DOI: 10.5061/dryad.0gb5mkmcb
title: Disease severity in coinfected hosts: the importance of infection order

description: When hosts are simultaneously infected by different pathogens, the
 severity of the disease might be exacerbated compared to hosts harboring
 single infections. The reasons underlying these changes in parasite
 virulence are manifold. Here, we investigated the importance for the
 infection outcome of order and timing of infection. We used a model of
 rodent coinfection between two parasites that do not compete for common
 resources, an intestinal nematode (Heligmosomoides polygyrus) and an
 apicomplexan protozoan (Plasmodium yoelii). During single infections, H.
 polygyrus induced only mild disease symptoms. Plasmodium produced a
 substantial reduction in the number of red blood cells, but all mice
 recovered from the infection. A different picture emerged in coinfected
 hosts. Heligmosomoides maintained a profile of mostly asymptomatic
 infection whatever the order of the infection (first or second). On the
 contrary, P. yoelii incurred substantially higher costs in hosts that had
 been previously infected with H. polygyrus (independently of the timing of
 infection). We then investigated the possible reasons underlying the
 increase of Plasmodium virulence in coinfected hosts. We found that
 coinfected hosts were less able to control Plasmodium multiplication and
 to recover from infection-induced anemia. Coinfected hosts had similar
 levels of erythropoietin and similar renewal of lost red blood cells,
 resulting in decreased tolerance to Plasmodium infection. Experimental
 administration of erythropoietin in coinfected hosts, partially decreased
 the severity of disease symptoms and improved tolerance. The
 detoxification of free heme released during the lysis of red blood cells,
 and the expression of Th1 and anti-inflammatory cytokine genes were also
 similar between coinfected and single infected hosts. However, coinfected
 mice had higher proportions of regulatory T cells expressing the CTLA-4
 immune checkpoint, suggesting an enhanced immunosuppressive activity of T
 regs. Plasmodium infection also induced the exhaustion of CD8+T cells, as
 coinfected mice had higher proportions of both PD-1+and LAG-3+CD8+T cells,
 and an increase in the CD4+/CD8+ratio. Overall, these results stress the
 importance of the order of infection as a major determinant of disease
 severity in coinfected hosts. We discuss the possible epidemiological and
 evolutionary consequences of these results.
description: # Disease severity in coinfected hosts: the importance of infection order
 [Access this dataset on Dryad](https://doi.org/10.5061/dryad.0gb5mkmcb)
 This dataset reports the raw data collected during an experiment where
 hosts (mice) were infected with two parasites (the nematode
 Heligmosomoides polygyrus and the protozoan Plasmodium yoelii). In the
 experiment, hosts were infected according to different orders and timings
 of infection with the aim of exploring the effect of these two traits on
 the severity of the disease. During the experiment, we collected several
 variables referring to the general costs of infection (host body mass,
 host spleen mass, host plasma levels of aspartate aminotransferase, host
 survival), Plasmodium yoelii parasitemia, specific costs due to the
 infection with Plasmodium yoelii (host red blood cell counts, host plasma
 levels of erythropoietin, host mean globular volume), host tolerance to
 the infection with Plasmodium yoelii, host capacity to scavenge the heme
 group released during the lysis of red blood cells (host Hmox1 gene
 expression, host plasma levels of the enzyme HO-1, host proportion of red
 pulp macrophages that expressed the receptor CD163), host immune response
 (gene expression of the cytokines IFN-g, IL-10, TGF-b, host proportion of
