Role of neutrophils in immunosurveillance mechanisms at preneoplastic stages of carcinogenesis

What are the main cancers in number of cases for men and women?

• Men → prostate > lung > colon cancer

• Women → breast > colon > lung cancer

What are the main treatment nowadays?

• Surgery

• Chemotherapy

• Targeted therapy

• Hormonal therapy

• Radiation

• Immunotherapy

What are the goal of immunotherapy? What are the major issues?

Manipulate ans stimulate the immune system to break immune tolerance against tumor cells along with initiating specific memory T cells response.

Antitumor immunity resembles autoimmunity, since it requires the immune system to partially break self-tolerance to target cancer cells, which may lead to a too strong auto-immune response.

In what reside the future of immunotherapy? What are the main issues with immune checkpoints?

• Combination strategies

• Study of the microbiome

• CAR T cells

• Adoptive T cells therapy (ACT)

• Vaccines

Immune checkpoints→ the expression of certain molecules are not restricted to T cells, theres the risk of toxicity and resistance

Give a few examples of combination opportunities in cancer immunotherapy

• To activate immune response → chemotherapy, receptor inhibitors (EGFR, MEK…), radiotherapy…

• To recrute/infiltrate immune cells into the tumor → anti-VEGF (tumor blood vessels impair immune cell infiltration)

• Block immunosuppression → anti-PD1, anti-PDL1, anti-LAG3…

What’s present in the tumoral microenvironment?

CAFs, tumor cells, pericytes (regulating blood flow, metabolic fonction and possibly immune infiltration), blood vessels, lymphatic vessels and based on the tumor, an immune infiltrate

Can we have innate immune cells in the tumor microenvironment?

Yes, innate immune cells are present. It has been found that there’s an infiltration if neutrophils and plasmacytoid dendritic cells int the early malignant stages.

For each marker give the corresponding cell type: CD20, CD4, CD8, FoxP3, CD66b, CK, CD15

• CD20: B cells

• CD4: CD4 T cells

• CD8: CD8 T cells

• FoxP3: Treg cells

• CD66b: granulocytes

• CK (Cytokeratin): epithelial cells

• CD15: granulocytes

• CD11c: myeloid cells

What are the different tumorigenesis steps? At which stage we can innate immune cells infiltration?

• Hyperplasia and dysplasia (pre-neoplastic stages)

• Carcinoma in situ and adenocarcinoma (malignant stages)

• Metastasis

We can observe a neutrophil and plasmacytoid dendritic cells at the beginning of malignant stages (carcinoma in situ)

What are the 3E? In which patients we can already observe immunosuppression? And what are the consequences of immunosuppression?

Elimination, equilibrium and escape.

In transplanted patients along with AIDS patients that will have a higher change to develop cancer.

How many neutrophils we find in total blood leucocytes? And in granulocytes? How long is their lifetime? Can it be modulated? Are they one of the first effectors to be recruited? How neutrophiles can induce the destruction on pathogens?

They represent 60% of total blood leucocytes and 99% of granulocytes in human. They have a relatively short lifespan (10-12 hours) that can be modulates upon stimuli.

They are rapidly recruited in inflammatory ans infectious context.

Recognize pathogens via ADCC (presence of Fc receptor for IgG and IgA) and killing using ≠ mechanisms:

• Degranulation → secretion of anti-microbial molecules and cytokines

• Phagocytosis & Pinocytosis → ingestion of solid particles or extracellular fluids

• NETs (Neutrophil Extracellular Traps) release → chromatin & anti-microbial peptides

Which neutrophils family has anti-tumor properties? And which one had pro-tumor properties? Which molecules induce the ≠ of each family of neutrophils

• N1: anti-tumor properties by activating the immune ecosystem (helping with the proliferation of cytotoxic T cells, activating macrophages to produce INF-γ, APC-like).

• N2: genotoxicity (ROS, toxic molecules and NETosis causing chronic inflammation and inducing mutations in tumor cells which helps with proliferation), inducing inflammation and tumor-promoting tissue responses (angiogenesis, hypoxia…), inhibiting cytotoxic immune response (LT and NK cells). All this mechanisms leads to metastasis?

N1 are induced by INF-γ and INF-β and in the other hand N2 are induced by TGF-β and IL-10

Which is the main challenge when it comes to neutrophils in cancer?

Their heterogeneity in cancer, we deal with a very diverse panel, with many cellular states with broad functionalities, but only in late stage cancer.

It also will depend on the organ we are working on, its has been shown that the neutrophils circulating in the blood of cancer patients dont have the same transcriptomic and phenotype of the ones found in the cancer site.