A molecularly engineered lectin destroys EGFR and inhibits the growth of non-small cell lung cancer

Survival rates for non-small cell lung cancer (NSCLC) remain low despite the advent of novel therapeutics. Tyrosine kinase inhibitors (TKIs) targeting mutant epidermal growth factor receptor (EGFR) in NSCLC have significantly improved mortality but are plagued with challenges--they can only be used in the small fraction of patients who have susceptible driver mutations, and resistance inevitably develops. Aberrant glycosylation on the surface of cancer cells is an attractive therapeutic target as these abnormal glycosylation patterns are typically specific to cancer cells and are not present on healthy cells. H84T BanLec (H84T), a lectin previously engineered by our group to separate its antiviral activity from its mitogenicity, exhibits precision binding of high mannose, an abnormal glycan present on the surface of many cancer cells, including NSCLC. Here, we show that H84T binds to and inhibits the growth of diverse NSCLC cell lines by inducing lysosomal degradation of EGFR and leading to cancer cell death through autophagy. This is a mechanism distinct from EGFR TKIs and is independent of EGFR mutation status; H84T inhibited proliferation of both cell lines expressing wild type EGFR and those expressing mutant EGFR that is resistant to all TKIs. Further, H84T binds strongly to multiple and diverse clinical samples of both pulmonary adenocarcinoma and squamous cell carcinoma. H84T is thus a promising potential therapeutic in NSCLC, with the ability to circumvent the challenges currently faced by EGFR TKIs.

SARS-CoV-2 shedding and evolution in patients who were immunocompromised during the omicron period: a multicentre, prospective analysis

BACKGROUND

Prolonged SARS-CoV-2 infections in people who are immunocompromised might predict or source the emergence of highly mutated variants. The types of immunosuppression placing patients at highest risk for prolonged infection have not been systematically investigated. We aimed to assess risk factors for prolonged SARS-CoV-2 infection and associated intrahost evolution.

METHODS

In this multicentre, prospective analysis, participants were enrolled at five US medical centres. Eligible patients were aged 18 years or older, were SARS-CoV-2-positive in the previous 14 days, and had a moderately or severely immunocompromising condition or treatment. Nasal specimens were tested by real-time RT-PCR every 2-4 weeks until negative in consecutive specimens. Positive specimens underwent viral culture and whole genome sequencing. A Cox proportional hazards model was used to assess factors associated with duration of infection.

FINDINGS

From April 11, 2022, to Oct 1, 2022, 156 patients began the enrolment process, of whom 150 were enrolled and included in the analyses. Participants had B-cell malignancy or anti-B-cell therapy (n=18), solid organ transplantation or haematopoietic stem-cell transplantation (HSCT; n=59), AIDS (n=5), non-B-cell malignancy (n=23), and autoimmune or autoinflammatory conditions (n=45). 38 (25%) participants were real-time RT-PCR-positive and 12 (8%) were culture-positive 21 days or longer after initial SARS-CoV-2 detection or illness onset. Compared with the group with autoimmune or autoinflammatory conditions, patients with B-cell dysfunction (adjusted hazard ratio 0·32 [95% CI 0·15-0·64]), solid organ transplantation or HSCT (0·60 [0·38-0·94]), and AIDS (0·28 [0·08-1·00]) had longer duration of infection, defined as time to last positive real-time RT-PCR test. There was no significant difference in the non-B-cell malignancy group (0·58 [0·31-1·09]). Consensus de novo spike mutations were identified in five individuals who were real-time RT-PCR-positive longer than 56 days; 14 (61%) of 23 were in the receptor-binding domain. Mutations shared by multiple individuals were rare (<5%) in global circulation.

INTERPRETATION

In this cohort, prolonged replication-competent omicron SARS-CoV-2 infections were uncommon. Within-host evolutionary rates were similar across patients, but individuals with infections lasting longer than 56 days accumulated spike mutations, which were distinct from those seen globally. Populations at high risk should be targeted for repeated testing and treatment and monitored for the emergence of antiviral resistance.

FUNDING

US Centers for Disease Control and Prevention.

Outpatient Treatment for COVID-19

This JAMA Patient Page describes current medications available for outpatient treatment of COVID-19 (nirmatrelvir-ritonavir, remdesivir, and molnupiravir), their effectiveness, and how to obtain them.

SARS-CoV-2 shedding and evolution in immunocompromised hosts during the Omicron period: a multicenter prospective analysis

Background

Prolonged SARS-CoV-2 infections in immunocompromised hosts may predict or source the emergence of highly mutated variants. The types of immunosuppression placing patients at highest risk for prolonged infection and associated intrahost viral evolution remain unclear.

