope protein infectivity.

A number of structures have been solved for the Envelope (E) protein from dengue virus and closely related flaviviruses, providing detailed pictures of the conformational states of the protein at different stages of infectivity. However, the key functional residues responsible for mediating the dynamic changes between these structures remain largely unknown. Using a comprehensive library of functional point mutations covering all 390 residues of the dengue virus E protein ectodomain, we identified residues that are critical for virus infectivity, but that do not affect E protein expression, folding, virion assembly, or budding. The locations and atomic interactions of these critical residues within different structures representing distinct fusogenic conformations help to explain how E protein (i) regulates fusion-loop exposure by shielding, tethering, and triggering its release; (ii) enables hinge movements between E domain interfaces during triggered structural transformations; and (iii) drives membrane fusion through late-stage zipper contacts with stem. These results provide structural targets for drug and vaccine development and integrate the findings from structural studies and isolated mutagenesis efforts into a cohesive model that explains how specific residues in this class II viral fusion protein enable virus infectivity.

Epidemiology and Survival outcomes of HIV-associated cervical cancer in Nigeria.

Introduction: Invasive cervical cancer (ICC) is an HIV-associated cancer that is preventable and precancerous stages including early ICC stages could be detected through screening offering opportunities for treatment and cure. The high incidence in women living with HIV and late presentation often at advanced stages of ICC with limited treatment facilities often result in early mortality. We sought to compare the epidemiologic characteristics and survival differences in HIV status of ICC patients in Nigeria. Methods: We conducted a cohort study at two federal academic hospital-based research sites in Jos University Teaching Hospital, and Lagos University Teaching Hospital Nigeria, between March 2018 and September 2022. We enrolled women with histologically confirmed ICC with known HIV status, and FIGO staging as part of the United States of America's National Institutes of Health/National Cancer Institute funded project titled 'Epigenomic Biomarkers of HIV-Associated Cancers in Nigeria'. The primary outcome was all-cause mortality with assessment of overall survival (OS) and time to death after ICC diagnosis. OS distribution was estimated using the method of Kaplan-Meier and compared between groups using the log-rank test. Results: A total of 239 women with confirmed ICC were enrolled and included in this analysis, of whom 192 (80.3%) were HIV-negative (HIV-/ICC+), and 47 (19.7%) were HIV-positive (HIV+/ICC+). The HIV+/ICC) patients were younger with median age 46 (IQR: 40-51) years compared to 57 (IQR: 45-66) among HIV-/ICC+) (P<0.001. Squamous cell carcinoma was the commonest histopathologic variant in 80.4% of ICC diagnosis, moderately differentiated tumor grade in 68.1% in both groups. HIV+/ICC+ diagnosis was at FIGO advanced stages in 64.9% compared to 47.9% in HIV-/ICC+. The HIV-/ICC+ women had better OS compared to HIV+/ICC+ participants (p=0.018), with 12-month OS 84.1% (95%CI: 75% - 90%) and 67.6% (95%CI: 42%-84%) respectively. Conclusion: ICC is diagnosed at a relatively young age in women living with HIV, with a significantly lower overall survival probability compared to women without HIV. The trend of presentation and diagnosis at advanced stages in women living with HIV could partly explain the differences in overall survival.

Developability profiling of a panel of Fc engineered SARS-CoV-2 neutralizing antibodies.

