Dysregulated Interferon Response Underlying Severe COVID-19

Round 1

Reviewer 1 Report

In this review article, Lopez et al. has nicely reviewed the dysregulated type I IFN response underly severe COVID-19. This is a urgent and interesting study that summarized the current understanding of Type I/III IFN pathway in the immunopathogenesis upon SARS-CoV-2 infection and the diseases progression, they also proposed important insights on this important research direction. I believe this piece of article will be valuble to the readers and also to the COVID-19 research field. 

I have the following comments that may be helpful to improve the current manuscript.

1. It is generally believed that immune factors constitute the key determinant for COVID-19 severity as evident in myeloid cell dysregulation, lymphopenia, etc. Although innate IFN is the focus of this article, it can be important for the authors to discuss briefly the possible role of other immune factors in the immunopathogenesis of COVID-19. This I believe will significantly improve the breadth of this article.
2. The authors should cite the original paper by Dr. Perlman which firstly linked the dysregulated IFN to SARS pathogenesis, for example, PMC4752723, and some of his review articles. There are a lot of similarities between SARS and SARS-CoV2 while very few specific mechanisms on SARS-CoV-2 are currently discovered.
3. There are several spelling errors. For example, "trial" was written as "trail" in some places.
4. The authors mentioned that "The impaired type I IFN response was characterized by diminished IFN-α/β production by the circulated (should be circulating?) human mononuclear blood cells" through "interfere host IFN signaling".  however, there is no direct evidence of SARS-CoV-2 infection on myeloid cells. The current model of SARS-CoV-2 infection can only explain how the virus antagonizes IFN in ACE2 positive epithelial cells, while the open question here is how the virus dysregulates immune cells (predominantly the myeloid cells). The authors should discuss their potential insights on this important question.
5. The authors proposed their interesting insights on "pre-existing comorbidity or concur a chronic inflammatory condition, their IFN response will be swayed to an immunopathic situation to exacerbate the pneumonia in a severe COVID-19 development. Can the authors elaborate more with regard to what specifically the "chronic inflammatory condiation" could be, and how this can cause an immunopathogenic situation? This are very interesting thoughts and can be helpful to explain disease pathology.
6. The authors also discussed that timing is critical for IFN mediated therapy for COVID-19. They also mentioned "very early stage prior to severe COVID-19 progression", do they mean the timepoint showing any symptoms? It would be difficult to forsee whether patients will progress to severe diseases though.
   
   

Author Response

Reviewer #1:

In this review article, Lopez et al. has nicely reviewed the dysregulated type I IFN response underlying severe COVID-19. This is an urgent and interesting study that summarized the current understanding of Type I/III IFN pathway in the immunopathogenesis upon SARS-CoV-2 infection and the diseases progression, they also proposed important insights on this important research direction. I believe this piece of article will be valuable to the readers and also to the COVID-19 research field.

We highly appreciate for these positive comments.

I have the following comments that may be helpful to improve the current manuscript.

It is generally believed that immune factors constitute the key determinant for COVID-19 severity as evident in myeloid cell dysregulation, lymphopenia, etc. Although innate IFN is the focus of this article, it can be important for the authors to discuss briefly the possible role of other immune factors in the immunopathogenesis of COVID-19. This I believe will significantly improve the breadth of this article.

We thank you for this constructive comment. The follow discussion was added at Line 34-43 with relevant new references (Ref. 13-15) in the revised version:

“Except the pathogenic impact of viral infection, major pathologies underlying severe COVID-19 come from the dysregulation of vast immune factors at both the cellular and molecular levels. For example, severe COVID-19 patients display macrophage overreaction (also known as macrophage activation syndrome (MAS)) and lymphopenias of effective lymphocytes including neutrophils, CD4 T cells, and natural killer (NK) cells [13-15]. At the molecular level, hyper-regulation of proinflammatory mediators (including IL-6, TNFα, S100A8/9 and C-reactive protein), significant decrease of human leukocyte antigen D related (HLA-DR) gene expression in CD14 monocytes, and dysregulated antiviral interferon (IFN) response, have been reported in COVID-19 patients with critical illness [13-15]. In this review, we focus on the determinant role of dysfunctional IFN response underlying the progression of severe COVID-19.”