Methods

Adults aged ≥18 years were enrolled at 5 hospitals and followed from 4/11/2022 - 2/1/2023. Eligible patients were SARS-CoV-2-positive in the previous 14 days and had a moderate or severely immunocompromising condition or treatment. Nasal specimens were tested by rRT-PCR every 2-4 weeks until negative in consecutive specimens. Positive specimens underwent viral culture and whole genome sequencing. A Cox proportional hazards model was used to assess factors associated with duration of infection.

Results

We enrolled 150 patients with: B cell malignancy or anti-B cell therapy (n=18), solid organ or hematopoietic stem cell transplant (SOT/HSCT) (n=59), AIDS (n=5), non-B cell malignancy (n=23), and autoimmune/autoinflammatory conditions (n=45). Thirty-eight (25%) were rRT-PCR-positive and 12 (8%) were culture-positive ≥21 days after initial SARS-CoV-2 detection or illness onset. Patients with B cell dysfunction had longer duration of rRT-PCR-positivity compared to those with autoimmune/autoinflammatory conditions (aHR 0.32, 95% CI 0.15-0.64). Consensus (>50% frequency) spike mutations were identified in 5 individuals who were rRT-PCR-positive >56 days; 61% were in the receptor-binding domain (RBD). Mutations shared by multiple individuals were rare (<5%) in global circulation.

Conclusions

In this cohort, prolonged replication-competent Omicron SARS-CoV-2 infections were uncommon. Within-host evolutionary rates were similar across patients, but individuals with infections lasting >56 days accumulated spike mutations, which were distinct from those seen globally.

Antimicrobial stewardship in solid organ transplant recipients: Current challenges and proposed metrics

BACKGROUND

Solid organ transplant (SOT) recipients are challenging populations for antimicrobial stewardship interventions due to a variety of reasons, including immunosuppression, consequent risk of opportunistic and donor-derived infections, high rates of infection with multi-drug resistant organisms (MDROs), Clostridioides difficile, and need for prolonged antimicrobial prophylaxis. Despite this, data on stewardship interventions and metrics that address the distinct needs of these patients are limited.

METHODS

We performed a narrative review of the current state of antimicrobial stewardship in SOT recipients, existing interventions and metrics in this population, and considerations for implementation of transplant-specific stewardship programs.

RESULTS

Antimicrobial stewardship metrics are evolving even in the general patient population. Data on metrics applicable to the SOT population are even more limited. Standard process, outcomes, and balancing metrics may not always apply to the SOT population. A successful stewardship program for SOT recipients requires reviewing existing data, applying general stewardship principles, and understanding the nuances of SOT patients.

CONCLUSION

As antimicrobial stewardship interventions are being implemented in SOT recipients; new metrics are needed to assess their impact. In conclusion, SOT patients present a challenging but important opportunity for antimicrobial stewards.

ABBREVIATIONS

SOT, antimicrobial stewardship program, MDRO, Clostridioides difficile infection, Centers for Disease Control and Prevention, Infectious Diseases Society of America, prospective audit and feedback, hematopoietic cell transplant, cytomegalovirus, trimethoprim-sulfamethoxazole, surgical site infections, nucleic acid amplification testing, days of therapy, defined daily dose, and length of stay.

Targeting glycans for CAR therapy: The advent of sweet CARs

Chimeric antigen receptor (CAR) T cell therapy has created a paradigm shift in the treatment of hematologic malignancies but has not been as effective toward solid tumors. For such tumors, the primary obstacles facing CAR T cells are scarcity of tumor-specific antigens and the hostile and complex tumor microenvironment. Glycosylation, the process by which sugars are post-translationally added to proteins or lipids, is profoundly dysregulated in cancer. Abnormally glycosylated glycoproteins expressed on cancer cells offer unique targets for CAR T therapy as they are specific to tumor cells. Tumor stromal cells also express abnormal glycoproteins and thus also have the potential to be targeted by glycan-binding CAR T cells. This review will discuss the state of CAR T cells in the therapy of solid tumors, the cancer glycoproteome and its potential for use as a therapeutic target, and the landscape and future of glycan-binding CAR T cell therapy.

