Slow Delivery Immunization Enhances HIV Neutralizing Antibody and Germinal Center Responses via Modulation of Immunodominance.

Conventional immunization strategies will likely be insufficient for the development of a broadly neutralizing antibody (bnAb) vaccine for HIV or other difficult pathogens because of the immunological hurdles posed, including B cell immunodominance and germinal center (GC) quantity and quality. We found that two independent methods of slow delivery immunization of rhesus monkeys (RMs) resulted in more robust T follicular helper (TFH) cell responses and GC B cells with improved Env-binding, tracked by longitudinal fine needle aspirates. Improved GCs correlated with the development of >20-fold higher titers of autologous nAbs. Using a new RM genomic immunoglobulin locus reference, we identified differential IgV gene use between immunization modalities. Ab mapping demonstrated targeting of immunodominant non-neutralizing epitopes by conventional bolus-immunized animals, whereas slow delivery-immunized animals targeted a more diverse set of epitopes. Thus, alternative immunization strategies can enhance nAb development by altering GCs and modulating the immunodominance of non-neutralizing epitopes.

Vaccine-Induced Protection from Homologous Tier 2 SHIV Challenge in Nonhuman Primates Depends on Serum-Neutralizing Antibody Titers.

Passive administration of HIV neutralizing antibodies (nAbs) can protect macaques from hard-to-neutralize (tier 2) chimeric simian-human immunodeficiency virus (SHIV) challenge. However, conditions for nAb-mediated protection after vaccination have not been established. Here, we selected groups of 6 rhesus macaques with either high or low serum nAb titers from a total of 78 animals immunized with recombinant native-like (SOSIP) Env trimers. Repeat intrarectal challenge with homologous tier 2 SHIVBG505 led to rapid infection in unimmunized and low-titer animals. High-titer animals, however, demonstrated protection that was gradually lost as nAb titers waned over time. An autologous serum ID50 nAb titer of ∼1:500 afforded more than 90% protection from medium-dose SHIV infection. In contrast, antibody-dependent cellular cytotoxicity and T cell activity did not correlate with protection. Therefore, Env protein-based vaccination strategies can protect against hard-to-neutralize SHIV challenge in rhesus macaques by inducing tier 2 nAbs, provided appropriate neutralizing titers can be reached and maintained.

Velopharyngeal Characteristics in Aarskog-Scott Syndrome: A Case Report.

Aarskog-Scott syndrome (AAS), also known as facio-digito-genital syndrome, is a rare heterogenous syndrome characterized by facial dysmorphism, brachydactyly, and genetic abnormalities. Although severe craniofacial abnormalities have been reported in AAS, little is known about speech and resonance issues in AAS. Specifically, published data to date have only indicated reports of hypernasality associated with a cleft palate in AAS. This case report provides clinical and anatomic information surrounding hypernasal speech in the absence of an overt cleft palate in a patient with AAS.

Outpatient clinical pharmacy practice in the face of COVID-19 at a cancer center in New York City.

PURPOSE: With the rapid spread of COVID-19 in New York City since early March 2020, innovative measures were needed for clinical pharmacy specialists to provide direct clinical care safely to cancer patients. Allocating the workforce was necessary to meet the surging needs of the inpatient services due to the COVID-19 outbreak, which had the potential to compromise outpatient services. We present here our approach of restructuring clinical pharmacy services and providing direct patient care in outpatient clinics during the pandemic. DATA SOURCES: We conducted a retrospective review of electronic clinical documentation involving clinical pharmacy specialist patient encounters in 9 outpatient clinics from March 1, 2020 to May 31, 2020. The analysis of the clinical pharmacy specialist interventions and the impact of the interventions was descriptive. DATA SUMMARY: As hospital services were modified to handle the surge due to COVID-19, select clinical pharmacy specialists were redeployed from the outpatient clinics or research blocks to COVID-19 inpatient teams. During these 3 months, clinical pharmacy specialists were involved in 2535 patient visits from 9 outpatient clinics and contributed a total of 4022 interventions, the majority of which utilized telemedicine. The interventions provided critical clinical pharmacy care during the pandemic and omitted 199 in-person visits for medical care. CONCLUSION: The swift transition to telemedicine allowed the provision of direct clinical pharmacy services to patients with cancer during the COVID-19 pandemic.

