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W pracy przedstawiono nowe dane wskazujące na skład mikrobiomu przewodu pokarmowego człowieka, składający się z bakterii, archeonów, wirusów (w tym bakteriofagów), a także organizmów eukariotycznych i heterotroficznych jakimi są grzyby – których bytowanie w przewodzie pokarmowym określane jest mianem mykobiomu. Przewód pokarmowy człowieka podzielony na jamę ustną, gardło, przełyk, żołądek, jelito cienkie i grube, zasiedlany wyżej wymienionymi drobnoustrojami, tworzy swoisty jakościowo-ilościowy, bogaty i zróżnicowany swoisty ekosystem. Dzięki stosowaniu metod bioinformatycznych, molekularnych oraz dzięki sekwencjonowaniu metagenomowemu jest on nadal poznawany, a dzięki tym metodom możliwe jest jego lepsze poznanie. W niniejszej pracy scharakteryzowano grupy systematyczne bakterii, archeonów, wirusów i grzybów występujące w poszczególnych odcinkach przewodu pokarmowego i wskazano także na enterotypy jelita grubego. Analizując wymienione grupy mikroorganizmów w poszczególnych odcinkach przewodu pokarmowego człowieka, należy zauważyć, że odcinek jelita grubego i jamy ustnej jest „wyposażony” w najbardziej bogaty mikrobiom, natomiast gardło i przełyk posiada najmniejszą liczbę drobnoustrojów wchodzących w skład mikrobiomu. Wśród całości mikrobiomu przewodu pokarmowego człowieka najliczniejszą grupę stanowią bakterie usytuowane w jamie ustnej i jelicie cienkim, zaś najbardziej ograniczoną grupę bakterii rejestruje się w gardle i przełyku. Archeony natomiast zostały opisane najliczniej w jelicie grubym i jamie ustnej, a nie zostały stwierdzone w gardle i jelicie cienkim. Wymieniane w odcinkach przewodu pokarmowego wirusy, najliczniej występowały w jelicie grubym i jamie ustnej, natomiast nie stwierdzono ich w żołądku. Występujące w mikrobiomie grzyby, najobficiej stwierdzane były w jelicie grubym i żołądku, a w najmniejszej ilości w gardle i jelicie cienkim.

The article characterises platelets, pointing out the role and contribution of their numerous receptors determining their specific and broad immune activity. Three types of platelet receptors are described, that is, extracellular and intracellular receptors—TLR (toll-like receptors), NLR (NOD-like receptor), and RLR (RIG-I-like receptor); extracellular receptors—selectins and integrins; and their other extracellular receptors—CLR (C-type lectin receptor), CD (cluster of differentiation), TNF (tumour necrosis factor), among others. Outlining the contribution of these numerous platelet receptors to the intravascular immunity, it has been shown that they are formed by their fusion with pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs), and lifestyle-associated molecular patterns (LAMPs). They are initiating and effector components of signal transduction of these cells, and their expression and quantity determine the specific and broad functions of platelets towards influencing vascular endothelial cells, but mainly PRRs (pattern recognition receptors) of blood immune cells. These facts make platelets the fundamental elements that shape not only intravascular homeostasis, as previously indicated, but they become the determinants of immunity in blood vessels. Describing the reactions of the characterised three groups of platelet receptors with PAMP, DAMP and LAMP molecules, the pathways and participation of platelets in the formation and construction of intravascular immune status, in physiological states, but mainly in pathological states, including bacterial and viral infections, are presented, making these cells essential elements in the health and disease of mammals, including humans. [ABSTRACT FROM AUTHOR]

Based on analysis of available genome sequences, five gene lineages of MHC class I molecules (MHC I-U, -Z, -S, -L and -P) and one gene lineage of MHC class II molecules (MHC II-D) have been identified in Osteichthyes. In the latter lineage, three MHC II molecule sublineages have been identified (MHC II-A, -B and -E). As regards MHC class I molecules in Osteichthyes, it is important to take note of the fact that the lineages U and Z in MHC I genes have been identified in almost all fish species examined so far. Phylogenetic studies into MHC II molecule genes of sublineages A and B suggest that they may be descended from the genes of the sublineage named A/B that have been identified in spotted gar (Lepisosteus oculatus). The sublineage E genes of MHC II molecules, which represent the group of non-polymorphic genes with poor expression in the tissues connected with the immune system, are present in primitive fish, i.e. in paddlefish, sturgeons and spotted gar (Lepisosteus oculatus), as well as in cyprinids (Cyprinidae), Atlantic salmon (Salmo salar), and rainbow trout (Oncorhynchus mykiss). Full elucidation of the details relating to the organisation and functioning of the particular components of the major histocompatibility complex in Osteichthyes can advance the understanding of the evolution of the MHC molecule genes and the immune mechanism.

Thrombocytes in vertebrates other than mammals, inter alia in fish, are analogues of platelets in mammals. In Osteichthyes, these cells take part in haemostatic processes, including aggregation and release reactions in cases of blood vessel damage, and in the immune response development as well. This paper discusses the development of thrombocytes in Osteichthyes, taking into account the need to make changes to the concept of grouping progenitor cells as suggested in the literature. The following pages present the morphological and cytochemical properties of thrombocytes as well as their defence functions, and also point out differences between thrombocytes in fish and platelets in mammals. The paper further highlights the level of thrombocytes’ immune activity observed in fish and based on an increased proportion of these cells in response to antigenic stimulation, on morphological shifts towards forms characteristic of dendritic cells after antigenic stimulation and on the presence of surface structures and cytokines released through, inter alia, gene expression of TLR receptors, MHC class II protein-coding genes and pro-inflammatory cytokines. The study also points out the need to recognise thrombocytes in Osteichthyes as specialised immune cells conditioning non-specific immune mechanisms and playing an important role in affecting adaptive immune mechanisms.

Cathelicidins are Important immunological peptides – HDPs (Host Defense Peptides) with high biological activity in mammals, including human and vertebrate animals. These evolutionary ancient molecules in these organisms are natural elements of antimicrobial, antiviral, antifungal and antiparasitic immunity against which germs and parasites have not developed immunity, which makes them alternatives to antibiotics. Catelicidins in human and vertebrates affect the germs and parasites directly and indirectly by activating the immune system.

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Defensins are immune peptides - HDP (Host Defense Peptides) that present high activity against viruses, bacteria and fungi in mammals, including humans. They are an important element of natural resistance in macroorganisms, when microorganisms couldn't developed this resistance during the evolution. Defensins in vertebrate macroorganisms, have direct and indirect impact on germs, including stimulating the synthesis of immune substances such as cytokines, chemokines and growth factors. [ABSTRACT FROM AUTHOR]

Copyright of Advancements of Microbiology is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)