Targeted disruption of pi-pi stacking in Malaysian banana lectin reduces mitogenicity while preserving antiviral activity

Lectins, carbohydrate-binding proteins, have been regarded as potential antiviral agents, as some can bind glycans on viral surface glycoproteins and inactivate their functions. However, clinical development of lectins has been stalled by the mitogenicity of many of these proteins, which is the ability to stimulate deleterious proliferation, especially of immune cells. We previously demonstrated that the mitogenic and antiviral activities of a lectin (banana lectin, BanLec) can be separated via a single amino acid mutation, histidine to threonine at position 84 (H84T), within the third Greek key. The resulting lectin, H84T BanLec, is virtually non-mitogenic but retains antiviral activity. Decreased mitogenicity was associated with disruption of pi-pi stacking between two aromatic amino acids. To examine whether we could provide further proof-of-principle of the ability to separate these two distinct lectin functions, we identified another lectin, Malaysian banana lectin (Malay BanLec), with similar structural features as BanLec, including pi-pi stacking, but with only 63% amino acid identity, and showed that it is both mitogenic and potently antiviral. We then engineered an F84T mutation expected to disrupt pi-pi stacking, analogous to H84T. As predicted, F84T Malay BanLec (F84T) was less mitogenic than wild type. However, F84T maintained strong antiviral activity and inhibited replication of HIV, Ebola, and other viruses. The F84T mutation disrupted pi-pi stacking without disrupting the overall lectin structure. These findings show that pi-pi stacking in the third Greek key is a conserved mitogenic motif in these two jacalin-related lectins BanLec and Malay BanLec, and further highlight the potential to rationally engineer antiviral lectins for therapeutic purposes.

Tumor matrix protein collagen XIα1 in cancer

The extracellular matrix is increasingly recognized as an essential player in cancer development and progression. Collagens are one of the most important components of the extracellular matrix, and have themselves been implicated in many aspects of neoplastic transformation. Collagen XI is a minor collagen whose main physiologic function is to regulate the diameter of major collagen fibrils. The α1 chain of collagen XI (colXIα1) has known pathogenic roles in several musculoskeletal disorders. Recent research has highlighted the importance of colXIα1 in many types of cancer, including its roles in metastasis, angiogenesis, and drug resistance, as well as its potential utility in screening tests and as a therapeutic target. High levels of colXIα1 overexpression have been reported in multiple expression profile studies examining differences between cancerous and normal tissue, and between beginning and advanced stage cancer. Its expression has been linked to poor progression-free and overall survival. The consistency of these data across cancer types is particularly striking, including colorectal, ovarian, breast, head and neck, lung, and brain cancers. This review discusses the role of collagen XIα1 in cancer and its potential as a target for cancer therapy.

IL28B genotype and the expression of ISGs in normal liver

BACKGROUND & AIMS

Both polymorphisms in the IL28B gene locus and ISG expression levels are associated with the outcome of hepatitis C virus (HCV) infection. The two are also interrelated, although the mechanism is unknown. Favourable CC genotype at rs12979860 expresses lower baseline ISG levels and responds better to treatment than unfavourable CT and TT genotypes. Little is known about this relationship in normal, uninfected liver. This study sought to explore this relationship.

METHODS

Normal human liver specimens (64) and HCV positive human liver specimens (95) were genotyped for IL28B rs12979860 C > T. mRNA levels of ISGs and other relevant genes were studied by qPCR.

RESULTS

Most studied ISGs had significantly different expression by IL28B genotype in normal liver. CC genotype expressed the highest levels, CT intermediate and TT the lowest. This is opposite to the pattern seen in HCV patients. Principal component analysis of IL28B genotype and ISG expression further revealed a distinct set of genes correlated with the C allele (ISG15, HTATIP2, LGALS3BP, IRF2 and BCL2) and T allele (IFNα, β, γ, λ3 and CD80).

CONCLUSION

A subset of ISGs was found to be differentially expressed in normal liver by IL28B genotype. This suggests a relationship between IL28B genotype and gene expression before HCV infection.

The interaction between HCV and nuclear receptor-mediated pathways

Hepatitis C virus (HCV) is presently the leading indication for liver transplantation in Western countries. Treatment for HCV infection includes a combination of pegylated interferon and ribavirin, which produces highly variable response rates. This reflects the lack of information regarding the roles of host and viral components during viral pathogenesis. Vital processes regulated by the liver, including metabolism, lipid homeostasis, cellular proliferation, and the immune response, are known to be systematically dysregulated as a result of persistent HCV infection. Nuclear receptors and their ligands are recognized as indispensable regulators of liver homeostasis. Pathways mediated by the nuclear receptor superfamily have been shown to be profoundly disrupted during HCV infection, leading to an increased importance in elucidating the exact nature of this complex relationship. Expanded understanding of the role of nuclear receptors in HCV infection may therefore be an essential step in the search for a more universally effective treatment.