PhD Scientific Days 2022

Molecular Sciences I. (Poster discussion will take place in the Aula during the Coffee Break)

Characterization and Development of the Lymphoid Follicular Cortex of the Bursa of Fabricius

Előadó neve

Soós, Ádám, MSc

Előadó munkahelye

Department of Anatomy-, Histology and Embryology

Előadó telefonszáma

+36709445069

Előadó e-mail címe

soos.adam10@gmail.com

Az előadás címe

Characterization and Development of the Lymphoid Follicular Cortex of the Bursa of Fabricius

Szerző(k) neve és munkahelye

Ádám Soós1, Emőke Szőcs1, Nóra Fejszák1, Dalma Jancsovics1,
Viktória Halasy1, Tamás Kovács1, Nándor Nagy1

1 Semmelweis University, Department of Anatomy-, Histology and Embryology, Budapest

Bemutatás módja

Poszter

Szekció

Molecular Sciences I. (Poster discussion will take place in the Aula during the Coffee Break)

Language of the presentation

English

Preferred session

Molecular Sciences

Összefoglaló szövege

Introduction
The bursa of Fabricius (BF) is a primary lymphoid organ, unique in birds, that is responsible for the development of B cells within its follicular microenvironment. The bursal lymphoid follicles consist of two histologically and embryological distinct compartments: the ectodermal medulla and the cortex of mesodermal origin.
Aims
Despite the fact that the histology of the follicular medulla is well characterized, the morphology of the ontogenetically later emerging cortex is less clear.
Our aims are:
• Histological characterization of the follicular cortex with the help of immunohistochemistry and electronmicroscopy
• Detailed characterization of the cortical extracellular matrix proteins
• Ontogeny of the follicular cortex
Methods
Embedding, immunohistochemistry, embryomanipulation techniques, chorioallantoic membrane transplantation, in vitro cell cultures, RCAS-shh virus usage, confocal/STED/electronmicroscopy and statistical analysis were used in these experiments.
Results
In this study, we describe the molecular composition and ontogeny of the BF follicular cortex. In contrast to medulla, the adult cortical CD45+/chB6+
B-lymphocytes express surface CXCR4. In the cortex the reticular cells produce extracellular matrix (ECM) rich in proteoglycans, collagens, and glycoproteins, unlike the medulla where there is no detectable ECM. Characterization of the ECM showed that compared to most of the ECM proteins, expression of Tenascin-C can be first observed on 16th day of embryogenesis surrounding the developing follicle buds. Tenascin-C blocked B-cell migration in the explant cultures of embryonic BF. Similarly, RCAS-Shh retroviral vector-induced overexpression of Tenascin-C inhibits B-cell colonization of developing follicles.
Conclusion
1) development of the follicle cortex starts before hatching; 2) the B-cells of the cortical follicle shows a specific Bu-1+/CXCR4+/IgM low expression pattern, and has a CSF1R+/TIM4+/Lep100+ macrophage population; 3) the scaffold of the cortex is composed of mesenchymal reticulum cells that produce ECM; 4) In vivo and in vitro experiments show that Tenascin-C provides an inhibitory environment for B-cell migration.
Funding
Grant: NKFI - 138664

University and Doctoral School

Semmelweis University, Doctoral School of Molecular Medicine

Supervisor

Dr. Nándor Nagy

Publication of my abstract

I give consent to the publication of my abstract on the website of the congress.

Kind

Szabad

Status

elfogadva

Accepted presentation method

poszter

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

6829

Start

11:00

End

11:05

Authors (legacy)

Ádám Soós1, Emőke Szőcs1, Nóra Fejszák1, Dalma Jancsovics1,
Viktória Halasy1, Tamás Kovács1, Nándor Nagy1

1 Semmelweis University, Department of Anatomy-, Histology and Embryology, Budapest