Evaluation of toxicity of carmustine with or without bevacizumab in patients with recurrent or progressive high grade gliomas.

PURPOSE: An increased incidence in hematologic toxicity has been reported with the addition of bevacizumab to lomustine for patients with recurrent or progressive high grade gliomas (HGG). Data regarding incidence of toxicity with combination bevacizumab and carmustine is limited. The purpose of this study is to compare toxicity of single agent carmustine and carmustine plus bevacizumab for patients with HGGs. METHODS: This single center retrospective study at Memorial Sloan Kettering Cancer Center included pathologically confirmed HGG with age ≥ 18 years who received carmustine between January 2003 and May 2017. RESULTS: Sixty-five patients with HGGs collectively received 110 doses of BCNU during the specified time period. Sixteen patients received single agent BCNU (30 doses); 49 patients received combination bevacizumab with BCNU (80 doses). There was no significant difference in incidence or grade of toxicity between single agent and combination therapy with respect to hepatotoxicity, leukopenia, lymphopenia, neutropenia, anemia, and thrombocytopenia. Rates of grade 3 and 4 neutropenia (20% vs 13.8%, p = 0.55) and thrombocytopenia (23.3% vs 23.8%, p = 1) did not differ between single agent BCNU versus combination therapy. When stratified based on dose ( < 150 mg/m2, 150 mg/m2, > 150 mg/m2), there was no statistically significant difference between the two groups with respect to grade 3 and 4 neutropenia or thrombocytopenia. CONCLUSIONS: This is the first study to report the toxicity of carmustine with or without bevacizumab for the treatment of recurrent and refractory HGG. The addition of bevacizumab to carmustine did not increase incidence or grade of hematologic toxicity when compared to single agent carmustine.

CXCL13 is a plasma biomarker of germinal center activity.

Significantly higher levels of plasma CXCL13 [chemokine (C-X-C motif) ligand 13] were associated with the generation of broadly neutralizing antibodies (bnAbs) against HIV in a large longitudinal cohort of HIV-infected individuals. Germinal centers (GCs) perform the remarkable task of optimizing B-cell Ab responses. GCs are required for almost all B-cell receptor affinity maturation and will be a critical parameter to monitor if HIV bnAbs are to be induced by vaccination. However, lymphoid tissue is rarely available from immunized humans, making the monitoring of GC activity by direct assessment of GC B cells and germinal center CD4(+) T follicular helper (GC Tfh) cells problematic. The CXCL13-CXCR5 [chemokine (C-X-C motif) receptor 5] chemokine axis plays a central role in organizing both B-cell follicles and GCs. Because GC Tfh cells can produce CXCL13, we explored the potential use of CXCL13 as a blood biomarker to indicate GC activity. In a series of studies, we found that plasma CXCL13 levels correlated with GC activity in draining lymph nodes of immunized mice, immunized macaques, and HIV-infected humans. Furthermore, plasma CXCL13 levels in immunized humans correlated with the magnitude of Ab responses and the frequency of ICOS(+) (inducible T-cell costimulator) Tfh-like cells in blood. Together, these findings support the potential use of CXCL13 as a plasma biomarker of GC activity in human vaccine trials and other clinical settings.

A Cytokine-Independent Approach To Identify Antigen-Specific Human Germinal Center T Follicular Helper Cells and Rare Antigen-Specific CD4+ T Cells in Blood.

