DNAJB1-PRKACA fusion neoantigens elicit rare endogenous T cell responses that potentiate cell therapy for fibrolamellar carcinoma

Fibrolamellar carcinoma (FLC) is a liver tumor with a high mortality burden and few treatment options. A promising therapeutic vulnerability in FLC is its driver mutation, a conserved DNAJB1-PRKACA gene fusion that could be an ideal target neoantigen for immunotherapy. In this study, we aim to define endogenous CD8 T cell responses to this fusion in FLC patients and evaluate fusion-specific T cell receptors (TCRs) for use in cellular immunotherapies. We observe that fusion-specific CD8 T cells are rare and that FLC patient TCR repertoires lack large clusters of related TCR sequences characteristic of potent antigen-specific responses, potentially explaining why endogenous immune responses are insufficient to clear FLC tumors. Nevertheless, we define two functional fusion-specific TCRs, one of which has strong anti-tumor activity in vivo. Together, our results provide insights into the fragmented nature of neoantigen-specific repertoires in humans and indicate routes for clinical development of successful immunotherapies for FLC.

LB0001 BIMEKIZUMAB IN BDMARD-NAIVE PATIENTS WITH PSORIATIC ARTHRITIS: 24-WEEK EFFICACY & SAFETY FROM BE OPTIMAL, A PHASE 3, MULTICENTRE, RANDOMISED, PLACEBO-CONTROLLED, ACTIVE REFERENCE STUDY

Background

Bimekizumab (BKZ) is a monoclonal IgG1 antibody that selectively inhibits IL-17F in addition to IL-17A.

Objectives

Assess BKZ efficacy and safety vs PBO in bDMARD-naïve pts with active PsA to Wk 24 of BE OPTIMAL.

Methods

BE OPTIMAL (NCT03895203) comprises 16 wks double-blind PBO-controlled and 36 wks treatment-blind. Pts were ≥18 yrs, bDMARD-naïve, with adult-onset, active PsA, ≥3 tender and ≥3 swollen joints. Pts randomised 3:2:1, subcutaneous BKZ 160 mg Q4W:PBO:adalimumab (ADA; reference arm) 40 mg Q2W. From Wk 16, PBO pts received BKZ 160 mg Q4W. Primary endpoint: ACR50 at Wk 16.

Results

821/852 (96.4%) pts completed Wk 16 and 806 (94.6%) Wk 24. Mean age 48.7 yrs, BMI 29.2 kg/m2; since diagnosis: 5.9 yrs; 46.8% male. BL characteristics comparable across arms. Primary endpoint met (Wk 16 ACR50: 43.9% BKZ vs 10.0% PBO, p<0.001; ADA: 45.7%; Figure 1). All ranked secondary endpoints met at Wk 16 (Table 1). As early as Wk 2, ACR20 was higher in BKZ vs PBO (27.1% vs 7.8%, nominal p<0.001; ADA: 33.6%). Outcomes continued to improve at Wk 24 (Table 1). To Wk 16, pts with ≥1 TEAE, BKZ: 59.9%; PBO: 49.5%; ADA: 59.3%. SAE rate low (1.6%; 1.1%; 1.4%). Most frequent (≥5%) AEs for all arms: nasopharyngitis (9.3%; 4.6%; 5.0%), URTI (4.9%; 6.4%; 2.1%), increased ALT (0.7%; 0.7%; 5.0%). Candida infections: 2.6%, 0.7%, 0%; no systemic candidiasis. 2 malignancies (BKZ: basal cell carcinoma; PBO: breast cancer stage 1); no MACE, uveitis, IBD or deaths.

Table 1.

