Semaphorin-4A Antibodies

Semaphorin-4A (Sema4a)

Cell surface receptor for PLXNB1, PLXNB2, PLXNB3 and PLXND1 that plays an significant role in cell-cell signaling. Plays a role in priming antigen-specific T-cells, promotes differentiation of Th1 T-helper cells, and thus contributes to adaptive immunity.

Promotes phosphorylation of TIMD2. Inhibits angiogenesis.

Gene Information

Mouse
Gene Name:	Sema4a
Uniprot:	Q62178
Entrez:	20351

Family

Belongs to:
semaphorin family

Alternative Names

CORD10; RP35; Sema B; sema domain, immunoglobulin domain (Ig), transmembrane domain (TM) and shortcytoplasmic domain, (semaphorin) 4A; SEMA4A; SEMAB; Semaphorin 4A; semaphorin-4A; semaphorin-B; SEMB; SEMBFLJ12287

Molecular Weight

Mass (kDA):
83.421 kDA

Genomic Context

Mouse
Location:	3|3 F1
Sequence:	3;

Diseases

• Nervousness
• Retinal Degeneration
• Autoimmune Reaction
• Tumor Angiogenesis
• Autoimmune Diseases
• Retinitis Pigmentosa
• Experimental Autoimmune Encephalomyelitis
• Autoimmunity
• Inflammation
• Communicable Diseases
• Asthma

• Multiple Sclerosis
• Encephalomyelitis
• Sclerosis
• Brain Ischemia
• Fracture Of First Cervical Vertebra
• Hypoxia

Pathways

• Immune Response
• Axon Guidance
• Cell Activation
• Angiogenesis
• Cell Migration
• T Cell Activation
• Cell Death
• Pathogenesis
• Cell Adhesion
• Response To Lipopolysaccharide
• Circadian Rhythm
• Signal Transmission
• Localization

• Macrophage Activation
• Inflammatory Response
• Response To Oxidative Stress
• Regeneration
• Endothelial Cell Migration
• Phagocytosis
• Cell Differentiation

PTMs

• Disulfide bond

• Glycoprotein

Research Areas

• Neuroscience
• Vision

For details, visit:
bosterbio.com/bosterbio-gene-info-cards/Sema4a

Best Uses Of The SEMA4A Marker

This article will demonstrate how to use the SEMA4A marker for detecting YF antibodies and expressions in DLNs. Next, you will learn how to use DAPI staining for SEMA4A detection in DLNs. These tips will allow you to make the most of the marker, and save time in your research.

Expression of SEMA4A in YF antibodies and corresponding YF antibody values

We found that mice who had received prior JE vaccinations had higher YF antibody levels and increased expression of the semaphorin genes in monocytes. This finding suggests that cross-reactive antibodies may affect the efficacy of YF vaccination when there is no cellular immune response to JE. The YF17D virus was opsonized with murine-human chimeric anti 4G2. This significantly increased the expression of semaphorin genes in monocyte-derived DCs.

PRNT was used for the determination of anti-JE titres. The 99% confidence interval for the mean titre in Group 4 is shown by the dotted line. This group had higher Anti-JE titres that the mean compared to the control group. To investigate this hypothesis, the pre-vaccination immune sera were diluted 1:10 and incubated with YF17D prior to infecting THP-1 monocytes. Pre-vaccination serum mediated YF17D infection. Log-transformed log-transformed YF antibodies were correlated to YF17D disease.

In a separate research, we explored the relationship between YF antibody levels and RNA levels within peripheral blood from YF-immunized mouse. The study was conducted using a systems biology approach. Data were analyzed using a non-targeted method. Our analysis identified over 1,100 significantly different features. These include the aminoacyl-RNA–tRNA biosynthesis pathway as well as linoleic Acid biosynthesis.

Cross-reactive antibodies were responsible for the YF vaccine-induced inflammatory response in mice. These antibodies promote YF virus infection and lead to prolonged viremia. By contrast, in the control group, the YF antibody titres were significantly lower than in the enhancing group. The results suggest that cross reactive antibodies are responsible to enhanced viremia as well as improved antigenicity.

Although this study shows a correlation between YF antibody levels and SEMA4A markers expression in DCs (as shown in the study), further research is needed to validate these findings. Immune semaphorins regulate immune cell interaction and trafficking. This induction may have increased the YF vaccination's ability of infecting T cells. Further research is needed before we can determine if semaphorin induction increases T-cell interaction.

SEMA4A DAPI staining

DAPI staining for SEMA4, a nuclear proteins, is often used in immunofluorescence studies. The anti-SEMA4A antibody, A17205, can be used at a dilution rate of 1:100. Other staining agents, DAPI and PE-Cy7 are household products that are less specific. In this case, SEMA4A was also stained.

SEMA4A is highly expressed on DCs, indicating that it may co-stimulate T-cell responses. CD45RO+CD45RA+naive CD4+ CD4+ T cell were labeled using CFSE and stimulated by an anti-CD3 Ab in the presence Sema4A+-transfected L-cells. Controls were L cells that had not been infected. After stimulation, SEMA4AFc protein-expressing CD4+ cells multiplied intracellularly.