 Treg cells among CD4+ lymphocytes, host proportion of Treg cells that
 expressed the CTLA-4 immune checkpoint, host proportions of 20 immune cell
 populations, host proportion of Th2 cells among CD4+ lymphocytes, host
 proportion of CD8+ lymphocytes among CD3+ cells, host proportion of CD8+
 lymphocytes expressing the CTLA-4, PD-1, LAG-3 immune checkpoints),
 correlation between the CD4+/CD8+ ratio and host mortality. In addition,
 we ran a second experiment where hosts (mice) where treated with
 erythropoietin with the aim of investigating how this might change disease
 severity. In this experiment, we collected the following variables : host
 body mass, host red blood cell counts, host survival, host tolerance to
 the infection with Plasmodium yoelii. The data have been organized in
 separate .xlsx files, one file per variable. For instance, the file named
 "1_data_on_body_mass" reports the data referring to the host
 body mass. Since we ran multiple statistical models for each variable,
 that included different experimental groups, data files contain multiple
 sheets each referring to one statistical model. For instance the file
 named "1_data_on_body_mass" contains 6 sheets. The first sheet
 corresponds to the statistical model where we compared body mass of
 non-infected hosts and hosts that were single infected; the second sheet
 corresponds to the model where we compared body mass of hosts that were
 single infected with Plasmodium yoelii and hosts that were coinfected with
 Plasmodium yoelii and Heligomosmoides polygyrus (the experimental group
 that was simultaneously infected and the groups that were first infected
 with Heligmosomoides polygyrus and then with Plasmodium yoelii); the third
 sheet corresponds to the model where we compared body mass of hosts that
 were single infected with Heligomosmoides polygyrus and hosts that were
 coinfected with Plasmodium yoelii and Heligomosmoides polygyrus (the
 experimental groups that were first infected with Plasmodium yoelii and
 then with Heligmosomoides polygyrus); the forth sheet corresponds to the
 model where we compared the body mass of non-infected hosts, single
 Plasmodium yoelii infected hosts and coinfected hosts (the experimental
 group that was simultaneously infected and the groups that were first
 infected with Heligmosomoides polygyrus and then with Plasmodium yoelii
 LUMPED TOGETHER); the fifth sheet corresponds to the model where we
 compared the body mass of non-infected hosts, single Heligmosomoides
 polygyrus infected hosts and coinfected hosts (the experimental groups
 that were first infected with Plasmodium yoelii and then with
 Heligmosomoides polygyrus LUMPED TOGETHER); the sixth sheet corresponds to
 the model where we compared the body mass of hosts that were first
 infected with Heligmosoides polygyrus and then with Plamsodium yoelii and
 hosts that were first infected with Plasmodium yoelii and then with
 Heligmosomoides polygyrus. Data files have been numbered according to the
 order of appearance in the result section of the corresponding article.
 That is, the first result reported in the article deals with body mass and
 for this reason the data file has been numbered
 "1_data_on_body_mass". We also provide the code files that have
 been used to analyse the data and produce the figures. These .txt files
 have been numbered as for the data files, so the file
 "1_code_body_mass" corresponds to the code used to analyse the
 data reported in the file "1_data_on_body_mass". ## Description
 of the data and file structure Here we describe the variables in each data
 file (with the associated code file) ### 1_data_on_body_mass (associated
 to 1_code_body_mass) mouse_id : the identity of the mouse replicate : the
 identity of the replicated dataset (1 or 2) time_post_infection : the time
