scholarly journals Cross-Reactivity and Functionality of Approved Human Immune Checkpoint Blockers in Dogs

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 785
Author(s):  
Stanislav Pantelyushin ◽  
Elisabeth Ranninger ◽  
Diego Guerrera ◽  
Gregor Hutter ◽  
Caroline Maake ◽  
...  

Background: Rodent cancer models have limitations in predicting efficacy, tolerability and accompanying biomarkers of ICIs in humans. Companion dogs suffering from neoplastic diseases have gained attention as a highly relevant translational disease model. Despite successful reports of PD-1/PD-L1 blockade in dogs, no compounds are available for veterinary medicine. Methods: Here, we assessed suitability of seven FDA-approved human ICIs to target CTLA-4 or PD-1/PD-L1 in dogs. Cross-reactivity and blocking potential was assessed using ELISA and flow cytometry. Functional responses were assessed on peripheral blood mononuclear cells (PBMCs) derived from healthy donors (n = 12) and cancer patient dogs (n = 27) as cytokine production after stimulation. Immune composition and target expression of healthy donors and cancer patients was assessed via flow cytometry. Results: Four candidates showed cross-reactivity and two blocked the interaction of canine PD-1 and PD-L1. Of those, only atezolizumab significantly increased cytokine production of healthy and patient derived PBMCs in vitro. Especially lymphoma patient PBMCs responded with increased cytokine production. In other types of cancer, response to atezolizumab appeared to correlate with a lower frequency of CD8 T cells. Conclusions: Cross-functionality of atezolizumab encourages reverse translational efforts using (combination) immunotherapies in companion dog tumor patients to benefit both veterinary and human medicine.

1998 ◽  
Vol 21 (5) ◽  
pp. 269-273 ◽  
Author(s):  
B.L. Jaber ◽  
S. Sundaram ◽  
M. Cendoroglo Neto ◽  
A.J. King ◽  
B.J.G. Pereira

Gram-negative bacterial lipopolysaccharide (LPS) is a well known stimulus for cytokine production, particularly interleukin-1 (IL-1) and tumor necrosis tactor alpha (TNFα). Polymyxin B (PMX-B) is a cationic polypeptide that binds to LPS, neutralizing its biological effects. PMX-B also disrupts gram-negative bacterial cell membrane phospholipids but is highly toxic to mammalian cells, therefore is of limited use. PMX-B is used as additive to media, as a way to handle LPS contamination. To derive benefit from the ability of PMX-B to neutralize lipid A in vivo while avoiding its systemic toxicity, PMX-B was covalently bound to polystyrene-derivative fibers, creating a hemoperfusion column (PMX-F) for the selective removal of circulating ET In vitro PMX-F hemoperfusion studies have demonstrated effective ET removal, using either the Limulus amebocyte lysate assay or TNFα production by peripheral blood mononuclear cells (PBMC) as an index of ET removal. However, the question whether PMX-B itself could stimulate human PBMC to produce cytokines has not been adequately addressed. We examined the effect of increasing concentrations of PMX-B on cytokine production by PBMC in vitro. PBMC harvested from healthy volunteers were incubated for 24 hours at 37°C with control (tissue culture media RPMI), or 5 µg/ml, 10 µg/ml, 20 µg/ml or 100 µg/ml PMX-B. At the end of 24 hours, PBMC were subjected to three freeze-thaw cycles, and total TNFα production (pg/2.5x106 PBMC) was measured by radioimmunoassay. Total TNFα production by PBMC was 163 ± 3 pg, 171 ± 9 pg, 164 ± 4 pg, 323 ± 63 pg and 331 ± 58 pg, in the control, PMX-B 5 µg/ml, 10 µg/ml, 20 µg/ml and 100 µg/ml conditions, respectively. Compared to controls (RPMI), the percentage increase in TNFα production by PBMC was 5 ± 6% (P=0.23), 1 ± 3% (P=0.45), 99 ± 40% (P=0.03) and 103 ± 36% (P=0.02) in the presence of 5 µg/ml, 10 µg/ml, 20 µg/ml and 100 µg/ml of PMX-B, respectively. Furthermore, total TNFα production correlated significantly with increasing concentrations of PMX-B (R=0.53, P=0.007). We conclude that the use of PMX-B in in vitro studies as an LPS-neutralizing agent, or in the experimental treatment of endotoxic or septic shock can lead to erroneous interpretations of cytokine production by PBMC, and should be used cautiously in in vitro systems at high concentrations.


Blood ◽  
1989 ◽  
Vol 74 (8) ◽  
pp. 2713-2717 ◽  
Author(s):  
W Hinterberger ◽  
G Adolf ◽  
P Bettelheim ◽  
K Geissler ◽  
C Huber ◽  
...  

Abstract The production of interferons (IFNs), IFN-gamma, tumor necrosis factors (TNFs) and TNF-alpha (TNF-alpha) by peripheral blood mononuclear cells (PBMNCs) of untransfused and transfused, but otherwise untreated patients with severe aplastic anemia (SAA) was determined using bioassays and immunoassays. In untransfused and pretransfused SAA patients, spontaneous and lectin-induced production of these cytokines by PBMNCs was strongly enhanced. Cytokine production in untransfused SAA patients did not differ from that in pretransfused patients. Similar relative frequencies of activated (HLA-DR+) lymphocyte subpopulations present in the PBMNCs demonstrated cytokine overproduction per cells. Cytokine production was studied in three SAA patients before and after blood cell transfusions. Spontaneous and lectin-induced production of these cytokines was abnormally high and unaffected by blood transfusions. In another patient exhibiting abnormal cytokine production, the hematopoietic response to cyclosporin- A in vivo was accompanied by normalization of cytokine production in vitro. We conclude that overproduction of IFN-gamma and TNF-alpha by lectin-stimulated PBMNCs is an intrinsic abnormality of SAA unrelated to blood transfusions. Normalization of production of IFN-gamma and TNF- alpha accompanying a clinical response to cyclosporin-A may cautiously be taken as further evidence suggesting a pathogenetic role of cytokine overproduction in SAA.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Carolina V. Messias ◽  
Julia P. Lemos ◽  
Daniela P. Cunha ◽  
Zilton Vasconcelos ◽  
Lidiane M. S. Raphael ◽  
...  

Abstract Background Zika virus (ZIKV) infection gained public health concern after the 2015 outbreak in Brazil, when microcephaly rates increased in babies born from infected mothers. It was demonstrated that ZIKV causes a congenital Zika virus syndrome, including various alterations in the development of the central nervous system. Although the infection of cells from the nervous system has been well documented, less is known in respect of ZIKV ability to infect immune cells. Herein, we investigated if peripheral blood mononuclear cells (PBMCs), freshly-isolated from healthy donors, could be infected by ZIKV. Methods PBMCs from healthy donors were isolated and cultured in medium with ZIKV strain Rio-U1 (MOI = 0.1). Infection was analyzed by RT-qPCR and flow cytometry. Results We detected the ZIKV RNA in PBMCs from all donors by RT-qPCR analysis. The detection of viral antigens by flow cytometry revealed that PBMC from more than 50% the donors were infected by ZIKV, with CD3+CD4+ T cells, CD3−CD19+ B cells and CD3+CD8+ T cells being, respectively, the most frequently infected subpopulations, followed by CD14+ monocytes. Additionally, we observed high variability in PBMC infection rates among different donors, either by numbers or type infected cells. Conclusions These findings raise the hypothesis that PBMCs can act as a reservoir of the virus, which may facilitate viral dissemination to different organs, including immune-privileged sites.


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