Wk 16 and 24 efficacy

BLWk 16Wk 24PBO N=281BKZ 160 mg Q4W N=431ADA 40 mg Q2W N=140†PBO N=281BKZ 160 mg Q4W N=431ADA 40 mg Q2W N=140†p value (BKZ vs PBO)PBO→ BKZ 160 mg Q4WaN=281BKZ 160 mg Q4W N=431ADA 40 mg Q2W N=140†Ranked endpointsbACR50 [NRI],–––28189 (43.9)64<0.00110119666n (%)-10-45.7(35.9)(45.5)-47.1HAQ-DI CfB [MI],0.890.820.86−0.09 (0.03)−0.26 (0.02)−0.33<0.001c−0.28−0.30−0.34mean (SE)-0.04-0.03-0.05(0.04)(0.03)(0.02)(0.05)PASI90d [NRI],–––4133 (61.3)f28<0.00186 (61.4)e158 (72.8)f32n (%)(2.9)e(41.2)g(47.1)gSF-36 PCS CfB [MI],36.938.137.62.36.36.8<0.001c6.27.37.3mean (SE)-0.6-0.5-0.7-0.5-0.4-0.8-0.5-0.4-0.8MDA [NRI],51413719463<0.00110620967n (%)-1.8-3.2-0.7-13.2(45.0)-45(37.7)(48.5)-47.9vdHmTSS CfB (subgroup)h [MI], mean (SE)15.67 (1.80)i15.56 (1.69)j17.39 (2.89)k0.36 (0.10)i−0.01 (0.04)j−0.06 (0.08)k<0.001c–––vdHmTSS CfB [MI],mean (SE)13.31 (1.56)l13.44 (1.47)m14.55 (2.44)n0.31 (0.09)l0(0.04)m−0.03 (0.07)n0.001c–––Other endpointsACR20 [NRI],–––6726896<0.001o17528299n (%)-23.8(62.2)-68.6(62.3)(65.4)-70.7ACR70 [NRI],–––1210539<0.001o5312642n (%)-4.3(24.4)-27.9-18.9(29.2)-30PASI100d [NRI],–––3103f14<0.001o6012226n (%)(2.1)e(47.5)(20.6)g(42.9)e (56.2)f(38.2)gTJC CfB [MI],17.116.817.5−3.2−10.0−10.9<0.001o−9.4−11.5−11.8mean (SE)-0.7-0.6-1.1(0.7) (0.5)-1(0.7)(0.5)-0.9SJC CfB [MI],9.599.6−3.0 (0.5)−6.6 (0.3)−7.5<0.001o−6.8 (0.4)−7.2 (0.3)−7.9mean (SE)-0.4-0.3-0.6-0.6-0.6

Randomised set. Interim results.

†Reference arm; study not powered for statistical comparisons of ADA to BKZ or PBO.

aPBO→BKZ pts received PBO to Wk 16, switched to BKZ 160 mg Q4W through Wk 24 (8 wks BKZ);

bResolution of enthesitis/dactylitis in pts with LEI>0/LDI>0 at BL pooled with BE COMPLETE (Wk 16 LEI=0 BKZ: 124/249 [49.8%], PBO: 37/106 [34.9%], p=0.008; LDI=0 BKZ: 68/90 [75.6%], PBO: 24/47 [51.1%], p=0.002);

cContinuous outcome p values calculated with RBMI data;

dPts with PSO and ≥3% BSA at BL;

en=140;

fn=217;

gn=68;

hPts with hs-CRP ≥6 mg/L and/or bone erosion at BL;

in=221;

jn=357;

kn=108;

ln=261;

mn=416;

nn=131;

oNominal, not powered for multiplicity.

Conclusion

Dual inhibition of IL-17A and IL-17F with BKZ in bDMARD-naïve pts with active PsA resulted in rapid, clinically relevant improvements in musculoskeletal and skin outcomes vs PBO. No new safety signals observed.1,2

References

[1]Ritchlin CT Lancet 2020;395(10222):427–40; 2. Coates LC Ann Rheum Dis 2021;80:779–80(POS1022).