 post infection in days (for coinfected groups this refers to time post
 second infection) percent_variation_body_mass : Percent variation in body
 mass (g) with respect to day 0 for control, single infected and the
 simultaneous infection group and with respect to the day of the second
 infection for the other coinfection groups Treatment : non-infected =
 control individuals single Hp = single infection with Heligmosomoides
 polygyrus single Py = single infection with Plasmodium yoelii Hp+Py =
 simultaneous infection with the two parasites Hp-7+Py = first infection
 with Heligmosomoides polygyrus and after 7 days second infection with
 Plasmodium yoelii Hp-28+Py = first infection with Heligmosomoides
 polygyrus and after 28 days second infection with Plasmodium yoelii
 Py-14+Hp = first infection with Plasmodium yoelii and after 14 days second
 infection with Heligmosomoides polygyrus Py-28+Hp = first infection with
 Plasmodium yoelii and after 28 days second infection with Heligmosomoides
 polygyrus coinfected (simultaneous and Hp first) = Hp+Py, Hp-7+Py and
 Hp-28+Py lumped together coinfected (Py first) = Py-14+Hp and Py-28+Hp
 lumped together Hp first = Hp-7+Py and Hp-28+Py lumped together Py first =
 Py-14+Hp and Py-28+Hp lumped together ### 2_data_on_spleen_mass
 (associated to 2_code_spleen_mass) replicate : the identity of the
 replicated dataset (1 or 2) time_post_infection : the time post infection
 in days (for coinfected groups this refers to time post second infection)
 log_spleen_mass : log10 transformed spleen mass (mg) Treatment :
 non-infected = control individuals single Hp = single infection with
 Heligmosomoides polygyrus single Py = single infection with Plasmodium
 yoelii Hp+Py = same day infection with the two parasites Hp-7+Py = first
 infection with Heligmosomoides polygyrus and after 7 days second infection
 with Plasmodium yoelii Hp-28+Py = first infection with Heligmosomoides
 polygyrus and after 28 days second infection with Plasmodium yoelii
 Py-14+Hp = first infection with Plasmodium yoelii and after 14 days second
 infection with Heligmosomoides polygyrus Py-28+Hp = first infection with
 Plasmodium yoelii and after 28 days second infection with Heligmosomoides
 polygyrus coinfected (simultaneous and Hp first) = Hp+Py, Hp-7+Py and
 Hp-28+Py lumped together coinfected (Py first) = Py-14+Hp and Py-28+Hp
 lumped together Hp first = Hp-7+Py and Hp-28+Py lumped together Py first =
 Py-14+Hp and Py-28+Hp lumped together ### 3_data_on_ast (associated to
 3_code_ast) replicate : the identity of the replicated dataset (1 or 2)
 time_post_infection : the time post infection in days (for coinfected
 groups this refers to time post second infection) ast : levels of
 aspartate aminotransferare in plasma (ng/ml) Treatment : non-infected =
 control individuals single Hp = single infection with Heligmosomoides
 polygyrus single Py = single infection with Plasmodium yoelii Hp+Py = same
 day infection with the two parasites Hp-7+Py = first infection with
 Heligmosomoides polygyrus and after 7 days second infection with
 Plasmodium yoelii Hp-28+Py = first infection with Heligmosomoides
 polygyrus and after 28 days second infection with Plasmodium yoelii
 Py-14+Hp = first infection with Plasmodium yoelii and after 14 days second
 infection with Heligmosomoides polygyrus Py-28+Hp = first infection with
 Plasmodium yoelii and after 28 days second infection with Heligmosomoides
 polygyrus coinfected (simultaneous and Hp first) = Hp+Py, Hp-7+Py and
 Hp-28+Py lumped together coinfected (Py first) = Py-14+Hp and Py-28+Hp
 lumped together Hp first = Hp-7+Py and Hp-28+Py lumped together Py first =
 Py-14+Hp and Py-28+Hp lumped together ### 4_data_on_survival (associated
 to 4_code_survival) replicate : the identity of the replicated dataset