The authors should cite the original paper by Dr. Perlman which firstly linked the dysregulated IFN to SARS pathogenesis, for example, PMC4752723, and some of his review articles. There are a lot of similarities between SARS and SARS-CoV2 while very few specific mechanisms on SARS-CoV-2 are currently discovered.

Agree, and the suggest original research paper is cited (Ref. 22) together with a most recent review paper per comparative examination of IFN antagonism between SARS-CoV and SARS-CoV2 (Ref. 21).

There are several spelling errors. For example, "trial" was written as "trail" in some places.

Thank you. We conducted proof readings and corrected them.

The authors mentioned that "The impaired type I IFN response was characterized by diminished IFN-α/β production by the circulated (should be circulating?) human mononuclear blood cells" through "interfere host IFN signaling".  however, there is no direct evidence of SARS-CoV-2 infection on myeloid cells. The current model of SARS-CoV-2 infection can only explain how the virus antagonizes IFN in ACE2 positive epithelial cells, while the open question here is how the virus dysregulates immune cells (predominantly the myeloid cells). The authors should discuss their potential insights on this important question.

Thank you for this insightful comment. Although the major ports of SARS-CoV2 infection are ACE2-positive epithelial/endothelial cells, some classes of monocytes and macrophages are ACE2/TMPRSS2 positive (unpublished data) and potentially susceptible to the virus (https://www.biorxiv.org/content/10.1101/2020.09.17.300996v1.full.pdf+html) too. In addition, the virus may antagonize either IFN production signaling in infected cells directly or in surrounding/distant cells indirectly through diminishing the reaction intensity of IFN auto-regulatory loop. The relevant discussion is revised at Line 53-59:

“Studies using transcriptomic analysis in SAR-CoV2 infected human bronchial cells or IFN assays in clinical plasma samples, demonstrated a distinct immune-reaction phenotype in severe and critical patients, being a highly impaired interferon (IFN) response [19-21]. The impaired type I IFN response was characterized by decreased IFN-α/β expression in both SARS-CoV2 infected human bronchial cells and circulating mononuclear blood cells, which was diagnosed together with a persistent viremia and an exacerbated inflammatory response upon reactions to increased pro-inflammatory mediators including tumor necrosis factor–α (TNF-α) and interleukin (IL)-6 [19,20]. ”

The authors proposed their interesting insights on "pre-existing comorbidity or concur a chronic inflammatory condition, their IFN response will be swayed to an immunopathic situation to exacerbate the pneumonia in a severe COVID-19 development. Can the authors elaborate more with regard to what specifically the "chronic inflammatory condition" could be, and how this can cause an immunopathogenic situation? This are very interesting thoughts and can be helpful to explain disease pathology.

Thank you for the constructive suggestion. A further elaboration is added at Line 203-223 with relevant new references (Ref. 64-71)

“Dysregulation of IFNs and other immune factors have been associated with aging, sex difference, and pre-existing medical conditions, which have been clinically associated with a higher risk of severe COVID-19 [10-12,61-63]. Studies showed that both blood and lung dendritic cells (DCs), as a group of major IFN producers, whose capacity in IFN production is severely impaired in aged individuals when compared to juveniles. On the contrary, blood DCs from aged people secreted higher basal levels of proinflammatory cytokines/chemokines including IL-6, TNF-α, CXCL-8, CXCL-10 [64,65]. Together with other aging-associated lympocytic abnormalities [66], this IFN and inflammatory dysregulation in DC response in aged individuals may invoke lung inflammation, impair antiviral resistance and exaggerate major clinical signs as exacerbated in severe COVID-19 [8-12]. For the sex difference of IFN response, studies have demonstrated that plasmacytoid DCs (pDC) from healthy females are more potent to produce type I IFNs via TLR7-mediated signaling than the pDCs from males [67,68]. Plasmacytoid DCs serve as natural IFN producers and efficient sentinels in orchestrating antiviral immunity. This finding implicates an inferior status of males in the early antiviral IFN induction, a suitable stage for most IFN-based clinical trials having positive effect [25]. As for most preexisting medical conditions, including cardiovascular diseases, hypertension, obesity, and diabetes mellitus that increase the risk of severe COVID-19 [61,63], many studies have unraveled the progressive incidence of IFN insensitivity and chronic inflammation and have been reviewed elsewhere [40-42,69-71]. In addition, pathological consequence from persistent IFN and proinflammatory response as well as remarkable presence of auto-Abs represent typical pathological mechanisms underlying most autoimmune diseases including diabetes, multiple sclerosis and systemic lupus erythematosus (SLE) [40-42,69-71].”

