[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Inflammation](https://durgical.com/en/general-pathology/#a-inflammation) › Leukocyte recruitment: rolling, adhesion, transmigration, chemotaxis

[General pathology](https://durgical.com/en/general-pathology/) · [Inflammation](https://durgical.com/en/general-pathology/#a-inflammation)

# Leukocyte recruitment: rolling, adhesion, transmigration, chemotaxis

- Process

White cells leave the blood in steps: they roll on the vessel wall, stick firmly, squeeze between endothelial cells and crawl toward the injury.

Updated 2026-11-01

## Key points

- Order: margination → rolling (selectins) → activation (chemokines) → firm adhesion (integrins with ICAM-1/VCAM-1) → transmigration (PECAM-1) → chemotaxis.
- Selectins roll, integrins stick, PECAM-1 crosses.
- LAD type 1 = CD18 defect: delayed umbilical cord separation, infections without pus, neutrophilia.
- Chemoattractants: bacterial formyl peptides, C5a, leukotriene B4, IL-8 (CXCL8).
- Glucocorticoids and adrenaline cause neutrophilia by demargination.

## What it is

Leukocytes reach injured tissue through a multistep cascade, mostly in postcapillary venules. Selectins slow them down, chemokines switch their integrins to a high-affinity state, integrins anchor them, and PECAM-1 helps them cross the endothelium; then they follow chemical gradients. Each step has an inherited defect, which makes this a favourite exam topic.

## Key facts

- Neutrophils arrive first (6–24 hours): they are abundant, respond fast to chemokines and bind E- and P-selectin well; monocytes follow at 24–48 hours and live longer.
- Exceptions: Pseudomonas infections keep recruiting neutrophils for days; viral infections draw lymphocytes first; allergy and parasites draw eosinophils.
- L-selectin is on the leukocyte; E- and P-selectin are on the endothelium (P-selectin is stored in Weibel-Palade bodies and also found on platelets).
- Recruitment happens mainly in postcapillary venules; in the lung neutrophils also leave through capillaries.

## Step by step

- Margination: slow flow in dilated venules pushes leukocytes from the centre of the stream to the vessel wall.
- Rolling: endothelial E- and P-selectin, induced by TNF, IL-1 and histamine, bind sialyl-Lewis X on leukocytes in weak, quick bonds.
- Activation: chemokines such as IL-8 (CXCL8) displayed on endothelium switch leukocyte integrins to a high-affinity shape.
- Firm adhesion: β2 integrins (LFA-1, Mac-1) bind ICAM-1 and VLA-4 binds VCAM-1, and the cell stops.
- Transmigration (diapedesis): the cell squeezes between endothelial cells using PECAM-1 (CD31) and crosses the basement membrane with proteases.
- Chemotaxis: it crawls up gradients of bacterial formyl peptides, C5a, leukotriene B4 and IL-8.
- Activation at the site: phagocytosis, killing by reactive oxygen species and enzymes, and release of more mediators.

## Defects of recruitment and killing

| Condition | Defect | Clue |
| --- | --- | --- |
| [Leukocyte adhesion deficiency type 1](https://durgical.com/en/conditions/leukocyte-adhesion-deficiency/) | β2 integrin subunit (CD18, gene ITGB2): no firm adhesion | Delayed separation of the umbilical cord, infections without pus, very high blood neutrophil count |
| Leukocyte adhesion deficiency type 2 | No sialyl-Lewis X (fucosylation defect): no rolling | Infections as in type 1, plus Bombay blood group, short stature and intellectual disability |
| [Chédiak-Higashi syndrome](https://durgical.com/en/conditions/chediak-higashi-syndrome/) | LYST gene: faulty lysosome trafficking, giant granules | Partial albinism, recurrent pyogenic infections, neuropathy, bleeding |
| [Chronic granulomatous disease](https://durgical.com/en/conditions/chronic-granulomatous-disease/) | NADPH oxidase: no respiratory burst | Infections by catalase-positive organisms, granulomas, abnormal DHR test |
| Glucocorticoids, adrenaline | Reduced adhesion: marginated neutrophils return to the blood (demargination) | Neutrophilia without infection |

## Memory aid

Selectins Slow, Integrins Immobilise, PECAM Passes, Chemokines Call: roll, stick, slip, seek.

## Test yourself

Think of the answer, then tap the question to see it.