Disclosure of Interests

Iain McInnes Consultant of: AbbVie, BMS, Boehringer Ingelheim, Celgene, Eli Lilly, Janssen, Novartis, and UCB Pharma, Grant/research support from: BMS, Boehringer Ingelheim, Celgene, Janssen, UCB Pharma, Laura Coates Consultant of: AbbVie, Amgen, Boehringer Ingelheim, BMS, Celgene, Domain, Eli Lilly, Gilead, Galapagos, Janssen, Moonlake, Novartis, Pfizer, and UCB Pharma, Speakers bureau: AbbVie, Amgen, Biogen, Celgene, Eli Lilly, Galapagos, Gilead, GSK, Janssen, Medac, Novartis, Pfizer, and UCB Pharma, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, and UCB Pharma, Robert B.M. Landewé Consultant of: Abbott, Ablynx, Amgen, AstraZeneca, BMS, Centocor, GSK, Novartis, Merck, Pfizer, Roche, Schering-Plough, UCB Pharma, and Wyeth, Speakers bureau: Abbott, Amgen, BMS, Centocor, Merck, Pfizer, Roche, Schering-Plough, UCB Pharma, and Wyeth, Grant/research support from: Abbott, Amgen, Centocor, Novartis, Pfizer, Roche, Schering-Plough, UCB Pharma, and Wyeth, Philip J Mease Consultant of: AbbVie, Amgen, BMS, Boehringer Ingelheim, Eli Lilly, Galapagos, Gilead, GSK, Janssen, Novartis, Pfizer, Sun Pharma and UCB Pharma, Speakers bureau: AbbVie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer and UCB Pharma, Grant/research support from: AbbVie, Amgen, BMS, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, Sun Pharma and UCB Pharma, Christopher T. Ritchlin Consultant of: AbbVie, Amgen, Eli Lilly, Gilead, Janssen, Novartis, Pfizer and UCB Pharma, Grant/research support from: AbbVie, Amgen and UCB Pharma, Yoshiya Tanaka Consultant of: AbbVie, Ayumi, Daiichi-Sankyo, Eli Lilly, GSK, Sanofi, and Taisho, Speakers bureau: AbbVie, Amgen, Astellas, AstraZeneca, BMS, Boehringer-Ingelheim, Chugai, Eisai, Eli Lilly, Gilead, Mitsubishi-Tanabe, and YL Biologics, Grant/research support from: AbbVie, Asahi-Kasei, Boehringer-Ingelheim, Chugai, Corrona, Daiichi-Sankyo, Eisai, Kowa, Mitsubishi-Tanabe, and Takeda, Akihiko Asahina Grant/research support from: AbbVie, Amgen, Eisai, Eli Lilly, Janssen, Kyowa Kirin, LEO Pharma, Maruho, Mitsubishi Tanabe Pharma, Pfizer, Sun Pharma, Taiho Pharma, Torii Pharmaceutical, and UCB Pharma, Laure Gossec Consultant of: AbbVie, Amgen, BMS, Celltrion, Galapagos, Gilead, GSK, Janssen, Lilly, Novartis, Pfizer and UCB Pharma, Grant/research support from: Amgen, Galapagos, Lilly, Pfizer, Sandoz and UCB Pharma, Alice B Gottlieb Consultant of: Amgen, AnaptsysBio, Avotres Therapeutics, Boehringer Ingelheim, BMS, Dermavant, Eli Lilly, Incyte, Janssen, Novartis, Pfizer, Sanofi, Sun Pharma, UCB Pharma, and XBiotech, Grant/research support from: Boehringer Ingelheim, Janssen, Novartis, Sun Pharma, UCB Pharma, and XBiotech: all funds go to Mount Sinai Medical School, Richard B. Warren Consultant of: AbbVie, Almirall, Amgen, Arena, Astellas, Avillion, Biogen, BMS, Boehringer Ingelheim, Celgene, Eli Lilly, GSK, Janssen, LEO Pharma, Novartis, Pfizer, Sanofi, and UCB Pharma, Paid instructor for: Astellas, DiCE, GSK, and Union, Grant/research support from: AbbVie, Almirall, Janssen, LEO Pharma, Novartis, and UCB Pharma, Barbara Ink Shareholder of: GSK, UCB Pharma, Employee of: UCB Pharma, Deepak Assudani Shareholder of: UCB Pharma, Employee of: UCB Pharma, Jason Coarse Shareholder of: UCB Pharma, Employee of: UCB Pharma, Rajan Bajracharya Shareholder of: UCB Pharma, Employee of: UCB Pharma, Joseph F. Merola Consultant of: AbbVie, Amgen, Biogen, BMS, Dermavant, Eli Lilly, Janssen, Leo Pharma, Novartis, Pfizer, Regeneron, Sanofi, Sun Pharma, and UCB Pharma, Paid instructor for: Amgen, Abbvie, Biogen, BMS, Dermavant, Eli Lilly, Janssen, Leo Pharma, Novartis, Pfizer, Regeneron, Sanofi, Sun Pharma, and UCB Pharma

OP0255 BIMEKIZUMAB IN PATIENTS WITH ACTIVE PSORIATIC ARTHRITIS AND AN INADEQUATE RESPONSE TO TUMOUR NECROSIS FACTOR INHIBITORS: 16-WEEK EFFICACY & SAFETY FROM BE COMPLETE, A PHASE 3, MULTICENTRE, RANDOMISED PLACEBO-CONTROLLED STUDY

