Anti-tumor necrosis factor α therapy associates to type 17 helper T lymphocytes immunological shift and significant microbial changes in dextran sodium sulphate colitis.

Abstract

BACKGROUND:

Anti-tumor necrosis factor α (TNFα) represents the best therapeutic option to induce mucosal healing and clinical remission in patients with moderate-severe ulcerative colitis. On the other side gut microbiota plays a crucial role in pathogenesis of ulcerative colitis but few information exists on how microbiota changes following anti-TNFα therapy and on microbiota role in mucosal healing.

AIM:

To elucidate whether gut microbiota and immune system changes appear following anti TNFα therapy during dextran sulfate sodium (DSS) colitis.

METHODS:

Eighty C57BL/6 mice were divided into four groups: "No DSS", "No DSS + anti-TNFα", "DSS" and "DSS + anti-TNFα". "DSS" and "DSS + anti-TNFα" were treated for 5 d with 3% DSS. At day 3, mice whithin "No DSS+anti-TNFα" and "DSS+anti-TNFα" group received 5 mg/kg of an anti-TNFα agent. Forty mice were sacrificed at day 5, forty at day 12, after one week of recovery post DSS. The severity of colitis was assessed by a clinical score (Disease Activity Index), colon length and histology. Bacteria such as Bacteroides, Clostridiaceae, Enterococcaceae and Fecalibacterium prausnitzii (F. prausnitzii) were evaluated by quantitative PCR. Type 1 helper T lymphocytes (Th1), type 17 helper T lymphocytes (Th17) and CD4+ regulatory T lymphocytes (Treg) distributions in the mesenteric lymph node (MLN) were studied by flow cytometry.

RESULTS:

Bacteria associated with a healthy state (i.e., such as Bacteroides, Clostridiaceae and F. prausnitzii) decreased during colitis and increased in course of anti-TNFα treatment. Conversely, microorganisms belonging to Enterococcaceae genera, which are linked to inflammatory processes, showed an opposite trend. Furthermore, in colitic mice treated with anti-TNFα microbial changes were associated with an initial increase (day 5 of the colitis) in Treg cells and a consequent decrease (day 12 post DSS) in Th1 and Th17 frequency cells. Healthy mice treated with anti-TNFα showed the same histological, microbial and immune features of untreated colitic mice. "No DSS + anti-TNFα" group showed a lymphomononuclear infiltrate both at 5th and 12th d at hematoxylin and eosin staining, an increase of in Th1 and Th17 frequency at day 12, an increase of Enterococcaceae at day 5, a decrease of Bacteroides and Clostridiaceae at day 12.

CONCLUSION:

Anti-TNFα treatment in experimental model of colitis improves disease activity but it is associated to an increase in Th17 pathway together with gut microbiota alteration.

• Authors: Valentina Petito, Cristina Graziani, Loris R Lopetuso, Marco Fossati, Alessandra Battaglia, Vincenzo Arena, Domenico Scannone, Gianluca Quaranta, Andrea Quagliariello, Federica Del Chierico, Lorenza Putignani, Luca Masucci, Maurizio Sanguinetti, Alessandro Sgambato, Antonio Gasbarrini, Franco Scaldaferri
• Journal: World journal of gastroenterology (World J Gastroenterol) Vol. 25 Issue 12 Pg. 1465-1477 (Mar 28 2019) ISSN: 2219-2840 [Electronic] United States
• PMID: 30948910 (Publication Type: Journal Article)

Chemical References

• Gastrointestinal Agents
• Tumor Necrosis Factor-alpha
• Dextran Sulfate
• Infliximab

Topics

• Animals
• Bacteria (drug effects, immunology, isolation & purification)
• Colitis, Ulcerative (chemically induced, diagnosis, drug therapy, immunology)
• Colon (drug effects, immunology, microbiology)
• Dextran Sulfate (toxicity)
• Disease Models, Animal
• Gastrointestinal Agents (adverse effects)
• Gastrointestinal Microbiome (drug effects, immunology)
• Humans
• Infliximab (adverse effects)
• Intestinal Mucosa (drug effects, immunology, microbiology)
• Mice
• Mice, Inbred C57BL
• Severity of Illness Index
• Th17 Cells (drug effects, immunology)
• Tumor Necrosis Factor-alpha (antagonists & inhibitors, immunology)