Antigens and Antibodies as Cell Phenotypes

Single-Cell Transcriptional Profiling of Cells Derived From Regenerating Alveolar Ducts

Lung regeneration occurs in a variety of adult mammals after surgical removal of one lung (pneumonectomy). Previous studies of murine post-pneumonectomy lung growth have identified regenerative “hotspots” in subpleural alveolar ducts; however, the cell-types participating in this process remain unclear. To identify the single cells participating in post-pneumonectomy lung growth, we used laser microdissection, enzymatic digestion and microfluidic isolation. Single-cell transcriptional analysis of the murine alveolar duct cells was performed using the C1 integrated fluidic circuit (Fluidigm) and a custom PCR panel designed for lung growth and repair genes. The multi-dimensional data set was analyzed using visualization software based on the tSNE algorithm. The analysis identified 6 cell clusters; 1 cell cluster was present only after pneumonectomy. This post-pneumonectomy cluster was significantly less transcriptionally active than 3 other clusters and may represent a transitional cell population. A provisional cluster identity for 4 of the 6 cell clusters was obtained by embedding bulk transcriptional data into the tSNE analysis. The transcriptional pattern of the 6 clusters was further analyzed for genes associated with lung repair, matrix production, and angiogenesis. The data demonstrated that multiple cell-types (clusters) transcribed genes linked to these basic functions. We conclude that the coordinated gene expression across multiple cell clusters is likely a response to a shared regenerative microenvironment within the subpleural alveolar ducts.

Die Bedeutung der Plasmazellen als Antikörperbildner

During the last two decades, it has been shown by a great number of morphological, clinical, and experimental investigations that the humoral antibodies are formed by plasma cells. Plasma cells are immobile connective tissue cells which are formed in the medullary cords of lymph nodes, the red pulp of the spleen, the bone marrow, and in the adventitia of small blood vessels.

The theory of the plasmacellular antibody formation is based on these clinical and experimental observations: (1) Correlation of hypergammaglobulinemia in the blood serum and proliferation of plasma cells in the tissue in various diseases of men and animals. (2) Correlation of antibody concentration in the blood serum and plasma cell proliferation in hyperimmunized experimental animals. (3) Demonstration of antibody formation in plasma cells by in vitro experiments and extraction of γ-globulin from plasma cells. (4) Detection of antibodies in plasma cells with the fluorescent antibody technique.

Macrophages and lymphocytos also play a role in antibody formation. While it is the function of the macrophages to transform corpuscular antigen into soluble immunogenic antigen, the lymphocytes play the role of a co-factor. In newborns the thymus lymphocytes transmit substances which are necessary for the development and function of the antibody producing system.

The complicated problems of globulin synthesis in the antibody producing cell are explained in the light of the genetic theory of antibody formation advanced by Ehrich.

Relation of Antigens of Melampsora lini and Linum usitatissimum to Resistance and Susceptibility

A specific antigen was found in each of four races of Melampsora lini and four rust-differentiating varieties of Linum usitatissimum. Avirulence and virulence were related to resistance and susceptibility through the specific rust antigens. A race was virulent to varieties containing its specific rust antigen as a minor constituent, and avirulent to varieties lacking that antigen. No such correlation was found with flax antigens.