Journal: bioRxiv

Article Title: Species and strain diversity in Staphylococcus drive divergent host responses in human skin

doi: 10.64898/2026.04.30.720712

Figure Lengend Snippet: (A) Biofilm formation ability of commensal vs. inflammatory S. epidermidis strains. Biofilm positive strains were defined relative to a canonical biofilm-forming strain (Sep_1457). Numbers indicate strain counts per category and P-value and odds ratio calculated using Fisher’s exact test. (B-E) Survival ability in blood as measured by CFUs at 0, 2, and 24h of S. epidermidis strains (D) with respect to a bloodstream infection S. aureus strain (USA300LAC, (B)) with or without complement (+/-Comp) depletion (C, E). Points represent individual strains (or replicates for S. aureus) and boxes indicate IQR with median. Lines connect matched conditions. Significance was assessed by paired t-test with Bonferroni correction. (F-G) PCA plot of Staphylococcus cellular (F) or extracellular (G) metabolomes. Staphylococcus metabolomes were inferred by metabolic feature intensity within untargeted metabolomes. (H) Diagram of arginine metabolism pathway highlighting reactions catalyzed by arcA , argF , and argG . (I-K) Violin plots showing the metabolite abundance of arginine (I), carbamoyl-P (J), and argininosuccinate (K) in strains with or without arcA , argF , or argG. Points indicate normalized metabolite intensity; violins show distributions with embedded boxplots (median and IQR). Gene labels are black if acting on or downstream of the metabolite, grey otherwise. (L-N) Growth dynamics of inflammatory vs. commensal S. epidermidis strains in skin-like media with (+Arg) or without (-Arg) arginine. Maximum growth rate (L), maximum density (M), and area under the curve (AUC) (N) are derived from OD600 measurements every 0.5h over 10 hours at 37C. Points represent strains with paired conditions connected with lines. Statistical significance was determined by paired t -test followed by Bonferroni correction. (O-Q) Protein expression of cytokines IL-8 (O), CCL20 (P) and IL-36γ (Q) in the basal media of Staphylococcus -colonized RHE was measured by ELISA (n=3-4 replicates per strain in an independent experiment colonizing 3 inflammatory and 4 commensal S. epidermidis strains and S. aureus as a reference). Points represent individual replicates colored by cluster and boxes show IQR with median. (R) Model summarizing species- and strain-level effects of Staphylococcus on RHE. Species-level differences distinguish commensal and pathogenic effects, while strain-level variation within S. epidermidis identifies inflammatory strains that activate a proinflammatory transcriptional program including upstream regulators (e.g. NFKB), chemokines (e.g., CCL20), cytokines (e.g., IL36γ) and downstream antimicrobial effectors (e.g. LCN2). Inflammatory S. epidermidis also enhances skin barrier defensive genes, particularly members of the LCE and SPRR gene families, which contribute to both barrier integrity and antimicrobial defense, and are regulated by transcription factors such as MAFB. These effects are linked to differences in gene content (e.g., cell surface genes), transcriptional programs, metabolism (e.g., arginine pathway), and pathogen-like growth phenotypes. P-values: **** p ≤ 0.0001, *** 0.0001 < p ≤ 0.001, ** 0.001 < p ≤ 0.01, * 0.01 < p ≤ 0.05., ns p > 0.05.

Article Snippet: Rabbit red blood cells with complement (Innovative Research Inc.; #IRBRBC10ML) was aliquoted into 96-well plates (150 μL per well).

