Modulation of the skin microbiome in cutaneous T-cell lymphoma delays tumour growth and increases survival in the murine EL4 model.

Cutaneous T-cell lymphomas (CTCL) are a group of lymphoproliferative disorders of skin-homing T cells causing chronic inflammation. These disorders cause impairment of the immune environment, which leads to severe infections and/or sepsis due to dysbiosis. In this study, we elucidated the host-microbial interaction in CTCL that occurs during the phototherapeutic treatment regime and determined whether modulation of the skin microbiota could beneficially affect the course of CTCL. EL4 T-cell lymphoma cells were intradermally grafted on the back of C57BL/6 mice. Animals were treated with conventional therapeutics such as psoralen + UVA (PUVA) or UVB in the presence or absence of topical antibiotic treatment (neomycin, bacitracin, and polymyxin B sulphate) as an adjuvant. Microbial colonisation of the skin was assessed to correlate with disease severity and tumour growth. Triple antibiotic treatment significantly delayed tumour occurrence (p = 0.026), which prolonged the survival of the mice (p = 0.033). Allocation to phototherapeutic agents PUVA, UVB, or none of these, along with antibiotic intervention, reduced the tumour growth significantly (p = 0.0327, p ≤ 0.0001, p ≤ 0.0001 respectively). The beta diversity indices calculated using the Bray-Curtis model showed that the microbial population significantly differed after antibiotic treatment (p = 0.001). Upon modulating the skin microbiome by antibiotic treatment, we saw an increase in commensal Clostridium species, e.g., Lachnospiraceae sp. (p = 0.0008), Ruminococcaceae sp. (p = 0.0001)., Blautia sp. (p = 0.007) and a significant reduction in facultative pathogens Corynebacterium sp. (p = 0.0009), Pelomonas sp. (p = 0.0306), Streptococcus sp. (p ≥ 0.0001), Pseudomonas sp. (p = 0.0358), and Cutibacterium sp. (p = 0.0237). Intriguingly, we observed a significant decrease in Staphylococcus aureus frequency (p = 0.0001) but an increase in the overall detection frequency of the Staphylococcus genus, indicating that antibiotic treatment helped regain the microbial balance and increased the number of non-pathogenic Staphylococcus populations. These study findings show that modulating microbiota by topical antibiotic treatment helps to restore microbial balance by diminishing the numbers of pathogenic microbes, which, in turn, reduces chronic inflammation, delays tumour growth, and increases survival rates in our CTCL model. These findings support the rationale to modulate the microbial milieu during the disease course of CTCL and indicate its therapeutic potential.

An overview of solutions for airborne viral transmission reduction related to HVAC systems including liquid desiccant air-scrubbing.

The spread of the coronavirus SARS-CoV-2 affects the health of people and the economy worldwide. As air transmits the virus, heating, ventilation and air-conditioning (HVAC) systems in buildings, enclosed spaces and public transport play a significant role in limiting the transmission of airborne pathogens at the expenses of increased energy consumption and possibly reduced thermal comfort. On the other hand, liquid desiccant technology could be adopted as an air scrubber to increase indoor air quality and inactivate pathogens through temperature and humidity control, making them less favourable to the growth, proliferation and infectivity of microorganisms. The objectives of this study are to review the role of HVAC in airborne viral transmission, estimate its energy penalty associated with the adoption of HVAC for transmission reduction and understand the potential of liquid desiccant technology. Factors affecting the inactivation of pathogens by liquid desiccant solutions and possible modifications to increase their heat and mass transfer and sanitising characteristics are also described, followed by an economic evaluation. It is concluded that the liquid desiccant technology could be beneficial in buildings (requiring humidity control or moisture removal in particular when viruses are likely to present) or in high-footfall enclosed spaces (during virus outbreaks).

Determination of minimal persistent pigment dose of normal skin to long-wave ultraviolet among healthy volunteers / 中华医学美学美容杂志

Objective To investigate the minimal persistent pigment dose (MPPD)of normal skin to UVA in Guangzhou city,and to observe its relationship to sex,age,skin type,seasons,ITA,and the years lived in Guangzhou.Methods 316 healthy subjects were exposed to Solar 601-300,and the MPPD was measured and observed by two professional technicians after 2-3 hours.Results The average MPPD value of all subjects was (9.61±2.57) J/cm2.In male and female,the average MPPD values were (11.09 ± 2.82) J/cm2 and (9.01 ± 2.20) J/cm2 respectively,and male was significantly higher than female (P＜0.01).There was significant difference of the MPPD value in different seasons (P＜0.01).The MPPD value in winter (10.66± 2.71) J/cm2) was significantly higher than spring (9.37±2.39) J/cm2,summer (9.53±2.66) J/cm2 and autumn (8.98±2.25) J/cm2.There was significant difference of the MPPD value between different ITA groups (P＜0.01).ITA grade-3 (10.72± 2.84) J/cm2 was significantly higher than grade-1 (8.50±1.45) J/cm2 and grade-2 (9.12±2.31) J/cm2 (P＜0.01),but there was no significant difference from grade-4 (11.87±2.73) J/cm2 (P =0.93).The MPPD value in subjects lived in Guangzhou over 10 years (8.97± 1.88) J/cm2 was significantly lower than those whose residence was less than 1 year and from 1 to 5 years,respectively (P＜0.01),but there was no significant difference from those lived from 5 to 10 years (P =0.47).Conclusions The MPPD value of the subjects in Guangzhou is related to gender,seasons,ITA grade and the years lived in Guangzhou city,while there is no correlation with age and skin types.

Effect of selective cycloxygenase-2 inhibitor NS-398 on IL-10 and IFN-γ mRNA expression in hunman keratinocytes induced by long-wave ultraviolet / 中华医学美学美容杂志

Objective To study the effect of selective COX-2 inhibitor NS398 on IL-10 and IFN-γexpression in human keratinocytes induced by UVA,and further to explore the effect on anti human skin photoaging.Methods HaCaT cells were divided into three groups:simple UV exposure group,NS398-intervene group and blank group.For UV radiation,simple UV exposure group and NS398-intervene group were irradiated with UVA at a dose of 30 J/cm2.In order to assess the effect of NS398,HaCat cells were treated with NS398 at the dose of 0,20,40,80μmol/L respectively and then incubated without irradiation for 2h,substrate changed and cultured for 24h,and then the expression of IL-10 and IFN-γ mRNA was detected via RT-PCR.Results Simple UV exposure group had obviously higher expression of IL-10 mRNA and lower expression of IFN-γ mRNA than that of control group,while NS398-intervened group had significantly lower expression of IL-10 mRNA and higher expression of IFN-γ mRNA than that of simple UV exposure group,and dose-dependency existed.Conclusions NS398 may delay photo-damage of human skin via inhibiting the expression of IL-10 mRNA and up-regulating the expression of IFN-γ mRNA in human keractinocytes.