The authors also discussed that timing is critical for IFN mediated therapy for COVID-19. They also mentioned "very early stage prior to severe COVID-19 progression", do they mean the timepoint showing any symptoms? It would be difficult to foresee whether patients will progress to severe diseases though.

Agree with the comment, and the sentence is revised at Line 252: “Prophylactic administration of IFNs at the early stage prior to pneumonia progression…”

Reviewer 2 Report

• Lopez et al, provide a review of IFN in COVID-19, this review is useful compilation of clinical and basic research mechanisms of action, such as signalling induction and action, auto antibodies and inborn IFN errors.
• There are some minor English edits needed throughout the text for clarity, e.g. asymptotic -> asymptomatic, “To support this propose” -> To support this proposal (page 3)
• Figure 1 should be revised for clarity, and the legend shortened. The Figure 1 legend could be shortened and explained in the review text with reference to primary research papers to support the IFN pathway relationships, this could be a useful summary of the viral proteins action but without primary papers seems like conjecture in the legend. Figure 1 legend ‘diagramed in the genome and virion structures’ -> diagramed to depicted. Partially diagrammed with Biorender -> Figure made partly with Biorender. Ensure you have the correct license for Biorender for this figure to avoid copyright issues. A-9b/A-3a/A-6, A for ‘Accessory’ protein is unclear, relabel as ORF3a, ORF9b, ORF6. Recolour the proteins to align with the genome depiction , e.g. green for structural proteins throughout.
• The authors reference a study of 50 patients (Hadjadj et al, Science) with a range of COVID-19 severity (ref 13-15), this is a very small sample size, given the earlier sentence of the majority of patients being asymptomatic/mild further support should be given for the impact of IFN on COVID-19 than ref 13. Two other papers are not relevant to this statement, ref 14 (n=24 patients, ferrets and in vitro study) and ref 15 (IFN review).
• The timing of IFN signalling is critical to determine patient outcome, can the authors suggest why some patients are asymptomatic and others spiral to cytokine storm and organ failure? They describe briefly that there is an association of dysregulated IFNa/b with severe COVID, and that type III IFN-l ½ has failed in clinical trials due to timing , but not the reason for dysregulation in some and not other patients beyond inborn errors and auto antibodies, which only account for 14% and 3% of severe cases? Can timing, e.g. acute early versus dysregulated later response, be built into the Figure 1 pathway? And the spatiotemporal effect of IFN therapy?
• The effect of age and gender on IFN signalling is not fully described, can the authors elaborate on the specific effects of these variable on the IFN induction/action pathways?

• Page 1 –In the first paragraph and before going through the details on the IFN sgnalling pathways of IFN type I, please write 2 sentences to specify the different types and subtypes of IFN (α/β/λ/w/g)  . Throughout the review, you are referring to IFNs α/β/λ/w/e/kwithout explaining their differences.

• Page 3: The authors refer to pyroptosis (wrongly spelled pyroptosis) and NETosis, please add a sentence to explain both phenomenons in the context of COVID-19.

• Page 4:

  The authors state the increased susceptibility of lethal bacterial co-infections due to the induction of IFNa/b and IFNlambda 2/3:

  Again IFN Lambda 2/3 need to be clarified, also were these bacterial co-infections reported in severe COVID-19 patients?

  Please use ‘auto-antibodies’ but not ‘auto-reactive antibodies’. In the same sentence “which were instead of targeting the virus but neutralizing against all types…” is wrong. Please clarify the sentence: patients have autoantibodies AND antibodies directed to the virus.