Detection of Ag-specific CD4(+) T cells is central to the study of many human infectious diseases, vaccines, and autoimmune diseases. However, such cells are generally rare and heterogeneous in their cytokine profiles. Identification of Ag-specific germinal center (GC) T follicular helper (Tfh) cells by cytokine production has been particularly problematic. The function of a GC Tfh cell is to selectively help adjacent GC B cells via cognate interaction; thus, GC Tfh cells may be stingy cytokine producers, fundamentally different from Th1 or Th17 cells in the quantities of cytokines produced. Conventional identification of Ag-specific cells by intracellular cytokine staining relies on the ability of the CD4(+) T cell to generate substantial amounts of cytokine. To address this problem, we have developed a cytokine-independent activation-induced marker (AIM) methodology to identify Ag-specific GC Tfh cells in human lymphoid tissue. Whereas Group A Streptococcus-specific GC Tfh cells produced minimal detectable cytokines by intracellular cytokine staining, the AIM method identified 85-fold more Ag-specific GC Tfh cells. Intriguingly, these GC Tfh cells consistently expressed programmed death ligand 1 upon activation. AIM also detected non-Tfh cells in lymphoid tissue. As such, we applied AIM for identification of rare Ag-specific CD4(+) T cells in human peripheral blood. Dengue, tuberculosis, and pertussis vaccine-specific CD4(+) T cells were readily detectable by AIM. In summary, cytokine assays missed 98% of Ag-specific human GC Tfh cells, reflecting the biology of these cells, which could instead be sensitively identified by coexpression of TCR-dependent activation markers.

Cytokine-Independent Detection of Antigen-Specific Germinal Center T Follicular Helper Cells in Immunized Nonhuman Primates Using a Live Cell Activation-Induced Marker Technique.

A range of current candidate AIDS vaccine regimens are focused on generating protective HIV-neutralizing Ab responses. Many of these efforts rely on the rhesus macaque animal model. Understanding how protective Ab responses develop and how to increase their efficacy are both major knowledge gaps. Germinal centers (GCs) are the engines of Ab affinity maturation. GC T follicular helper (Tfh) CD4 T cells are required for GCs. Studying vaccine-specific GC Tfh cells after protein immunizations has been challenging, as Ag-specific GC Tfh cells are difficult to identify by conventional intracellular cytokine staining. Cytokine production by GC Tfh cells may be intrinsically limited in comparison with other Th effector cells, as the biological role of a GC Tfh cell is to provide help to individual B cells within the GC, rather than secreting large amounts of cytokines bathing a tissue. To test this idea, we developed a cytokine-independent method to identify Ag-specific GC Tfh cells. RNA sequencing was performed using TCR-stimulated GC Tfh cells to identify candidate markers. Validation experiments determined CD25 (IL-2Rα) and OX40 to be highly upregulated activation-induced markers (AIM) on the surface of GC Tfh cells after stimulation. In comparison with intracellular cytokine staining, the AIM assay identified >10-fold more Ag-specific GC Tfh cells in HIV Env protein-immunized macaques (BG505 SOSIP). CD4 T cells in blood were also studied. In summary, AIM demonstrates that Ag-specific GC Tfh cells are intrinsically stingy producers of cytokines, which is likely an essential part of their biological function.

Hypoalbuminemia is significantly associated with increased clearance time of high dose methotrexate in patients being treated for lymphoma or leukemia.

As a weak acid, methotrexate (MTX) is bound to serum albumin and has variable protein binding. The purpose of this study was to assess serum albumin's relationship with MTX pharmacokinetics by comparing MTX clearance and toxicities between patients with normal serum albumin to those with hypoalbuminemia. This single-center retrospective study included adult patients with leukemia or lymphoma who received their first MTX at a dose ≥1 g/m2. Hypoalbuminemia was defined as serum albumin ≤3.4 g/dL. MTX clearance was defined as the first documented time the MTX level ≤0.05 µM. Fisher's exact tests and Wilcoxon rank sum tests were used to examine differences in toxicities, and Cox proportional hazard regression was used to assess relationship with time to clearance. Of 523 patients identified, 167 patients were evaluable. One hundred thirty-five patients had normal serum albumin and 32 had hypoalbuminemia. Hypoalbuminemia was associated with a higher proportion of patients experiencing edema, ascites or pleural effusions (34 vs. 12 %, p = 0.006), and the concomitant use of nephrotoxic agents (41 vs. 20 %, p = 0.021). Hypoalbuminemia was associated with a significantly longer time to MTX clearance (median 96 vs. 72 h, p = 0.004). In addition, patients with hypoalbuminemia had a higher proportion of hyperbilirubinemia and significantly longer hospitalization (median 14 vs. 5 days, p < 0.001). In conclusion, hypoalbuminemia was associated with increased time to MTX clearance and increased length of hospitalization. High dose MTX is safe to administer in patients with low albumin levels, with appropriate leucovorin rescue, and good supportive care.