Background

Bimekizumab (BKZ) is a monoclonal IgG1 antibody that selectively inhibits IL-17F in addition to IL-17A. BKZ has shown sustained efficacy and tolerability up to 152 wks in a phase 2b study in patients (pts) with active psoriatic arthritis (PsA).1,2

Objectives

To assess efficacy and safety of BKZ vs placebo (PBO) in pts with active PsA and prior inadequate tumour necrosis factor inhibitor (TNFi) response in the 16-wk pivotal phase 3 study, BE COMPLETE.

Methods

BE COMPLETE (NCT03896581) comprises a 16-wk double-blind, PBO-controlled period. Pts were aged ≥18 yrs, had a diagnosis of adult-onset, active PsA with ≥3 tender joints and ≥3 swollen joints, and inadequate response or intolerance to treatment with 1 or 2 TNFi. Pts were randomised 2:1 to BKZ 160 mg Q4W or PBO. From Wk 16, pts were eligible to enter an open-label extension, receiving BKZ 160 mg Q4W. The primary endpoint was a ≥50% improvement in American College of Rheumatology response criteria (ACR50) at Wk 16. Primary and ranked secondary efficacy endpoints were assessed at Wk 16.

Results

Of 400 randomised pts (BKZ: 267; PBO: 133), 388 (97.0%) completed Wk 16 (BKZ: 263 [98.5%]; PBO: 125 [94.0%]). Baseline characteristics were comparable between groups: mean age 50.5 yrs, weight 86.0 kg, BMI 29.8 kg/m2, time since diagnosis 9.5 yrs; 47.5% pts were male.

At Wk 16, the primary endpoint (ACR50: 43.4% BKZ vs 6.8% PBO; p<0.001; Figure 1) and all ranked secondary endpoints (HAQ-DI CfB, PASI90, SF-36 PCS CfB and MDA response) were met (all p<0.001; Table 1). The ACR50 response was rapid with separation from PBO observed from Wk 4 (nominal p<0.001). Additional outcomes, including ACR20/70, TJC and SJC CfB, and PASI75/100, demonstrated numerical improvement with BKZ compared to PBO at Wk 16 (all nominal p<0.001; Table 1).

Table 1.

Disease characteristics at baseline and efficacy at Wk 16

PBO N=133BKZ 160 mg Q4W N=267p valueBaseline characteristicsTJCmean (SD)19.3 (14.2)18.4 (13.5)-SJCmean (SD)10.3 (8.2)9.7 (7.5)-PtGA-PsAmean (SD)63.0 (22.0)60.5 (22.5)-PtAAPmean (SD)61.7 (24.6)58.3 (24.2)-Psoriasis BSAn (%)<3%45 (33.8)91 (34.1)-≥3 to ≤10%63 (47.4)109 (40.8)->10%25 (18.8)67 (25.1)-PASIamean (SD)8.5 (6.6)b10.1 (9.1)c-Prior TNFin (%)Inadequate response to 1 TNFi103 (77.4)204 (76.4)-Inadequate response to 2 TNFi15 (11.3)29 (10.9)-Intolerance to TNFi15 (11.3)34 (12.7)-Current cDMARDsn (%)63 (47.4)139 (52.1)-Ranked endpoints in hierarchical orderACR50* [NRI] n (%)9 (6.8)116 (43.4)<0.001HAQ-DI CfB† [RBMI] mean (SE)–0.1 (0.0)–0.4 (0.0)<0.001PASI90†a [NRI]n (%)6 (6.8)b121 (68.8)c<0.001SF-36 PCS CfB† [RBMI]mean (SE)1.4 (0.7)7.3 (0.5)<0.001MDA Response† [NRI]n (%)8 (6.0)118 (44.2)<0.001Other endpointsACR20† [NRI]n (%)21 (15.8)179 (67.0)<0.001‡ACR70† [NRI] n (%)1 (0.8)71 (26.6)<0.001‡TJC CfB [MI] mean (SE)–2.4 (0.9)–10.9 (0.8)<0.001‡SJC CfB [MI] mean (SE)–2.0 (0.5)–7.0 (0.4)<0.001‡PASI75a [NRI]n (%)9 (10.2)b145 (82.4)c<0.001‡PASI100a [NRI]n (%)4 (4.5)b103 (58.5)c<0.001‡

Randomised set (N=400). *Primary endpoint; †Secondary endpoint; ‡Nominal p value. aIn patients with ≥3% BSA with PSO at BL; bn=88; cn=176.