  Instead of “immune-depletion” please use “auto-immune blocking” as it is unclear to the auto-immune process.

  Last paragraph of page 4: “virus infection of blood vessels” are you referring to a proper infection of these cells or to the inflammatory process related to the lung infection ?

   

  Page 5: remove “ obtaining” in “obtaining auto-immune deficiency” it is not scientific, and “acquired” could have been used here. Although as there are no scientific data on whether this auto-immune deficiency is innate or acquired, it is best to avoid it and replace by “auto-immune deficiency”.

  Spatio-temporal kinetics of IFN responses?

  Can the authors give some insights for the authors about the interest of a potential screening for IFN Auto-Abs in patients?

  Regarding inborn genetic IFN disorders: if they are targeting the IFN signalling pathways : the IFN therapies wont be efficient. The authors should specify this.

  IFN drives anti-viral responses in many other viral diseases. In these patients inborn genetic IFN disorders: any previous viral disease with severe progression (flu?...).

  The last sentence of page 5 is unclear, please revise it.

   

  Page 6:

  Auto-immunity is usually related to the women population. Can you please relate this to the observed prevalence of  the anti-IFN auto-antibodies in COVID being higher in the male population.

  Any COVID studies on the percentage of auto-immune comorbidities or common auto-antibodies ?

Author Response

Reviewer #2

Lopez et al, provide a review of IFN in COVID-19, this review is useful compilation of clinical and basic research mechanisms of action, such as signalling induction and action, auto antibodies and inborn IFN errors.

There are some minor English edits needed throughout the text for clarity, e.g. asymptotic -> asymptomatic, “To support this propose” -> To support this proposal (page 3)

Thank you. We conducted proof readings and corrected them.

Figure 1 should be revised for clarity, and the legend shortened. The Figure 1 legend could be shortened and explained in the review text with reference to primary research papers to support the IFN pathway relationships, this could be a useful summary of the viral proteins action but without primary papers seems like conjecture in the legend. Figure 1 legend ‘diagramed in the genome and virion structures’ -> diagramed to depicted. Partially diagrammed with Biorender -> Figure made partly with Biorender. Ensure you have the correct license for Biorender for this figure to avoid copyright issues. A-9b/A-3a/A-6, A for ‘Accessory’ protein is unclear, relabel as ORF3a, ORF9b, ORF6. Recolour the proteins to align with the genome depiction , e.g. green for structural proteins throughout.

Thank you for this constructive comment. The Figure legend is revised, and relevant content is combined in the text at Line 98-128. The figure is redrawn to consistently recolor the viral proteins as recommended without a copyright issue. 

The authors reference a study of 50 patients (Hadjadj et al, Science) with a range of COVID-19 severity (ref 13-15), this is a very small sample size, given the earlier sentence of the majority of patients being asymptomatic/mild further support should be given for the impact of IFN on COVID-19 than ref 13. Two other papers are not relevant to this statement, ref 14 (n=24 patients, ferrets and in vitro study) and ref 15 (IFN review).

Agree. The relevant discussion is revised at Line 53-72 to reflect more accurately as in the references (now Ref. 19-21), and new references (Ref. 26,27) for recent GWAS using large patient cohorts:

“Studies using transcriptomic analysis in SAR-CoV2-infected human bronchial cells or IFN assays in clinical plasma samples, demonstrated a distinct immune-reaction phenotype in symptomatic COVID-19 patients, being a highly impaired interferon (IFN) response [19,20]. The impaired type I IFN response was characterized by decreased IFN-α/β expression in both SARS-CoV2 infected human bronchial cells and circulating mononuclear blood cells, which was diagnosed together with a persistent viremia and an exacerbated inflammatory response upon reactions to increased pro-inflammatory mediators including tumor necrosis factor–α (TNF-α) and interleukin (IL)-6 [19,20]. Together with other previously in vitro studies, these data suggest that SARS-CoV2 bears similar antagonistic mechanisms as other severe human coronaviruses (i.e. SARS and MERS) to interfere with the host IFN signaling, especially the production of type I IFNs (Figure 1) [21,22]. In contrast, other studies by Lee et al. (2020) and Lucas et al. (2020) detected that patients with severe COVID-19 had a sustained type I IFN response and consistent proinflammatory response in the blood of patients subjected to severe COVID-19 [23,24]. Contradictory results about type I IFN responses in COVID19 patients may come from the disparity of criteria to define disease severity and different sampling times during the disease progression [25]. In addition, using large cohorts of COVID-19 patients in European countries, recent genome-wide associated studies (GWAS) have significantly associated several critical genetic loci with severe COVID-19, which contain genetic regions spanning multiple genes that are centered in both chemokine and IFN signaling [26,27]. All these studies highlight the potential role of IFN signaling in determining the host susceptibility to SARS-CoV2 infection and the progression of severe COVID-19 [19-27].”