To combat the COVID-19 pandemic, potential therapies have been developed and moved into clinical trials at an unprecedented pace. Some of the most promising therapies are neutralizing antibodies against SARS-CoV-2. In order to maximize the therapeutic effectiveness of such neutralizing antibodies, Fc engineering to modulate effector functions and to extend half-life is desirable. However, it is critical that Fc engineering does not negatively impact the developability properties of the antibodies, as these properties play a key role in ensuring rapid development, successful manufacturing, and improved overall chances of clinical success. In this study, we describe the biophysical characterization of a panel of Fc engineered ("TM-YTE") SARS-CoV-2 neutralizing antibodies, the same Fc modifications as those found in AstraZeneca's Evusheld (AZD7442; tixagevimab and cilgavimab), in which the TM modification (L234F/L235E/P331S) reduce binding to FcγR and C1q and the YTE modification (M252Y/S254T/T256E) extends serum half-life. We have previously shown that combining both the TM and YTE Fc modifications can reduce the thermal stability of the CH2 domain and possibly lead to developability challenges. Here we show, using a diverse panel of TM-YTE SARS-CoV-2 neutralizing antibodies, that despite lowering the thermal stability of the Fc CH2 domain, the TM-YTE platform does not have any inherent developability liabilities and shows an in vivo pharmacokinetic profile in human FcRn transgenic mice similar to the well-characterized YTE platform. The TM-YTE is therefore a developable, effector function reduced, half-life extended antibody platform.

Epidemiology and survival outcomes of HIV-associated cervical cancer in Nigeria.

INTRODUCTION: Invasive cervical cancer (ICC) is an HIV-associated cancer that is preventable and precancerous stages including early ICC stages could be detected through screening offering opportunities for treatment and cure. The high incidence in women living with HIV and late presentation often at advanced stages of ICC with limited treatment facilities often result in early mortality. We sought to compare the epidemiologic characteristics and survival differences in HIV status of ICC patients in Nigeria. METHODS: We conducted a cohort study at two federal academic hospital-based research sites in Jos University Teaching Hospital, and Lagos University Teaching Hospital Nigeria, between March 2018 and September 2022. We enrolled women with histologically confirmed ICC with known HIV status, and FIGO staging as part of the United States of America's National Institutes of Health/National Cancer Institute funded project titled 'Epigenomic Biomarkers of HIV-Associated Cancers in Nigeria'. The primary outcome was all-cause mortality with assessment of overall survival (OS) and time to death after ICC diagnosis. OS distribution was estimated using the method of Kaplan-Meier and compared between groups using the log-rank test. RESULTS: A total of 239 women with confirmed ICC were enrolled and included in this analysis, of whom 192 (80.3%) were HIV-negative (HIV-/ICC +), and 47 (19.7%) were HIV-positive (HIV +/ICC +). The HIV +/ICC + patients were younger with median age 46 (IQR: 40-51) years compared to 57 (IQR: 45-66) among HIV-/ICC + (P < 0.001). Squamous cell carcinoma was the commonest histopathologic variant in 80.4% of ICC diagnosis, moderately differentiated tumor grade in 68.1% in both groups. HIV +/ICC + diagnosis was at FIGO advanced stages in 64.9% compared to 47.9% in HIV-/ICC +. The HIV-/ICC + women had better OS compared to HIV +/ICC + participants (p = 0.018), with 12-month OS 84.1% (95%CI 75-90%) and 67.6% (95%CI 42-84%) respectively. CONCLUSION: ICC is diagnosed at a relatively young age in women living with HIV, with a significantly lower overall survival probability compared to women without HIV. The trend of presentation and diagnosis at advanced stages in women living with HIV could partly explain the differences in overall survival.

Robust vaccine-elicited cellular immune responses in breast milk following systemic simian immunodeficiency virus DNA prime and live virus vector boost vaccination of lactating rhesus monkeys.

Breast milk transmission of HIV remains an important mode of infant HIV acquisition. Enhancement of mucosal HIV-specific immune responses in milk of HIV-infected mothers through vaccination may reduce milk virus load or protect against virus transmission in the infant gastrointestinal tract. However, the ability of HIV/SIV strategies to induce virus-specific immune responses in milk has not been studied. In this study, five uninfected, hormone-induced lactating, Mamu A*01(+) female rhesus monkey were systemically primed and boosted with rDNA and the attenuated poxvirus vector, NYVAC, containing the SIVmac239 gag-pol and envelope genes. The monkeys were boosted a second time with a recombinant Adenovirus serotype 5 vector containing matching immunogens. The vaccine-elicited immunodominant epitope-specific CD8(+) T lymphocyte response in milk was of similar or greater magnitude than that in blood and the vaginal tract but higher than that in the colon. Furthermore, the vaccine-elicited SIV Gag-specific CD4(+) and CD8(+) T lymphocyte polyfunctional cytokine responses were more robust in milk than in blood after each virus vector boost. Finally, SIV envelope-specific IgG responses were detected in milk of all monkeys after vaccination, whereas an SIV envelope-specific IgA response was only detected in one vaccinated monkey. Importantly, only limited and transient increases in the proportion of activated or CCR5-expressing CD4(+) T lymphocytes in milk occurred after vaccination. Therefore, systemic DNA prime and virus vector boost of lactating rhesus monkeys elicits potent virus-specific cellular and humoral immune responses in milk and may warrant further investigation as a strategy to impede breast milk transmission of HIV.