 (from 1 to 4) time_to_event : the time post infection (post second
 infection in coinfected groups) in days when the event (reaching of the
 end point) was recorded censor : 0 = censored events, 1 = events Treatment
 : non-infected = control individuals single Hp = single infection with
 Heligmosomoides polygyrus single Py = single infection with Plasmodium
 yoelii Hp+Py = same day infection with the two parasites Hp-7+Py = first
 infection with Heligmosomoides polygyrus and after 7 days second infection
 with Plasmodium yoelii Hp-28+Py = first infection with Heligmosomoides
 polygyrus and after 28 days second infection with Plasmodium yoelii
 Py-14+Hp = first infection with Plasmodium yoelii and after 14 days second
 infection with Heligmosomoides polygyrus Py-28+Hp = first infection with
 Plasmodium yoelii and after 28 days second infection with Heligmosomoides
 polygyrus coinfected (simultaneous and Hp first) = Hp+Py, Hp-7+Py and
 Hp-28+Py lumped together coinfected (Py first) = Py-14+Hp and Py-28+Hp
 lumped together Hp first = Hp-7+Py and Hp-28+Py lumped together Py first =
 Py-14+Hp and Py-28+Hp lumped together ### 5_data_on_parasitemia
 (associated to 5_code_parasitemia) mouse_id : the identity of the mouse
 replicate : the identity of the replicated dataset (1 or 2)
 time_post_infection : the time post infection in days (for coinfected
 groups this refers to time post second infection) parasitemia : proportion
 of Plasmodium yoelii infected red blood cells number_rbc : number of reb
 blood cells number_irbc : number of infected red blood cells Treatment :
 single Py = single infection with Plasmodium yoelii Hp+Py = same day
 infection with the two parasites Hp-7+Py = first infection with
 Heligmosomoides polygyrus and after 7 days second infection with
 Plasmodium yoelii Hp-28+Py = first infection with Heligmosomoides
 polygyrus and after 28 days second infection with Plasmodium yoelii
 coinfected (simultaneous and Hp first) = Hp+Py, Hp-7+Py and Hp-28+Py
 lumped together ### 6_data_on_red_blood_cell_counts (associated to
 6_code_rbc) mouse_id : the identity of the mouse time_post_infection : the
 time post infection in days (for coinfected groups this refers to time
 post second infection) rbc : red blood cell counts (x 106/µl) Treatment:
 non-infected = control individuals single Hp = single infection with
 Heligmosomoides polygyrus single Py = single infection with Plasmodium
 yoelii Hp+Py = simultaneous infection with the two parasites Hp-7+Py =
 first infection with Heligmosomoides polygyrus and after 7 days second
 infection with Plasmodium yoelii Hp-28+Py = first infection with
 Heligmosomoides polygyrus and after 28 days second infection with
 Plasmodium yoelii coinfected (simultaneous and Hp first) = Hp+Py, Hp-7+Py
 and Hp-28+Py lumped together ### 7_data_on_epo_levels (associated to
 7_code_epo) replicate : the identity of the replicated dataset (1 or 2)
 time_post_infection : the time post infection in days (for coinfected
 groups this refers to time post second infection) log_epo : log
 transformed plasma levels of erythropoietin (ng/ml) Treatment :
 non-infected = control individuals single Py = single infection with
 Plasmodium yoelii Hp+Py = same day infection with the two parasites
 Hp-7+Py = first infection with Heligmosomoides polygyrus and after 7 days
 second infection with Plasmodium yoelii Hp-28+Py = first infection with
 Heligmosomoides polygyrus and after 28 days second infection with
 Plasmodium yoelii coinfected (simultaneous and Hp first) = Hp+Py, Hp-7+Py
 and Hp-28+Py lumped together ### 8_data_on_mean_globular_volume
 (associated to 8_code_mgv) mouse_id : the identity of the mouse
 time_post_infection : the time post infection in days (for coinfected
 groups this refers to time post second infection) mgv : mean globular
 volume (fL) Treatment : non-infected = control individuals single Hp =