The timing of IFN signalling is critical to determine patient outcome, can the authors suggest why some patients are asymptomatic and others spiral to cytokine storm and organ failure? They describe briefly that there is an association of dysregulated IFNa/b with severe COVID, and that type III IFN-l ½ has failed in clinical trials due to timing , but not the reason for dysregulation in some and not other patients beyond inborn errors and auto antibodies, which only account for 14% and 3% of severe cases? Can timing, e.g. acute early versus dysregulated later response, be built into the Figure 1 pathway? And the spatiotemporal effect of IFN therapy?

Thank you for this constrictive comment but challenging given the limited spatiotemporal data about IFN response. We modified the Figure 1 to address it hopefully in general. In brief, the canonical IFN signaling flow, which acts generally at early stage of SARS-CoV2 infection for primarily restricting viral infection, is depicted using black arrows; and brown arrows indicating the non-canonical IFN signaling flow, which is highly associated with pro-inflammation and immunopathies at the later stage or severe COVID-19 progression.

The effect of age and gender on IFN signalling is not fully described, can the authors elaborate on the specific effects of these variable on the IFN induction/action pathways?

Thank you for the constructive suggestion. A further elaboration is added at Line 203-223 with relevant new references (Ref. 64-71)

“Dysregulation of IFNs and other immune factors have been associated with aging, sex difference, and pre-existing medical conditions, which have been clinically associated with a higher risk of severe COVID-19 [10-12,61-63]. Studies showed that both blood and lung dendritic cells (DCs), as a group of major IFN producers, whose capacity in IFN production is severely impaired in aged individuals when compared to juveniles. On the contrary, blood DCs from aged people secreted higher basal levels of proinflammatory cytokines/chemokines including IL-6, TNF-α, CXCL-8, CXCL-10 [64,65]. Together with other aging-associated lympocytic abnormalities [66], this IFN and inflammatory dysregulation in DC response in aged individuals may invoke lung inflammation, impair antiviral resistance and exaggerate major clinical signs as exacerbated in severe COVID-19 [8-12]. For the sex difference of IFN response, studies have demonstrated that plasmacytoid DCs (pDC) from healthy females are more potent to produce type I IFNs via TLR7-mediated signaling than the pDCs from males [67,68]. Plasmacytoid DCs serve as natural IFN producers and efficient sentinels in orchestrating antiviral immunity. This finding implicates an inferior status of males in the early antiviral IFN induction, a suitable stage for most IFN-based clinical trials having positive effect [25]. As for most preexisting medical conditions, including cardiovascular diseases, hypertension, obesity, and diabetes mellitus that increase the risk of severe COVID-19 [61,63], many studies have unraveled the progressive incidence of IFN insensitivity and chronic inflammation and have been reviewed elsewhere [40-42,69-71]. In addition, pathological consequence from persistent IFN and proinflammatory response as well as remarkable presence of auto-Abs represent typical pathological mechanisms underlying most autoimmune diseases including diabetes, multiple sclerosis and systemic lupus erythematosus (SLE) [40-42,69-71].”

Page 1 –In the first paragraph and before going through the details on the IFN sgnalling pathways of IFN type I, please write 2 sentences to specify the different types and subtypes of IFN (α/β/λ/w/g)  . Throughout the review, you are referring to IFNs α/β/λ/w/e/kwithout explaining their differences.