Techniques: Infection, Derivative Assay, Expressing, Enzyme-linked Immunosorbent Assay

Journal: ImmunoHorizons

Article Title: Altered natural killer cell function in children with severe malaria

doi: 10.1093/immhor/vlaf070

Figure Lengend Snippet: Children with severe malaria (SM) had increased proportion of NK cell inhibitory receptor LILRB1 than community children (CC), but no differences in absolute counts of NK cells. (A) Flow cytometry staining of NK cell subsets defined by Living (Live dead marker and Annexin V − ), CD64 − , CD3 − , CD7 + showing CD56 and CD16 expression post–ADCC assay. Three major NK cell populations were identified: CD56 bright , CD56 dim , and CD56 neg after stimulation of PBMCs with uRBCs incubated in anti-human RBC antibody. (B) Absolute counts of total NK cells. (C–E) Absolute counts of NK cell subsets: CD56 dim (C), CD56 neg (D), and CD56 bright (E) between SM and CC. (F–H) Analysis of the proportion of LILRB1 in NK subsets: CD56 dim (F), CD56 neg (G), and CD56 bright (H). Each data point represents one participant with the red line indicating the median. Statistical significance was determined using Mann–Whitney U -test analysis between groups: SM ( n = 21) vs. CC ( n = 18) (one CC was missing the complete blood count), denoted by * P < .05.

Article Snippet: The uRBC suspension was incubated with rabbit anti-human RBC antibodies (Rockland) for 20 minutes at RT.

Techniques: Flow Cytometry, Staining, Marker, Expressing, ADCC Assay, Incubation, MANN-WHITNEY

Journal: ImmunoHorizons

Article Title: Altered natural killer cell function in children with severe malaria

doi: 10.1093/immhor/vlaf070

Figure Lengend Snippet: Increased proportion of degranulating NKG2C + , CD57 + , LILRB1 + , and LAG3 + NK cells in severe malaria (SM) compared to community children (CC). Flow cytometric analysis to evaluate the functional subsets of NK cells after stimulation with uRBCs incubated with anti-human RBC antibody, categorized based on NKG2C and CD57 expression between SM and CC. (A) Proportion of CD107a + NK cells among NKG2C + and NKG2C − in the CD56 dim NK subset. (B) Proportion of CD107a + NK cells among NKG2C + and NKG2C − in the CD56 neg NK subset. (C) Proportion of IFN-γ–producing NK cells among NKG2C + and NKG2C − in the CD56 dim NK subset. (D) Proportion of IFN-γ–producing NK cells among NKG2C + and NKG2C − in the CD56 neg NK subset. (E) Proportion of CD107a + NK cells based on NKG2C and CD57 markers in CD56 dim NK cells between SM and CC. (F) Proportion of CD107a + NK cells based on NKG2C and CD57 markers in CD56 neg NK cells between SM and CC. (G) Proportion of CD107a + NK cells in LILRB1 + and LILRB1 − populations in CD56 dim NK cells. (H) Proportion of CD107a + NK cells in LAG3 + and LAG3 − populations in CD56 dim NK cells. Each data point represents one participant with the red line indicating the median. Statistical significance between SM and CC was determined using Mann–Whitney U -test analysis between the SM ( n = 21) and CC ( n = 19) groups, denoted by * P < .05, ** P < .01, *** P < .001.

Article Snippet: The uRBC suspension was incubated with rabbit anti-human RBC antibodies (Rockland) for 20 minutes at RT.

Techniques: Functional Assay, Incubation, Expressing, MANN-WHITNEY

Journal: ImmunoHorizons

Article Title: Altered natural killer cell function in children with severe malaria

