Mycoplasma mycoides subsp. mycoides (Mmm), a pathogenic wall-less bacterium, is the etiological agent of contagious bovine pleuropneumonia (CBPP). This highly contagious respiratory disease may develop in severe pneumonia, with associated high mortality rates in cattle. Mmm can display different immune evasion mechanisms; in addition, a host uncontrolled inflammatory response stands for lung lesions and chronic carrier animals.
Macrophages are among the most important lines of defense against Mmm of the lower respiratory tract. Although their importance in defense and immune response modulation is known, results about their role and mechanisms of action are scarce and sometimes conflicting.
In the present study, Totté et al. (1) aimed to investigate the interaction of bovine macrophages (isolated from cattle peripheral blood mononuclear cells) with Mmm, under in vitro conditions. The authors highlight that the study was performed under physiological conditions (in the presence of complement prepared from the same cell donor).
In their study, using different approaches, the authors provide interesting and original results, proposing a pivotal role of complement in controlling the inflammatory response, which is crucial in the CBPP pathogenesis.
The authors reported that macrophages did not kill Mmm in the presence of a non-bactericidal concentration of bovine serum. However, Mmm inactivation was observed when antiserum from CBPP convalescent animals was used. They also observed that Mmm induced the production of TNF by macrophages (when a high MOI was assessed). However, complement could even abolish Mmm-induced TNF response when used at bactericidal activity concentrations. This role of complement could be combined with the development of potentially protective antibodies against particular Mmm antigens involved in the interaction with identified macrophage receptors to propose control strategies against CBPP.
Overall, the study by Totté et al. provides new fundamental insight for the research on preventive or therapeutic strategies for a poorly understood disease that still represents a serious concern for livestock production.
1. Totté, P., Bonnefois, T., Manso-Silván, L. Interactions between Mycoplasma mycoides subsp. mycoides and bovine macrophages under physiological conditions. bioRxiv 2022.12.06.519279, ver. 2 peer-reviewed and recommended by Peer Community In Microbiology. https://doi.org/10.1101/2022.12.06.519279
DOI or URL of the preprint: https://doi.org/10.1101/2022.12.06.519279
Version of the preprint: 1
Two Reviewers have evaluated your article. As you can see, both of them have recognized the scientific merit of your work (which I agree), although they have some concerns, comments, and suggestions to be addressed before recommendation (please see comments below).
Also, please take into account these few comments of my own:
I noticed that there is a dead link at the end of Totté et al. ms. on BioRxiv, in the "Data, scripts, code, and supplementary information availability" section: "Supplementary File1 is available online: XXXXDOI of the webpage hosting the data https://doi.org/10.5802/fake.doi"
It must be clear whether this "Supplementary File1" refers to the supplementary figure available on the BioRxiv page (i.e. https://www.biorxiv.org/content/10.1101/2022.12.06.519279v1.supplementary-material) or if it refers to the data used for the study and available on Zenodo (i.e. https://doi.org/10.5281/zenodo.7442581)
In any case, you must clarify this and give the correct web address in the manuscript. The link to the data must be available in the manuscript.
The surname of the first author must be Totté (not totté).
In the section “Data, scripts, code, and supplementary information availability,” the authors refer to a “Supplementary File1,” but it is not cited in the text; please clarify.
Please consider the inclusion of additional references that could enhance the scientific support of the study.