Over 16 wks, 107/267 (40.1%) pts on BKZ had ≥1 TEAE vs 44/132 (33.3%) pts on PBO; the three most frequent TEAEs on BKZ were nasopharyngitis (BKZ: 3.7%; PBO: 0.8%), oral candidiasis (BKZ: 2.6%; PBO: 0%) and upper respiratory tract infection (BKZ: 2.2%; PBO: 1.5%). Incidence of SAEs was low (BKZ: 1.9%; PBO: 0%); none led to discontinuation. 2 pts on BKZ discontinued due to a TEAE (BKZ: 0.7%; PBO: 0%). No systemic candidiasis, cases of IBD, MACE, uveitis, VTE or deaths were reported.

Conclusion

Dual inhibition of IL-17A and IL-17F with BKZ in pts with active PsA and prior inadequate TNFi response resulted in rapid, clinically relevant and statistically significant improvements in efficacy outcomes vs PBO. No new safety signals were observed.1,2

References

[1]Ritchlin C.T. Lancet 2020;395(10222):427–40; 2. Coates L.C. Ann Rheum Dis 2021;80:779–80(POS1022).

Acknowledgements

This study was funded by UCB Pharma. Editorial services were provided by Costello Medical.

Disclosure of Interests

Joseph F. Merola Paid instructor for: Amgen, Abbvie, Biogen, BMS, Dermavant, Eli Lilly, Janssen, Leo Pharma, Novartis, Pfizer, Regeneron, Sanofi, Sun Pharma and UCB Pharma, Consultant of: Amgen, Abbvie, Biogen, BMS, Dermavant, Eli Lilly, Janssen, Leo Pharma, Novartis, Pfizer, Regeneron, Sanofi, Sun Pharma and UCB Pharma, Iain McInnes Consultant of: AbbVie, BMS, Boehringer Ingelheim, Celgene, Eli Lilly, Janssen, Novartis, and UCB Pharma, Grant/research support from: BMS, Boehringer Ingelheim, Celgene, Janssen, UCB Pharma, Christopher T. Ritchlin Consultant of: Amgen, AbbVie, Eli Lilly, Gilead, Janssen, Novartis, Pfizer and UCB Pharma, Grant/research support from: AbbVie, Amgen and UCB Pharma, Philip J Mease Speakers bureau: AbbVie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer and UCB Pharma, Consultant of: AbbVie, Amgen, BMS, Boehringer Ingelheim, Eli Lilly, Galapagos, Gilead, GSK, Janssen, Novartis, Pfizer, Sun Pharma and UCB Pharma, Grant/research support from: AbbVie, Amgen, BMS, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, Sun Pharma and UCB Pharma, Robert B.M. Landewé Speakers bureau: Abbott, Amgen, BMS, Centocor, Merck, Pfizer, Roche, Schering-Plough, UCB Pharma, and Wyeth, Consultant of: Abbott, Ablynx, Amgen, AstraZeneca, BMS, Centocor, GSK, Novartis, Merck, Pfizer, Roche, Schering-Plough, UCB Pharma, and Wyeth, Grant/research support from: Abbott, Amgen, Centocor, Novartis, Pfizer, Roche, Schering-Plough, UCB Pharma, and Wyeth, Akihiko Asahina Grant/research support from: AbbVie, Amgen, Eisai, Eli Lilly, Janssen, Kyowa Kirin, LEO Pharma, Maruho, Mitsubishi Tanabe Pharma, Pfizer, Sun Pharma, Taiho Pharma, Torii Pharmaceutical, and UCB Pharma, Yoshiya Tanaka Speakers bureau: AbbVie, Amgen, Astellas, AstraZeneca, BMS, Boehringer-Ingelheim, Chugai, Eisai, Eli Lilly, Gilead, Mitsubishi-Tanabe, and YL Biologics, Consultant of: AbbVie, Ayumi, Daiichi-Sankyo, Eli Lilly, GSK, Sanofi, and Taisho, Grant/research support from: Asahi-Kasei, AbbVie, Boehringer-Ingelheim, Chugai, Corrona, Daiichi-Sankyo, Eisai, Kowa, Mitsubishi-Tanabe, and Takeda, Richard B. Warren Paid instructor for: Astellas, DiCE, GSK, and Union, Consultant of: AbbVie, Almirall, Amgen, Arena, Astellas, Avillion, Biogen, BMS, Boehringer Ingelheim, Celgene, Eli Lilly, GSK, Janssen, LEO Pharma, Novartis, Pfizer, Sanofi, and UCB Pharma, Grant/research support from: AbbVie, Almirall, Janssen, LEO Pharma, Novartis, and UCB Pharma, Laure Gossec Consultant of: AbbVie, Amgen, BMS, Galapagos, Gilead, GSK, Janssen, Lilly, Novartis, Pfizer, Samsung Bioepis, Sanofi-Aventis, and UCB Pharma, Grant/research support from: Amgen, Galapagos, Lilly, Pfizer, and Sandoz, Dafna D Gladman Consultant of: AbbVie, Amgen, BMS, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, and UCB Pharma, Grant/research support from: AbbVie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer, and UCB Pharma, Frank Behrens Consultant of: AbbVie, Boehringer Ingelheim, Celgene, Chugai, Eli Lilly, Genzyme, Janssen, MSD, Novartis, Pfizer, Roche, and Sanofi, Barbara Ink Shareholder of: GSK, UCB Pharma, Employee of: UCB Pharma, Deepak Assudani Shareholder of: UCB Pharma, Employee of: UCB Pharma, Rajan Bajracharya Shareholder of: UCB Pharma, Employee of: UCB Pharma, Jason Coarse Shareholder of: UCB Pharma, Employee of: UCB Pharma, Laura Coates Speakers bureau: AbbVie, Amgen, Biogen, Celgene, Eli Lilly, Galapagos, Gilead, GSK, Janssen, Medac, Novartis, Pfizer, and UCB Pharma, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, BMS, Celgene, Eli Lilly, Gilead, Galapagos, Janssen, Moonlake, Novartis, Pfizer, and UCB Pharma, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, Pfizer, and UCB Pharma