The study revealed that Sema4A plays a role in two distinct pathways of SSc pathogenesis. These are inflammatory response and fibrosis. Sema4A has been implicated in both pathways. Blocking Sema4A signaling can suppress both of these pathologies. SSc is still difficult to treat and currently there are no approved drugs that directly target the fibrotic process.

DAPI is a powerful fluorescent stain for DNA and can be used in a variety of cell types to detect SEMA4A. DAPI binds to DNA and RNA. It can also pass through intact cell walls. In a fluorescent assay, DAPI is most effective when used with green or red fluorescent molecules. A DAPI-labeled cell is an indicator of membrane viability.

Recent research has implicated Sema4A in several immune-mediated conditions. Recent research has revealed that SEMA4A also exists in germinal centre B cells and activated t cells. It has been implicated also in the development allergic asthma. Sema4A can be expressed by activated T cells. This helps them mature and bind to the Tim-2 or ILT-4 receptors.

Despite the positive effects of Sema4A on Tregs, it was also found that removing the receptor for Tregs by genetics weakened the protective effect of the protein. Sema4A was also found to reduce tubular injury in IRI mice, and decrease serum creatinine. These results were not replicated in human renals so it is not known if it is an accurate indicator for renal apoptosis.

DAPI staining on SEMA4A in DLNs

DAPI, or 4',6-diamidino-2-phenylindole, is a blue fluorescent dye that binds to the AT region of dsDNA. DAPI can increase fluorescence 20-fold when excited by a violet (405nm laser line). DAPI is a common nuclear counterstain in fluorescence microscopy and flow cytometry, and is suitable for use with green, red, or rhodamine dyes.

DAPI can be used to visualize cellular granules. It has been proven to be sensitive in identifying and fingerprinting PAOs across a variety of environments. It is also useful in staining living cells. Here, we present the results for DAPI-stained DLNs PAOs. Because it can be used in single-cell analysis, DAPI is a practical technique.

Primary immune responses can be initiated by DCs. The expression of semaphorin genes was significantly elevated in monocyte-derivedDCs after YF17D infections. YF17D virus was opsonized using mouse-human chimeric anti 4G2 and SEMA4A in THP-1 monocytes.

Another study showed that the semaphorin VEGF165 was injected at 50 ng/mL into THP-1 cells. The anti-VEGF-biotin antibody detected it. Sema4a and Sema4d were compared to ITGA1, Sema3aFc and Sema4d. SEMA4A was stained with the Abscam antibody, followed by DAPI staining.

On sludge samples that were grown in acetate media for four hours, DAPI staining took place. The top 1,2% showed an increase in polyP fluorescence. Each plot was made with 10,000 cells and a gate that represented the percentage of cells in it. When DAPI was used for fluorescent markers, the top 1% showed significant increases in the fluorescence of polyP.

The pDC mediated antitumor immune responses are strongly correlated with Nrp1-induced SEMA4a stabilit. These observations may be attributed to the ability of Nrp1 to induce Treg stability, a major barrier to anti-tumor immunity. This gene may also help prevent autoimmune or inflammatory adverse events. It is possible Nrp1 is a therapeutic target by Sema4a at DLNs.

DAPI staining SEMA4A with low concentrations of JE IgG antibody in DLNs

We studied the effects JE IgG antibodies had on total and activated DCs of a mouse model of YF. We used a serum made from BHK-21 cells. Then, we serially diluted a concentration of JE IgG antibodies in PBS containing 1% BSA. Cells were then stained using antibodies against CD11c-Pacific Blue, CD80-BV605 and CD86-BV510. SEMA4A from Abcam was also used to stain these cells. To detect SEMA4A from LN samples, we also used a secondary antibody against AlexaFluor488. After staining was complete, cells were fixed in 4% paraformaldehyde.

DCs play an important part in initiating primary immune reactions. Interestingly, YF17D virus opsonized with mouse-human chimeric antibodies 4G2 increases SEMA4A protein expression in monocyte-derived DCs. DCs that express semaphorin also increased significantly. These results suggest that JE immunizations prior to YF vaccinations can induce an adaptive immune reaction in immunologically naive rodents.

Increasing cross-reactive antibodies titres in DLNs facilitated DC migration and activation, which both contribute to enhanced immunogenicity. The activation or FcgRs might be responsible for DCs' higher immunogenicity. It is still unclear what mechanism is responsible for the increased immunogenicity. It could be that the immune semaphorin level is increased by increasing cross-reactive antibodies.

Increasing the titres for cross-reactive antibodies prolonged YF-vaccine viremia and induced more pro-inflammatory response. Increased titres of these antibodies led to the production adhesion molecules that are intrinsically linked to activation in the Fcc-receptor pathway. Furthermore, these antibodies induce immune semaphorins, a protein that facilitates immune cell interaction and trafficking. These results strongly suggest the efficacy of YF vaccines.

DAPI staining SEMA4.A at low concentrations JE IgG antibody in DLNs shows that the underlying immune system is heavily dependent on JE IgG. Positive correlations between the antibody responses of YF and SEMA4A were observed for the semaphorin related pathway gene YF.