Thank you for the comment. The following description is added at Line 46-51:

“The IFN molecules of three IFN types are further designated into subtypes, which include the single IFN-γ for type II and IFN-λ1-4 for type III such as in humans. There are multiple subtypes of type I IFNs, which include general subtypes of IFN-α and IFN-β produced by most cells, and more cell-specific subtypes including IFN-ε (reproductive tract), IFN-κ (keratinocytes), IFN-ω (leukocytes/epithelia), and species-specific subtypes of IFN-δ (pigs), IFN-τ (cattle) and IFN-ξ (mice) [16-18].”

Page 3: The authors refer to pyroptosis (wrongly spelled pyroptosis) and NETosis, please add a sentence to explain both phenomenons in the context of COVID-19.

Thank you for the indication. The sentence is revised with the definitions of pyroptosis and NETosis at Line 118-123:

“The non-canonical IFN signaling, for that responding to pDNA through cGAS-STING and non-canonical ISG stimulation via IFN-TNF epigenetic coordination might occur at the latter stage accompanying massive cell death from pyroptosis (a highly inflammatory form of programmed cell death in infected cells) and NETosis (an immunologically regulated form of neutrophil cell death) as seen in severe COVID19 cases [16-18,33-38].”

Page 4: The authors state the increased susceptibility of lethal bacterial co-infections due to the induction of IFNa/b and IFNlambda 2/3:

Again IFN Lambda 2/3 need to be clarified, also were these bacterial co-infections reported in severe COVID-19 patients?

The four IFN-λ genes of type III IFNs were clarified at Line 46-51, and further defined as type III IFN-λ at Line 149. Yes, bacterial co-infection have been reported in COVID-19, and particularly common (8.1%) in severe COVID-19 patients. The following sentence is added at Line 160-163:

“Indeed, a meta-analysis evaluated 4.3-9.5% of COVID-19 patients with bacterial infection, which was more common in severe patients (8.1%) [47]; so were incidences of co-infection from other microbes including fungi and other viruses in critically ill COVID-19 patients, who suffer dysfunctional IFN and other immune reaction [48] “

Please use ‘auto-antibodies’ but not ‘auto-reactive antibodies’. In the same sentence “which were instead of targeting the virus but neutralizing against all types…” is wrong. Please clarify the sentence: patients have autoantibodies AND antibodies directed to the virus.

Thank you, and it is corrected. The sentence is rewritten at Line 181-184:

“In this case, they detected 101 of 987 (10.2%) patients with life-threatening COVID-19 pneumonia had auto-antibodies (auto-Abs), which were capable of binding and functionally blocking out almost all subtypes of type I IFNs, particularly of IFN-α, IFN-ω, and both IFN-α/ω subtypes, in further antiviral regulation [52].”

Instead of “immuno-depletion” please use “auto-immune blocking” as it is unclear to the auto-immune process.

Changed as suggested at Line 193.

Last paragraph of page 4: “virus infection of blood vessels” are you referring to a proper infection of these cells or to the inflammatory process related to the lung infection ?

We infer both, but more specifically to the direct infection in endothelial cells as referred (Ref. 79,80). The sentence is revised at Line 223-226:

“The dysregulation of IFN and other immune factors in the COVID-19 patients with pre-existing comorbidities, could be further complicated by the virus attacking on endothelial cells to cause vasculitis, aneurysms and coagulopathy as well as tissue damage in the kidney, heart and even brain [72-75].”

 Page 5: remove “ obtaining” in “obtaining auto-immune deficiency” it is not scientific, and “acquired” could have been used here. Although as there are no scientific data on whether this auto-immune deficiency is innate or acquired, it is best to avoid it and replace by “auto-immune deficiency”.

Thank you. It is corrected as suggested at Line 231.

Spatio-temporal kinetics of IFN responses?

It is revised at Line 236:

“…based on the temporal characteristics and subtype-specificity of IFN responses during SARS-CoV2 infection and the disease progression.”

Can the authors give some insights for the authors about the interest of a potential screening for IFN Auto-Abs in patients?

Very insightful suggestion. It is a little beyond the scope of this review, and actually it was partially described and referred by the research methods in Ref. 52. 