doi: 10.1093/immhor/vlaf070

Figure Lengend Snippet: NK cell function in children with severe malaria (SM) differs in areas of low vs. moderate malaria transmission. (A–E) Analysis of NK cell populations for SM and CC in low and moderate malaria transmission sites, when PBMCs were stimulated with uRBCs incubated with anti-RBC antibody. (A–C) Percentage of total NK cells (A), CD107a + CD56 dim NK cells (B), and CD107a + CD56 neg NK cells (C) were measured in the low and moderate malaria transmission sites. (D, E) Functional analysis of NK cell subsets, focusing on IFN-γ production. The percentage of IFN-γ + CD56 dim NK cells (D) and IFN-γ + CD56 neg NK cells (E) was evaluated under low and moderate malaria transmission sites. (F, G) Analysis of percentage of CD107a in NK cell phenotypic markers for SM (CD16, CD57, NKG2C, LAG3, LILRB1, SIGLEC7, and FcRγ) in CD56 dim (F) and CD56 neg (G) between low and moderate malaria transmission sites. (H, I) Analysis of percentage of IFN-γ in NK cell phenotypic markers for SM (CD16, CD57, NKG2C, LAG3, LILRB1, SIGLEC7, and FcRγ) in CD56 dim (H) and CD56 neg (I) between low and moderate malaria transmission sites. Each data point represents one participant with the red line indicating the median. Statistical significance between SM and CC in both low and moderate transmission sites (A–E) was determined using pairwise Dunn tests following Kruskal–Wallis tests. Statistical significance within SM between low and moderate transmission sites (F–I) was determined using Mann–Whitney U -test analysis. Significance denoted by * P < .05, ** P < .01, *** P < .001.

Article Snippet: The uRBC suspension was incubated with rabbit anti-human RBC antibodies (Rockland) for 20 minutes at RT.

Techniques: Cell Function Assay, Transmission Assay, Incubation, Functional Assay, MANN-WHITNEY

Journal: ImmunoHorizons

Article Title: Altered natural killer cell function in children with severe malaria

doi: 10.1093/immhor/vlaf070

Figure Lengend Snippet: Increased NK cell degranulation in children with severe malaria (SM) compared to community children (CC) is present in low but not moderate malaria transmission areas. In the same generic ADCC assay against RBCs, we separated the individuals by malaria transmission level being low (left) and moderate (right). (A) CD56 dim and (B) CD56 neg NK cells for the dual marker Boolean gating of NKG2C and CD57 assessing degranulation (CD107a) after an RBC ADCC assay with an anti-RBC antibody. Each data point represents one participant with the red line indicating the median. Statistical significance between SM and CC was determined using Mann–Whitney U -test analysis between the SM and CC groups, denoted by * P < .05, ** P < .01, *** P < .001.

Article Snippet: The uRBC suspension was incubated with rabbit anti-human RBC antibodies (Rockland) for 20 minutes at RT.

Techniques: Transmission Assay, ADCC Assay, Marker, MANN-WHITNEY

Journal: ImmunoHorizons

Article Title: Altered natural killer cell function in children with severe malaria

doi: 10.1093/immhor/vlaf070

Figure Lengend Snippet: The proportion of CD107a + IFN-γ − NK cell subsets is increased in children with severe malaria (SM) compared to community children (CC) only in an area of low malaria transmission, whereas the proportion of CD107a − IFN-γ + NK cell subsets is decreased in children with SM compared to CC in low and moderate transmission areas. Data assessing CD107a (degranulation) and IFN-γ (cytokine production) when PBMCs were stimulated with uRBCs incubated with anti-RBC antibody. CD56 dim NK cells were categorized into 3 populations: CD107a + IFN-γ − , CD107a + IFN-γ + , and CD107a − IFN-γ + . (A–H) For low (left) and moderate (right) malaria transmission, percentage of CD107a + IFN-γ − , CD107a + IFN-γ + , and CD107a − IFN-γ + cells in NK cell markers: (A) NKG2C, (B) CD57, (C) LILRB1, (D) FcRγ, (E) LAG3, and (F) SIGLEC7 negative within the CD56 dim NK cell between SM and CC. Each data point represents one participant with the red line indicating the median. Statistical significance between SM and CC was determined using Mann–Whitney U -test analysis between the SM ( n = 21) and CC ( n = 19) groups, denoted by * P < .05, ** P < .01, *** P < .001.

Article Snippet: The uRBC suspension was incubated with rabbit anti-human RBC antibodies (Rockland) for 20 minutes at RT.

Techniques: Transmission Assay, Incubation, MANN-WHITNEY