 single infected with Heligmosomoides polygyrus single Py = single
 infection with Plasmodium yoelii Hp+Py = same day infection with the two
 parasites Hp-7+Py = first infection with Heligmosomoides polygyrus and
 after 7 days second infection with Plasmodium yoelii Hp-28+Py = first
 infection with Heligmosomoides polygyrus and after 28 days second
 infection with Plasmodium yoelii coinfected (simultaneous and Hp first) =
 Hp+Py, Hp-7+Py and Hp-28+Py lumped together ### 9_data_on_tolerance
 (associated to 9_code_tolerance) mouse_id : the identity of the mouse
 time_post_infection : the time post infection in days (for coinfected
 groups this refers to time post second infection) lrbc : red blood cell
 counts ((ln (x 106/µl)) lp : Plamsodium yoelii parasitemia ((ln
 (proportion infected red blood cells)) Treatment : single Py = single
 infection with Plasmodium yoelii coinfected (simultaneous and Hp first) =
 Hp+Py, Hp-7+Py and Hp-28+Py lumped together ###
 10_data_relative_to_the_epo_treatment (associated to
 10_code_epo_treatment_and_tolerance) mouse_id : the identity of the mouse
 time_post_infection : the time post Plasmodium yoelii infection in days
 body_mass : host body mass (g) rbc : red blood cell counts (x106/µl)
 time_to_event : the time post Plasmodium yoelii infection in days when the
 event (reaching of the end point) was recorded censor : 0 = censored
 events, 1 = events Treatment :PBS = control individuals EPO = rEPO treated
 individuals ### 11_data_on_tolerance_in_epo_treated_hosts (associated to
 10_code_epo_treatment_and_tolerance) mouse_id : the identity of the mouse
 time_post_infection : the time post infection in days (for coinfected
 groups this refers to time post second infection) lrbc : red blood cell
 counts ((ln (x 106/µl)) lp : Plasmodium yoelii parasitemia ((ln
 (proportion of infected red blood cells)) Treatment : single Py = single
 infection with Plasmodium yoelii coinfected + EPO = Hp-28+Py treated with
 EPO ### 12_data_on_hmox1_gene_expression_and_HO1 (associated to
 12_code_hmox1_gene_expression and 12_code_HO1) replicate : the identity of
 the replicated dataset (1 or 2) time_post_infection : the time post
 infection in days (for coinfected groups this refers to time post second
 infection) delta_ct_hmox1 : delta ct of hmox1 gene with respect to
 beta-actin foldchange : fold change of hmox1 gene with respect to the
 non-infected group log_HO1 : log transformed plasma levels of heme
 oxygenase 1 (ng/ml) Treatment : non-infected = control individuals single
 Py = single infection with Plasmodium yoelii Hp+Py = same day infection
 with the two parasites Hp-7+Py = first infection with Heligmosomoides
 polygyrus and after 7 days second infection with Plasmodium yoelii
 Hp-28+Py = first infection with Heligmosomoides polygyrus and after 28
 days second infection with Plasmodium yoelii coinfected (simultaneous and
 Hp first) = Hp+Py, Hp-7+Py and Hp-28+Py lumped together ###
 13_data_on_CD163 (associated to 13_code_cd163) replicate : the identity of
 the replicated dataset (1 or 2) time_post_infection : the time post
 infection in days (for coinfected groups this refers to time post second
 infection) cd163 : proportion of red pulp macrophages (F4/80+ CD11b-
 cells) that were cd163+ MFI : cd163 mean fluorescence intensity (arbitrary
 unit) Treatment : non-infected = control individuals single Py = single
 infection with Plasmodium yoelii Hp+Py = same day infection with the two
 parasites Hp-7+Py = first infection with Heligmosomoides polygyrus and
 after 7 days second infection with Plasmodium yoelii Hp-28+Py = first
 infection with Heligmosomoides polygyrus and after 28 days second
 infection with Plasmodium yoelii coinfected (simultaneous and Hp first) =
 Hp+Py, Hp-7+Py and Hp-28+Py lumped together ###
 14_data_on_ifn_gamma_gene_expression (associated to