Publisher Correction: Exuberant fibroblast activity compromises lung function via ADAMTS4

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Lung γδ T Cells Mediate Protective Responses during Neonatal Influenza Infection that Are Associated with Type 2 Immunity

Compared to adults, infants suffer higher rates of hospitalization, severe clinical complications, and mortality due to influenza infection. We found that γδ T cells protected neonatal mice against mortality during influenza infection. γδ T cell deficiency did not alter viral clearance or interferon-γ production. Instead, neonatal influenza infection induced the accumulation of interleukin-17A (IL-17A)-producing γδ T cells, which was associated with IL-33 production by lung epithelial cells. Neonates lacking IL-17A-expressing γδ T cells or Il33 had higher mortality upon influenza infection. γδ T cells and IL-33 promoted lung infiltration of group 2 innate lymphoid cells and regulatory T cells, resulting in increased amphiregulin secretion and tissue repair. In influenza-infected children, IL-17A, IL-33, and amphiregulin expression were correlated, and increased IL-17A levels in nasal aspirates were associated with better clinical outcomes. Our results indicate that γδ T cells are required in influenza-infected neonates to initiate protective immunity and mediate lung homeostasis.

Targeting Metabolic Reprogramming by Influenza Infection for Therapeutic Intervention

Influenza is a worldwide health and financial burden posing a significant risk to the immune-compromised, obese, diabetic, elderly, and pediatric populations. We identified increases in glucose metabolism in the lungs of pediatric patients infected with respiratory pathogens. Using quantitative mass spectrometry, we found metabolic changes occurring after influenza infection in primary human respiratory cells and validated infection-associated increases in c-Myc, glycolysis, and glutaminolysis. We confirmed these findings with a metabolic drug screen that identified the PI3K/mTOR inhibitor BEZ235 as a regulator of infectious virus production. BEZ235 treatment ablated the transient induction of c-Myc, restored PI3K/mTOR pathway homeostasis measured by 4E-BP1 and p85 phosphorylation, and reversed infection-induced changes in metabolism. Importantly, BEZ235 reduced infectious progeny but had no effect on the early stages of viral replication. BEZ235 significantly increased survival in mice, while reducing viral titer. We show metabolic reprogramming of host cells by influenza virus exposes targets for therapeutic intervention.