CNS TB-IRIS Following Cessation of Adalimumab in an Adolescent With Crohn's Disease.

Immune reconstitution inflammatory syndrome to tuberculosis (TB-IRIS) is an inflammatory response to M. tuberculosis infection that arises following restoration of the immune system and is increasingly recognized as a risk in patients treated with tumor necrosis factor α inhibitors who develop active tuberculosis infection. We present the case of a 19-year-old man treated with adalimumab for Crohn's disease who presented with disseminated miliary tuberculosis. His treatment course was complicated by central nervous system TB-IRIS following cessation of his immunosuppression. We review the presentation and differential diagnosis of TB-IRIS, as well as risk factors for developing IRIS and the treatment of IRIS in this population.

Using Evidence-Based Pedagogical Approaches to Pivot from In-Person to Online Training in a D43 Program during the COVID-19 Pandemic.

The COVID-19 pandemic caused significant disruption to medical education globally. Fogarty International Center (FIC) training programs, designed to strengthen research capacity in low- and middle-income countries (LMICs), through partnerships between United States and LMIC institutions were particularly vulnerable to COVID-19 disruptions. We adapted short-term training for our FIC HIV Patient-Centered Outcomes Research program in Tanzania to the virtual environment using synchronous, asynchronous, and blended approaches and a variety of teaching pedagogies. We evaluated the acceptability and effectiveness of the new trainings among trainees and facilitators using a mixed-methods approach. Ninety percent of trainees and Muhimbili University of Health and Allied Sciences (MUHAS) facilitators agreed that the virtual training methods used were effective. Trainees reported high levels of satisfaction with the technology, group work, and relevance to their research. More than 50% of trainees and MUHAS facilitators agreed that learning in the virtual environment was as effective as, or more effective than, traditional in-person learning. However, they desired more interaction, opportunities to ask U.S. facilitators questions, and choices about topics for online versus in-person trainings. Two-thirds of U.S. facilitators agreed that the virtual delivery method was an effective way for participants to learn the material, although they also rated interaction less favorably. Virtual training incorporating pedagogical best practices of blended learning and traditional teaching online was a feasible, acceptable, and effective way of conducting research training to junior scientists during COVID-19. Virtual learning could become an integral part of post-pandemic training with some adaptation to improve interactions.

A Bayesian Statistical Approach to Continuous Qualification of a Bioassay.

A validated bioassay is used to measure the potency of commercial lots, and as such, must be accurate, precise, and fit for its intended purpose. Regulatory expectations for a bioassay include a characterization of features, such as accuracy, precision, linearity, and range. The journey of a bioassay typically starts in a development lab, where it is initially qualified and used to support the release and stability testing of clinical lots. As a program moves through the different clinical phases, it may be optimized further, used to support process development, or transferred to new laboratories, with each activity generating additional bioassay data. Finally, the bioassay is fully validated as part of the transfer to the commercial quality control testing laboratories. In this work, rather than capturing the data from each study as a separate, independent report, it is proposed that, beginning with the qualification study, the accuracy and precision of the bioassay be continuously characterized, with each subsequent study result building upon the preceding ones. We call this approach continuous qualification Such a proposition is naturally carried out using Bayesian statistical methods in which the historical study data is used to construct prior knowledge that is blended with the current study data. By doing so, the bioassay accuracy and precision may be assessed with high confidence well ahead of commercial manufacturing. Further, by following the total-variance approach, the method also allows for a robust construction of system suitability and control limits for potency.