 14_code_ifngamma_gene_expression) replicate : the identity of the
 replicated dataset (1 or 2) time_post_infection : the time post infection
 in days (for coinfected groups this refers to time post second infection)
 delta_ct_ifn : delta ct of IFN-gamma gene with respect to beta-actin
 foldchange : fold change of IFN-gamma gene with respect to the
 non-infected group Treatment : non-infected = control individuals single
 Py = single infection with Plasmodium yoelii Hp+Py = same day infection
 with the two parasites Hp-7+Py = first infection with Heligmosomoides
 polygyrus and after 7 days second infection with Plasmodium yoelii
 Hp-28+Py = first infection with Heligmosomoides polygyrus and after 28
 days second infection with Plasmodium yoelii coinfected (simultaneous and
 Hp first) = Hp+Py, Hp-7+Py and Hp-28+Py lumped together ###
 15_data_on_il10_gene_expression (associated to
 15_code_il10_gene_expression) replicate : the identity of the replicated
 dataset (1 or 2) time_post_infection : the time post infection in days
 (for coinfected groups this refers to time post second infection)
 delta_ct_il10 : delta ct of IL-10 gene with respect to beta-actin
 foldchange : fold change of IL-10 gene with respect to the non-infected
 group Treatment : non-infected = control individuals single Py = single
 infection with Plasmodium yoelii Hp+Py = same day infection with the two
 parasites Hp-7+Py = first infection with Heligmosomoides polygyrus and
 after 7 days second infection with Plasmodium yoelii Hp-28+Py = first
 infection with Heligmosomoides polygyrus and after 28 days second
 infection with Plasmodium yoelii coinfected (simultaneous and Hp first) =
 Hp+Py, Hp-7+Py and Hp-28+Py lumped together ###
 16_data_on_tgf_beta1_gene_expression (associated to
 16_code_tgfbeta1_gene_expression) replicate : the identity of the
 replicated dataset (1 or 2) time_post_infection : the time post infection
 in days (for coinfected groups this refers to time post second infection)
 delta_ct_tgf : delta ct of tgf-beta1 gene with respect to beta-actin
 foldchange : fold change of tgf-beta1 gene with respect to the
 non-infected group Treatment : non-infected = control individuals single
 Py = single infection with Plasmodium yoelii Hp+Py = same day infection
 with the two parasites Hp-7+Py = first infection with Heligmosomoides
 polygyrus and after 7 days second infection with Plasmodium yoelii
 Hp-28+Py = first infection with Heligmosomoides polygyrus and after 28
 days second infection with Plasmodium yoelii coinfected (simultaneous and
 Hp first) = Hp+Py, Hp-7+Py and Hp-28+Py lumped together ###
 17_data_on_the_proportion_of_treg_cells_and_ctla4_positive_treg
 (associated to 17_code_treg_and_ctla4_treg) replicate: the identity of the
 replicated dataset (1 or 2) time_post_infection : the time post infection
 in days (for coinfected groups this refers to time post second infection)
 treg : proportion of FoxP3+ among CD4+ t cells ctla4 : proportion of
 CTLA-4+ among FoxP3+ CD4+ t cells Treatment : non-infected = control
 individuals single Py = single infection with Plasmodium yoelii Hp+Py =
 same day infection with the two parasites Hp-7+Py = first infection with
 Heligmosomoides polygyrus and after 7 days second infection with
 Plasmodium yoelii Hp-28+Py = first infection with Heligmosomoides
 polygyrus and after 28 days second infection with Plasmodium yoelii
 coinfected (simultaneous and Hp first) = Hp+Py, Hp-7+Py and Hp-28+Py
 lumped together ### 18_data_on_the_immune_cell_populations_and_the_PCA
 (associated to 18_code_pca_on_immune_cells) replicate : the identity of
 the replicated dataset (1 or 2) time_post_infection : the time post
 infection in days (for coinfected groups this refers to time post second
 infection) Th1 : proportion of Tbet+ among CD4+ t cells Th17 : proportion