ADAMTS4 modulates lung tissue repair following lethal influenza A infection in mice

Lung tissue damage is a major contributor to morbidity and mortality following infection with influenza A virus. Tissue repair, including remodeling of the extracellular matrix (ECM), is a critical process in recovery from infection. A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS) family proteins are secreted zinc metalloendopeptidases and important mediators of ECM remodeling. The role of ADAMTS proteins in lung tissue repair following influenza A infection remains unclear. To investigate the regulation of ADAMTS genes in the context of influenza A infection, we performed a microarray analysis of whole lung homogenates harvested at 24 hours post-infection from B6 mice that were uninfected or infected with mouse-adapted influenza A PR8. In the context of infection, several ADAMTS genes, including ADAMTS4, −6, and −9 exhibited a ≥ 3-fold increase in gene expression compared to uninfected lungs. ADAMTS-4 exhibited the most dramatic increase in gene expression (&gt;100-fold) at this early timepoint. We further investigated the role of ADAMTS4 in survival and recovery from influenza A infection by infecting wild-type (WT) and ADAMTS4 −/− knockout B6 mice with a lethal dose of influenza A PR8. Interestingly, ADAMTS4 −/− mice exhibited significantly improved survival compared to WT littermates (log-rank test, p= 0.04) with 75% vs. 41% survival at 15 days post-infection, despite no observable difference in weight loss. Consistent with a role in tissue repair and recovery, differences in survival were observed after 9 days post-infection. These results raise the possibility that increased expression of ADAMTS4 following influenza A infection modulates the tissue repair process and contributes to lung pathology.

Retinol binding protein and vitamin D associations with serum antibody isotypes, serum influenza virus-specific neutralizing activities and airway cytokine profiles

Vitamin A supports the induction of immunoglobulin (Ig)A responses at mucosal surfaces in mice, but much less is known about the influence of vitamins on antibody isotype expression in humans. To address this knowledge gap, we examined 46 residual blood samples from adults and children, some of whom were experiencing influenza virus infections of the respiratory tract. Assays were performed for retinol binding protein (RBP, a surrogate for vitamin A), vitamin D (a related vitamin) and antibody isotypes. Results showed that all but two tested samples exhibited RBP and/or vitamin D insufficiencies or deficiencies. Vitamin D correlated with blood IgM and IgG3, while RBP correlated with IgG4 and IgA. RBP also correlated positively with age and with influenza virus-specific antibody neutralization titres. Individuals with low blood RBP levels exhibited the highest frequencies of over-expressed cytokines and growth factors in nasal wash samples, an indication of inflamed mucosal tissues. While cause-effect relationships were not discerned, results support a hypothesis that vitamins directly influence B cell isotype expression in humans, and by so doing may help protect mucosal surfaces from respiratory viral disease.

Compromised respiratory function in lethal influenza infection is characterized by the depletion of type I alveolar epithelial cells beyond threshold levels

During influenza virus infection, it is unclear how much alveolar cell loss can be tolerated before the host succumbs to the disease. We sought to define relevant correlates of disease severity in the mouse influenza model, hypothesizing that a susceptibility threshold exists for alveolar epithelial cell loss. We compared lung pathology, virus spread, alveolar epithelial cell depletion, arterial blood oxygenation, physiological responses measured by unrestrained plethysmography, and oxygen consumption and carbon dioxide production by gas analysis in mice at intervals after infection with virus strains and doses that cause mild (x31) or severe (PR/8) influenza. Both mild and severe infections showed similar degrees of lung damage and virus dissemination until day 6 after inoculation but diverged in survival outcomes from day 9. Day 6 PR/8-infected mice had normal respiratory and gas exchange functions with 10% type I cell loss. However, day 10 PR/8-infected mice had 40% type I cell loss with a concomitant drastic decreases in tidal and minute volumes, Vo(2), Vco(2), and arterial blood oxygenation, compared with a maximum 3% type I cell loss for x31 on day 10 when they recovered body weight and respiratory functions. Alterations in breaths per minute, expiratory time, and metabolic rate were observed in both infections. A threshold for maintenance of proper respiratory function appears to be crossed once 10% of alveolar type I cells are lost. These data indicate that lethality in influenza virus infection is a matter of degree rather than quality.