Regarding inborn genetic IFN disorders: if they are targeting the IFN signalling pathways : the IFN therapies wont be efficient. The authors should specify this.

Thank you for this constructive comment. We added the relevant description at Line 278-282:

“It is noteworthy that all designed IFN therapies, which are based on normal IFN signaling, will be not properly functional in individuals who have inborn genetic or auto-immune deficiency of IFN system [52,53]. This will demand for early diagnosis of this kind of genetic and auto-Ab errors in potential and hospitalized patients who are irresponsive to IFN-based treatments [27,52,53].”    

IFN drives anti-viral responses in many other viral diseases. In these patients inborn genetic IFN disorders: any previous viral disease with severe progression (flu?...).

Yes. Inborn genetic disorders in IFN signaling have been associated to HIV and other viral infections, and some autoimmune diseases. Please refer to the Ref. 53 and 54 and references therein for further information.

The last sentence of page 5 is unclear, please revise it.

Thank you. It is revised at Line 234-237:

“Hence, the prophylactic or therapeutic effect of IFN trial regimens should be carefully designed based on the temporal characteristics and subtype-specificity of IFN responses during SARS-CoV2 infection and the disease progression [25,49,50,53,54,76]”

Page 6: Auto-immunity is usually related to the women population. Can you please relate this to the observed prevalence of the anti-IFN auto-antibodies in COVID being higher in the male population.

It raises an intricating situation to address, and probably has no clear answer. Although some types of autoimmune diseases such as SLE are more related to the female, our conjecture for the prevalence of anti-IFN auto-Abs in males with severe COVID-19 is that the IFN-mediated immune homeostasis in the male is more vulnerable in the complication of SARS-CoV2 infection and accompanying hyperinflammation. On the other words, women may acclimate a higher threshold of IFN-mediated immune homeostasis due to a more robust IFN response in women as described (Ref. 67,68)   

Any COVID studies on the percentage of auto-immune comorbidities or common auto-antibodies ?

Not conclusively to our knowledge, but some useful estimation may referable in reference 82,83, and others as examples below:

Favalli EG, Ingegnoli F, De Lucia O, Cincinelli G, Cimaz R, Caporali R. COVID-19 infection and rheumatoid arthritis: Faraway, so close! Autoimmun Rev. 2020 May;19(5):102523.

Joob B, Wiwanitkit V. SLE, hydroxychloroquine and no SLE patients with COVID-19: a comment. Ann Rheum Dis. 2020 Jun;79(6):e61.

Horisberger A, Moi L, Ribi C, Comte D. Impact of COVID-19 pandemic on SLE: beyond the risk of infection. Lupus Sci Med. 2020 May;7(1):e000408.

Singh AK, Gupta R, Ghosh A, Misra A. Diabetes in COVID-19: Prevalence, pathophysiology, prognosis and practical considerations. Diabetes Metab Syndr. 2020 Jul-Aug;14(4):303-310.

Reviewer 3 Report

this interesting article discusses the dysregulation of the interferon response in the pathogenesis of severe covid 19
however interesting, in my opinion, the paper needs a part that explains how the alteration of the interferonic response influences the pathogenesis in the cytokine storm (see  10.1016/j.jinf.2020.03.037)and what can be the clinical implications respect to studies on interleukin inhibitors or JAk STAT inhibitors (see 10.12998/wjcc.v8.i19.4280 )

Author Response

Reviewer #3

this interesting article discusses the dysregulation of the interferon response in the pathogenesis of severe covid 19. however interesting, in my opinion, the paper needs a part that explains how the alteration of the interferonic response influences the pathogenesis in the cytokine storm (see  10.1016/j.jinf.2020.03.037) and what can be the clinical implications respect to studies on interleukin inhibitors or JAk STAT inhibitors (see 10.12998/wjcc.v8.i19.4280 ).