 of rorgt+ among CD4+ t cells Th2 : proportion of gata3+ among CD4+ t cells
 Tcells : proportion of CD3+ among CD45+ cells Bcells : proportion of CD19+
 among CD45+ cells Neutrophil : proportion of ly6g+ among CD45+ cells
 Macrophage : proportion of f4/80+ CD11b+ among CD3- CD19- cells DC :
 proportion of cmhii high CD11c high among CD3- CD19- cells RPM :
 proportion of f4/80+ CD11b- among CD3- CD19- cells monocytes : proportion
 of f4/80-/low CD11b+ among CD3- CD19- cells CD4 : proportion of CD4+ among
 CD3+ cells CD8 : proportion of CD8+ among CD3+ cells Treg : proportion of
 foxp3+ among CD4+ cells MemoryB : proportion of tbet+ among CD19+ cells
 ImmatureB : proportion of CD127+ among CD19+ cells CD163p : proportion of
 CD163+ among f4/80+ CD11b- cells CD163n : proportion of CD163- among
 f4/80+ CD11b- cells Ly6Chigh : proportion of ly6c high among f4/80-/low
 CD11b+ cells Ly6Clow : proportion of ly6c -/low among f4/80-/low CD11b+
 cells Ly6Cint : proportion of ly6c int among f4/80-/low CD11b+ cells Prin1
 : values of the first principal component from a PCA on the 20 immune cell
 populations Prin2 : values of the second principal component from a PCA on
 the 20 immune cell populations Treatment : non-infected = control
 individuals single Py = single infection with Plasmodium yoelii coinfected
 (simultaneous and Hp first) = Hp+Py, Hp-7+Py and Hp-28+Py lumped together
 ### 19_data_on_the_proportion_of_th2_and_cd8_cells (associated to
 19_code_th2 and 19_code_cd8) replicate : the identity of the replicated
 dataset (1 or 2) time_post_infection : the time post infection in days
 (for coinfected groups this refers to time post second infection) Th2 :
 proportion of gata3+ among CD4+ t cells CD8 : proportion of CD8+ among
 CD3+ cells Treatment : non-infected = control individuals single Py =
 single infection with Plasmodium yoelii coinfected (simultaneous and Hp
 first) = Hp+Py, Hp-7+Py and Hp-28+Py lumped together ###
 20_data_on_immune_checkpoints_in_cd8 (associated to
 20_code_cd8_immune_checkpoints) replicate : the identity of the replicated
 dataset (1 or 2) time_post_infection : the time post infection in days
 (for coinfected groups this refers to time post second infection) ctla4 :
 proportion of CD8+ t cells that were CTLA4+ pd1 : proportion of CD8+ t
 cells that were PD1+ lag3 : proportion of CD8+ t cells that were LAG3+
 Treatment : non-infected = control individuals single Py = single
 infection with Plasmodium yoelii Hp+Py = same day infection with the two
 parasites Hp-7+Py = first infection with Heligmosomoides polygyrus and
 after 7 days second infection with Plasmodium yoelii Hp-28+Py = first
 infection with Heligmosomoides polygyrus and after 28 days second
 infection with Plasmodium yoelii coinfected (simultaneous and Hp first) =
 Hp+Py, Hp-7+Py and Hp-28+Py lumped together ###
 21_data_on_the_correlation_between_survival_and_cd4cd8_ratio (associated
 to 21_code_cd4cd8_vs_mortality_rate) time_post_infection : the time post
 infection in days (for coinfected groups this refers to time post second
 infection) CD4CD8 : ratio between the proportion of CD4+ among CD3+ cells
 and the proportion of CD8+ among CD3+ cells mortality : proportion of
 individuals having reached the end points per treatment Treatment :
 non-infected = control individuals single Py = single infection with
 Plasmodium yoelii Hp+Py = same day infection with the two parasites
 Hp-7+Py = first infection with Heligmosomoides polygyrus and after 7 days
 second infection with Plasmodium yoelii Hp-28+Py = first infection with
 Heligmosomoides polygyrus and after 28 days second infection with
 Plasmodium yoelii ## Code/Software Data files are .xlsx that can be read
 with excel. Code files are .txt that can be read with SAS Studio (the
 software used to analyse the data and draw the figures).