A single homogeneous assay for simultaneous measurement of bispecific antibody target binding.

Bispecific antibodies (BsAbs) are engineered to simultaneously bind two different antigens, and offer promising clinical outcomes for various diseases. The dual binding properties of BsAbs may enable superior efficacies and/or potencies compared to standard monoclonal antibodies (mAbs) or combination mAb therapies. Characterizing BsAb binding properties is critical during biotherapeutic development, where data is leveraged to predict efficacy and potency, assess critical quality attributes and improve antibody design. Traditional single-target, single-readout approaches (e.g., ELISA) have limited usefulness for interpreting complex bispecific binding, and double the benchwork. To address these deficiencies, we developed and implemented a new dual-target/readout binding assay that accurately dissects the affinities of both BsAb binding domains directly and simultaneously. This new assay uses AlphaPlex® technology, which eliminates traditional ELISA wash steps and can be miniaturized for automated workflows. The optimized BsAb AlphaPlex assay demonstrates 99-107% accuracy within a 50-150% linear range, and detected >50% binding degradation from photo- and thermal stress conditions. To the best of our knowledge, this is the first instance of a dual-target/readout BsAb AlphaPlex assay with GMP-suitable linear range, accuracy, specificity, and stability-indicating properties. As a highly customizable and efficient assay, BsAb AlphaPlex may be applicable to numerous bispecific formats and/or co-formulations against a variety of antigens beyond the clinical therapeutic space.

Prevention of Fab-arm exchange and antibody reduction via stabilization of the IgG4 hinge region.

IgG4s are dynamic molecules that undergo a process called Fab-arm exchange. Disulfide bonds between heavy chains are transiently reduced, resulting in half antibodies that reform intact antibodies with other IgG4 half antibodies. In vivo, therapeutic IgG4s can recombine with endogenous IgG4s, resulting in a heterogeneous mixture of bispecific antibodies. A related issue that can occur for any therapeutic protein during manufacturing is interchain disulfide bond reduction. For IgG4s, this primarily results in high levels of half-mAb that persist through purification processes. The S228P mutation has been used to prevent half-mAb formation. However, we demonstrated that IgG4s with the S228P mutation are subject to half-mAb formation and Fab-arm exchange in reducing environments. We identified two novel mutations that stabilize the heavy-heavy chain interaction via incorporation of additional disulfide bonds in the hinge region. Individually, these mutations increase stability toward reduction and lessen Fab-arm exchange. Combination of all three mutations, Y219C, G220C, and S228P, has an additive benefit resulting in an IgG4 with ˃7-fold increase in stability toward reduction while preventing Fab-arm exchange. Importantly, the mutations do not affect antigen binding or Fc effector function. These mutations hold great promise for solving mAb reduction during manufacturing and preventing Fab-arm exchange in vivo.

Characterization and analysis of scFv-IgG bispecific antibody size variants.

Bispecific antibodies are an emergent class of biologics that is of increasing interest for therapeutic applications. In one bispecific antibody format, single-chain variable fragments (scFv) are linked to or inserted in different locations of an intact immunoglobulin G (IgG) molecule to confer dual epitope binding. To improve biochemical stability, cysteine residues are often engineered on the heavy- and light-chain regions of the scFv to form an intrachain disulfide bond. Although this disulfide bond often improves stability, it can also introduce unexpected challenges to manufacturing or development. We report size variants that were observed for an appended scFv-IgG bispecific antibody. Structural characterization studies showed that the size variants resulted from the engineered disulfide bond on the scFv, whereby the engineered disulfide was found to be either open or unable to form an intrachain disulfide bond due to cysteinylation or glutathionylation of the cysteines. Furthermore, the scFv engineered cysteines also formed intermolecular disulfide bonds, leading to the formation of highly stable dimers and aggregates. Because both the monomer variants and dimers showed lower bioactivity, they were considered to be product-related impurities that must be monitored and controlled. To this end, we developed and optimized a robust, precise, and accurate high-resolution size-exclusion chromatographic method, using a statistical design-of-experiments methodology.