## Which molecules mediate the rolling of leukocytes?

Selectins: E- and P-selectin on the endothelium and L-selectin on the leukocyte, binding sialylated sugars such as sialyl-Lewis X.

## An infant has delayed umbilical cord separation, skin infections without pus and marked neutrophilia. What is the defect?

Leukocyte adhesion deficiency type 1: absent β2 integrin (CD18), so neutrophils cannot adhere firmly and leave the vessels.

## Why do glucocorticoids raise the blood neutrophil count?

They reduce adhesion molecules, so neutrophils that were stuck to vessel walls (the marginated pool) return to the circulation.

## Which molecules act as chemoattractants for neutrophils?

Bacterial N-formylmethionine peptides, complement C5a, leukotriene B4 and IL-8 (CXCL8).

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/general-pathology/leukocyte-recruitment-rolling-adhesion-transmigration-chemotaxis/)

## Related

- [Vascular changes in acute inflammation: vasodilation, leakage, exudate vs transudate](https://durgical.com/en/general-pathology/vascular-changes-in-acute-inflammation-vasodilation-leakage-exudate-vs-transudat/)
- [Mediators of inflammation: the table to know](https://durgical.com/en/general-pathology/mediators-of-inflammation-the-table-to-know/)
- [When leukocytes injure tissue: proteases, oxidants and NETs](https://durgical.com/en/general-pathology/when-leukocytes-injure-tissue-proteases-oxidants-and-nets/)
- [Inflammation: the cardinal signs and its five steps](https://durgical.com/en/general-pathology/inflammation-the-cardinal-signs-and-its-five-steps/)
- [Chronic inflammation: causes, cells and features](https://durgical.com/en/general-pathology/chronic-inflammation-causes-cells-and-features/)

## Related conditions

- [Leukocyte adhesion deficiency](https://durgical.com/en/conditions/leukocyte-adhesion-deficiency/)
- [Chédiak–Higashi syndrome](https://durgical.com/en/conditions/chediak-higashi-syndrome/)
- [Chronic granulomatous disease](https://durgical.com/en/conditions/chronic-granulomatous-disease/)
- [Hyper-IgE syndrome (Job syndrome)](https://durgical.com/en/conditions/hyper-ige-syndrome/)
- [Abscess, furuncle and carbuncle](https://durgical.com/en/conditions/abscess-furuncle-and-carbuncle/)
- [Acute appendicitis](https://durgical.com/en/conditions/acute-appendicitis/)
- [Community-acquired pneumonia](https://durgical.com/en/conditions/community-acquired-pneumonia/)

## Elsewhere in DurgiPedia

- [Neutrophil](https://durgical.com/en/immunology/neutrophil/)
- [Phagocyte defects: CGD, LAD, Chédiak–Higashi](https://durgical.com/en/immunology/phagocyte-defects-cgd-lad-chediak-higashi/)
- [IL-8 and the chemokines](https://durgical.com/en/immunology/il-8-and-the-chemokines/)
- [Phagocytosis and the respiratory burst](https://durgical.com/en/immunology/phagocytosis-and-the-respiratory-burst/)
- [Lymphocyte recirculation and homing](https://durgical.com/en/immunology/lymphocyte-recirculation-and-homing/)
- [Complement: three pathways, MAC, regulators](https://durgical.com/en/immunology/complement-three-pathways-mac-regulators/)

## In Pharmacology

- [Corticosteroids (glucocorticoids)](https://durgical.com/en/pharmacology/classes/corticosteroids/)

[← All of general pathology](https://durgical.com/en/general-pathology/)

Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Leukocyte adhesion deficiency type 1: MedlinePlus Genetics](https://medlineplus.gov/genetics/condition/leukocyte-adhesion-deficiency-type-1/) (MedlinePlus, US National Library of Medicine, 2026); [Chronic granulomatous disease: MedlinePlus Genetics](https://medlineplus.gov/genetics/condition/chronic-granulomatous-disease/) (MedlinePlus, US National Library of Medicine, 2026); [17.5 Inflammation and Fever](https://openstax.org/books/microbiology/pages/17-5-inflammation-and-fever) (OpenStax (Microbiology), 2016).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/general-pathology/leukocyte-recruitment-rolling-adhesion-transmigration-chemotaxis/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/leukocyte-recruitment-rolling-adhesion-transmigration-chemotaxis/