Thank you for the positive comment. The intersection of IFN and pro-inflammatory signaling has been reviewed elsewhere (Ref. 27). We add the following discussion to discuss the association of IFN dysfunction and relevant hyperinflammation in severe COVID-19 at Line 35-43:

“For example, severe COVID-19 patients display macrophage overreaction (also known as macrophage activation syndrome (MAS)) and lymphopenias of effective lymphocytes including neutrophils, CD4 T cells, and natural killer (NK) cells [13-15]. At the molecular level, hyper-regulation of proinflammatory mediators (including IL-6, TNFα, S100A8/9 and C-reactive protein), significant decrease of human leukocyte antigen D related (HLA-DR) gene expression in CD14 monocytes, and dysregulated antiviral interferon (IFN) response, have been reported in COVID-19 patients with critical illness [13-15]. In this review, we focus on the determinant role of dysfunctional IFN response underlying the progression of severe COVID-19.”

In addition, the clinical implications respect to studies on interleukin inhibitors or JAk STAT inhibitors are applicable to the adverse side of dysregulated IFN response, which are devised to mitigate the pathological IFN and pro-inflammatory response sustained in severe COVID-19. We brief this point in the Section 5 at Line 259-261 with new reference 79-81:

“By contrast, clinical trials of relevant IL-6, TNF, and JAk STAT inhibitors are applicable to the adverse side of dysregulated IFN response, which are devised to mitigate the pathological IFN and pro-inflammatory response sustained in severe COVID19 [79-81].”

Round 2

Reviewer 3 Report

the authors have implemented the paper.

correctly they used colors for the figures to make them clearer.

The authors are not in agreement in dedicating a paragraph on the role of the intersection of the cytokinic storm and  interferon response , but they are satisfy to add some sentences.
They also use citations 79-80 which do not seem totally appropriate in this context, while they may use those suggested (10.1016 / j.jinf.2020.03.037 and 10.12998 / wjcc.v8.i19.4280) or others they deem more appropriate.

Author Response

#Review 3-2nd

The authors are not in agreement in dedicating a paragraph on the role of the intersection of the cytokinic storm and  interferon response , but they are satisfy to add some sentences.

They also use citations 79-80 which do not seem totally appropriate in this context, while they may use those suggested (10.1016 / j.jinf.2020.03.037 and 10.12998 / wjcc.v8.i19.4280) or others they deem more appropriate.

Agree. However, extensive discussion of cytokine release syndrome (CRS) or “cytokine storm” is not a focus of this review. Further discussion of cytokine release relevant IFN dysfunction in severe COVID-19 is added at Line 35-43:

“For example, severe COVID-19 patients display macrophage overreaction (also known as macrophage activation syndrome (MAS)) and lymphopenias of effective lymphocytes including neutrophils, CD4 T cells, and natural killer (NK) cells [13-15]. At the molecular level, hyper-regulation of proinflammatory mediators (including IL-6, TNFα, S100A8/9 and C-reactive protein), significant decrease of human leukocyte antigen D related (HLA-DR) gene expression in CD14 monocytes, and dysregulated antiviral interferon (IFN) response, have been reported in COVID-19 patients with critical illness [13-15]. In this review, we focus on the determinant role of dysfunctional IFN response underlying the progression of severe COVID-19.”

And further discussed at Line 259-266 with new reference 79-81:

“Interferon signaling has intricating crosstalk with multiple inflammatory cytokines including TNF-α, IL-6, because they intersect in using some common intracellular signaling components [16,27]. In this context, prophylactic effect of early IFN application may actually mitigate the CRS through the antiviral and anti-inflammatory effect of some epithelial specific IFN subtypes. However, extensive validation of subtype-specific activity is warranted for a better optimization of IFN clinical uses [79-81].  By contrast, clinical trials of relevant IL-6, TNF, and JAK STAT inhibitors and blocking antibodies are applicable to the adverse side of dysregulated IFN response, which are devised to mitigate the pathological IFN and pro-inflammatory response sustained in severe COVID19 [79-81].”

The suggested two following references are used to replace the previous 79 and 80:

Ye Q, Wang B, Mao J. The pathogenesis and treatment of the `Cytokine Storm' in COVID-19. J Infect. 2020 Jun;80(6):607-613.

Ucciferri C, Vecchiet J, Falasca K. Role of monoclonal antibody drugs in the treatment of COVID-19. World J Clin Cases. 2020 Oct 6;8(19):4280-4285.