Influence of own mother's milk on bronchopulmonary dysplasia and costs.

BACKGROUND: Human milk from the infant's mother (own mother's milk; OMM) feedings reduces the risk of several morbidities in very low birthweight (VLBW) infants, but limited data exist regarding its impact on bronchopulmonary dysplasia (BPD). OBJECTIVE: To prospectively study the impact of OMM received in the neonatal intensive care unit (NICU) on the risk of BPD and associated costs. DESIGN/METHODS: A 5-year prospective cohort study of the impact of OMM dose on growth, morbidity and NICU costs in VLBW infants. OMM dose was the proportion of enteral intake that consisted of OMM from birth to 36 weeks postmenstrual age (PMA) or discharge, whichever occurred first. BPD was defined as the receipt of oxygen and/or positive pressure ventilation at 36 weeks PMA. NICU costs included hospital and physician costs. RESULTS: The cohort consisted of 254 VLBW infants with mean birth weight 1027±257 g and gestational age 27.8±2.5 weeks. Multivariable logistic regression demonstrated a 9.5% reduction in the odds of BPD for every 10% increase in OMM dose (OR 0.905 (0.824 to 0.995)). After controlling for demographic and clinical factors, BPD was associated with an increase of US$41 929 in NICU costs. CONCLUSIONS: Increased dose of OMM feedings from birth to 36 weeks PMA was associated with a reduction in the odds of BPD in VLBW infants. Thus, high-dose OMM feeding may be an inexpensive, effective strategy to help reduce the risk of this costly multifactorial morbidity.

Energy dependence of photostimulable phosphor.

In this study, phantoms were used to illustrate the dependence of photostimulable phosphor's characteristic response on beam quality. These phantoms, consisting of sheets of acrylic and aluminum, represented an extremity, an abdomen, a skull and a chest. Images were taken with 50 to 65 kVp, 60 to 110 kVp, 65 to 80 kVp and 70 to 120 kVp, respectively. In general, the amount of resulting luminescence of the photostimulable phosphor per unit of air kerma (exposure) increased with kVp.

Construction and phenotypic characterization of HIV type 1 functional envelope clones of subtypes G and F.

Subtype G has been estimated to represent the fourth most prevalent clade in the HIV-1 pandemic and subtype F is widely circulating in parts of South America (frequently within BF recombinant forms) and in Romania. However, functional envelope clones of these subtypes are lacking, which are needed for studies on antibody-mediated neutralization, coreceptor usage, and efficiency of viral entry inhibitor drugs. Here we report the construction, neutralization properties, and coreceptor usage of HIV-1 functional envelope clones of subtypes G (n = 15) and F (n = 7). These clones were obtained through RT-PCR amplification of HIV-1 gp160 from plasma RNA, and were used for pseudovirus production. All 15 subtype G-enveloped pseudoviruses were resistant to neutralization by gp120-targeted broadly neutralizing monoclonal antibodies (MAbs) b12 and 2G12, while a majority were neutralized by gp41-targeted MAbs 2F5 and 4E10. With regard to the subtype F envelopes, all seven pseudoviruses were resistant to 2F5 and b12, six were resistant to G12, and six were neutralized by 4E10. Coreceptor usage testing revealed that 21 of 22 envelopes were CCR5-tropic, including all 15 subtype G envelopes, seven of which were from patients with CD4(+) T cell counts <200/ml. These results confirm the broadly neutralizing activity of 4E10 on envelope clones across all tested group M clades, including subtypes G and F, reveal the resistance of most subtype F-enveloped pseudoviruses to broadly neutralizing MAbs b12, 2G12, and 2F5, and suggest that, similarly to subtype C, CXCR4 tropism is uncommon in subtype G, even at advanced stages of infection.